Risk factors for pneumothorax in very low birth weight infants

Association between mean airway pressure during high-frequency oscillatory ventilation and pulmonary air leak in extremely preterm infants during the first week of life

Background

While positive pressure ventilation has been considered an important contributing factor associated with pulmonary air leaks, studies examining the association between specific ventilatory settings during acute-phase high-frequency oscillatory ventilation (HFOV) and pulmonary air leaks among extremely preterm infants are limited.

Methods

This was a single-center retrospective cohort study conducted at an institution that primarily used HFOV after intubation in extremely preterm infants. We analyzed data from extremely preterm infants born between 2010 and 2021. The primary outcome was pulmonary air leakage during the first 7 days of life. The exposure variable was the maximum mean airway pressure (MAP) on HFOV during the first 7 days of life or before the onset of pulmonary air leaks. Maximum MAP was categorized into three groups: low (7-10 cmH2O), moderate (11-12 cmH2O), and high (13-15 cmH2O) MAP categories. We conducted robust Poisson regression analyses after adjustment for perinatal confounders, using the low MAP category as the reference.

Results

The cohort included 171 infants (low MAP, 123; moderate MAP, 27; and high MAP, 21). The median (interquartile range) gestational age and birth weight were 25.7 (24.3-26.7), 25.7 (24.9-26.9), and 25.3 (24.3-26.6) weeks and 760 (612-878), 756 (648-962), and 734 (578-922) g for infants in the low, moderate, and high MAP categories, respectively. Compared to infants in the low MAP category, those in the high MAP category had a higher incidence of pulmonary air leaks (4.1% vs. 33.3%; adjusted risk ratio, 5.4; 95% confidence interval, 1.6-18.5). In contrast, there was no clear difference in the risk of pulmonary air leaks between the moderate and low MAP categories (3.7% vs. 4.1%; adjusted risk ratio, 0.9; 95% confidence interval, 0.1-6.1).

Conclusion

Extremely preterm infants requiring high MAP (≥13 cmH2O) in acute-phase HFOV had a higher risk of pulmonary air leak during the first 7 days of life.

Risk Factors for Pneumothorax and Its Association with Ventilation in Neonates

OBJECTIVE

 The mode of ventilation that is implicated in pneumothorax is the one at the time of its diagnosis. Although there is evidence that air leak starts many hours before it is clinically evident, there are no prior studies that have investigated the association of pneumothorax with the mode of ventilation few hours before rather than at the time of its diagnosis.

STUDY DESIGN

 A retrospective case-control study was conducted in the neonatal intensive care unit (NICU) between 2006 and 2016 where cases of neonates with pneumothorax were compared with gestational age-matched control neonates without pneumothorax. Respiratory support associated with pneumothorax was classified as the mode of ventilation 6 hours before the clinical diagnosis of pneumothorax. We investigated the factors that were different between cases and controls, and between cases of pneumothorax on bubble continuous positive airway pressure (bCPAP) and invasive mechanical ventilation (IMV).

RESULT

 Of the 8,029 neonates admitted in the NICU during the study period, 223 (2.8%) developed pneumothorax. Among these, 127 occurred among 2,980 (4.3%) neonates on bCPAP, 38 among 809 (4.7%) neonates on IMV, and the remaining 58 among 4,240 (1.3%) neonates on room air. Those with pneumothorax were more likely to be male, have higher body weight, require respiratory support and surfactant administration, and have bronchopulmonary dysplasia (BPD). Among those who developed pneumothorax, there were differences in the gestational age, gender, and use of antenatal steroids between those who were on bCPAP as compared to those on IMV. IMV was associated with increased odds of pneumothorax as compared to those on bCPAP in a multivariable regression analysis. Cases on IMV had higher incidence of intraventricular hemorrhage, retinopathy of prematurity, BPD, and necrotizing enterocolitis, as well as longer length of stay as compared to those on bCPAP.

CONCLUSION

 Neonates who require any respiratory support have higher incidence of pneumothorax. Among those on respiratory support, those on IMV had higher odds of pneumothorax and worse clinical outcomes as compared to those on bCPAP.

