Hypoxaemic respiratory failure and awake prone ventilation (HYPER-AP) - Protocol for randomized, controlled clinical trial.

BACKGROUND: Awake prone positioning is studied extensively during Covid-19 pandemic, but there is very limited evidence on its utility in acute hypoxic respiratory failure caused by bacterial infections or other causes. The aim of our research is to evaluate the impact of awake prone positioning on outcomes in non-intubated adult patients with acute non-Covid19 hypoxemic respiratory failure. METHODS: This is a multi-center randomized controlled trial (RCT) with a parallel-group design and a 1:1 allocation ratio. Adult patients, admitted to ICU and diagnosed with hypoxemic respiratory failure will be randomly allocated into intervention (awake prone position (APP)) or control group. Our hypothesis is that addition of awake prone positioning to standard oxygen, high flow oxygen therapy and non-invasive ventilation may reduce the need for mechanical ventilation in adult patients diagnosed with acute hypoxemic respiratory failure. Primary outcome is rate of endotracheal intubation; secondary outcomes include intensive care and hospital mortality, duration of mechanical ventilation, length of intensive care and hospital stay and health related quality of life post hospital discharge. Primary and secondary outcomes will be assessed at hospital discharge, 30, 90 days and 1 year following randomisation. CONCLUSION: The Hyper-AP study will assess the superiority of awake prone positioning versus standard treatment in spontaneously breathing ICU patients diagnosed with hypoxaemic respiratory failure.

Determinants of Increased Effort of Breathing in Non-Intubated Critical COVID-19 Patients.

Background and objectives: Acute respiratory distress syndrome (ARDS) is the most common complication occurring in COVID-19 patients admitted to the ICU. Given the increased respiratory work of these patients, it is necessary to evaluate their actual breathing efforts. The aim of this study is to report the incidence and determinants of increased effort of breathing (EOB) in critical COVID-19 patients. Materials and Methods: This was a retrospective study of COVID-19 patients admitted to the ICU during the year of 2020. Respiratory rate (RR) was chosen as an indicator of EOB. The cut-off value was set at more than 20 breaths per minute. ROC-AUC analysis was performed to identify the accuracy of the PaO2 and PaCO2 to determine increased EOB. Furthermore, multivariate regression analysis was performed to reveal the determinants of increased EOB. Results: 213 patients were included in the study. Mean RR in the population was 24.20 ± 6.28. 138 (64.8%) of the patients had increased EOB. The ROC-AUC analysis revealed the PaO2 (0.656 (CI 95%: 0.579−0.734, p < 0.001) as more accurate predictor of EOB than PaCO2 (0.584 (CI 95%: 0.505−0.662, p = 0.043). In the final multivariate model, the SpO2 (exp(B) = 0.922, CI 95%: 0.874−0.97 p = 0.033), PaO2/FiO2 ratio (exp(B) = 0.996, CI 95%: 0.922−1.000, p = 0.003) and PaO2 (exp(B) = 0.989 CI 95%: 0.982−0.996 p = 0.003) prevailed as independent predictors of increased EOB. Conclusions: To conclude, PaO2 was revealed as a more accurate predictor of increased EOB than PaCO2. Further investigation revealed the independent determinants of EOB: blood oxygen saturation, PaO2 and PaO2/FiO2 ratio.

Acute Kidney Injury in Cardiac Surgery Patients: Role of Glomerular Filtration Rate and Fat-Free Mass.

SUMMARY BACKGROUND: eGFR (estimated glomerular filtration rate) formulas may be inaccurate in overweight cardiac surgery patients, overestimating the kidney reserve. The aim of this study was to modify the eGFR formulas and to determine whether the modified eGFR is a more accurate predictor of acute kidney injury (AKI). MATERIALS AND METHODS: The patients were assigned into 4 BMI groups as follows: normal weight (18.5- 25 kg/m2), pre-obesity (25-30 kg/m2), class I obese (30-35 kg/m2), class II and III obese (≥35 kg/m2). Cockcroft- Gault (CG) eGFR formula was modified by using the fat-free mass (FFM) derived from bioelectrical impedance. ROC-AUC curves were analyzed to identify the accuracy of the eGFR formulas (CG, CG modified with FFM, Mayo Clinic Quadratic equation, CKD-EPI, MDRD) to predict the AKI in each group. RESULTS: Although all of the used equations showed similar predictive power in the normal weight and overweight category, Mayo formula had the highest AUC in predicting the occurrence of AKI (ROC-AUC 0.717 and 0.624, p<0.05). However, in the group of patients with class I obesity, only the CG formula modified with a fat-free mass appeared to be predictive of postoperative AKI (ROC-AUC 0.631 p<0.05). None of the equations were accurate in the group of BMI (>35 kg/m2). CONCLUSIONS: eGFR is a poor predictor of AKI, especially in the obese patients undergoing cardiac surgery. The only equation with a moderate predictive power for the class I obese patients was the CG formula modified with the fat-free mass.