Intraoperative Core Body Temperature Research Articles

Assessing the Influence of Intraoperative Core Body Temperature on Postoperative Venous Thromboembolism after Abdominal Wall Reconstruction.

Venous thromboembolism (VTE) is a dangerous postoperative complication after abdominal wall reconstruction (AWR). Intraoperative core body temperature has been associated with thrombotic events in other surgical contexts. This study examines the effects of intraoperative temperature on VTE rate after AWR. A retrospective study was performed on AWR patients. Cohorts were defined by postoperative 30-day VTE. Intraoperative core body temperature was recorded as the minimum, maximum, and mean intraoperative temperatures. Study variables were analyzed with logistic regression and cutoff analysis to assess for association with VTE. In total, 344 patients met inclusion criteria. Fourteen patients were diagnosed with 30-day VTE for an incidence of 4.1%. The VTE cohort had a longer median inpatient stay (8 days versus 5 days, P < 0.001) and greater intraoperative change in peak inspiratory pressure (3 mm H2O versus 1 mm H2O, P = 0.01) than the non-VTE cohort. Operative duration [odds ratio (OR) = 1.32, P = 0.01], length of stay (OR = 1.07, P = 0.001), and intraoperative PIP difference (OR = 1.18, P = 0.045) were significantly associated with 30-day VTE on univariable regression. Immunocompromised status (OR = 4.1, P = 0.023; OR = 4.0, P = 0.025) and length of stay (OR = 1.1, P < 0.001; OR = 1.1, P < 0.001) were significant predictors of 30-day VTE on two multivariable regression models. No significant associations were found between temperature metrics and 30-day VTE on cutoff point or regression analysis. Intraoperative core body temperature did not associate with 30-day VTE after AWR, though operative duration, length of stay, immunocompromised status, and intraoperative PIP difference did. Surgeons should remain mindful of VTE risk after AWR, and future research is warranted to elucidate all contributing factors.

The role of warmed-humidified carbon dioxide insufflation in colorectal surgery: A systematic review and meta-analysis.

Maintenance of normothermia is a crucial part of enhanced recovery after colorectal surgery. Dry-cold carbon dioxide (CO2 ) traditionally used for insufflation in laparoscopic surgery and negative pressure operating theatres has been associated with intraoperative hypothermia. Studies suggest that use of warmed-humidified CO2 may promote normothermia. However, due to a scarcity of high-quality studies demonstrating a proven benefit on intraoperative core body temperature, its use in colorectal surgery remains limited. Therefore, the aim of this review was to evaluate the effects of warmed-humidified CO2 compared to traditional dry-cold CO2 , or ambient air in operating theatres, during colorectal surgery. A search of Medline, EMBASE, and CENTRAL was performed. Randomised controlled trials (RCTs) that compared patients receiving warmed-humidified CO2 with either dry-cold CO2 insufflation in laparoscopic procedures or no insufflation during open surgery were included. The primary outcome was change in intraoperative core body temperature. Secondary outcomes included length of stay, operating time, return of gastrointestinal function, wound infection, and postoperative pain. A pairwise meta-analysis was performed using inverse variance random effects. Among the six RCTs included, 208 patients received warmed-humidified CO2 (42.3% female, mean age: 65.8 years) and 210 patients received either dry-cold CO2 in laparoscopic procedures or no gas insufflation during open procedures (46.2% female, mean age: 66.1 years). No significant difference was found for change in intraoperative core body temperature (MD = 0.01, 95% CI: -0.1, 0.11, p = 0.90, very low certainty). Patients in the warmed-humidified CO2 group had significantly higher pain scores on postoperative day 1 (MD = 1.61, 95% CI: 0.91, 2.31, p < 0.05, very low certainty). No significant differences were found in any of the other secondary outcomes studied. Patients undergoing colorectal surgery receiving warmed-humidified CO2 do not experience any clinically meaningful difference in core body temperature change compared to their counterparts receiving dry-cold CO2 insufflation or no insufflation. However, patients may report greater pain scores on postoperative day 1 with warmed-humidified CO2 . There is likely no clinically important difference between warmed-humidified CO2 and dry-cold CO2 for patients undergoing colorectal surgery. Patient, clinician, and institution factors should be considered when deciding between these two insufflation modalities.

Intraoperative Hypothermia Is Not Associated with Surgical Site Infections after Total Hip or Knee Arthroplasty.

