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Pulmonary Interstitial Emphysema in a Full-Term Infant: Do We Know the Incidence?

2003; King Faisal Specialist Hospital and Research Centre; Volume: 23; Issue: 3-4 Linguagem: Inglês

10.5144/0256-4947.2003.191

0975-4466

Husam Salama, Latifa Al Mahmood, Abdulhakiem Kattan, M Al Assmi, A. Rejjal,

Trauma Management and Diagnosis

Case ReportsPulmonary Interstitial Emphysema in a Full-Term Infant: Do We Know the Incidence? Husam Salama, MD Latifa Al Mahmood, MD Abdulhakiem Kattan, MD M Al Assmi, and MD Abdulatif RejjalMP Husam Salama From the Department of Pediatrics, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabi Search for more papers by this author , Latifa Al Mahmood From the Department of Pediatrics, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabi Search for more papers by this author , Abdulhakiem Kattan From the Department of Pediatrics, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabi Search for more papers by this author , M Al Assmi From the Department of Pediatrics, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabi Search for more papers by this author , and Abdulatif Rejjal Correspondence to: Dr. A. Rejjal, P.O. Box 3354 MBC 58, Saudi Arabia From the Department of Pediatrics, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabi Search for more papers by this author Published Online:1 May 2003https://doi.org/10.5144/0256-4947.2003.191SectionsPDF ToolsAdd to favoritesDownload citationTrack citations ShareShare onFacebookTwitterLinked InRedditEmail AboutIntroductionPulmonary interstitial emphysema (PIE) occurs predominantly in premature infants exposed to mechanical ventilation. In the modern literature, pneumothorax is the most common form of air leak syndrome in full-term infants of average weight, while the incidence of PIE in the same age group is not known. We report a case of a full-term infant who developed severe PIE secondary to aggressive conventional mechanical ventilation that responded to selective intubation and high frequency oscillatory ventilation. In addition, we review the incidence reported in the literature of PIE affecting full-term newborns.CASE REPORTA 3-day old full-term male infant, with a birth weight of 3.4 kilograms, was transferred from a district hospital because of deterioriation of respiratory function despite high mechanical ventilation requirements. The mother was a healthy, 35-year old (gravida 5, para 4) and a non-smoker. There was no maternal history to suggest infection. The family history was unremarkable. The infant was born by emergency cesarian delivery because of fetal distress and a thin meconium. The Apgar score was 6 at the first minute and 8 at the fifth minute. There was a minimal, thin meconium below the vocal cord on tracheal suctioning. The infant was showing signs of respiratory distress and was admitted to the neonatal intensive care for close monitoring.The infant’s condition became worse and his FiO2requirement increased constantly with deterioration of arterial blood gas. He had to be intubated and conventional mechanical ventilation was initiated. A chest x-ray demonstrated a mild increase in bronchovascular markings, with no evidence of lung opacities. The infant’s blood gas one hour after intubation was not improving and showed evidence of severe hypoxemia (PaO2 of 30 mm Hg and PCO2of 42 mm Hg). Positive inspiratory pressure (PIP) was increased steadily until it was 37 cm H2O at 18 hours of age with anFiO2 of 1 (100% oxygen) and a respiratory rate of 70per minute to maintain oxygen saturation between 85% to 90% on the monitor. At 24 hours of age, the ventilatory requirements increased and a chest x-ray showed evidence of diffuse pulmonary interstitial emphysema involving the whole left lung, complicatedshortly by tension pneumothorax that required chest tube insertion. On arrival at our NICU, the infant was extremely sick with unstable vital signs, an oxygen saturation of 80%, and severe metabolic and respiratory acidosis (pH of 7.1 and PaO2 of 40 mm Hg, PCO2 of 58 mm Hg and HCO3 of 14 mm Hg). He was receiving mechanical ventilation with a PIP/PEEP (positive inspiratory and end-expiratory pressure) of 40/4 cm H2O, an inspiratory time of 0.7, and 100% oxygen. The infant was placed on high frequency oscillatory ventilation while inhaled nitric oxide was initiated 2 hours later at 20 parts per million as hypoxia persisted. Based on the severity of the emphysema and the unusual presentation of the condition, a CT scan of the chest was performed, once the patient was stabilized, to exclude other diagnoses, particularly congenital cystic adenomatoid malformation and congenital lobar emphysema.The CT scan result (Figure 1) confirmed PIE as the diagnosis. We performed a selective intubation of the right bronchus (by slow advancement of the endotracheal tube aimed at the collapsed left lung and guided by serial chest x-ray) for 