Dexmedetomidine in combination with morphine PCA provides superior analgesia for shockwave lithotripsy

PURPOSE: To compare the analgesic effects of dexmedetomidine/morphine with those of tramadol/midazolam in patients undergoing extracorporeal shockwave lithotripsy (ESWL) for urinary calculi. METHODS: Sixty patients were randomized to receive either dexmedetomidine 1 micro g*kg(-1) iv followed by 0.5 micro g*kg(-1)*hr(-1) infusion together with morphine patient-controlled analgesia [(PCA); 2 mg bolus, five minutes lockout, 2 mg*hr(-1) infusion; (Group DEX)], or tramadol 1.5 mg*kg(-1) pre-mixed with midazolam 30 micro g*kg(-1) iv followed by tramadol PCA [20 mg bolus, five minute lockout, 20 mg*hr(-1) infusion; (Group TRA)]. Pain was assessed at baseline and every 15 min thereafter. Patients' and urologist's satisfaction with analgesia and sedation were determined on a seven-point scale ranging from 1 (extremely dissatisfied) to 7 (extremely satisfied). Patient's discharge time was also documented. RESULTS: Visual analogue scale scores over time were consistently lower in Group DEX compared with Group TRA (P = 0.001). Patients' satisfaction with analgesia (5 +/- 1 vs 4 +/- 2, P = 0.012) and with sedation (6 +/- 1 vs 5 +/- 1, P = 0.020), and urologist's satisfaction (6 +/- 1 vs 4 +/- 2, P = 0.001) were all higher amongst Group DEX patients compared with Group TRA. There was no difference between discharge times of patients in Group DEX compared with those in Group TRA [85 (60,115) min vs 65 (40,95) min, P = 0.069]. CONCLUSION: Dexmedetomidine in combination with morphine PCA provided better analgesia for ESWL and was associated with higher patients' and urologist's satisfaction when compared with a tramadol/midazolam PCA combination.     

Intraoperative remifentanil infusion does not increase postoperative opioid consumption compared with 70% nitrous oxide

BACKGROUND: Remifentanil is commonly used to replace nitrous oxide in general anesthesia to avoid the side effects of the latter. However, there are reports that intraoperative remifentanil infusion can lead to acute opioid tolerance. In this study, the authors tried to determine the dose of remifentanil comparable in efficacy to 70% nitrous oxide and to evaluate its effect on postoperative pain and morphine consumption after colorectal surgery using isoflurane anesthesia. METHODS: Sixty adult patients undergoing open colorectal surgery were randomly assigned to receive either remifentanil or 70% nitrous oxide along with isoflurane anesthesia. After morphine analgesia titration in the postanesthesia care unit, patient-controlled analgesia was commenced. Morphine consumption and pain were scored at rest and during cough or movement for 24 h. RESULTS: The mean remifentanil infusion rate was 0.17 mug . kg . min. The median visual analog pain score on arrival in the postanesthesia care unit was 1 (0-10) in the nitrous oxide group and 3 (0-9) in the remifentanil group (P < 0.05). Otherwise, there was no difference in pain scores at 5, 10, and 15 min and no difference in the total morphine consumption during the stay in the postanesthesia care unit. The two groups had similar total morphine consumption in the first 24 h and pain scores at rest and during movement. The incidence of postoperative nausea and vomiting was 10% in both groups. There was no difference in the sedation scores. CONCLUSION: The substitution of 70% nitrous oxide with remifentanil at a mean infusion rate of 0.17 mug . kg . minute for colorectal surgery did not affect postoperative opioid consumption.     

