Ketamine does not decrease postoperative pain after remifentanil-based anaesthesia for tonsillectomy in adults

BACKGROUND: There are conflicting results concerning the pre-emptive effect of ketamine on central sensitization following surgery. The aim of this prospective, randomized, double-blind, placebo-controlled study was to assess the effect of the N-methyl-D-aspartate receptor antagonist ketamine on postoperative morphine consumption and pain score after remifentanil-based anaesthesia in adult patients scheduled for tonsillectomy. METHODS: We studied 40 adult patients undergoing elective tonsillectomy. Total intravenous anaesthesia was induced and maintained with remifentanil (0.125-1.0 microg kg(-1) min(-1)) and propofol target-controlled infusion. Patients in group K received a bolus dose of ketamine 0.5 mg kg(-1) immediately after anaesthetic induction, followed by a continuous infusion of 2 microg kg(-1) min(-1). Saline was administered in the same sequence in group S. Propofol, remifentanil, and the study drug infusions were discontinued at the end of surgery. RESULTS: Intraoperative remifentanil consumption (0.57 +/- 0.18 in group K vs. 0.55 +/- 0.14 microg kg(-1) min(-1) in group S), morphine requirement in the PACU (11 +/- 3 in group K vs. 9 +/- 4 mg in group S) and in the ward (22 +/- 11 in group K vs. 25 +/- 14 mg in group S), median time to first analgesia in the ward (338 +/- 126 in group K vs. 328 +/- 144 min in group S), and VAS pain scores were comparable in both groups. CONCLUSION: Small-dose of ketamine does not seem to be a useful adjunct to remifentanil-based anaesthesia during short, painful surgical procedures.     

Remifentanil with morphine transitional analgesia shortens neurological recovery compared to fentanyl for supratentorial craniotomy

PURPOSE: To compare the recovery profiles, efficacy and safety of remifentanil and morphine for transitional analgesia with fentanyl in patients undergoing elective craniotomy for supratentorial mass lesions. METHODS: Ninety-one patients were enrolled in this prospective, randomized, multicentre study. Anesthesia was induced with thiopental and remifentanil (1.0 micro g x kg(-1) bolus and a 1 micro g x kg(-1) x min(-1) infusion) or fentanyl (1 micro g x kg(-1) bolus and a 1.0 micro g x kg(-1) x min(-1) infusion). The opioid infusion continued until the level of anesthesia was deemed appropriate for intubation. Anesthesia was maintained with N(2)O/O(2), isoflurane 0.5 MAC and remifentanil 0.2 micro g x kg(-1) x min(-1) or fentanyl 0.04 micro g x kg(-1) x min(-1). At bone flap replacement, either morphine 0.08 mg x kg(-1) (remifentanil group) or saline (fentanyl group) was given. RESULTS: Systolic blood pressure was greater in those receiving fentanyl during induction (145.6 +/-17.5 mmHg vs 128.8 +/-18.3 mmHg; P = 0.006) and intubation (126.9 +/-17.1 vs 110.9 +/-16.5 mmHg; P < 0.001). Median time to tracheal extubation was similar but less variable in the remifentanil group (remifentanil = 8 min: range = 2-44 min; fentanyl = 8 min: range = 1-732 min). The fentanyl patients required a longer time to achieve the first normal neurological score (fentanyl = 38.0 min; remifentanil = 26.0 min; P = 0.035). Both the anesthesiologists and the recovery room nurses rated remifentanil better with respect to level of consciousness. Analgesics were required earlier in patients receiving remifentanil; median time 0.5 vs 1.08 hr, P < 0.001. CONCLUSIONS: Remifentanil is a suitable alternative to fentanyl in supratentorial craniotomy. Time to preoperative neurological recovery is faster and morphine provides some transitional analgesia without compromising the quality of recovery.     

