The impact of frailty on survival times up to one year among patients admitted to ICU with in-hospital cardiac arrest.

BACKGROUND: In-hospital cardiac arrest (IHCA) is a serious medical emergency. When IHCA occurs in patients with frailty, short-term survival is poor. However, the impact of frailty on long-term survival is unknown. METHODS: We performed a retrospective multicentre study of all critically ill adult (age ≥ 16 years) patients admitted to Australian intensive care units (ICU) between 1st January 2018 to 31st March 2022. We included all patients who had an IHCA within the 24 h before ICU admission with a documented Clinical Frail Scale (CFS). The primary outcome was median survival up to one year following ICU admission. The effect of frailty on one-year survival was assessed using a Cox proportional hazards model, adjusting for age, sex, comorbidities, sequential organ failure assessment (SOFA) score, and hospital type. RESULTS: We examined 3769 patients, of whom 30.8% (n = 1160) were frail (CFS ≥ 5). The median survival was significantly shorter for patients with frailty (median [IQR] days 19 [1-365] vs 302 [9-365]; p < 0.001). The overall one-year mortality was worse for the patients with frailty when compared to the non-frail group (64.8% [95%CI 61.9-67.5] vs 36.4% [95%CI 34.5-38.3], p < 0.001). Each unit increment in the CFS was associated with 22% worse survival outcome (adjusted Hazard ratio = 1.22, 95%-CI 1.19-1.26), after adjustment for confounders. The survival trend was similar among patients who survived the hospitalization. CONCLUSION: In this retrospective multicentre study, frailty was associated with poorer one-year survival in patients admitted to Australian ICUs following an IHCA.

Respiratory system mechanics, gas exchange, and outcomes in mechanically ventilated patients with COVID-19-related acute respiratory distress syndrome: a systematic review and meta-analysis.

The association of respiratory mechanics, particularly respiratory system static compliance (CRS), with severity of hypoxaemia in patients with COVID-19-related acute respiratory distress syndrome (ARDS) has been widely debated, with some studies reporting distinct ARDS phenotypes based on CRS. Ascertaining whether such phenotypes exist is important, because they might indicate the need for ventilation strategies that differ from those used in patients with ARDS due to other causes. In a systematic review and meta-analysis of studies published between Dec 1, 2019, and March 14, 2022, we evaluated respiratory system mechanics, ventilator parameters, gas exchange parameters, and clinical outcomes in patients with COVID-19-related ARDS. Among 11 356 patients in 37 studies, mean reported CRS, measured close to the time of endotracheal intubation, was 35·8 mL/cm H2O (95% CI 33·9-37·8; I2=96·9%, τ2=32·6). Pooled mean CRS was normally distributed. Increasing ARDS severity (assessed by PaO2/FiO2 ratio as mild, moderate, or severe) was associated with decreasing CRS. We found no evidence for distinct CRS-based clinical phenotypes in patients with COVID-19-related ARDS, and we therefore conclude that no change in conventional lung-protective ventilation strategies is warranted. Future studies should explore the personalisation of mechanical ventilation strategies according to factors including respiratory system mechanics and haemodynamic status in patients with ARDS.

Pressure support ventilation in intensive care patients receiving prolonged invasive ventilation.

Background: To our knowledge, the use and management of pressure support ventilation (PSV) in patients receiving prolonged (≥ 7 days) invasive mechanical ventilation has not previously been described. Objective: To collect and analyse data on the use and management of PSV in critically ill patients receiving prolonged ventilation. Design, setting and participants: We performed a multicentre retrospective observational study in Australia, with a focus on PSV in patients ventilated for ≥ 7 days. Main outcome measures: We obtained detailed data on ventilator management twice daily (8am and 8pm moments) for the first 7 days of ventilation. Results: Among 143 consecutive patients, 90/142 (63.4%) had received PSV by Day 7, and PSV accounted for 40.5% (784/1935) of ventilation moments. The most common pressure support level was 10 cmH2O (352/780) observations [45.1%]) with little variation over time, and 37 of 114 patients (32.4%) had no change in pressure support. Mean tidal volume during PSV was 8.3 (7.0-9.5) mL/kg predicted bodyweight (PBW) compared with 7.5 (7.0-8.3) mL/kg PBW during mandatory ventilation (P < 0.001). For 74.6% (247/331) of moments, despite a tidal volume of more than 8 mL/kg PBW, the pressure support level was not changed. Among 122 patients exposed to PSV, 97 (79.5%) received likely over-assistance according to rapid shallow breathing index criteria. Of 784 PSV moments, 411 (52.4%) were also likely over-assisted according to rapid shallow breathing index criteria, and 269/346 (77.7%) having no subsequent adjustment of pressure support. Conclusions: In patients receiving prolonged ventilation, almost two-thirds received PSV, which accounted for 40.5% of mechanical ventilation time. Half of the PSV-treated patients were exposed to high tidal volume and two-thirds to likely over-assistance. These observations provide evidence that can be used to inform interventional studies of PSV management.