The effect of pre-anaesthetic administration of intravenous dexmedetomidine on postoperative pain in patients receiving patient-controlled morphine

BACKGROUND AND OBJECTIVE: This prospective, randomized, double-blind, controlled study was designed to test the effect of pre-anaesthetic administration of dexmedetomidine, given as a single intravenous (i.v.) dose, on postoperative pain scores and morphine consumption in patients receiving patient-controlled morphine after abdominal surgery. METHODS: Sixty patients were randomly allocated to receive dexmedetomidine (1 microg kg(-1)) or saline 10 min before induction of anaesthesia. Twenty minutes before the end of surgery, all patients received a standardized (0.1 mg kg(-1)) loading dose of morphine. They were then allowed to use a patient-controlled analgesia (PCA) device giving bolus doses of morphine (0.02 mg kg(-1)). Pain, discomfort and sedation scores; cumulative morphine consumption; time to extubation; time to recovery; and any side-effects were recorded after recovery and at 1, 2, 6, 12 and 24 h after the start of PCA. RESULTS: The mean time to extubation at the end of anaesthesia and recovery time were similar in both groups. There were no significant differences between groups with regard to mean pain, discomfort, sedation and nausea scores. Cumulative morphine consumption was significantly lower in the dexmedetomidine group at 6, 12 and 24 h (P < 0.05). The incidence of side-effects did not differ between the groups. CONCLUSIONS: A single i.v. dose of dexmedetomidine (1 microg kg(-1)) given 10 min before induction of anaesthesia significantly reduced postoperative morphine consumption at identical pain scores compared to control, but had no effect on postoperative recovery time.     

Fentanyl or dexmedetomidine combined with desflurane for bariatric surgery

STUDY OBJECTIVE: Because fentanyl has ventilatory depressing effects, alternative methods for analgesia may be beneficial for management of bariatric surgery. We evaluated whether dexmedetomidine infusion could replace fentanyl for facilitation of open gastric bypass surgery. DESIGN: Randomized, single blinded, open label. SETTING: University teaching hospital. PATIENTS: Twenty bariatric patients with an average body mass index of 54 to 61 kg/m2 undergoing surgery for open gastric bypass. INTERVENTIONS: Patients were randomized to receive either fentanyl (0.5-microg/kg bolus, 0.5 microg.kg(-1).h(-1), n = 10) or dexmedetomidine (0.5-microg/kg bolus, 0.4 microg.kg(-1).h(-1), n = 10) for intraoperative analgesia. In both groups, end-tidal desflurane was adjusted to maintain the bispectral index at 45 to 50. MEASUREMENTS: In the operating room, blood pressure and heart rate were measured at 5-minute intervals. Bispectral index and end-tidal desflurane concentration were measured every hour. During recovery in the postanesthesia care unit, patient-evaluated pain scores and morphine use by patient-controlled analgesia pump were determined. MAIN RESULTS: During surgery, desflurane concentrations necessary to maintain the bispectral index at 45 to 50 were decreased, and blood pressure and heart rate were lower with in the dexmedetomidine compared with fentanyl group. In the postanesthesia care unit, pain scores and morphine use were decreased in the dexmedetomidine group. CONCLUSIONS: Dexmedetomidine, when used to substitute for fentanyl during gastric bypass surgery, attenuates blood pressure and provides postoperative analgesia.     

Intravenous acetaminophenvs oral ibuprofen in combination with morphine PCIA after Cesarean delivery

PURPOSE: To compare the effects of iv acetaminophen with those of oral ibuprofen with respect to postoperative pain control and morphine requirements in patients receiving morphine patient-controlled iv analgesia (PCIA) after Cesarean delivery. METHODS: Forty-five term patients scheduled for Cesarean delivery were randomized to receive acetaminophen 1 g iv every six hours plus oral placebo (group A) or ibuprofen 400 mg po every six hours plus iv placebo (group I); the first dose of study drug was given 30 min preoperatively. Postoperatively, all patients received PCIA for 48 hr using morphine bolus dose 2 mg iv, lockout interval ten minutes, and no basal infusion. Visual analogue scale (VAS; 0 to 10) at rest and morphine requirements were recorded every hour for four hours then every four hours for a total of 48 hr postoperatively. Patient satisfaction was recorded on a ten-point scale (from 1 to 10) 48 hr postoperatively. RESULTS: Visual analogue scale scores decreased similarly in both groups over time, however, there were no differences between groups at any time during the study period (estimated marginal means: 1.4 +/- SEM 0.2 vs 1.9 +/- SEM 0.2 for groups A and I, respectively, P = 0.124). Cumulative doses of postoperative morphine were 98 +/- 37 vs 93 +/- 33 mg for groups A and I, respectively (P = 0.628). Patient satisfaction with analgesia was high in both groups (9 +/- 1 vs 9 +/- 1, P = 0.93). CONCLUSION: Intravenous acetaminophen is a reasonable alternative to oral ibuprofen as an adjunct to morphine patient-controlled analgesia after Cesarean delivery.     

