Noninvasive Mechanical Ventilation with Average Volume-Assured Pressure Support versus BiPAP S/T in De Novo Hypoxemic Respiratory Failure.

Background: Bilevel positive airway pressure in spontaneous/time and average volume-assured pressure support (BiPAP·S/T-AVAPS) could maintain an adequate tidal volume by reducing the patient's inspiratory effort; however, this ventilatory strategy has not been compared with other ventilatory modes, especially the conventional BiPAP S/T mode, when noninvasive mechanical ventilation (NIMV) is used. The primary objective of this study was to determine the rate of success and failure of the use of BiPAP·S/T-AVAPS versus BiPAP·S/T alone in patients with mild-to-moderate "de novo" hypoxemic respiratory failure. Methods: This was a matched-cohort study. Subjects with mild-to-moderate de novo hypoxemic respiratory failure were divided into two groups according to the ventilatory strategy used. The subjects in the BiPAP·S/T group were paired with those in the BiPAP·S/T-AVAPS group. Results: A total of 58 subjects were studied. Twenty-nine subjects in the BiPAP·S/T group were paired with 29 subjects in the BiPAP·S/T-AVAPS group. Twenty patients (34.5%) presented with "failure of NIMV," while 38 (65.5%) patients did not. In addition, 13 (22.4%) patients died, while 45 (77.6%) recovered. No differences were found in the percentage of intubation (P=0.44) and mortality (P=0.1). Conclusion: The BiPAP S/T-AVAPS ventilator mode was not superior to the BiPAP·S/T mode. A high mortality rate was observed in patients with NIMV failure in both modes. This trial is registered with https://doi.org/10.1186/ISRCTN17904857.

Apnea-Hypopnea Index in Chronic Obstructive Pulmonary Disease Exacerbation Requiring Noninvasive Mechanical Ventilation with Average Volume-Assured Pressure Support.

INTRODUCTION: This study intends to determine the Apnea-Hypopnea Index in patients hospitalized with acute hypercapnic respiratory failure from chronic obstructive pulmonary disease exacerbation, who require noninvasive ventilation with average volume-assured pressure support (AVAPS), as well as describes the clinical characteristics of these patients. MATERIALS AND METHODS: We designed a single-center prospective study. The coexistence of Apnea-Hypopnea Index and clinical, gasometric, spirometric, respiratory polygraphy, and ventilatory characteristics were determined. The clinical characteristics found were categorized and compared according to the Apnea-Hypopnea Index (AHI) < 5, AHI 5-15, and AHI >15. A p value <0.05 was considered statistically significant. RESULTS: During the study period, a total of 100 patients were admitted to the ICU with a diagnosis of acute hypercapnic respiratory failure due to COPD exacerbation. 72 patients presented with acute respiratory failure and fulfilled criteria for ventilatory support. Within them, 24 received invasive mechanical ventilation and 48 NIV. After applying the inclusion criteria for this study, 30 patients were eligible. An AHI >5 was present in 24 of the 30 patients recruited (80%). Neck circumference (cm), Epworth scale, and Mallampati score evidenced significant differences when compared to the patient's AHI <5, AHI 5-15, and AHI >15 (p < 0.05). Furthermore, patients with an AHI >5 had longer hospital admissions, prolonged periods on mechanical ventilation, and a higher percentage of intubation rates. CONCLUSION: Apnea-Hypopnea Index and chronic obstructive pulmonary disease exacerbation are a frequent association found in patients with acute hypercapnic respiratory failure and COPD exacerbations that require NIV. This association could be a determining factor in the response to NIV, especially when AVAPS is used as a ventilatory strategy.

Chorioamnionitis as a risk factor for necrotizing enterocolitis: a systematic review and meta-analysis.

OBJECTIVE: To accumulate available evidence regarding the association between antenatal inflammation and necrotizing enterocolitis (NEC). STUDY DESIGN: A systematic literature search was performed using Medline, Embase, Cochrane Library, ISI Web of Knowledge, and reference hand searches. Human studies published in English that reported associations between chorioamnionitis or other indicators of antenatal inflammation and NEC were eligible. Relevant associations were extracted and reported. Studies reporting associations between histological chorioamnionitis (HC) and NEC, HC with fetal involvement and NEC, and clinical chorioamnionitis and NEC were pooled in separate meta-analyses. RESULTS: A total of 33 relevant studies were identified. Clinical chorioamnionitis was significantly associated with NEC (12 studies; n = 22 601; OR, 1.24; 95% CI, 1.01-1.52; P = .04; I(2) = 12%), but the association between HC and NEC was not statistically significant (13 studies; n = 5889; OR, 1.39; 95% CI, 0.95-2.04; P = .09; I(2) = 49%). However, HC with fetal involvement was highly associated with NEC (3 studies; n = 1640; OR, 3.29; 95% CI, 1.87-5.78; P ≤ .0001; I(2) = 10%). Selection based on study quality did not affect the results. No indications of publication bias were apparent. Multivariate analyses in single studies generally attenuated the reported associations. Several associations between other markers of antenatal inflammation and NEC are reported. CONCLUSION: Currently available evidence supports a role for antenatal inflammation in NEC pathophysiology. This finding emphasizes the need to further study the underlying mechanisms and evaluate potential interventions to improve postnatal intestinal outcomes.

Surfactant phosphatidylcholine pool size in human neonates with congenital diaphragmatic hernia requiring ECMO.

OBJECTIVE: We measured surfactant phosphatidylcholine (PC) pool size and half-life in human congenital diaphragmatic hernia (CDH) patients who required extracorporeal membrane oxygenation (ECMO). Study design Surfactant PC pool size and half-life were measured by endotracheal administration of deuterium-labeled dipalmitoylphosphatidylcholine in 8 neonates with CDH on ECMO (CDH-ECMO), in 7 neonates with meconium aspiration syndrome on ECMO (MAS-ECMO), and in 6 ventilated infants (NON-ECMO). RESULTS: Lung PC pool size in the CDH-ECMO group was 73 +/- 17 mg/kg (mean +/- SEM), which was not significantly different from the MAS-ECMO (50 +/- 18 mg/kg) and the NON-ECMO group (69 +/- 38 mg/kg). Surfactant PC concentration in tracheal aspirates was not different between groups (~6 mg/mL). However, the percentage of palmitic acid in surfactant PC was significantly lower in the MAS-ECMO (56.3%) and the NON-ECMO (55.8%) group compared with the CDH-ECMO (67.6%) group. Surfactant PC half-life (~24 hours) was not different between the groups. A correlation was found between the surfactant PC half-life and the duration of ECMO. CONCLUSIONS: These data show no decreased surfactant PC pool size in high risk CDH patients who require ECMO. A shorter half-life of surfactant PC, indicating a faster turnover, may result in a faster improvement of the pulmonary condition during ECMO.