Selective effect of fentanyl on group III and IV somatosympathetic reflexes.

The effect of fentanyl on sympathetic reflexes evoked by supramaximal electrical stimulation of the radial nerve, and the subsequent reversal of its effects by naloxone, have been observed in 10 dogs anaesthetized with alpha-chloralose, paralysed with suxamethonium and artificially ventilated. During infusions of 5 micrograms kg-1 min-1 the late, long-latency, sympathetic response evoked by unmyelinated fibres was abolished at a mean dose of 27 micrograms kg-1 (SD 12.6 micrograms kg-1) after which the early, short-latency response evoked by small myelinated fibres was eliminated at a mean dose of 90.3 micrograms kg-1 (SD 54.6 micrograms kg-1) so that there was no longer any response to stimulation of the radial nerve. During a subsequent infusion of naloxone (200 micrograms min-1) the late response returned to control values at a mean dose of 0.5 mg and subsequently the early response reappeared to return to control values at a total dose of 1.6 mg. In 2 preparations phrenic nerve activity was abolished after 6.1 and 17.4 micrograms kg-1 of fentanyl and returned immediately before the late response, during the infusion of naloxone. In 2 preparations, induced tolerance occurred so that the early response could not be eliminated.

Augmentation of bupivacaine analgesia in labor by epidural morphine.

The analgesic properties and motor effect of epidural 0.25% bupivacaine (8 mL) were compared with those of epidural morphine (2 mg in 10 mL saline) followed by 8 mL of 0.25% bupivacaine. The study was performed on two groups of parturients (30 in each group) in active labor. Pain relief in the morphine-bupivacaine group lasted for a mean of 131.1 minutes (SD +/- 49.8) as opposed to the plain bupivacaine group -57 minutes (SD +/- 15.28). Satisfaction from analgesia in the morphine-bupivacaine group was higher as well. Motor involvement was not seen in either group. Perineal pain relief in the postpartum period lasted for a mean of 16 hours and 40 minutes in the morphine-bupivacaine group. It was concluded that the concomitant use of epidural morphine augmented the analgesic effect of 0.25% bupivacaine without motor effect.

Epidural analgesia for planned vaginal delivery following previous cesarean section.

The effect of lumbar epidural on the course of labor, delivery, and outcome was studied in 115 parturients with a previous cesarean section who were given a trial of vaginal delivery. One hundred three women were multiparous and 12 were grandmultiparous. Uterine contractions and fetal heart rate (FHR) were monitored continuously in all patients. Epidural block was performed using 8 mL of 0.35% bupivacaine without adrenaline. Supplemental doses were administered through an indwelling catheter. At the beginning of the second stage, 10 mL of 0.25% bupivacaine was added in the sitting position. Forty-eight women delivered spontaneously and 54 had an assisted second stage. Thirteen women delivered by a repeat low segmental cesarean section; dehiscence was observed in only one woman. Fetal outcome was satisfactory and similar to that of the authors' general parturient population.

RO 15-1788 produces naloxone-reversible analgesia in the rat.

Intraperitoneal and intracerebroventricular administration of the benzodiazepine antagonist RO 15-1788 produced analgesia to both thermal and mechanical pain. This effect was reversed by pretreatment with the opioid antagonist naloxone but was unaffected by pretreatment with the benzodiazepine agonist midazolam. Furthermore, administration of the benzodiazepine antagonist RO 15-3505 was without analgesic effect. It is, therefore, proposed that the intrinsic action induced by RO 15-1788 is exerted via the indirect activation of endogenous opioid systems and that the observed effect is not due to the action of the antagonist on the benzodiazepine receptor.

The assessment of radiating low back pain by thermal sensory testing.

