Noninvasive ventilation for acute respiratory failure: the next step is to know when to stop

Long-term survival of mechanically ventilated patients with severe COVID-19: an observational cohort study

Background

Information is lacking regarding long-term survival and predictive factors for mortality in patients with acute hypoxemic respiratory failure due to coronavirus disease 2019 (COVID-19) and undergoing invasive mechanical ventilation. We aimed to estimate 180-day mortality of patients with COVID-19 requiring invasive ventilation, and to develop a predictive model for long-term mortality.

Methods

Retrospective, multicentre, national cohort study between March 8 and April 30, 2020 in 16 intensive care units (ICU) in Spain. Participants were consecutive adults who received invasive mechanical ventilation for COVID-19. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection detected in positive testing of a nasopharyngeal sample and confirmed by real time reverse-transcriptase polymerase chain reaction (rt-PCR). The primary outcomes was 180-day survival after hospital admission. Secondary outcomes were length of ICU and hospital stay, and ICU and in-hospital mortality. A predictive model was developed to estimate the probability of 180-day mortality.

Results

868 patients were included (median age, 64 years [interquartile range [IQR], 56–71 years]; 72% male). Severity at ICU admission, estimated by SAPS3, was 56 points [IQR 50–63]. Prior to intubation, 26% received some type of noninvasive respiratory support. The unadjusted overall 180-day survival rates was 59% (95% CI 56–62%). The predictive factors measured during ICU stay, and associated with 180-day mortality were: age [Odds Ratio [OR] per 1-year increase 1.051, 95% CI 1.033–1.068)), SAPS3 (OR per 1-point increase 1.027, 95% CI 1.011–1.044), diabetes (OR 1.546, 95% CI 1.085–2.204), neutrophils to lymphocytes ratio (OR per 1-unit increase 1.008, 95% CI 1.001–1.016), failed attempt of noninvasive positive pressure ventilation prior to orotracheal intubation (OR 1.878 (95% CI 1.124–3.140), use of selective digestive decontamination strategy during ICU stay (OR 0.590 (95% CI 0.358–0.972) and administration of low dosage of corticosteroids (methylprednisolone 1 mg/kg) (OR 2.042 (95% CI 1.205–3.460).

Conclusion

The long-term survival of mechanically ventilated patients with severe COVID-19 reaches more than 50% and may help to provide individualized risk stratification and potential treatments.

Trial registration: ClinicalTrials.gov Identifier: NCT04379258. Registered 10 April 2020 (retrospectively registered)

Supplementary Information

The online version contains supplementary material available at 10.1186/s13613-021-00929-y.

Factors associated with non-invasive mechanical ventilation failure in patients with hematological neoplasia and their association with outcomes

Background

The usefulness of non-invasive mechanical ventilation (NIMV) in oncohematological patients is still a matter of debate.

Aim

To analyze the rate of noninvasive ventilation failure and the main characteristics associated with this endpoint in oncohematological patients with acute respiratory failure (ARF).

Methods

A ventilatory support protocol was developed and implemented before the onset of the study. According to the PaO₂/FiO₂ (P/F) ratio and clinical judgment, patients received supplementary oxygen therapy, NIMV, or invasive mechanical ventilation (IMV).

Results

Eighty-two patients were included, average age between 52.1 ± 16 years old; 44 (53.6%) were male. The tested protocol was followed in 95.1% of cases. Six patients (7.3%) received IMV, 59 (89.7%) received NIMV, and 17 (20.7%) received oxygen therapy. ICU mortality rates were significantly higher in the IMV (83.3%) than in the NIMV (49.2%) and oxygen therapy (5.9%) groups (P < 0.001). Among the 59 patients who initially received NIMV, 30 (50.8%) had to eventually be intubated. Higher SOFA score at baseline (1.35 [95% CI = 1.12-2.10], P = 0.007), higher respiratory rate (RR) (1.10 [95% CI = 1.00-1.22], P = 0.048), and sepsis on admission (16.9 [95% CI = 1.93-149.26], P = 0.011) were independently associated with the need of orotracheal intubation among patients initially treated with NIMV. Moreover, NIMV failure was independently associated with ICU (P < 0.001) and hospital mortality (P = 0.049), and mortality between 6 months and 1 year (P < 0.001).

Conclusion

The implementation of a NIMV protocol is feasible in patients with hematological neoplasia admitted to the ICU, even though its benefits still remain to be demonstrated. NIMV failure was associated with higher SOFA and RR and more frequent sepsis, and it was also related to poor prognosis.

Noninvasive Ventilation for Critically Ill Subjects With Acute Respiratory Failure in the Emergency Department

BACKGROUND

We aimed to investigate the association between noninvasive ventilation (NIV) initiated in the emergency department and patient outcomes for those requiring invasive mechanical ventilation so that we could understand the effect of extended NIV use (ie, > 4 h) prior to invasive mechanical ventilation on patient outcomes.

METHODS

We conducted a retrospective single-center cohort study at an academic tertiary care hospital center. All emergency department patients with acute respiratory failure requiring invasive mechanical ventilation and admission to the ICU within 48 h of initial presentation over a 24-month period were included.

RESULTS

Subject characteristics, ventilator parameters, and clinical course were captured via electronic query, respiratory billing data, and standardized chart abstraction. A total of 431 subjects with acute respiratory failure requiring invasive mechanical ventilation within 48 h of arrival were identified, of whom 115 (26.7%) were exposed to NIV prior to invasive mechanical ventilation, with a median duration of 4 h (interquartile range 1.9-9.3). Based on a multivariable model controlling for covariates, any NIV exposure prior to invasive mechanical ventilation was not associated with an increased odds of persistent organ dysfunction or death. However, in the subset of subjects exposed to NIV, extended NIV use (ie, > 4 h) prior to invasive mechanical ventilation was associated with increased odds of persistent organ dysfunction or death (odds ratio 4.11, 95% CI 1.51-11.19). Extended NIV use was also associated with increased odds of in-hospital mortality (odds ratio 4.02, 95% CI 1.51-10.74).

CONCLUSIONS

Although any exposure to NIV prior to invasive mechanical ventilation did not appear to affect morbidity and mortality, extended NIV use prior to invasive mechanical ventilation was associated with worse patient outcomes, suggesting a need for additional study to better understand the ramifications of duration of NIV use prior to failure on outcomes. Given this early timeframe for intervention, future studies should be collaborations between the emergency department and ICU.