Incidence of postoperative hypothermia and its risk factors in adults undergoing orthopedic surgery under brachial plexus block: A retrospective cohort study

Abstract

Postoperative hypothermia increases patient mortality and morbidity. However, the incidence of, and risk factors for, postoperative hypothermia in patients undergoing surgery under brachial plexus block (BPB) as the primary method of anesthesia remain unclear. This study aimed to determine the incidence of, and risk factors for, postoperative hypothermia in patients undergoing surgery under BPB. We retrospectively analyzed 660 patients aged ≥ 19 years who underwent orthopedic surgery under BPB in our hospital between October 2014 and October 2019. Postoperative hypothermia was defined as a tympanic membrane temperature < 36 °C when the patient arrived in the post-anesthesia care unit. Multivariate logistic regression analysis was performed to identify the independent risk factors for postoperative hypothermia. Postoperative hypothermia was observed in 40.6% (268/660) of patients. Independent risk factors for postoperative hypothermia were lower baseline core temperature before anesthesia (odds ratio [OR] 0.355; 95% confidence interval [CI] 0.185-0.682), alcohol abuse (OR 2.658; 95% CI 1.105-6.398), arthroscopic shoulder surgery (OR 2.007; 95% CI 1.428-2.820), use of fentanyl (OR 1.486; 95% CI 1.059-2.087), combined use of midazolam and dexmedetomidine (OR 1.816; 95% CI 1.268-2.599), a larger volume of intravenous fluid (OR 1.001; 95% CI 1.000-1.002), and longer duration of surgery (OR 1.010; 95% CI 1.004-1.017). Postoperative hypothermia is common in adult patients undergoing orthopedic surgery under BPB. The risk factors identified in this study should be considered to avoid postoperative hypothermia in these patients.

Risk factors for inadvertent intraoperative hypothermia in patients undergoing laparoscopic surgery: A prospective cohort study

“…In this study, a longer duration of surgery increased the risk for hypothermia. This observation was consistent with results from most studies on surgical populations [ 18 , 30 , 31 ]. Heat loss begins from surgical skin preparation [ 32 ], and continues in the first hour after induction of anesthesia, as the core temperature usually decreases by 1–1.5°C [ 33 ].…”

“…Although we observed that factors such as age and longer duration of surgery were associated with intraoperative hypothermia, it should be noted that fewer interventions can be implemented with these factors. Since higher baseline core temperature effectively protected patients against intraoperative hypothermia in our study, and the same effect was obtained in previous studies [ 13 , 31 ], measures can be taken to increase the patient’s baseline core body temperature to an appropriate range before anesthesia. Recently, active warming approaches, such as the use of forced air, have focused mostly on warming the skin surface [ 34 ].…”

Postoperative hypothermia following non-cardiac high-risk surgery: A prospective study of temporal patterns and risk factors

“…The incidence of 60% of patients with temperatures below 36°C and 19% with temperatures below 35°C is compatible with those reported in several other comparable studies [ 4 , 14 , 15 ]. Kongsayreepong et al [ 16 ] found that 57% of the 194 surgical patients in the ICU had a tympanic temperature below 36°C, and 28% had a temperature below 35°C.…”

“…We found that older patients, patients with more comorbidities, and patients who had undergone longer surgeries were more likely to have hypothermia in the ICU. These associations have been reported in the literature [ 4 , 14 , 19 ], indicating that these patients have unfavorable outcomes [ 20 , 21 ].…”

“…Therefore, given these findings, we were able to demonstrate that in this large multicenter study on inadvertent hypothermia in the mixed surgical population of ICU patients, except in cardiac surgery, there is an association between hypothermia and complications, and we also verified possible factors related to this problem. Although other studies [ 1 , 14 ] previously reported risk factors for hypothermia in surgery, they were from retrospective analyzes [ 4 , 14 , 19 ] and failed to find a correlation with postoperative complications [ 15 , 19 ].…”