Low back pain radiating into the legs is a common pain syndrome. However, neurological examination, imaging and electromyographic studies are of limited value for prognosis or therapy. The origin of the pain remains unknown. The aim was to evaluate the potential of thermal sensory testing to serve as a diagnostic tool in 24 patients who had low back pain radiating down the S1 dermatome, compared with 26 pain-free controls. The method of limits was used to detect the thresholds of warm sensation, cold sensation, warm pain and cold pain at the L4, L5 and S1 dermatomes of the symptomatic and the non-symptomatic legs. Thresholds on the asymptomatic leg were similar to values obtained in controls. We found a significantly higher threshold for cold sensation in the S1 dermatome of the symptomatic leg of the patients compared with the controls (p< 0.005). In addition, patients who had abnormal neurological examination (50%) had higher thresholds for cold sensation or cold pain in the three dermatomes tested at the symptomatic leg compared with the non-symptomatic leg. No differences in the thresholds of warm sensation or warm pain were detected. We propose that these findings indicate selective damage to the Adelta fibres which are involved in transmission of cold sensation and pain, presumably by root compression. We found no evidence of involvement of C fibres, which transmit warm sensation and pain. Thermal testing should be considered among the testing modalities that are capable of demonstrating objective findings in patients with radiating low back pain.

Flumazenil potentiation of postoperative morphine analgesia.

OBJECTIVE: The goal of this study was to test the effect of concomitant administration of flumazenil (FL) and morphine (MO) on immediate postoperative analgesia and the MO requirement to control pain in human beings. DESIGN AND INTERVENTIONS: Thirty-six patients undergoing inguinal hernioplasty under lidocaine epidural anesthesia were enrolled in this double-blind, randomized, controlled study. On the first complaint of pain, either MO (2 mg) only or MO (2 mg) plus FL (0.2 mg) was administered. Additional doses of the same medications administered via a patient-controlled analgesia device with a 10-minute lockout period were available thereafter. The study continued for 2 hours after the loading doses of the medications were administered, with an additional 2-hour period of observation. RESULTS: Thirty-two patients completed the study. Both groups reached a similar satisfactory equianalgesic state (2 in a 0-10 visual analogue scale). The MO plus FL group consumed 9.5 +/- 1.1 mg of MO versus 14.1 +/- 1.1 mg of MO (p < 0.001) in the MO only group. The MO plus FL patients were subjectively (visual analogue scale) more comfortable and less sedated than the MO patients. "Fine" coordination (using an electronic maze) and "coarse" coordination (measured by transferring a pen from one hand to another as rapidly as possible with both arms placed inside an 80-cm metal frame) in the MO group were worse than in the MO plus FL group. End-tidal CO2 increased and blood pressure decreased in the MO group. There were few and insignificant side effects in the MO group. None of these patients required an MO antagonist, and recovery was prolonged in none. CONCLUSIONS: Flumazenil afforded lower MO consumption during the immediate postoperative period. Cognitive, hemodynamic, and respiratory functions were better after MO plus FL than after MO alone.

Postoperative injuries of upper limb nerves.

Three cases of different types of nerve injuries following orthopedic and chest surgery are described. Recovery from these nerve injuries was prolonged and incomplete. By constant awareness of potential nerve damage during operation, it is possible to prevent such injuries.

Postherpetic neuralgia: clinical experience with a conservative treatment.

Ninety-seven consecutive cases of postherpetic neuralgia (PHN) were retrospectively reviewed. Patients comprised 49 women and 48 men with a mean age of 71.6 years. The most common painful locations were the chest and upper back (34%), abdomen and lower back (25.2%), and face (20.2%). Burning pain was the most common type of pain (61.3%). Lancinating pain was reported by 40% and throbbing pain by 22.6%. Treatments included drugs (mainly tricyclic antidepressant, anticonvulsant, and neuroleptic drugs), transcutaneous electrical nerve stimulation (TENS), and dry needling of muscles in the affected dermatomes. Positive response to treatment occurred in 18.5% of the patients after one visit. In 9.3% of the patients, the pain still could not be controlled after 10 visits of 2-week intervals. TENS proved to be effective in patients whose skin sensation was preserved. It was concluded that in most PHN cases, pain can be effectively controlled by conservative noninvasive therapy.

Epidural morphine pretreatment for postepisiotomy pain.

