Dataset Information

Respiratory Physiology of Prone Positioning With and Without Inhaled Nitric Oxide Across the Coronavirus Disease 2019 Acute Respiratory Distress Syndrome Severity Spectrum.

ABSTRACT:

Importance

Prone positioning improves clinical outcomes in moderate-to-severe acute respiratory distress syndrome and has been widely adopted for the treatment of patients with acute respiratory distress syndrome due to coronavirus disease 2019. Little is known about the effects of prone positioning among patients with less severe acute respiratory distress syndrome, obesity, or those treated with pulmonary vasodilators.

Objectives

We characterize the change in oxygenation, respiratory system compliance, and dead-space-to-tidal-volume ratio in response to prone positioning in patients with coronavirus disease 2019 acute respiratory distress syndrome with a range of severities. A subset analysis of patients treated with inhaled nitric oxide and subsequent prone positioning explored the influence of pulmonary vasodilation on the physiology of prone positioning.

Design setting and participants

Retrospective cohort study of all consecutively admitted adult patients with acute respiratory distress syndrome due to coronavirus disease 2019 treated with mechanical ventilation and prone positioning in the ICUs of an academic hospital between March 11, 2020, and May 1, 2020.

Main outcomes and measures

Respiratory system mechanics and gas exchange during the first episode of prone positioning.

Results

Among 122 patients, median (interquartile range) age was 60 years (51-71 yr), median body mass index was 31.5 kg/m² (27-35 kg/m²), and 50 patients (41%) were female. The ratio of Pao₂ to Fio₂ improved with prone positioning in 90% of patients. Prone positioning was associated with a significant increase in the ratio of Pao₂ to Fio₂ (from median 149 [123-170] to 226 [169-268], p < 0.001) but no change in dead-space-to-tidal-volume ratio or respiratory system compliance. Supine ratio of Pao₂ to Fio₂, respiratory system compliance, positive end-expiratory pressure, and body mass index did not correlate with absolute change in the ratio of Pao₂ to Fio₂ with prone positioning. However, patients with ratio of Pao₂ to Fio₂ less than 150 experienced a greater relative improvement in oxygenation with prone positioning than patients with ratio of Pao₂ to Fio₂ greater than or equal to 150 (median percent change in ratio of Pao₂ to Fio₂ 62 [29-107] vs 30 [10-70], p = 0.002). Among 12 patients, inhaled nitric oxide prior to prone positioning was associated with a significant increase in the ratio of Pao₂ to Fio₂ (from median 136 [77-168] to 170 [138-213], p = 0.003) and decrease in dead-space-to-tidal-volume ratio (0.54 [0.49-0.58] to 0.46 [0.44-0.53], p = 0.001). Subsequent prone positioning in this subgroup further improved the ratio of Pao₂ to Fio₂ (from 145 [122-183] to 205 [150-232], p = 0.017) but did not change dead-space-to-tidal-volume ratio.

Conclusions and relevance

Prone positioning improves oxygenation across the acute respiratory distress syndrome severity spectrum, irrespective of supine respiratory system compliance, positive end-expiratory pressure, or body mass index. There was a greater relative benefit among patients with more severe disease. Prone positioning confers an additive benefit in oxygenation among patients treated with inhaled nitric oxide.