Preoperative rectal diclofenac versus paracetamol for tonsillectomy: effects on pain and blood loss

BACKGROUND: Diclofenac is widely used for postoperative analgesia but the perioperative safety of this drug is controversial because of its effect on platelet aggregation, which might increase blood loss. In a prospective investigator-blinded study the effects of diclofenac and paracetamol on pain and blood loss were compared in patients undergoing tonsillectomy. METHOD: Ninety patients were randomised to receive rectal diclofenac 0.65-1.0 mg x kg(-1) or paracetamol 13-20 mg x kg(-1) preoperatively. Ten patients were excluded after randomisation. Pain was evaluated postoperatively by means of the visual analogue scale and by recording the use of pethidine for rescue analgesia. Perioperative blood loss was estimated from measured intraoperative blood loss; use of drugs to achieve haemostasis, and the incidence of reoperations. RESULTS: Anaesthetic or surgical managements did not differ between the groups, but a significantly longer period of surgery was found in the diclofenac group, 32+/-16 vs. 25+/-11 min (P = 0.024). Pain scores or pethidine consumption were not significantly different between the groups. Intraoperative blood loss was significantly larger in the diclofenac group, 1.9 (1.1-3.1) vs. 1.1 (0.7-2.0) ml x kg(-1) (P = 0.007). CONCLUSION: Preoperative rectal diclofenac offers no advantage over paracetamol with respect to postoperative analgesia in tonsillectomy patients but increases intraoperative blood loss.     

Ketamine reduces swallowing-evoked pain after paediatric tonsillectomy

BACKGROUND: Ketamine efficacy as an analgesic adjuvant has been studied in several clinical settings with conflicting results. The aim of this study was to investigate the effect of ketamine on spontaneous and swallowing-evoked pain after tonsillectomy. METHODS: Fifty children were randomized to receive premedication with either ketamine 0.1 mg kg(-1) i.m. or placebo given 20 min before induction of a standard general anaesthesia. All children received rectal diclofenac 2 mg kg(-1) and fentanyl 1 micro g kg(-1) i.v. before surgery. RESULTS: The ketamine group showed significantly lower pain scores both at rest and on swallowing, with less total paracetamol consumption (P < 0.05) during the 24 h after surgery. Significantly more patients required postoperative morphine titration in the control group (P < 0.05). The time to the first oral intake, and duration of i.v. hydration, were significantly shorter and the quality of oral intake was significantly better in the ketamine group (P < 0.05). There were no differences in the incidence of vomiting or dreaming between the groups. CONCLUSION: Premedication with a small dose of ketamine reduces swallowing-evoked pain after tonsillectomy in children who received an analgesic regimen combining an opioid and a NSAID.     

Remifentanil induces consistent and sustained controlled hypotension in children during middle ear surgery

PURPOSE: To determine in children whether remifentanil combined with sevoflurane, could induce controlled hypotension, reduce middle ear blood flow (MEBF) measured by laser-Doppler, and provide a satisfactory operative field. METHODS: Forty children undergoing middle ear surgery and anesthetized with sevoflurane were randomly assigned to receive either 1 micro g x kg(-1) remifentanil iv followed by a continuous infusion of 0.2 to 0.5 micro g x kg(-1) x min(-1) or 0.25 micro g x kg(-1) x min(-1) nitroprusside iv and alfentanil iv (n = 20 in each group). RESULTS: Controlled hypotension was achieved at the target mean arterial pressure (MAP) of 50 mmHg (P < 0.01) within 121 +/- 21 and 62 +/- 9 sec for remifentanil and nitroprusside respectively. MEBF decreased by 22 +/- 4 and 20 +/- 6% and preceded the decrease in MAP within 20 +/- 7 and 10 +/- 3 sec for remifentanil and nitroprusside respectively. Remifentanil, and nitroprusside decreased MEBF autoregulation (0.41 +/- 0.2 and 0.37 +/- 0.3 respectively). Controlled hypotension was sustained in both groups throughout surgery, and the surgical field rating was good. Nitroprusside increased PaCO(2) slightly, and there were no postoperative circulatory, neurological or metabolic complications in any of the groups. CONCLUSION: Remifentanil combined with sevoflurane in children enabled controlled hypotension, reduced MEBF and provided good surgical conditions for middle ear surgery with no need for additional use of a specific hypotensive agent.     

