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.

Case Fatality Rates for Patients with COVID-19 Requiring Invasive Mechanical Ventilation. A Meta-analysis.

Rationale: Initial reports of case fatality rates (CFRs) among adults with coronavirus disease (COVID-19) receiving invasive mechanical ventilation (IMV) are highly variable.Objectives: To examine the CFR of patients with COVID-19 receiving IMV.Methods: Two authors independently searched PubMed, Embase, medRxiv, bioRxiv, the COVID-19 living systematic review, and national registry databases. The primary outcome was the "reported CFR" for patients with confirmed COVID-19 requiring IMV. "Definitive hospital CFR" for patients with outcomes at hospital discharge was also investigated. Finally, CFR was analyzed by patient age, geographic region, and study quality on the basis of the Newcastle-Ottawa Scale.Measurements and Results: Sixty-nine studies were included, describing 57,420 adult patients with COVID-19 who received IMV. Overall reported CFR was estimated as 45% (95% confidence interval [CI], 39-52%). Fifty-four of 69 studies stated whether hospital outcomes were available but provided a definitive hospital outcome on only 13,120 (22.8%) of the total IMV patient population. Among studies in which age-stratified CFR was available, pooled CFR estimates ranged from 47.9% (95% CI, 46.4-49.4%) in younger patients (age ≤40 yr) to 84.4% (95% CI, 83.3-85.4%) in older patients (age >80 yr). CFR was also higher in early COVID-19 epicenters. Overall heterogeneity is high (I2 >90%), with nonsignificant Egger's regression test suggesting no publication bias.Conclusions: Almost half of patients with COVID-19 receiving IMV died based on the reported CFR, but variable CFR reporting methods resulted in a wide range of CFRs between studies. The reported CFR was higher in older patients and in early pandemic epicenters, which may be influenced by limited ICU resources. Reporting of definitive outcomes on all patients would facilitate comparisons between studies.Systematic review registered with PROSPERO (CRD42020186997).

Haemodynamic effect of a 20% albumin fluid bolus in post-cardiac surgery patients.

OBJECTIVE: To study the cardiovascular effect over 30 minutes following the end of fluid bolus therapy (FBT) with 20% albumin in patients after cardiac surgery. DESIGN: Prospective observational study. SETTING: Intensive care unit of a tertiary university-affiliated hospital. PARTICIPANTS: Twenty post-cardiac surgery mechanically ventilated patients with a clinical decision to administer FBT. INTERVENTION: FBT with a 100 mL bolus of 20% albumin. MAIN OUTCOME MEASURES: Cardiac index (CI) response was defined by a ≥ 15% increase, while mean arterial pressure (MAP) response was defined by a ≥ 10% increase. RESULTS: The most common indication for FBT was hypotension (40%). Median duration of infusion was 7 minutes (interquartile range [IQR], 3-9 min). At the end of FBT, five patients (25%) showed a CI response, which increased to almost half in the following 30 minutes and dissipated in one patient. MAP response occurred in 11 patients (55%) and dissipated in five patients (45%) by a median of 6 minutes (IQR, 6-10 min). CI and MAP responses coexisted in four patients (20%). An intrabolus MAP response occurred in 17 patients (85%) but dissipated in 11 patients (65%) within a median of 7 minutes (IQR, 2-11 min). On regression analysis, faster fluid bolus administration predicted MAP increase at the end of the bolus. CONCLUSION: In post-cardiac surgery patients, CI response to 20% albumin FBT was not congruous with MAP response over 30 minutes. Although hypotension was the main indication for FBT and a MAP response occurred in most of patients, such response was maximal during the bolus, dissipated in a few minutes, and was dissociated from the CI response.

Characteristics, incidence, and outcome of patients admitted to the intensive care unit with myasthenia gravis.

BACKGROUND: There are limited data on the characteristics, incidence, and mortality of patients with myasthenia gravis (MG) admitted to the ICU. AIMS: To study the epidemiology, characteristics and outcome of patients with MG in Australian and New Zealand (ANZ) ICUs over a decade. METHODS: We performed a retrospective observational, cross sectional study of data from the Australian and New Zealand Intensive Care Society (ANZICS) Adult Patient Database (APD). We collected data on all adult patients admitted with a primary diagnosis of MG to 159 Australian and 19 New Zealand ICUs between January 1, 2005 and December 31, 2015.We extracted detailed relevant data and performed statistical assessment. RESULTS: We identified 245 patients admitted to ICU with the primary diagnosis of MG, with an incidence increasing from 1 to 2.5 per thousand ICU admissions (P<0.0001) and from 1 to 2.2 per million people (P=0.02). Mean age was 60years with more patients being female (53.7% vs 47.3%) and 91 (37.1%) patients received mechanical ventilation. Hospital mortality occurred in 13 (5.3%) patients with a mortality rate lower than in other ICU patients. CONCLUSIONS: In ANZ, the ICU and population incidence of MG has increased over the last decade. However, its mortality rate was low.

Auditing an intensive care unit recycling program.

BACKGROUND: The provision of health care has significant direct environmental effects such as energy and water use and waste production, and indirect effects, including manufacturing and transport of drugs and equipment. Recycling of hospital waste is one strategy to reduce waste disposed of as landfill, preserve resources, reduce greenhouse gas emissions, and potentially remain fiscally responsible. We began an intensive care unit recycling program, because a significant proportion of ICU waste was known to be recyclable. OBJECTIVES: To determine the weight and proportion of ICU waste recycled, the proportion of incorrect waste disposal (including infectious waste contamination), the opportunity for further recycling and the financial effects of the recycling program. METHODS: We weighed all waste and recyclables from an 11-bed ICU in an Australian metropolitan hospital for 7 non-consecutive days. As part of routine care, ICU waste was separated into general, infectious and recycling streams. Recycling streams were paper and cardboard, three plastics streams (polypropylene, mixed plastics and polyvinylchloride [PVC]) and commingled waste (steel, aluminium and some plastics). ICU waste from the waste and recycling bins was sorted into those five recycling streams, general waste and infectious waste. After sorting, the waste was weighed and examined. Recycling was classified as achieved (actual), potential and total. Potential recycling was defined as being acceptable to hospital protocol and local recycling programs. Direct and indirect financial costs, excluding labour, were examined. RESULTS: During the 7-day period, the total ICU waste was 505 kg: general waste, 222 kg (44%); infectious waste, 138 kg (27%); potentially recyclable waste, 145 kg (28%). Of the potentially recyclable waste, 70 kg (49%) was actually recycled (14% of the total ICU waste). In the infectious waste bins, 82% was truly infectious. There was no infectious contamination of the recycling streams. The PVC waste was 37% contaminated (primarily by other plastics), but there was less than 1% contamination of other recycling streams. The estimated cost of the recycling program was about an additional $1000/year. CONCLUSION: In our 11-bed ICU, we recycled 14% of the total waste produced over 7-days, which was nearly half of the potentially recyclable waste. There was no infectious contamination of recyclables and minimal contamination with other waste streams, except for the PVC plastic. The estimated annual cost of the recycling program was $1000, reflecting the greater cost of disposal of some recyclables (paper and cardboard v most plastic types).