Dataset Viewer
id
stringlengths 3
9
| title
stringlengths 17
374
| contents
stringlengths 3
1.81k
|
|---|---|---|
0_0
|
bronchopulmonary-dysplasia-bpd-prevention - SUMMARY AND RECOMMENDATIONS
|
●Definition– Clinically, BPD is defined as an ongoing need for supplemental oxygen and/or respiratory support at either 28 days postnatal age or 36 weeks postmenstrual age (calculator 1) in a preterm neonate with radiographic evidence of parenchymal lung disease (image 1). Various criteria are used to define BPD (table 2). (See'Terminology'above.)
|
0_1
|
bronchopulmonary-dysplasia-bpd-prevention - SUMMARY AND RECOMMENDATIONS
|
ung disease (image 1). Various criteria are used to define BPD (table 2). (See'Terminology'above.) ●Effective interventions– Interventions that are effective for reducing the risk of bronchopulmonary dysplasia (BPD) in extremely preterm (EPT) infants (gestational age [GA] <28 weeks) who are at risk for BPD include (algorithm 1) (see'Our approach'above and'Interventions'above): •Antenatal glucocorticoid therapy– Antenatal glucocorticoid therapy for pregnant individuals <34 weeks gestation who are at high risk for preterm delivery, which is discussed in detail separately.
|
0_2
|
bronchopulmonary-dysplasia-bpd-prevention - SUMMARY AND RECOMMENDATIONS
|
weeks gestation who are at high risk for preterm delivery, which is discussed in detail separately. (See"Antenatal corticosteroid therapy for reduction of neonatal respiratory morbidity and mortality from preterm delivery".) •Nutrition and fluid management– In all preterm infants, nutritional goals are set to provide adequate caloric intake to promote somatic and lung growth, and fluid intake is adjusted to maintain neutral or slightly negative water balance. Mother's breast milk is the preferred nutritional source, and if not available, donor breast milk is used. These issues are discussed separately.
|
0_3
|
bronchopulmonary-dysplasia-bpd-prevention - SUMMARY AND RECOMMENDATIONS
|
onal source, and if not available, donor breast milk is used. These issues are discussed separately. (See"Approach to enteral nutrition in the premature infant"and"Parenteral nutrition in premature infants"and"Fluid and electrolyte therapy in newborns"and"Human milk feeding and fortification of human milk for premature infants"and"Respiratory distress syndrome (RDS) in preterm neonates: Management", section on 'Fluid management'.) •Oxygen targets– In preterm infants who require supplemental oxygen, target oxygen saturation (SpO2) levels are set for values between 90 and 95 percent, as discussed separately.
|
0_4
|
bronchopulmonary-dysplasia-bpd-prevention - SUMMARY AND RECOMMENDATIONS
|
ygen saturation (SpO2) levels are set for values between 90 and 95 percent, as discussed separately. (See"Neonatal target oxygen levels for preterm infants", section on 'Oxygen target levels'.) •Ventilation strategies that minimize lung injury– Use of ventilation strategies that minimize lung injury, including preferential use of noninvasive modalities. The approach to mechanical ventilation in preterm infants is summarized in the table (table 3) and discussed in detail separately. (See"Respiratory distress syndrome (RDS) in preterm neonates: Management", section on 'Clinical approach'and"Approach to mechanical ventilation in very preterm neonates".)
|
0_5
|
bronchopulmonary-dysplasia-bpd-prevention - SUMMARY AND RECOMMENDATIONS
|
t", section on 'Clinical approach'and"Approach to mechanical ventilation in very preterm neonates".) •Caffeinetherapy– Earlycaffeinetherapy is routinely given to all EPT infants, as discussed separately. (See"Management of apnea of prematurity", section on 'Caffeine'.) •Vitamin Asupplementation– The use ofvitamin Asupplementation is center-dependent. If vitamin A is available, practitioners may consider its administration to EPT infants who require ventilatory support; however, the relative benefit of vitamin A supplementation in this setting appears to be small. (See'Vitamin A'above.)
|
0_6
|
bronchopulmonary-dysplasia-bpd-prevention - SUMMARY AND RECOMMENDATIONS
|
ive benefit of vitamin A supplementation in this setting appears to be small. (See'Vitamin A'above.) •Postnatal glucocorticoids– We donotroutinely administer postnatal systemic or inhaled glucocorticoids to prevent BPD. Systemic glucocorticoids are reserved for EPT infants who remain ventilator-dependent and/or require oxygen supplementation >50 percent at a postnatal age of two to four weeks. This is discussed in detail separately. (See"Postnatal use of glucocorticoids for prevention of bronchopulmonary dysplasia (BPD) in preterm infants".)
|
0_7
|
bronchopulmonary-dysplasia-bpd-prevention - SUMMARY AND RECOMMENDATIONS
|
atal use of glucocorticoids for prevention of bronchopulmonary dysplasia (BPD) in preterm infants".) ●Ineffective interventions– Interventions that do not appear to be effective for prevention of BPD in EPT infants include (see'Unproven interventions'above): •Sustained lung inflation during neonatal resuscitation (see"Neonatal resuscitation in the delivery room", section on 'Sustained inflation') •Inhaled nitric oxide (iNO) (see"Respiratory distress syndrome (RDS) in preterm neonates: Management", section on 'Limited role for inhaled nitric oxide') •Late surfactant therapy (see"Respiratory distress syndrome (RDS) in preterm neonates: Management", section on 'Timing')
|
1_0
|
bronchopulmonary-dysplasia-bpd-prevention - INTRODUCTION
|
Bronchopulmonary dysplasia (BPD; also known as neonatal chronic lung disease [CLD]) is a major cause of respiratory illness in preterm infants. It is an important contributing factor in the increased risk of mortality and morbidity in the preterm population. This topic will provide an overview of strategies used to prevent BPD. Other related topics include: ●(See"Antenatal corticosteroid therapy for reduction of neonatal respiratory morbidity and mortality from preterm delivery".) ●(See"Postnatal use of glucocorticoids for prevention of bronchopulmonary dysplasia (BPD) in preterm infants".)
|
1_1
|
bronchopulmonary-dysplasia-bpd-prevention - INTRODUCTION
|
atal use of glucocorticoids for prevention of bronchopulmonary dysplasia (BPD) in preterm infants".) ●(See"Bronchopulmonary dysplasia (BPD): Clinical features and diagnosis".) ●(See"Bronchopulmonary dysplasia (BPD): Management and outcome".) ●(See"Complications and long-term pulmonary outcomes of bronchopulmonary dysplasia".) ●(See"Pulmonary hypertension associated with bronchopulmonary dysplasia".)
|
2_0
|
bronchopulmonary-dysplasia-bpd-prevention - TERMINOLOGY
|
●Prematurity– Different degrees of prematurity are defined by gestational age (GA), which is calculated from the first day of the mother's last period, or birth weight (BW), as summarized in the table (table 1) and discussed in detail separately. (See"Preterm birth: Definitions of prematurity, epidemiology, and risk factors for infant mortality", section on 'Definitions'.) ●BPD– BPD is a chronic lung disease characterized by disruption of pulmonary development and/or lung injury in the context of preterm birth.
|
2_1
|
bronchopulmonary-dysplasia-bpd-prevention - TERMINOLOGY
|
acterized by disruption of pulmonary development and/or lung injury in the context of preterm birth. Clinically, BPD is defined as an ongoing need for supplemental oxygen and/or respiratory support at either 28 days postnatal age or 36 weeks postmenstrual age (calculator 1) in a preterm neonate with radiographic evidence of parenchymal lung disease (image 1). Various criteria are used to define BPD, as summarized in the (table 2) and discussed in detail separately. (see"Bronchopulmonary dysplasia (BPD): Clinical features and diagnosis", section on 'Definitions and severity of BPD').
