Peak Pain Scores Research Articles

Efficacy of a Prophylactic Epidural Blood Patch in Preventing Post Dural Puncture Headache in Parturients after Inadvertent Dural Puncture

Postdural puncture headache (PDPH) occurs in up to 80% of parturients who experience inadvertent dural puncture during epidural catheter placement. The authors performed a randomized double blind study to assess the effect of prophylactic epidural blood patch on the incidence of PDPH and the need for therapeutic epidural blood patch. Sixty-four parturients who incurred inadvertent dural puncture were randomized to receive a prophylactic epidural blood patch with 20 ml autologous blood (prophylactic epidural blood patch group) or a sham patch (sham group). Subjects were evaluated daily for development of PDPH for a minimum of 5 days after dural puncture. Those who developed a PDPH were followed daily for a minimum of 3 days after resolution of the headache. Subjects with moderate headaches who reported difficulties performing childcare activities and all those with severe headaches were advised to receive a therapeutic epidural blood patch. Eighteen of 32 subjects in each group (56%) developed PDPH. Therapeutic blood patch was recommended in similar numbers of patients in each group. The groups had similar onset time of PDPH, median peak pain scores, and number of days spent unable to perform childcare activities as a result of postural headache. The median duration of PDPH, however, was shorter in the prophylactic epidural blood patch group. A decrease in the incidence of PDPH or the need for criteria-directed therapeutic epidural patch was not detected when a prophylactic epidural blood patch was administered to parturients after inadvertent dural puncture. However, prophylactic epidural blood patch did shorten the duration of PDPH symptoms.

Effect of muscle relaxants on experimental jaw-muscle pain and jaw-stretch reflexes: a double-blind and placebo-controlled trial

A randomised, double-blind, placebo-controlled three-way cross-over study was performed to investigate the effect of two muscle relaxants (tolperisone hydrochloride and pridinol mesilate) on experimental jaw-muscle pain and jaw-stretch reflexes. Fifteen healthy men participated in three randomised sessions separated by at least 1 week. In each session 300 mg tolperisone, 8 mg pridinol mesilate or placebo was administered orally as a single dose. One hour after drug administration 0.3 ml hypertonic saline (5.8%) was injected into the right masseter to produce muscle pain. Subjects continuously rated their perceived pain intensity on an electronic 10-cm visual analogue scale (VAS). The pressure pain threshold (PPT) was measured and short-latency reflex responses were evoked in the pre-contracted (15% maximal voluntary contraction) masseter and temporalis muscles by a standardised stretch device (1 mm displacement, 10 ms ramp time) before (baseline), 1 h after medication (post-drug), during ongoing experimental muscle pain (pain-post-drug), and 15 min after pain had vanished (post-pain). Analysis of variance demonstrated significantly lower VAS peak pain scores (5.9±0.4 cm) after administration of tolperisone hydrochloride compared with pridinol mesilate (6.8±0.4 cm) and placebo (6.6±0.4 cm) ( P=0.020). Administration of pridinol mesilate was associated with a significant decrease in PPTs compared with tolperisone hydrochloride and placebo ( P=0.002) after medication, but not after experimental jaw-muscle pain. The normalised peak-to-peak amplitude of the stretch reflexes were not significantly influenced by the test medication ( P=0.762), but were in all sessions significantly facilitated during ongoing experimental jaw-muscle pain ( P=0.034). In conclusion, tolperisone hydrochloride provides a small, albeit significant reduction in the perceived intensity of experimental jaw-muscle pain whereas the present dose had no effect on the short-latency jaw-stretch reflex.

Cimetidine for chronic calcifying tendinitis of the shoulder

Background and Objectives: Calcium deposits of the shoulder may persist for many years with resulting pain and impairment of mechanical function. The effects of different treatments vary significantly and do not show consistent and reliable long-term results. Cimetidine decreases calcium levels and improves symptoms in patients with hyperparathyroidism. We evaluated cimetidine as a treatment for chronic calcifying tendinitis of the shoulder in patients who did not respond to conservative treatment. Methods: Cimetidine, 200 mg twice daily, was given orally for 3 months in 16 patients who did not respond to more than 6 months of conservative treatment. We recorded subjective, functional, and radiologic findings at 1 day before, at 2 weeks after, and at 2 and 3 months after the start of cimetidine. We also performed a follow-up study (4 to 24 months). Results: After treatment, peak pain score (visual analogue scale: 0 - 100) decreased significantly from 63 ± 13 to 14 ± 19 (mean ± SD, P < .01) and 10 patients (63%) became pain free. Physical impairment was also significantly improved. Calcium deposits disappeared in 9 patients (56%), decreased in 4 patients (25%), and did not change in 3 patients (19%). Follow-up data showed that improvement of symptoms was sustained. No recurrence or enlargement of calcium deposits was observed. Plasma concentrations of calcium and parathyroid hormone did not change significantly. Conclusions: Our results indicate that cimetidine is effective in treating chronic calcifying tendinitis of the shoulder; however, the mechanism by which cimetidine improves the symptoms is unknown. Reg Anesth Pain Med 2003;28:248-252.