Maintaining perioperative normothermia decreases the post-surgery surgical site infection (SSI) rate. We investigated whether SSI is associated with intraoperative hypothermia in total hip (THA) and total knee (TKA) arthroplasties by retrospectively analyzing 297 THA and TKA cases. The patients' intraoperative core body temperature (BT) was measured by bladder catheter or forehead sensor. We evaluated the associations between SSI and intraoperative BT and other variables and patient characteristics. Fifty-six patients (18.8%) had hypothermia (BT <36°C); 43 developed SSI (14.5%); only five had hypothermia (11.6%). Intraoperative hypothermia and SSI were not significantly associated. The SSI group had more men (34.9% vs. 18.1%) and THA patients (77.4%), a longer mean surgical duration (174.3 vs. 143.5 mins), and a higher average BT (36.4°C vs. 36.2°C) than the no-SSI group. The SSI patients had a higher intraoperative BT. A multivariable analysis revealed that SSI was associated with male sex (OR 2.3, 95%CI: 1.031-4.921, p=0.042), longer surgery (OR, 1.01, 95%CI: 1.003-1.017, p=0.004), THA (OR 3.6, 95%CI: 1.258-10.085, p=0.017), and intraoperative BT >36.0°C (OR 3.6, 95%CI: 1.367-9.475, p=0.009). Intraoperative hypothermia was not associated with SSI in adults who underwent THA or TKA. These results suggest that hypothermia might not be the problem for SSI.

Effectiveness of preoperative prewarming for maintenance of intraoperative core body temperature: an Meta-analysis

Objective To systematically evaluate the effectiveness of preoperative prewarming for maintenance of intraopera-tive core body temperature, so as to provide clinical evidence for perioperative temperature management. Methods We retrieved PubMed, Web of Science, the Cochrane Library, EMBACE, CINAHL, CNKI, Wanfang Database, CQVIP and China Biology Medicine disc, so as to comprehensively search randomized controlled trials (RCTs) about preoperative prewarming for maintenance of intraopera-tive core body temperature. The retrieval time was limited from January 2000 to April 2019 and the references of the included trials were also reviewed. Two researchers independently screened literature according to the inclusion and exclusion criteria, evaluated the quality of the included literature, and extracted data. RevMan 5.3 software was adopted to perform Meta-analysis. Results Fourteen RCTs involving a total of 902 patients were included. The results of Meta-analysis indicated that the preoperative prewarming group presented a remarkably increased core body temperature 30 min, 60 min, and 90 min after anesthesia induction and at the end of opera-tion, as well as a markedly decreased incidence of intraoperative hypothermia and postoperative hypothermia, compared with the con-trol group (P 0.05). Conclusions Preoperative prewarming can effectively increaese intraoperative core body temperature and reduce the inci-dence of hypothermia. Key words: Prewarming; Intraoperative; Core body temperature; Hypothermia; Meta-analysis

Prevention of Perioperative Hypothermia: A Prospective, Randomized, Controlled Trial of Bair Hugger Versus Inditherm in Patients Undergoing Elective Arthroscopic Shoulder Surgery

To determine if a clinically significant difference in the core body temperature (CBT) exists between the Bair Hugger (BH) and Inditherm (IT) warming devices in patients undergoing arthroscopic shoulder surgery. This was a parallel, 2-treatment, prospective, randomized, controlled trial conducted in patients undergoing elective arthroscopic shoulder surgery in the beach-chair position using room-temperature irrigation fluid. The BH was used as the indicative forced-air warming device, whereas the IT served as the indicative resistive heating system. By use of a minimal clinically significant difference of 0.6°C and standard deviation of 0.6°C, a power analysis showed that a sample size of 90 patients (45 per group) would be required. Patients fulfilling the inclusion criteria were recruited from the clinics of the senior authors. Anesthetic and surgical protocols were standardized. The intraoperative CBT was recorded every 5 minutes using a nasopharyngeal thermistor probe. Demographic data as well as the volume of irrigation fluid used were also noted. A steady decline in the CBT was observed in both groups up to 30 minutes after induction of anesthesia. Beyond 30 minutes, the BH group showed a gradual increase in temperature whereas it continued to decline in the IT group. A statistically significant difference in the CBT was observed from 60 minutes onward (P= .025). This difference continued to increase up to 90 minutes (P < .001). At no time was a rise in the CBT observed in the IT group. At completion of the study and surgical procedure, 13 of 47 patients in the BH group and 32 of 44 patients in the IT group had hypothermia (P= .0002). The CBT was statistically significantly better with the use of the BH compared with the IT mattress. However, the differences in the CBT did not reach the level of clinical significance of 0.6°C. Far fewer patients in the BH group had hypothermia at the end of surgery. Therefore, this study supports the use of the BH in elective arthroscopic shoulder surgery for the prevention of hypothermia. Level I.