KEY POINTS

· The process of air leak leading to pneumothorax in majority of neonates starts much before it is clinically diagnosed.. · It is possible to detect the air leak early in the process by subtle changes in the signs, symptoms and changes in lung function.. · True association of the ventilation associated with pneumothorax is not at the time of diagnosis of pneumothorax but few hours before it is diagnosed.. · There is higher incidence of pneumothorax in neonates on any respiratory support.. · There is significantly higher incidence of pneumothorax among neonates on invasive ventilations as compared to noninvasive ventilation after correction for all other clinical factors..

Use of Fibrin Glue in the Treatment of Persistent Pneumothorax in Premature Infants at the Limit of Viability: Ethical Issues and Two and A Half Years Follow-Up

INTRODUCTION

Due to the extreme immaturity of many internal organs, including lungs, infants at the limit of viability are more predisposed to a pneumothorax (PTX). In some cases, PTX becomes persistent. Previously, only a few attempts of PTX treatment with fibrin glue were reported. However, its impact on further lung development is unknown.

CASE REPORT

We present a case of an extremely preterm infant with persistent PTX who was successfully treated with fibrin glue. In addition, we present a two-and-a-half-year corrected age follow-up focusing on respiratory problems, motor development and sensory organs. Furthermore, we touch upon the related ethical issues.

CONCLUSIONS

Fibrin glue should be used to treat persistent PTX even in an extremely preterm infant. No adverse effects were observed. At the two-and-a-half-year corrected age follow-up, despite severe bronchopulmonary dysplasia development, no serious pulmonary problems were observed. However, the child's development is uncertain. This situation raises important ethical issues concerning saving the lives of infants at the limit of viability.

Clinical Profile and Outcome of Neonatal Pneumothorax: Seven Years of Experience in a Tertiary Care Center

BACKGROUND

Neonatal pneumothorax (NP) in neonates is a medical emergency with a significant incidence of morbidity and mortality. There is a paucity of national and regional data about the epidemiological and clinical profiles of pneumothorax.

AIM

The study aim is to identify the demographics, predisposing factors, clinical profiles, and outcomes of NP in a tertiary neonatal care center in Saudi Arabia.

METHODS

A retrospective study of all newborns admitted at the neonatal intensive care unit at International Medical Centre, Jeddah, Saudi Arabia, over seven years period between January 2014 and December 2020 was reviewed. A total of 3,629 newborns admitted to the neonatal intensive care unit were included in the study. Data collected included baseline characteristics, predisposing factors, associated morbidities, management, and outcomes of NP. Data were analyzed using the Statistical Package for Social Sciences (SPSS) version 26 (IBM Corp., Armonk, NY).

RESULTS

Of a total of 3,692 included neonates, pneumothorax was detected in 32 neonates with an incidence of 1.02% (ranging from 0.69% to 2%), and 53.1% were males. The mean gestational age was 32 weeks. Our study found that most infants with pneumothorax were extremely low birth weight (ELBW) in 19 babies (59%). The most common predisposing factors were respiratory distress syndrome in 31 babies (96.9%) followed by the need for bag-mask ventilation in 26 babies (81.3%). Twelve newborns (37.5%) with pneumothorax died. Following an analysis of all risk variables, the one-minute Apgar score <5, associated intraventricular hemorrhage, and respiratory support need were shown to be significantly linked with death.

CONCLUSION

 Pneumothorax is not an uncommon neonatal emergency event, especially for ELBW infants, infants requiring respiratory support, or infants with underlying lung disease. Our study describes the clinical profile and affirms the significant burden of NP.

Association between ventilatory settings and pneumothorax in extremely preterm neonates

OBJECTIVES

Pneumothorax is a catastrophic event associated with high morbidity and mortality, and it is relatively common in neonates. This study aimed to investigate the association between ventilatory parameters and the risk of developing pneumothorax in extremely low birth weight neonates.