OBJECTIVE/DESIGN: A randomized double-blind controlled study was conducted on two groups of 45 parturients to evaluate the importance of the timing of epidural morphine administration for the relief of postepisiotomy pain. Both groups had preemptive analgesia by continuous lumbar epidural bupivacaine blockade. Upon completion of the episiotomy repair and before the onset of pain, the patients received epidural injections of 3 ml saline with or without 2 mg morphine in groups A and B respectively. When pain appeared, group A patients received an epidural injection of 3 ml saline while group B patients received 2 mg morphine in 3 ml saline. Postepisiotomy pain level was evaluated by a visual analogue scale. RESULTS: The incidence of pain in group B women following epidural morphine administration was 68.6%. This was significantly higher than that of group A at 15.6% (p < 0.01). Furthermore, group B showed that the rate of effective pain relief after 2 mg epidural morphine significantly decreases as the level of pain intensity rises (p < 0.01). CONCLUSION: Epidural morphine for postepisiotomy pain is much more effective if administered before the onset of pain.

Early clinical experience in reversing benzodiazepine sedation with flumazenil after short procedures.

Flumazenil (Flu) (Ro 15-1788, Anexate) is a newly synthetized specific benzodiazepine (BZD) antagonist which was recently introduced for clinical study. The drug was intravenously injected, in titrated doses, to patients undergoing diagnostic or therapeutic procedures in order to reverse the sedative effects of BZDs. A total of 63 patients undergoing hand surgery under i.v. regional block, lower abdominal surgery under epidural anesthesia, cardiac catheterization, intracardiac catheter ablation, cardioversion, gastroscopy and bronchoscopy were studied. Flu in a dose ranging from 0.1 to 0.42 mg effectively reversed BZD-induced sedation in all patients 1-2 min following i.v. injection. Patients were fully awake and oriented yet calm and in good mood. Flu was well tolerated even in the high risk cardiac patients, with no significant changes in vital signs nor any sign of local irritation at the site of Flu injection. No significant resedation was observed. Thus Flu was very useful in reversing BZD-induced sedation or unconsciousness in a variety of clinical situations.

The use of flumazenil in the treatment of 34 intoxicated patients.

The efficacy and safety of the newly available benzodiazepine (BDZ) antagonist flumazenil (Ro 15-1788, Anexate) was prospectively evaluated in the treatment of 34 intoxicated patients. Twenty-three patients had attempted suicide with various drugs, and 11 suffered iatrogenic BDZ overdose. Following 0.2 mg i.v. flumazenil (Flu) injection, 22 patients intoxicated mainly with BDZ (11 iatrogenic and 11 intentional) regained full consciousness within two minutes, enabling even extubation of two. Eight patients required repeated boluses or continuous infusion of Flu to maintain alertness. Five patients with mixed drug intoxication awakened only briefly and relapsed into unconsciousness. In spite of Flu doses of up to 20 mg, no effect on consciousness was observed in 7 patients, intoxicated mainly with non-BDZ drugs. No significant side effects were noted attributable to Flu which has proved to be a safe and effective drug. It may be employed to achieve complete reversal of pure BDZ overdose, or for 'unmasking' the relative action of BDZ in mixed drug overdose. The danger of complications from drug overdose may thus be lessened, obviating the need for invasive interventions such as mechanical ventilation and invasive hemodynamic monitoring, at the same time decreasing risk and expense.

Outpatient versus inpatient cervical cerclage.

The outcomes in 125 cases of elective, outpatient cerclage placement were compared to those in 101 cases of elective, inpatient cerclage placement with the same technique at the same institution. There was no difference between the two groups in the rates of early and late complications or in the effect of the procedure on the duration of gestation. As expected, a statistically significantly shorter hospital stay occurred in the outpatient group. The outpatient procedure is as effective as the inpatient one, with no increased risk of early and late complications, and offers patients a shorter absence from home, thus possibly decreasing their anxiety, and considerable financial savings.

Pain and quality of life.