|
3_0
|
bronchopulmonary-dysplasia-bpd-prevention - OUR APPROACH
|
The following is a summary of the strategies that we use to reduce the incidence of BPD in infants who are at risk for developing BPD. The combination of interventions addresses the multiple risk factors implicated in the pathogenesis of BPD (algorithm 1). (See"Bronchopulmonary dysplasia (BPD): Clinical features and diagnosis", section on 'Risk factors'.)
|
4_0
|
bronchopulmonary-dysplasia-bpd-prevention - OUR APPROACH - Initial general measures
|
General measures are provided to all infants who are at risk for BPD (extremely preterm [EPT] infant, gestational age <28 weeks). General measures are provided to all infants who are at risk for BPD (extremely preterm [EPT] infant, gestational age <28 weeks). ●Antenatal steroids – Antenatal glucocorticoids are appropriate for pregnant woman at 23 to 34 weeks of gestation at high risk for preterm delivery within the next seven days. This is discussed separately. (See"Antenatal corticosteroid therapy for reduction of neonatal respiratory morbidity and mortality from preterm delivery".)
|
4_1
|
bronchopulmonary-dysplasia-bpd-prevention - OUR APPROACH - Initial general measures
|
eroid therapy for reduction of neonatal respiratory morbidity and mortality from preterm delivery".) ●Fluid management – After the first week of life, fluid intake is generally restricted to 130 to 140 mL/kg per day to maintain neutral or slightly negative fluid balance. Fluid status and nutritional status is monitored frequently, and fluid intake modified to avoid dehydration and overhydration and to ensure adequate growth. (See"Respiratory distress syndrome (RDS) in preterm neonates: Management", section on 'Fluid management'.) ●Nutrition – In our centers, nutritional goals are set to provide adequate caloric intake to promote somatic and lung growth [1].
|
4_2
|
bronchopulmonary-dysplasia-bpd-prevention - OUR APPROACH - Initial general measures
|
nutritional goals are set to provide adequate caloric intake to promote somatic and lung growth [1]. Mother's breast milk is the preferred nutritional source, and if not available, we use donor breast milk. (See"Approach to enteral nutrition in the premature infant".) ●Caffeine– We administer caffeine to all EPT infants within the first 24 hours of life. These neonates have the highest risk for BPD. (See"Management of apnea of prematurity", section on 'Caffeine'.) ●Vitamin A– One of the authors of this topic routinely uses vitamin A (if available) in ventilator-dependent extremely low birth weight (ELBW) infants (birth weight <1000 g). (See'Vitamin A'below.)
|
5_0
|
bronchopulmonary-dysplasia-bpd-prevention - OUR APPROACH - Respiratory support
|
The goal for respiratory support for infants at risk for BPD is to maintain adequate oxygenation and ventilation while minimizing respiratory intervention that may lead to lung injury. Our approach is briefly summarized here. These interventions are discussed in greater detail separately. (See The goal for respiratory support for infants at risk for BPD is to maintain adequate oxygenation and ventilation while minimizing respiratory intervention that may lead to lung injury. Our approach is briefly summarized here. These interventions are discussed in greater detail separately.
|
5_1
|
bronchopulmonary-dysplasia-bpd-prevention - OUR APPROACH - Respiratory support
|
approach is briefly summarized here. These interventions are discussed in greater detail separately. (See "Respiratory distress syndrome (RDS) in preterm neonates: Management" and "Approach to mechanical ventilation in very preterm neonates" .) ●In infants who require supplemental oxygen, we set a peripheral oxygen saturation (SpO2) target range of 90 to 95 percent. (See'Ventilation strategies to minimize lung injury'below and"Neonatal target oxygen levels for preterm infants".) ●In most preterm infants, we use early positive airway pressure support (typically with continuous positive airway pressure [CPAP]).
|
5_2
|
bronchopulmonary-dysplasia-bpd-prevention - OUR APPROACH - Respiratory support
|
early positive airway pressure support (typically with continuous positive airway pressure [CPAP]). (See"Respiratory distress syndrome (RDS) in preterm neonates: Management", section on 'Early positive pressure'.) ●In preterm infants who require intubation soon after birth, we provide early surfactant therapy. (See"Respiratory distress syndrome (RDS) in preterm neonates: Management", section on 'Surfactant therapy'.) ●In preterm infants with respiratory failure, we use a mechanical ventilation strategy that aims to minimize ventilator-induced lung injury (VILI). The approach is summarized in the table (table 3) and is discussed in detail separately.
|
5_3
|
bronchopulmonary-dysplasia-bpd-prevention - OUR APPROACH - Respiratory support
|
ry (VILI). The approach is summarized in the table (table 3) and is discussed in detail separately. (See"Approach to mechanical ventilation in very preterm neonates", section on 'Clinical approach'.) ●In infants with severe persistent respiratory failure despite optimal settings on conventional ventilation, a trial of high-frequency ventilation (HFV) is used to minimize VILI. This is discussed separately. (See"Approach to mechanical ventilation in very preterm neonates", section on 'Transition to HFV'.) The role that mechanical ventilation and oxygen toxicity play in the pathogenesis of BPD is discussed separately.
|
5_4
|
bronchopulmonary-dysplasia-bpd-prevention - OUR APPROACH - Respiratory support
|
mechanical ventilation and oxygen toxicity play in the pathogenesis of BPD is discussed separately. (See"Bronchopulmonary dysplasia (BPD): Clinical features and diagnosis", section on 'Postnatal risk factors'.)
|
6_0
|
bronchopulmonary-dysplasia-bpd-prevention - OUR APPROACH - Postnatal glucocorticoids
|
We do We do not routinely administer postnatal systemic or inhaled glucocorticoids to prevent BPD. Systemic glucocorticoids are reserved for EPT infants who remain ventilator-dependent and/or require oxygen supplementation >50 percent at two to four weeks postnatal age. This is discussed in detail separately. (See "Postnatal use of glucocorticoids for prevention of bronchopulmonary dysplasia (BPD) in preterm infants" .)
|
8_0
|
bronchopulmonary-dysplasia-bpd-prevention - INTERVENTIONS - Overview
|
●Measures that are routinely used– The following interventions are generally used in combination to improve outcomes (including a reduction in the risk of BPD) in at-risk preterm infants, especially extremely preterm infants (EPT; gestational age [GA] <28 weeks) (algorithm 1): •Antenatal glucocorticoid therapy (see"Antenatal corticosteroid therapy for reduction of neonatal respiratory morbidity and mortality from preterm delivery").
|
8_1
|
bronchopulmonary-dysplasia-bpd-prevention - INTERVENTIONS - Overview
|
eroid therapy for reduction of neonatal respiratory morbidity and mortality from preterm delivery"). •Protective ventilatory strategies that minimize barotrauma or volutrauma in infants who require respiratory support for neonatal respiratory distress (RDS) (table 3) (see"Respiratory distress syndrome (RDS) in preterm neonates: Management", section on 'Early positive pressure'and"Approach to mechanical ventilation in very preterm neonates"). •Mother's breast milk (see"Approach to enteral nutrition in the premature infant"and"Infant benefits of breastfeeding"). •Caffeine(see"Management of apnea of prematurity", section on 'Caffeine').
