Postoperative analgesics for superficial surgery. Comparison of four analgesics

Efficacy of early intravenous bolus oxycodone or fentanyl in emergence from general anaesthesia and postoperative analgesia following laparoscopic cholecystectomy: A randomized trial

OBJECTIVES

To compare prospectively the efficacy of early intravenous bolus of oxycodone or fentanyl in providing analgesia at emergence from general anaesthesia following laparoscopic cholecystectomy.

METHODS

Patients were randomly assigned to receive either 0.08 mg/kg oxycodone (Group O) or 1 µg/kg fentanyl (Group F), 20 min before the end of surgery. Postoperative pain was evaluated using a visual analogue scale (VAS). The time to first postoperative analgesic dose, requirement for analgesia and side-effects were assessed in the postanaesthesia care unit (PACU).

RESULTS

The VAS scores at 0 min and 30 min and requirement for analgesia were significantly lower in Group O (n = 28) than in Group F (n = 26). The time to first analgesia dose was significantly longer in Group O than Group F. There were no significant between-group differences in the incidence of side-effects.

CONCLUSIONS

Oxycodone relieves immediate postoperative pain significantly better than fentanyl, and is not associated with an increase in side-effects in patients undergoing laparoscopic cholecystectomy.

Comparing the efficacy of intravenous acetaminophen and intravenous meperidine in pain relief after outpatient urological surgery

Background:

Pain relief after surgery is an essential component of postoperative care.

Objectives:

The purpose of this study was to compare the efficacy of intravenous acetaminophen and intravenous meperidine in pain relief after outpatient urological surgery.

Patients and Methods:

In a prospective, randomized, double-blind clinical trial, 100 outpatients of urological surgery were studied in two groups of acetaminophen (A) and meperidine (M). Patients in group A received 1g of acetaminophen in 100 mL saline within 15 minutes and patients in group M received a single intravenous injection of meperidine 0.5 mg/kg, 15 minutes prior to the end of operation. Postoperative pain was recorded using visual analog scale (VAS). Vital signs, nausea, vomiting, dizziness and respiratory depressions were compared between the two groups.

Results:

Pain severity in patients treated with intravenous acetaminophen six hours after the operation within one-hour interval was significantly lower than meperidine group (P < 0.0001). Ninety patients in the meperidine group and five patients in the acetaminophen group required additional doses of analgesics. Nausea was significantly lower in acetaminophen group than meperidine group.

Conclusions:

Intravenous acetaminophen reduced pain following outpatient urological surgery more significantly than meperidine.

WITHDRAWN: Single dose dipyrone for acute postoperative pain

BACKGROUND

Dipyrone (metamizole) is a non‐steroidal anti‐inflammatory drug used in some countries to treat pain (postoperative, colic, cancer, and migraine); it is banned in others because of an association with life‐threatening blood agranulocytosis. This review updates a 2001 Cochrane review, and no relevant new studies were identified, but additional outcomes were sought.

OBJECTIVES

To assess the efficacy and adverse events of single dose dipyrone in acute postoperative pain.

SEARCH METHODS

The earlier review searched CENTRAL, MEDLINE, EMBASE, LILACS and the Oxford Pain Relief Database to December 1999. For the update we searched CENTRAL, MEDLINE,EMBASE and LILACS to February 2010.

SELECTION CRITERIA

Single dose, randomised, double‐blind, placebo or active controlled trials of dipyrone for relief of established moderate to severe postoperative pain in adults. We included oral, rectal, intramuscular or intravenous administration of study drugs.

DATA COLLECTION AND ANALYSIS

Studies were assessed for methodological quality and data extracted by two review authors independently. Summed total pain relief over six hours (TOTPAR) was used to calculate the number of participants achieving at least 50% pain relief. Derived results were used to calculate, with 95% confidence intervals, relative benefit compared to placebo, and the number needed to treat (NNT) for one participant to experience at least 50% pain relief over six hours. Use and time to use of rescue medication were additional measures of efficacy. Information on adverse events and withdrawals was collected.