Evaluation of intraperitoneal and subcutaneous lidocaine and bupivacaine for analgesia following ovariohysterectomy in the dog

Many dogs in private practice undergo ovariohysterectomy (OHE) without analgesics. The purpose of this study was to determine if intraperitoneal (IP) and subcutaneous (SQ) lidocaine or bupivacaine provide analgesia following OHE. Thirty dogs presenting to the Veterinary Teaching Hospital for elective OHE were included in the study. All dogs were pre-medicated with acepromazine and butorphanol IM, induced with thiopental, and maintained with isoflurane. Dogs were randomly assigned to three groups: 10 received 8.8 mg kg−1 2% lidocaine with epinephrine IP (LID), 10 received 2.2 mg kg−1 0.75% bupivacaine IP (BUP), and 10 received 0.9% saline IP (SAL) upon completion of OHE. All IP doses were standardized to 0.88 mL kg−1 with saline. An additional 2 mL of the assigned solution was placed SC as a splash block prior to incisional closure. Dogs were scored at 0.5, 1, 2, 3, 6, 8, and 18 hours post-extubation by one observer blinded to treatment status. Dogs were evaluated using a visual analogue scale (VAS) for pain and sedation, and a scoring system that included physiologic and behavioral variables. Dogs were given supplemental analgesia with 0.22 mg kg−1 butorphanol ± acepromazine if their VAS (pain) score was >50. Parametric variables were analyzed using Student's t-test or Repeated Measures anova as appropriate. Nonparametric variables were analyzed by χ2-test. There were no significant differences in age, weight, incision length, surgery time, anesthesia time, or total thiopental dose between groups. Peak pain scores for all groups occurred at 0.5 hour and returned to baseline by 18 hours. Dogs in the BUP group had significantly lower pain scores at 0.5 hour than did dogs in the SAL group. Seven out of 10 dogs in the SAL group, 4 out of 10 dogs in the LID group, and 2 out of 10 dogs in the BUP group were given supplemental analgesia. No adverse side-effects were observed. Our findings supported the use of IP and SC bupivacaine for post-operative analgesia following OHE in the dog.

Electrical spinal-cord stimulation for painful diabetic peripheral neuropathy

Conventional treatment for painful peripheral diabetic neuropathy is largely symptomatic and often ineffective, with unacceptable side-effects. We tested electrical spinal-cord stimulation for the management of chronic neuropathic pain. Ten diabetic patients who did not respond to conventional treatment (mean age 51 [SD 9.3] years, six with type II diabetes, mean duration of diabetes 12 [6.3] years, mean duration of neuropathy 5 [2.1] years) were studied. The electrode was implanted in the thoracic/lumbar epidural space. Immediate neuropathic pain relief was assessed by visual analogue scale (VAS) after connecting the electrode, in a random order, to a percutaneous electrical stimulator or to a placebo stimulator. Exercise tolerance was assessed on a treadmill. Eight subjects had statistically significant pain relief with the electrical stimulator (p < 0.02) and were therefore converted to a permanent system. Statistically significant relief of both background and peak neuropathic pain was achieved at 3 months (n = 7, p = 0.016), at 6 months (n = 7, p = 0.03), and at the end of the study (14 months, n = 7, background pain p = 0.06, peak pain p = 0.03). One patient died 2 months after the start of the study of unrelated cause while continuing to benefit from treatment and another patient ceased to benefit at 4 months. McGill pain questionnaire scores with the stimulator turned off did not change significantly from baseline scores, indicating that the severity of the underlying pain was unaltered. However, with the stimulator turned on, there was a statistically significant (p < 0.05) improvement in all four components of the score, by the end of the study. At the end of the study, six patients continued to gain significant pain relief and used the stimulator as the sole treatment for their neuropathic pain. For example, median background and peak pain scores at the end of study, were, respectively, 77 and 81 with the stimulator off and 23 and 20 with the stimulator on. Exercise tolerance significantly improved at 3 months (n = 7, median % increase 85 [IQR, 62-360], p = 0.015) and at 6 months (n = 6, 163 [61-425], p = 0.0007). Electrophysiological tests, vibration perception-threshold, and glycaemic control were unchanged. Electrical spinal-cord stimulation offers a new and effective way of relieving chronic diabetic neuropathic pain and improves exercise tolerance. The technique should be considered in patients with neuropathic pain who do not respond to conventional treatment.