|
8_2
|
bronchopulmonary-dysplasia-bpd-prevention - INTERVENTIONS - Overview
|
efits of breastfeeding"). •Caffeine(see"Management of apnea of prematurity", section on 'Caffeine'). •Modest fluid restriction (see"Fluid and electrolyte therapy in newborns"and"Respiratory distress syndrome (RDS) in preterm neonates: Management", section on 'Fluid management'). ●Measures that are used selectively– Preterm infants who remain ventilator-dependent at one week after birth are at high risk for developing BPD. Such neonates may benefit from additional preventive measures, including: •Selective us of postnatal glucocorticoid therapy in high-risk EPT infants (see"Postnatal use of glucocorticoids for prevention of bronchopulmonary dysplasia (BPD) in preterm infants").
|
8_3
|
bronchopulmonary-dysplasia-bpd-prevention - INTERVENTIONS - Overview
|
atal use of glucocorticoids for prevention of bronchopulmonary dysplasia (BPD) in preterm infants"). •Some centers usevitamin Asupplementation (if available) in EPT infants who require mechanical ventilation support (see'Vitamin A'below). •Selective use of a trial of diuretic therapy (see"Bronchopulmonary dysplasia (BPD): Management and outcome", section on 'Diuretics'and"Respiratory distress syndrome (RDS) in preterm neonates: Management", section on 'Fluid management'). ●Measures that are not used– These include: •Routine use of postnatal glucocorticoid therapy in all at-risk preterm infants.
|
8_4
|
bronchopulmonary-dysplasia-bpd-prevention - INTERVENTIONS - Overview
|
sed– These include: •Routine use of postnatal glucocorticoid therapy in all at-risk preterm infants. This is because of concerns of adverse effects, particularly adverse neurodevelopmental outcome, with early glucocorticoid therapy, as discussed separately. (See"Postnatal use of glucocorticoids for prevention of bronchopulmonary dysplasia (BPD) in preterm infants", section on 'Adverse effects'.) •Routine use ofinhaled nitric oxide(iNO), since this does not appear to be effective. (See"Respiratory distress syndrome (RDS) in preterm neonates: Management", section on 'Limited role for inhaled nitric oxide'.) •Late surfactant administration, since this does not appear to be effective.
|
8_5
|
bronchopulmonary-dysplasia-bpd-prevention - INTERVENTIONS - Overview
|
inhaled nitric oxide'.) •Late surfactant administration, since this does not appear to be effective. (See"Respiratory distress syndrome (RDS) in preterm neonates: Management", section on 'Timing'.) •Use of bronchodilators, since limited evidence did not show efficacy. (See'Unproven interventions'below.)
|
10_0
|
bronchopulmonary-dysplasia-bpd-prevention - INTERVENTIONS - Glucocorticoids - -Antenatal glucocorticoids
|
Antenatal glucocorticoid therapy is an effective intervention for prevention of respiratory distress syndrome (RDS) resulting in less need for mechanical ventilation and oxygen supplementation (risk factors for BPD). Antenatal glucocorticoids are appropriate for pregnant individuals from 23 to 34 weeks of gestation who are at risk for preterm delivery within the next seven days. This is discussed separately.
|
10_1
|
bronchopulmonary-dysplasia-bpd-prevention - INTERVENTIONS - Glucocorticoids - -Antenatal glucocorticoids
|
ation who are at risk for preterm delivery within the next seven days. This is discussed separately. (See Antenatal glucocorticoid therapy is an effective intervention for prevention of respiratory distress syndrome (RDS) resulting in less need for mechanical ventilation and oxygen supplementation (risk factors for BPD). Antenatal glucocorticoids are appropriate for pregnant individuals from 23 to 34 weeks of gestation who are at risk for preterm delivery within the next seven days. This is discussed separately. (See "Antenatal corticosteroid therapy for reduction of neonatal respiratory morbidity and mortality from preterm delivery" .)
|
11_0
|
bronchopulmonary-dysplasia-bpd-prevention - INTERVENTIONS - Glucocorticoids - -Postnatal glucocorticoids
|
We do We do not routinely administer postnatal systemic or inhaled glucocorticoids to prevent BPD. Systemic glucocorticoids are reserved for EPT infants who remain ventilator-dependent and/or require oxygen supplementation >50 percent at a postnatal age of two to four weeks. This is discussed in detail separately. (See "Postnatal use of glucocorticoids for prevention of bronchopulmonary dysplasia (BPD) in preterm infants" .)
|
12_0
|
bronchopulmonary-dysplasia-bpd-prevention - INTERVENTIONS - Surfactant
|
Exogenous surfactant therapy given within the first 30 to 60 minutes after birth is effective in the prevention and treatment of RDS and reduces the need for mechanical ventilation and oxygen supplementation (risk factors for BPD). The use of early surfactant to prevent and treat RDS is discussed separately. (See Exogenous surfactant therapy given within the first 30 to 60 minutes after birth is effective in the prevention and treatment of RDS and reduces the need for mechanical ventilation and oxygen supplementation (risk factors for BPD).
|
12_1
|
bronchopulmonary-dysplasia-bpd-prevention - INTERVENTIONS - Surfactant
|
S and reduces the need for mechanical ventilation and oxygen supplementation (risk factors for BPD). The use of early surfactant to prevent and treat RDS is discussed separately. (See "Respiratory distress syndrome (RDS) in preterm neonates: Management", section on 'Surfactant therapy' .)
|
13_0
|
bronchopulmonary-dysplasia-bpd-prevention - INTERVENTIONS - Fluid management
|
The goal of fluid management is to maintain neutral or slightly negative fluid balance. Our usual practice is to restrict total fluid intake to 130 to 140 mL/kg per day after the first week of life. However, the fluid status of the patient must be monitored frequently to avoid dehydration or overhydration as fluid needs widely vary in preterm infants due to differences in insensible fluid loss. Caloric intake and growth should be closely monitored. (See The goal of fluid management is to maintain neutral or slightly negative fluid balance.
|
13_1
|
bronchopulmonary-dysplasia-bpd-prevention - INTERVENTIONS - Fluid management
|
itored. (See The goal of fluid management is to maintain neutral or slightly negative fluid balance. Our usual practice is to restrict total fluid intake to 130 to 140 mL/kg per day after the first week of life. However, the fluid status of the patient must be monitored frequently to avoid dehydration or overhydration as fluid needs widely vary in preterm infants due to differences in insensible fluid loss. Caloric intake and growth should be closely monitored. (See "Fluid and electrolyte therapy in newborns" .) The available evidence does not support the routine use of diuretic therapy in maintaining a neutral or negative fluid balance to prevent BPD.
|
13_2
|
bronchopulmonary-dysplasia-bpd-prevention - INTERVENTIONS - Fluid management
|
e routine use of diuretic therapy in maintaining a neutral or negative fluid balance to prevent BPD. However, it may be reasonable to selectively use diuretic therapy as a trial in chronically ventilator-dependent infants with moderate to severe pulmonary impairment despite adequate fluid restriction. This is discussed in greater detail separately. (See"Respiratory distress syndrome (RDS) in preterm neonates: Management", section on 'Fluid management'.) Use of diuretics in the management of infants with established BPD is discussed separately. (See"Bronchopulmonary dysplasia (BPD): Management and outcome", section on 'Diuretics'.)
