Bedside Shivering Assessment Scale Research Articles

Effect of Ondansetron on Postoperative Pain and Vomiting after Acute Appendicitis Surgery: A Placebo-Controlled Double-Blinded Randomized Clinical Trial.

Common postoperative complications following surgery, particularly acute appendicitis surgery, include postoperative pain and vomiting, which can cause discomfort and delay recovery time. A randomized double-blinded placebo-controlled clinical trial was conducted with 80 cases of acute appendicitis of American Society of Anesthesiologists (ASA) physical status I or II and aged 18-60 y/o scheduled for appendectomy under general anesthesia. Patients were randomly divided into two equal groups: group A received 4 mg of ondansetron IV (2 ml) and group B received 2 ml of normal slain IV (placebo). Pain according to VAS, nausea and vomiting according to clinical symptoms, shivering and sedation according to the Bedside Shivering Assessment Scale (BSAS), and the Ramsay Sedation Scale (RSS) at 2, 6, 12, and 24 hours after surgery were evaluated and compared between the groups. There was a significant decline in the severity of pain only at 2 hours after surgery between the ondansetron and control groups (5.3 ± 1.0 vs. 6.0 ± 1.0; p=0.01), not showing a difference between the groups at 6, 12, and 24 hours after appendectomy. Postoperative nausea and vomiting at 2 (5% vs. 25%; p=0.03) and 6 (7.5% vs. 27.5%; p=0.04) hours after appendectomy in the ondansetron group. At different times, the ondansetron and control groups did not differ in terms of pethidine consumption or sedation. In conclusion, our study found that ondansetron was effective in reducing postoperative vomiting after acute appendicitis surgery. However, it did not show a clinically significant effect on postoperative pain. This trial is registered with IRCT20230722058883N1.

Effect of Intrathecal Fentanyl on Shivering During Spinal Anesthesia

IntroductionPerioperative shivering is a common complication following spinal anesthesia. Apart from the obvious discomfort, shivering is associated with a number of potentially deleterious sequels. The objective of this research is to study the effect of intrathecal fentanyl on shivering. MethodsRetrospectively two hundred patients were included and divided into two equal groups. In group A, 3.5 ml of 0.5% heavy bupivacaine was mixed with 25 mcg (0.5 ml) of fentanyl to make 4 ml solution out of which the enrolled patients received 3.5 ml of the mixed solution. Group B received 3.5 ml of 0.5% plain heavy bupivacaine. Modified bedside shivering assessment scale was used to score the intensity of shivering.ResultsIn group A, 16 patients (16%) had severe shivering, 30 patients (30%) had moderate shivering and 46 (46%) had mild shivering. Rest of the patients (8%) did not experience shivering. In group B, all the patients had shivering. Severe shivering was observed in 28 patients (28%), moderate shivering was observed in 62 patients (62%) and mild shivering in 10 patients (10%).ConclusionsFentanyl as an adjuvant to heavy bupivacaine during spinal anesthesia decreases the incidence and severity of shivering compared to bupivacaine alone.