METHODS

This single-center retrospective cohort study analyzed 257 extremely low birth weight neonates admitted to a neonatal intensive care unit between January 2012 and December 2017. A comparison was carried out to evaluate the highest value of positive end-expiratory pressure (PEEP), peak inspiratory pressure (PIP), and driving pressure (DP) in the first 7 days of life between neonates who developed pneumothorax and those who did not. The primary outcome was pneumothorax with chest drainage necessity in the first 7 days of life. A matched control group was created in order to adjust for cofounders associated with pneumothorax (CRIB II score, birth weight, and gestational age).

RESULTS

There was no statistically significant difference in PEEP, PIP, and DP values in the first 7 days of life between extremely low birth weight neonates who had pneumothorax with chest drainage necessity and those who did not have pneumothorax, even after adjusting for potential cofounders.

CONCLUSIONS

Pressure-related ventilatory settings in mechanically ventilated extremely low birth weight neonates are not associated with a higher risk of pneumothorax in the first 7 days of life.

Optimizing noninvasive respiratory support during postnatal stabilization: video-based analysis of airway maneuvers and their effects

OBJECTIVE

Noninvasive respiratory support during postnatal transition may be challenging. Thus, we aimed to analyze frequency and effects of maneuvers to improve noninvasive respiratory support in neonates immediately after birth.

MATERIALS AND METHODS

We included neonates born between September 2009 and January 2015 who were video recorded as part of prospective observational studies and required noninvasive respiratory support during the first 15 min after birth. Maneuvers to improve respiratory support were assessed by video analysis. Vital parameter measurement using pulse oximetry and near-infrared spectroscopy was supplemented by respiratory function monitoring.

RESULTS

One-hundred forty-three of 653 eligible neonates (21.9%) required respiratory support. Video recordings were analyzed in 76 preterm and 58 term neonates, showing airway maneuvers in 105 of them (78.4%). Repositioning of the face mask was the most common maneuver (56.9%). We observed a median of three maneuvers (0-22) in preterm and a median of two maneuvers (0-13) in term neonates (p = .01). Regional cerebral tissue oxygen saturation was significantly higher during the 60 s after the first airway maneuver.

CONCLUSION

Maneuvers to improve respiratory support are commonly required during neonatal resuscitation, with a higher incidence in preterm neonates. The first airway maneuver was associated with an improvement of cerebral tissue oxygenation.

Risk factor analysis of pneumothorax associated with persistent pulmonary hypertension of the newborn in Thai neonates

Objective: To determine the risk factors and outcomes of persistent pulmonary hypertension of the newborn (PPHN)-associated pneumothorax (PTX).Study design: The medical records of infants diagnosed with PPHN with or without PTX from January 2012 to July 2017 were retrospectively reviewed.Results: Of the 102 included PPHN infants, PTX was found in 32 (31.4%) infants with 43.8% (14/32) mortality. PTX was significantly associated with increased mortality with an odds ratio (OR) of 5.27 (95% confidence interval [CI] 1.96-14.17). Unilateral PTX was more common than bilateral PTX (53.1 versus 46.9%, respectively). Multivariate logistic regression analysis indicated that a 1-minute Apgar score of ≤7 was associated with an increased risk for PTX (adjusted OR = 2.67 [95% CI 1.14-6.25]). In subgroup analysis, each increase of maximum peak inspiratory pressure (PIP) of 1 cmH₂O significantly increased the odds of PTX by 1.46 (95% CI 1.02-2.07), while each 1 mmHg increase in arterial partial pressure of oxygen (P_aO₂) decreased the odds of PTX (adjusted OR = by 0.98 [95% CI 0.97-0.99]).Conclusions: PTX was significantly associated with higher mortality in PPHN infants. Lower Apgar score and increasing PIP in conventional mechanical ventilation were risk factors for PTX. Higher P_aO₂ was associated with a decreased rate of PTX.

Risk Factors and Outcome of Neonatal Pneumothorax in Tuzla Canton

AIM

The aim of this study was to analyze risk factors and outcome of neonatal pneumothorax in Tuzla Canton.

