Effects of Perioperative Administration of Acetaminophen on Postoperative Shivering

Factors associated with postoperative shivering in patients with maintained core temperature after surgery

BACKGROUND

Postoperative shivering is mainly associated with low body temperature. However, postoperative shivering can develop even at normal or high core temperatures. This study aimed to investigate the factors associated with postoperative shivering in patients with maintained core temperature after surgery.

METHODS

This retrospective study involved 537 patients who had undergone radical surgery for pancreatic cancer under general anesthesia from January 2013 to December 2023. The final analysis included 441 patients whose core temperatures after surgery were ≥ 36.5℃. Logistic regression analysis was performed to estimate the odds ratio (OR) of the incidence of postoperative shivering.

RESULTS

Postoperative shivering occurred in 119 patients. After multivariable-adjusted logistic regression, postoperative shivering was significantly associated with patient age (per 1 year increase; OR = 0.98; 95% confidence interval [CI]: 0.96-0.996; p = 0.02), operation time (per 30 min increase; OR = 1.10; 95% CI: 1.01-1.19; p = 0.03), postoperative core temperature (restricted cubic spline, p = 0.001), postoperative peripheral temperature (restricted cubic spline, p = 0.001), effect site fentanyl concentration at extubation (OR = 0.66; 95% CI: 0.24-0.99; p = 0.049), and acetaminophen use (OR = 0.32; 95% CI: 0.18-0.58; p < 0.001).

CONCLUSIONS

Low peripheral temperature was a risk factor for the occurrence of shivering, even if the core temperature was maintained postoperatively. Peripheral temperature monitoring could be utilized to prevent postoperative shivering. In addition, fentanyl and acetaminophen reduced the occurrence of shivering in patients with maintained core temperature after surgery.

Efficacy of intravenous acetaminophen on postoperative shivering: A meta-analysis of randomized controlled trials

PURPOSE

Postoperative shivering (POS) is a common and vital complication after anesthesia, which may result in serious consequences and uncomfortable experiences. Acetaminophen has been used to treat fever and mild to moderate pain. However, there is not enough evidence to prove its advantage for POS. This meta-analysis aimed to explore the prophylactic use of acetaminophen as a valid agent for POS.

METHODS

Two researchers independently searched PubMed, the Cochrane Library, and Embase for controlled clinical trials. The meta-analysis of randomized controlled trials (RCTs) was performed by Review Manager.

RESULTS

Nine trials with 856 patients were included in our meta-analysis. Acetaminophen significantly reduced POS compared with placebo (pooled risk ratio [RR]: 0.43, 95% confidence interval [CI]: 0.35-0.52). What is more, not only 15 mg/kg but also 1000 mg intravenous acetaminophen could reduce the incidence of shivering compared with placebo.

CONCLUSION

Our present meta-analysis demonstrates that the intravenous prophylactic infusion of acetaminophen may prevent POS, and the results may provide new evidence to expand the clinical value of acetaminophen in addition to its routine usage.

Evaluation of temperature-dependent fluctuations in skin microcirculation flow using a light-emitting diode based photoacoustic imaging device

PURPOSE

Skin microvessels maintain temperature homeostasis by contracting and dilating upon exposure to changes in temperature. Under general anesthesia, surgical invasiveness, including incisions and coagulation, and the effects of anesthetics may cause variations in the threshold temperature, leading to the constriction and dilation of cutaneous blood vessels. Therefore, studies on skin microvascular circulation are necessary to develop appropriate interventions for complications during surgery.

METHODS

We visualized and quantified skin microcirculatory fluctuations associated with temperature variations using a light-emitting diode photoacoustic imaging (LED-PAI) device. The hands of ten healthy volunteers were stressed with four different water temperatures [25℃ (Control), 15℃ (Cold1), 40℃ (Warm), and 15℃ (Cold2)]. The photoacoustic images of the fingers were taken under each condition, and the microvascular flow owing to temperature stress was quantified as the area of photoacoustic signal (S) in each image. The S values were compared with the variations in blood flow (Q) measured by laser Doppler flowmetry (LDF).

RESULTS

The correlation between Q and S according to the 40 measurements was r = 0.45 (p＜0.01). In addition, the values of S under each stress condition were as follows: Scontrol = 10,826 ± 3364 pixels, Scold1 = 8825 ± 2484 pixels, Swarm = 13,369 ± 3001 pixels, and Scold2 = 8838 ± 1892 pixels; the differences were significant. The LDF blood flow (Q) showed similar changes among conditions.

