Lumbar versus thoracic epidural buprenorphine for postoperative analgesia following coronary artery bypass graft surgery

BACKGROUND: Thoracic epidural analgesia (TEA) is reported to provide effective analgesia following cardiac surgery. We compared the effect of buprenorphine (BN) through the lumbar and thoracic epidural routes for postoperative analgesia following coronary artery bypass graft surgery (CABG). METHODS: Forty patients with normal left ventricular ejection fraction scheduled for CABG were randomly divided into two groups, the TEA group (n = 19) and the lumbar epidural analgesia (LEA) group (n = 20). For postoperative pain relief they received epidural BN 0.15 mg at the first demand for pain relief following extubation. A top-up dose of BN 0.15 mg was administered in cases where visual analogue scale (VAS) score was > 3 at 1 h after first dose. Subsequent breakthrough pain was treated with 30 mg intramuscular ketorolac tromethamine (ketorolac). Pain assessed by VAS score on a 0-10 scale, respiratory rate, FEV1, FVC, mean arterial blood pressure, cardiac index, PaO2 and PaCO2 were measured at frequent intervals. Side effects of epidural opioids were noted. RESULTS: Both groups were comparable in demographic characteristics, had similar VAS scores from 1 to 24 h postoperatively, required similar amounts of intramuscular ketorolac for break-through pain and had comparable pulmonary functions and side effects. CONCLUSION: This study shows that BN by the lumbar epidural route for analgesia after CABG compares favourably with the same drug through the thoracic route in terms of quality of analgesia and incidence of side effects.     

Similar pain scores after early and late extubation in heart surgery with cardiopulmonary bypass

OBJECTIVE: To investigate if early extubation, 2 hours after surgery, would result in more postoperative pain or in an increased use of opioid analgesics compared with late extubation, 6 hours after surgery. DESIGN: Prospective, randomized study. SETTING: Intensive care unit, university hospital. PARTICIPANTS: Sixty patients undergoing cardiac surgery with cardiopulmonary bypass. INTERVENTIONS:Patients were randomized into 2 groups: extubation at about 2 (early) or 6 (late) hours. Anesthesia was based on propofol and remifentanil. There was no epidural analgesia and no local anesthesia in the wound. A bolus of the opioid ketobemidone was administered toward the end of surgery followed by a continuous infusion. MEASUREMENTS AND MAIN RESULTS: Pain, provoked during deep breathing or coughing, evaluated with a visual analog scale (VAS) going from 0 to 10, was measured after extubation, and at 8 and 16 hours after surgery. Unprovoked pain was measured hourly. If VAS was greater than 3, the infusion rate was increased and a bolus of ketobemidone was given. Three patients in the late group were excluded because of incomplete data. Pain did not differ between the early and late groups at any time. In all patients, 21 never scored >3, 11 scored >3 once, and 25 scored >3 more than once. Nine patients had 1 score >5. The amount of ketobemidone was similar in both groups. CONCLUSIONS: Early extubation had no negative effect on the quality of postoperative pain control and was not followed by an increased use of analgesics.     

Comparison of the analgesic efficacy of ketobemidone and morphine for management of postoperative pain in children: a randomized, controlled study

BACKGROUND: Ketobemidone has been used as an analgesic for postoperative pain in children, but to our knowledge the effect and occurrence of adverse effects of ketobemidone compared to morphine is not known. The aim was to determine if the analgesic potency and the occurrence of adverse effects of ketobemidone differ from morphine when administered to children, as measured by patient-controlled analgesia consumption (PCA) for postoperative pain. METHODS: Sixty healthy children, aged 6 to 16 years, scheduled for elective surgery were randomized to receive either ketobemidone (Ke) 1 mg ml(-1) or morphine (Mo) 1 mg ml(-1) for postoperative pain through PCA. Drug consumption (microg kg(-1) h(-1)), the number of PCA doses, pain intensity, and adverse effects were recorded at regular intervals. RESULTS: Data on total drug consumption were based on 26 children in the Ke group and 28 in the Mo group. A non-statistically significant difference for total mean consumption of ketobemidone (18.6 microg kg(-1)h(-1)) and morphine (23.2 microg kg(-1)h(-1)) was obtained. The mean dose ratio (Mo/Ke) was 0.80 and the median was 0.94. Children's characteristics, loading dose, PCA doses, VAS scores, and adverse effects showed no significant differences between the groups. CONCLUSION: The analgesic potency and adverse effects of ketobemidone are similar to morphine when used for postoperative pain management in children.     

