Luis Romundstad

Assessment of pain

UNLABELLED Valid and reliable assessment of pain is essential for both clinical trials and effective pain management. The nature of pain makes objective measurement impossible. Acute pain can be reliably assessed, both at rest (important for comfort) and during movement (important for function and risk of postoperative complications), with one-dimensional tools such as numeric rating scales or visual analogue scales. Both these are more powerful in detecting changes in pain intensity than a verbal categorical rating scale. In acute pain trials, assessment of baseline pain must ensure sufficient pain intensity for the trial to detect meaningful treatment effects. Chronic pain assessment and its impact on physical, emotional, and social functions require multidimensional qualitative tools and health-related quality of life instruments. Several disease- and patient-specific functional scales are useful, such as the Western Ontario and MacMaster Universities for osteoarthritis, and several neuropathic pain screening tools. The Initiative on METHODS Measurement, and Pain Assessment in Clinical Trials recommendations for outcome measurements of chronic pain trials are also useful for routine assessment. Cancer pain assessment is complicated by a number of other bodily and mental symptoms such as fatigue and depression, all affecting quality of life. It is noteworthy that quality of life reported by chronic pain patients can be as much affected as that of terminal cancer patients. Any assessment of pain must take into account other factors, such as cognitive impairment or dementia, and assessment tools validated in the specific patient groups being studied.

Persistent postsurgical pain in a general population: prevalence and predictors in the Tromsø study.

TOC summary Persistent pain after surgery is common, but prevalence of clinically relevant pain may be overestimated. Sensory abnormalities are associated with pain and more intense pain. ABSTRACT Population‐based data on the prevalence of persistent postsurgical pain are scarce. This study aimed to assess the prevalence of persistent postsurgical pain in a general population and to describe associated physical, social, and psychological factors, including symptoms of nerve injury and sensitization. A cross‐sectional survey was performed in northern Norway with questionnaire items covering surgery, pain, and sensory abnormalities in the area of surgery. Of the 12,982 participants, 24.0% (3111) had undergone one or more surgical procedures during the 3 years preceding the survey. Of these, 2043 had the surgery performed more than 3 months before the investigation. Persistent pain in the area of surgery was reported by 40.4% of the patients (826 of 2043), moderate or severe pain by 18.3% (373 of 2043). Hypoesthesia, hyperesthesia, or both was reported by 24.5% (501 of 2043). There were strong associations between sensory abnormalities and persistent pain, increasingly with higher pain intensities; odds ratios were 2.68 for hypoesthesia and 6.27 for hyperesthesia. Of the 826 individuals reporting persistent pain in the anatomical area of surgery, 51.0% reported chronic pain when questioned without specific reference to the surgery. The present study supports evidence from clinical studies of persistent postsurgical pain, indicating a high prevalence, but reveals large discrepancies in report of pain, depending on the questions asked and the context in which the questions are presented. Strong associations between sensory abnormalities and pain indicate neuropathic mechanisms in a major proportion of cases.

Methylprednisolone intravenously 1 day after surgery has sustained analgesic and opioid-sparing effects

Background:  In previous studies on glucocorticoids for postoperative pain, the test drug has been given perioperatively, usually before measurement of baseline pain. In order to evaluate the time course and magnitude of the analgesic effect of a glucocorticoid in well‐established postoperative pain, we compared methylprednisolone with ketorolac and placebo, after assessment of baseline pain on the first postoperative day.

Chronic pain and sensory changes after augmentation mammoplasty: long term effects of preincisional administration of methylprednisolone.