Effect of forced-air warming blanket position in elective lumbar spine surgery: Intraoperative body temperature and postoperative complications

Background:Perioperative hypothermia is linked to multiple postoperative complications including increased surgical bleeding, surgical site infection, myocardial events, and increased length of hospital stay. The purpose of this study is to determine the effects of forced-air warming blanket position, above the shoulders versus under the trunk/legs, on intraoperative core body temperature and perioperative complications in elective lumbar spine surgery.Methods:After IRB approval, patients were enrolled in a consecutive fashion and randomized to either upper body (Group I) or lower body (Group II) groups. Primary outcomes were intraoperative body temperature, incidence of hypothermia, postoperative complications, and infection. Secondary outcomes included blood loss, operative time, and length of stay.Results:Seventy-four patients were included (Group I, 38; Group II, 36, mean age 60.7 years, 54% of male). Average patient follow-up was 69 ± 33.6 days in Group I and 67 ± 34.6 days in Group II. Average intraoperative body temperature was 35.7 in Group I and 35.8 in Group II (P = 0.27). Incidence of critical hypothermia (T < 35°C) was 18.4% and 11.1% in Groups I and II, respectively (P = 0.52). Incidence of mild hypothermia (T: 35°C–36°C) was 34.2% and 30.56% in Groups I and II, respectively (P = 0.81). Separately, pooled analysis comparing average body temperature and incidence infection demonstrated a relationship between mild hypothermia and infection (P = 0.03).Conclusion:Compared to using a lower body Bair Hugger under the patient, using standard upper body Bair Hugger may be associated with increased surgical site infection. Given equivalent body warming, we recommend using the lower body Bair Hugger to avoid infection.

Preoperative factors affecting the intraoperative core body temperature in elective hysterectomy under general anesthesia

Background: Hypothermia is common in patients undergoing anesthesia surgery and it may increase the potential risk of post-operative complications. The purpose of this study was to investigate the intraoperative factors that affect the core temperature of women after hysterectomy. Materials and Methods: One hundred and four female patients aged 18 and older, who were treated with elective open hysterectomy, were studied. The authors evaluated the incidence of hypothermia with respect to demographics, clinical, and anesthesia characteristics in two patients groups (hypothermic vs. normothermic). Results: The incidence of intraoperative hypothermia was 53.8. Advanced age (OR=6.449; 95% CI 3.603-14.397, p &lt; 0.001), higher BMI (OR=5.879; 95% CI 5.122-7.325), higher intraoperative core body temperature (OR=0.483; 95% CI 0.432-0.578), large surgeries (OR=4.149; 95% CI 3.549-5.881, p &lt; 0.001), and the number of opioids (OR=0.199; 95% CI 0.084-0.428) were found to be the most important predictors for hypothermia intraoperatively. There was significant statistical difference between the two groups with respect to American Society of Anaesthesiologists’ (ASA) score, induction to anesthesia with propofol and sevoflurane, and the administration of muscle relaxants perioperatively. Conclusions: The application of an appropriate, simple, and low-cost heating method, either by administrating warmed intravenous fluids or using an air-heating flow device, can help to prevent surgical patients’ hypothermia and its possible dangerous complications.

