A prospective, randomized, double-blinded control study on comparison of tramadol, clonidine and dexmedetomidine for post spinal anesthesia shivering / Estudo prospectivo randômico, duplo-cego e controlado comparando tramadol, clonidina e dexmedetomidina para tremores pós-raquianestesia

Abstract Introduction Shivering, a common intraoperative problem under spinal anesthesia increases the oxygen consumption considerably and is uncomfortable and distressing to the patient, anesthesiologist as well as surgeon. The present study was designed to explore the effectiveness of tramadol, clonidine and dexmedetomidine in the treatment of post spinal anesthesia shivering and to look for their adverse effects. Methods This prospective, randomized, double blinded control study was done on 90 patients who developed shivering under spinal anesthesia. They were randomly allocated into three groups with Group T receiving tramadol 1 mg.kg-1, Group C getting clonidine 1 mcg.kg-1 and Group D patients receiving dexmedetomidine 0.5 mcg.kg-1. The time taken to control shivering, recurrence rate, hemodynamic variables, sedation score and adverse effects were observed. Results Dexmedetomidine was faster in the control of shivering in 5.7 ± 0.79 minutes (min) whereas tramadol took 6.76 ± 0.93 min and clonidine was slower with 9.43 ± 0.93 min. The recurrence rate was much lower in the dexmedetomidine group with 3.3% than for clonidine (10%) and tramadol (23.3%) group. The sedation achieved with dexmedetomidine was better than clonidine and tramadol. The tramadol group had more cases of vomiting (four) and dexmedetomidine group had six cases of hypotension and two cases of bradycardia. Two of the clonidine patients encountered bradycardia and hypotension. Conclusion Dexmedetomidine is better than tramadol and clonidine in the control of shivering because of its faster onset and less recurrence rate. Though complications are encountered in the dexmedetomidine group, they are treatable.

Resumo Introdução O tremor, problema comum no período intraoperatório sob raquianestesia, aumenta consideravelmente o consumo de oxigênio, além de ser desconfortável e angustiante para o paciente, o anestesiologista e o cirurgião. O presente estudo foi concebido para explorar a eficácia de tramadol, clonidina e dexmedetomidina no tratamento de tremores pós-raquianestesia e observar seus efeitos adversos. Métodos Este estudo prospectivo, randômico, controlado e duplo-cego foi feito com 90 pacientes que desenvolveram tremores sob raquianestesia. Os pacientes foram randomicamente alocados em três grupos para receber 1 mg.kg-1 de tramadol (Grupo T), 1 mcg.kg-1 de clonidina (Grupo C) e 0,5 mcg.kg-1 de dexmedetomidina (Grupo D). O tempo necessário para controlar os tremores, a taxa de recorrência, as variáveis hemodinâmicas, os níveis de sedação e os efeitos adversos foram registrados. Resultados Dexmedetomidina foi mais rápida para controlar os tremores, com tempo de 5,7 ± 0,79 minutos (min); o tempo de tramadol foi de 6,76 ± 0,93 min; clonidina foi mais lenta, com tempo de 9,43 ± 0,93 min. A taxa de recorrência foi muito menor no grupo dexmedetomidina (3,3%) do que nos grupos clonidina (10%) e tramadol (23,3%). A sedação obtida com dexmedetomidina foi melhor do que a obtida com clonidina e tramadol. O grupo tramadol teve mais casos de vômito (quatro); o grupo dexmedetomidina teve seis casos de hipotensão e dois casos de bradicardia. Dois pacientes do grupo clonidina apresentaram bradicardia e hipotensão. Conclusão Dexmedetomidina foi melhor do que tramadol e clonidina para o controle de tremores devido ao seu início de ação mais rápido e à taxa de recorrência mais baixa. Embora complicações tenham sido observadas no grupo dexmedetomidina, elas foram tratáveis.

Dexamethasone for prevention of postoperative shivering: a randomized double-blind comparison with pethidine