SUBMITTER: Ziehr DR

PROVIDER: S-EPMC8208401 | biostudies-literature |

REPOSITORIES: biostudies-literature

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Project description:BackgroundIn the treatment for severe acute respiratory distress syndrome (ARDS) from coronavirus disease 2019 (COVID-19), the World Health Organization (WHO) recommends prone positioning (PP) during mechanical ventilation for periods of 12-16 h/d to potentially improve oxygenation and survival. In this prospective observational study, we evaluated the ability of long PP sessions to improve oxygenation in awake intensive care unit (ICU) patients with moderate or severe ARDS due to COVID-19.MethodsThe study was approved by the ethics committee of Galicia (code No. 2020-188), and all patients provided informed consent. In this case series, awake patients with moderate or severe ARDS by COVID-19 admitted to the ICU at University Hospital of Santiago from March 21 to April 5, 2020 were prospectively analyzed. Patients were instructed to remain in PP as long as possible until the patient felt too tired to maintain that position. Light sedation was administered with dexmedetomidine. The following information was collected: number and duration of PP sessions; tissue O2 saturation (StO2) and blood gases before, during, and following a PP session; need of mechanical ventilation; duration of ICU admission; and ICU outcome. Linear mixed-effects models (LMM) were fit to estimate changes from baseline with a random effect for patient.ResultsSeven patients with moderate or severe ARDS by COVID-19 were included. All patients received at least 1 PP session. A total of 16 PP sessions were performed in the 7 patients during the period study. The median duration of PP sessions was 10 hours. Dexmedetomidine was used in all PP sessions. Oxygenation increased in all 16 sessions performed in the 7 patients. The ratio of arterial oxygen partial pressure to fractional inspired oxygen (PaO2/FIO2) significantly increased during PP (change from baseline 110 with 97.5% confidence interval [CI], 19-202) and, after PP, albeit not significantly (change from baseline 38 with 97.5% CI, -9.2 to 85) compared with previous supine position. Similarly, tissue oxygenation underwent a small improvement during PP (change from baseline 2.6% with 97.5% CI, 0.69-4.6) without significant changes after PP. Two patients required intubation. All patients were discharged from the ICU.ConclusionsWe found that PP improved oxygenation in ICU patients with COVID-19 and moderate or severe ARDS. PP was relatively well tolerated in our patients and may be a simple strategy to improve oxygenation trying to reduce the number of patients in mechanical ventilation and the length of stay in the ICU, especially in COVID-19 pandemic.

Project description:ObjectivesTherapies for patients with respiratory failure from coronavirus disease 2019 are urgently needed. Early implementation of prone positioning ventilation improves survival in patients with acute respiratory distress syndrome, but studies examining the effect of proning on survival in patients with coronavirus disease 2019 are lacking. Our objective was to estimate the effect of early proning initiation on survival in patients with coronavirus disease 2019-associated respiratory failure.DesignData were derived from the Study of the Treatment and Outcomes in Critically Ill Patients with coronavirus disease 2019, a multicenter cohort study of critically ill adults with coronavirus disease 2019 admitted to 68 U.S. hospitals. Using these data, we emulated a target trial of prone positioning ventilation by categorizing mechanically ventilated hypoxemic (ratio of Pao2 over the corresponding Fio2 ≤ 200 mm Hg) patients as having been initiated on proning or not within 2 days of ICU admission. We fit an inverse probability-weighted Cox model to estimate the mortality hazard ratio for early proning versus no early proning. Patients were followed until death, hospital discharge, or end of follow-up.SettingICUs at 68 U.S. sites.PatientsCritically ill adults with laboratory-confirmed coronavirus disease 2019 receiving invasive mechanical ventilation with ratio of Pao2 over the corresponding Fio2 less than or equal to 200 mm Hg.InterventionsNone.Measurements and main resultsAmong 2,338 eligible patients, 702 (30.0%) were proned within the first 2 days of ICU admission. After inverse probability weighting, baseline and severity of illness characteristics were well-balanced between groups. A total of 1,017 (43.5%) of the 2,338 patients were discharged alive, 1,101 (47.1%) died, and 220 (9.4%) were still hospitalized at last follow-up. Patients proned within the first 2 days of ICU admission had a lower adjusted risk of death compared with nonproned patients (hazard ratio, 0.84; 95% CI, 0.73-0.97).ConclusionsIn-hospital mortality was lower in mechanically ventilated hypoxemic patients with coronavirus disease 2019 treated with early proning compared with patients whose treatment did not include early proning.

Project description:Use of prone positioning in patients with acute respiratory distress syndrome (ARDS) from COVID-19 may be greater than in patients treated for ARDS before the pandemic. However, the magnitude of this increase, sources of practice variation, and the extent to which use adheres to guidelines is unknown.ObjectivesTo compare prone positioning practices in patients with COVID-19 ARDS versus ARDS treated before the pandemic.Design setting and participantsWe conducted a multicenter retrospective cohort study of mechanically ventilated patients with early moderate-to-severe ARDS from COVID-19 (2020-2021) or ARDS from non-COVID-19 pneumonia (2018-2019) across 19 ICUs at five hospitals in Maryland.Main outcomes and measuresThe primary outcome was initiation of prolonged prone positioning (≥ 16 hr) within 48 hours of meeting oxygenation criteria. Comparisons were made between cohorts and within subgroups including academic versus community hospitals, and medical versus nonmedical ICUs. Other outcomes of interest included time to proning initiation, duration of prone sessions and temporal trends in proning frequency.ResultsProning was initiated within 48 hours in 227 of 389 patients (58.4%) with COVID-19 and 11 of 123 patients (8.9%) with historic ARDS (49.4% absolute increase [95% CI for % increase, 41.7-57.1%]). Comparing COVID-19 to historic ARDS, increases in proning were similar in academic and community settings but were larger in medical versus nonmedical ICUs. Proning was initiated earlier in COVID-19 versus historic ARDS (median hours (hr) from oxygenation criteria, 12.9 vs 30.6; p = 0.002) and proning sessions were longer (median hr, 43.0 vs 28.0; p = 0.01). Proning frequency increased rapidly at the beginning of the pandemic and was sustained.Conclusions and relevanceWe observed greater overall use of prone positioning, along with shorter time to initiation and longer proning sessions in ARDS from COVID-19 versus historic ARDS. This rapid practice change can serve as a model for implementing evidence-based practices in critical care.

