The nature and management of labor pain: part II. Pharmacologic pain relief.

A group of family physicians, obstetricians, midwives, obstetric anesthesiologists, and childbirth educators attended an evidence-based symposium in 2001 on the nature and management of labor pain and discussed a series of systematic reviews that focused on methods of labor pain management. Parenteral opioids provide modest pain relief in labor, and little evidence supports the use of one agent over another. Epidural analgesia is used during labor in most large U.S. hospitals, and its use is rapidly increasing in small hospitals. Although epidural analgesia is the most effective form of pain relief, its use is associated with a longer labor, an increased incidence of maternal fever, and increased rates of operative vaginal delivery. The effect of epidural analgesia on rates of cesarean delivery is controversial. Nitrous oxide provides a modest analgesic effect, but it is used less often in the United States than in other developed nations. Paracervical block provides effective analgesia in the first stage of labor, but its use is limited by postblock bradycardia. Research is needed regarding which pain-relief options women would choose if they were offered a range of choices beyond epidural analgesia or parenteral opioids.

Spinal cord stimulation--a long-term evaluation in patients with chronic pain.

Spinal cord stimulation (SCS) is an established treatment modality for chronic pain, angina pectoris, and peripheral vascular disease. This study evaluates experience with SCS over a 13-year period with emphasis on surgical complications, revisions and pain relief. It took the form of a retrospective study of medical/surgical records coupled with a postal/telephone questionnaire. The subjects consisted of seventy patients, aged from 21 to 76 years (mean 47; median 46), with severe, chronic pain refractory to conventional treatment, who underwent SCS implantation between 1984 and 1997. It investigated surgical revisions, complications and pain relief. There were 72 surgical revisions comprising electrode replacement/repositioning (32), generator replacement (22), cable failure (6) and implant removal (12). Half the devices were revised within 3 years (95% confidence interval: 2-5 years) of implantation. Six (8.6%) implants became infected. Sixty per cent of patients reported substantial relief of pain. This study shows that the majority of patients undergoing SCS derive significant benefit in terms of pain relief, but commonly require surgical revisions due to both technical and biological factors. These devices require systematic evaluation to determine optimal usage, clinical effectiveness and cost-benefit analysis.

Pain and the ethics of pain management.

KIE: After clarifying the concepts of "pain", "suffering", "pain of body", and "pain of soul", the author presents a humanistic ethic of pain management based on the premise that the patient has a strong "prima facie" right to freedom from unnecessary pain. This premise imposes two moral obligations upon medical professionals: (1) the duty not to inflict unnecessary pain and suffering upon the patient, and (2) the duty to do whatever is possible to alleviate pain and suffering. Both the questions of informed consent to treatment of pain and the right to refuse pain relief are addressed.

Single-needle celiac plexus block: is needle tip position critical in patients with no regional anatomic distortions?

BACKGROUND: The "single-needle" celiac plexus block is becoming a popular technique. Despite different approaches and methods used to place the needle, the success of the block depends on adequate spread of the injectate in the celiac area. In the present retrospective study, the influence of needle tip position in relation to the celiac artery on injectate spread was evaluated. METHODS: Among 138 cancer patients subjected, via an anterior approach, to computed tomography (CT)-guided single-needle neurolytic celiac plexus block, a radiologist, blinded to the aim of the study, retrospectively selected 53 cases with normal anatomy of the celiac area as judged by CT. The decision was based on images obtained before the block. Patients were then classified into either group A (29 patients), in whom the needle tip was caudad to the celiac artery, and group B (24 patients), in whom it was cephalad. To evaluate CT patterns of neurolytic (mixed with contrast) spread, the celiac area was divided on the frontal plane into four quadrants: upper right and left and lower right and left, as related to the celiac artery. Patient assessments by visual analog scale were reviewed to evaluate the degree of pain relief. pain relief 30 days after block was judged as long-lasting. The patterns of contrast spread in relation to the needle position and pain relief according to the number of quadrants with contrast were analyzed. RESULTS: The percentage of cases with four quadrants with contrast was higher when the needle tip was cephalad (58%, group B) than when it was caudad (14%, group A) to the celiac artery (P < 0.01). The percentage of patients with four and three quadrants with contrast was also higher in group B at 79% than in group A at 38% (P < 0.01). A significant difference in long-lasting pain relief was observed between patients with four quadrants with contrast (18 of 18, 100%; 95% confidence interval [CI], 81-100%) and patients with three quadrants with contrast (5 of 12, 42%; 95% CI, 15-72%) (P < 0.01). No patients showing two or one quadrant with contrast had long-lasting pain relief. CONCLUSIONS: These findings suggest that, when the celiac area is free from anatomic distortions, and the single-needle neurolytic celiac plexus block technique is used, the needle tip should be positioned cephalad to the celiac artery to achieve a wider neurolytic spread. It also appears that only a complete (four quadrants) neurolytic spread in the celiac area can guarantee long-lasting analgesia.

Lumbar epidural blockade for management of pain in interstitial cystitis.

Thirteen patients with interstitial cystitis (IC), whose predominant symptom was pelvic or urethral pain, were treated with a series of lumbar epidural local anaesthetic blocks over an 18-month period. Response was evaluated by interview and with voiding diaries and visual analogue scales (VAS) for pain. Of the 55 injections given, immediate pain relief (lasting longer than 24 h) was obtained from 41 (75%). The duration of subsequent pain relief varied considerably, ranging from 2 to 75 days (mean 15.1). pain relief was accompanied by significant improvement in sleep habit and quality of life. A good correlation was noted between verbally expressed pain and the recorded VAS pain scores. Urinary frequency and average voided volumes were unaffected by treatment. Two patients failed to obtain any relief. Apart from minor transient backache at the injection site, there were no complications from the procedure. Lumbar sympathetic epidural blockade is an excellent means of providing pain relief in interstitial cystitis.