554: EVALUATION OF THE USE OF DANTROLENE FOR REFRACTORY SHIVERS WITHIN THE NEUROCRITICAL CARE UNIT

Introduction: Targeted temperature management (TTM) is frequently used for the prevention of secondary injury in subarachnoid hemorrhage, intracranial hemorrhage and ischemic stroke. Shivering is common in patients undergoing TTM and causes detrimental effects on systemic oxygen consumption, brain tissue oxygenation and intracranial pressure. After standard of care for the management of shivering, limited data on the use of dantrolene has been reported with potential efficacy, although the prevalence of adverse events is unknown. The goal of this study is to evaluate the safety and efficacy of dantrolene for refractory shivering in patients undergoing TTM. Methods: A retrospective review was completed of patients admitted to the neurocritical care unit that received continuous dantrolene for this indication. Data extracted included TTM modality, neurologic injury type with associated severity score, and bedside shivering assessment scale (BSAS) score 6 hrs before, during and 6 hrs after dantrolene. Also collected included dantrolene dose, duration, route and potential adverse effects related to dantrolene. Results: 30 patients met inclusion with 24 admitted for a neurologic injury of aneurysmal subarachnoid hemorrhage with median Hunt Hess score of 4 (IQR 3-4.25) and modified Fisher scale score of 3 (IQR 3-4). Appropriate initial dosing weight was utilized in 60% of patients and 93.3% underwent TTM using an Arctic SunTM. The median duration of dantrolene therapy was 3 days (IQR 1.25-4.75). BSAS decreased from 6 hrs prior to dantrolene with a median score of 2 (IQR 1-3) to 1 (IQR 0-2) and 0.5 (IQR 0-1) at 6 and 36 hrs post dantrolene. 43.3% of patients experienced an adverse event related to the dantrolene infusion. Infiltration and transaminitis were the most common, both accounting for 38.5% of events. Conclusions: Dantrolene use for refractory shivering exhibited a trend in decreasing BSAS signaling potential efficacy, though additional evaluation is needed to fully assess. A large portion of patients encountered an adverse event attributable to dantrolene. Based on this evidence, it is recommended that dantrolene be administered via only central venous catheter for refractory shivering and daily liver function panels should be monitored during administration to prevent infiltration and transaminitis.

Targeted Temperature Management Protocol in a Pediatric Intensive Care Unit: A Quality Improvement Project.

In patients with acute neurological injury, abrupt temperature change exacerbates increased intracranial pressures and negatively affects perfusion pressure and cerebral blood flow. Critical care nurses must provide coordinated and effective interventions to maintain normothermia without precipitating shivering immediately after acute neurological injury in pediatric patients. To improve hyperthermia management in a 40-bed pediatric intensive care unit, an interdisciplinary pediatric critical care team developed, implemented, and evaluated a targeted temperature management protocol. The project was guided by the organization's plan-do-study-act quality improvement process. Quality improvement was assessed retrospectively using electronic medical records of patients meeting eligibility criteria. Samples of pediatric patients who received temperature interventions were compared before and after protocol implementation. The protocol included environmental, pharmacological, and body surface cooling device interventions, as well as use of a bedside shivering assessment scale and stepwise interventions to prevent and control shivering. Before implementation of the targeted temperature management protocol, 64% of patients had documented temperatures higher than 37.5 °C, and body surface cooling devices were used in 10% of patients. After protocol implementation, more than 80% of patients had documented temperatures higher than 37.5 °C, and body surface cooling devices were used in 62% of patients. Four patients (6%) before and 5 patients (31%) after protocol implementation were treated with body surface cooling without requiring use of neuromuscular blockade. Creation and implementation of a targeted temperature management protocol increased nurses' documented use of body surface cooling to manage hyperthermia in pediatric intensive care unit patients with acute neurological injury.

Temperature Management in Neurological and Neurosurgical Intensive Care Unit.

Temperature Management in Neurological and Neurosurgical Intensive Care Unit.

Safety and Feasibility of a Novel Transnasal Cooling Device to Induce Normothermia in Febrile Cerebrovascular Patients.