Postoperative pain management with intravenous patient-controlled morphine: comparison of the effect of adding magnesium or ketamine

BACKGROUND AND OBJECTIVE: This double-blind randomized study tested whether the addition of magnesium or ketamine to morphine for intravenous patient-controlled analgesia resulted in improved analgesic efficacy and lower pain scores compared with morphine patient-controlled analgesia alone after major abdominal surgery. METHOD: Ninety patients (3 x 30) were randomly allocated to receive either morphine 0.4 mg mL(-1) (Group M) by patient-controlled analgesia, morphine 0.4mg mL(-1) + MgSO4 30mg mL(-1) (Group MM) or morphine 0.4 mg mL(-1) + ketamine 1 mg mL(-1) (Group MK). Postoperative analgesia was started when the verbal rating scale was > or = 2. Patients were first given a standardized loading dose (0.05 mg kg(-1)) of the study solution. They were then allowed to use bolus doses of this solution (0.0125 mg kg(-1) every 20 min without time limit). Discomfort, sedation, pain scores, cumulative morphine consumption and adverse effects were recorded up to 24 h after the start of the patient-controlled analgesia. RESULTS: The level of discomfort, level of sedation and verbal rating scores decreased significantly with time in all groups (P < 0.05). Both verbal rating and discomfort scores were significantly lower in Groups MM and MK at 15, 30 and 60 min compared with Group M (P < 0.001). Cumulative morphine consumption after 12 and 24 h was significantly higher in Group M alone (median 26 and 49 mg, respectively) compared with Group MM (24.2 and 45.7 mg) and Group MK (24.4 and 46.5 mg). CONCLUSIONS: In the immediate postoperative period, the addition of magnesium or ketamine to morphine for intravenous patient-controlled analgesia led to a significantly lower consumption of morphine. However, these differences are unlikely to be of any clinical relevance.     

Small-dose ketamine infusion improves postoperative analgesia and rehabilitation after total knee arthroplasty

We designed this study to evaluate the effect of small-dose IV ketamine in combination with continuous femoral nerve block on postoperative pain and rehabilitation after total knee arthroplasty. Continuous femoral nerve block was started with 0.3 mL/kg of 0.75% ropivacaine before surgery and continued in the surgical ward for 48 h with 0.2% ropivacaine at a rate of 0.1 mL . kg(-1) . h(-1). Patients were randomly assigned to receive an initial bolus of 0.5 mg/kg ketamine followed by a continuous infusion of 3 mug . kg(-1) . min(-1) during surgery and 1.5 mug . kg(-1) . min(-1) for 48 h (ketamine group) or an equal volume of saline (control group). Additional postoperative analgesia was provided by patient-controlled IV morphine. Pain scores and morphine consumption were recorded over 48 h. The maximal degree of active knee flexion tolerated was recorded daily until hospital discharge. Follow-up was performed 6 wk and 3 mo after surgery. The ketamine group required significantly less morphine than the control group (45 +/- 20 mg versus 69 +/- 30 mg; P < 0.02). Patients in the ketamine group reached 90 degrees of active knee flexion more rapidly than those in the control group (at 7 [5-11] versus 12 [8-45] days, median [25%-75% interquartile range]; P < 0.03). Outcomes at 6 wk and 3 mo were similar in each group. These results confirm that ketamine is a useful analgesic adjuvant in perioperative multimodal analgesia with a positive impact on early knee mobilization. No patient in either group reported sedation, hallucinations, nightmares, or diplopia, and no differences were noted in the incidence of nausea and vomiting between the two groups.     

