Pulmonary interstitial emphysema: a case report and review of the literature / Enfisema intersticial pulmonar: relato de caso e revisão da literatura

Pulmonary interstitial emphysema is a rare condition that generally affects low-weight preterm infants submitted to mechanical ventilation. The prognosis is variable, depending on early diagnosis and treatment. The radiologist plays a key role in this scenario. The authors report a case of persistent pulmonary interstitial emphysema, describing the main characteristics of such entity.

O enfisema intersticial pulmonar é uma condição rara que acomete, em geral, recém-nascidos pré-termos de baixo peso submetidos a ventilação mecânica. O prognóstico é variável e dependente do diagnóstico e tratamento precoces, ressaltando-se a importância do radiologista neste cenário. Os autores relatam um caso de enfisema intersticial pulmonar persistente, abordando as principais características desta entidade.

Pulmonary interstitial emphysema complicating pneumonia in an unventilated term infant.

A case of pulmonary interstitial emphysema with pneumothorax and pneumomediastinum complicating pneumonia in a 6-week-old infant is reported. The patient had no history of resuscitation, bag and mask ventilation, nasal continuous positive airway pressure or mechanical ventilation.

Study of the risk factors for pulmonary interstitial emphysema related to mechanical ventilator care / 소아과

PURPOSE: Pulmonary interstitial emphysema (PIE) primarily occurs in preterm infants suffering from respiratory distress syndrome (RDS) and kept under mechanical ventilator care. Therefore, this study aimed to examine various risk factors for PIE, to identify conditions that can decrease the possibility of PIE development. METHODS: PIE classification was conducted for 183 patients diagnosed to have RDS and receiving mechanical ventilator care with pulmonary surfactant between March 2000 and February 2007. The characteristics of each patient were analyzed through retrospective examination of their medical histories. RESULTS: Among 183 patients, 17 had PIE; all factors, including birth weight, gestational age, RDS grade III or above, chorioamnionitis, and premature rupture of membranes, were statistically significant (P<0.05). The period of mechanical ventilator use was statistically significant, but the peak mean airway pressure and peak partial pressure of inspired oxygen were not. PIE mainly occurred on the right side or both sides rather than the left side and mostly developed within 72 h. The PIE group showed higher mortality rate than the control group, and the major cause of mortality was pneumothorax. CONCLUSION: Risk factors for PIE in infants suffering from RDS and kept under mechanical ventilator care include low gestational age, low birth weight, chorioamnionitis, and premature rupture of membranes. If any risk factors are noted, the infant must be observed closely for at least 72 h after birth.

Risk factors for Pulmonary Interstitial Emphysema (PIE) in Mechanically Ventilated Neonates with Hyaline Membrane Disease

PURPOSE: Pulmonary interstitial emphysema (PIE) is a common and serious complication of mechanical ventilation in infants with hyaline membrane disease. This abnormal collection of gases has two basic roentgenographic features; linear and cyst-like radiolucencies. High positive inspiratory pressure was found to be the most significant parameter associated with development of fatal pulmonary interstitial emphysema. Without prompt conservative management such as lowering peak inspiratory pressure, PIE often progress to a pneumothorax with increased mortality. We studied the incidence and risk factors of PIE and associated risk factors which progress to pneumothorax in mechanically ventilated infants with hyaline membrane disease. METHODS: We reviewed retrospectively the charts of infants who had been admitted to the neonatal intensive care unit between Jan. 1990 and Mar. 1995. A hundred and two infants who were diagnosed as hyaline membrane disease and mechanically ventilated were included in the study. Analysis of clinical characteristics and ventilator parameters were made. Chest radiographs were reviewed for hyaline membrane disease, PIE, pneumothorax by a pediatric radiologist without knowledge of their clinical course. RESULTS: 1) We observed PIE in 14 of 102 infants (13.7%) of which 11 infants progressed to develop pneumothorax. 2) Low gestational age, low apgar score and high peak inspiratory pressure were the factors significantly associated with development of PIE. 3) PIE was frequently located bilaterally (52%), distributed on whole lung parenchyme (92%). Sizes of radiolucency were variable including blebs. 4) Early onset PIE and failure to promptly lower peak inspiratory pressure were the associated risk factors for development of pneumothorax. 5) Pneumothorax developed within a mean 7.5 hours after apperance of PIE. Right side pneumothorax was more frequent (67%). Mortality increased to 73% with development of pneumothorax in PIE. CONCLUSIONS: Early diagnosis of PIE and prompt lowering of peak inspiratory pressure should be emphasized to improve the survival and outcome of mechanically ventilated hyaline membrane diasease infants.