Lumbar facet joint synovial cyst: percutaneous treatment with steroid injections and distention--clinical and imaging follow-up in 12 patients.

PURPOSE: To determine the imaging characteristics of lumbar facet joint synovial cysts after percutaneous treatment with steroid injections and distention of the cyst and to correlate these findings with the clinical outcome. MATERIALS AND METHODS: Clinical outcome and imaging findings were retrospectively studied in 12 patients (four men, eight women) aged 45-79 years (mean, 60 years) with a symptomatic lumbar facet joint synovial cyst treated with percutaneous steroid injections. At varying times after the procedure, patients were contacted for clinical follow-up, and repeat imaging was performed to verify the status of the cyst. RESULTS: Excellent pain relief was achieved in nine (75%) of 12 patients. At follow-up imaging, the cyst completely regressed in six (67%) of these nine patients, partially regressed in two (22%) patients, and was unchanged in one (11%) patient. One (8%) of the 12 patients had transient pain relief, with recurrence of symptoms at short intervals after each of three injections. No pain relief was achieved in two (17%) of 12 patients. CONCLUSION: Image-guided percutaneous steroid injections are often effective in the treatment of lumbar facet joint synovial cysts and may result in complete regression of the cyst.

Cervical epidural morphine and buprenorphine for postoperative pain relief after thoracic surgery--a comparative study in the same patients

The effects of cervical epidural morphine and buprenorphine on postoperative pain were studied in 12 patients who received thoracic surgery twice. The patients who had received morphine 3 mg on the first operation were given buprenorphine 0.15 mg on the second operation, and the others received them vice versa. Morphine or buprenorphine was administered with 6 ml of 0.25% bupivacaine before skin incision. The duration of pain relief with morphine was longer (21.5 +/- 4.0 h) than with buprenorphine (13.9 +/- 7.8 h). The result of the questionnaires to the patients after operation shows that 10 patients (84%) were satisfied with morphine whereas only 6 patients (50%) were satisfied with buprenorphine. Seven patients preferred morphine to buprenorphine for postoperative analgesia, and the rest of the patients stated that analgesic effects were similar between the two. It seems that epidural morphine 3 mg may give more excellent postoperative pain relief after the thoracic surgery than epidural buprenorphine 0.15 mg.

Electroanalgesia by transcutaneous stimulation (TNS). Response to the naloxone test

The authors, after a review of the literature about TNS, suggest the comparison between three different TNS techniques from two points of view: A) pain relief estimate; B) Response to Naloxone Test. To this purpose a impulse generator delivered a biphasic square-wave stimulus with duration of 0.40 msec and amplitude (peak to peak) to 130 mVolt, was used. TNS techniques used are so characterized 1) Frequency 80 Hz; Duration 30'; 2) Frequency 80 Hz; Duration over 120'; 3) Frequency 2/4 Hz; Duration over 120'. Although the techniques used for Group (1) provided the best numerical result in the evaluation of the pain relief, endorphine activity cannot be maintained owing to Naloxone Test negativity. pain relief of (2) and (3) Group was statistically significant although not numerically at the same level of (1) Group. In the laters, on the contrary, positivity of Naloxone Test seems to hint at the activation of endorphine. This fact suggest to the authors hypothesis in the purpose to spot TNS site of action.

Epidural morphine for postoperative pain relief: a dose-response curve.

Different doses of epidural morphine were studied in order to determine their effectiveness in providing postoperative pain relief after surgery of the lower extremities and their relationship to the incidence of untoward reactions. The study was carried out in a double-blind fashion using five dosages of epidural morphine (0.5, 1.0, 2.0, 4.0, and 8.0 mg) and included 60 patients. The higher doses of morphine (2.0, 4.0, and 8.0 mg) were equally effective and more effective than the lower doses (0.5 and 1.0 mg) in providing postoperative analgesia. Nausea and vomiting were encountered more frequently with the highest dose (8.0 mg) and this finding was statistically significant (P less than 0.03). No statistically significant difference was found between the doses studied with regard to itching, urinary retention, and respiratory depression; the latter was evaluated in a subgroup of 20 patients. These data suggest that effective postoperative pain relief after surgery of the lower extremities can be achieved with relatively low doses of morphine sulfate and with minimal side effects. For the type of surgery studied, 2 mg morphine sulfate appeared to be the optimum dose.

Long-term intrathecal infusion of morphine and morphine/bupivacaine mixtures in the treatment of cancer pain: a retrospective analysis of 51 cases.

A retrospective analysis of 51 patients with cancer pain treated with a continuous i.t. morphine infusion through a tunnelled percutaneous catheter was undertaken. Because of insufficient pain relief with morphine only, 17 of these patients received a morphine/bupivacaine mixture. pain relief subsequently improved significantly in 10 patients and a moderate improvement was present in 4 patients. An additional analgesic effect of bupivacaine was not shown in 3 patients with clinical signs of severe mental depression. Bupivacaine-induced side effects were absent below a daily dosage of 30 mg by continuous infusion. In all patients a gradual dose increment was observed. No serious complications, neurologic sequelae or meningitis occurred. It is concluded that long-term i.t. infusion of morphine through a tunnelled catheter can provide adequate pain relief in cancer patients with an acceptable risk-benefit ratio. The effects of long-term intrathecal co-administration of local anesthetics, especially bupivacaine, await further prospective evaluation.