A background infusion of morphine does not enhance postoperative analgesia after cardiac surgery

PURPOSE: To compare the effects of patient-controlled analgesia (PCA), with or without a background infusion of morphine on postoperative pain relief and stress response after cardiac anesthesia. METHODS: With University Ethics approval, 35 consenting adults undergoing elective open-heart surgery were randomly assigned preoperatively in a double-blind fashion to receive either morphine PCA alone (Group I, n = 15) or morphine PCA plus a continuous basal infusion (Group II, n = 14) for 44 hr postoperatively. Pain scores with visual analogue scale (VAS) at rest, deep inspiration and with cough, sedation scores, stress hormone levels [cortisol, adrenocorticotropin (ACTH) and growth hormone (GH)] and morphine consumption were assessed, and serum morphine levels were measured at four, 20, 28 and 44 hr after surgery. Adverse effects including nausea, vomiting, constipation, urinary retention and pruritus were noted. Total blood, fluid requirements, drainage and urinary output were recorded. RESULTS: Postoperative morphine consumption at 44 hr was less in Group I (29.43 +/- 12.57 mg) than in Group II (50.14 +/- 16.44 mg), P = 0.0006. There was no significant difference between groups in VAS scores, GH levels, blood levels of morphine and adverse effects. While VAS scores, ACTH and GH levels decreased significantly in both groups, plasma cortisol levels increased significantly in Group I only at four hours. In Group II, ACTH and cortisol were higher at four and 44 hr respectively. CONCLUSION: PCA with morphine effectively controlled postoperative pain after cardiac surgery. The addition of a background infusion of morphine did not enhance analgesia and increased morphine consumption.     

Postoperative hypoxaemia: continuous extradural infusion of bupivacaine and morphine vs patient-controlled analgesia with intravenous morphine

We carried out a randomized prospective study in 60 patients who had undergone major abdominal surgery for cancer. For postoperative pain control, 30 patients received continuous extradural infusion of 0.125% bupivacaine 12.5 mg h-1 and morphine 0.25 mg h-1 (EXI group) and 30 received patient-controlled analgesia (PCA) with intravenous morphine (1 mg bolus, 5-min lock-out and maximum dose 20 mg 4h-1). Both groups had general anaesthesia. The two groups were compared for postoperative pain scores, satisfaction, sedation and oxygen saturation. Oxygen saturation was recorded continuously the night before surgery and for two consecutive postoperative nights. Episodes of moderate desaturation (90% > SpO2 85%) were more frequent in the EXI group than in the PCA group (P < 0.05). Pain scores were lower in the EXI group compared with the PCA group at rest and while coughing (P < 0.05). No significant difference was found for patient sedation and satisfaction.      

A randomised, controlled study of peri-operative low dose s(+)-ketamine in combination with postoperative patient-controlled s(+)-ketamine and morphine after radical prostatectomy

In a randomised, double-blind prospective study we compared the effects on postoperative pain and analgesic consumption of intra-operative s(+)-ketamine (100 microg.kg-1 bolus and a continuous infusion of 2 microg.kg-1.min-1) followed by postoperative patient-controlled analgesia with morphine (1 mg per bolus) plus s(+)-ketamine (0.5 mg per bolus), or intra-operative saline followed by postoperative patient-controlled analgesia morphine (1 mg per bolus) alone. A total of 28 male patients undergoing radical prostatectomy were studied. Morphine consumption, pain scores, pressure algometry and adverse effects were recorded for 48 h after surgery. Cumulative morphine consumption was significantly lower in the ketamine/morphine group (47.9 +/- 26.2 mg) than in the saline/morphine group (73.4 +/- 34.8 mg; p = 0.049). Pain scores at rest were significantly lower in the ketamine/morphine group across the 48-h study period (p = 0.01). No significant differences were found in pressure algometry measurements or the occurrence of adverse effects.     