Postoperative shivering is very common and followed by many problems such as increasing oxygen consumption, blood pressure, intracranial and intraocular pressure, and postoperative pain. Therefore, prevention of shivering is important, especially in elderly and ischemic heart disease patients. The goal of this study was to compare the effect of pethidine [meperidine], dexamethasone, and placebo on prevention of shivering. This double-blind clinical trial study was carried out on 120 patients who were candidates for surgery under general anesthesia. The patients were randomly divided into three groups. Induction and maintenance of anesthesia for all patients were similar. Temperature of patients was measured every 5 min interval. After induction, saline 0.9%, dexamethasone and pethidine were injected to groups a, b, and c, respectively. In recovery, patients were controlled for visible shivering. All data were statistically analyzed by analysis of variance [ANOVA] and Chi-square tests. There were no significant differences among three mentioned groups regarding gender, age, duration of surgery and anesthesia, extubation time, duration of recovery, and basic clinical characteristics. Nineteen cases [47.5%] of placebo group had postoperative shivering, whereas in dexamethasone group only four cases [10%] had shivering and the difference between the two groups was significant. Also in pethidine group, 15 cases [37.5%] had shivering and the difference with placebo group was significant [P value = 0.001]. The present study showed that pethidine and dexamethasone are effective drugs for prevention of postoperative shivering in elective surgery and the effect of dexamethasone in preventing the postoperative shivering is better than pethidine

[Comparison between intrathecal midazolam and tramadol with conventional method for postoperative pain and shivering control after elective cesarean section]

Adding new supplements when performing spinal anesthesia can increase the duration of analgesia. The aim of the present study has been to compare intrathecal midazolam and tramadol with the conventional method for postoperative pain and shivering control after elective caesarean section. In this double-blind clinical trial, 210 ASA class I, II women, aged 20-35 years, candidate for elective caesarean section were randomly allocated to three groups. All patients received hyperbaric intrathecal lidocaine and additionally group I received 2 mg subarachnoid midazolam, group II received 25 mg subarachnoid tramadol and the control group received 5cc normal saline. Postoperative pain score, the painless duration and postoperative shivering were assessed in the three groups. The mean painless duration in tramadol, midazolam and the control group were 192.5 +/- 12.2, 111.3 +/- 16.6 and 86.1 +/- 9.9 minutes, respectively [p<0.001]. The mean painless duration in the midazolam group was significantly more than two other groups and this duration in the tramadol group was also more than the control one. The mean postoperative pain score, shivering occurrence and the frequency of requested painkiller in the first 24 hours, were also compared. In the midazolam group, they were all significantly less than the two other groups. In the meanwhile, these indexes in the tramadol group were less than the control one [p<0.001]. Adding intrathecal midazolam and tramadol to lidocaine 5% in elective caesarean section can increase the painless duration and lead to a reduction in postoperative shivering. Midazolam demonstrates a stronger effect

Dexmedetomidine for the prevention of shivering during spinal anesthesia

PURPOSE: The aim of this study was to evaluate the effect of dexmedetomidine on shivering during spinal anesthesia. METHODS: Sixty patients (American Society of Anesthesiologists physical status I or II, aged 18-50 years), scheduled for elective minor surgical operations under spinal anesthesia with hyperbaric bupivacaine, were enrolled. They were administered saline (group C, n = 30) or dexmedetomidine (group D, n = 30). Motor block was assessed using a Modified Bromage Scale. The presence of shivering was assessed by a blinded observer after the completion of subarachnoid drug injection. RESULTS: Hypothermia was observed in 21 patients (70 percent) in group D and in 20 patients (66.7 percent) in group C (p = 0.781). Three patients (10 percent) in group D and 17 patients (56.7 percent) in group C experienced shivering (p = 0.001). The intensity of shivering was lower in group D than in group C (p = 0.001). Time from baseline to onset of shivering was 10 (5-15) min in group D and 15 (5-45) min in group C (p = 0.207). CONCLUSION: Dexmedetomidine infusion in the perioperative period significantly reduced shivering associated with spinal anesthesia during minor surgical procedures without any major adverse effect during the perioperative period. Therefore, we conclude that dexmedetomidine infusion is an effective drug for preventing shivering and providing sedation in patients during spinal anesthesia.

Effects of tramadol on shivering post spinal anesthesia in elective cesarean section

Post operative shivering is a complication commonly observed in post spinal anesthesia. For prevention and treatment of this complication different drugs are used. This study evaluated the effects of tramadol for post operative shivering prevention in parturients carried out by help of spinal anesthesia [SA] for cesarean section. In this randomized double blind cross-sectional study, 90 patients who were candidates for cesarean section with American Society of Anesthesiologist [ASA] I or II, from April 2005 until February 2006 were randomly allocated to one of two groups [study and control]. All patients underwent spinal anesthesia. Near the end of operation, 1mg/kg tramadol in 20ml [diluted by normal saline] to study group and 20ml of normal saline to control group was slowly injected intravenously. Patients were evaluated regarding their hemodynamic signs, arterial oxygen saturation percentage, oral temperature, presence and intensity of shivering and nausea and vomiting. Collected data was analysed by using of Chi-square test. Thirty nine patients [86.6%] in control group had shivering, while only four patients [8.8%] in study group had shivering. Thirty three patients [73.3%] of control group experienced moderate shivering and six patients [13.3%] experienced mild shivering. In study group two patients [50%] had moderate shivering and two patients [50%] experienced mild shivering. Neither group experienced severe shivering. Therefore between the two groups a significant difference [P<0.001] was seen. There were no significant differences between the two groups according to heart rate, systolic and diastolic blood pressure, oxygen saturation percentage, nausea and vomiting and body temperature of the patients. Tramadol is an effective drug in prevention of post spinal anesthesia shivering. In addition, this does not lead to any hemodynamic complications. As such drug is safe and effective for prevention of post spinal anesthesia shivering