Factors Influencing Intra-Operative Body Temperature in Laparoscopic Colectomy Surgery under General Anesthesia: An Observational Cohort

Purpose: This study aimed to identify factors influencing intra-operative core body temperature (CBT), and to develop a predictive model for intra-operative CBT in laparoscopic abdominal surgery. Methods: The prospective observational study involved 161 subjects, whose age, weight, and height were collected. The basal pre-operative CBT, pre-operative blood pressure, and heartbeat were measured. CBT was measured 1 hour and 2 hours after pneumoperitoneum. Results: Explanatory factors of intra-operative hypothermia (<36˚C) were weight (β=.361, p<.001) and pre-operative CBT (β=.280, p=.001) 1 hour after pneumoperitoneum (Adjusted R2=.198, F=7.56, p<.001). Weight was (β=.423, p<.001) and pre-operative CBT was (β=.206, p=.011) 2 hours after pneumoperitoneum (Adjusted R2=.177, F=5.93, p<.001). The researchers developed a predictive model for intra-operative CBT (˚C) by observing intra-operative CBT, body weight, and pre-operative CBT. The predictive model revealed that intra-operative CBT was positively correlated with body weight and pre-operative CBT. Conclusion: Influence of weight on intra-operative hypothermia increased over time from 1 hour to 2 hours after pneumoperitoneum, whereas influence of pre-operative CBT on intraoperative hypothermia decreased over time from 1 hour to 2 hours after pneumoperitoneum. The research recommends pre-warming for laparoscopic surgical patients to guard against intra-operative hypothermia.

Effect of electrically heated humidifier on intraoperative core body temperature decrease in elderly patients: a prospective observational study

Background: Core body temperature (TC) can decrease during general anesthesia. Particularly in elderly patients, more aggressive strategies to prevent intraoperative hypothermia may be required. Here, we investigated the effect of a heated humidifier on intraoperative TC decrease in the elderly. Methods: Twenty-four elderly patients were randomly assigned into two groups: those who used a heated humidifier (group H) and those who used a conventional ventilator circuit with a heat moisture exchanger (group C). TC was measured continuously at the esophagus at several time-points during surgery. Results: In group C, TC significantly decreased 90 minutes after skin incision (P < 0.001), while significant differences were not noted in group H during surgery. Comparing the two groups, TC decreased more in group C than in group H at 60, 90, 120, and 150 minutes after skin incision (group C vs. group H: −0.6°C vs. −0.3°C, P = 0.025; −0.7°C vs. −0.4°C, P = 0.012; −0.9°C vs. −0.4°C, P = 0.006; and −1.0°C vs. −0.5°C, P = 0.013, respectively). There were no significant differences between the two groups for any other parameters. Conclusions: A heated humidifier is more effective in preventing intraoperative TC decrease in elderly patients than a heat moisture exchanger. However, further studies with a larger population are required to substantiate its clinical use. Keywords: Body temperature; Closed circuit anesthesia; Heating; Humidity; Hypothermia

전신마취하 개복술 환자의 수술중 체온에 영향을 미치는 요인

Purpose: The study was conducted to identify factors affecting the intraoperative core body temperature (CBT) of surgical patients under general anesthesia. Methods: This study was performed through a prospective descriptive research design. The sample consisted of 138 patients who had undergone elective laparotomy surgery. Age, weight, height, the basal preoperative CBT, blood pressure, and heart rate were collected. CBT was again measured at induction of anesthesia, 1 hour, 2 hours, and 3 hours following induction of general anesthesia. Results: Factors affecting intraoperative hypothermia < 36˚C at 1 hour following induction, were CBT at induction and total body fat (TBF) (R 2 = .569, p < .001); at 2 hours after induction, CBT at induction and TBF (R 2 = .507, p < .001); at 3 hours after induction, CBT at induction (β = 0.34), TBF, age and the ambient temperature in the operating room (R 2 = .449, p < .001). Conclusion: CBT at induction and TBF appear to be factors affecting intraoperative CBT within 2 hours after induction of anesthesia; CBT at induction, TBF, advanced age and the ambient temperature after 3 hours following induction. We recommend keeping surgical patients warm before induction of anesthesia and providing intraoperative warming for surgical patients of advanced age with low TBF and when the duration of general anesthesia will last more than 3 hours.

Excessive bleeding predictors after cardiac surgery in adults: integrative review.

