Comparison between newer local anesthetics for myofascial pain syndrome management.

Myofascial pain syndromes are characterized by the presence of painful loci within muscles, tendons or ligaments, called trigger points. Infiltration of these points with local anesthetics is often used as a treatment modality. The aim of the study was to comparatively evaluate 0.25% levobupivacaine and 0.25% ropivacaine for trigger point injection regarding pain on injection, treatment efficacy and duration of symptoms remission. Sixty-eight patients, suffering from myofascial pain syndromes, were randomly assigned to two groups to receive either levobupivacaine or ropivacaine for trigger-point injection. After completion of the procedure, patients were asked to rate pain during injection and efficacy of the treatment, based on immediate relief. Two weeks later, they were asked about the duration of this relief. Statistical analysis did not reveal significant differences between groups with respect to pain during injection, efficacy of the treatment and duration of pain relief. The two local anesthetics seem to be equally effective for trigger point infiltration.

Rocuronium duration of action under sevoflurane, desflurane or propofol anaesthesia.

BACKGROUND AND OBJECTIVE: We conducted a prospective randomized study to evaluate whether the duration of action of a single bolus dose of rocuronium is influenced by maintenance of anaesthesia with sevoflurane, desflurane or propofol infusion. METHODS: Fifty-seven ASA I-II patients undergoing elective abdominal surgery were enrolled in this study. Anaesthesia was induced with thiopental 3-5 mg kg(-1) or propofol 2.5 mg kg(-1) and fentanyl 5 microg kg(-1) and tracheal intubation was facilitated with rocuronium 0.9 mg kg(-1). Thereafter patients were randomly allocated to three different groups to receive sevoflurane, desflurane or propofol for maintenance of anaesthesia. Recovery of neuromuscular function was monitored by single twitch stimulation of the ulnar nerve and by recording the adductor pollicis response using accelerometry. Intergroup recovery times to 5% of control value of single twitch were analysed using analysis of variance with Bonferroni correction. RESULTS: The mean (95% confidence interval) recovery time to 5% of control value of single twitch during desflurane anaesthesia was 90.18 (86.11-94.25) min. Significantly shorter recovery times were observed during sevoflurane or propofol anaesthesia, 58.86 (54.73-62.99) min and 51.11 (45.47-56.74) min, respectively (P < 0.001). There were also significant differences in the recovery time between groups receiving desflurane vs. sevoflurane (P < 0.001) and desflurane vs. propofol (P < 0.001). CONCLUSIONS: Desflurane anaesthesia significantly prolongs the duration of action of rocuronium at 0.9 mg kg(-1) single bolus dose, compared to sevoflurane or propofol anaesthesia maintenance regimens.

Large bowel obstruction in women with pelvic malignancies. What is the primary?

BACKGROUND: Large bowel obstruction is occasionally the mode of presentation of advanced colorectal or pelvic malignancies, and a prognostic of poor survival. The choices of treatment range from palliative tube decompression to curative or palliative surgery. METHODS: Twelve out of 500 women with various malignancies and symptomatology of large bowel obstruction were studied. All patients required urgent exploratory laparotomies. RESULTS: The primary site was established intra-operatively to be the colon (2 cases), stomach (2 cases) and ovaries (2 cases). In the remaining 6 cases there was uncertainty about the origin of primary disease. Routine histology and immuno-histochemistry of the specimens revealed the origin of primary malignancy in all cases. CONCLUSIONS: Meticulous histological examination is essential for the establishment of correct diagnosis and selection of the best available treatment in women with pelvic malignancies, presenting with acute bowel obstruction.

Clonidine versus ketamine to prevent tourniquet pain during intravenous regional anesthesia with lidocaine.