|
14_0
|
bronchopulmonary-dysplasia-bpd-prevention - INTERVENTIONS - Ventilation strategies to minimize lung injury
|
Mechanical ventilation (MV) has been a lifesaving intervention in the care of preterm infants at risk for RDS due to premature lung development. However, mechanical ventilation causes tissue injury and inflammation due to volutrauma that contributes to BPD. As a result, MV strategies aim to minimize lung injury while achieving adequate oxygenation and ventilation. These strategies include: Mechanical ventilation (MV) has been a lifesaving intervention in the care of preterm infants at risk for RDS due to premature lung development.
|
14_1
|
bronchopulmonary-dysplasia-bpd-prevention - INTERVENTIONS - Ventilation strategies to minimize lung injury
|
aving intervention in the care of preterm infants at risk for RDS due to premature lung development. However, mechanical ventilation causes tissue injury and inflammation due to volutrauma that contributes to BPD. As a result, MV strategies aim to minimize lung injury while achieving adequate oxygenation and ventilation. These strategies include: ●Avoidance of MV through preferential use of noninvasive respiratory support (eg, nasal continuous positive airway pressure [nCPAP]) when possible. (See"Respiratory distress syndrome (RDS) in preterm neonates: Management", section on 'Early positive pressure'.) ●Use of volume-targeted ventilation (VTV) using low tidal volumes (4 to 6 mL/kg).
|
14_2
|
bronchopulmonary-dysplasia-bpd-prevention - INTERVENTIONS - Ventilation strategies to minimize lung injury
|
sitive pressure'.) ●Use of volume-targeted ventilation (VTV) using low tidal volumes (4 to 6 mL/kg). (See"Approach to mechanical ventilation in very preterm neonates", section on 'Clinical approach'.) ●Use of high-frequency oscillatory or jet ventilation (HFOV or HFJV) as a rescue therapy. (See"Approach to mechanical ventilation in very preterm neonates", section on 'Transition to HFV'.) The approach is summarized in the table (table 3), and discussed in greater detail separately. (See"Approach to mechanical ventilation in very preterm neonates".)
|
15_0
|
bronchopulmonary-dysplasia-bpd-prevention - INTERVENTIONS - Caffeine
|
For most ELBW infants (BW <1000 g), we suggest prophylactic For most ELBW infants (BW <1000 g), we suggest prophylactic caffeine starting on the first day of life. The available clinical trial data suggest this intervention is safe and effective for reducing BPD and perhaps other long-term complications. This is discussed separately. (See "Management of apnea of prematurity", section on 'Caffeine' .)
|
16_0
|
bronchopulmonary-dysplasia-bpd-prevention - INTERVENTIONS - Vitamin A
|
EPT infants may have EPT infants may have vitamin A deficiency, which may promote the development of BPD [ 2 ]. However, data are conflicting as to whether vitamin A supplementation reduces the incidence of BPD. If there is a benefit, it appears to be modest. Since the incidence of BPD varies among neonatal intensive care units (NICUs), the decision to usevitamin Asupplementation may depend upon the local incidence of BPD and the availability and cost of the drug [3].
|
16_1
|
bronchopulmonary-dysplasia-bpd-prevention - INTERVENTIONS - Vitamin A
|
ementation may depend upon the local incidence of BPD and the availability and cost of the drug [3]. For example, one of the authors of this topic routinely uses vitamin A supplementation at their center as a preventive measure in EPT infants who require mechanical ventilation (if the drug is available); whereas the other author does not routinely use it at their center. At most centers where vitamin A is used, its use is limited to EPT infants who require mechanical ventilation. Whenvitamin Ais given, it is administered within 24 hours after birth as an intramuscular (IM) injection of 5000 international units. This dose is then provided three times per week for four weeks.
|
16_2
|
bronchopulmonary-dysplasia-bpd-prevention - INTERVENTIONS - Vitamin A
|
jection of 5000 international units. This dose is then provided three times per week for four weeks. Enteral water-solublevitamin Aisnotused for this purpose because, although it may increases plasma retinol levels in EPT infants [4,5], it does not appear to reduce the severity of BPD [4-6]. Evidence supporting IMvitamin Asupplementation includes the following: ●In a meta-analysis of five trials (884 neonates), IMvitamin Asupplementation compared with control modestly reduced rates of BPD; however, the finding did not achieve statistical significance (68 versus 74 percent; relative risk [RR] 0.93, 95% CI 0.86-1.01) [7].
|
16_3
|
bronchopulmonary-dysplasia-bpd-prevention - INTERVENTIONS - Vitamin A
|
ieve statistical significance (68 versus 74 percent; relative risk [RR] 0.93, 95% CI 0.86-1.01) [7]. ●A subsequent multicenter retrospective study from the Pediatrix Medical Group of neonates from 2010 to 2012 reported that the shortage ofvitamin Ain the United States that began in 2010 did not affect the incidence of mortality or BPD in the participating NICUs [8]. During the study period, vitamin A supplementation in patients decreased from a level of 27 percent to 2 percent as the supply of vitamin decreased. A multivariable analysis demonstrated that vitamin A supplementation was not an independent risk factor for death or BPD.
|
16_4
|
bronchopulmonary-dysplasia-bpd-prevention - INTERVENTIONS - Vitamin A
|
sis demonstrated that vitamin A supplementation was not an independent risk factor for death or BPD. ●Vitamin Amay be beneficial in a subset of preterm infants, as suggested by a post-hoc subgroup analysis of data from the largest placebo-controlled trial [9]. In this report, the benefit of vitamin A therapy was greater for infants at a lower risk for BPD than those at a higher risk. However, as noted by the authors, data used for this study was from 1996 to 1997 and other aspects of clinical care have changed, which may have impacted these results.
|
17_0
|
bronchopulmonary-dysplasia-bpd-prevention - INTERVENTIONS - Breast milk
|
Mother's own milk is the preferred form of nutrition for preterm infants as it offers several advantages over formula, including prevention of BPD. (See Mother's own milk is the preferred form of nutrition for preterm infants as it offers several advantages over formula, including prevention of BPD. (See "Human milk feeding and fortification of human milk for premature infants", section on 'Benefits of mother's milk' .)
|
17_1
|
bronchopulmonary-dysplasia-bpd-prevention - INTERVENTIONS - Breast milk
|
ng and fortification of human milk for premature infants", section on 'Benefits of mother's milk' .) A meta-analysis of 17 cohort studies and 5 RCTs (8661 neonates) demonstrated that human milk compared with formula is associated with a lower incidence of BPD, although the certainty of this finding is low [10]. In addition, an observational study found breast milk from the mother reduced the risk of BPD and reported a dose-response relationship with an increased reduction in BPD as the volume of consumed breast milk increased [11]. However, the results of this study are limited by the potential of confounding factors.
|
18_0
|
bronchopulmonary-dysplasia-bpd-prevention - INTERVENTIONS - Unproven interventions
|
Interventions that are ineffective in preventing BPD include sustained inflation in the delivery room for infants requiring respiratory support, Interventions that are ineffective in preventing BPD include sustained inflation in the delivery room for infants requiring respiratory support, inhaled nitric oxide alone or in combination with surfactant, bronchodilators, and supplementation with docosahexaenoic acid. ●Sustained inflation in the delivery room– Sustained lung inflation during neonatal resuscitation in the delivery room may be harmful and should beavoided, as discussed separately.
|
18_1
|
bronchopulmonary-dysplasia-bpd-prevention - INTERVENTIONS - Unproven interventions
|
tal resuscitation in the delivery room may be harmful and should beavoided, as discussed separately. (See"Neonatal resuscitation in the delivery room", section on 'Sustained inflation'.) ●Inhaled nitric oxide(iNO)– The available data do not support the use of iNO (either alone or in combination with surfactant) as an intervention to prevent BPD. We agree with the guidance of the expert panel convened by the National Institute of Health and a 2014 American Academy of Pediatrics clinical report that recommendagainstthe use of iNO in the routine management of preterm infants below 34 weeks gestation who require respiratory support [12,13].