METHODS

Neonates with chest X-ray confirmed pneumothorax in University Clinical Center of Tuzla, within a three-year period, from January 2015 to December 2017, were retrospectively studied. Participants were evaluated for baseline characteristics, predisposing factors of neonatal pneumothorax, accompanying disorders and mortality.

RESULTS

During the observed three-year period 11425 neonates were born in Tuzla Canton, with 7.33 % of preterm births, and 604 neonates were treated in NICU, with 265 neonates who required mechanical ventilation. Neonatal pneumothorax (NP) was diagnosed in 22 patients (9 term, 13 preterm), 12 (54.5%) were male. The incidence was 0.20% of total births, respectively 3.64% of those treated in NICU. The mean gestational age were 35.1 ± 3.0 weeks and birth weight 2 506.8 ± 727.7 grams. NP was mostly unilateral (72.7%) and right-sided. The most commonly associated diseases were: respiratory distress syndrome, intracranial haemorrhage, pneumonia, transient tachypnea and sepsis. In 8 (36.4%) neonates, the underlying cause of NP could be mechanical ventilation (secondary), whereas in 14 (63.6%) NP was spontaneous, without previous mechanical ventilation, although 11 of them required mechanical ventilation after pneumothorax.

CONCLUSION

All perinatal risk factors were investigate, and significant differences in two observed groups related to mechanical ventilation were found for birth weight, gestational age, Caesarean section, length of mechanical ventilation, surfactant replacement therapy and outcome. Three (13.64%) neonates with NP died, and among risk factors with poor outcome, significant was only Apgar score in the first minute ≤ 5.

Respiratory Care for the Ventilated Neonate

Invasive ventilation is often necessary for the treatment of newborn infants with respiratory insufficiency. The neonatal patient has unique physiological characteristics such as small airway caliber, few collateral airways, compliant chest wall, poor airway stability, and low functional residual capacity. Pathologies affecting the newborn's lung are also different from many others observed later in life. Several different ventilation modes and strategies are available to optimize mechanical ventilation and to prevent ventilator-induced lung injury. Important aspects to be considered in ventilating neonates include the use of correct sized endotracheal tube to minimize airway resistance and work of breathing, positioning of the patient, the nursing care, respiratory kinesiotherapy, sedation and analgesia, and infection prevention, namely, the ventilator-associated pneumonia and nosocomial infection, as well as prevention and treatment of complications such as air leaks and pulmonary hemorrhage. Aspects of ventilation in patients under ECMO (extracorporeal membrane oxygenation) and in palliative care are of increasing interest nowadays. Online pulmonary mechanics and function testing as well as capnography are becoming more commonly used. Echocardiography is now a routine in most neonatal units. Near infrared spectroscopy (NIRS) is an attractive tool potentially helping in preventing intraventricular hemorrhage and periventricular leukomalacia. Lung ultrasound is an emerging tool of diagnosis and can be of added value in helping monitoring the ventilated neonate. The aim of this scientific literature review is to address relevant aspects concerning the respiratory care and monitoring of the invasively ventilated newborn in order to help physicians to optimize the efficacy of care.

Pneumoperitoneum without Intestinal Perforation in a Neonate: Case Report and Literature Review

Pneumoperitoneum in a preterm neonate usually indicates perforation of the intestine and is considered a surgical emergency. However, there are cases of pneumoperitoneum with no evidence of rupture of the intestine reported in the literature. We report a case of pneumoperitoneum with no intestinal perforation in a preterm neonate with respiratory distress syndrome who was on high frequency oscillatory ventilation (HFOV). He developed bilateral pulmonary interstitial emphysema with localized cystic lesion, likely localized pulmonary interstitial emphysema, and recurrent pneumothoraces. He was treated with dexamethasone to wean from the ventilator. Pneumoperitoneum developed in association with left sided pneumothorax following mechanical ventilation and cardiopulmonary resuscitation. Pneumoperitoneum resolved after the pneumothorax was resolved with chest tube drainage. He died from acute cardiorespiratory failure. At autopsy, there was no evidence of intestinal perforation. This case highlights the fact that pneumoperitoneum can develop secondary to pneumothorax and does not always indicate intestinal perforation or require exploratory laparotomy.