Fast-track coronary artery bypass grafting surgery under general anesthesia with remifentanil and spinal analgesia with morphine and clonidine

OBJECTIVE: Effective postoperative analgesia is a critical part of fast-track cardiac surgery. This study compared the postoperative analgesic effect of fast-track anesthesia with remifentanil and spinal morphine and clonidine with that of sufentanil anesthesia followed by patient-controlled administration of intravenous morphine. DESIGN: Prospective, blinded, randomized study. SETTING: Single private institution. PARTICIPANTS: Forty patients selected for coronary artery bypass graft surgery allocated randomly into 2 groups. INTERVENTIONS: General anesthesia was performed with etomidate, isoflurane, cisatracurium, and either remifentanil (0.10-0.25 microg/kg/min) or sufentanil (up to 3.5 microg/kg). In the remifentanil group, patients received spinal morphine (4 microg/kg) and clonidine (1 microg/kg) before induction. Postoperatively, patients in both groups were connected to an intravenous patient-controlled analgesia (PCA) morphine pump that delivered a 1-g bolus with a 7-minute lockout interval. MEASUREMENTS AND MAIN RESULTS: Patients were evaluated for pain on a visual analog scale (VAS), at rest and on deep breathing, and for intravenous PCA morphine consumption during 24 hours. The intravenous PCA morphine 24-hour cumulative dose was lower in the fast-track than in the control group (15.8+/-12.6 v 32.7+/-22.3 mg, p<0.05). Before extubation, VAS scores were higher in the fast-track group, but after they were lower both at rest and during deep breathing. Extubation delay was shorter in the fast-track group (156.5+/-46.1 v 272+/-116.4 minutes, p<0.05). CONCLUSION: The combination of anesthesia with remifentanil and spinal analgesia with morphine and clonidine produces effective analgesia after coronary artery surgery and a rapid extubation time.     

The effects of single-dose tramadol on post-operative pain and morphine requirements after coronary artery bypass surgery

AIM: To investigate the effects of a single dose of tramadol administered prior to extubation on post-operative pain and morphine consumption after coronary artery bypass surgery. METHODS: Patients were randomized post-operatively into two groups (group T, n= 30; group P, n= 30). The technique of anaesthesia was standardized for all patients. The patients in group T received intravenous tramadol, 1 mg/kg, and the patients in group P received 2 ml of saline 0.9%, both approximately 1 h before extubation. After extubation, all patients were allowed to use the morphine patient-controlled analgesia (PCA) device for 24 h post-operatively. Post-operative data were recorded in the cardiac intensive care unit at 30 min, 1 h, 2 h, 4 h, 12 h and 24 h after extubation by the same anaesthesiologist, who had no knowledge of the groups, and the side-effects were also evaluated. RESULTS: In group P, the visual analogue scale (VAS) scores were found to be higher 30 min (P < 0.01), 1 h (P < 0.01), 2 h (P < 0.01) and 4 h (P < 0.05) after extubation. The patient comfort scores were higher in group T 30 min (P < 0.01), 1 h (P < 0.05), 2 h (P < 0.01) and 4 h (P < 0.01) after extubation. The total morphine consumption was higher in group P at all evaluation times (P < 0.01), and the numbers of PCA demands and boluses were also higher in group P (P < 0.01). CONCLUSIONS: The study demonstrated that a single dose of tramadol administered prior to extubation following coronary artery bypass surgery is associated with a decrease of up to 25% in morphine consumption, a decrease in the VAS scores and an improvement in patient comfort within the first 4 h post-operatively.     