Project description:Given perceived similarities between coronavirus disease 2019 pneumonia and the acute respiratory distress syndrome, we explored whether awake self-proning improved outcomes in coronavirus disease 2019-infected patients treated in a rural medical center with limited resources during a significant local coronavirus disease 2019 outbreak.DesignRetrospective analysis of prospectively collected clinical data.SettingSingle-center rural community-based medical center in Grand Island, NE.PatientsOne hundred five nonintubated, coronavirus disease-infected patients.InterventionsNone.Measurements and main resultsAfter patients were educated on the benefits of awake self-proning, compliance was voluntary. The primary outcome was need for intubation during the hospital stay; secondary outcomes included serial peripheral capillary oxygen saturation measured by pulse oximetry to the Fio2 ratios, in-hospital mortality, and discharge disposition. Of 105 nonintubated, coronavirus disease-infected patients, 40 tolerated awake self-proning. Patients who were able to prone were younger and had lower disease severity. The risk of intubation was lower in proned patients after adjusting for disease severity using Sequential Organ Failure Assessment scores (adjusted hazard ratio, 0.30; 95% CI, 0.09-0.96; p = 0.043) or Acute Physiology and Chronic Health Evaluation II scores (adjusted hazard ratio, 0.30; 95% CI, 0.10-0.91; p = 0.034). No prone patient died compared with 24.6% of patients who were not prone (p < 0.001; number needed to treat = 5; 95% CI, 3-8). The probability of being discharged alive and peripheral capillary oxygen saturation measured by pulse oximetry to the Fio2 ratios were statistically similar for both groups.ConclusionsAwake self-proning was associated with lower mortality and intubation rates in coronavirus disease 2019-infected patients. Prone positioning appears to be a safe and inexpensive strategy to improve outcomes and spare limited resources. Prospective efforts are needed to better delineate the effect of awake proning on oxygenation and to improve patients' ability to tolerate this intervention.

Project description:ObjectivesThe study investigated the impact of prone positioning during venovenous extracorporeal membrane oxygenation support for coronavirus disease 2019 acute respiratory failure on the patient outcome.DesignAn observational study of venovenous extracorporeal membrane oxygenation patients. We used a multistate survival model to compare the outcomes of patients treated with or without prone positioning during extracorporeal membrane oxygenation, which incorporates the dynamic nature of prone positioning and adjusts for potential confounders.SettingSeventy-two international institutions participating in the Coronavirus Disease 2019 Critical Care Consortium international registry.PatientsCoronavirus disease 2019 patients who were supported by venovenous extracorporeal membrane oxygenation during the study period.InterventionNone.Measurements and main resultsThere were 232 coronavirus disease 2019 patients at 72 participating institutions who were supported with venovenous extracorporeal membrane oxygenation during the study period from February 16, 2020, to October 31, 2020. Proning was used in 176 patients (76%) before initiation of extracorporeal membrane oxygenation and in 67 patients (29%) during extracorporeal membrane oxygenation. Survival to hospital discharge was 33% in the extracorporeal membrane oxygenation prone group versus 22% in the extracorporeal membrane oxygenation supine group. Prone positioning during extracorporeal membrane oxygenation support was associated with reduced mortality (hazard ratio, 0.31; 95% CI, 0.14-0.68).ConclusionsOur study highlights that prone positioning during venovenous extracorporeal membrane oxygenation support for refractory coronavirus disease 2019-related acute respiratory distress syndrome is associated with reduced mortality. Given the observational nature of the study, a randomized controlled trial of prone positioning on venovenous extracorporeal membrane oxygenation is needed to confirm these findings.