Premature monochorionic monoamniotic twins have lower lung compliance at birth than matched dichorionic diamniotic twins

BACKGROUND: Premature infants are born with immature lungs that demonstrate abnormal pulmonary function with differences in passive respiratory system compliance and resistance, and functional residual capacity. To our knowledge, no studies have evaluated differences in neonatal pulmonary function based on the type of twin gestation, or chorionicity. Given the effect of chorionicity on outcomes, we aimed to study the effect of twin type, monochorionic monoamniotic (MCMA) vs dichorionic diamniotic (DCDA), on neonatal early pulmonary function tests. METHODS: In this prospective cohort study, 5 sets of DCDA twins were matched to 5 sets of MCMA twins on gestational age at delivery, latency from antenatal corticosteroid exposure, birthweight, race and gender. Mean values were compared for passive respiratory system compliance and resistance, functional residual capacity, and tidal volume. RESULTS: MCMA infants had a significantly lower compliance (0.64 vs 1.25 mL/cm H2O /kg; p = 0.0001) and significantly higher resistance (0.130 vs 0.087 cm H2O /mL/sec; p = 0.0003) than DCDA infants. Functional residual capacity was lower for MCMA than DCDA infants (17.5 vs 23.4 mL/kg; p = 0.17). Further, 80% of MCMA infants required intubation for surfactant administration compared to 20% of DCDA infants, indicating the clinical significance of these objective measures. CONCLUSIONS: Due to the matched case-control design, causality cannot be established. However, we speculate that these differences in lung function may derive from differential exposure to preterm labor and endogenous maternal corticosteroid exposure. Further study is necessary to establish the true causal relationship.

Efficacy and Safety of Dapagliflozin in Patients With Inadequately Controlled Type 1 Diabetes (the DEPICT-2 Study): 24-Week Results From a Randomized Controlled Trial

OBJECTIVE

This 24-week, double-blinded, phase 3 clinical trial (DEPICT-2; ClinicalTrials.gov, NCT02460978) evaluated efficacy and safety of dapagliflozin as adjunct therapy to adjustable insulin in patients with inadequately controlled type 1 diabetes (HbA_1c 7.5-10.5%).

RESEARCH DESIGN AND METHODS

Patients were randomized 1:1:1 to dapagliflozin 5 mg (n = 271), dapagliflozin 10 mg (n = 270), or placebo (n = 272) plus insulin. Insulin dose was adjusted by investigators according to self-monitored glucose readings, local guidance, and individual circumstances.

RESULTS

Baseline characteristics were balanced between treatment groups. At week 24, dapagliflozin significantly decreased HbA_1c (primary outcome; difference vs. placebo: dapagliflozin 5 mg -0.37% [95% CI -0.49, -0.26], dapagliflozin 10 mg -0.42% [-0.53, -0.30]), total daily insulin dose (-10.78% [-13.73, -7.72] and -11.08% [-14.04, -8.02], respectively), and body weight (-3.21% [-3.96, -2.45] and -3.74% [-4.49, -2.99], respectively) (P < 0.0001 for all). Mean interstitial glucose, amplitude of glucose excursion, and percent of readings within target glycemic range (>70 to ≤180 mg/dL) versus placebo were significantly improved. More patients receiving dapagliflozin achieved a reduction in HbA_1c ≥0.5% without severe hypoglycemia compared with placebo. Adverse events were reported for 72.7%, 67.0%, and 63.2% of patients receiving dapagliflozin 5 mg, dapagliflozin 10 mg, and placebo, respectively. Hypoglycemia, including severe hypoglycemia, was balanced between groups. There were more adjudicated definite diabetic ketoacidosis (DKA) events with dapagliflozin: 2.6%, 2.2%, and 0% for dapagliflozin 5 mg, dapagliflozin 10 mg, and placebo, respectively.

CONCLUSIONS

Dapagliflozin as adjunct therapy to adjustable insulin in patients with type 1 diabetes was well tolerated and improved glycemic control with no increase in hypoglycemia versus placebo but with more DKA events.

End-tidal carbon dioxide in critically ill patients during changes in mechanical ventilation

Values of end-tidal CO2 (PETCO2) approximate PaCO2 in spontaneous breathing normal subjects and in stable patients receiving mechanical ventilatory support (MVS). Because marked inequality of ventilation/perfusion ratios in critically ill patients might affect this correlation, we assessed changes of PETCO2 in predicting changes in PaCO2 (delta PaCO2) and changes in minute ventilation (delta Ve) in this patient population. Twenty consecutive intubated patients 38 to 89 yr of age (mean, 70 yr) with respiratory failure while receiving MVS with indwelling arterial lines were studied. Settings on the mechanical ventilator were varied for frequency and tidal volume, and after a minimum of 5 to 10 min equilibration, PaCO2 and PETCO2 were measured. Vt and Ve were recorded from the digital indicator of the pneumotachygraph within the mechanical ventilator and corrected for compression volume in the respirator circuit. A total of 116 simultaneous measurements were performed. PETCO2 correlated well with PaCO2 (r = 0.78, p less than 0.001). The 95% confidence interval for the mean difference in PaCO2-PETCO2 was 4.0 +/- 0.97 mm Hg. However, delta PETCO2 (measured from baseline) did not correlate as well with delta PaCO2 (r = 0.58, p = less than 0.001). In four patients, the trend in their PETCO2 during changes in mechanical ventilation were in the opposite direction from the trend in their PaCO2. Thus, many critically ill patients, who cannto be preidentified, have an inconstant PaCO2-PETCO2 gradient with changes of ventilation. Utilization of PETCO2 as a noninvasive monitoring substitute for trends in PaCO2 in critically ill patients may be misleading despite establishing an initial PaCO2-PETCO2 relationship.