Rectal indomethacin reduces postoperative pain and morphine use after cardiac surgery

PURPOSE: To evaluate the combination of rectal indomethacin with patient controlled intravenous morphine analgesia (PCA) on postoperative pain relief and opioid use after cardiac surgery. METHODS: With institutional ethics approval, 57 consenting adults undergoing elective aortocoronary bypass surgery were randomly assigned preoperatively in a double-blind fashion to receive either placebo (n = 26) or indomethacin 100 mg suppositories (n = 31), 2-3 hr postoperatively, and 12 hr later. Both groups utilized PCA morphine. Pain scores in the two treatment groups were assessed on a 10-cm visual analogue scale (VAS) (at rest and with cough) at 4, 6, 12, 18 and 24 hr after initial dosing, and were analyzed through a 2 x 5 repeated measures of variance. The 24 hr analgesic consumption, 12 and 24 hr chest tube blood loss, and time to tracheal extubation were also recorded, and compared for the two treatment arms through Student's t test on independent samples. RESULTS: Postoperative morphine consumption in the first 24 hr was 38% less in the indomethacin group (22.40 +/- 12.55 mg) than the placebo group (35.99 +/- 25.84 mg), P = 0.019. Pain scores, measured with a VAS, were 26% to 66% lower in the indomethacin vs placebo group at rest (P = 0.006), but not with cough, for all times assessed. There was no difference in blood loss (at 12 hr) or time to tracheal extubation for both groups. CONCLUSION: The combination of indomethacin with morphine after cardiac surgery results in reduced postoperative pain scores and opioid use without an increase in side effects.     

Remifentanil patient-controlled analgesia following cardiac surgery

Background:  Remifentanil is increasingly used as a component of cardiac anaesthesia. Following cardiac surgery remifentanil is often substituted for alternative opioids on the intensive care unit. We were interested to evaluate postoperative continuation of remifentanil in the form of remifentanil patient control analgesia (RPCA) for those patients who received intraoperative remifentanil. The objectives of this study were to assess the safety, efficacy and feasibility of the RPCA.
Methods:  Ten patients who received an intravenous infusion of remifentanil perioperatively for coronary artery bypass graft surgery (CABG) had their remifentanil infusion converted to RPCA following extubation on the intensive care unit. Remifentanil patient control analgesia delivered an initial background infusion consistent with the infusion rate at extubation and with a bolus facility of 50 µg administered over 5 min followed by a 5-min lockout. Data collection included sedation and pain scores, respiratory rate, arterial blood gases, number of successful/unsuccessful attempts and the background infusion rate for each subject over a period of 12 h following extubation.
Results:  The data from nine male and one female patient were analyzed by using SPSS11 for Windows. During the study period the patients achieved adequate pain control and made more RPCA attempts at lower background infusion rates. No episodes of apnoea, SpO₂ less than 95% or a rise in PaCO₂ greater than 6.5 kPa were observed.
Conclusion:  Remifentanil patient control analgesia with a background infusion was effective and safe for postoperative pain relief in this group of spontaneously breathing ICU patients following cardiac surgery.     

Epidural analgesia with bupivacaine reduces postoperative paralytic ileus after hysterectomy

This study was undertaken to compare the effects of postoperative bupivacaine epidural analgesia with those of intermittent injections of ketobemidone (a synthetic opioid) on postoperative bowel motility in patients who had had hysterectomies. The epidural group (N = 20) received continuous epidural anesthesia with bupivacaine postoperatively for 26-30 hours and the control group (N = 20) received intermittent injections of ketobemidone for postoperative pain relief. Postoperative bowel movements and propulsive colonic motility were estimated from the first passage of flatus and feces and by following radiopaque markers by serial abdominal radiographs. In the epidural group, the times for first passing of flatus (31 +/- 22 hours; mean +/- SD) and feces (70 +/- 44 hours) were significantly shorter than in the control group (flatus 58 +/- 14 hours and feces 103 +/- 26 hours). The average position of the markers was significantly more distally in the epidural group immediately after operation and the markers continued to move forward during the first postoperative day. In the control group, the markers did not move during this period. The results demonstrate that postoperative bowel peristalsis returned earlier in the patients given epidural analgesia with bupivacaine for pain relief than in patients given a narcotic.     