MAIN RESULTS

Fifteen studies tested mainly 500 mg oral dipyrone (173 participants), 2.5 g intravenous dipyrone (101), 2.5 g intramuscular dipyrone (99); fewer than 60 participants received any other dose. All studies used active controls (ibuprofen, paracetamol, aspirin, flurbiprofen, ketoprofen, dexketoprofen, ketorolac, pethidine, tramadol, suprofen); eight used placebo controls. Over 70% of participants experienced at least 50% pain relief over 4 to 6 hours with oral dipyrone 500 mg compared to 30% with placebo in five studies (288 participants; NNT 2.4 (1.9 to 3.2)). Fewer participants needed rescue medication with dipyrone (7%) than with placebo (34%; four studies, 248 participants). There was no difference in participants experiencing at least 50% pain relief with 2.5 g intravenous dipyrone and 100 mg intravenous tramadol (70% vs 65%; two studies, 200 participants). No serious adverse events were reported.

AUTHORS' CONCLUSIONS

Based on very limited information, single dose dipyrone 500 mg provides good pain relief to 70% of patients. For every five individuals given dipyrone 500 mg, two would experience this level of pain relief who would not have done with placebo, and fewer would need rescue medication, over 4 to 6 hours.

[The role of non-opioid analgesics in the management of postoperative pain.]

At present, intramuscular application of opioids given on request is the most widespread form of postoperative analgesia. This method is widely recognized as often being inadequate, however. As advanced techniques of pain management, such as patient-controlled analgesia, are not generally available, the question arises as to whether non-opioid analgesics should routinely be used in order to improve this situation. A review of the literature indicates that apart from when used following abdominal surgery, in particular, operations on the biliary tract, non-steroidal anti-inflammatory drugs (NSAIDS) offer effective postoperative pain control. Following minor surgery, the quality of analgesia can be better than that achieved with the weak opioids. The discrepancy between biliary tract operations and all other forms of surgery raises the question whether in the former case pain may have been partly due to spasms of visceral smooth muscle and hence be less readily amenable to the action of NSAIDS. A potential problem with the perioperative use of NSAIDS is that they inhibit platelet aggregation. Apart from tonsillectomy, there are no reports of increased intra- or postoperative bleeding when these drugs have been used for minor surgery, and only isolated reports following major operations. Despite these results, it must be borne in mind that most studies have been carried out on patients of ASA groups I and II and that conclusions drawn from the literature are not necessarily representative for the elderly and for patients with organ failure. Alternative substances have received relatively little attention. Of these, the pyrazolone derivative, metamizol, may well prove to be of value for patients in whom the use of NSAIDS is contraindicated or relatively ineffective such as after biliary tract surgery.

Single dose dipyrone for acute postoperative pain

BACKGROUND

Dipyrone (metamizole) is a non-steroidal anti-inflammatory drug used in some countries to treat pain (postoperative, colic, cancer, and migraine); it is banned in others because of an association with life-threatening blood agranulocytosis. This review updates a 2001 Cochrane review, and no relevant new studies were identified, but additional outcomes were sought.

OBJECTIVES

To assess the efficacy and adverse events of single dose dipyrone in acute postoperative pain.

SEARCH STRATEGY

The earlier review searched CENTRAL, MEDLINE, EMBASE, LILACS and the Oxford Pain Relief Database to December 1999. For the update we searched CENTRAL, MEDLINE,EMBASE and LILACS to February 2010.

SELECTION CRITERIA

Single dose, randomised, double-blind, placebo or active controlled trials of dipyrone for relief of established moderate to severe postoperative pain in adults. We included oral, rectal, intramuscular or intravenous administration of study drugs.

DATA COLLECTION AND ANALYSIS

Studies were assessed for methodological quality and data extracted by two review authors independently. Summed total pain relief over six hours (TOTPAR) was used to calculate the number of participants achieving at least 50% pain relief. Derived results were used to calculate, with 95% confidence intervals, relative benefit compared to placebo, and the number needed to treat (NNT) for one participant to experience at least 50% pain relief over six hours. Use and time to use of rescue medication were additional measures of efficacy. Information on adverse events and withdrawals was collected.