CONCLUSION

These findings suggest that the LED-PAI device could be an option for evaluating microcirculation in association with changes in temperature.

Paracetamol Versus Ondansetron for Prevention of Postoperative Shivering in Liposuction Surgeries Under Combined General Epidural Anaesthesia: A Randomized Controlled Trial

Objective

Postoperative shivering (POS) is considered one of the most common complications that is encountered by the anaesthetists worldwide. Despite using several treatment options, there has not been a clear consensus regarding this issue. This trial was conducted to investigate the efficacy and safety of paracetamol and ondansetron in preventing POS in patients undergoing liposuction procedures under combined general epidural anaesthesia.

Methods

One hundred twenty patients scheduled for liposuction were randomly allocated to one of three groups: group P (paracetamol group) which received 1 g paracetamol intravenously, group O (ondansetron group) which received 8 mg of ondansetron intravenously, and group S (saline group), which received 100 mL normal saline intravenously; all medications were given postoperatively. The primary outcome was the incidence of POS, and the secondary outcomes included shivering score, tympanic temperature, and the occurrence of side effects.

Results

The incidence of occurrence of POS was found to be lower in groups P and O compared to group S with values of 25% and 37.50% vs. 77.50%, respectively, with a P value <0.001. Additionally, the severity of POS was found to be lower in groups P and O compared to group S (P <0.001). Tympanic temperature and complications were comparable between the groups with no significant differences.

Conclusion

Prophylactic use of paracetamol or ondansetron at the end of the procedure was shown to be of great value in reducing the incidence and severity of POS, with no statistically significant difference between the paracetamol and ondansetron groups. Moreover, no significant drawbacks were reported as a result of using these medications.

Thoracic Paravertebral Block Decreased Body Temperature in Thoracoscopic Lobectomy Patients: A Randomized Controlled Trial

Purpose

Thoracic paravertebral block (TPVB) may be highly beneficial for thoracoscopic lobectomy patients, but it may increase the risk of hypothermia. Apart from its anesthetic-reducing effects, this randomized controlled trial aimed to investigate the hypothermic effect of TPVB, and thus optimize its clinical use.

Patients and methods

Adult patients were randomly allocated to two groups: TPVB + general anesthesia (GA) group or GA group. In the TPVB+GA group, the block was performed after GA induction by an experienced but unrelated anesthesiologist. Both the lower esophageal and axillary temperature were recorded at the beginning of surgery (T₀) and every 15 min thereafter (T₁-T₈), and the end of surgery (T_p). The primary outcome was the lower esophageal temperature at T_p. The secondary outcomes included lower esophageal temperature from T₀-T₈ and axillary temperature from T₀-T_p. The total propofol, analgesics, and norepinephrine consumption and the incidence of adverse events were also recorded.

Results

Forty-eight patients were randomly allocated to the TPVB+GA (n=24) and GA (n=24) groups. The core temperature at the end of the surgery was lower in the TPVB+GA group than the GA group (35.90±0.30°C vs 36.35±0.33°C, P<0.001), with a significant difference from 45 min after the surgery began until the end of the surgery (P<0.05). In contrast, the peripheral temperature showed a significant difference at 60 min after the surgery began till the end (P<0.05). TPVB+GA exhibited excellent analgesic and sedative-sparing effects compared to GA alone (P<0.001), though it increased norepinephrine consumption due to hypotension (P<0.001).

Conclusion

Although thorough warming strategies were used, TPVB combined with GA remarkably reduced the body temperature, which is an easily neglected side effect. Further studies on the most effective precautions are needed to optimize the clinical use of TPVB.

Effect of Different Doses of Butorphanol on Postoperative Shivering in Elderly Patients: A Randomized, Double-Blind, Placebo-Controlled Trial

Purpose

This study was designed to investigate the effects of different doses of butorphanol on postoperative shivering and quality of recovery in elderly patients.

Patients and Methods

A total of 147 elderly patients (aged 60 or older) scheduled for elective transurethral resection of the prostate were enrolled in the current study. Patients were randomly and evenly assigned into four groups: Group C (0.9% normal saline), Group B1 (butorphanol 0.01 mg/kg), Group B2 (butorphanol 0.02 mg/kg) and Group B3 (butorphanol 0.03 mg/kg). All drugs were diluted to 5mL and injected intravenously slowly 5 min before induction of anesthesia. The primary outcome measure was the incidence of postoperative shivering in the post-anesthesia care unit. Quality of Recovery-40 (QoR-40) scores were assessed on postoperative day (POD) 1, 2 and 3. Perioperative core and skin temperature, extubation time and adverse events were also recorded.

