Acute renal failure associated with intramuscular ketorolac

Local infiltration analgesia: a technique for the control of acute postoperative pain following knee and hip surgery: a case study of 325 patients

BACKGROUND

We have developed a multimodal technique for the control of pain following knee and hip surgery, called "local infiltration analgesia" (LIA). It is based on systematic infiltration of a mixture of ropiva-caine, ketorolac, and adrenaline into the tissues around the surgical field to achieve satisfactory pain control with little physiological disturbance. The technique allows virtually immediate mobilization and earlier discharge from hospital.

PATIENTS AND METHODS

In this open, nonrandomized case series, we used LIA to manage postoperative pain in all 325 patients presenting to our service from Jan 1, 2005 to Dec 31,2006 for elective hip resurfacing (HRA), primary total hip replacement (THR), or primary total knee replacement arthroplasty (TKR). We recorded pain scores, mobilization times, and morphine usage for the entire group.

RESULTS

Pain control was generally satisfactory (numerical rating scale pain score range 0-3). No morphine was required for postoperative pain control in two-thirds of the patients. Most patients were able to walk with assistance between 5 and 6 h after surgery and independent mobility was achieved 13-22 h after surgery. Orthostatic hypotension, nausea, and vomiting were occasionally associated with standing for the first time, but other side effects were unremarkable. 230 (71%) of the 325 patients were discharged directly home after a single overnight stay in hospital.

INTERPRETATION

Local infiltration analgesia is simple, practical, safe, and effective for pain management after knee and hip surgery.

Effects of nonsteroidal anti-inflammatory drugs on postoperative renal function in adults with normal renal function

BACKGROUND

Nonsteroidal anti-inflammatory drugs (NSAIDs) can play a major role in the management of acute pain in the peri-operative period. However, there are conflicting views on whether NSAIDs are associated with adverse renal effects.

OBJECTIVES

The primary objective of this review was to determine the effects of NSAIDs on postoperative renal function in adults with normal preoperative renal function.

SEARCH STRATEGY

Electronic searches for relevant randomised and quasi-randomised controlled trials in Cochrane Central Register of Controlled Trials, MEDLINE and EMBASE were performed. Attempts were also made to identify trials from citation lists of relevant trials, review articles and clinical practice guidelines. Handsearching of conference abstracts published in major anaesthetic journals was also performed. Date of most recent search: May 2006

SELECTION CRITERIA

The inclusion criteria were randomised or quasi-randomised comparisons of individual NSAIDs with either each other or placebo for treatment of postoperative pain, with relevant postoperative renal outcome measures, in adult surgical patients with normal renal function.

DATA COLLECTION AND ANALYSIS

The data were extracted independently by two authors. The primary outcome measure was creatinine clearance within the first two days after surgery. Secondary outcome measures included serum creatinine, urine volume, urinary sodium level, urinary potassium level, fractional excretion of sodium, fractional excretion of potassium and need for dialysis. Weighted mean differences for continuous outcomes and relative risk (RR) and risk difference (RD) for dichotomous outcomes were estimated with 95% confidence intervals (CI).

MAIN RESULTS

Twenty-three trials (1459 patients) fulfilled the selection criteria for this review. NSAIDs reduced creatinine clearance by 16 mL/min (95%CI 5 to 28) and potassium output by 38 mmol/day (95%CI 19 to 56) on the first day after surgery compared to placebo. There was no significant difference in serum creatinine on the first day (0 umol/L, 95%CI -3 to 4) compared to placebo. No significant reduction in urine volume during the early postoperative period was found. There was no significant difference in serum creatinine in the early postoperative period between patients receiving diclofenac, ketorolac, indomethacin, ketoprofen or etodolac. No cases of postoperative renal failure requiring dialysis were described. The trials were not heterogeneous for the primary outcome.