MAIN RESULTS

Fifteen studies tested mainly 500 mg oral dipyrone (173 participants), 2.5 g intravenous dipyrone (101), 2.5 g intramuscular dipyrone (99); fewer than 60 participants received any other dose. All studies used active controls (ibuprofen, paracetamol, aspirin, flurbiprofen, ketoprofen, dexketoprofen, ketorolac, pethidine, tramadol, suprofen); eight used placebo controls.Over 70% of participants experienced at least 50% pain relief over 4 to 6 hours with oral dipyrone 500 mg compared to 30% with placebo in five studies (288 participants; NNT 2.4 (1.9 to 3.2)). Fewer participants needed rescue medication with dipyrone (7%) than with placebo (34%; four studies, 248 participants). There was no difference in participants experiencing at least 50% pain relief with 2.5 g intravenous dipyrone and 100 mg intravenous tramadol (70% vs 65%; two studies, 200 participants). No serious adverse events were reported.

AUTHORS' CONCLUSIONS

Based on very limited information, single dose dipyrone 500 mg provides good pain relief to 70% of patients. For every five individuals given dipyrone 500 mg, two would experience this level of pain relief who would not have done with placebo, and fewer would need rescue medication, over 4 to 6 hours.

Too much of a good thing: long-term treatment with salicylate strengthens outer hair cell function but impairs auditory neural activity

Aspirin has been extensively used in clinical settings. Its side effects on auditory function, including hearing loss and tinnitus, are considered as temporary. A recent promising finding is that chronic treatment with high-dose salicylate (the active ingredient of aspirin) for several weeks enhances expression of the outer hair cell (OHC) motor protein (prestin), resulting in strengthened OHC electromotility and enhanced distortion product otoacoustic emissions (DPOAE). To follow up on these observations, we carried out two studies, one planned study of age-related hearing loss restoration and a second unrelated study of salicylate-induced tinnitus. Rats of different strains and ages were injected with salicylate at a dose of 200 mg/kg/day for 5 days per week for 3 weeks or at higher dose levels (250-350 mg/kg/day) for 4 days per week for 2 weeks. Unexpectedly, while an enhanced or sustained DPOAE was seen, permanent reductions in the amplitude of the cochlear compound action potential (CAP) and the auditory brainstem response (ABR) were often observed after the chronic salicylate treatment. The mechanisms underlying these unexpected, permanent salicylate-induced reductions in neural activity are discussed.

Single dose oral oxycodone and oxycodone plus paracetamol (acetaminophen) for acute postoperative pain in adults

BACKGROUND

Oxycodone is a strong opioid agonist used to treat severe pain. It is commonly combined with milder analgesics such as paracetamol. This review updates a previous review that concluded, based on limited data, that all doses of oxycodone exceeding 5 mg, with or without paracetamol, provided analgesia in postoperative pain, but with increased incidence of adverse events compared with placebo. Additional new studies provide more reliable estimates of efficacy and harm.

OBJECTIVES

To assess efficacy, duration of action, and associated adverse events of single dose oral oxycodone, with or without paracetamol, in acute postoperative pain in adults.

SEARCH STRATEGY

Cochrane CENTRAL, MEDLINE, EMBASE and Oxford Pain Relief Database, searched in May 2009.

SELECTION CRITERIA

Randomised, double blind, placebo-controlled trials of single dose orally administered oxycodone, with or without paracetamol, in adults with moderate to severe acute postoperative pain.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data. Pain relief or pain intensity data were extracted and converted into the dichotomous outcome of number of participants with at least 50% pain relief over 4 to 6 hours, from which relative risk and number-needed-to-treat-to-benefit (NNT) were calculated. Numbers of participants remedicating over specified time periods, and time-to-use of rescue medication, were sought as additional measures of efficacy. Adverse events and withdrawals information was collected.