Inducing normothermia with surface cooling temperature modulating devices (TMDs) is cumbersome and often associated with significant shivering. We tested the safety and feasibility of a novel transnasal evaporative cooling device to induce and maintain normothermia in febrile patients following ischemic and hemorrhagic stroke. A single-center study utilizing the CoolStat® transnasal cooling device was used to achieve core temperature reduction in mechanically ventilated stroke patients with fever (T ≥ 38.3C) refractory to acetaminophen by inducing an evaporative cooling energy exchange in the nasal turbinates thru a high flow of dehumidified air into the nasal cavity and out through the mouth. Continuous temperature measurements were obtained from tympanic and core (esophageal or bladder) temperature monitors. Safety assessments included continuous monitoring for hypertension, tachycardia, and raised intracranial pressure (when monitored). Otolaryngology (ENT) evaluations were monitored for any device-related nasal mucosal injury with a pre- and post-visual examination. Shivering was assessed every 30min using the Bedside Shivering Assessment Scale (BSAS). Duration of device use was limited to 8h, at which time patients were transitioned to routine care for temperature management. Ten subjects (median age: 54years, BMI: 32.5kg/m2, 60% men) were enrolled with normothermia achieved in 90% of subjects. One subject did not achieve normothermia and was later refractory to other TMDs. Median baseline temperature was 38.5 ± 0.1C, with a reduction noted by 4h (38.5 ± 0.1 vs 37.3 ± 0.8, P < 0.001) and sustained at 8h (38.5 ± 0.1 vs 37.1 ± 0.7, P = 0.001). Time to normothermia was 2.6 ± 1.9h. The median BSAS was 0 (range 0-1) with only 4 episodes necessitating meperidine across 76h of study monitoring. No treatment was discontinued due to safety concerns. ENT evaluations noted no device-related adverse findings. Inducing normothermia with a novel transnasal TMD appears to be safe, feasible and not associated with significant shivering. A multicenter trial testing the ability of the CoolStat to maintain normothermia for 24h is currently underway.

Reliability and validity of methods in the assessment of cold-induced shivering thermogenesis

PurposeTo compare two analytical methods for the estimation of the shivering onset inflection point, segmental regression and visual inspection of data, and to assess the test–retest reliability and validity of four metrics of shivering measurement; oxygen uptake (V̇O2), electromyography (EMG), mechanomyography (MMG) and bedside shivering assessment scale (BSAS).MethodsTen volunteers attended three identical experimental sessions involving passive deep-body cooling via cold water immersion at 10 °C. V̇O2, EMG, and MMG were continuously assessed, while the time elapsed at each BSAS stage was recorded. Metrics were graphed as a function of time and rectal temperature (Tre). Inflection points for intermittent and constant shivering were visually identified for every graph and compared to segmental regression.ResultsExcellent agreement was seen between segmental regression and visual inspection (ICC, 0.92). All measurement metrics presented good-to-excellent test–retest reliability (ICC’s > 0.75 and 0.90 respectively), with the exception of visual identification of intermittent shivering for V̇O2 measurement (ICC, 0.73) and segmental regression for EMG measurement (ICC, 0.74). In the assessment of signal-to-noise ratio (SNR), EMG showed the largest SNR at the point of shivering onset followed by MMG and finally V̇O2.ConclusionsSegmental regression provides a successful analytical method for identifying shivering onset. Good-to-excellent reliability can be seen across V̇O2, EMG, MMG, and BSAS, yet given the observed lag times, SNRs, along with known advantages/disadvantaged of each metric, it is recommended that no single metric is used in isolation. An integrative, real-time measure of shivering is proposed.

Abstract 104: Metabolic Effect of Temperature Manipulation in Healthy Individuals

Introduction: Temperature manipulation to decrease metabolism is commonly after acute brain injury. Preclinical data suggest metabolism decreases 7-8% for each degree C drop in core temperature. We hypothesized similar results would be found in healthy individuals. Methods: Following informed consent and physical screening, we administered a 1mcg/kg bolus of dexmedetomidine followed by 20cc/kg of cold (4C) saline bolus. We cooled subjects using surface pads (emcools (Austria)). Dexmedetomidine infusion was titrated to effect (max dose &lt;1.5mcg/kg/hr). We recorded vital signs, Richmond Agitation Sedation Scale, Bedside Shivering Assessment Scale and sensation of cold every 15 minutes. We measured resting metabolism at baseline and after each 1 C decrease in temperature thereafter using indirect calorimetry and a ventilated canopy system. We analyzed data using analysis of variance. Results: Median age in the 9 enrolled subjects was 30 (SD 10) years and most (78%) were male. Median height was 173 (IQR 168, 180) cm and median weight was 77 (IQR 72, 83) kg. Baseline VO2 was 3.4 (IQR 3.0, 3.8) ml/kg/min and baseline energy expenditure was 1692 (IQR 1579, 1845) kcal/day. Both VO2 and energy expenditure decreased with core temperature (p=0.017 and p=0.027) (Table). Conclusion: Metabolic rate decreases with core temperature manipulation. The largest change occurs between 37C and 36C with smaller changes thereafter.

