The use of analgesics in patients with acute abdominal pain. Lack of analgesic effect of opioids on neuropathic and idiopathic forms of pain. Effects of morphine analgesia on diagnostic accuracy in Emergency Department patients with abdominal pain: a prospective, randomized trial. Patient-controlled analgesia in children and adolescents: a randomized, prospective comparison with intramuscular administration of morphine for postoperative analgesia. A statistical model for pain in patient-controlled analgesia and conventional intramuscular opioid regimens. Randomized clinical trial of morphine in acute abdominal pain. Opioid substitution to improve the effectiveness of chronic noncancer pain control: a chart review. Long-term oral opioid therapy in patients with chronic nonmalignant pain.
Analgesics in patients with acute abdominal pain are often withheld for fear that they may change physical examination findings and thus may be unsafe. We conducted a randomized, prospective, placebo-controlled trial to investigate changes in physical examination following the administration of placebo, 5 mg, or 10 mg of morphine to 49 patients with acute abdominal pain. One patient was withdrawn secondary to inadequate documentation. Of the 48 patients who completed the trial, a statistically significant change in physical examination was noted in both groups receiving analgesics, but not in the placebo group. No adverse events or delays in diagnosis were attributed to the administration of analgesics. We conclude that physical examination does change after the administration of analgesics in patients with acute abdominal pain and that a larger study is needed to evaluate analgesic safety in this subpopulation of emergency department patients. The aim of the present study has been to assess the responsiveness of various types of chronic pain to opioids given i.v. and tested against placebo in a double-blind, randomized fashion. Pain classified as primary nociceptive was effectively alleviated (P greater than 0.001) while neuropathic deafferentation pain was not significantly influenced by morphine or equivalent doses of other opioids. Also 'idiopathic' pain, defined as chronic pain with no or little demonstrable pathology, failed to respond. The results were not related to whether the patients were regular users of narcotic analgesics or not. The outcome of our double-blind opioid test has proved useful to justify a continued, or discontinued, use of narcotic medication in individual patients. It may also support the indication and choice of invasive stimulation procedures (spinal cord or brain). The results of the study illustrate the misconception of chronic pain as an entity and highlight the importance of recognizing different neurobiological mechanisms and differences in responsiveness to analgesic drugs as well as to non-pharmacological modes of treatment. The opioid test has thus become a valuable tool in pain analysis and helpful as a guide for further treatment. Because of concerns about masking important physical findings, there is controversy surrounding whether it is safe to provide analgesia to patients with undifferentiated abdominal pain. The purpose of this study was to address the effects of analgesia on the physical examination and diagnostic accuracy for patients with abdominal pain.
                The study was a prospective, double-blind clinical trial in which adult Emergency Department (ED) patients with undifferentiated abdominal pain were randomized to receive placebo (control group, n = 36) or morphine sulphate (MS group, n = 38). Diagnostic and physical examination assessments were recorded before and after a 60-minute period during which study medication was titrated. Diagnostic accuracy and physical examination changes were compared between groups using univariate statistical analyses.
                There were no differences between control and MS groups with respect to changes in physical or diagnostic accuracy. The overall likelihood of change in severity of tenderness was similar in MS (37.7%) as compared with control (35.3%) patients (risk ratio [RR] 1.07, 95% confidence interval [CI] 0.64-1.78). MS patients were no more likely than controls to have a change in pain location (34.0% versus 41.2%, RR 0.82, 95% CI 0.50-1.36). Diagnostic accuracy did not differ between MS and control groups (64.2% versus 66.7%, RR 0.96, 95% CI 0.73-1.27). There were no differences between groups with respect to likelihood of any change occurring in the diagnostic list (37.7% versus 31.4%, RR 1.20, 95% CI 0.71-2.05). Correlation with clinical course and final diagnosis revealed no instance of masking of physical examination findings.
                Results of this study support a practice of early provision of analgesia to patients with undifferentiated abdominal pain.
                Copyright 2003 by the American College of Surgeons A randomized, prospective trial of patient-controlled analgesia (PCA), that is, a method of analgesia administration involving a computer-driven pump activated by patients to receive small doses within defined limits was performed in 82 children and adolescents after major orthopedic surgery to compare (1) intramuscularly administered morphine, (2) PCA morphine and (3) PCA morphine with a low-dose continuous morphine infusion (PCA-plus). Patients receiving PCA and PCA-plus had lower pain scores and greater satisfaction than patients receiving intramuscularly administered morphine. The three groups used equal amounts of morphine and most measures of recovery were identical in the groups. In particular, PCA and PCA-plus did not increase the incidence of opioid-related complications, and patients receiving PCA-plus were less sedated than patients receiving intramuscular therapy. We conclude that PCA and PCA-plus are safe and effective methods of pain relief in children and adolescents after orthopedic surgery, are better accepted than intramuscular injections, and do not increase perioperative morbidity. A statistical model was developed: 1) to compare the efficacy of patient-controlled analgesia (PCA) and traditional intramuscular (IM) opioids for pain relief in 40 patients after total knee replacement and, 2) to evaluate pain cycles associated with each technique. Hourly visual analog pain scores were subjected to two-way analysis of variance (ANOVA) and time-series analysis. Hourly verbal analog pain scores were used to determine predominant pain levels. According to ANOVA, PCA was no more effective than were IM opioids. Time-series analyses documented a complete cycle of pain every 5.3 hours in patients receiving IM opioids but no pain cycle with use of PCA. Analysis of PCA verbal analog scores demonstrated self-administration of opioids to "moderate" levels of pain relief with use of PCA, not to complete analgesia. These results suggest that certain patients may not envision complete postoperative analgesia as being possible. Hence, they self-administer opioids for pain relief with PCA according to their expectations. Population characteristics may modify PCA efficacy. These characteristics should be delineated and the use of PCA targeted to appropriate patients. Administration of analgesia to patients with acute abdominal pain is controversial. We test the hypothesis that morphine given to emergency department (ED) patients with acute abdominal pain will reduce discomfort and improve clinically important diagnostic accuracy.