MAIN RESULTS

This updated review includes 20 studies, with 2641 participants. For oxycodone 15 mg alone compared with placebo, the NNT for at least 50% pain relief was 4.6 (95% Confidence Interval 2.9 to 11). For oxycodone 10 mg plus paracetamol 650 mg, the NNT was 2.7 (2.4 to 3.1). A dose response was demonstrated for this outcome with combination therapy. Duration of effect was 10 hours with oxycodone 10 mg plus paracetamol 650 mg, and 4 hours with half that dose. Fewer participants needed rescue medication over 6 hours at the higher dose. Adverse events occurred more frequently with combination therapy than placebo, but were generally described as mild to moderate in severity and rarely led to withdrawal.

AUTHORS' CONCLUSIONS

Single dose oxycodone is an effective analgesic in acute postoperative pain at doses over 5 mg; oxycodone is two to three times stronger than codeine. Efficacy increases when combined with paracetamol. Oxycodone 10 mg plus paracetamol 650 mg provides good analgesia to half of those treated, comparable to commonly used non-steroidal anti-inflammatory drugs, with the benefit of longer duration of action.

Single-dose dipyrone for acute postoperative pain

BACKGROUND

The use of dipyrone as an analgesic is controversial. It is used most commonly to treat postoperative pain, colic pain, cancer pain and migraine, and in many countries, eg, Russia, Spain, Brazil, and in many parts of South-America and Africa, it is the most popular non opioid first line analgesic. In others it has been banned (e.g. USA, UK) because of its association with potentially life-threatening blood dyscrasias such as agranulocytosis. Dipyrone is currently available in Austria, Belgium, France, Germany, Italy, The Netherlands, Spain, Switzerland, South Africa, Latin America, Russia, Israel and India.

OBJECTIVES

To assess quantitatively the analgesic efficacy and adverse effects of single-dose dipyrone in randomised trials in moderate to severe postoperative pain. To compare the relative efficacy of dipyrone with other drugs assessed in the same way.

SEARCH STRATEGY

Published reports were identified from Medline, Embase, the Cochrane Library (Issue 3 1999), LILACs and the Oxford Pain Relief Database. Additional studies were identified from bibliographies of retrieved reports. Date of the most recent search: December 1999.

SELECTION CRITERIA

The following inclusion criteria were used: full journal publication, clinical trial, random allocation of patients to treatment groups, double-blind design, adult patients, pain of moderate to severe intensity at the baseline assessment, postoperative administration of study drugs, treatment arms which included dipyrone and placebo or active control and oral, rectal, intramuscular or intravenous administration of study drugs.

DATA COLLECTION AND ANALYSIS

Summed pain intensity and pain relief data over 4-6 hours were extracted and converted into dichotomous information to yield the number of patients who obtained at least 50% pain relief. This was used to calculate the proportion of patients with, and number-needed-to-treat for, at least 50% pain relief over 4-6 hours. Single-dose adverse effect data were collected.

MAIN RESULTS

Fifteen studies were included; eight used placebo and seven used an active control (oral dexketoprofen 12.5 mg or 25 mg, oral ketorolac 10 mg, intramuscular pethidine 100 mg or ketorolac 30 mg, intravenous tramadol 100 mg or rectal suprofen 300 mg). In five trials (288 patients) the mean response rate (proportion of patients with at least 50% pain relief) for single dose oral dipyrone 500 mg was 73% (range 54% to 87%) and with placebo it was 32% (19% to 41%) in moderate to severe postoperative pain over 4-6 hours. In two studies (113 patients) the response rate with oral dipyrone 1 g was 69% (61% and 77%) and with placebo it was 20% (11% and 25%). In one study (70 patients) the response rate with intramuscular dipyrone 2 g was 74% and with placebo it was 46%. No analyses could be conducted for adverse effects. The response rates in the active controlled trials were similar to those reported in the placebo controlled trials.

REVIEWER'S CONCLUSIONS

Single-dose dipyrone appears to be of similar efficacy to ibuprofen 400 mg and other analgesics frequently used in the treatment of moderate to severe postoperative pain. The commonest adverse effects were somnolence, gastric discomfort and nausea.

