Incidence Of Pulmonary Interstitial Emphysema Research Articles

Computed tomography findings of pulmonary interstitial emphysema in COVID-19: Looking through the lens.

Sir, We read Scialpi et al.’s[1] study evaluating the incidence of pulmonary interstitial emphysema (PIE) and other complications detected using computed tomography (CT) in COVID-19 patients. Although the findings are clinically relevant, some key aspects need to be clarified to define a specific impact and better understand. The authors emphasise early detection of the complications using CT that might help us optimise the ventilation option (noninvasive/invasive ventilation) to reduce the severity of complications. Although the basis is essential, there is controversy about the role of applied ventilation options, especially noninvasive ventilation (NIV) as an inducing factor of PIE or as a promoting factor.[2] In this sense, we also do not know how they can be identified and how to establish a better prevention strategy? The authors have summarised the number of PIE patients who received NIV and invasive mechanical ventilation (IMV). The relationship between PIE and NIV will be interesting. We could not establish an adequate interpretation and relationship of NIV with the PIE or other complications as comparative data required are lacking in the authors’ presented data. COVID-19 patients tend to have a higher incidence of barotrauma with IMV.[23] In this context, a comparison of PIE incidence in patients treated with NIV and IMV will help decide the mode of ventilation. Further, the airway pressures and ventilatory pressure setup in PIE and non-PIE patients receiving NIV will also help us optimise settings.[4] Further, we could not find precise mechanisms and possibilities that determine the evolution of different forms of PIE. In the authors’ cohort, variations in PIE were revealed in 25 patients and associated with pneumomediastinum, subcutaneous emphysema, and pneumothorax in 25 (100%), 16 (64%), and 7 (28%), respectively.[1] However, the determining factors that explain this variation allowing the framework of lung-protective strategies, prevention, and early diagnosis in high-risk patients are missing. It will be helpful for the readers if the authors present any such data from the cohort. It will help us plan future studies to evaluate the best tool for prevention and treatment. Author contribution HMRK, AME–observation, literature search, manuscript preparation, and editing. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.

Data collection from very low birthweight infants in a geographical region: Methods, costs, and trends in mortality, admission rates, and resource utilisation over a five-year period

Aims 1. To determine the survival and morbidity of infants at discharge with a birthweight of less than 1500 g in the geographically defined population of East Anglia. 2. To demonstrate a cost-effective method of regional data collection. 3. To determine whether there were any changes in the demand for neonatal care. Study design and subjects A prospective cohort analysis using a single database to collect data on 1244 very low birthweight infants from eight neonatal units in one Region from 1993 to 1997. Results Estimated ascertainment of VLBW infants to the study was 96%. Over the 5 years survival rates were stable (75–79%). 52% of deaths in infants admitted for neonatal care occurred on day 1, with just 15% of deaths occurring after 28 days of life. Mortality risk significantly decreased with increasing gestational age at birth. Compared to 22–25-week old infants, the mortality risk decreased by 65% for 26–27-week old infants (OR 0.35 95% CI (0.21, 0.59)) and by 92% for 32–39-week old infants (OR 0.08 95% CI (0.03, 0.21)) with intermediate odds ratios of 0.22 (0.12, 0.42) and 0.13 (0.06, 0.28) for the 28–29 and 30–39 weeks gestation, respectively. Higher birthweight, after adjusting for gestation also decreased the mortality risk (OR 0.78 per 100 g difference, 95% CI (0.71, 0.86)). No change was seen in the number of extremely preterm infants admitted for intensive care or resource utilisation, although a significant increase was seen in the number of infants dying in delivery rooms. There was a reduction in the reported incidence of pulmonary interstitial emphysema (10–4%) but no change in the number of ventilation days or the rate of chronic lung disease. The mean maternal age increased from 27.7 years to 28.9 years during the study. Maternal steroid administration increased (30% to 59%) and was associated with a decreased risk of mortality (OR 0.44, 95% CI: 0.31–0.62). Conclusions It is possible to collect useful data from the neonatal period at a reasonable cost from a geographically defined population. This information was used for informing clinicians, counselling parents and in the era of managed clinical networks will be useful in guiding the provision of effective health care resources.