                Pain was measured with a standard 0- to 100-mm visual analog scale. ED patients with acute abdominal pain were randomized in a double-blind fashion to 0.1 mg/kg intravenous morphine or placebo. The primary endpoint was the difference between the 2 study arms in clinically important diagnostic accuracy. Clinically important diagnostic accuracy was defined a priori by its complement, clinically important diagnostic error, using 2 independent, blinded investigators to identify any discordance between the provisional and final diagnoses that might adversely affect the patient's health status. The provisional diagnosis was provided by an ED attending physician, who examined the patient only once, 15 minutes after administration of the study agent. The final diagnosis was obtained through follow-up at least 6 weeks after the index ED visit.
                We randomized 160 patients, of whom 153 patients were available for analysis, 78 patients in the morphine group and 75 patients in the placebo group. Baseline features were similar in both groups, including initial median visual analog scale scores of 98 mm and 99 mm. The median decrease in visual analog scale score at 15 minutes was 33 mm in the morphine group and 2 mm in the placebo group. There were 11 instances of diagnostic discordance in each group, for a clinically important diagnostic accuracy of 86% (67/78) in the morphine group and 85% (64/75) in the placebo group. The difference in clinically important diagnostic accuracy between the 2 groups was 1% (95% confidence interval [CI] -11% to 12%). Analysis by efficacy and intention to treat yielded similar results. Kappa for interobserver concordance in classification of clinically important diagnostic accuracy was 0.94 (95% CI 0.79 to 1.00). No patients required naloxone.
                Although administration of intravenous morphine to adult ED patients with acute abdominal pain could lead to as much as a 12% difference in diagnostic accuracy, equally favoring opioid or placebo, our data are most consistent with the inference that morphine safely provides analgesia without impairing clinically important diagnostic accuracy. We evaluated the efficacy and tolerability of opioids in the long-term management of chronic noncancer pain. This retrospective chart review included 86 outpatients who started receiving, between 1994 and 1998, long-acting opioids. For each patient, the number of different opioids used and the efficacy and tolerability of each opioid prescribed were noted. During a mean follow-up of 8.8 +/- 6.3 mo, the number of opioids used by each patient was 2.3 +/- 1.4. Patient diagnoses were: back pain (31), neuropathy (20), joint pain (13), visceral pain (7), reflex sympathetic dystrophy (7), headache (5), fibromyalgia (3). The first opioid prescribed was effective for 36% of patients, was stopped because of side effects in 30%, and was stopped for ineffectiveness in 34%. Of the remaining patients, the second opioid prescribed after the failure of the first was effective in 31%, the third in 40%, the fourth in 56%, and the fifth in 14%. There was one case of addiction and no case of tolerance. We conclude that if it is necessary to change the opioid prescription because of intolerable side effects or ineffectiveness, the cumulative percentage of efficacy increases with each new opioid tested. Failure of one opioid cannot predict the patient's response to another. Implications: This study showed that if a patient receiving chronic opioid therapy experiences an intolerable side effect or if the drug is ineffective, changing to a different opioid may result in a lessening or elimination of the side effect and/or improved analgesia. In contrast to the use of opioids for the treatment of acute and chronic cancer pain, the administration of chronic opioid therapy for pain not due to malignancy remains controversial. We describe 100 patients who were chronically given opioids for treatment of nonmalignant pain. Most patients experienced neuropathic pain or back pain. We used sustained-release dihydrocodeine, buprenorphine, and sustained-release morphine. Pain reduction was measured with visual analogue scales (VAS), and the Karnofsky Performance Status Scale was used to assess the patient's function. Good pain relief was obtained in 51 patients and partial pain relief was reported by 28 patients. Only 21 patients had no beneficial effect from opioid therapy. There was a close correlation between the sum and the peak VAS values (r = 0.983; p less than 0.0001) and pain reduction was associated with an increase in performance (p less than 0.0001). The most common side effects were constipation and nausea. There were no cases of respiratory depression or addiction to opioids. Our results indicate that opioids can be effective in chronic nonmalignant pain, with side effects that are comparable to those that complicate the treatment of cancer pain.
The use of opioid analgesics in the therapeutic diagnosis of patients with AAP does not increase the risk of diagnosis error or the risk of error in making decisions regarding treatment.