Postoperative pain management in patients undergoing major surgery after remifentanilvs fentanyl anesthesia

PURPOSE: To determine if morphine sulphate was an effective transition analgesic in patients receiving a remifentanil-based anesthetic regimen. METHODS: Open-label remifentanil or fentanyl was administered to 210 randomized patients undergoing inpatient surgery. Isoflurane and nitrous oxide was administered to all patients. Thirty minutes before the end of surgery, patients receiving remifentanil were randomized to receive morphine 0.15 mg x kg(-1) (R/M15 group) or 0.20 mg x kg(-1) (R/M20 group). Following extubation and prior to patient-controlled analgesia (PCA) initiation, 2 mg boluses of morphine were administered for moderate/severe pain. Efficacy endpoints were total morphine used in the post anesthesia care unit (PACU) and 24 and 48 hr postoperatively; postoperative pain; time to first morphine bolus; time to first PCA administration; and time to recovery endpoints. RESULTS: Mean total morphine used in PACU was not different among groups (15.5 mg, 16.5 mg and 13.3 mg in R/M 15, R/M20 and F groups, respectively). Mean total 24 hr morphine use (58.1 mg, 56.93 mg and 53.6 mg in R/M15, R/M20 and F groups) and mean total morphine used at 48 hr were not different (69.8 mg, 64.7 mg and 62.1 mg in R/M15, R/M20 and F/I groups). Groups were similar with respect to pain severity ratings at all postoperative times. Patients in the fentanyl arm experienced faster times to some recovery endpoints than patients receiving either remifentanil regimen. CONCLUSION: Morphine sulphate regimens of 0.15 or 0.20 mg x kg(-1) administered 30 min before the end of surgery are equally effective transition regimens for inpatient procedures.     

The combined effect of ketamine and remifentanil infusions as total intravenous anesthesia for scoliosis surgery in children

BACKGROUND: This study was designed to assess the effect of combination of ketamine and remifentanil infusions as total intravenous anesthesia (TIVA) during scoliosis surgery in children. METHODS: Thirty two children, 8-14 yr of age, scheduled for posterior spinal fusion, were randomly allocated into two equal groups to receive either remifentanil infusion in a dose of 0.2 microg/kg/minutes or same dose of remifentanil infusion combined with ketamine infusion in a dose of 1 microg/kg/minutes after induction of general anesthesia. During surgery, hemodynamics, surgical bleeding, and electrophysiology monitors were recorded. After completion of surgery, recovery score, recovery time and rescue analgesia were assessed in post-anesthesia care unit (PACU) for 24 hours. RESULTS: The two groups were similar for age, weight, duration of surgery, and time to extubation. Intraoperative heart rate and arterial blood pressure were significantly decreased in remifentanil group when compated to remifentanil-ketamine group. The surgical bleeding and electrophysiological monitoring were not significantly affected by remifentanil-ketamine combination in second group. Recovery score and recovery time were not significantly increased in remifentanil-ketamine group. First pain scores recordings in arrival to (PACU) were significantly less in remifentanil-ketamine group than remifentanil group and the time passed to first patient controlled analgesia (PCA) demand dose was increased in remifentanil-ketamine group. The first 24 h morphine consumption was 38 +/- 17 and 28 +/- 10 mg (mean +/- SD) in remifentanil and remifentanil-ketamine groups, respectively. CONCLUSIONS: These data demonstrate that during posterior spinal fusion surgery in children, the combination of ketamine and remifentanil infusions as TIVA may provide hemodynamic stability, satisfactory surgical requirements with reliable electrophysiological monitoring and adequate post operative pain relief supplemented by PCA morphine.     

Remifentanil versus morphine analgesia and sedation for mechanically ventilated critically ill patients: a randomized double blind study

BACKGROUND: The rapid onset and offset of action of remifentanil could make it quickly adjustable to the required level of sedation in critically ill patients. The authors hypothesized that the efficacy of a remifentanil-based regimen was greater than that of a morphine-based regimen. METHODS: Forty intent-to-treat patients were randomly allocated to receive a blinded infusion of either remifentanil 0.15 microg x kg(-1) x min(-1) or morphine 0.75 microg x kg(-1) x min(-1). The opioid infusion was titrated, in the first intent, to achieve optimal sedation defined as Sedation Agitation scale of 4. A midazolam open-label infusion was started if additional sedation was required. RESULTS: The mean percentage hours of optimal sedation was significantly longer in the remifentanil group (78.3 +/- 6.2) than in the morphine group (66.5 +/- 8.5). This was achieved with less frequent infusion rate adjustments (0.34 +/- 0.25 changes/h) than in the morphine group (0.42 +/- 0.22 changes/h). The mean duration of mechanical ventilation and extubation time were significantly longer in the morphine group (18.1 +/- 3.4 h, 73 +/- 7 min) than in the remifentanil group (14.1 +/- 2.8 h, 17 +/- 6 min), respectively. Remifentanil mean infusion rate was 0.13 +/- 0.03 microg x kg(-1) x min(-1), whereas morphine mean infusion rate was 0.68 +/- 0.28 microg x kg(-1) x min(-1). More subjects in the morphine group (9 of 20) than in the remifentanil group (6 of 20) required midazolam. The incidence of adverse events was low and comparable across the two treatment groups. CONCLUSIONS: A remifentanil-based regimen was more effective in the provision of optimal analgesia-sedation than a standard morphine-based regimen. The remifentanil-based regimen allowed a more rapid emergence from sedation and facilitated earlier extubation.     

