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Background Severe pain often accompanies major spine surgery. Opioids are the cornerstone of postoperative pain management but their use can be limited by numerous side effects. Several studies claim that adjuvant treatment with intravenous (IV) ketamine reduces opioid consumption and pain after back surgery. However, the exact role of ketamine for this indication is yet to be elucidated. We compared 2 different doses of S-ketamine with placebo on postoperative analgesic consumption, pain, and adverse events in adult, opioid-naive patients after lumbar fusion surgery. Methods One hundred ninety-eight opioid-naive patients undergoing lumbar spinal fusion surgery were recruited to this double-blind trial and randomly assigned into 3 study groups: Group C (placebo) received a preincisional IV bolus of saline (sodium chloride [NaCl] 0.9%) followed by an intraoperative IV infusion of NaCl 0.9%. Both groups K2 and K10 received a preincisional IV bolus of S-ketamine (0.5 mg/kg); in group K2, this was followed by an intraoperative IV infusion of S-ketamine (0.12 mg/kg/h), while in group K10, it was followed by an intraoperative IV infusion of S-ketamine (0.6 mg/kg/h). Postoperative analgesia was achieved by an IV patient-controlled analgesia (IV PCA) device delivering oxycodone. The primary end point was cumulative oxycodone consumption at 48 hours after surgery. The secondary end points included postoperative pain up to 2 years after surgery, adverse events, and level of sedation and confusion in the immediate postoperative period. Results The median [interquartile range (IQR)] cumulative oxycodone consumption at 48 hours was 154.5 [120] mg for group K2, 160 [109] mg for group K10, and 178.5 [176] mg for group C. The estimated difference was -24 mg between group K2 and group C (97.5% confidence interval [CI], -73.8 to 31.5; P = .170) and -18.5 mg between group K10 and C (97.5% CI, 78.5-29.5; P = .458). There were no significant differences between groups.Postoperative pain scores were significantly lower in both ketamine treatment groups at the fourth postoperative hour but not later during the 2-year study period.The higher ketamine dose was associated with more sedation. Otherwise, differences in the occurrence of adverse events between study groups were nonsignificant. Conclusions Neither a 0.12 nor a 0.6 mg/kg/h infusion of intraoperative IV S-ketamine was superior to the placebo in reducing oxycodone consumption at 48 hours after lumbar fusion surgery in an opioid-naive adult study population. Future studies should assess ketamine's feasibility in specific study populations who most benefit from reduced opioid consumption.

UNLABELLED The cause of transient neurologic symptoms (TNSs) after lidocaine spinal anesthesia remains unclear. It has been proposed that early ambulation after spinal anesthesia contributes to the development of TNSs. We evaluated the influence of ambulation time on the occurrence of TNSs after spinal anesthesia with 50 mg of 2% plain lidocaine for knee arthroscopy. One-hundred-twenty patients undergoing knee arthroscopy (ASA physical status 1-2) were randomized into 3 groups, i.e., early (Group E), 6-h (Group 6-h), or late ambulation (Group L) groups. In Group E, ambulation was allowed as early as possible after regression of spinal block (on average 229 +/- 21 min; range, 135-247 min). In Group 6-h, the patients remained in bed for approximately 6 h after the block and in Group L until the next morning. The patient groups were comparable with respect to demographic, anesthetic, and surgical variables. The overall incidence of TNSs was 16%. TNSs occurred in 3 patients of Group E (7.5%), in 11 patients of Group 6-h (28%), and in 5 patients of Group L (13%). No significant differences were detected between the patients with and without TNSs. Early ambulation was not found to be a risk factor for TNSs after spinal anesthesia with 50 mg of 2% lidocaine. IMPLICATIONS This study shows that early ambulation time does not increase the incidence of transient neurologic symptoms after spinal anesthesia with 50 mg of 2% lidocaine for elective knee arthroscopy.

Objective: In Europe, the day-case tonsillectomy rate in children is slowly increasing, but whether parents really want this rapid discharge of their child is questionable. The fear is that aftercare might fall solely on community care. The aim of this prospective study was to introduce pediatric day-case tonsillectomy to our hospital and to determine parents’ attitudes to this procedure. The other interest centered on consultation rates within the 2-week recovery period. Methods: One hundred children aged 3–16 years had day-case tonsillectomy (38) or adenotonsillectomy (62). Peri-operative and post-operative complications were recorded. Parents were phoned the next day and 1–4 months after the operation. Parents’ opinions of day-case surgery and consultations with healthcare professionals during the 2-week recovery period were recorded. Results: Ninety children went home the day of the operation. Vomiting was the most frequent complication. No primary hemorrhages occurred. Called the next day, 100% of parents felt that their children were better served spending their first night at home as compared with staying in hospital. Called 1–4 months later, 94.5% of parents still thought this way. In the 2-week recovery period following the tonsillectomy, 13% of patients visited a physician and 17% called for information. These numbers include patients with secondary hemorrhage. If these are excluded, 5% of patients visited a physician and 13% called for advice. Children were taken back to hospital only due to secondary hemorrhage. Conclusions: Most parents considered day-case tonsillectomy to be suitable for their family. Consultation rates were low. Careful patient selection and adequate pre-operative information are prerequisites for day-case tonsillectomy.