|
18_2
|
bronchopulmonary-dysplasia-bpd-prevention - INTERVENTIONS - Unproven interventions
|
tine management of preterm infants below 34 weeks gestation who require respiratory support [12,13]. Data on the use of iNO in the management of preterm neonates with RDS are discussed separately. (See"Respiratory distress syndrome (RDS) in preterm neonates: Management", section on 'Limited role for inhaled nitric oxide'.) However, iNO is a well-established treatment for term or late preterm infants with persistent pulmonary hypertension, as discussed separately. (See"Persistent pulmonary hypertension of the newborn (PPHN): Management and outcome", section on 'Inhaled nitric oxide (iNO)'.)
|
18_3
|
bronchopulmonary-dysplasia-bpd-prevention - INTERVENTIONS - Unproven interventions
|
pertension of the newborn (PPHN): Management and outcome", section on 'Inhaled nitric oxide (iNO)'.) ●Late surfactant therapy– Late deficiency of postnatal surfactant production or surfactant dysfunction has been proposed as a contributor for the pathogenesis of BPD because it may be associated with episodes of respiratory deterioration in ventilator-dependent preterm infants. However, late administration of surfactant does not appear to reduce the risk of BPD, as discussed separately. (See"Respiratory distress syndrome (RDS) in preterm neonates: Management", section on 'Timing'.) ●Combination of steroid and surfactant– Data on the use of combination surfactant plusbudesonideare limited.
|
18_4
|
bronchopulmonary-dysplasia-bpd-prevention - INTERVENTIONS - Unproven interventions
|
tion of steroid and surfactant– Data on the use of combination surfactant plusbudesonideare limited. This therapy cannot be recommended until there are more definitive data establishing its safety and efficacy. The data supporting this intervention are discussed separately. (See"Postnatal use of glucocorticoids for prevention of bronchopulmonary dysplasia (BPD) in preterm infants", section on 'No role for intratracheal glucocorticoids mixed with surfactant'.) ●Bronchodilators– Data on the use of bronchodilators are limited. In a systematic review, only one randomized trial had usable outcome data.
|
18_5
|
bronchopulmonary-dysplasia-bpd-prevention - INTERVENTIONS - Unproven interventions
|
nchodilators are limited. In a systematic review, only one randomized trial had usable outcome data. In this trial of 173 preterm infants (gestational age less than 31 weeks), salbutamol did not reduce the risk of BPD at 28 days when compared to no intervention/placebo (RR 1.03, 95% CI 0.78-1.37) [14]. ●Long-chain fatty acids– Docosahexaenoic acid (DHA) and other omega-3 long-chain polyunsaturated fatty acids (LCPUFAs) are integral components of the brain and retinal phospholipid membrane. Preterm infants miss some of the fetal accretion of DHA, which normally occurs during the third trimester of pregnancy.
|
18_6
|
bronchopulmonary-dysplasia-bpd-prevention - INTERVENTIONS - Unproven interventions
|
s some of the fetal accretion of DHA, which normally occurs during the third trimester of pregnancy. Based upon the available evidence, direct or indirect LCPUFA supplementation does not appear to prevent BPD. However, LCPUFA supplementation appears to have other beneficial effects in preterm infants, particularly on neurocognitive and visual development. Recommendations regarding maternal and infant LCPUFA supplementation are provided separately. (See"Enteral long-chain polyunsaturated fatty acids (LCPUFA) for preterm and term infants".)
|
18_7
|
bronchopulmonary-dysplasia-bpd-prevention - INTERVENTIONS - Unproven interventions
|
rately. (See"Enteral long-chain polyunsaturated fatty acids (LCPUFA) for preterm and term infants".) ●Superoxide dismutase– Superoxide dismutase is a naturally occurring enzyme that provides defense against oxidative injury, which has been implicated in the pathogenesis of BPD. In the available clinical trials, postnatal administration of superoxide dismutase did not have any apparent benefit in terms of reducing the incidence of BPD, other morbidities, or mortality [15]. Superoxide dismutase is not available for clinical use, and it remains an investigational drug. ●Pentoxifylline–Pentoxifyllineis a xanthine derivative with anti-inflammatory properties.
|
18_8
|
bronchopulmonary-dysplasia-bpd-prevention - INTERVENTIONS - Unproven interventions
|
onal drug. ●Pentoxifylline–Pentoxifyllineis a xanthine derivative with anti-inflammatory properties. The use of nebulized pentoxifylline as a preventive measure for BPD was studied in a single small pilot randomized trial [16,17]. As such, additional data are needed before pentoxifylline can be recommended as a routine measure to prevent or treat BPD in neonates. Studies investigating the use of pentoxifylline in the treatment of neonatal sepsis are discussed elsewhere.
|
18_9
|
bronchopulmonary-dysplasia-bpd-prevention - INTERVENTIONS - Unproven interventions
|
investigating the use of pentoxifylline in the treatment of neonatal sepsis are discussed elsewhere. (See"Neonatal bacterial sepsis: Treatment, prevention, and outcome in neonates <35 weeks gestation", section on 'Therapies with uncertain benefit'and"Neonatal bacterial sepsis: Treatment, prevention, and outcome in neonates ≥35 weeks gestation".)
|
19_0
|
bronchopulmonary-dysplasia-bpd-prevention - SOCIETY GUIDELINE LINKS
|
Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See"Society guideline links: Bronchopulmonary dysplasia".)
|
20_0
|
bronchopulmonary-dysplasia-bpd-prevention - INFORMATION FOR PATIENTS
|
UpToDate offers two types of patient education materials, "The Basics" and "Beyond the Basics." The Basics patient education pieces are written in plain language, at the 5thto 6thgrade reading level, and they answer the four or five key questions a patient might have about a given condition. These articles are best for patients who want a general overview and who prefer short, easy-to-read materials. Beyond the Basics patient education pieces are longer, more sophisticated, and more detailed.
|
20_1
|
bronchopulmonary-dysplasia-bpd-prevention - INFORMATION FOR PATIENTS
|
rials. Beyond the Basics patient education pieces are longer, more sophisticated, and more detailed. These articles are written at the 10thto 12thgrade reading level and are best for patients who want in-depth information and are comfortable with some medical jargon. Here are the patient education articles that are relevant to this topic. We encourage you to print or e-mail these topics to your patients. (You can also locate patient education articles on a variety of subjects by searching on "patient info" and the keyword(s) of interest.) ●Basics topics (see"Patient education: Bronchopulmonary dysplasia (The Basics)")
|
21_0
|
bronchopulmonary-dysplasia-bpd-prevention - SUMMARY AND RECOMMENDATIONS
|
●Definition– Clinically, BPD is defined as an ongoing need for supplemental oxygen and/or respiratory support at either 28 days postnatal age or 36 weeks postmenstrual age (calculator 1) in a preterm neonate with radiographic evidence of parenchymal lung disease (image 1). Various criteria are used to define BPD (table 2). (See'Terminology'above.)