术中负荷剂量曲马多对术后吗啡PCA效果的影响

目的　研究术中负荷剂量曲马多的使用对术后吗啡病人自控镇痛 (PCA)效果的影响。方法　 6 0例腹部手术患者 ,采用随机、双盲、对照试验的方法于手术结束前静脉给予生理盐水 (对照组 )、1mg/kg曲马多或 2mg/kg曲马多。术后使用吗啡静脉PCA进行镇痛。观察术后镇痛效果及不良反应。结果　曲马多组与对照组比较 ,术后清醒时间、拔管时间、术后呼吸次数和血氧饱和度均无显著差异。 2mg/kg曲马多组在给药后 1小时和 8小时VAS评分分别为 (1 33± 1 4 6 )分和 (1 5 4±1 6 5 )分 ,对照组分别为 (2 78± 1 87)分和 (2 6 1± 2 0 6 )分 (P <0 0 1,P <0 0 5 )。结果还显示 ,术毕给予 2mg/kg曲马多可明显减少术后PCA的吗啡用量及补救吗啡用量。 结论　术中使用 2mg/kg负荷剂量的曲马多可有效改善术后吗啡PCA的镇痛效果 ,并可减少PCA吗啡和补救吗啡用量。同时 ,曲马多的使用对术毕的清醒时间和呼吸恢复没有明显影响     

Ultra-fast-track anesthesia in off-pump coronary artery bypass grafting: a prospective audit comparing opioid-based anesthesia vs thoracic epiduralbased anesthesia

PURPOSE: To examine the feasibility of immediate extubation after off-pump coronary artery bypass grafting (OPCAB) using opioid based analgesia or high thoracic epidural analgesia (TEA) and compare postoperative analgesia with continuous TEA vs patient-controlled analgesia (PCA). METHODS: One hundred consecutive patients undergoing OPCAB were included in this prospective audit. After induction of anesthesia using fentanyl 2 to 5 microg.kg(-1), propofol 1 to 2 mg.kg(-1) and endotracheal intubation facilitated by rocuronium, anesthesia was maintained using sevoflurane titrated according to bispectral index monitoring. Perioperative analgesia was provided by TEA (n = 63) at the T3/T4 interspace or T4/T5 interspace using bupivacaine 0.125% 8 to 14 mL.hr(-1) and repetitive boluses of bupivacaine 0.25% during surgery. In patients who were fully anticoagulated or refused TEA, perioperative analgesia was achieved by i.v. fentanyl boluses (up to 15 microg.kg(-1)) and remifentanil 0.1 to 0.2 microg.kg(-1).min(-1), followed by morphine PCA after surgery (n = 37). Maintenance of body temperature was achieved by a heated operating room and forced-air warming blankets. RESULTS: Ninety-five patients were extubated within 25 min after surgery (PCA, n = 33; TEA, n = 62). Five patients were not extubated immediately because their core temperature was lower than 35 degrees C. One patient was re-intubated because of agitation (TEA group); one was re-intubated because of severe pain and morphine-induced respiratory depression (PCA group). Pain scores were low after surgery, with pain scores in the TEA group being significantly lower immediately, at six hours, 24 hr and 48 hr after surgery (P < 0.05). CONCLUSION: Immediate extubation is possible after OPCAB using either opioid-based analgesia or TEA. TEA provides significantly lower pain scores after surgery in comparison to morphine PCA.     

Posterior perineal block with ropivacaine 0.75% for pain control during and after hemorrhoidectomy

BACKGROUND AND OBJECTIVES: As perioperative pain management is a difficult challenge during hemorrhoidectomy, we tested the hypothesis that posterior perineal block (PPB) with local anesthetics alone is able to provide adequate pain control during and after surgery. METHODS: In a prospective, blinded, randomized study, we studied analgesic conditions and side effects of PPB in American Society of Anesthesiologists (ASA) I-II patients undergoing hemorrhoidectomy. Patients received general anesthesia (GA) either with PPB (0.75% ropivacaine, 40 mL (PPB group) or without PPB (control group). All patients received intravenous morphine patient-controlled analgesia (PCA) for postoperative pain control (morphine, 1.5 mg-boluses, 8-minute lockout interval). Intra- and postoperative opioids consumption was recorded, and pain assessments were performed at 1, 2, 4, 8, 12, and 24 hours using a visual analog scale (VAS). RESULTS: VAS scores were significantly lower during the first 8 postoperative hours in the PPB group as compared with the control group (P <.001). The PPB group required significantly less opioids during anesthesia (P <.001) and during the first postoperative day (P <.001) as compared with the control group. Time to first defecation and duration of hospitalization were identical in both groups. CONCLUSIONS: The present study shows that PPB with 40 mL 0.75% ropivacaine (300 mg) was a simple, effective, and safe method to provide better postoperative analgesia than PCA alone following surgical hemorrhoidectomy. In addition, PPB was shown to significantly reduce opioid consumption intraoperatively and during the first postoperative day.     