Nociceptive pain serves the useful purpose of alerting the body to potential or actual tissue damage. By contrast, neuropathic pain that results from injury or damage to the nervous system persists long after all signs of the original injury have disappeared. Neuropathic pain presents a significant clinical problem as it responds poorly to classical analgesics such as non-steroidal anti-inflammatory drugs (NSAIDs) and to opioids; there is also no single, uniformly well-tolerated drug that is reliably helpful. Treatment currently involves the use of anticonvulsant and/or antidepressant drugs. Electrophysiological experiments on dorsal root ganglion and spinal cord neurons of nerve-injured experimental animals are yielding new information on the pathophysiology of neuropathic pain. Analysis of actions of various neuropeptides and neurotransmitters in these models has helped to explain the poor efficacy of opioids and suggests new therapeutic approaches to the management of neuropathic pain. Drugs that stimulate α2-c-adrenoceptors or that mimic the actions of neuropeptide Y, galanin, or the opioid-like peptide, nociceptin, may be of use in this regard. Drug Dev. Res. 54:140–153, 2002. © 2002 Wiley-Liss, Inc.

To compare the induction and recovery characteristics of sevoflurane anesthesia induced with either propofol or sevoflurane in pediatric outpatients.Fifty-two children, aged 1-3 yr, presenting for ambulatory adenoidectomy were randomly allocated to receive 3 mg.kg-1 propofol i.v. or sevoflurane 8% inspired concentration for induction of anesthesia. Tracheal intubation was facilitated with 0.2 mg.kg-1 mivacurium. Anesthesia was maintained with nitrous oxide/oxygen (FiO2 0.3) and sevoflurane approximately 3-5% inspired concentration with controlled ventilation. Intubation was assessed by an anesthetist blinded to the induction method. Recovery characteristics were compared using the modified Aldrete scoring system, the Pain/Discomfort scale and measuring specific recovery times. A postoperative questionnaire was used to evaluate the children's well-being at home.Intubating conditions were similar in both groups. Emergence from anesthesia occurred earlier with sevoflurane for induction than with propofol (11 +/- 4 vs 17 +/- 7 min (mean +/- SD), P = 0.0002). More children in the sevoflurane group achieved full points on the modified Aldrete scoring system during the first 20 min after anesthesia (P0.05). However, children in the sevoflurane group scored higher in the Pain/Discomfort scale at 10 min after anesthesia (P = 0.04) and were given postoperative analgesics earlier than children in the propofol group (13 +/- 5 min vs 18 +/- 11 min, P = 0.03). The time to meet discharge criteria and recovery at home were similar.Induction of sevoflurane anesthesia with propofol for day-case adenoidectomy results in longer, but more calm, early recovery but does not delay discharge or affect recovery at home.

Chronic pain patients often require maintenance medication for ongoing symptom relief. Two of the most common classes of drugs used in this setting are opioids and nonsteroidal antiinflammatories. Both types of medication are being prescribed with increasing frequency and consequently complications and side-effects are being encountered more often. A role for opioids is beginning to emerge in the chronic benign pain patient population. Choosing appropriate patients, setting ground rules for medication use, and being aware of potential problems are all critical in minimizing complications. Nonsteroidal antiinflammatories are used both with and without physician supervision. The consumption of these medications is widespread despite potentially serious complications. Awareness of the pitfalls encountered with these medications should lead to safer outcomes and increased physician and patient satisfaction.

The influence of different clinically used alkaline buffers on cytoplasmic pH in normal as well as acidotic rat myocardial cells was investigated in this study by means of the fluorescent intracellular probe 2',7'-bis-(carboxyethyl)-5,6-carboxyfluorescein acetoxymethyl ester (BCECF-AM). It was shown that both sodium bicarbonate and Tris buffer mixture (Tribonat) caused a significant and dose-dependent acidification of the cytoplasm of suspended myocardial cells with normal initial intracellular pH. This decrease was followed by a slow increase during the observation period. The initial cytoplasmic pH value was more easily reached when Tris buffer mixture was used. Ringer's acetate also caused a decrease of intracellular pH, but this change persisted and was further amplified during the experiment. Carbicarb in larger dosages as well as pure trometamol (Tris) caused a pronounced dose-dependent and lasting intracellular alkalinization. Intracellular acidosis was achieved by preincubating the cells in sodium acetate. Addition of sodium bicarbonate caused an initial and dose-dependent acidification of the cytoplasm followed by a slow increase to values slightly above the induced acidosis. In contrast, Tris buffer mixture showed a tendency towards an initial acidification only when larger dosages were used, and correction of the induced acidosis was possible by use of moderate to large volumes. Ringer's acetate produced a lasting and dose-dependent decrease of cytoplasmic pH, while Carbicarb and pure trometamol caused an immediate, pronounced and persistent alkalinization. Myocardial cells with low initial cytoplasmic pH due to preincubation in an acid buffer also showed an early decrease of intracellular pH after addition of sodium bicarbonate and Tris buffer mixture. In the case of sodium bicarbonate correction of the acid-base disturbance was not achieved during the observation period, while this was accomplished by use of larger volumes of Tris buffer mixture. Carbicarb in larger volumes caused an increase in intracellular pH. The most significant and persistent increases of cytoplasmic pH was achieved by use of pure trometamol. In conclusion, the present in vitro study implies that Tris buffer mixture (Tribonat) is well-suited for correction of intracellular acidosis since it acts without causing a pronounced initial intracellular acidosis or a later potentially hazardous huge cytoplasmic alkalinization.