Sublingual morphine may be a suitable alternative for pain control in children in the postoperative period

The purpose of this pilot study was to compare the effects of sublingual morphine with intravenous morphine in the treatment of postoperative pain following adenotonsillectomy in children. Twenty-nine children scheduled for adenotonsillectomy were randomly assigned to group 1 (n=14) receiving 0.1 mg x kg(-1) sublingual morphine and group 2 (n=15) 0.1 mg x kg(-1) intravenous morphine followed by 1 mg x kg(-1) diclofenac rectally in both groups after induction of anaesthesia. Postoperatively, time to first eye opening, sedation score, pain score, time for further analgesia requests and incidence of nausea and vomiting were recorded. There was no statistical significant difference in any of these parameters between the two groups. The results suggest that sublingual morphine may be a suitable alternative to various other routes of opioid administration in children, but further investigations of the sublingual route of administration of opioids in children are required.     

Diclofenac or acetaminophen for analgesia in paediatric tonsillectomy outpatients

BACKGROUND: In order to establish an effective drug regimen, we compared the analgesic efficacy of oral diclofenac and high-dose acetaminophen on pain after tonsillectomy. METHODS: In this randomised, double-blind study 48 children, 5 to 15 years of age, following tonsillectomy were assigned to receive either diclofenac 2-3 mg kg(-1) 24 h(-1) (n=24) or acetaminophen 90 mg kg(-1) 24 h(-1) (n=24) for the first three days after surgery. Postoperative pain was assessed by self-report each day before scheduled medication at 7 h, 12 h, 18 h and 23 h. RESULTS: The number of children rating severe pain was high in both the diclofenac group, 5-50%, and in the acetaminophen group, 12-58% during the three day study period. Pain scores in the diclofenac group were only significantly lower at 12 h on day 1-3 compared to pain scores in the acetaminophen group (P<0.05). None of the children in the diclofenac group experienced any episodes of nausea/vomiting compared to 9 children in the acetaminophen group on day 1. The incidences of nausea/vomiting increased with pain (P<0.05). None of the 48 children experienced any episodes of bleeding. CONCLUSIONS: This study indicates that diclofenac was no more effective than high-dose acetaminophen (90 mg vs. 60 mg kg(-1) 24 h(-1)) for analgesia, but resulted in a lower incidence of nausea and vomiting in patients following tonsillectomy.     

Remifentanil infusion for cleft palate surgery in young infants

BACKGROUND: The residual depressant effect of opioid is a major concern in infants scheduled for cleft palate repair. Remifentanil is associated with a fast and predictable recovery, independent of age. METHODS: About 40 infants in the 2-12 month age range were prospectively enrolled in this open study, to receive either remifentanil (infusion starting at 0.25 microg x kg(-1) x min(-1)) or sufentanil as part of a balanced anaesthesia regimen. Isoflurane was maintained at an endtidal concentration of 1.2% in oxygen and nitrous oxide and the opioid dosing was titrated to autonomic responses. Postoperative pain relief was provided by morphine infusion. Morphine administration started intraoperatively in the remifentanil group. RESULTS: Consistent haemodynamic stability was achieved throughout surgery in both groups. Infants of the remifentanil group required, on average, lower concentrations of isoflurane than children of the sufentanil group (1.2 +/- 0.2% vs 1.7 +/- 0.3%, P < 0.001). The median time from last suture to tracheal extubation was 12.5 min (5-25 min) in the remifentanil group and 15.0 min (10-30 min) in the sufentanil group. There was no evidence of hyperalgesia or enhanced morphine consumption in the remifentanil group compared with the sufentanil group. Postoperative pain scores were even lower in the remifentanil group, compared with the sufentanil group, soon after arrival in the postanaesthesia care unit. CONCLUSIONS: Remifentanil-based anaesthesia appeared well suited for primary cleft palate repair in young infants.     