Neonatal Pneumothorax: A Descriptive Regional Danish Study

BACKGROUND

Neonatal pneumothorax (PTX) can occur due to underlying pulmonary disease and/or ventilatory support. PTX can also develop at the onset of respiration. PTX can be life-threatening, and prompt diagnosis is essential to reduce mortality.

OBJECTIVE

To analyse aetiology, demographic aspects, age at diagnosis, required treatment (specifically drainage), and prognosis of all cases of neonatal PTX observed in the North Jutland Region of Denmark from 1 January 2006 to 31 December 2014.

METHOD

Retrospective, descriptive, population-based cohort study.

RESULTS

During the study period there were 48,968 live births and 71 cases of PTX, giving an incidence of PTX of 0.14% (95% Cl: 0.11-0.18). Of these, 21% were bilateral and 59% tension PTX. Fifty-two percent of neonates affected were born at term. Almost all neonates had underlying lung disease, most commonly transient tachypnea of the newborn (TTN) in 39% and respiratory distress syndrome (RDS) in 42%. Only 3% were considered to have developed PTX at the onset of respiration. In preterm neonates, the median age at diagnosis was 28.5 h (IQR: 18.3-48.6), whereas in infants born at term the median age was 6.1 h (IQR: 1.1-17.2) (p < 0.001). Thirteen percent of PTX infants died. Fifty-nine percent of the infants required drainage of the PTX, more frequently those with RDS than TTN.

CONCLUSION

Almost all infants with PTX had underlying lung disease, divided equally between RDS and TTN. The diagnosis of PTX was made earlier in infants with TTN than RDS. Neonates with RDS required drainage more often than those with TTN.

Frequency and intensive care related risk factors of pneumothorax in ventilated neonates

Objectives. Relationships of mechanical ventilation to pneumothorax in neonates and care procedures in particular are rarely studied. We aimed to evaluate the relationship of selected ventilator variables and risk events to pneumothorax. Methods. Pneumothorax was defined as accumulation of air in pleural cavity as confirmed by chest radiograph. Relationship of ventilator mode, selected settings, and risk procedures prior to detection of pneumothorax was studied using matched controls. Results. Of 540 neonates receiving mechanical ventilation, 10 (1.85%) were found to have pneumothorax. Respiratory distress syndrome, meconium aspiration syndrome, and pneumonia were the underlying lung pathology. Pneumothorax mostly (80%) occurred within 48 hours of life. Among ventilated neonates, significantly higher percentage with pneumothorax received mandatory ventilation than controls (70% versus 20%; P < 0.01). Peak inspiratory pressure >20 cm H₂O and overventilation were not significantly associated with pneumothorax. More cases than controls underwent care procedures in the preceding 3 hours of pneumothorax event. Mean airway pressure change (P = 0.052) and endotracheal suctioning (P = 0.05) were not significantly associated with pneumothorax. Reintubation (P = 0.003), and bagging (P = 0.015) were significantly associated with pneumothorax. Conclusion. Pneumothorax among ventilated neonates occurred at low frequency. Mandatory ventilation and selected care procedures in the preceding 3 hours had significant association.

Transient decrease in PaCO(2) and asymmetric chest wall dynamics in early progressing pneumothorax

PURPOSE

Diagnosis of pneumothorax (PTX) in newborn infants has been reported as late. To explore diagnostic indices for early detection of progressing PTX, and offer explanations for delayed diagnoses.

METHODS

Progressing PTX was created in rabbits (2.3 ± 0.5 kg, n = 7) by injecting 1 ml/min of air into the pleural space. Hemodynamic parameters, tidal volume, EtCO(2), SpO(2), blood gas analyses and chest wall tidal displacements (TDi) on both sides of the chest were recorded.