Prophylactic versus selective use of surfactant for preventing morbidity and mortality in preterm infants.

This section is under preparation and will be included in the next issue. To compare the effect of prophylactic surfactant administration to surfactant treatment of established respiratory distress syndrome in premature infants. Searches were made of the Oxford Database of Perinatal Trials, Medline (MeSH terms: pulmonary surfactant; limits: age groups, newborn infants), previous reviews including cross-references, abstracts, conference and symposia proceedings, expert informants, and journal handsearching in the English language. Randomized controlled trials which compared the effects of prophylactic surfactant administration to surfactant treatment of established respiratory distress syndrome in premature infants were included in the analysis. Data regarding clinical outcomes including the incidence of pneumothorax, pulmonary interstitial emphysema, patent ductus arteriosus, necrotizing enterocolitis, intraventricular hemorrhage (any grade and severe intraventricular hemorrhage), bronchopulmonary dysplasia, mortality, bronchopulmonary dysplasia or death, and retinopathy of prematurity were excerpted from the reports of the clinical trials by the reviewers. Data analysis was done in accordance with the standards of the Cochrane Neonatal Review Group. The majority of included studies noted an initial improvement in the respiratory status and a decrease in the incidence of respiratory distress syndrome in infants who received prophylactic surfactant. The meta-analysis supports a decrease in the incidence of pneumothorax, a decrease in the incidence of pulmonary interstitial emphysema, a decrease in the incidence of mortality and a decrease in the incidence of bronchopulmonary dysplasia or death associated with prophylactic administration of surfactant. No significant untoward effects of prophylactic surfactant administration are noted. Prophylactic surfactant administration to infants judged to be at risk of developing respiratory distress syndrome (intubated infants less than 30-32 weeks gestation) has been demonstrated to improve clinical outcome. Infants who receive prophylactic surfactant have a decreased incidence of pneumothorax, a decreased incidence of pulmonary interstitial emphysema and a decreased incidence of mortality. However, it remains unclear exactly which criteria should be used to judge "at risk" infants who would require prophylactic surfactant administration.

The relationship of pulmonary interstitial emphysema to subsequent type of chronic lung disease.

Chronic lung disease of prematurity (CLD) can be classified using the chest radiograph taken on day 28 into type 1 (homogeneous opacification) or type 2 (the presence of cystic change) and it has been suggested that the presence of pulmonary interstitial emphysema (PIE) leads to the development of type 2 CLD. To further study this relationship we examined the chest radiographs taken on days 1-7, 14, 21 and 28, of 202 infants treated at Liverpool Maternity Hospital between January 1980 and December 1989 who developed CLD. 39% (54/137) of infants who developed type 1 CLD had suffered from PIE compared with 78% (51/65) with type 2 CLD (p < 0.001). There was no difference in the incidence of PIE in infants who developed CLD and subsequently died compared with those who survived. In the infants who survived there was no significant difference in length of oxygen dependency between those who suffered from PIE (median 99 days oxygen dependent) and those who had no PIE (median 105 days). We conclude that the presence of PIE is associated with subsequent development of type 2 CLD but is not a prerequisite for this radiographic type of chronic lung disease. Of those infants who survive to develop CLD, the presence of PIE does not alter prognosis in terms of duration of oxygen dependency or mortality.