Intramuscular ketamine for prevention of postanesthesia shivering in children

To compare the effects of intramuscular ketamine with pethidine and placebo on post operative shivering in children undergoing tonsillectomy. A prospective randomized double-blind study was conducted at King Abdulaziz Naval Base Hospital, Jubail, Kingdom of Saudi Arabia, from November 2006 to October 2007. One hundred and twenty children [American Society of Anesthesiologists Grade 1, aged 5-12 years] were enrolled. Children were randomly allocated to receive ketamine 1 mg/kg [group K, n=40], or pethidine 0.5 mg/kg [group P, n=40], or normal saline [group S, n=40] intramuscularly just after induction of general anesthesia. Hemodynamic parameters, oxygen saturation and tympanic temperature were measured and recorded before induction of anesthesia and at regular intervals thereafter. An investigator blinded to the treatment group, graded postoperative shivering using a 5 point scale. The number of patients shivering on arrival to the recovery room and at 10 and 20 minutes after operation were significantly less in groups K [1,1,1] than in group S [19,12,17]. No patient that received pethidine shivered. The time to first analgesic requirement in group S was shorter than groups K and P [p=0.001]. The study indicates that the use of a prophylactic low dose ketamine was found to be effective in preventing post anesthesia shivering in children undergoing tonsillectomy. Ketamine may have at least theoretical advantages over pethidine as regard respiratory depression, nausea, and vomiting

Intravenous clonidine reduces the frequency and severity of shivering and pain after urological surgeries

This study aimed to evaluate the therapeutic yield of ketamine and clonidine in patients assigned for various urological surgeries. The study comprised 90 patients; 54 males and 36 females with mean age of 43.5 +/- 8.3 years. Patients were randomly allocated into 3 equal groups to receive saline [Control group]; ketamine 0.5 mg/kg or clonidine 3 microg/kg injected intravenously 20 min before the end of surgery. Anesthetic management of all patients was standardized and recovery times were measured from completion of wound dressing to eligibility for discharge from the recovery room; defined as a modified Aldrete score of >/= 9. Post-anesthetic shivering [PAS] was graded on admission to the post-anesthetic recovery room [T0], and 10 min [T10], 20 min [T20] and 30 min [T30] thereafter using a four-point scale. Pain was assessed using a 0-10cm visual analogue scale [VAS] hourly for 6 hours and then 3-hourly for the first 24-hrs after surgery, VAS scores were expressed collectively as 3-hours VAS score. Meperidine, 20 mg IV injection was given for PAS >/= 2 and/or VAS >/= 4. Any possible side-effects of the study drugs were recorded. Patients received clonidine consumed longer time till had Aldrete score of >/= 9 that had significant compared to saline and non-significant compared to ketamine group with a non-significantly longer time with ketamine compared to saline. No PAS was recorded in 40 patients [44.4%] with a total frequency of PAS of 55.6%. Clonidine significantly reduced the frequency and score of PAS with a significant reduction of the need for and the numbers of requests of PAS rescue treatment in comparison to saline and ketamine with a significant difference in favor of ketamine. Clonidine significantly reduced VAS scores and spared the need for rescue analgesia compared to both placebo and ketamine with a significant difference in favor of ketamine. It could be concluded that clonidine administration prior to end of surgery provided superior postoperative outcome compared to ketamine and manifested as reduced frequency and severity of both PAS and pain with significant reduction of the need for rescue treatment

Intravenous dexmedetomidine is efficient prophylaxis against post-anesthesia shivering with rescue-treatment sparing effect: a comparative placebo-controlled study versus meperidine and ketamine

