The effect of 0.5% ropivacaine on epidural blood flow

Twenty patients scheduled for elective abdominal surgery received epidural analgesia with 20 ml 0.5% ropivacaine or 0.5% bupivacaine. Epidural blood flow was measured by an epidural 133Xe clearance technique on the day before surgery (no local anaesthetic) and again 1 h before surgery, 30 min after injection of the local anaesthetic during continuous infusion (8 ml/h). Median initial blood flow was 5.0 ml/min and 6.0 ml/min per 100 g tissue in patients receiving ropivacaine and bupivacaine, respectively. After epidural bupivacaine, blood flow increased in 8 of 10 patients to 6.9 ml/min per 100 g tissue (P less than 0.05) in contrast to a decrease in 9 of 10 patients to 3.3 ml/min per 100 g tissue after ropivacaine (P less than 0.05), (P less than 0.01 between groups). The median level of sensory analgesia was T3.5 and T4.5 in the ropivacaine and bupivacaine group, respectively (P greater than 0.05). The demonstrated vasoconstrictor effect of epidural ropivacaine may influence the duration of its local anaesthetic effect.

Prevention of postoperative pain by balanced analgesia

Fourteen patients undergoing colorectal surgery received an intraoperative afferent neural block with combined intrathecal and extradural local anaesthetics plus a balanced postoperative low-dose regimen of extradural bupivacaine 10 mg h-1-morphine 0.2 mg h-1 and systemic piroxicam 20 mg/24 h. Postoperative pain, assessed repeatedly during the initial 48 h, was prevented during rest, mobilization from the supine to the sitting position and during walking, in all but one patient; slight pain was observed intermittently during coughing in four patients.

[Post-dural puncture headache]

Post dural puncture headache is one of the major complications of spinal anaesthesia. In order to establish this diagnosis, the headache must be dependent on the position of the patient. The symptoms are probably due to leakage of cerebro-spinal fluid from the subarachnoid space to the epidural space which results in intracranial hypotension and tension of the nociceptive intracranial structures. The incidence is highest in young patients and the complication is observed more frequently in women than in men. In all age groups, the frequency and severity of the condition depend upon the calibre of the puncture needle and, for this reason, the finest possible needle should be employed. The only well proved prophylactic and curative treatment consists of establishing an epidural blood-patch. This procedure should be considered as the primary method of treatment in patients in whom post dural puncture headache contributes to prolongation of the period of convalescence.

Effect of thoracic epidural bupivacaine 0.75% on somatosensory evoked potentials after dermatomal stimulation

The effect of thoracic epidural bupivacaine 0.75%, 9 ml, on early (less than 500 ms) somatosensory evoked potentials (SEPs) during electrical stimulation of the T10 and L1 dermatomes was examined in ten patients. Spread of analgesia (pinprick) was T3.7 +/- 0.5 to L2.5 +/- 1 (mean +/- SEM). Peak-to-peak amplitudes of the T10 SEPs were reduced (p less than 0.05) while an insignificant reduction was found in L1 stimulated potentials. SEPs were abolished in four and two patients at the T10 and L1 levels, respectively. The latency of the early SEP components (0, P1-3, N1-3) increased (p less than 0.05) at T10 but was not significant at L1 except for N2 and N3. Sensory threshold increased significantly in both stimulation areas during blockade. In conclusion, thoracic epidural administration of 9 ml of bupivacaine 0.75% does not provide total afferent somatic blockade despite sensory analgesia to pinprick.

Spinal anaesthesia in young patients using a 29-gauge needle: technical considerations and an evaluation of postoperative complaints compared with general anaesthesia

One hundred patients aged 18-49 yr, undergoing elective arthroscopy of the knee joint, were allocated randomly to either spinal anaesthesia using a 29-gauge spinal needle or general anaesthesia. Dural puncture was considered difficult in 18% of the patients receiving spinal anaesthesia. In three patients (6%) it was necessary to supplement the spinal anaesthetic with general anaesthesia. Spinal and general anaesthesia were otherwise uneventful in all patients. The incidence of postoperative headache was similar in the two groups. One patient developed post dural puncture headache following spinal anaesthesia. This headache was of short duration and disappeared without treatment. Spinal anaesthesia caused more backache than general anaesthesia, otherwise the frequency of postoperative complaints was the same or lower. Ninety-six percent of the patients receiving spinal anaesthesia would prefer the same anaesthetic for a similar procedure in the future.

[Clinical aspects of spinal anesthesia administered using 0.5% isobar bupivacaine (Maracine) at the L2/L3 or L4/L5 level]

The effect of employing different interspaces for lumbar puncture during spinal anaesthesia was evaluated in 40 patients receiving 4 ml of 0.5% plain bupivacaine at level L2/L3 or L4/L5. No differences were observed in onset, spread or duration of analgesia. Furthermore, we found that only 80% of the patients, independently of the interspace used, had a cephalad spread to T8 and conclude that spinal anaesthesia using plain bupivacaine is not ideal for supraumbilical surgery.

Continuous blockade of the lumbar plexus after knee surgery--postoperative analgesia and bupivacaine plasma concentrations. A controlled clinical trial

In a double blind, randomised, controlled investigation the analgesic effect of a continuous block of the lumbar plexus with bupivacaine compared with sodium chloride was examined in 20 patients with postoperative pain after knee-joint surgery. The infusion was given through a catheter inserted in the neurovascular fascial sheath of the femoral nerve, according to the three-in-one block technique. The patients treated with bupivacaine had significantly lower pain scores and a significantly lower demand for morphine. Side effects related to the catheters or the infusions of bupivacaine were not observed.

Perineuronal morphine: a comparison with epidural morphine

In a double-blind, randomised controlled cross-over study the effects of perineuronal (perifemoral) injections of morphine were compared with epidural injections with the same amount of morphine in patients after knee surgery. Better pain scores were achieved during treatment with epidural morphine. We have not been able to confirm the hypothesis of neuro-axonal transport of morphine from the periphery to the spinal cord.

Patient-controlled analgesia: a controlled trial

Thirty-six patients undergoing lower abdominal surgery were included in a prospective randomized controlled study to compare the effects of patient-controlled analgesia (PCA) and a standard intramuscular/intravenous treatment (conventional analgesia, CA) of postoperative pain. Morphine was used in both groups. There were no significant differences between the two analgesic regimens in respect of linear analogue pain scores, verbal pain-relief scores, amount of morphine used or side-effects. No treatment-induced alterations in vital values were experienced.

The isolation and characterization of a root lectin from soybean (Glycine max (L), cultivar Chippewa)

A lectin has been isolated from the roots of 5-day soybean (Glycine max (L) cultivar Chippewa) seedlings, and its properties have been compared to those of the soybean seed lectin. The sugar-binding activities of the two lectins, both in terms of specific hemagglutinating activity and sugar specificity, are indistinguishable. Molecular properties of the two lectins, measured as relative molecular weights, isoelectric and electrophoretic patterns, amino acid compositions, immunochemical cross-reactivity, and chromatographic behavior on Sepharose-concanavalin A adsorbents suggest that the seed and the root lectin are very similar but not identical. On the basis of these comparisons, we conclude that models regarding biological functions of soybean lectin derived from studies using the seed lectin can be extended to include the root lectin in this cultivar. Studies on the distribution of the lectin in the root tissue suggest that it is associated with the outer surface of the root and is concentrated in the segments of the root at which hair and early secondary roots are observed. Since this is the region at which Rhizobium binding occurs and at which nodulation probably is initiated, all the reported observations on the root lectin are consistent with its proposed role in the specific interaction of the developing soybean with its symbiont.