Study of Three Different Doses of Epidural Neostigmine Coadministered with Lidocaine for Postoperative Analgesia

Background: Intrathecal neostigmine produces analgesia in volunteers and patients. However, the use of epidural neostigmine has not been investigated. The purpose of the current study was to define the analgesic effectiveness of epidural neostigmine coadministered with lidocaine and side effects in patients after minor orthopedic procedures.

Methods: After Institutional Review Board approval and informed consent, 48 patients (n = 12) undergoing knee surgery were randomly allocated to one of four groups and studied in a prospective way. After 0.05-0.1 mg/kg intravenous midazolam premedication, patients were randomized to receive 20 mg intrathecal bupivacaine plus epidural lidocaine (85 mg) with saline (control group); 1 [micro sign]g/kg epidural neostigmine (1 [micro sign]g group); 2 [micro sign]g kg epidural neostigmine (2 [micro sign]g group); or 4 [micro sign]g/kg epidural neostigmine (4 [micro sign]g group). The concept of the visual analog scale, which consisted of a 10-cm line with 0 equaling "no pain at all" and 10 equaling "the worst possible pain" was introduced. Post-operatively, pain was assessed using the visual analog scale, and intramuscular 75 mg diclofenac was available at patient request.

Results: Groups were demographically the same and did not differ in intraoperative characteristics (blood pressure, heart rate, ephedrine consumption, oxyhemoglobin saturation, sensory loss before start of surgery, or duration of sensory motor block). The visual analog scale score at first rescue analgesic and the incidence of adverse effects were similar among groups (P > 0.05). The time (min +/- SD) to first rescue analgesic was as follows: control group: 205 +/- 48; 1-[micro sign]g group: 529 +/- 314; 2-[micro sign]g group: 504 +/- 284; 4-[micro sign]g group: 547 +/- 263 (P < 0.05). The analgesic consumption (number of intramuscular diclofenac injections [mean, 25th-75th percentile]) in 24 h was as follows: control group: 3 [3 or 4]; 1-[micro sign]g group: 1[1 or 2]; 2-[micro sign]g group: 2[1 or 2]; 4-[micro sign]g group: 2[1-3](P < 0.05). The 24-h-pain visual analog scale score (cm +/- SD) that represents the overall impression for the last 24 h was as follows: control group: 5 +/- 1.6; 1-[micro sign]g group: 1.6 +/- 1.8; 2-[micro sign]g group: 1.4 +/- 1.6; 4-[micro sign]g group: 2.2 +/- 1.9 (P < 0.005). The incidence of adverse effects was similar among groups (P > 0.05).     

Development of acute opioid tolerance during infusion of remifentanil for pediatric scoliosis surgery

We tested the hypothesis that continuous intraoperative infusion of remifentanil is associated with the development of clinically relevant acute opioid tolerance in adolescents undergoing scoliosis surgery. Thirty adolescents were randomly assigned to receive an intraoperative analgesic regimen consisting of continuous remifentanil infusion or intermittent morphine alone. Postoperative analgesic consumption was assessed with a patient-controlled analgesia device that was used to self-administer morphine. Cumulative postoperative morphine consumption, pain scores, and sedation scores were recorded by a blinded investigator every hour for the first 4 h postoperatively and then every 4 h for a total of 24 h. Cumulative morphine consumption in the remifentanil group was significantly more than that in the morphine group at each time point in the initial 24 h after surgery (P < 0.0001). At 24 h after surgery, cumulative morphine consumption was 30% greater in the remifentanil group (1.65 +/- 0.41 mg/kg) than in the morphine group (1.27 +/- 0.32 mg/kg) (95% confidence interval for the difference, 0.11 to 0.65 mg/kg). Differences in pain and sedation scores were not statistically significant. These data suggest that intraoperative infusion of remifentanil is associated with the development of clinically relevant acute opioid tolerance in adolescents undergoing scoliosis surgery.     