Results

Patients among the four groups had comparable baseline characteristics. Compared with Group C, the incidence of shivering was significantly lower in Group B2 and B3 (P = 0.006 and P = 0.005, respectively). The QoR-40 scores on POD1 were significantly higher in all butorphanol groups than that in Group C (P < 0.0083). In Group B2 and B3, patients experienced lower pain intensity (P < 0.001). In addition, the incidence of catheter-related bladder discomfort (CRBD) was lower in all butorphanol groups than in Group C (P < 0.0083).

Conclusion

Butorphanol 0.02 or 0.03 mg/kg could effectively prevent the occurrence of postoperative shivering in elderly patients scheduled for transurethral resection of the prostate, provided effective postoperative recovery and postoperative analgesia.

Comparison of the Occurrence of Postoperative Shivering Between Sevoflurane and Desflurane Anesthesia

General anesthetic agents can change the shivering threshold. Sevoflurane and desflurane are widely used as inhalational anesthetics and have also been reported to lower the shivering threshold in a dose-dependent manner. Although the comparison of postoperative shivering (POS) between total intravenous anesthesia and inhalational anesthesia has been reported, there have been no reports on a direct comparison between sevoflurane and desflurane anesthesia and the occurrence of POS in open abdominal surgery. After obtaining approval from the Ethics Review Committee (2020-261), 683 adult patients who underwent open radical surgery for uterine, cervical, or pancreatic cancer under general anesthesia using inhalational anesthetics at Kyushu University hospital between December 2012 and March 2020 were included in this retrospective study. The odds ratio (OR) for the occurrence of POS between the two groups (sevoflurane and desflurane) was calculated. Multivariable-adjusted analysis was performed using possible factors affecting POS. Furthermore, propensity score (PS) matching was conducted using these factors. The multivariable-adjusted OR for the occurrence of shivering in the desflurane group (62 occurrences/356 patients) was 1.06 (95% confidence interval [CI]: 0.69-1.62, p = 0.79) compared with the sevoflurane group (77/327, reference). Similarly, after PS matching, the crude OR for the occurrence of shivering in the desflurane group (47/210) was 1.09 (95% CI: 0.68-1.75, p = 0.72) compared with the sevoflurane group (44/210, reference). Similar results were obtained in the stratified analysis by sex and age. The occurrence of POS is not different between sevoflurane and desflurane anesthesia.

Postspinal anesthesia shivering in lower abdominal and lower limb surgeries: a randomized controlled comparison between paracetamol and dexamethasone

Background

Shivering is known to be a frequent complication in patients undergoing surgery under neuraxial anesthesia with incidence of 40–70%. Although many pharmacological agents have been used to treat or prevent postspinal anesthesia shivering (PSAS), the ideal treatment wasn’t found. This study evaluated the efficacy of paracetamol and dexamethasone to prevent PSAS in patients undergoing lower abdominal and lower limb surgeries.

Methods

Three hundred patients scheduled for surgeries under spinal anesthesia (SA) were allocated into three equal groups to receive a single preoperative dose of oral paracetamol 1 g (P group), dexamethasone 8 mg intravenous infusion (IVI) in 100 ml normal saline (D group) or placebo (C group), 2 h preoperatively, in a randomized, double-blind trial. The primary endpoint was the incidence of clinically significant PSAS. Secondary endpoints included shivering score, the change in hemodynamics, adverse events (e.g., nausea, vomiting and pruritis) and patients` satisfaction.

Results

Clinically significant PSAS was recorded as (15%) in P group, (40%) in D group and (77%) in C group (P < 0.001). The mean blood pressure values obtained over a 5-25 min observation period were significantly higher in the D group (P < 0.001). Core temperature 90 min after SA was significantly lower in the 3 groups compared to prespinal values (P < 0.001). Nausea, vomiting and pruritis were significantly higher in the C group (P < 0.001). P and D groups were superior to C group regarding the patients’ satisfaction score (P < 0.001).

Conclusion

Paracetamol and dexamethasone were effective in prevention of PSAS in patients undergoing lower abdominal and lower limb surgeries compared to placebo controls.