36 hours. The chest x-ray series showed significant improvement in the extent and intensity of the PIE and improvement of the pneumothorax (Figure 2). The chest tube was removed after 48 hours, and the infant was extubated 2 days later. Blood, skin, endotracheal and gastric washout culture results from both hospitals were all negative. Theinfant was discharged home at 2 weeks of age. An alpha-1 antitrypsine assay was within normal limits in both the mother and infant. Echocardiography showed that renal and hepatic ultrasounds were within normal limits. Follow up at 2 and 6 months of age in the outpatient clinic was satisfactory.Figure 1. CT scan of the abdomen, post contrast showing severe ascitis and scalloping of the liver boarders. Note the free intraperitoneal air interiorly.Download FigureFigure 2. Selective intubation of the right main bronchus. Note the collapse of the whole left lung and the upper zone of the right lung as well.Download FigureDISCUSSIONPulmonary interstitial emphysema is a well-defined complication of positive pressure mechanical ventilation.1 The basic pathology is dissemination of air in the interstitial space between the alveoli secondary to rupture of the alveolar base at its junction with the less expandable fluid-rich perivascular connective tissue. Subsequent air leakage into the perivascular sheath dissects the sheath along peribroncheal and perivascular spaces from ruptured alveoli.2,3 Wood et al. demonstrated that the leaked air lies within the dilated lymphatics of the interlobular septae and visceral pleura.4In our case, there was a history of a minimal thin meconium below the vocal cord, which was not consistent with the severity of the PIE. Avery in 1963 described a mechanism by which a meconium plug at the bronchial tree may create a one-way valve (ball valve) that can cause air trapping, increase intra-alveolar pressure, and cause development of PIE.5Why are premature lungs more prone to develop PIE than the lungs of full-term infants?The interstitium in the premature lung differs from the interstitium in the term lung in having less connective tissue, and more water content, while both the alveolar surface and the lung elastic tissue forces are higher. These characteristics allow gas to spread extensively through the connective tissue and become diffuse, before progression into pneumothorax, or pneumomediastinum. The water content in the interstitium will impede the flow of gas into the perivascular spaces.6 The integrity of the lymphatic wall and cohesion of theperivascular spaces is still not well developed and is fragile in the premature lung, which allows gas to dissect through easily before it ruptures into the pleural cavity.6,7 Another factor that very likely contributes to alveolar rupture is a deficiency in both the size and number of connecting channels between the alveoli (pores of Kohn) and between the brochioles and the adjacent alveoli (channels of Lambert).2 The lack of an escape mechanism hampers the redistribution of air from the over-ventilated alveoli to adjacent nonventilated alveoli and bronchioles, which creates unbalanced mechanical stress and subsequently increases the likelihood of alveolar rupture.3Mechanical Ventilation and Development of Interstitial EmphysemaThe high incidence of air leaks during assisted ventilation has been attributed to barotraumas caused by the high level of inspiratory pressure and excessive prolongation of inspiratory time. These may be the major two risk factors in the pathogenesis of air leaks. Oppermann showed that the magnitude of the PIP (more than 40 cm H2O) was more important than the inspiratory time in the development of PIE. None of the PIE cases in his observations received a PIP of more than 40 cm H2O.8 The same finding (mean inspiratory pressure at rupture time more than 30-40 cm H2O) was reported by other investigators.9,10 Emery was one of the few investigators who reported on the occurrence of PIE in full-term infants who were otherwise well. Mechanical ventilator assistance was not a factor in his study.11 Karlberg 12 recorded transpulmonary pressures during the first few breaths of life of 40 cm H2O and occasionally as high as 100 cm H2O. Chernick4,13 noticed that adult alveoli would rupture at a pressure of approximately 60 cm H2O. Comparable data are not available for newborn infants.How common is PIE among full-term newborns?There is little in the literature on this issue. The total incidence of air leak in newborns is 1-3%, a figure that includes all gestational age groups and all types of air leak syndrome. This incidence may rise to 30% in premature infants less than 32 weeks gestation and less than 2000 gram birth weight.9 Several large trials have looked at the impact of the surfactant administration on the incidence of air leak syndrome in very low birth weight infants. Kezler and colleagues conducted a randomized, multicenter trial comparing