Effect of combining naloxone and morphine for intravenous patient-controlled analgesia

BACKGROUND: An early study showed that a naloxone infusion decreased the incidence of morphine-related side effects from intravenous patient-controlled analgesia. The authors tested the hypothesis that a more convenient combination of morphine and naloxone via patient-controlled analgesia would decrease the incidence of side effects compared to morphine alone. METHODS: Patients scheduled for hysterectomy under general anaesthesia were enrolled in a double-blind, randomized, placebo-controlled trial. Patients received a standardized general anesthetic and postoperative patient-controlled analgesia. They were randomized to receive 60 mg patient-controlled analgesia morphine in 30 ml saline or 60 mg morphine in 30 ml saline with naloxone 0.8 mg. Parameters for patient-controlled analgesia were a 1-mg bolus of morphine with a 5-min lockout and no background infusion. Patient recall of nausea, vomiting, itching, and pain (at rest and with movement) were assessed at 6 and 24 h postoperatively by verbal rating score. Pain was also assessed by a 0- to 100-mm visual analog score, and sedation was assessed by an observer. The amount of morphine used and the requirements for symptomatic treatment were also recorded. RESULTS: Ninety-two patients completed the study, with no significant differences in outcomes between groups. At 24 h, the incidence of nausea was 84.8% in each group; the incidence of pruritus was 56.5% in the naloxone group and 58.7% in the placebo group. There were also no differences in symptomatic treatment requirements, pain scores, morphine use, or sedation between groups. The median dose of naloxone received equated to 0.38 microg x kg-1 x h-1 over 24 h. CONCLUSIONS: There was no benefit from administering naloxone combined with morphine via patient-controlled analgesia.     

Patient-controlled epidural analgesia with morphine or morphine plus ketamine for post-operative pain relief

Sixty patients were randomly assigned to two equal groups. Group I received epidural morphine 1 mg after surgery and used a patient-controlled analgesia device programmed to deliver morphine 0. 2 mg h-1, 0.2 mg per bolus. Group II received an epidural loading dose of morphine 1 mg plus ketamine 5 mg and used a patient-controlled analgesia device programmed to deliver morphine 0. 2 mg+ketamine 0.5 mg h-1, morphine 0.2 mg+ketamine 0.5 mg per bolus with a lockout time of 10 min. The mean morphine consumption was 8. 6+/-0.7 mg for group I and 6.2+/-0.2 mg for group II. Although group II utilized significantly less morphine (P < 0.05), pain relief was significantly better in group II than in group I (P < 0.05) in the first 3 h. Vomiting occurred more frequently in group I (26%) than in group II (13%). The frequency and severity of pruritus and level of sedation were similar in the two groups. These findings suggest that patient-controlled epidural analgesia with morphine plus ketamine may provide effective analgesia with a lesser dose of morphine and fewer subsequent side effects, compared with patient-controlled epidural analgesia with morphine alone after lower abdominal surgery.     

Effects of dexmedetomidine in morbidly obese patients undergoing laparoscopic gastric bypass

BACKGROUND: Obese patients may be sensitive to the respiratory depressant effect of opioid analgesics. Alternative methods for analgesia may be beneficial for management of bariatric surgery. We evaluated the effect of dexmedetomidine on anesthetic requirements during surgery, hemodynamic, recovery profile and morphine use in the postoperative period. METHODS: Eighty adult patients scheduled for elective laparoscopic Roux-en-Y gastric bypass surgery were randomly assigned to one of two study groups; Group D (40 patients) received dexmedetomidine (0.8-microg/kg bolus, 0,4 microg kg(-1) h) and Group P (40 patients) received normal saline (placebo) in the same volume and rate. Intraoperative and postoperative mean blood pressure and heart rate were recorded. The total amount of intraoperative fentanyl and propofol required to maintain anesthesia were measured. Recovery profile, pain score and total amount of morphine used via patient controlled analgesia (PCA) were assessed. RESULTS: During surgery, dexmedetomidine decreased the total amount of intraoperative fentanyl and propofol required for maintenance of anesthesia compared to placebo. Patients who received dexmedetomidine showed significant decrease of intraoperative and postoperative mean blood pressure, heart rate. In the postoperative period, dexmedetomidine decreased pain scores and PCA morphine use significantly and showed better recovery profile as compared to the placebo Group. There was no difference in the incidence of postoperative nausea and vomiting (PONV) between both groups. CONCLUSION: The intraoperative infusion of dexmedetomidine decreased the total amount of propofol and fentanyl required to maintain anesthesia, offered better control of intraoperative and postoperative hemodynamics, decreased postoperative pain level, decreased the total amount of morphine used and showed better recovery profile compared with placebo.     