|
21_1
|
bronchopulmonary-dysplasia-bpd-prevention - SUMMARY AND RECOMMENDATIONS
|
ung disease (image 1). Various criteria are used to define BPD (table 2). (See'Terminology'above.) ●Effective interventions– Interventions that are effective for reducing the risk of bronchopulmonary dysplasia (BPD) in extremely preterm (EPT) infants (gestational age [GA] <28 weeks) who are at risk for BPD include (algorithm 1) (see'Our approach'above and'Interventions'above): •Antenatal glucocorticoid therapy– Antenatal glucocorticoid therapy for pregnant individuals <34 weeks gestation who are at high risk for preterm delivery, which is discussed in detail separately.
|
21_2
|
bronchopulmonary-dysplasia-bpd-prevention - SUMMARY AND RECOMMENDATIONS
|
weeks gestation who are at high risk for preterm delivery, which is discussed in detail separately. (See"Antenatal corticosteroid therapy for reduction of neonatal respiratory morbidity and mortality from preterm delivery".) •Nutrition and fluid management– In all preterm infants, nutritional goals are set to provide adequate caloric intake to promote somatic and lung growth, and fluid intake is adjusted to maintain neutral or slightly negative water balance. Mother's breast milk is the preferred nutritional source, and if not available, donor breast milk is used. These issues are discussed separately.
|
21_3
|
bronchopulmonary-dysplasia-bpd-prevention - SUMMARY AND RECOMMENDATIONS
|
onal source, and if not available, donor breast milk is used. These issues are discussed separately. (See"Approach to enteral nutrition in the premature infant"and"Parenteral nutrition in premature infants"and"Fluid and electrolyte therapy in newborns"and"Human milk feeding and fortification of human milk for premature infants"and"Respiratory distress syndrome (RDS) in preterm neonates: Management", section on 'Fluid management'.) •Oxygen targets– In preterm infants who require supplemental oxygen, target oxygen saturation (SpO2) levels are set for values between 90 and 95 percent, as discussed separately.
|
21_4
|
bronchopulmonary-dysplasia-bpd-prevention - SUMMARY AND RECOMMENDATIONS
|
ygen saturation (SpO2) levels are set for values between 90 and 95 percent, as discussed separately. (See"Neonatal target oxygen levels for preterm infants", section on 'Oxygen target levels'.) •Ventilation strategies that minimize lung injury– Use of ventilation strategies that minimize lung injury, including preferential use of noninvasive modalities. The approach to mechanical ventilation in preterm infants is summarized in the table (table 3) and discussed in detail separately. (See"Respiratory distress syndrome (RDS) in preterm neonates: Management", section on 'Clinical approach'and"Approach to mechanical ventilation in very preterm neonates".)
|
21_5
|
bronchopulmonary-dysplasia-bpd-prevention - SUMMARY AND RECOMMENDATIONS
|
t", section on 'Clinical approach'and"Approach to mechanical ventilation in very preterm neonates".) •Caffeinetherapy– Earlycaffeinetherapy is routinely given to all EPT infants, as discussed separately. (See"Management of apnea of prematurity", section on 'Caffeine'.) •Vitamin Asupplementation– The use ofvitamin Asupplementation is center-dependent. If vitamin A is available, practitioners may consider its administration to EPT infants who require ventilatory support; however, the relative benefit of vitamin A supplementation in this setting appears to be small. (See'Vitamin A'above.)
|
21_6
|
bronchopulmonary-dysplasia-bpd-prevention - SUMMARY AND RECOMMENDATIONS
|
ive benefit of vitamin A supplementation in this setting appears to be small. (See'Vitamin A'above.) •Postnatal glucocorticoids– We donotroutinely administer postnatal systemic or inhaled glucocorticoids to prevent BPD. Systemic glucocorticoids are reserved for EPT infants who remain ventilator-dependent and/or require oxygen supplementation >50 percent at a postnatal age of two to four weeks. This is discussed in detail separately. (See"Postnatal use of glucocorticoids for prevention of bronchopulmonary dysplasia (BPD) in preterm infants".)
|
21_7
|
bronchopulmonary-dysplasia-bpd-prevention - SUMMARY AND RECOMMENDATIONS
|
atal use of glucocorticoids for prevention of bronchopulmonary dysplasia (BPD) in preterm infants".) ●Ineffective interventions– Interventions that do not appear to be effective for prevention of BPD in EPT infants include (see'Unproven interventions'above): •Sustained lung inflation during neonatal resuscitation (see"Neonatal resuscitation in the delivery room", section on 'Sustained inflation') •Inhaled nitric oxide (iNO) (see"Respiratory distress syndrome (RDS) in preterm neonates: Management", section on 'Limited role for inhaled nitric oxide') •Late surfactant therapy (see"Respiratory distress syndrome (RDS) in preterm neonates: Management", section on 'Timing')
|
22_0
|
bronchopulmonary-dysplasia-bpd-prevention - ACKNOWLEDGMENT
|
The editorial staff at UpToDate acknowledge James Adams, Jr., MD, who contributed to an earlier version of this topic review.
|
24_0
|
bronchopulmonary-sequestration - SUMMARY AND RECOMMENDATIONS
|
●Definition and types– Bronchopulmonary sequestration (BPS) is a rare congenital abnormality of the lower respiratory tract. It consists of a nonfunctioning mass of lung tissue that lacks normal communication with the tracheobronchial tree and receives its arterial blood supply from the systemic circulation. The connections to the tracheobronchial tree and systemic artery distinguishes BPS from congenital pulmonary airway malformation (CPAM). (See'Anatomic characteristics'above.) •An intralobar sequestration (ILS) is located within a normal lobe and lacks its own visceral pleura.
|
24_1
|
bronchopulmonary-sequestration - SUMMARY AND RECOMMENDATIONS
|
An intralobar sequestration (ILS) is located within a normal lobe and lacks its own visceral pleura. This type often has aberrant connections to bronchi, lung parenchyma, or the gastrointestinal tract and often presents with recurrent infections. •An extralobar sequestration (ELS) is located outside the normal lung and has its own visceral pleura. Infectious complications are rare, except in ELS with connections to the gastrointestinal tract or intrapulmonary structures, which is unusual.
|
24_2
|
bronchopulmonary-sequestration - SUMMARY AND RECOMMENDATIONS
|
n ELS with connections to the gastrointestinal tract or intrapulmonary structures, which is unusual. ●Associated anomalies– Congenital abnormalities that are sometimes associated with BPS include congenital diaphragmatic hernia, vertebral anomalies, congenital heart disease, pulmonary hypoplasia, colonic duplication, and CPAM. These associated anomalies are more common in ELS compared with ILS. (See'Associated anomalies'above.) ●Clinical presentation– The clinical presentation of BPS is variable and depends on the type, size, and location of the lesion.
|
24_3
|
bronchopulmonary-sequestration - SUMMARY AND RECOMMENDATIONS
|
clinical presentation of BPS is variable and depends on the type, size, and location of the lesion. Many cases are initially detected by prenatal ultrasound; most of these regress during gestation, while others progress and hydrops may develop. The affected newborn is usually asymptomatic but sometimes presents with respiratory distress. Some cases (usually ILS) present with recurrent pneumonia during infancy or childhood. (See'Clinical presentation'above.) ●Postnatal evaluation– All cases of BPS or other congenital abnormalities of the lower airway should be further evaluated with postnatal imaging.
|
24_4
|
bronchopulmonary-sequestration - SUMMARY AND RECOMMENDATIONS
|
her congenital abnormalities of the lower airway should be further evaluated with postnatal imaging. This includes cases that regressed or appeared to resolve in utero because few lesions resolve completely and advanced imaging is more sensitive than prenatal ultrasound for detecting small lesions. (See'Postnatal imaging'above.) •After birth, the first step is a plain chest radiograph. On a chest radiograph, sequestrations typically appear as a uniformly dense mass within the thoracic cavity or pulmonary parenchyma (image 4). Recurrent infection can lead to cystic areas within the mass, and there may be air-fluid levels if the lesion communicates with a bronchus.