Abstract We studied the prevalence of chronic pain and long term sensory changes after cosmetic augmentation mammoplasty and the effects of a single i.v. preoperative dose of methylprednisolone 125 mg (n = 74), parecoxib 40 mg (n = 71), or placebo (n = 74). A questionnaire was mailed 6 weeks and 1 year after surgery. Response rate after 1 year was 80%. At 1 year non‐evoked pain was present in 13%, and evoked pain was present in 20% with no statistically significant differences between the groups. Methylprednisolone was associated with reduced odds for hyperesthesia at 1 year (OR 0.3, 95% CI 0.1–0.6), and significantly reduced the prevalence of hyperesthesia (30%) compared with placebo (56%, P < 0.01) and parecoxib (51%, P < 0.04). Factors associated with increased odds for pain at 1 year were intensity of pain during the first 6 days after surgery (OR 1.3, 95% CI 1.1–1.6), pain at 6 weeks (OR 18.4, 95% CI 6.9–49.3), hyperesthesia at 6 weeks (OR 2.3, 95% CI 1.1–5.1) and present hyperesthesia (OR 3.1, 95% CI 1.4–6.7). We conclude that persistent pain and sensory changes are common after augmentation mammoplasty, and that patients having pain at 6 weeks most likely will have pain also at 1 year. Acute postoperative pain, hyperesthesia at 6 weeks, and the presence of hyperesthesia increased the odds for pain at 1 year. Preoperative methylprednisolone resulted in significantly less hyperesthesia compared with both parecoxib and placebo, but did not significantly reduce the prevalence of persistent spontaneous or evoked pain.

Methylprednisolone reduces pain, emesis, and fatigue after breast augmentation surgery : A single-dose, randomized, parallel-group study with methylprednisolone 125 mg, parecoxib 40 mg, and placebo

We compared methylprednisolone 125 mg IV (n = 68) and parecoxib 40 mg IV (n = 68) with placebo (n = 68) given before breast augmentation surgery in a randomized, double-blind parallel group study. Surgery was performed under local anesthesia combined with propofol/fentanyl sedation. Methylprednisolone and parecoxib decreased pain at rest and dynamic pain intensity from 1 to 6 h after surgery compared with placebo (mean summed pain intensity1–6 h: methylprednisolone [17.25; 95% confidence interval [CI], 14.85–19.65] versus placebo [21.7; 95% CI, 19.3–24.1]; P < 0.03; parecoxib [15.25; 95% CI, 13.25–17.25] versus placebo; P < 0.001; mean summed dynamic pain intensity1–6 h: methylprednisolone [22.7; 95% CI, 20.1–23.3] versus placebo [28.4; 95% CI, 26.0–30.8]; P < 0.01; parecoxib [20.9; 95% CI, 18.6–23.2] versus placebo; P < 0.001). Both rescue drug consumption and actual pain (all observations before and after rescue) during the first 6 h were similar in the two active drug groups and significantly reduced compared with placebo. Using a composite score of actual pain intensity and rescue analgesic use, the active drugs were significantly superior to placebo (P < 0.001 for both active drugs). Postoperative nausea and vomiting was reduced after methylprednisolone administration (incidence, 30%), but not after parecoxib (incidence, 37%), during the first 24 h compared with placebo (incidence, 60%; P < 0.001). Fatigue was reduced by methylprednisolone (incidence, 44%), but not by parecoxib (incidence, 59%), compared with placebo (incidence, 66%; P < 0.05). In conclusion, methylprednisolone 125 mg IV given before breast augmentation surgery had analgesic and rescue analgesic-sparing effects comparable with those of parecoxib 40 mg IV. Methylprednisolone, but not parecoxib, reduced nausea, vomiting, and fatigue.

Methylprednisolone and ketorolac rapidly reduce hyperalgesia around a skin burn injury and increase pressure pain thresholds

Background:  Glucocorticoids and non‐steroidal anti‐inflammatory drugs (NSAIDs) decrease acute postoperative pain and hyperalgesia. The objectives of this study were to investigate the effects of methylprednisolone and ketorolac on hyperalgesia around a skin burn injury and on pressure pain thresholds.

Adding propacetamol to ketorolac increases the tolerance to painful pressure.

Combining an NSAID and paracetamol (acetaminophen) has in some studies given superior analgesia compared with the single drugs. In other trials no additive effect has been found. We have investigated the effect of this drug combination on the pressure pain tolerance threshold (PPTT), a reproducible correlate to clinical pain.