This paper deals with the impact of pain on quality of life (QOL). Two major factors have contributed to the enhanced importance of QOL in recent years: the increasing frequency of pain and the resources devoted to its treatment, and the growing theoretical insight that pain affects the person as a whole. QOL is defined as the person's evaluation of his or her well-being and functioning in different life domains. It is a subjective, phenomenological, multidimensional, dynamic, evaluative, and yet quantifiable, construct. Commonly used scales for its assessment (eg, WHOQOL, SF-36) are described. Studies show that pain affects most domains of QOL, primarily physical and emotional functioning. The effect depends on the extent, duration, acuteness, intensity, affectivity, and meaning of the pain as well as on the underlying disease and the individual's characteristics. QOL is sensitive also to the treatment of pain and treatment modalities, as shown particularly by studies on cancer pain. Pain reduction is not always attended by the expected improvement in QOL. Pain is not synonymous with poor QOL and constitutes only one important factor determining QOL. The main conclusions are that treatment of pain should be multidisciplinary, considering the impact of pain and the treatment on QOL and targetting also improvement of the affected domains of QOL.

[The benefit of combining spinal morphine and intravenous buprenorphine for perioperative pain].

Concurrent administration of opioids with different affinity produces synergistic antinociceptive effect in rats. We tested the perioperative antinociceptive effects of the simultaneous double blind administration of morphine, a pure agonist and buprenorphine, a partial agonist, in 30 patients undergoing hysterectomy under general anesthesia. Pre- and post-operatively regimens consisted of random patient assignment to intrathecal 0.3 mg morphine plus intravenous saline (group 1), intravenous 0.09 mg buprenorphine plus intrathecal saline (group 2) or intrathecal morphine 0.3 mg plus intravenous buprenorphine 0.09 mg (group 3). Postoperative pain relief for group 3 consisted of supplementation of intravenous buprenorphine plus intrathecal saline. The immediate postoperative pain, sedation and anxiety levels (by numerical or categorical scores) were similar among all groups. The 12-hour pain and sedation scores were significantly (P < 0.05) lower in group 3 than in the other two groups. Buprenorphine-induced analgesia in group 3 lasted significantly (P < 0.05) longer than in group 2. Side effects in groups 2 and 3 were by 44% and 42% fewer than in group 1, respectively, with no withdrawal symptoms. Thus, concomitant administration of intrathecal morphine and low dose intravenous buprenorphine produces better and longer pain relief than intravenous buprenorphine alone in women after hysterectomy.

Electromyographic signal-activated functional electrical stimulation of abdominal muscles: the effect on pulmonary function in patients with tetraplegia.

BACKGROUND: Paralysis of abdominal muscles is the main cause of respiratory dysfunctions in patients with lower cervical spinal cord lesion. Activation of the abdominal muscles using functional electrical stimulation (FES) improved respiratory function in these patients. But application of FES frequently requires a caregiver, and it may not be well synchronized with the patient's respiratory activity. OBJECTIVE: To perform preliminary examination of electromyographic (EMG)-activated FES for caregiver-independent and synchronized cough and expiration induction in tetraplegia. DESIGN: Self-controlled study. SETTING: Loewenstein Rehabilitation Center, Raanana, Israel. SUBJECTS: A total of 10 male patients with complete or almost complete tetraplegia. MAIN OUTCOME MEASURES: Peak expiratory flow (PEF), forced vital capacity (FVC), and maximal voluntary ventilation (MVV). METHODS: The outcome measures were examined with the abdominal muscles unassisted or assisted by various methods. These included manual assistance or application of FES, activated by a caregiver, by the patient, or by EMG signals elicited from the patient's muscle. RESULTS: Manual assistance improved the mean PEF value by 36.7% (P<0.01) and the mean FVC value by 15.4% (P=0.01). FES did not significantly change most measurements, and patient-activated FES even reduced PEF (P<0.05). But following EMG-activated FES PEF and FVC values were higher than those following patient-activated FES (P<0.05 for PEF; P<0.01 for FVC), and their mean values were higher by 15.8 and 18.9%, respectively. CONCLUSIONS: Abdominal FES failed to improve respiratory function in this study, but applying FES to abdominal muscles by EMG from the patient's muscle may promote caregiver-free respiration and coughing in persons with cervical SCL.