Expectant management of preterm premature rupture of the membranes

Our purpose was to (1) evaluate expectant management of preterm premature rupture of the membranes between 20 and < 36 weeks' gestation and (2) compare outcomes in service and private populations. The study included only singleton pregnancies prospectively managed between 20 and < 36 weeks' gestation with proved preterm premature rupture of the membranes. None of the patients received prophylactic antibiotics, tocolytics, or steroids, and none of the neonates received surfactant or had lethal anomalies. Patients (n = 511) were divided into private (n = 194) and staff (n = 317) categories, but all were managed identically. Approximately 50% of patients were delivered within 48 hours. Infection is more likely with preterm premature rupture of membranes before 28 weeks' gestation (p = 0.001), as is fetal death associated with infection (p < 0.001). Other findings in this study were (1) no significant differences in evaluated outcomes between private and staff patients, except that significantly more vaginal deliveries occurred in staff patients, (2) a prolongation of pregnancy > or = 7 days in 12.9% of patients, (3) a significant increase in the rate of maternal infection if preterm rupture of membranes occurred before 28 weeks' gestation, (4) a significant increase in fetal and neonatal deaths if preterm premature rupture of membranes occurred before 28 weeks, and (5) an increased probability of survival whose rate of increase is dependent on the gestational age at which preterm premature rupture of membranes occurred. For babies weighing < 1500 gm at birth compared with controls, babies delivered of mothers not having preterm premature rupture of membranes, 1-year follow-up revealed (1) a significantly lower incidence of pulmonary interstitial emphysema and cerebral palsy in the study group delivered before 28 weeks' gestation, (2) a significantly lower incidence in bronchopulmonary dysplasia in the study group delivered after 28 weeks' gestation, and (3) no significant differences in the incidence of intraventricular hemorrhage, pneumothorax, or Bayley Mental Developmental Index < 68 between those delivered before or after 28 weeks' gestation. Over 47.8% of the patients continued their pregnancy beyond 48 hours, and in 12.9% of cases expectant management of preterm premature rupture of membranes prolonged the pregnancy by > or = 7 days. The maternal infection rate is greater before 28 weeks' gestation and is associated with higher fetal-neonatal mortality. Status has little impact on outcome. Expectant management is not detrimental to quality of survival. Survival probability increases at a more rapid rate with preterm premature rupture of membranes after 22 weeks of gestation.

High‐dose versus low‐dose bovine surfactant treatment in very premature infants

The aim of the study was to determine if high-dose bovine surfactant (Alveofact, initially 100 mg/kg birth weight) would improve oxygenation compared with low-dose surfactant (50 mg/kg birth weight) administered intratracheally within 1 h after birth. Inclusion criteria included gestational age 24-29 weeks and birth weight 500-1500 g, intubation and mechanical ventilation, absence of congenital malformations and bacterial infections. Retreatment was considered if the fraction of inspired oxygen (FiO2) was > 0.4 (dose 50 mg/kg birth weight). The primary endpoint was level of oxygenation (PaO2/FiO2) 2 h after treatment. The study design was a sequential analysis using a triangular test with alpha = 0.05 and 95% power to detect a 25% improvement in the endpoint. Oxygenation was improved significantly with high-dose (n = 42) compared to low-dose treatment (n = 48): 30.9 +/- 15.0 kPa (231.5 +/- 112.7 mmHg) versus 24.1 +/- 15.7 kPa (180.6 +/- 118.0 mmHg) (mean +/- SD). The survival rate was 83% in both groups and the incidence of pulmonary interstitial emphysema was 33% versus 14% with the high-dose treatment. We conclude that high-dose surfactant significantly improved oxygenation and reduced lung barotrauma. An initial dose greater than 50 mg/kg birth weight of surfactant is required for optimal acute response.

Surfactant replacement therapy in neonates less than 32 weeks gestation: Effect on neonatal intensive care resource utilization

The effect of synthetic surfactant (Exosurf) replacement on complications from hyaline membrane disease (HMD) in infants < 32 weeks gestation and their resource utilization within a neonatal intensive care unit was studied in 1991-92. A control group was selected from infants admitted to the same unit during the preceding 3 years when Exosurf was not available. The infants were controlled for gestation, weight and severity of HMD. Infants given Exosurf had a significant reduction in the incidence of pulmonary interstitial emphysema (PIE), and a marginal decrease in the incidence of pneumothorax. They required fewer days on the ventilator and consumed less of the scarce financial resources. There was no difference in the mortality rate among the two groups. The changes seen were more evident among those infants between 30 and 31 weeks gestation, compared to those < 28 weeks.

