Effect of Prewarming on Perioperative Hypothermia in Patients Undergoing Loco-Regional or General Anesthesia: A Randomized Clinical Trial.

Background and Objectives: Redistribution hypothermia occurs during anesthesia despite active intraoperative warming. Prewarming increases the heat absorption by peripheral tissue, reducing the central to peripheral heat gradient. Therefore, the addition of prewarming may offer a greater preservation of intraoperative normothermia as compared to intraoperative warming only. Materials and Methods: A single-center clinical trial of adults scheduled for non-cardiac surgery. Patients were randomized to receive or not a prewarming period (at least 10 min) with convective air devices. Intraoperative temperature management was identical in both groups and performed according to a local protocol. The primary endpoint was the incidence, the magnitude and the duration of hypothermia (according to surgical time) between anesthetic induction and arrival at the recovery room. Secondary outcomes were core temperature on arrival in operating room, surgical site infections, blood losses, transfusions, patient discomfort (i.e., shivering), reintervention and hospital stay. Results: In total, 197 patients were analyzed: 104 in the control group and 93 in the prewarming group. Core temperature during the intra-operative period was similar between groups (p = 0.45). Median prewarming lasted 27 (17-38) min. Regarding hypothermia, we found no differences in incidence (controls: 33.7%, prewarming: 39.8%; p = 0.37), duration (controls: 41.6% (17.8-78.1), prewarming: 45.2% (20.6-71.1); p = 0.83) and magnitude (controls: 0.19 °C · h-1 (0.09-0.54), prewarming: 0.20 °C · h-1 (0.05-0.70); p = 0.91). Preoperative thermal discomfort was more frequent in the prewarming group (15.1% vs. 0%; p < 0.01). The interruption of intraoperative warming was more common in the prewarming group (16.1% vs. 6.7%; p = 0.03), but no differences were seen in other secondary endpoints. Conclusions: A preoperative prewarming period does not reduce the incidence, duration and magnitude of intraoperative hypothermia. These results should be interpreted considering a strict protocol for perioperative temperature management and the low incidence of hypothermia in controls.

Tracheostomy in patients with SARS-CoV-2 reduces time on mechanical ventilation but not intensive care unit stay.

Cross-sectional study to know if tracheostomy influences the time on mechanical ventilation and reduces the ICU stay in patients with SARS-CoV2. From February 14 to May 31, 2020, 29 patients: 23 men and 6 women, with an average age (SD) of 66.4 years (±6,2) required tracheostomy. The average intensive care unit (ICU) stay was 36 days [31-56.5]. The average days on mechanical ventilation was 28,5 days (±9.7). Mean time to tracheostomy was 15.2 days (±9.5) with an average disconnection time after procedure of 11.3 days (±7.4). The average hospital stay was 55 days [39-79]. A directly proportional relation between the number of days of MV and the number of days from ICU admission until tracheostomy showed a significant value of p = 0.008. For each day of delay in tracheostomy, the days of mechanical ventilation were increased by 0.6 days. There was no relation between days to tracheostomy and days to disconnection (p = 0.092). PaO2 / FiO2 (PAFI) before tracheostomy and Simplified Acute Physiology Score III (SAPS III) at admission presented a statistical relation with mortality, with an OR of 1.683 (95%CI; 0.926-2.351; p = 0.078) and an OR of 1.312 (CI95%: 1.011-1.703; p = 0.034) respectively. The length of stay in the ICU until the tracheostomy was not related to the risk of death (p = 0.682). PEEP and PaO2/FiO2 (PAFI) at admission and before tracheostomy and APACHE II, SAPS III and SOFA at admission did not show influence over time on MV. We conclude that the delay in tracheostomy increase the days on mechanical ventilation but does not influence stay or mortality.