Preoperative emotional states in patients with breast cancer and postoperative pain

BACKGROUND: The present study examined the relationship between psychological variables, including anxiety, depression, and patient-controlled analgesia (PCA) use in patients who underwent radical mastectomy. METHODS: Ninety-nine ASA I-II women with breast cancer between 18 and 60 years scheduled for modified radical mastectomy completed the state scale of the state-trait anxiety inventory and the Beck depression inventory before the day of surgery. Standard general anesthesia, surgery, and IV-PCA therapy was conducted. Postoperative ratings of pain intensity, opioid consumption and satisfaction with PCA were recorded for the first 24 h on the ward. The degree of pain intensity was evaluated by a visual analog scale (VAS, 1-10). Satisfaction with pain control was reported using an five-point scale from 1 (very dissatisfied) to 5 (very satisfied). RESULTS: The pain intensity, total analgesic consumption and dose/demand ratio were significantly related to preoperative anxiety and depression (P<0.05). Degree of dissatisfaction with PCA was significantly correlated with preoperative anxiety and depression (P<0.01). CONCLUSION: Patients with higher anxiety and depression levels had higher postoperative pain and analgesic requirements in this study.     

Patient controllediv analgesia is an acceptable pain management strategy in morbidly obese patients undergoing gastric bypass surgery. A retrospective comparison with epidural analgesia

PURPOSE: To examine the hypothesis that pain treatment with patient controlled analgesia (PCA) using iv morphine is a suitable and safe alternative to epidural analgesia in morbidly obese patients undergoing gastric bypass surgery. We retrospectively compared the postoperative periods in all patients undergoing this procedure in our institution between November 1999 and November 2001. METHODS: According to their perioperative pain treatment, patients were assigned to a PCA group (with iv morphine) or an epidural analgesia group, in which patients received either intermittent doses of morphine or continuous infusions of bupivacaine/fentanyl. Study endpoints included quality of pain control, incidence of cardiovascular and respiratory complications, analgesia related side effects, time to ambulation and first flatus, length of hospital stay, and wound infections. RESULTS: Data from 86 patients were analyzed with 40 patients in the PCA group and 46 patients in the epidural group. Groups were similar with respect to age, body mass index, and gender. The type of analgesia did not affect the quality of pain control at rest, the frequency of nausea and pruritus, the time to ambulation and return of gastrointestinal function, and the length of hospital stay. Patients receiving epidural analgesia had a greater risk of wound infection than subjects with PCA (epidural group: 39%, PCA group: 15%, P = 0.01). CONCLUSION: We conclude that in grossly obese patients undergoing gastric bypass surgery PCA with iv morphine is an acceptable strategy for pain management and may confer some advantages when compared to epidural analgesia.     

Intravenous acetaminophen reduced the use of opioids compared with oral administration after coronary artery bypass grafting

OBJECTIVE: The purpose of this study was to evaluate if intravenous acetaminophen compared to oral administration reduced the consumption of opioids and their side effects without an increase in pain during the stay in the intensive care unit (ICU). DESIGN: Prospective, randomized study. SETTING: An ICU in a university hospital. PARTICIPANTS: Eighty patients with written informed consent undergoing coronary artery bypass grafting with cardiopulmonary bypass. Anesthesia was based on propofol and fentanyl combined with sevoflurane. INTERVENTIONS: Patients were randomized to 2 groups: acetaminophen, 1 g every sixth hour during the postoperative period, either as tablets or intravenously after extubation. MEASUREMENTS AND MAIN RESULTS: The amount of opioids administered during the study period was measured starting with acetaminophen administration during the stay in the ICU until 9 o'clock the following morning. Incidence of postoperative nausea and vomiting (PONV) was noted. Pain was evaluated with a visual analog scale (VAS) from 0 to 10. Three patients, 2 in the oral and 1 in the intravenous group, were excluded because of incomplete data. The intravenous group received less opioids than the orally treated group, 17.4 +/- 7.9 mg compared with 22.1 +/- 8.6 mg (p = 0.016). PONV incidence and VAS scores did not differ. During the first hours after extubation, 50 of 77 patients reported VAS scores >3 with no difference between groups. CONCLUSIONS: Intravenous acetaminophen had a limited opioid-sparing effect when compared with oral administration after coronary artery bypass graft surgery. The opioid-sparing effect was not accompanied by any reduction in the incidence of PONV. The clinical significance of the opioid-sparing effect could therefore be questioned.     