Effects of two rescue doses of a synthetic surfactant on mortality rate and survival without bronchopulmonary dysplasia in 700- to 1350-gram infants with respiratory distress syndrome

In a multicenter, double-blind, placebo-controlled rescue trial conducted at 21 American hospitals, two 5 ml/kg doses of a synthetic surfactant (Exosurf Neonatal) or air were administered to 419 infants weighing 700 to 1350 gm who had respiratory distress syndrome and an arterial/alveolar oxygen pressure ratio less than 0.22. The first dose was given between 2 and 24 hours of age; the second dose was given 12 hours later to those infants remaining on ventilatory support. Infants were stratified at entry by birth weight and gender. Among infants receiving synthetic surfactant, improvements in alveolar-arterial oxygen pressure gradient, arterial/alveolar oxygen pressure ratio, and oxygen and ventilator needs through 7 days of age were apparent. Death from respiratory distress syndrome was reduced by two thirds (21 vs 7; p = 0.007), and the overall neonatal mortality rate was reduced by half (50 vs 23; p = 0.001). Although there was no significant reduction in the incidence of bronchopulmonary dysplasia (39 vs 31; p = 0.107), the hypothesis that survival through 28 days without bronchopulmonary dysplasia would be enhanced by two rescue doses of synthetic surfactant was proved true (21% improvement, from 132 to 156 patients; p = 0.001). In addition, the incidence of pneumothorax was reduced by one third (62 vs 40; p = 0.022), and the incidence of pulmonary interstitial emphysema was reduced by half (102 vs 51; p = 0.001). The only side effect identified was an increase in the incidence of apnea (102 vs 134; p = 0.001). These findings indicate that rescue use of a synthetic surfactant can improve the morbidity and mortality rates for premature infants with respiratory distress syndrome.

Surfactant Replacement Therapy for Severe Neonatal Respiratory Distress Syndrome: An International Randomized Clinical Trial

In a randomized multicenter trial, involving the collaboration of eight European neonatal intensive care units, the efficacy of replacement therapy with a new surfactant preparation (Curosurf) was tested in 146 patients with severe neonatal respiratory distress syndrome. Criteria for entry included birth weight 700 to 2,000 g, age when treated two to 15 hours, and requirement of artificial ventilation with Fio2 ≥ 0.6. The babies were treated with a single large dose of surfactant (200 mg/kg) at a median age of nine hours (range two to 15 hours). Average Fio2 before treatment was the same (0.80) for both surfactant-treated patients and control patients. Babies receiving surfactant showed, within five minutes, a dramatic improvement of oxygenation as reflected by a nearly threefold increase of the Pao2/Fio2 ratio. Six hours after randomization, the Pao2/Fio2 ratio still showed a 98% improvement in surfactant-treated patients compared with controls (P &amp;lt; .001), and statistically significant differences in favor of the treated babies persisted until 48 hours after randomization, when surviving control infants began to recover. Treatment with surfactant decreased neonatal (≤28 days) mortality from 51% to 31% (P &amp;lt; .05). Compared with control babies, the surfactant-treated group also had a decreased incidence of pulmonary interstitial emphysema (23% v 39%; P &amp;lt; .05) and pneumothorax (18% v 35%; P &amp;lt; .05). The percentage of survivors without bronchopulmonary dysplasia in the treated group was more than twice that of the control group (55% v 26%; P &amp;lt; .001). Treatment with this surfactant appears to effectively improve lung function and short-term outcome in infants with severe respiratory distress syndrome.

Chest tube perforation of the lung in premature infants: radiographic recognition.

Newborn infants with severe respiratory distress syndrome have an increased incidence of pulmonary interstitial emphysema, pneumomediastinum, and pneumothorax. A chest tube inserted for treatment of a pneumothorax may inadvertently perforate the lung. Recognition of chest tube perforation can be suggested by the occurrence of: (1) persistent or repeated pneumothoraces despite the presence of a chest tube and (2) atelectasis and/or infiltrate near the end of the chest tube.