The EMCOOLs surface cooling system for fever control in neurocritical care patients: A pilot study

ObjectivesFever occurs in up to 50% of critically-ill patients with acute neurological injury. Small temperature elevations have been correlated with increased morbidity and mortality in this patient population. We sought to evaluate a novel single-use surface cooling system for the treatment of fever in patients with acute brain injury. Patients and MethodsWe conducted a retrospective analysis of a prospective product evaluation using the EMCOOLS Flex.Pad™ system for acute fever (≥38.3 °C) in our 16-bed neuro-ICU. Four refrigerated pads (−18 °C) were applied to the chest, back, and anterior thighs. Core temperature (bladder) was continuously recorded over 4 h, and the highest Bedside Shivering Assessment Scale (BSAS) score was recorded hourly. ResultsTwelve subjects were included in the analysis. Mean age was 55 ± 9 years, 9 patients were men, and mean weight was 85 ± 12 kg. The most common primary diagnoses were subarachnoid (N = 5) and intracerebral (N = 4) hemorrhage. Application of the EMCOOLS system resulted in a linear 1.3 ± 0.6 °C drop (T0avg = 38.9 ⁰C, T90avg = 37.6 ⁰C, P = 0.0032) in mean temperature over 90 min, followed by a plateau with only one subject rebounding to >38 °C within 4 h. Normothermia (<38.0 ⁰C) was achieved in all but one patient (92%) in an average of 65 min. Comatose patients displayed a non-significantly higher degree of cooling at 90 min than did awake subjects (ΔTcoma = 1.74 °C vs ΔTawake = 0.74 °C hr−1, P = 0.067). There was no observed skin irritation upon removal of the device for any patients. ConclusionThe EMCOOLs system is a well-tolerated, safe and effective short-term intervention for control of fever in neurological patients. Future studies are needed to compare efficacy of the EMCOOLs to other devices and interventions.

The effect of operating room active warming intervention on maternal hypothermia after planned cesarean

Objective To explore the effect of operating room active warming intervention on maternal hypothermia after planned cesarean. Methods According to the random number table method, from December 2016 to December 2017, 92 patients after heart failure were divided into the control group of 45 patients and the experimental group with 47 patients. Patients in the control group were conducted with the routine warming intervention, while warmed IV fluids combined with forced-air warming as active warming intervention was processed in the experimental group. The core temperature, the incidence of hypothermia, bedside shivering assessment scale, thermal comfort scores and new-born Apgar score between the two groups of patients were compared. Results Compared with the control group, the field of core temperature were significantly higher than those in the control group (F=5.96, P 0.05). Conclusion Operating room active warming intervention may have a beneficial effect on maternal hypothermia after planned cesarean, but the relevant efficacy was not shown in thefield of Apgar score. Key words: Active warming intervention; Cesarean section; Maternal hypothermia

Continuous surface EMG power reflects the metabolic cost of shivering during targeted temperature management after cardiac arrest

AimShivering may interfere with targeted temperature management (TTM) after cardiac arrest, contributing to secondary brain injury. Early identification of shivering is challenging with existing tools. We hypothesized that shivering detected by continuous surface sEMG monitoring would be validated with calorimetry and detected earlier than by intermittent clinical observation. MethodsThis prospective observational study enrolled a convenience sample of comatose adult cardiac arrest patients treated with TTM at 33 °C. Clinical shivering was monitored hourly using the Bedside Shivering Assessment Scale (BSAS) by bedside nurses who administered intermittent neuromuscular blockade (NMB) when BSAS ≥ 1. The research team monitored independently for shivering with BSAS every 15 min during continuous blinded monitoring of oxygen consumption (VO2) via indirect calorimetry and sEMG power during the maintenance phase of TTM. A sustained 20% increase in the 5-min rolling average of VO2 above baseline identified the Gold Standard shivering threshold (VO2-20). ResultsAmong 18 patients, clinical shivering was detected 23 times in 14 patients. Hierarchical models to predict a shiver event determined by the VO2-20 for sEMG power and BSAS revealed an AUC for sEMG power of 0.92 (95%CI = 0.88–0.95), and 0.90 (CI = 0.87–0.94) for BSAS. The optimal threshold of sEMG to predict VO2-20 was 32 decibels (dB), and this was exceeded 38 (29–56) min before nurse-detected shivering. ConclusionsShivering was detected by sEMG power earlier than by clinical assessment with BSAS, with similar accuracy compared to the indirect calorimetry gold standard. Continuous sEMG monitoring appears useful for clinical assessment and research for shivering during TTM.