Postoperative agitation is a common problem after sevoflurane anesthesia in children. In the present study, we evaluated if tropisetron or clonidine could reduce the incidence of postoperative agitation after day case adenoidectomy in small children. We included 75 unpremedicated children aged 1-7 yr who were randomly assigned to receive either placebo, tropisetron (0.1 mg/kg) or clonidine (1.5 microg/kg) after anesthesia induction. Anesthesia was induced and maintained with sevoflurane. Patients also received alfentanil (20 microg/kg) and diclofenac (1 mg/kg). Postoperative pain was treated with IV oxycodone (0.05 mg/kg). Time to achieve discharge criteria was recorded. Modified pain/discomfort scale was used assess the postoperative behavior. The incidence of postoperative agitation was significantly less (32%, 8/25 patients) in the tropisetron group compared with placebo (62%, 16/26 patients), P < 0.05). Clonidine could not prevent agitation (incidence 54%, 13/24). No adverse effects were noted during the study. Discharge times were similar between the groups (between 80 and 99 min on average). In conclusion, tropisetron 0.1 mg/kg significantly reduced the incidence of postoperative agitation after sevoflurane anesthesia. Clonidine 1.5 microg/kg did not differ from placebo with respect to postoperative agitation.

Background The study was designed to examine a new method of confirming proper caudal needle placement using nerve stimulation. Methods Thirty-two pediatric patients were studied. A 22-gauge insulated needle was inserted into the caudal canal via the sacral notch until a "pop" was felt. The needle placement was classified as correct or incorrect depending upon the presence or absence of anal sphincter contraction (S2-S4) to electrical simulation (1 to 10 mA). Results Three patients were excluded, two because they inadvertently received neuromuscular blockers and one because the patient's anatomy precluded any attempt at a caudal block. The sensitivity and specificity of the test were both 100% in predicting clinical outcomes of the caudal block. Six patients had a negative stimulation test after the first attempt to place the needle. Four of these went on to receive a second attempt of needle insertion after a subcutaneous bulge or resistance to local anesthetic injection were observed. Following needle reinsertion, positive stimulation tests were elicited. These patients received the local anesthetic injection with ease and had good analgesia postoperatively. No attempt was made to reinsert the needle in the remaining two patients with a negative stimulation test, as they did not show subcutaneous bulge or resistance upon injection. These patients had poor analgesia postoperatively. The positive predictive value of the test was greater than the presence of a "pop" alone (P < 0.05) but not significantly different (P = 0.492) over the presence of "pop" and easy injection. Conclusion This test may be used as a teaching and adjuvant tool in performing caudal block.

UNLABELLED: We studied the effect of oral premedication with midazolam on the recovery characteristics of sevoflurane anesthesia in small children. In a randomized, double-blinded study, 60 children (1-3 yr, ASA physical status I or II) undergoing ambulatory adenoidectomy received either midazolam 0.5 mg/kg (Group M) or placebo (Group P) PO approximately 30 min before the induction of anesthesia. All children received atropine 0.01 mg/kg IV and alfentanil 10 microg/kg IV before the induction of anesthesia with sevoflurane up to 8 vol% inspired concentration in N2O 67% in O2. Tracheal intubation was facilitated with mivacurium 0.2 mg/kg. Anesthesia was continued with sevoflurane adjusted to maintain hemodynamic stability. In the postanesthesia care unit, predetermined recovery end points (emergence, recovery, discharge) were recorded. A pain/ discomfort scale was used to determine the quality of recovery. A postoperative questionnaire was used to evaluate the well-being of the patient at home 24 h after surgery. Emergence (spontaneous eye opening), recovery (full points on the modified Aldrete scale), and discharge were achieved later in Group M than in Group P (15+/-6 vs. 11+/-3 min [P = 0.002], 25+/-17 vs. 16+/-6 min [P = 0.01], and 80+/-23 vs. 70+/-23 min [P = 0.03]). Side effects, postanesthetic excitement, and analgesic treatment did not differ significantly between groups. At home, more children in Group P (30%) experienced disturbed sleep during the night compared with those in Group M (4%) (P = 0.007). IMPLICATIONS: In this randomized, double-blinded, placebo-controlled study, premedication with midazolam 0.5 mg/kg PO delayed recovery in children 1-3 yr of age after brief (