BACKGROUND AND OBJECTIVES: Both clonidine and ketamine have been found to prolong the action of local anesthetics through a peripheral mechanism. Our study compares the efficacy of a low dose of clonidine or ketamine separately added to intravenous regional anesthesia (IVRA) with lidocaine to prevent tourniquet pain. METHODS: We conducted a prospective randomized double-blinded study in 45 patients undergoing hand or forearm surgery, with anticipated duration exceeding 1 hour under IVRA. Proximal cuff inflation of a double tourniquet was followed by administration of 40 mL of lidocaine 0.5% and either saline, 1 microg/kg clonidine, or 0.1 mg/kg ketamine. When anesthesia was established, the inflation of the proximal and distal cuff was interchanged. Thereafter, tourniquet pain was rated on a visual analog scale (VAS) every 10 minutes. Intraoperatively, boluses of 25 microg fentanyl were provided for tourniquet pain treatment when required, and total fentanyl consumption was recorded. RESULTS: Patients receiving plain lidocaine persistently reported the highest pain scores among groups (P <.001) 20 minutes after distal cuff inflation. Differences between the groups with additional treatment were noted 50 minutes after distal cuff inflation and until the end of the observation, with significantly lower VAS ratings (P <.001 to P <.01) in ketamine-treated patients. Total fentanyl consumption was significantly decreased by ketamine (70.00 +/- 25.35 microg) or clonidine (136.67 +/- 39.94 microg) compared with the plain lidocaine group (215.33 +/- 52.33 microg) (P <.001 between all groups). CONCLUSIONS: The addition of clonidine 1 microg/kg or ketamine 0.1 mg/kg to lidocaine for IVRA delays the onset of unbearable tourniquet pain and decreases analgesic consumption for tourniquet pain relief, although ketamine has a more potent effect.

Intercostal nerve blockade with a mixture of bupivacaine and phenol enhance the efficacy of intravenous patient-controlled analgesia in the control of post-cholecystectomy pain.

Prolonged nerve conduction blockade has been proposed to result from the summed effects of charged and neutral local anaesthetics. Thirty-seven patients were randomly allocated to receive intravenous patient-controlled analgesia alone or combined with intercostal blockade (T7-T11) with a mixture of 0.45% bupivacaine and 0.6% phenol for post-cholecystectomy analgesia. Adequacy of pain relief was measured by patient scores on a 10-cm visual analogue scale and by dose-demand ratio, amounts of loading dose and total consumption of morphine and also the duration of patient-controlled analgesia in each group. No differences were found between groups in post-operative scores, dose-demand ratios and loading doses of morphine. However, in the combined treatment group, a significantly lower total consumption of morphine (P < 0.05), associated with a shorter duration of patient-controlled analgesia (P < 0.02) and a decreased mean number of unsuccessful demands (P < 0.001) were recorded. Intercostal blockade with bupivacaine-phenol supplements intravenous patient-controlled analgesia for post-cholecystectomy pain relief.

Monitoring the onset of neuromuscular blockade with double burst stimulation (DBS).

The present study was undertaken to evaluate the suitability of the DBS mode in the determination of the proper time to perform tracheal intubation following cisatracurium muscle relaxation. The DBS3.3 pattern was administered to the ulnar nerve at the wrist in 45 patients paralyzed with cisatracurium 0.15 mg.kg-1 and tracheal intubation was attempted immediately after the disappearance of both palpable contractions of the adductor pollicis. Intubation conditions were assessed with a standard four-graded scoring system and the onset time of the relaxant was determined. Forty-two patients (93%) exhibited acceptable intubation conditions as soon as both responses to DBS were absent and the estimated apparent onset time, according to the stimulation mode applied, was 114.68 +/- 13.2 sec. Our data suggest that disappearance of both palpable responses to DBS3.3 may be used as an accurate predictor of acceptable intubation conditions, following nondepolarizing relaxants such as cisatracurium.

Hypoxic pretreatment protects against neuronal damage of the rat hippocampus induced by severe hypoxia.

The present study investigates whether under conditions of successive hypoxic exposures pretreatment with mild (15% O(2)) or moderate (10% O(2)) hypoxia, protects hippocampal neurones against damage induced by severe (3% O(2)) hypoxia. The ultrastructural findings were also correlated with regional superoxide dismutase (SOD) activity changes. In unpretreated rats severe hypoxia induced ultrastructural changes consistent with the aspects of delayed neuronal death (DND). However, in preexposed animals hippocampal damage was attenuated in an inversely proportional way with the severity of the hypoxic pretreatment. The ultrastructural hypoxic tolerance findings were also closely related to increased regional SOD activity levels. Thus the activation of the endogenous antioxidant defense by hypoxic preconditioning, protects against hippocampal damage induced by severe hypoxia. The eventual contribution of increased endogenous adenosine and/or reduced excitotoxicity to induce hypoxic tolerance is discussed.