RESULTS

(Mean ± SD): A decrease in SpO(2) below 90 % was detected only after 46.6 ± 11.3 min in six experiments. In contrary to the expected gradual increase of CO(2), there was a prolonged transient decrease of 14.2 ± 4.5 % in EtCO(2) (p < 0.01), and a similar decrease in PaCO(2) (p < 0.025). EtCO(2) returned back to baseline only after 55.2 ± 24.7 min, and continued to rise thereafter. The decrease in CO(2) was a mirror image of the 14.6 ± 5.3 % increase in tidal volume. The analysis of endotracheal flow and pressure dynamics revealed a paradoxical transient increase in the apparent compliance. Significant decrease in mean arterial blood pressure was observed after 46.2 ± 40.1 min. TDi provided the most sensitive and earliest sign of PTX, decreasing on the PTX side after 16.1 ± 7.2 min. The TDi progressively decreased faster and lower on the PTX side, thus enabling detection of asymmetric ventilation.

CONCLUSIONS

The counterintuitive transient prolonged decrease in CO(2) without changes in SpO(2) may explain the delay in diagnosis of PTX encountered in the clinical environment. An earlier indication of asymmetrically decreased ventilation on the affected side was achieved by monitoring the TDi.

Evaluation of neonatal pneumothorax

Pneumothorax progresses quickly in newborns and can lead to death. This study collected data prospectively over a 2-year period on risk factors, clinical course and prognostic factors of newborn cases diagnosed and treated for pneumothorax. Thirty patients were evaluated for risk factors including concurrent disease, method and duration of chest drainage, oxygen saturation and mechanical ventilation. Pneumothorax developed mostly in male and mature infants during the first 48 h following birth; risk factors included concurrent respiratory distress syndrome and meconium aspiration. Mechanical ventilation was undertaken in 18 (60%) of the patients. Closed-tube drainage was used in 28 (93%) of the patients. Nine out of 10 patients (90%) whose oxygen saturation remained < 90% died. Thus, pneumothorax may develop during the neonatal period, especially in the presence of risk factors, and neonates with < 90% oxygen saturation, despite treatment, have a high mortality rate.

Prophylactic or early selective surfactant combined with nCPAP in very preterm infants

OBJECTIVE

Early surfactant followed by extubation to nasal continuous positive airway pressure (nCPAP) compared with later surfactant and mechanical ventilation (MV) reduce the need for MV, air leaks, and bronchopulmonary dysplasia. This randomized, controlled trial investigated whether prophylactic surfactant followed by nCPAP compared with early nCPAP application with early selective surfactant would reduce the need for MV in the first 5 days of life.

METHODS

A total of 208 inborn infants who were born at 25 to 28 weeks' gestation and were not intubated at birth were randomly assigned to prophylactic surfactant or nCPAP within 30 minutes of birth. Outcomes were assessed within the first 5 days of life and until death or discharge of the infants from hospital.

RESULTS

Thirty-three (31.4%) infants in the prophylactic surfactant group needed MV in the first 5 days of life compared with 34 (33.0%) in the nCPAP group (risk ratio: 0.95 [95% confidence interval: 0.64-1.41]; P = .80). Death and type of survival at 28 days of life and 36 weeks' postmenstrual age and incidence of main morbidities of prematurity (secondary outcomes) were similar in the 2 groups. A total of 78.1% of infants in the prophylactic surfactant group and 78.6% in the nCPAP group survived in room air at 36 weeks' postmenstrual age.

CONCLUSIONS

Prophylactic surfactant was not superior to nCPAP and early selective surfactant in decreasing the need for MV in the first 5 days of life and the incidence of main morbidities of prematurity in spontaneously breathing very preterm infants on nCPAP.

Pulmonary complications of mechanical ventilation in neonates

Mechanical ventilation is necessary and life saving in many neonates. Most complications are inherent to this intervention and cannot be confused with iatrogenic errors in judgment or care practices by clinicians. Clinical data suggest that complications such as volutrauma and air leak syndromes can negatively affect long-term pulmonary and non-pulmonary outcomes. Careful attention to many aspects of neonatal care, such as delivery room resuscitation, ventilatory support, and routine care practices, is needed to decrease pulmonary complications of mechanical ventilation. Clinical research is needed to improve mechanical ventilator strategies to reduce pulmonary complications and improve long-term outcomes.