Single dose oxycodone and oxycodone plus paracetamol (acetominophen) for acute postoperative pain

BACKGROUND

Oxycodone is a strong opioid agonist which is useful for the management of severe pain. It is becoming increasingly important to assess the relative efficacy and harm caused by different treatments. This can be determined when an analgesic is compared with control under similar clinical circumstances.

OBJECTIVES

To quantitatively assess the analgesic efficacy and adverse effects of single-dose oxycodone and oxycodone plus paracetamol in randomised trials in acute postoperative pain.

SEARCH STRATEGY

Published reports were identified from Medline, Biological Abstracts, Embase, the Cochrane Library and the Oxford Pain Relief Database. Additional studies were identified from the reference lists of retrieved reports.

SELECTION CRITERIA

The inclusion criteria were: full journal publication, clinical trial, random allocation of adult patients to treatment groups, double blind design, moderate to severe baseline pain, postoperative administration of study drugs, treatment arms which included oxycodone or oxycodone plus paracetamol and placebo (or active control for which comparable efficacy data exist), and oral, intramuscular or intravenous administration of study drugs.

DATA COLLECTION AND ANALYSIS

Summed pain intensity and pain relief data over 4-6 hours were extracted and converted into dichotomous information yielding the number of patients obtaining at least 50% pain relief. Estimates of relative benefit and number-needed-to-treat were calculated. Single-dose adverse effect data were collected.

MAIN RESULTS

Seventy-seven reports were identified. Seven reports met the inclusion criteria; all assessed oral oxycodone. For efficacy, a significant benefit of active drug over placebo was shown for all doses of oxycodone and oxycodone plus paracetamol, except oxycodone 5 mg. For adverse effects, the number of patients reporting adverse effects was extracted for each dose of active drug versus placebo. When these data were pooled for the individual doses significantly more adverse effects with active drug than with placebo were shown for all doses, except oxycodone 5 mg and its combination with paracetamol 325 mg. This was also shown for drowsiness/somnolence. Significantly more nausea, vomiting and dizziness/lightheadedness were reported with oxycodone 10 mg plus paracetamol (650 mg and 1000 mg) than with placebo.

REVIEWER'S CONCLUSIONS

Single-dose oral oxycodone, with or without paracetamol, appears to be of comparable efficacy to intramuscular morphine and non-steroidal anti-inflammatory drugs. Central nervous system adverse effects were common.

A risk-benefit appraisal of injectable NSAIDs in the management of postoperative pain

The inadequacy of pain treatment has been demonstrated in many patient groups suffering from acute pain. The injectable nonsteroidal anti-inflammatory drugs (NSAIDs), including indomethacin, diclofenac, ketoprofen and ketorolac, provide relief from the pain associated with several different conditions. When administered alone or in combination with low doses of opioids, NSAIDs provide good pain relief after musculoskeletal trauma or operation. The main advantage of these agents is that they may form the first-line therapy for pain relief and thus decrease the need of opioids. This avoids respiratory depression which can be associated with opioids. In contrast to opioids, NSAIDs do not cause respiratory depression or have marked adverse effects on the central nervous system. However, they may be associated with adverse effects of the gastrointestinal tract, liver and kidneys, and may increase pre- and postoperative bleeding and cause allergic reactions. These effects are related to the ability of NSAIDs to inhibit prostaglandin synthesis. Use of NSAIDs has to be considered carefully in patients with asthma, allergy to aspirin and NSAIDs, atopy, peptic ulcer or bleeding disorders (such as abnormalities in blood coagulation or coagulation deficits). These considerations are especially important in elderly patients. Having taken these contraindications into account, many clinical studies have demonstrated that NSAIDs are at least as safe as opioids when administered in the short term. However, few studies have specifically monitored adverse effects or included patients over 65 to 70 years of age. In addition, patients with risk factors have often been excluded from the trials. Therefore, the risk-benefit ratio of NSAIDs requires further assessment.