This study aimed to evaluate the effect of dexmedetomidine and ketamine on the frequency and severity of post-anesthetic shivering [PAS] in comparison to meperidine as negative and saline as positive control drugs. The study comprised 80 patients assigned to undergo abdominal or pelvic surgery under general anesthesia. Patients were randomly allocated into 4 equal groups [n=20] received intravenous injection of either saline [Group S], meperidine 20 mg [Group M], ketamine 0.5 mg/kg [Group K] or dexmedetomidine 1 micro g/kg [Group D], all drugs were given as a 10-ml injection, 20 minutes prior to the end of surgery. In postanesthesia recovery unit [PACU], all patients were monitored noninvasively for heart rate, blood pressure, oxygen saturation and core temperature measured at the tympanic membrane using an ear thermometer [Thermoscan IRT 3020; Braun, Kronberg, Germany]. Post-anesthetic recovery was scored using the Observer's Assessment of Alertness/ Sedation [OAA/S] score on arrival to PACU. The severity of PAS was evaluated using five grades scale; on admission to PACU [T0], 10 min [T10], 20 min [T20] and 30 min [T30] after admission. Nefopam was given 10 mg IV at PAS score of 2. Any possible side-effects of the study drugs were recorded. In group S, 18 patients had PAS; 15 required treatment but 3 patients did not require and the other 2 patients had no PAS. In group K, 11 patients had PAS score of zero, 6 patients had PAS scored one and the other 3 patients had PAS scored >/=2 and required treatment. Only 3 patients; 1 in group M and 2 in group D had PAS scored one but no patient required treatment. There was a significant difference in the frequency of PAS and need for treatment between groups M and D compared to both group S and K. Moreover, there was a significant difference in the frequency of PAS and need for treatment between groups K and S. Eight patients [10%] had postoperative nausea and vomiting with a nonsignificant difference between studied groups and 2 patients in group K had mild hallucinations. It could be concluded that dexmedetomidine [1[micro]g/kg] intravenous injection 20 minutes prior to end of surgery significantly reduced post-anesthetic shivering and completely spared the use of postoperative rescue medications

Effect of amino acids infusion on thermoregulatory response and blood loss during spinal anesthesia

Intravenous amino acids infusion during general anesthesia prevents decreases in core temperature resulting from increased energy expenditure and heat accumulation. Mild hypothermia may increase surgical bleeding. We studied the effect of amino acids infusion on changes in core temperature and blood loss during spinal anesthesia in patients undergoing hip surgery. Fifty patients were divided into two equal groups. Group 1 patients received an amino acids infusion at a rate of 2 ml /kg/ hr., corresponding to 4kjkg-1h-1, started 1 hr before spinal anesthesia and two hours during surgery. Group 2 patients received normal saline for the same period. Mean blood pressure, heart rate, tympanic membrane core temperature, forearm-fingertip temperature gradient and mean skin temperature, coagulations profile were monitored during the study period and blood loss was measured. Changes in mean arterial pressure and heart rate did not differ significantly between the two groups during the study period. Mean final core temperature 120 min. after induction of spinal anesthesia was 34.37 [SD 0.37] °C in the saline group and 36.02 [SD 0.21]°C in the amino acid group [p < 0.05] The thermal vasoconstriction threshold was increased in the amino acid group [36.1 +/- 0.1 °C] compared with the saline group [34.0 +/- 0.1 °C]. Blood loss during surgery was significantly larger in the saline group [704.88 +/- 175.9 ml] than in the amino acids group [553.2 +/- 107.14] [p < 0.05]. Platelet counts decreased significantly in both groups immediately and first day after surgery [p < 0.05]. However, there were no differences in coagulation values between the two groups. The amino acids infusion before and during spinal anesthesia was able to prevent the occurrence of intraoperative hypothermia and reduces blood loss without significant effect on coagulation profile

Comparative study between intrathecal fentanyl and meperidine to decrease shivering during surgery and cesarean delivery under spinal anesthesia

Shivering associated with spinal and epidural anesthesia is common, occurring in up to 56.7% of patients. Shivering is uncomfortable for the patient and interferes with monitoring of electrocardiogram, blood pressure, and oxygen saturation. Those effects are particularly troublesome in the obstetrical population. The aim of this work is to determine whether meperidine [0.2mg/Kg],added to a bupivacaine, decrease the incidence an intensity of shivering during spinal anesthesia. Sixty patients were enrolled in this study, scheduled for non emergent surgery under spinal anesthesia. Patients were randomly devided into three groups: group I consisted of 20 cases with spinal anesthesia of hyperbaric bupivacaine [0.5%, 12.5 mg, fentanyl 50 ug], group II consisted of 20 cases with spinal anesthesia meperidine was added [0.2mg/kg], group III consisted of 20 cases with spinal anesthesia, with an equivalent volume of normal saline, in CS Apgar score was recorded at 1, 5 and 10 minutes. The Results Indicated that the incidence of shivering was less in meperidine group there was 5 of 20 versus 15 Of 20 in fentanyl group and 19 of 20 in control group, with P value <0.02. There was no difference between groups as regard Apgar score. It was concluded that intrathecal use of meperidine [0.2mg/kg] reduces the incidence and intensity for shivering associated with interathecal anesthesia

comparison among Doxapram, Nulbuphine and Meperidine for treatment of postanesthetic shivering