Effect of Combining Naloxone and Morphine for Intravenous Patient-controlled Analgesia

Background: An early study showed that a naloxone infusion decreased the incidence of morphine-related side effects from intravenous patient-controlled analgesia. The authors tested the hypothesis that a more convenient combination of morphine and naloxone via patient-controlled analgesia would decrease the incidence of side effects compared to morphine alone.

Methods: Patients scheduled for hysterectomy under general anaesthesia were enrolled in a double-blind, randomized, placebo-controlled trial. Patients received a standardized general anesthetic and postoperative patient-controlled analgesia. They were randomized to receive 60 mg patient-controlled analgesia morphine in 30 ml saline or 60 mg morphine in 30 ml saline with naloxone 0.8 mg. Parameters for patient-controlled analgesia were a 1-mg bolus of morphine with a 5-min lockout and no background infusion. Patient recall of nausea, vomiting, itching, and pain (at rest and with movement) were assessed at 6 and 24 h postoperatively by verbal rating score. Pain was also assessed by a 0- to 100-mm visual analog score, and sedation was assessed by an observer. The amount of morphine used and the requirements for symptomatic treatment were also recorded.

Results: Ninety-two patients completed the study, with no significant differences in outcomes between groups. At 24 h, the incidence of nausea was 84.8% in each group; the incidence of pruritus was 56.5% in the naloxone group and 58.7% in the placebo group. There were also no differences in symptomatic treatment requirements, pain scores, morphine use, or sedation between groups. The median dose of naloxone received equated to 0.38 [mu]g [middle dot] kg-1 [middle dot] h-1 over 24 h.     

The posterior lumbar plexus (psoas compartment) block and the three-in-one femoral nerve block provide similar postoperative analgesia after total knee replacement

PURPOSE: To compare the efficacy of a continuous posterior lumbar plexus (PSOAS) block to a continuous three-in-one femoral nerve (FEM) block in patients undergoing primary total knee replacement (TKR). METHODS: Sixty patients were randomly allocated to receive iv patient-controlled morphine analgesia (PCA), PCA plus a continuous FEM block with 30 mL ropivacaine 0.5% and epinephrine 1:200,000 bolus followed by an infusion of ropivacaine 0.2% at 12 mL.hr(-1) for 48 hr, or PCA plus a continuous PSOAS block with the same bolus and infusion regimen as the FEM group. Postoperative morphine consumption, verbal analogue scale pain scores at rest and during physiotherapy, and evidence of sensory and motor blockades were noted. RESULTS: Both regional techniques significantly reduced 48 hr morphine consumption (FEM 37.3 +/- 34.7 mg, P = 0.0002; PSOAS 36.1 +/- 25.8 mg, P < 0.0001) compared to PCA (72.2 +/- 26.6 mg). Pain scores at rest, six and 24 hr after TKR were lower in the FEM and PSOAS groups compared to the PCA group (P < 0.0001). Although sensory and motor blockades of the obturator nerve were achieved more often in the PSOAS group than in the FEM group (P < 0.0001), morphine consumption and pain scores did not differ between the two groups. CONCLUSION: Both continuous PSOAS block and continuous three-in-one FEM block provided better analgesia than PCA but no differences were seen between the two regional techniques.     

