Postoperative pain treated by intravenous L-tryptophan: a double-blind study versus placebo in cholecystectomized patients.

The effectiveness of intravenous administration (i.v.) of L-tryptophan, which is the precursor of cerebral serotonin, was verified in the treatment of postoperative pain. The study was carried out on 45 female patients, aged between 34 and 61 years, undergoing cholecystectomy who were randomly divided into three groups. Group 1 (age: 50.33 +/- 8.64 years) received 100 ml of 5% mannitol solution i.v.; group 2 (age: 49.80 +/- 11.11 years) 100 ml of a mannitol solution containing 7.5 mg/kg L-tryptophan; and group 3 (age: 53.46 +/- 9.60 years) 100 ml of a mannitol solution containing 15 mg/kg L-tryptophan. Vital capacity (preoperative VC) was measured before surgery. Anesthesia used was isoflurane. Narcotics or neuroleptics were not used. Pain was assessed before treatment (T-0 min), at the end of administration (T-30) and at T-60, 120, 180, 240, 300 and 360 min by the following variables: respiratory rate (RR), heart rate (HR), mean arterial pressure (MAP), Scott-Huskisson test (VAS), pain vital capacity (PVC), analgesic vital capacity (AVC), and respiratory restoration factor (RRF) calculated from Bromage's formula (RRF = (AVC - PVC/preoperative VC - PVC) X 100). As regards variables RR, HR, MAP and VAS, differences between the values from T-30 to T-360 and the value at T-0 were calculated. Means and S.E.M. were calculated on the obtained values and on RRF values for each group. The significance of the differences between groups was calculated using Student's t test and Bonferroni's test. Results show a significant decrease of pain in groups 2 and 3 treated with L-tryptophan, in comparison with group 1 (controls). No significant difference was observed between the treated groups, although more lasting pain relief was observed in group 3 in comparison with group 2. Intravenous L-tryptophan showed its effectiveness in the treatment of postoperative pain even when used alone. Its use may be considered for patients with renal failure, in order to strengthen pharmacological analgesia or to prevent postoperative pain by its intraoperative administration.

Diode laser in cervical myofascial pain: a double-blind study versus placebo.

We present a double-blind trial in which a pulsed infrared beam was compared with a placebo in the treatment of myofascial pain in the cervical region. The patients were submitted to 12 sessions on alternate days to a total energy dose of 5 J each. At each session, the four most painful muscular trigger points and five bilateral homometameric acupuncture points were irradiated. Those in the placebo group submitted to the same number of sessions following an identical procedure, the only difference being that the laser apparatus was nonoperational. Pain was monitored using the Italian version of the McGill pain questionnaire and the Scott-Huskisson visual analogue scale. The results show a pain attenuation in the treated group and a statistically significant difference between the two groups of patients, both at the end of therapy and at the 3-month follow-up examination.

The effect of benzodiazepines administration on auricular symptomatological evidence.

The aim of this study is to verify the response of auricular skin to interoceptive stimuli in two groups of patients suffering from a gastroenteral pathology. Patients were submitted to a complete examination of auricle, in order to detect morphological alterations and painful points, and to a diagnostic digestive endoscopy. A group of patients took benzodiazepines at the moment of auricular examination; the second group did not take any drug. Results show that there is a significantly lower number of auricular painful points in the patients taking benzodiazepines in comparison with the patients who did not take such drug. In the patients treated with benzodiazepines the auricular diagnosis of painful points does not seem to be reliable.

[Spinal anesthesia in cesarean section: 1% versus 0.5% hyperbaric bupivacaine]. / Anestesia spinale nel taglio cesareo: confronto tra bupivacaina iperbarica all'1% ed allo 0,5%.

AIM: To compare the quality of anesthesia produced by the intrathecal administration of equivalent doses of 0.5% and 1% hyperbaric bupivacaine in patients undergoing cesarian section. EXPERIMENTAL DESIGN: A prospective, comparative and randomised clinical study. SETTING: Anesthesia Unit-Non-university civil hospital. PATIENTS: 50 patients undergoing elective or emergency cesarian section randomly assigned to two groups of 25 patients each. SURGERY: After prehydration, subarachnoid access was achieved through space L2-L3 or L3-L4 using a 24G Sprotte's needle with patients in right hand lateral decubitus. Patients in group A were injected with 1.25 ml of 1% hyperbaric bupivacaine and those in group B with 2.5 ml of 0.5% hyperbaric bupivacaine (12.5 mg). Patients were positioned immediately in partial decubitus on their left hand sides and ephedrine infusion, or if required i.v. bolus, was commenced to counter hypotension (SAP < 80% basal). MEASUREMENTS: ECG, pulse measurement, arterial pressure with non-invasive method, metameric level of analgesia (pin prick), motor block of lower limbs (Bromage's scale), time lapsed between induction of anesthesia and extraction of neonate, Apgar score, quantity of ephedrine used, duration of surgery, respiratory complications, insufficient analgesia, resolution of motor block, any postspinal cephalea. STATISTICAL ANALYSIS: Variance analysis, Student's t-test, chi 2. RESULTS: Both solutions guaranteed satisfactory intraoperative analgesia in 96% of cases. No statistically significant differences were noted between the two groups relating to the maximum duration of analgesia, the extent of motor block, induction times and regression, incidence of complications. CONCLUSIONS: No important difference was observed in the quality of the anesthesia obtained using the intrathecal administration of equivalent doses of 1% and 0.5% solutions of hyperbaric bupivacaine in patients undergoing cesarian section. In view of the possible relationship between the neurotoxicity of local anesthetics and the concentration of the solution used for spinal anesthesia, it is to be hoped that less concentrated solutions of hyperbaric bupivacaine will be introduced in Italy compared to the 1% solution currently available.