Postoperative hypothermia in geriatric patients undergoing arthroscopic shoulder surgery

Comparison of the incidence of inadvertent perioperative hypothermia between general anesthesia and interscalene brachial plexus block in shoulder arthroscopy: A randomized prospective study

INTRODUCTION

Inadvertent perioperative hypothermia (IPH), defined as core body temperature below 36°C, is associated with various complications. Shoulder arthroscopy is a risk factor of IPH. This study aimed to compare the incidence of IPH between general anesthesia (GA) and interscalene brachial plexus block (ISBPB) for shoulder arthroscopy.

METHOD

Patients scheduled for shoulder arthroscopy were prospectively enrolled and randomly assigned to GA or ISBPB groups. The body temperature of the patients was measured from baseline to the end of anesthesia and in the post-anesthetic care unit to compare the incidence of IPH.

RESULTS

Of the 114 patients initially identified, 80 were included in the study (GA = 40, ISBPB = 40). The incidence of IPH differed significantly between the groups, with GA at 52.5% and ISBPB at 30.0% (P = .04). Profound IPH (defined as < 35.0°C) occurred in 2 patients with GA. Upon arrival at the post-anesthesia care unit, the GA group exhibited a significantly lower mean body temperature (35.9 ± 0.6°C) than the ISBPB group (36.1 ± 0.2°C, P = .04).

CONCLUSION

The incidence of IPH in the GA group was higher than that in the ISBPB group during shoulder arthroscopy, suggesting that ISBPB may be a preferable anesthetic technique for reducing risk of IPH in such procedures.

Prewarming for Prevention of Hypothermia in Older Patients Undergoing Hand Surgery Under Brachial Plexus Block

Background

Older patients are more vulnerable to inadvertent perioperative hypothermia. Prewarming contributes to the prevention of inadvertent perioperative hypothermia in patients under general or neuraxial anesthesia. However, the effects of brachial plexus block (BPB) on thermoregulation and the efficacy of prewarming in the prevention of hypothermia in older patients undergoing surgery with BPB remain unclear. This study evaluated the effects of BPB on thermoregulation and the efficacy of prewarming during BPB in older patients.

Methods

Patients aged ≥65 years were randomly allocated to receive either standard preoperative insulation (control group, n=20) or preanesthetic forced-air warming for 20 minutes before BPB (prewarming group, n=20). During the perioperative period, tympanic temperatures were measured. Thermal comfort scores and shivering grades were also obtained.

Results

The tympanic temperatures at the end of surgery did not differ between the groups (36.9°C±0.5°C and 37.0°C±0.4°C in the control and prewarming groups, respectively; p=0.252). The maximum temperature change was significantly lower in the prewarming group compared to the control group (0.36°C±0.4°C and 0.65°C±0.3°C, respectively; p=0.013). The hypothermia incidence and severity, thermal comfort scores, and shivering grades did not differ between the groups.

Conclusion

Regardless of the application of prewarming, BPB did not cause a clinically significant impairment of thermoregulation. Moreover, the efficacy of prewarming appeared to be low; thus, it may not be routinely required in patients undergoing orthopedic hand surgery under BPB.

Mean Temperature Loss During General Anesthesia for Laparoscopic Cholecystectomy: Comparison of Males and Females

Introduction

Mild hypothermia is common after general anesthesia. It is associated with discomfort and shivering. Greater fall of temperature is associated with more devastating complications. Data regarding the effect of gender on perioperative hypothermia is scanty.

Objectives of the study

To determine and compare mean core temperature loss in males and females undergoing laparoscopic cholecystectomy under general anesthesia.

Setting and design

Descriptive cross-sectional study in a tertiary care teaching hospital.

Subjects and methods

Ninety-seven elective laparoscopy patients were included through non-probability consecutive sampling. Intraoperatively, there was standardization of monitoring equipment, drapes, operation room temperature (21-22 °C), humidity (50%), irrigation fluid temperature (37 °C), peritoneal CO₂ temperature (21-22 °C), anesthetic fresh gas flow rates at induction and maintenance. Temperature recording equipment (nasopharyngeal probe) and temperature recording interval (10 minutes) were also standardized from induction till the end of surgery. Final temperature was recorded at the end of surgery before emergence.

Results

Mean temperature loss was 0.73 ⁰C ± 0.47⁰C. Mean loss was significant in males compared to females with a mean difference of 0.28°C ± 0.93⁰C; P-value= 0.003.

Conclusion

Mean temperature decreases significantly in laparoscopic cholecystectomy patients under general anesthesia. We recommend that more care is needed to prevent hypothermia in male patients because of their higher susceptibility to hypothermia.

The effect of interscalene brachial plexus block with propofol sedation on preventing perioperative hypothermia during arthroscopic shoulder surgery

Background

Interscalene brachial plexus block (ISBPB) is commonly used with general anesthesia for postoperative pain management in shoulder surgery. This study investigated the incidence of hypothermia and changes in the body temperature in patients undergoing arthroscopic shoulder surgery under ISBPB with propofol sedation.

Methods

This retrospective study enrolled 220 patients who underwent arthroscopic shoulder surgery. Patients were divided into general anesthesia (n = 34) and ISBPB with propofol sedation (n = 186) groups, and medical records were retrospectively compared. In addition, patients from the ISBPB group were further divided according to age (elderly [≥ 65 years], n = 98 vs. young [< 65 years], n = 88), and the incidence of hypothermia and changes in the body temperature were compared.

Results

Twenty-seven patients (12.3%) experienced perioperative hypothermia (range: 35.3–35.9℃). The incidence of perioperative hypothermia was 29.4% and 9.1% in the general anesthesia and ISBPB groups, respectively, and there was a significant difference between the two groups (P = 0.002). The incidence of perioperative hypothermia according to age in the ISBPB group was 9.2% and 9.1% in the elderly and young groups, respectively, and there was no significant difference between the two groups (P = 0.983).

Conclusions

The incidence of perioperative hypothermia during arthroscopic shoulder surgery under ISBPB with propofol sedation is lower than that under general anesthesia. Furthermore, when using ISBPB with propofol sedation, the incidence of perioperative hypothermia in elderly patients is similar to that in younger patients.

Anesthetic management of geriatric patients

The number of elderly patients who frequently access health care services is increasing worldwide. While anesthesiologists are developing the expertise to care for these elderly patients, areas of concern remain. We conducted a comprehensive search of major international databases (PubMed, Embase, and Cochrane) and a Korean database (KoreaMed) to review preoperative considerations, intraoperative management, and postoperative problems when anesthetizing elderly patients. Preoperative preparation of elderly patients included functional assessment to identify preexisting cognitive impairment or cardiopulmonary reserve, depression, frailty, nutrition, polypharmacy, and anticoagulation issues. Intraoperative management included anesthetic mode and pharmacology, monitoring, intravenous fluid or transfusion management, lung-protective ventilation, and prevention of hypothermia. Postoperative checklists included perioperative analgesia, postoperative delirium and cognitive dysfunction, and other complications. A higher level of perioperative care was required for older surgical patients, as multiple chronic diseases often makes them prone to developing postoperative complications, including functional decline and loss of independence. Although the guiding evidence remains poor so far, elderly patients have to be provided optimal perioperative care through close interdisciplinary, interprofessional, and cross-sectional collaboration to minimize unwanted postoperative outcomes. Furthermore, along with adequate anesthetic care, well-planned postoperative care should begin immediately after surgery and extend until discharge.