A Retrospective Analysis of the Effects of Time on Compliance and Driving Pressures in ARDS.

BACKGROUND: The evolution of compliance and driving pressure in ARDS and the effects of time spent on noninvasive respiratory support prior to intubation have not been well studied. We conducted this study to assess the effect of the duration of noninvasive respiratory support prior to intubation (ie, noninvasive ventilation [NIV], high-flow nasal cannula [HFNC], or a combination of NIV and HFNC) on static compliance and driving pressure and retrospectively describe its trajectory over time for COVID-19 and non-COVID-19 ARDS while on mechanical ventilation. METHODS: This is a retrospective analysis of prospectively collected data from one university-affiliated academic medical center, one rural magnet hospital, and 3 suburban community facilities. A total of 589 subjects were included: 55 COVID-19 positive, 137 culture positive, and 397 culture-negative subjects. Static compliance and driving pressure were calculated at each 8-h subject-ventilator assessment. RESULTS: Days of pre-intubation noninvasive respiratory support were associated with worse compliance and driving pressure but did not moderate any trajectory. COVID-19-positive subjects showed non-statistically significant worsening compliance by 0.08 units per subject-ventilator assessment (P = .24), whereas COVID-19-negative subjects who were either culture positive or negative showed statistically significant improvement (0.12 and 0.18, respectively; both P < .05); a statistically similar but inverse pattern was observed for driving pressure. CONCLUSIONS: In contrast to non-COVID-19 ARDS, COVID-19 ARDS was associated with a more ominous trajectory with no improvement in static compliance or driving pressures. Though there was no association between days of pre-intubation noninvasive respiratory support and mortality, its use was associated with worse overall compliance and driving pressure.

Sepsis, the Administration of IV Fluids, and Respiratory Failure: A Retrospective Analysis-SAIFR Study.

BACKGROUND: Although resuscitation with IV fluids is the cornerstone of sepsis management, consensus regarding their association with improvement in clinical outcomes is lacking. RESEARCH QUESTION: Is there a difference in the incidence of respiratory failure in patients with sepsis who received guideline-recommended initial IV fluid bolus of 30 mL/kg or more conservative resuscitation of less than 30 mL/kg? STUDY DESIGN AND METHODS: This was a retrospective analysis of prospectively collected clinical data conducted at an academic medical center in Omaha, Nebraska. We abstracted data from 214 patients with sepsis admitted to a single academic medical center between June 2017 and June 2018. Patients were stratified by receipt of guideline-recommended fluid bolus. The primary outcome was respiratory failure defined as an increase in oxygen flow rate or more intense oxygenation and ventilation support; oxygen requirement and volume were measured at admission, 6 h, 12 h, 24 h, and at discharge. Subgroup analyses were conducted in high-risk patients with congestive heart failure (CHF) as well as those with chronic kidney disease (CKD). RESULTS: A total of 62 patients (29.0%) received appropriate bolus treatment. The overall rate of respiratory failure was not statistically different between patients who received appropriate bolus or did not (40.3% vs 36.8%; P = .634). Likewise, no differences were observed in time to respiratory failure (P = .645) or risk of respiratory failure (adjusted hazard ratio, 1.1 [95% CI, 0.7-1.7]; P = .774). Results were similar within the high-risk CHF and CKD subgroups. INTERPRETATION: In this single-center retrospective study, we found that by broadly defining respiratory failure as an increase in oxygen requirements, a conservative initial IV fluid resuscitation strategy did not correlate with decreased rates of hypoxemic respiratory failure.