high frequency jet ventilation and conventional ventilation in the treatment of newborn infants with PIE (PIE was the main entry criteria). Among the 144 patients recruited in the trial, nonwere full term, or weighed more than 1900 grams.14 Oppermannet al looked into the rate of air embolism in newborns. Out of 25 cases in his analysis, the air embolism was preceded by PIE, pneumothorax or other air leak syndromes in 21 patients. None of the full-term newborns or infants of birth weight more than 2500 gram (4 infants)developed PIE. In addition, there was a steady increase in the incidence of more than one air leak withincreasing gestational age and reduced birth weight. Interestingly, the same relationship did not apply when only infants with pneumothorax were considered because pneumothorax is more common in term infants.8 The same outcome could be derived from Madanskyet al9 who were able to elaborate further on the relationship between the birth weight and the rate of the air leak syndrome in general. In her report, two full-term infants with meconium aspiration syndrome developed PIE diagnosed only by autopsy. In the 21 cases reported in Madansky’s review, no cases of PIE were found in the full-term age group. Pfenninger et al 10 reported on 6 full-term infants with an average weight of 3 kilograms who developed adult respiratory distress syndrome and required high ventilation settings. Three of the six developed pure isolated diffuse PIE while two developed more than one air leak syndrome. The mean PIP/PEEP was 37/7 cm H2O. If these authors observations were accurate, it means that PIE is very rare in average weight full-term newborns, even among those who receive mechanical ventilation. The incidence of PIE among this age group is not reported in the literature, and data may not exist apart from a few case reports or unreported data in large trials. It is worth emphasizing that early transfer of such critical cases to tertiary centers where high frequency ventilation and inhaled nitric oxide is available may provide more definite rescue therapy and avoid the development of complications.ARTICLE REFERENCES:1. Cample RE. "Intrapulmonary interstitial emphysema. A complication of hyaline membrane diseases" . Am J Radiol. 1970; 110:449–56. Google Scholar2. Macklin CC. "Alveolar pores and their significance in human lung" . Arch Pathol. 1936; 21:202–10. Google Scholar3. Macklin CC. "Transport of air along sheathes of pulmonic blood vessels from alveoli to mediastinum, clinical implications" . Arch Int Med. 1939; 64:913–26. Google Scholar4. Wood B, Anderson V, Mauk Je, Merritt T. "Pulmonary lymphatic air: locating pulmonary interstitial emphysema of premature infants" . AJR. 1982; 138:809–14. Google Scholar5. Chernick V, Avery ME. "Spontaneous alveolar rupture at birth" . Pediatrics. 1963; 32:816–24. Google Scholar6. Caldwell E, Powell R, Mulloy P. "Interstitial emphysema: a study in the physiologic factors involved in experimental induction of the lesion" . Am Rev Respir Dis. 1970; 102:516. Google Scholar7. Reid L, Rubino L. "The connective tissue septa in the fetal human lung" . Thorax. 1959; 14:3;35–45. Google Scholar8. Oppermann H, Wille L, Obladen M, Richter E. "Systemic air embolism in respiratory distress syndrome of the newborn" . Pediatr Radiol. 1979; 8:139–45. Google Scholar9. Madasnsky D, Lawson E, Chernick V, Taeusch H. "Pneumothorax and other forms of air leak in newborn" . Am Rev Resp Dis. 1979; 120:729–37. Google Scholar10. Pfenninger J, Tschaeppeler H, Wagner B, Weber J, Zimmerman A. "The paradox of adult respiratory distress syndrome in neonates" . Pediatric Pulmonol. 1991; 10:18–24. Google Scholar11. Emery JL. "Interstitial emphysema, pneumothorax and air block in newborn" . Lancet. 1956;405–9. Google Scholar12. Karlberg PJE. Breathing and its control in premature infants. Lanman JT (ed): Physiology of prematurity: transactions of the second conference, 1957. New York, Josiah Macy JR. Foundation. 1958. Google Scholar13. Chernick V, Reed M. "Pneumothorax and chlylothorax in neonatal period" . J Pediatrics. 1970; 4:624–32. Google Scholar14. Kezzler M, Donn S, Bucciarelli R, Alverson D, Hart M, Lunyong Vet al.. "Multicenter controlled trial comparing high frequency jet ventilation and conventional mechanical ventilation in newborn infants with pulmonary interstitial emphysema" . J Pediatrics. 1991; 1:85–92. Google Scholar Previous article Next article FiguresReferencesRelatedDetailsCited bySalama H, Hugosson C, Rejjal A, Al-Alyian S and Almahmood L (2019) Systemic Air Leak Syndrome in a Sick Full-Term Infant, Annals of Saudi Medicine , 23:5, (321-322), Online publication date: 1-Sep-2003.Salama H (2019) Reply, Annals of Saudi Medicine , 23:6, (421-421), Online publication date: 1-Nov-2003. Volume 23, Issue 3-4May-July 2003 Metrics History Accepted1 February 2003Published online1 May 2003 InformationCopyright © 2003, Annals of Saudi MedicinePDF download