Trial registration

ClinicalTrials.gov Identifier: NCT03679065 / Registered 20 September 2018 - Retrospectively registered, http://www.ClinicalTrial.gov.

Pre Versus Post Implementation of a Pharmacologic Antishivering Protocol During Targeted Temperature Management Following Cardiac Arrest

Background

Targeted temperature management (TTM) is endorsed by various guidelines to improve neurologic outcomes following cardiac arrest. Shivering, a consequence of hypothermia, can counteract the benefits of TTM. Despite its frequent occurrence, consensus guidelines provide minimal guidance on the management of shivering. The purpose of this study was to evaluate the impact of a pharmacologic antishivering protocol in patients undergoing TTM following cardiac arrest on the incidence of shivering.

Methods

A retrospective observational cohort study at a large academic medical center of adult patients who underwent TTM targeting 33 °C following out-of-hospital (OHCA) or in-hospital cardiac arrest (IHCA) was conducted between January 2013 and January 2019. Patients were included in the preprotocol group if they received TTM prior to the initiation of a pharmacologic antishivering protocol in 2015. The primary outcome was incidence of shivering between pre- and postprotocol patients. Secondary outcomes included time from arrest (IHCA) or admission to the hospital (OHCA) to goal body temperature, total time spent at goal body temperature, and percentage of patients alive at discharge. All pharmacologic agents listed as part of the antishivering protocol were recorded.

Results

Fifty-one patients were included in the preprotocol group, and 80 patients were included in the postprotocol group. There were no significant differences in baseline characteristics between the groups, including percentage of patients experiencing OHCA (75% vs. 63%, p = 0.15) and time from arrest to return of spontaneous circulation (17.5 vs. 17.9 min, p = 0.96). Incidence of patients with shivering was significantly reduced in the postprotocol group (57% vs. 39%, p = 0.03). Time from arrest (IHCA) or admission to the hospital (OHCA) to goal body temperature was similar in both groups (5.1 vs. 5.3 h, p = 0.57), in addition to total time spent at goal body temperature (17.7 vs. 18 h, p = 0.93). The percentage of patients alive at discharge was significantly improved in the postprotocol group (35% vs. 55%, p = 0.02). Patients in the postprotocol group received significantly more buspirone (4% vs. 73%, p < 0.01), meperidine (8% vs. 34%, p < 0.01), and acetaminophen (12% vs. 65%, p < 0.01) as part of the pharmacologic antishivering protocol. Use of neuromuscular blockade significantly decreased post protocol (19% vs. 6%, p = 0.02).

Conclusions

In patients undergoing TTM following cardiac arrest, the implementation of a pharmacologic antishivering protocol reduced the incidence of shivering and the use neuromuscular blocking agents. Prospective data are needed to validate the results and further evaluate the safety and efficacy of an antishivering protocol on clinical outcomes.

Incidence of postoperative shivering decreased with the use of acetaminophen: a propensity score matching analysis

OBJECTIVES

The incidence of postoperative shivering is known to be inversely associated with core body temperature. However, previous studies have pointed out that the threshold of shivering could be affected by peripheral temperature or anesthetic agents. These reports pointed specific drugs, though, anesthesia techniques have since advanced considerably. This study aimed to investigate factors associated with postoperative shivering in the context of the current body warming practice.

METHODS

The institutional clinical research ethics committee of Kyushu University approved the study protocol (IRB Clinical Research number 2019-233). This retrospective study involved 340 patients who had undergone radical surgery for gynecological cancer treatment under general anesthesia at our center from December 2012 to June 2019. Logistic regression analysis was performed to estimate the odds ratio (OR) for the incidence of postoperative shivering.

RESULTS

Postoperative shivering developed in 109 out of 340 patients. After multivariate-adjusted logistic regression, the incidences of postoperative shivering decreased significantly with increasing patient age (OR = 0.96; 95%CI: 0.93-0.98; p = 0.0004). Volatile anesthesia technique was less inclined to shiver after surgery than TIVA (OR = 0.55; 95%CI: 0.30-0.99; p = 0.04). Acetaminophen was much less used in the shivering group than in the non-shivering group (OR = 0.49; 95%CI: 0.25-0.94; p = 0.03).

CONCLUSIONS

This study indicated that the development of shivering in patients receiving the anesthetic technique currently used in our hospital was associated with use of acetaminophen or volatile agents, and patient age.