To integrate literature data on the predictors of excessive bleeding after cardiac surgery in adults. Perioperative nursing care requires awareness of the risk factors for excessive bleeding after cardiac surgery to assure vigilance prioritising and early correction of those that are modifiable. Integrative literature review. Articles were searched in seven databases. Seventeen studies investigating predictive factors for excessive bleeding after open-heart surgery from 2004-2014 were included. Predictors of excessive bleeding after cardiac surgery were: Patient-related: male gender, higher preoperative haemoglobin levels, lower body mass index, diabetes mellitus, impaired left ventricular function, lower amount of prebypass thrombin generation, lower preoperative platelet counts, decreased preoperative platelet aggregation, preoperative platelet inhibition level >20%, preoperative thrombocytopenia and lower preoperative fibrinogen concentration. Procedure-related: the operating surgeon, coronary artery bypass surgery with three or more bypasses, use of the internal mammary artery, duration of surgery, increased cross-clamp time, increased cardiopulmonary bypass time, lower intraoperative core body temperature and bypass-induced haemostatic disorders. Postoperative: fibrinogen levels and metabolic acidosis. Patient-related, procedure-related and postoperative predictors of excessive bleeding after cardiac surgery were identified. The predictors summarised in this review can be used for risk stratification of excessive bleeding after cardiac surgery. Assessment, documentation and case reporting can be guided by awareness of these factors, so that postoperative vigilance can be prioritised. Timely identification and correction of the modifiable factors can be facilitated.

Relationship Between Hypothermia and Blood Loss in Adult Patients Undergoing Open Lumbar Spine Surgery

Intraoperative blood loss during open lumbar spine surgery is associated with adverse events and is a contributor to higher medical costs. Intraoperative hypothermia has been shown to increase blood loss and postoperative allogeneic blood transfusion rates in other realms of orthopedic surgery, but it has not been studied extensively in patients undergoing spine surgery. To determine whether a clinically relevant association exists between intraoperative core body temperature and blood loss or transfusion rates in adult patients undergoing open lumbar spine surgery. In this retrospective medical record review, the surgical records of 174 adult patients who underwent open, nonmicroscopically assisted lumbar spine surgery performed by a single surgeon at a single institution were evaluated. Maximum, minimum, and average temperature, hypothermic temperature, and temperature range parameters were compared with intraoperative, total, and net blood loss and blood transfusion parameters. Additional patient demographic and perioperative characteristics were compared with blood loss and transfusion parameters to determine potential confounders. Analysis of variance, Spearman rank correlation, and generalized multiple linear regression analysis were performed to test for an association between temperature and blood loss or allogeneic transfusion rates. Statistical significance was set at P≤.05. After implementation of exclusion criteria, 160 patient records and 168 surgical procedures were included in the analysis. For patients whose temperature decreased to a hypothermic level at some point during the procedure, hypothermic maximum temperature was protective against blood loss on bivariate analysis (P≤.02), but this finding lost significance after multivariate regression analysis (P>.09). Temperature range was associated with increased blood loss on bivariate analyses (P<.001) but also lost significance after adjusting for covariates in regression analysis (P≥.65). Surgery type (P≤.001) and operative time (P≤.001) were the most robust predictors of increased blood loss (P=.005) and were significantly associated with temperature (P<.001). No effect was found on perioperative blood loss from any temperature parameter or hypothermia in adult patients who underwent lumbar spine surgery once covariates were controlled for with multivariate analysis. One possible interpretation of these results is that the effect of temperature on blood loss can be explained by its strong relationship to the confounders of operative time and surgery type.

Preoperative factors affecting the intraoperative core body temperature in abdominal surgery under general anesthesia: an observational cohort.

The study was conducted to identify preoperative factors affecting the intraoperative core body temperature in abdominal surgery under general anesthesia. This study was performed through prospective descriptive research design. The setting was a 1300-bed university hospital in Incheon, South Korea. The sample consisted of 147 patients who had undergone elective abdominal surgery under general anesthesia. Age, weight, and height were collected on a preoperative visit to general unit, and body mass index, body surface area, and total body fat were calculated. The basal preoperative core body temperature (CBT), preoperative blood pressure, and heart rate were measured. Core body temperature was again measured at 1, 2, and 3 hours following general anesthesia. Predictive factors of intraoperative hypothermia of less than 36°C were preoperative CBT (β = .44), weight (β = .41), preoperative heart rate (β = .20), and age (β = -.13) at 1 hour after anesthesia (R = 0.658, F = 68.3, P < .001); preoperative CBT (β = .33), weight (β = .37), preoperative heart rate (β = .22), and age (β = -.24) at 2 hours after anesthesia (R = 0.631, F = 60.8, P < .001); and age (β = -.34), weight (β = .36), preoperative CBT (β = .30), and preoperative heart rate (β = .20) at 3 hours after anesthesia (R = 0.665, F = 70.6, P < .001). Low preoperative body temperature and low weight seem to be risk factors of intraoperative hypothermia during 2 hours after anesthesia and advanced age and low weight at 3 hours following anesthesia. We recommend prewarming and intraoperative warming through forced air warming devices and covering a patient with a warm blanket during transportation. This procedure is necessary for the abdominal surgical patients of advanced age with low weight and duration of general anesthesia to last more than 1 hour.