Peroperative titration of morphine improves immediate postoperative analgesia after total hip arthroplasty

PURPOSE: To determine the Influence of peroperative titrated morphine on postoperative pain control. METHODS: Forty patients received general anesthesia for total hip arthroplasty (THA) and were divided into two groups of 20. In the Peroperative group (Perop group;) morphine was titrated at the end of surgery (3 mg i.v. every 5 or 10 min) in spontaneously breathing intubated patients, until the respiratory rate (RR) decreased. No morphine was administered to Postop group. In the Post Anesthesia Care Unit (PACU) patients in Perop and Postop groups received morphine until adequate pain relief VAS < or = 30 mm. Patients used patient-controlled analgesia (PCA) for the next 24 hr. In the PACU, the delay for analgesia, doses of morphine used and incidence of side effects were recorded. RESULTS: In the Perop group, patients received 10.3 +/- 1.3 mg (2-20 mg) as peroperative titration and had achieved adequate analgesia more rapidly than in the Postop group (42 +/- 7 min vs 76 +/- 7 min); P = 0.0026). Analgesia in the PACU in the Postop group required larger doses of morphine (15.4 +/- 1.5 mg;) than in the Perop group (7.3 +/- 1.3 mg; P = 0.0004). The respiratory rate decrease during peroperative morphine titration was correlated to the morphine dose needed in the PACU (P = 0.035). Respiratory depression in the PACU was more common in the Postop group than in the Perop group (five patients vs no patient P = 0.017). CONCLUSION: This study demonstrated that the peroperative administration of morphine can facilitate immediate postoperative pain management.     

Prophylactic Use of Epidural Mepivacaine/Morphine, Systemic Diclofenac, and Metamizole Reduces Postoperative Morphine Consumption after Major Abdominal Surgery

Background: Surgical trauma induces nociceptive sensitization leading to amplification and prolongation of postoperative pain. While preemptive analgesic treatment with numerous agents has been successful in experimental animals, results of human studies remain conflicting. The authors used a multimodal approach for preemptive analgesia before abdominal surgery: diclofenac and metamizole inhibit prostaglandin synthesis, thus influencing peripheral sensitization; epidural local anesthetics induce conduction block, epidural opioids inhibit nociceptive synaptic transmission, and metamizole induces descending inhibition. The interaction of these drugs might suppress spinal nociceptive sensitization and postoperative analgesic demand.

Methods: One hundred forty-two patients scheduled for major abdominal surgery were randomly assigned to one of three groups and studied prospectively. Epidural catheters in groups 1 and 2 were placed at interspaces T8-T10, the position of the catheter was confirmed by epidurography, and sensory testing after administration of 5 ml mepivacaine 1%. Group 1 received 75 mg intramuscular diclofenac, 1000 mg intravenous metamizole, 5.3+/-1 mg epidural morphine, and 15-20 ml mepivacaine 1% 85+/-41 min before skin incision. Epidural analgesia was maintained by injections of 0.1 ml *symbol* kg sup -1 *symbol* h sup -1 mepivacaine 1%. Group 2 patients received the balanced analgesia regimen before wound closure (221+/-86 min after skin incision). Group 3 patients did not receive any study substances. General anesthesia was induced with 5 mg/kg thiopental and 2 micro gram/kg fentanyl and maintained with enflurane and nitrous oxide. Postoperative analgesia consisted of patient-controlled intravenous morphine over 5 days.

Results: Median visual analog scale pain intensities were < 3 cm and did not differ among the groups. Morphine consumption per hour on postoperative day 2 was 0.8+/-0.1 mg/h (group 1) < 1.2+/- 0.1 mg/h (group 2) = 1.1+/-0.1 mg/h (group 3) and cumulative morphine consumption (in mg) on the morning of day 5 was 95+/-9 (group 1) < 111+/-11 (group 2) < 137+/-10 (group 3).     

Effet d’épargne morphinique de la kétamine au cours de l’amygdalectomie chez l’enfant

Introduction

In the adult population, Ketamine is currently used as an antihyperalgesic and opioid-sparing agent during the perioperative period. However, for doses of ketamine up to 0.5 mg/kg, these effects have not been found in pediatric population. The aim of the present study was to evaluate the efficacy of a preoperative bolus of 1 mg/kg of ketamine on postoperative pain intensity and morphine consumption in children undergoing tonsillectomy.