The efficacy of intravenous indomethacin in prevention of postoperative pain

Since intravenous prophylactic anti-inflammatory agents have been suggested to reduce or even replace opiates in postoperative pain therapy, we studied the demand for morphine in 45 patients recovering from abdominal surgery who had received a baseline infusion of either indomethacin, morphine or saline placebo. When extubated after inhalational anaesthesia, each patient received an i.v. bolus of either 0.5 mg.kg-1 indomethacin, 0.07 mg.kg-1 morphine or saline placebo. Thereafter a 20-h infusion of the same test analgesic was started, either 0.1 mg.kg-1.h-1 indomethacin, 0.03 mg.kg-1.h-1 morphine or saline placebo. For additional analgesia, a patient-controlled analgesia device (PCA) delivering 5-mg boluses of morphine was used. For the first 5 postoperative hours, significantly more (P less than 0.05) PCA morphine was needed in the indomethacin group (35 mg) than in the morphine group (24 mg), while the placebo group demanded mean 30 mg. For equal analgesia (measured by VAS and VRS) between 5-20 h, similar amounts (mean 23 and 19 mg) of PCA morphine were required in the indomethacin and morphine groups, in contrast to the placebo group (mean 40 mg) (P less than 0.001). Morphine infusion increased the total consumption of morphine by 25% as compared to placebo. We conclude that, following abdominal surgery, the analgesic effect of indomethacin infusion became apparent after the first 5 postoperative hours, thereafter reducing the demand for PCA morphine by about 40%. Continuous morphine infusion diminishes the postoperative demand for PCA morphine, but also increases the total morphine consumption.

Cardiovascular function and serum catecholamine concentrations after anesthesia and surgery in the dog

Peripheral vasoconstriction and plasma catecholamine concentrations were studied in 37 dogs after cervical disc fenestration and salivary gland excision, laparotomy for intestinal anastomoses and cystotomy, or laparotomy for repair of diaphragmatic rupture, gastrotomy, and pyloromyotomy. Meperidine (4.4 mg/kg) was administered before extubation of 12 dogs undergoing laparotomy. Heart rate, respiratory frequency, indirect blood pressure, rectal temperature, toe web temperature, and plasma concentrations of epinephrine and norepinephrine were determined before induction of anesthesia, after intubation, after extubation, at sternal recumbency, and at standing. All dogs were hypothermic during surgery. After surgery, peripheral hypothermia (large rectal-toe web temperature gradients) increased from a mean of 4.6 degrees C after intubation to a mean of 10.4 degrees C when the dogs initially stood. Heart and respiratory rates and blood pressures during recovery were similar to those before anesthesia. Mean plasma catecholamine concentrations were neither significantly higher during recovery than before surgery nor were they increased in any surgical group, including the dogs not treated with meperidine. After anesthesia, 15% of the epinephrine and 12% of the norepinephrine samples were more than two standard deviations above the mean of the preanesthetic concentrations of all dogs. The ratio of all dogs with an epinephrine concentration more than two standard deviations above the mean of baseline epinephrine concentrations was greater at sternal recumbency than before anesthesia and the ratio of dogs with an increased epinephrine concentration at sternal recumbency was greater in the laparotomy dogs (9 of 24) than in the cervical surgery dogs (0 of 12).(ABSTRACT TRUNCATED AT 250 WORDS)

Intravenous indomethacin for postoperative pain. A double-blind study of ankle surgery

Intravenous indomethacin infusion (75 mg/10 h) for relief of pain after ankle surgery was compared with placebo in a double-blind study. Ninety-seven patients were operated on for a malleolar fracture or ruptured ligament of the ankle under single-dose spinal anesthesia. In the indomethacin group, 14 out of 49 patients were free from pain, 4/47 in the control group. Severe pain was experienced by 24/49 in the indomethacin group and by 41/47 in the control group. Supplementary intramuscular oxycodone was needed for 24 patients in the indomethacin group and for 41 control patients. In 1 patient, i.v. indomethacin administration caused serious arterial hypotension necessitating discontinuation of the medication. Intravenous indomethacin reduced the need of opiate for alleviation of postoperative pain, but the possibility of hypersensitivity reaction calls for particular attention.