Insertion of a temperature probe into the ProSeal® laryngeal mask airway drainage tube

Background: Temperature monitoring is one of the minimum mandatory monitoring standards of anaesthesiology. Intraoperative hypothermia and hyperthermia can both be detrimental for patients. We introduced a temperature probe into a Proseal® laryngeal mask airway (LMA) drainage tube, and measured patient temperatures and evaluated temperature dynamics.Methods: After obtaining informed consent, a thermistor probe (Datex S5®) was inserted into the drainage tube of a Proseal® LMA. This was done to monitor the intraoperative core body temperature in the distal one-third of the oesophagus, and was undertaken prospectively in 123 patients in whom the placement of an orogastric tube was not mandatory (e.g. orthopaedic, gynaecological and ophthalmic surgery). To confirm the position of the thermistor probe, a fibre-optic bronchoscope was inserted in the drainage tube immediately after removal of the temperature probe.Results: An increase in temperature, of 2°C ± 1.2°C, was observed from the midpoint to the tip of the drainage tube in more than 95% of cases. As the thermistor crossed the distal end of the drainage tube and entered the lower third of the oesophagus, there was a rapid increase in temperature.Conclusion: This is a useful method for monitoring core temperature in cases where a gastric tube is not required intraoperatively. This method can be used in all supraglottic devices that have a drainage tube, and is effective, cheap and reliable, with easy accessibility for accurate core temperature measurement.

Mild Intraoperative Hypothermia Reduces Free Tissue Transfer Thrombosis

Patients undergoing free tissue transfer are particularly susceptible to hypothermia. The goal was to investigate the impact of intraoperative core body temperature on free flap thrombosis. Two hundred twelve cases of free flap reconstruction at Yale-New Haven Hospital between 1992 and 2008 were reviewed. Free flap thrombosis was defined by complete flap necrosis or direct visualization of arterial or venous thrombosis. Temperature measurements were calibrated to bladder temperatures as measured by Foley catheter sensor. Through logistic regression analysis, maximum and minimum intraoperative temperatures were determined to be statistically significant predictors of free flap thrombosis. The optimal temperature was calculated to be 36.2 °C, and maximum intraoperative temperatures between 36.0 °C and 36.4 °C showed lower thrombosis rates than super-warmed patients ( P < 0.03). Therefore, free flap patients should be mildly hypothermic at 36.0 °C to 36.4 °C, compared with normothermia at 37.5 °C, as measured in the bladder. A prospective randomized trial investigating thrombosis rates and intraoperative temperature should be undertaken.

Hypothermia associated withpercutaneous nephrolithotomy

Objectives. To characterize the perioperative fall in core body temperatureassociated with percutaneous nephrolithotomy, and to identify patients at greater risk of hypothermia. Methods. A retrospective review was undertaken of core body temperatures in 77 patientswho underwent 95 percutaneous-nephrolithotomy (PNL) procedures using room temperature irrigants over a 3 year period. Intraoperative temperature measurements were obtained via an esophageal thermistor probe. Results. Mean core body temperature fell from 36.7°C preoperatively to 35.8°C afterretrograde manipulations and subsequent patient positioning before commencing the renal puncture. The mean core temperature fell an additional mean 1.0°C during the percutaneous nephrolithotomy. This additional temperature drop was proportional to the length of the procedure. Female patients had a significantly greater decline in intraoperative core body temperature than male patients (p < 0.01). Obese patients preserved their preoperative temperature more efficiently. Blood loss and advanced age had no impact on the occurrence of hypothermia. Mean preoperative temperature was regained on average within 3 hours postoperatively. Conclusions. Hypothermia occurs in the majority of patients undergoing PNL. Nearly an equivalent fall in temperature is seen during presurgical preparation, induction of anesthesia, and patient positioning as is seen during the surgical procedure itself. Efforts to preserve core body temperature both before and during the percutaneous procedure may reduce the degree of hypothermia and its potential complications.