Postanesthetic shivering [PS] is distressing for patients and may induce a variety of complications. We carried out our study to evaluate the value of Doxapram, Nulbuphine and Meperidine for treating PS. 80 patients were included in the study who undergone general anesthesia for routine general orthopedic or gynecologic surgery and developed shivering within 10 minutes of admission to the recovery room where they are divided into 4 groups; each of 20 patients classified as follows: Group 1 [n = 20] placebo saline group [received i.v. saline]; Group 2 [n = 20] Doxapram group [received 1.5 mg/kg i.v.] Group 3 [n = 20] Nulbuphine group [received 0.08 mg/kg i.v.]; Group 4 [n=20] Meperdine group [received 0.4 mg/kg i.v.]. Treatment that stopped shivering was considered to have been successful. The results demonstrated that 5 min. after treatment with Doxapram, Nulbuphine and Meperidine provided rapid and potent anti-shivering effect on PS, with high response rate of 75%, 80% and 85%, respectively compared with those of placebo saline [0%] [p < 0.01]. 15 minutes after injection, the response rates of Doxapram, Nulbuphine and Meperidine were 80%, 85% and 90%, respectively compared with 15% in the saline group. 30 minutes after injection, the response rates of Doxapram, Nulbuphine and Meperidine 85%, 90% and 95%, respectively compared with 20% in the saline group. We concluded that nulbuphine and meperidine prevent PS but meperidine is superior to both Doxapram and Nulbuphine and Nulbuphine provides a similar rapid and potent shivering effect so it may be an alternative to meperidine for treating postanesthetic shivering

Prevention of postanesthetic shivering using nefopam and clonidine, a double-blind, placebo controlled study

Recovery from anesthesia is frequently accompanied by shivering [incidence up to 65 percent]. Post-anesthetic shivering [PAS] can exacerbate postoperative pain and also may induce many complications. Intraoperative hypothermia is the major risk factor from postanesthetic shivering, but shivering can occur in patients who are normothermic at the end of surgery. Various drugs and maneuvers were used to reduce or stop PAS. The aim of this study is to evaluate the effect of nefopam, and clonidine as inhibitors of PAS in comparison with placebo. Sixty patients of both sexes, ASA 1 and II. aged 17 to 60 years were scheduled for elective surgical procedures under general anesthesia. All patients received, midazolam [premedication] 0.04 mg/Kg. Then fentanyl [1 micro g/Kg], Thiopental [5mg/Kg] and atracurium [0.5 mg/Kg], endotracheal intubations, controlled ventilation with a mixture of isoflurane [1.1-2 percent] and N[2]O 60 percent in oxygen. End-tidal CO2 is kept at 30-35 mmHg. Warmed i.v. solutions were not used and patients were not actively warmed. Temperature was monitored by the use of nasopharyngeal thermocouple probe and temperature registered at 15 min, 30 min, and 60 min after exctubation. At the end of surgery, using a double-blind random protocol patients given either saline 0.9 percent [placebo], nefopam, 0.15 mg/Kg [nefopam group] or clonidine, 1.5 micro g/Kg [clonidine group]. Post anesthetic shivering [PAS] was assessed at 5 min.,15 min., 30 min and 60 min after extubation using 5-point scale. Recovery time, H.R. Mean arterial blood pressure and oxygen saturation are also assessed. The incidence of post-anesthetic shivering was lower in nefopam group [10 percent], and in clonidine group [20 percent]. than in placebo group which was about 75 percent. Recovery time was prolonged in clonidine group [12.2 min], than in nefopam group [7.9 min], while in placebo group it was 6 min Nefopam and clonidine are both effective for prevention of PAS but nefopam may be a better drug to use than clonidine

The use of tramadol hydrochloride in the treatment of post-anesthetic shivering.

Tramadol at the dosage of 1 mg per kg body weight was given intravenously to 110 adult patients who developed postoperative shivering. All patients were cured of the shivering after 45 seconds to 6 minutes. Seventy-four per cent stopped within 2 minutes after the injection. There were five patients who had recurrence of shivering after 10 to 30 minutes and this was easily stopped by another dosage of the drug. There were very few minor side effects and they required no medical treatment.