|
24_5
|
bronchopulmonary-sequestration - SUMMARY AND RECOMMENDATIONS
|
areas within the mass, and there may be air-fluid levels if the lesion communicates with a bronchus. •The second step is advanced thoracic imaging, the timing of which depends on the patient's characteristics, as outlined in the algorithm (algorithm 1). This is to confirm the diagnosis, including identifying the aberrant artery that distinguishes BPS, and to help with surgical planning. ●Management •Symptomatic– Infants with BPS that is causing any respiratory symptoms (respiratory distress or tachypnea) are treated with surgical excision; surgery is curative and is associated with minimal morbidity. The procedure is performed urgently in newborns with significant respiratory distress.
|
24_6
|
bronchopulmonary-sequestration - SUMMARY AND RECOMMENDATIONS
|
al morbidity. The procedure is performed urgently in newborns with significant respiratory distress. Surgical resection is typically performed electively in older children who present with infection. (See'Symptomatic patients'above.) •Asymptomatic,high risk– For asymptomatic patients of any age with characteristics that suggest a high risk for developing complications (large lesions occupying >20 percent of the hemithorax, bilateral or multifocal cysts, pneumothorax, or a family history of pleuropulmonary blastoma-associated conditions (table 1)), we suggest surgical resection rather than observation (Grade 2C). (See'High risk'above.)
|
24_7
|
bronchopulmonary-sequestration - SUMMARY AND RECOMMENDATIONS
|
(table 1)), we suggest surgical resection rather than observation (Grade 2C). (See'High risk'above.) •Asymptomatic, low risk– For asymptomatic patients without these high-risk characteristics, either elective surgical resection or conservative management with observation are reasonable options and practice varies (algorithm 1). (See'Low risk'above.) -In our practice, we generally perform surgery for all asymptomatic infants with BPS, regardless of the lesion's size and characteristics. The surgery is elective and is usually performed between 6 and 12 months of age.
|
24_8
|
bronchopulmonary-sequestration - SUMMARY AND RECOMMENDATIONS
|
nd characteristics. The surgery is elective and is usually performed between 6 and 12 months of age. Our preference for surgery is based on the good outcomes after surgery and on the risk of developing complications (primarily infection) if surgery is not performed. The likelihood and risk factors for developing complications if surgery is not performed are poorly delineated. (See'Outcome'above.) -Other authors prefer to observe asymptomatic patients, especially if the lesion is small, noncystic, and appears to be consistent with ELS. Optimal surveillance strategies for observation have not been determined.
|
25_0
|
bronchopulmonary-sequestration - INTRODUCTION
|
Bronchopulmonary sequestration (BPS), sometimes referred to simply as pulmonary sequestration, is a rare congenital abnormality of the lower airway. It consists of a nonfunctioning mass of lung tissue that lacks normal communication with the tracheobronchial tree and that receives its arterial blood supply from the systemic circulation [1]. BPS can present in several ways. Extralobar BPS is often identified on prenatal ultrasound and becomes symptomatic early in life, whereas intralobar BPS is more commonly identified later in life secondary to recurrent infection.
|
25_1
|
bronchopulmonary-sequestration - INTRODUCTION
|
, whereas intralobar BPS is more commonly identified later in life secondary to recurrent infection. The postnatal presentation and management of BPS will be discussed below. Prenatal manifestations and management are described in a separate topic review. (See"Bronchopulmonary sequestration: Prenatal diagnosis and management".)
|
26_0
|
bronchopulmonary-sequestration - DEFINITIONS
|
BPS is a nonfunctioning mass of lung tissue, with airway and alveolar elements, that lacks normal communication with the tracheobronchial tree and receives its arterial blood supply from the systemic circulation. The subtypes are classified anatomically, as follows: ●Intralobar sequestration (ILS)– An ILS (also known as intrapulmonary sequestration) is located within a normal lobe and lacks its own visceral pleura. ILS accounts for approximately 75 percent of BPS.
|
26_1
|
bronchopulmonary-sequestration - DEFINITIONS
|
n a normal lobe and lacks its own visceral pleura. ILS accounts for approximately 75 percent of BPS. ●Extralobar sequestration (ELS)– An ELS (also known as extrapulmonary sequestration) is located outside the normal lung and has its own visceral pleura. Occasionally, it is located below the diaphragm [2]. ELS accounts for approximately 25 percent of BPS and is more likely to be associated with other congenital anomalies. ●Hybrid BPS/congenital pulmonary airway malformation (CPAM) lesions– In a hybrid lesion, BPS (either ILS or ELS) occurs in combination with a CPAM.
|
26_2
|
bronchopulmonary-sequestration - DEFINITIONS
|
ation (CPAM) lesions– In a hybrid lesion, BPS (either ILS or ELS) occurs in combination with a CPAM. These hybrid lesions have histologic features of CPAM, have a blood supply from a systemic artery, and have been reported in a substantial proportion of cases of BPS [3,4]. (See"Congenital pulmonary airway malformation".) ●Bronchopulmonary foregut malformation– This term is usually used to refer to a rare variant of sequestration in which the sequestered lung tissue is connected to the gastrointestinal tract [5]. This may occur in either ILS or ELS. Occasionally, bronchopulmonary foregut malformation is used as a general term to include all foregut malformations.
|
27_0
|
bronchopulmonary-sequestration - EPIDEMIOLOGY
|
Congenital abnormalities of the lower respiratory tract are rare, found in approximately 1 in 10,000 to 35,000 live births [4]. Among these, the most common is congenital pulmonary airway malformation (CPAM), while BPS represents only 0.15 to 6.40 percent [6]. In several reports, even tertiary care referral centers diagnose less than one case per year of BPS [7-10]. Intralobar sequestration (ILS) is overall the most common form, comprising approximately 75 to 90 percent of sequestrations, while 10 to 25 percent are extralobar sequestration (ELS) [6,11].
|
27_1
|
bronchopulmonary-sequestration - EPIDEMIOLOGY
|
5 to 90 percent of sequestrations, while 10 to 25 percent are extralobar sequestration (ELS) [6,11]. The difference in prevalence of the disorders may be related to the pathogenic mechanisms, as discussed below. Males and females are equally affected with ILS, while ELS has a male predominance in most [1,10], but not all [3], reports. In a series of ELS cases diagnosed antenatally, the ratio of males to females was three to one [12,13]. In contrast, bronchopulmonary foregut malformation has a female predominance [5].
|
28_0
|
bronchopulmonary-sequestration - PATHOGENESIS
|
The embryologic basis for the development of BPS and other congenital abnormalities of the lower airway are not fully understood [5,14]. The most widely accepted embryologic theory is that BPS originates early in the pseudoglandular stage of lung development (5 to 17 weeks of gestation), prior to separation of the aortic and pulmonary circulations [15].
|
28_1
|
bronchopulmonary-sequestration - PATHOGENESIS
|
ent (5 to 17 weeks of gestation), prior to separation of the aortic and pulmonary circulations [15]. This would explain the wide spectrum of pathology observed, including the connections to the systemic circulation, the presence of separate visceral pleura in extralobar sequestration (ELS) or lack thereof in intralobar sequestration (ILS), the occurrence of hybrid lesions with features of BPS and congenital pulmonary airway malformation (CPAM), and the occasional associations with bronchogenic cysts or connections to the foregut, as well as associated anomalies such as congenital diaphragmatic hernia [15-17]. In utero airway obstruction may contribute to some of the morphologic changes [18].