Derived electromyography is an accurate measure of shivering burden during targeted temperature management

Shivering complicates targeted temperature management (TTM) by increasing metabolism, oxygen consumption, resting energy expenditure, and carbon dioxide production and is associated with lower brain tissue oxygen levels; all of these may limit the effectiveness of TTM. However, the recognition and measurement of shivering are subjective and ill-defined. The Bedside Shivering Assessment Scale (BSAS) is the only validated tool to describe the intensity of shivering. We hypothesized that the derived electromyography (dEMG) value measured by the bispectral index monitor (BIS) would agree with energy expenditure due to shivering, compared with the BSAS.

Induced Normothermia After Severe Traumatic Brain Injury: A Prospective Observational Pilot Safety and Feasibility Study

Background: Early hyperthermia following traumatic brain injury (TBI) is associated with worsened neurologic outcomes; however, eliminating fever has not been adequately studied. We sought to explore the safety and feasibility of induced normothermia using advanced fever control (AFC) in severe TBI patients. Methods: Eight patients underwent AFC with a surface cooling device for 96 hours, and four patients underwent conventional fever control (CFC). Average daily fever burden (FB) was calculated as the time and extent (°C × hours) above 37 °C. Shivering was evaluated hourly by the bedside shivering assessment scale (BSAS, 0 - 3) and BSAS &gt; 0 was treated using a stepwise protocol. Results: FB was lower for the AFC vs. CFC group: 4.0 vs. 7.0 (P = 0.2) for day 1, 4.3 vs. 7.7 (P = 0.1) for day 2, 3.6 vs. 5.3 (P = 0.5) for day 3, 4.2 vs. 4.8 (P = 0.7) for day 4 respectively. BSAS &gt; 0 developed more often in the AFC group (130 times) than the CFC group (two times). Conclusion: Induced normothermia was associated with less FB and more interventions to treat shivering compared to CFC in severe TBI patients. A large prospective randomized outcome trial of AFC vs. CFC is warranted. J Neurol Res. 2014;4(5-6):127-132 doi: http://dx.doi.org/10.14740/jnr283w

Induced Normothermia After Severe Traumatic Brain Injury: A Prospective Observational Pilot Safety and Feasibility Study

Background: Early hyperthermia following traumatic brain injury (TBI) is associated with worsened neurologic outcomes; however, eliminating fever has not been adequately studied. We sought to explore the safety and feasibility of induced normothermia using advanced fever control (AFC) in severe TBI patients. Methods: Eight patients underwent AFC with a surface cooling device for 96 hours, and four patients underwent conventional fever control (CFC). Average daily fever burden (FB) was calculated as the time and extent (°C × hours) above 37 °C. Shivering was evaluated hourly by the bedside shivering assessment scale (BSAS, 0 - 3) and BSAS > 0 was treated using a stepwise protocol. Results: FB was lower for the AFC vs. CFC group: 4.0 vs. 7.0 (P = 0.2) for day 1, 4.3 vs. 7.7 (P = 0.1) for day 2, 3.6 vs. 5.3 (P = 0.5) for day 3, 4.2 vs. 4.8 (P = 0.7) for day 4 respectively. BSAS > 0 developed more often in the AFC group (130 times) than the CFC group (two times). Conclusion: Induced normothermia was associated with less FB and more interventions to treat shivering compared to CFC in severe TBI patients. A large prospective randomized outcome trial of AFC vs. CFC is warranted. J Neurol Res. 2014;4(5-6):127-132 doi: http://dx.doi.org/10.14740/jnr283w