Methods

We have undertaken a retrospective comparison of 60 consecutive children operated for tonsillectomy in our institution before (first 30 patients) and after (last 30 patients) the introduction of a preoperative bolus of 1 mg/kg of ketamine. Data collected were: age, ASA score, dose of intraoperative sufentanil, OPS score during PACU stay and the first postoperative day, morphine consumption during PACU stay and the first postoperative day, psychodysleptic manifestations, pain at first solid oral intake and postoperative respiratory complications or haemorrhage.

Results

No difference was found between the two groups in terms of demographic characteristics. Perioperative doses of sufentanil, postoperative opioid consumption or pain score in PACU or during 24 hours were similar between the two groups. The two groups did not differ in terms of pain at first oral intake, or other adverse effects.

Conclusion

These results suggest that 1 mg/kg of ketamine administered right after anaesthesia induction in children undergoing tonsillectomy did not result in an opioid sparing effect.     

Rectally administered diclofenac (Voltaren) reduces vomiting compared with opioid (morphine) after strabismus surgery in children

BACKGROUND: Nausea, vomiting and pain are common complications after strabismus surgery in children. Diclofenac, a non-steroid anti-inflammatory drug, is widely used to treat acute and chronic pain but there are few reports of its use given rectally in children undergoing strabismus surgery. This open randomised study was designed to investigate the analgesic and anti-emetic properties of rectally administered diclofenac compared with opioid (morphine) given i.v. in connection with strabismus surgery in children. METHODS: After obtaining approval from the local ethics committee and written informed consent from the parents, 50 ASA class I-II children, 4-16 years of age, were randomised to receive either rectally administered diclofenac (Voltaren) 1 mg/kg or i.v. opioid (morphine) 0.05 mg/kg perioperatively. The children were consecutively operated upon from May 1999 to January 2001. Anaesthesia was induced with fentanyl and propofol and maintained with propofol. Nitrous oxide was omitted. The postoperative pain was assessed after arrival at the post anaesthesia care unit (PACU) by using the validated Wong and Baker scale (FACES) Pain Rating Scale. Postoperative nausea and vomiting (PONV) was assessed by measuring the frequency of vomiting and the degree of nausea. RESULTS: In the diclofenac group the incidence of PONV during the first 24 h was 12% (of which one child had severe vomiting). The incidence of PONV was much higher, 72% (P = 0.0000), in the morphine group, where 56% of the children also had severe vomiting. There were no difference in pain score between the two groups. Recovery time at the PACU was longer (P < 0.002) and the postoperative analgesic requirement higher in the morphine group (10 vs. 5 children). No children needed overnight admission to the hospital. CONCLUSION: Diclofenac given rectally is an effective analgesic for this kind of surgery and gives less postoperative nausea than i.v. morphine. No serious adverse events were observed.     

A Comparison of Remifentanil and Morphine Sulfate for Acute Postoperative Analgesia after Total Intravenous Anesthesia with Remifentanil and Propofol

Background: The transition from remifentanil intraoperative anesthesia to postoperative analgesia must be planned carefully due to the short duration of action (3-10 min) of remifentanil hydrochloride, a potent, esterase-metabolized micro-opioid agonist. This study compared the efficacy and safety of transition regimens using remifentanil or morphine sulfate for immediate postoperative pain relief in patients who had surgery under general anesthesia with remifentanil/propofol.

Methods: One hundred fifty patients who had received open-label remifentanil and propofol for intraoperative anesthesia participated in this multicenter, double-blind, double-dummy study and were randomly assigned to either the remifentanil (R) group or the morphine sulfate (M) group. Twenty minutes before the anticipated end of surgery, the propofol infusion was decreased by 50%, and patients received either a placebo bolus (R group) or a bolus of 0.15 mg/kg morphine (M group). At the end of surgery, the propofol and remifentanil maintenance infusions were discontinued and the analgesic infusion was started: either 0.1 micro gram [center dot] kg sup -1 [center dot] min sup -1 remifentanil (R group) or placebo analgesic infusion (M group). During the 25 min after tracheal extubation, remifentanil titrations in increments of 0.025 micro gram [center dot] kg sup -1 [center dot] min sup -1 and placebo boluses (R group), or 2 mg intravenous morphine boluses and placebo rate increases (M group) were administered as necessary at 5-min intervals to control pain. Patients received the 0.075 mg/kg intravenous morphine bolus (R group) or placebo (M group) at 25 and 30 min after extubation, and the analgesic infusion was discontinued at 35 min. From 35 to 65 minutes after extubation, both groups received 2-6 mg open-label morphine analgesia every 5 min as needed.