|
28_2
|
bronchopulmonary-sequestration - PATHOGENESIS
|
hernia [15-17]. In utero airway obstruction may contribute to some of the morphologic changes [18]. Another proposed explanation is that a portion of the developing lung is mechanically separated from the rest of the organ by compression from vascular structures, traction by aberrant systemic vessels, or inadequate pulmonary blood flow. However, this mechanical hypothesis does not completely explain all types of lesions, specifically bronchopulmonary foregut malformation [5,14]. In the past, ILS was proposed to be an acquired rather than a developmental lesion.
|
28_3
|
bronchopulmonary-sequestration - PATHOGENESIS
|
ormation [5,14]. In the past, ILS was proposed to be an acquired rather than a developmental lesion. This hypothesis was suggested by the late presentations of ILS in historical series and also by observations that systemic arterial collaterals (resembling BPS) occasionally develop in the setting of pulmonary inflammatory processes [19,20].
|
29_0
|
bronchopulmonary-sequestration - ANATOMIC CHARACTERISTICS
|
Sequestrations are characterized by their location, connection to pulmonary or other structures, vascular supply, and association with other abnormalities. By definition, their arterial blood supply is from the systemic circulation.
|
30_0
|
bronchopulmonary-sequestration - ANATOMIC CHARACTERISTICS - Intralobar sequestration
|
Intralobar sequestrations (ILS) are located within a normal lobe and lack their own visceral pleura. Most ILS occur in the lower lobes, but they can occur anywhere within the thorax [ Intralobar sequestrations (ILS) are located within a normal lobe and lack their own visceral pleura. Most ILS occur in the lower lobes, but they can occur anywhere within the thorax [ 21 ].
|
30_1
|
bronchopulmonary-sequestration - ANATOMIC CHARACTERISTICS - Intralobar sequestration
|
ral pleura. Most ILS occur in the lower lobes, but they can occur anywhere within the thorax [ 21 ]. Approximately 60 percent are located in the posterior basal segment of the left lower lobe [ 1,5,8,11,22 ], and rare instances of bilateral ILS (or ILS with contralateral extralobar sequestration [ELS]) have been reported [ 23 ]. They generally have no bronchial connection to the proximal airway. If a connection exists, it is abnormal. However, anomalous connections can link the sequestration to other bronchi, or lung parenchyma, and there are connections to the gastrointestinal tract in approximately 10 percent, constituting a bronchopulmonary foregut malformation [ 11,15 ].
|
30_2
|
bronchopulmonary-sequestration - ANATOMIC CHARACTERISTICS - Intralobar sequestration
|
l tract in approximately 10 percent, constituting a bronchopulmonary foregut malformation [ 11,15 ]. These connections and/or the pores of Kohn may allow bacteria to enter the sequestration and cause recurrent infection, a common finding in ILS ( picture 1 ). The arterial supply usually is derived from the lower thoracic or upper abdominal aorta. In a series of 25 cases, 16 had a single arterial trunk and the remainder had multiple arterial vessels (image 1A-B) [24]. Venous drainage is usually normal to the left atrium, although abnormal connections to the vena cava, azygous vein, or right atrium may occur [11].
|
30_3
|
bronchopulmonary-sequestration - ANATOMIC CHARACTERISTICS - Intralobar sequestration
|
trium, although abnormal connections to the vena cava, azygous vein, or right atrium may occur [11]. On pathologic examination, there are often changes at the pleural surface overlying the abnormal region [25]. On cut section, the parenchyma of the sequestration is usually sharply demarcated from the adjacent normal tissue. The abnormal parenchyma has enlarged airspaces and thickening of the airspace wall (picture 1). The airways of the lesion are dilated and filled with mucus, with regions of inflammation, mucus accumulation, and microcystic changes, with more distortion of the lung parenchyma than is typically seen in ELS.
|
30_4
|
bronchopulmonary-sequestration - ANATOMIC CHARACTERISTICS - Intralobar sequestration
|
and microcystic changes, with more distortion of the lung parenchyma than is typically seen in ELS. Sometimes, dilated lymphatic channels are associated with the lesion (picture 2). (See"Congenital anomalies of the intrathoracic airways and tracheoesophageal fistula".)
|
31_0
|
bronchopulmonary-sequestration - ANATOMIC CHARACTERISTICS - Extralobar sequestration
|
Extralobar sequestrations (ELS) are located outside the normal lung and have their own visceral pleura, with a pedicle that contains the vascular connections. They vary in size but usually are relatively small compared with the normal lobes. The vast majority are in the left hemithorax, and the most common location is between the left lower lobe and hemidiaphragm (80 percent) [ Extralobar sequestrations (ELS) are located outside the normal lung and have their own visceral pleura, with a pedicle that contains the vascular connections.
|
31_1
|
bronchopulmonary-sequestration - ANATOMIC CHARACTERISTICS - Extralobar sequestration
|
rmal lung and have their own visceral pleura, with a pedicle that contains the vascular connections. They vary in size but usually are relatively small compared with the normal lobes. The vast majority are in the left hemithorax, and the most common location is between the left lower lobe and hemidiaphragm (80 percent) [ 26,27 ]. Occasionally, ELS may present within or below the diaphragm or in the retroperitoneum, particularly in the region of the adrenal gland where they may mimic a suprarenal neuroblastoma [ 28 ]. Like ILS, ELS lesions lack a bronchial connection to the normal proximal airway. They may connect to the gastrointestinal tract or, rarely, to intrapulmonary structures [ 11 ].
|
31_2
|
bronchopulmonary-sequestration - ANATOMIC CHARACTERISTICS - Extralobar sequestration
|
way. They may connect to the gastrointestinal tract or, rarely, to intrapulmonary structures [ 11 ]. Because intrapulmonary connections are uncommon in ELS, infectious complications are also uncommon. The arterial supply of ELS usually comes from an aberrant vessel arising from the thoracic aorta [ 11 ]. The vessel is usually small, with low flow. Lesions typically have anomalous venous drainage to the right atrium, vena cava, or azygous systems [ 29 ]. On histologic examination, ELS may resemble normal lung or show parenchymal maldevelopment similar to the small-cyst type of congenital pulmonary airway malformation (CPAM) [ 25 ].
|
32_0
|
bronchopulmonary-sequestration - ANATOMIC CHARACTERISTICS - Hybrid BPS/CPAM lesions
|
Hybrid lesions, with features of BPS and CPAM, occur in a substantial proportion of BPS [ Hybrid lesions, with features of BPS and CPAM, occur in a substantial proportion of BPS [ 3,30,31 ] and comprise 15 to 40 percent of all cystic lung lesions [ 32 ]. These lesions have blood supply from a systemic artery consistent with BPS, but they also have histologic features of CPAM. In one report, five cases of ILS and one of ELS that were diagnosed prenatally had a systemic artery detected at surgical resection, but histology was consistent with CPAM [ 30 ].
|
32_1
|
bronchopulmonary-sequestration - ANATOMIC CHARACTERISTICS - Hybrid BPS/CPAM lesions
|
had a systemic artery detected at surgical resection, but histology was consistent with CPAM [ 30 ]. In another series, 23 of 46 cases of ELS had histologic features of CPAM type 2 [ 3 ]. Of these, 11 had rhabdomyomatous degeneration.
|
End of preview. Expand
in Data Studio
README.md exists but content is empty.
- Downloads last month
- -