Epidural anesthesia during upper abdominal surgery provides better postoperative analgesia

Since repeated noxious stimuli may sensitize neuropathic pain receptors of the spinal cord, we tested the hypothesis that the appropriate blockade of surgical stimuli with epidural anesthesia during upper abdominal surgery would be beneficial for postoperative analgesia. Thirty-six adult patients undergoing either elective gastrectomy or open cholecystectomy were randomly allocated to receive either inhalational general anesthesia alone (group G) or epidural anesthesia along with light general anesthesia (group E) throughout the surgery. Postoperative pain management consisted of patient-controlled analgesia (PCA) with bupivacaine accompanied by the continuous infusion of buprenorphine. To assess postoperative pain, a visual analogue scale (VAS) was employed at 2, 24, and 48 h postoperatively. While there was no significant difference in the bupivacaine dose, more patients undergoing gastrectomy in group G required supplemental analgesics than those in group E, and the VAS scores in group E demonstrated significantly better postoperative analgesia compared to group G after both types of surgery. Thus, an appropriate epidural blockade during upper abdominal surgery likely provides better postoperative pain relief.     

The use of pre-operative intrathecal morphine for analgesia following coronary artery bypass surgery

With the emergence of rapid extubation protocols following cardiac surgery, providing adequate analgesia in the early postoperative period is important. This prospective randomised double-blind study investigated the benefits of pre-operative intrathecal administration of low dose morphine in patients undergoing coronary artery bypass graft surgery. Postoperative analgesia, pulmonary function, stress response and postoperative recovery profile were assessed. Thirty patients were allocated into two groups, receiving either 500 mug of morphine intrathecally prior to anaesthesia and intravenous patient-controlled analgesia with morphine postoperatively following tracheal extubation, or only postoperative intravenous patient-controlled analgesia. In the intrathecal group, the total consumption of intravenous morphine following surgery was significantly reduced by 40% and patients reported lower pain scores at rest, during the first 24 h following extubation. Peak expiratory flow rate was greater and postoperative catecholamine release was significantly lower. Patients in the control group had a higher incidence of reduced respiratory rate following extubation.     

Significance of patient-controlled analgesia in combination with continuous epidural block for patients who underwent posterior lumbar surgery

The purpose of the study was to evaluate the efficiency of patient-controlled analgesia (PCA) combined with continuous epidural block in patients who underwent lumbar spine surgery. In group 1 (postoperative PCA group), 23 patients were administered postoperative continuous epidural block in combination with analgesics, which was self-regulated by the patient using a device. In contrast, the 22 patients in group 2 (control group) received suppositories or intramuscular injections of analgesics on request. The following factors were compared between the two groups: pain relief according to the visual analog scale for pain assessment, the frequency of administration of analgesics, and side effects of the postoperative analgesia. The patients in group 1 had more satisfactory relief of pain according to the visual analog scale for pain assessment and needed suppositories and intramuscular injection of analgesics less frequently on the 1st, 2nd, and 3rd postoperative day. The time spent by nurses on pain management in group 1 was less than that in group 2. No patient had any serious complications in either group. In conclusion, the present patient-controlled method combined with postoperative continuous epidural block could decrease the intensity of postoperative pain and the amount of time spent by nurses on the administration of postoperative analgesics after lumbar spine surgery. Received: 17 July 1997 Revised: 30 September 1997 Accepted: 14 October 1997     