Comparison of epidurally administered sufentanil, morphine, and sufentanil-morphine combination for postoperative analgesia

Postoperative analgesia provided by epidurally administered sufentanil and/or morphine was evaluated in 45 patients recovering from major gynecologic surgery. At the first complaint of pain in the Postanesthesia Care Unit, patients received a single epidural bolus of 30 micrograms sufentanil (group A), 5 mg morphine (group B), or 30 micrograms sufentanil plus 3 mg morphine (group C) in a randomized blinded fashion. Analgesic efficacy was assessed throughout the 24-h study period with 10-cm visual analog scales. The need for additional postoperative analgesia (patient-controlled analgesia, 1 mg of morphine every 6 min as necessary) and the incidence of adverse effects were also assessed. Patients receiving sufentanil (groups A and C) had significantly faster onset of analgesia than did patients given morphine alone (group B, P less than 0.05). Group B subjects experienced the longest duration of analgesia (B vs A and C, P less than 0.05) and required significantly less patient-controlled analgesia (morphine) than patients in group A (P less than 0.05). No patient developed clinically significant respiratory depression or excessive sedation, and there were no intergroup differences in incidence of pruritus or nausea (P value not significant). The data indicate that a mixture of sufentanil and morphine provides either a more rapid onset of epidural analgesia or reduced patient-controlled analgesia narcotic requirement than respective doses of each agent administered alone.     

Postoperative nausea and vomiting in children using patient-controlled analgesia: the effect of prophylactic intravenous dixyrazine

BACKGROUND: Although patient-controlled analgesia (PCA) with morphine provides a high degree of satisfactory postoperative analgesia in children, it is often associated with a high incidence of postoperative nausea and vomiting (PONV). Our aim in this study was to evaluate the prophylactic effect of dixyrazine, a phenothiazine with proven anti-emetic properties. METHODS: The incidence of nausea and vomiting was studied in 60 children using PCA after major surgery. The patients were randomised to receive either dixyrazine 0.25 mg kg-1 or placebo on the induction of anaesthesia in a double-blind, placebo-controlled design. The anaesthetic technique was standardised. The PCA pump was programmed to deliver bolus doses of morphine of 20 micrograms kg-1 with a continuous background infusion of 8-10 micrograms kg-1 h-1. Nausea, vomiting, sedation and pain scores were noted every 3 h for a period of 24 h. RESULTS: The morphine consumption of morphine was the same in both groups. During the stay in the recovery room the incidence of vomiting was 3% in the dixyrazine group compared to 30% in the placebo group (P < 0.05). On the ward, 57% versus 83% of the children vomited (P < 0.05). Rescue antiemetics were significantly lower, 30%, in the dixyrazine group compared to 60% in the placebo group (P < 0.05). Higher sedation scores were recorded for the dixyrazine group in the recovery room. No other adverse effects were found. CONCLUSION: A significant number of children using PCA with morphine after major surgery experience PONV. Although prophylactic dixyrazine reduces the incidence and severity of vomiting, the incidence still remains high.     

右美托咪定复合罗哌卡因连续腰丛神经阻滞对髋关节置换术后早期康复的影响

目的探讨右美托咪定复合罗哌卡因连续腰丛神经阻滞对髋关节置换术后早期康复的影响。方法选择择期行全髋关节置换术的老年患者60例,男35例,女25例,年龄65~84岁,ASAⅡ或Ⅲ级。随机分为两组,每组30例。术后均接受连续腰丛神经阻滞镇痛,背景剂量8ml/h,冲击剂量4ml/30min。D组配方为1μg/ml右美托咪定+0.1%罗哌卡因,C组配方为0.2%罗哌卡因。所有患者同时接吗啡静脉镇痛泵(1 mg/ml吗啡50 ml)作为爆发疼痛时的解救药,冲击剂量1ml/5min,无背景输注。观察吗啡用量、术后6、12、24和48h的静息及运动VAS疼痛评分、患肢肌力、髋关节最大屈曲和外展活动度。记录术后不良反应的发生情况。于术前1d、术后第1、7天采用匹兹堡睡眠指数(Pittsburgh sleep quality index,PSQI)评价睡眠质量。结果 D组吗啡用量明显少于C组(P0.05)。两组静息和运动VAS疼痛评分差异无统计学意义。术后6、12、24和48h,D组患肢肌力评分明显高于C组,髋关节最大外展活动度和最大屈曲度明显大于C组(P0.05)。与术前1d比较,术后第1天和第7天两组的PSQI评分明显增高,且D组明显低于C组(P0.05)。D组术后恶心呕吐、瘙痒、谵妄等不良反应发生率明显低于C组(P0.05)。结论相对于0.2%罗哌卡因,1μg/ml右美托咪定复合0.1%罗哌卡因连续腰丛神经阻滞可以为髋关节置换术后早期提供更好的镇痛,提高术后睡眠质量,有利于患者关节功能锻炼和术后早期康复。     