Hyperesthesia one year after breast augmentation surgery increases the odds for persisting pain at four years A prospective four-year follow-up study

Abstract In this long-term follow-up study of 175 women, we investigated the prevalence of and factors associated with persisting pain and sensory changes four years after augmentation mammoplasty. Previously the women had participated in an acute postoperative pain study, and follow-up investigations at 6 weeks and 1 year after surgery. In the present study, the women were mailed questionnaires about pain, sensory changes, and affection of daily life, quality of life and pain catastrophizing 4 years after surgery. One hundred and sixteen women answered the questionnaire. The fraction of women reporting evoked- and/or spontaneous pain during the last 24 h had declined from 20% at 1 year to 14% at 4 years. Hyperesthesia had declined from 46% at 1 year to 32% at 4 years, while the change in hypoesthesia was small, 47% at 1 year to 51% at 4 years. Methylprednisolone and parecoxib given pre incisionally reduced acute postoperative pain and reduced the prevalence of hyperesthesia after 6 weeks/1 year, but after 4 years we found no significant differences between the test drug groups. Those having concomitant pain and hyperesthesia at 6 weeks and 1 year had high odds for persisting pain at 4 years (OR 7.8, 95% CI 2.1–29.8, P = 0.003; OR 13.2, 95% CI 2.5–71.3, P = 0.003). In patients without pain but with hyperesthesia at 1 year, the hyperesthesia increased the odds for pain at 4 years (OR 2.6 95% CI 1.1–6.1, P = 0.03). Hypoesthesia at 6 weeks or at 1 year did not affect the odds for pain at 4 years. A good general health condition (mental and physical) was associated with reduced odds for pain at 4 years (OR = 0.56, 95% CI 0.35–0.88, P = 0.01). However, using the Short Form health survey, SF-12, the Mental Component Summary Score seemed to affect the odds for chronic pain more than the Physical Component Summary Score. To conclude, the prevalence of pain and hyperesthesia after breast augmentation declined from 1 to 4 years. Nevertheless, the most striking finding in the current trial was that pain coinciding with hyperesthesia at 6 weeks and 1 year resulted in highly increased odds for persistent postoperative pain. Even hyperesthesia alone, without pain, increased the odds for chronic postsurgical pain. Thus, the present study suggests hyperesthesia as an independent risk factor for chronic postsurgical pain.

The Shamrock lumbar plexus block: A dose-finding study

BACKGROUND The Shamrock technique is a new method for ultrasound-guided lumbar plexus blockade. Data on the optimal local anaesthetic dose are not available. OBJECTIVE The objective of this study is to estimate the effective dose of ropivacaine 0.5% for a Shamrock lumbar plexus block. DESIGN A prospective dose-finding study using Dixons up-and-down sequential method. SETTING University Hospital Orthopaedic Anaesthesia Unit. INTERVENTION Shamrock lumbar plexus block performance and block assessment were scheduled preoperatively. Ropivacaine 0.5% was titrated with the Dixon and Massey up-and-down method using a stepwise change of 5 ml in each consecutive patient. Combined blocks of the femoral, the lateral femoral cutaneous and the obturator nerve were prerequisite for a successful lumbar plexus block. PATIENTS Thirty patients scheduled for lower limb orthopaedic surgery completed the study. MAIN OUTCOME MEASURES The minimum effective anaesthetic volume of ropivacaine 0.5% (ED50) to achieve a successful Shamrock lumbar plexus block in 50% of the patients. Further analysis of the data was performed with a logistic regression model to calculate ED95 and to estimate the effective doses for a sensory lumbar plexus block not requiring a motor block of the femoral nerve. RESULTS The Dixon and Massay estimate of the ED50 was 20.4 [95% confidence interval (95% CI) 13.9 to 30.0] ml ropivacaine 0.5%. The logistic regression estimate of the ED95 was 36.0 (95% CI 19.7 to 52.2) ml ropivacaine 0.5%. For a sensory lumbar plexus block, the ED50 was 17.1 (95% CI 12.3 to 21.9) ml and the ED95 was 25.8 (95% CI 18.6 to 33.1) ml. CONCLUSION A volume of 20.4 ml ropivacaine 0.5% provided a successful Shamrock lumbar plexus block in 50% of the patients. A volume of 36.0 ml would be successful in 95% of the patients. TRIAL REGISTRATION ClinicalTrials.gov identifier NCT01956617.

Dexamethasone has additive effect when combined with ondansetron and droperidol for treatment of established PONV

Prophylactic dexamethasone, ondansetron and droperidol have a documented effect on post‐operative nausea and vomiting (PONV). Still, there is a lack of studies investigating the effect of adding dexamethasone to ondansetron and droperidol in order to treat established PONV.