Interrater Reliability of the Bedside Shivering Assessment Scale

Since its early development, the Bedside Shivering Assessment Scale (BSAS) has had only initial psychometric testing. Before this instrument is incorporated into routine practice, its interrater reliability should be explored in a diverse group of practitioners. This prospective nonrandomized study used a panel of 5 observers who completed 100 paired assessments. Observers independently scored patients for shivering by using the BSAS. Kappa statistics were determined by using SAS version 9.4 with BSAS scores treated as ordinal data. A weighted kappa value of 0.48 from 100 paired observations of 22 patients indicates moderate agreement of the BSAS scores. Most of the BSAS scores were 0 or 1; dichotomizing shivering as little or no shivering versus significant shivering resulted in a kappa of 0.66 (substantial agreement). No relationship was found between timing of assessment or the role of the practitioner and the likelihood of both observers assigning the same BSAS score. The BSAS has adequate interrater reliability to be considered for use among a diverse group of practitioners.

Assessment of a Patient's Shivering

Therapeutic temperature management (TTM) is also known as therapeutic hypothermia or therapeutic temperature modulation. This therapy has become a standard of care for patients who are comatose after cardiac arrest. It is also used for comatose patients with acute liver failure and brain injury patients with persistent elevated intracranial pressure.1Patients receiving TTM therapy must be monitored for a variety of side effects including fluid and electrolyte alterations, hemodynamic instability, respiratory insufficiency, and shivering. Shivering is an involuntary response designed to generate heat and increase body temperature. It is difficult to identify but can have devastating effects in these already critically ill patients. An assessment tool, such as the Bedside Shivering Assessment Scale (BSAS), will help quickly identify patients who are shivering, and alllow for early intervention to limit the consequences of the shivering response.2

Shivering: scores and protocols

Shivering is both an anticipated consequence and, potentially, a major adverse effect of therapeutic hypothermia. Even mild hypothermia can elicit a vigorous thermoregulatory defense to maintain body temperature at the hypothalamic set point. In healthy humans, peripheral vasoconstriction is triggered at 36.5°C and shivering at 35.5°C. Temperature thresholds for vasoconstriction and shivering are often higher than normal in brain-injured patients; therefore, these thermoregulatory defenses may occur more vigorously and at higher temperatures in these individuals. Control of shivering is essential for effective cooling, as shivering fights the cooling process, makes attaining target temperature difficult, is extremely uncomfortable, and can trigger massive increases in systemic and cerebral energy consumption and metabolic demand. The first step in treatment is adequate tools to recognize shivering. The Bedside Shivering Assessment Scale is a simple, validated four-point scale that enables repeated quantification of shivering at the bedside. Therapy for shivering should ideally stop or suppress the central thermoregulatory reflex rather than just uncoupling this response from skeletal muscle contraction, as the latter approach does not mitigate the ongoing cerebral and systemic stress response. Analgo-sedation with opioids, α2-receptor agonists, or propofol is almost always effective as a last resort to prevent shivering. However, nonpharmacological strategies as first-line interventions for shivering minimize the risk of excessive sedation, which can make neurological examination difficult and increase the risk of complications. The Columbia Anti Shivering protocol has been developed with these strategies in mind, and we base our approach on prospectively collected cooling data on 213 patients who underwent 1,388 patient-days of temperature modulation. Eighty-nine patients underwent hypothermia and 124 patients underwent induced normothermia. In 18% of patients and 33% of the total patient-days, only none-sedating baseline interventions were needed. The first agent used was most commonly dexmeditomidine half the time, followed by opiates and increased doses of propofol. Younger patients, men, and lower body surface area were factors associated with increased number of anti-shivering interventions. As noted by this protocol, a significant proportion of patients undergoing temperature modulation can be effectively treated for shivering without oversedation and paralysis. Patients at higher risk for needing more interventions are younger men with decreased body surface area.