Anesthesia for a patient with morbid obesity using dexmedetomidine without narcotics

PURPOSE: To describe the anesthetic management of a patient with extreme obesity undergoing bariatric surgery whose intraoperative narcotic management was entirely substituted with dexmedetomidine. CLINICAL FEATURES: We describe a 433-kg morbidly obese patient with obstructive sleep apnea and pulmonary hypertension who underwent Roux-en-Y gastric bypass. Because of the concern that the use of narcotics might cause postoperative respiratory depression, we substituted their intraoperative use with a continuous infusion of dexmedetomidine (0.7 microg.kg(-1).hr(-1)). The anesthesia course was uneventful, and the intraoperative use of dexmedetomidine was associated with low anesthetic requirements (0.5 minimum alveolar concentration). After completion of the operation and after tracheal extubation, the dexmedetomidine infusion was continued uninterrupted throughout the end of the first postoperative day. The analgesic effects of dexmedetomidine extended narcotic-sparing effects into the postoperative period; the patient had lower narcotic requirements during the first postoperative day [48 mg of morphine by patient-controlled analgesia (PCA)] while still receiving dexmedetomidine, compared to the second postoperative day (morphine 148 mg by PCA) with similar pain scores. CONCLUSION: Dexmedetomidine may be a useful anesthetic adjunct for patients who are susceptible to narcotic-induced respiratory depression. In this morbidly obese patient the narcotic-sparing effects of dexmedetomidine were evident both intraoperatively and postoperatively.     

Role of magnesium sulfate in postoperative pain management for patients undergoing thoracotomy

OBJECTIVE: The purpose of this study was to investigate the effect of magnesium sulfate on pain management for post-thoracotomy patients. DESIGN: A prospective, randomized, controlled clinical study. SETTING: University hospital. PARTICIPANTS: Twenty-four patients undergoing thoracotomy. INTERVENTIONS: After thoracotomy operations, patients were assigned to 2 groups. The control group received intravenous morphine (0.5 mg/h infusion, 0.3 mg patient-controlled anesthesia dose, 15-minute lockout time) via patient-controlled analgesia, and the magnesium group received magnesium sulfate (30-mg/kg bolus, 10 mg/kg/h infusion for 48 hours) plus the same patient-controlled analgesia protocol. MEASUREMENTS AND MAIN RESULTS: Visual analog scale for pain score, sedation score, mean arterial pressure, heart rate, and valid and invalid analgesic demand were recorded. Serum magnesium levels were determined at postanesthesia care unit admission, at 24 hours, and at 48 hours. Side effects were also recorded. There were no significant differences between groups with respect to demographics, sedation score, and pain score. Cumulative mean morphine consumption was found to be higher in the control group compared with the magnesium group at 4, 8, and 48 hours (5.6 +/- 1 mg v 3.2 +/- 0.6 mg [p < 0.0001], 10.2 +/- 1.8 mg v 7.2 +/- 1.6 mg [p = 0.0003), and 40.2 +/- 4.5 mg v 34.8 +/- 6.3 mg [p = 0.02], respectively). CONCLUSION: Postoperative use of magnesium sulfate reduced opioid consumption for pain after thoracotomy operations.