Intrathecal morphine and clonidine for coronary artery bypass grafting

Background. After cardiac surgery adequate postoperative analgesiais necessary. We assessed analgesia using intrathecal morphineand clonidine. Methods. In a double-blind randomized study, 45 patients havingcoronary artery bypass graft surgery were allocated randomlyto receive i.v. patient-controlled analgesia (PCA) morphine(bolus, 1 mg; lock-out interval, 7 min) (control group), eitheralone or combined with intrathecal morphine 4 µg kg^–1or with both intrathecal morphine 4 µg kg^–1and clonidine 1 µg kg^–1. Intrathecal injectionswere performed before the induction of general anaesthesia.Pain was measured after surgery using a visual analogue scale(VAS). We recorded i.v. PCA morphine consumption during the24 h after operation. Results. Morphine dosage [median (25th–75th percentiles)]was less in the first 24 h in the patients who were given intrathecalmorphine + clonidine [7 (0–37) mg] than in other patients[40.5 (15–61.5) mg in the intrathecal morphine group and37 (30.5–51) mg in the i.v. morphine group]. VAS scoreswere lower after intrathecal morphine + clonidine compared withthe control group. Time to extubation was less after intrathecalmorphine + clonidine compared with the i.v. morphine group [225(195–330) vs 330 (300–360) min, P<0.05]. Conclusion. Intrathecal morphine and clonidine provide effectiveanalgesia after coronary artery bypass graft surgery and allowearlier extubation. Br J Anaesth 2003; 90: 300–3     

Lack of pre-emptive analgesic effect of (R)-ketamine in laparoscopic cholecystectomy

AIM: This study evaluated the pre-emptive analgesic effect of intravenous (i.v.) (R)-ketamine in laparoscopic cholecystectomy. (R)-ketamine was used due to the lower incidence of side-effects. METHODS: Sixty patients who underwent surgery under general anesthesia were randomly allocated to 3 groups and studied in a double-blind manner. Two i.v. injections were administered: one after induction of anesthesia, approximately 3 min before surgery, and one after surgery. The placebo group (PLA, n = 20) received saline in both injections. The preoperative group (PRE, n = 20) received (R)-ketamine 1 mg/kg and then saline. The postoperative group (POST, n = 20) received saline and then (R)-ketamine 1 mg/kg. Postoperatively, the patients used a patient-controlled analgesia (PCA) pump. Pain was evaluated with a visual analog scale (VAS) at 30 min and every hour for 4 h and with a verbal rating scale (VRS) at 24 h and after 7 days. RESULTS: There were no occurrence of side-effects from (R)-ketamine. VAS and VRS at 1, 2, 3, and 4 h postoperatively showed no statistical differences. In the POST group, extubation was delayed and pain score (VAS) at 30 min postoperatively was significantly lower (P < 0.05) than the two other groups. There were no statistical differences in meperidine consumption during the first 4 h postoperatively and no differences in consumption of analgesics at 24 h and 7 days. CONCLUSION: In this study a 1 mg/kg dose of (R)-ketamine given at the end of surgery exerted a short-lasting hypnotic and analgesic effect. The same dose given preoperatively did not show postoperative analgesic effect or pre-emptive effect.     

Diversity of Opioid Requirements for Postoperative Pain Control Following Oral Surgery—Is It Affected by Polymorphism of the μ-Opioid Receptor?

We experience individual differences in pain and sensitivity to analgesics clinically. Genetic factors are known to influence individual difference. Polymorphisms in the human OPRM1 gene, which encodes the μ-opioid receptors, may be associated with the clinical effects of opioid analgesics. The purpose of this study was to determine whether any of the 5 common single-nucleotide polymorphisms (SNPs) of the OPRM1 gene could affect the antinociceptive effect of fentanyl. Fentanyl was less effective in subjects with the G allele of the OPRM1 A118G SNP than in those with the A allele, and subjects with the G allele required more fentanyl for adequate postoperative pain control than those with the A allele. In the future, identifying SNPs might give us information to modulate the analgesic dosage of opioid individually for better pain control. Factors underlying individual differences in sensitivity to pain other than genetic factors may include environmental and psychological factors. We therefore examined the effects of preoperative anxiety on the analgesic efficacy of fentanyl in patients undergoing sagittal split mandibular osteotomy (SSMO). From among the patients enrolled in the study, 60 patients (male/female: 18/42, age: 24.6 ± 6.7 years) who gave informed consent were examined for correlations between preoperative trait/state anxiety, as measured by the state-trait anxiety inventory (STAI) on the day before surgery, and postoperative consumption of patient-controlled analgesia (PCA) fentanyl and visual analog scale (VAS) assessment by patients. Levels of trait and state anxieties measured by the STAI were correlated with neither the consumption of PCA fentanyl nor postoperative VAS assessment. These findings suggest that psychological factors are unlikely to affect postoperative pain or the use of analgesics.