Shivering Management During Therapeutic Temperature Modulation: Nurses’ Perspective

Therapeutic temperature modulation, which incorporates mild hypothermia and maintenance of normothermia, is being used to manage patients resuscitated after cardiac arrest. Methods of modulating temperature include intravenous infusion of cold fluids and surface or endovascular cooling. During this therapy, the shiver response is activated as a defense mechanism in response to an altered set-point temperature and causes metabolic and hemodynamic stress for patients. Recognition of shivering according to objective and subjective assessments is vital for early detection of the condition. Once shivering is detected, treatment is imperative to avoid deleterious effects. The Bedside Shivering Assessment Scale can be used to determine the efficacy of interventions intended to blunt thermoregulatory defenses and can provide continual evaluation of patients' responses to the interventions. Nurses' knowledge and understanding of the harmful effects of shivering are important to effect care and prevent injury associated with uncontrolled shivering.

Association of the Bedside Shivering Assessment Scale and derived EMG power during therapeutic hypothermia in survivors of cardiac arrest

Introduction Shivering during therapeutic hypothermia (TH) after cardiac arrest (CA) is common, but the optimal means of detection and appropriate threshold for treatment are not established. In an effort to develop a quantitative, continuous tool to measure shivering, we hypothesized that continuous derived electromyography (dEMG) power detected by the Aspect A2000 or VISTA monitor would correlate with the intermittent Bedside Shivering Assessment Scale (BSAS) performed by nurses. Methods Among 38 patients treated with TH after CA, 853 hourly BSAS measurements were compared to dEMG power measured every minute by a frontal surface electrode. Patients received intermittent vecuronium by protocol to treat clinically recognized shivering (BSAS > 0). Mean dEMG power in decibels (dB) was determined for the hour preceding each BSAS measurement. dEMG and BSAS were compared using ANOVA. Results The median dEMG power for a BSAS score of 0 (no shivering) was 27 dB (IQR 26–31 dB), BSAS 1 was 30.5 dB (IQR 28–35 dB), BSAS 2 was 34 dB (IQR 30–38 dB), and BSAS 3 was 34.5 dB (IQR 32–44.25). The dEMG for BSAS ≥ 1 (shivering) was statistically different from BSAS 0 ( p < 0.0001). dEMG and BSAS correlated moderately ( r = 0.66, p < 0.001). Conclusion dEMG power measured from the forehead with the Aspect A2000 or VISTA monitor during therapeutic hypothermia correlated with the Bedside Shivering Assessment Scale. Given its continuous trending of dEMG power, the A2000 or VISTA may be a useful research and clinical tool for objectively monitoring shivering.

Metabolic benefits of surface counter warming during therapeutic temperature modulation*

To determine the impact of counter warming (CW) with an air circulating blanket on shivering and metabolic profile during therapeutic temperature modulation (TTM). A prospective observational study. An 18-bed neurologic intensive care unit. Fifty mechanically ventilated patients with brain injury undergoing TTM with automated surface and intravascular devices. Fifty indirect calorimetry (IDC) measurements with and without CW during TTM. IDC was continuously performed for 10-15 minutes at baseline with CW (phase I), off CW (phase II), and again after the return of CW (phase III). Shivering severity during each phase was scored on a scale of 0-3 using the Bedside Shivering Assessment Scale (BSAS). Resting energy expenditure (REE), oxygen consumption, and carbon dioxide production were determined by IDC; 56% were women, with mean age 61 +/- 15 years. At the time of IDC, 72% of patients had signs of shivering (BSAS >0). All measures of basal metabolism increased after removal of the air warming blanket (from phases I and II); REE increased by 27% and oxygen consumption by 29% (both p < 0.002). A one-point increase in baseline BSAS was noted in 55% (n = 23/42) of patients from phase I to phase II. In a multivariate analysis, sedative use (p = 0.03), baseline moderate to severe shivering (p = 0.04), and lower serum magnesium levels (p = 0.01) were associated with greater increases in REE between phase I and phase II of CW. Phase III of CW was associated with a reversal in the increases in all metabolic variables. Surface CW provides beneficial control of shivering and improves the metabolic profile during TTM.