Results: Successful analgesia, defined as no or mild pain with adequate respiration (respiratory rate [RR] >or= to 8 breaths/min and pulse oximetry >or= to 90%), was achieved in more patients in the R group than in the M group (58% vs. 33%, respectively) at 25 min after extubation (P < 0.05). The median remifentanil rate for successful analgesia was 0.125 micro gram [center dot] kg sup -1 [center dot] min sup -1 (range, 0.05-0.23 micro gram [center dot] kg sup -1 [center dot] min sup -1), and the median number of 2-mg morphine boluses used was 2 (range, 0-5 boluses). At 35 min after extubation, >or= to 74% of patients in both groups experienced moderate to severe pain. Median recovery times from the end of surgery were similar between groups. Transient respiratory depression, apnea, or both were the most frequent adverse events (14% for the R group vs. 6% for the M group; P > 0.05).     

Pharmacokinetics of oral diclofenac and acetaminophen in children after surgery

BACKGROUND: Our aim was to study the pharmacokinetics and pain scores following administration of single oral doses of either diclofenac or high-dose acetaminophen (paracetamol). METHODS: In the morning, the day after tonsillectomy, children 5-15 years of age were randomized in a double-blind manner to receive either diclofenac 1-2 mg.kg-1 (n=11) or acetaminophen 22.5 mg.kg-1 (n=10). Postoperative pain was assessed by self-report and blood samples were drawn every 30 min for 4 h after medication. RESULTS: Large interindividual differences in maximum plasma diclofenac concentrations (Cmax) were found. Mean Cmax was 2.4+/-1.3 microg.ml-1 and mean tmax was 2+/-0.5 h. No significant reduction in pain score with diclofenac was seen at any of the assessments during the study period. Eight of 10 children achieved Cmax of acetaminophen within the 10-20 microg.ml-1 antipyretic range. Mean tabs was 0.7+/-0.3 h and mean Cmax and tmax were 12.7+/-3.8 microg ml-1 and 1.4+/-0.5 h, respectively. No significant reduction in pain score with acetaminophen was seen at any of the assessments during the study period. CONCLUSIONS: The achieved concentrations of diclofenac and acetaminophen were not able to significantly reduce the children's pain score during the 5 h postingestion study period. Analgesic plasma acetaminophen concentrations may be higher than those required for antipyresis.     

Analgesic effect of epidural neostigmine after abdominal hysterectomy

STUDY OBJECTIVE: To evaluate the effects of epidurally administered neostigmine on pain after abdominal hysterectomy. DESIGN: Prospective, randomized, double-blind study. SETTING: Teaching hospital. PATIENTS: 45 ASA physical status I adult patients scheduled for abdominal hysterectomy. INTERVENTIONS: All patients received identical general and epidural anesthesia. At the end of the surgery, they received epidural bupivacaine (10 mg) with either saline (control group, n = 15), 5 micro g/kg (5-micro g group, n = 15), or 10 micro g/kg neostigmine (10-micro g group, n = 15). Postoperatively, 50 mg diclofenac suppository was given for pain relief on patient demand. MEASUREMENTS AND MAIN RESULTS: The time to first diclofenac administration and the number of times diclofenac was required during the first 24 postoperative hours were recorded. Pain was assessed using a 10-cm visual analog pain scale (VAS) at rest at the first diclofenac request, and at 15 and 24 hours after surgery. The time to first diclofenac administration was significantly longer (p < 0.05) in the 10-micro g group (223 +/- 15 min) than in the control (78 +/- 17 min) or 5-micro g groups (88 +/- 18 min). However, epidural neostigmine at both doses did not reduce the number of postoperative diclofenac administrations. There were no differences in VAS among the three groups. CONCLUSIONS: Epidural neostigmine of 10 micro g/kg in bupivacaine provides a longer duration of analgesia than does bupivacaine alone or with 5 micro g/kg of neostigmine after abdominal hysterectomy.