AUTHORS' CONCLUSIONS

NSAIDs caused a clinically unimportant transient reduction in renal function in the early postoperative period in patients with normal preoperative renal function. NSAIDs should not be withheld from adults with normal preoperative renal function because of concerns about postoperative renal impairment.

A double-blind prospective comparison of rofecoxib vs ketorolac in reducing postoperative pain after arthroscopic knee surgery

STUDY OBJECTIVE

The aim of this study was to compare the analgesic efficacy of premedication with rofecoxib vs intravenous (IV) ketorolac in reducing postoperative pain after arthroscopic knee surgery.

STUDY DESIGN

This is a prospective, randomized, double-blinded study.

SETTING

This study was set at a university hospital.

SUBJECTS

The subjects include 54 patients with American Society of Anesthesiologists physical statuses I, II, and III undergoing knee arthroscopy.

INTERVENTIONS

Group 1 received 50 mg oral rofecoxib preoperatively with IV placebo injection, which was administered 20 minutes before the end of the operation. Group 2 received a preoperative placebo and 30 mg IV ketorolac 20 minutes before the end of surgery.

MEASUREMENTS

The primary outcome measure was the proportion of patients reporting pain in the postoperative anesthesia care unit, 6 hours and 24 hours after discharge. Additional end points included the use of 5:325 mg oxycodone-acetaminophen (O/A) tablets, pain scores, patient's satisfaction survey, and comparison of side effects. Data were analyzed using independent samples t tests for continuous variables or chi2 tests for categorical variables. P < .05 was considered significant.

RESULTS

The 2 groups were comparable with regard to patient characteristics, intraoperative medication use, and duration of surgery. There was no difference either in pain scores or O/A use in the postoperative anesthesia care unit. At 24 hours after discharge, significantly more patients in the ketorolac group (91%) reported pain than the rofecoxib group (63%) (P = .02). Sixty-one percent of patients in the ketorolac group used O/A during the first 24 hours vs 38% in the rofecoxib group. The difference, however, was not statistically significant.

CONCLUSION

Preoperative rofecoxib is as effective as ketorolac for the treatment of pain after knee arthroscopy. Higher frequency of pain reporting at 24 hours by patients in ketorolac group is explained by the longer analgesic effect of rofecoxib. Future studies should directly compare gastrointestinal injury of these drugs, as well as cost-effectiveness of rofecoxib vs ketorolac.

Effects of nonsteroidal anti-inflammatory drugs on postoperative renal function in adults with normal renal function

BACKGROUND

Nonsteroidal anti-inflammatory drugs (NSAIDs) can play a major role in the management of acute pain in the peri-operative period. However, there are conflicting views on whether NSAIDs are associated with adverse renal effects.

OBJECTIVES

The primary objective of this review was to determine the effects of NSAIDs on postoperative renal function in adults with normal preoperative renal function.

SEARCH STRATEGY

Electronic searches for relevant randomised and quasi-randomised controlled trials in Cochrane Central Register of Controlled Trials, MEDLINE and EMBASE were performed. Attempts were also made to identify trials from citation lists of relevant trials, review articles and clinical practice guidelines. Handsearching of conference abstracts published in major anaesthetic journals was also performed. (Search date: 7 February 2003)

SELECTION CRITERIA

The inclusion criteria were randomised or quasi-randomised comparisons of individual NSAIDs with either each other or placebo for treatment of postoperative pain, with relevant postoperative renal outcome measures, in adult surgical patients with normal renal function.

DATA COLLECTION AND ANALYSIS

The data was extracted independently by two reviewers. The primary outcome measure was creatinine clearance within the first two days after surgery. Secondary outcome measures included serum creatinine, urine volume, urinary sodium level, urinary potassium level, fractional excretion of sodium, fractional excretion of potassium, need for dialysis and need for diuretic or dopamine treatment for renal insufficiency. Weighted mean differences for continuous outcomes and relative risk for dichotomous outcomes were estimated.

MAIN RESULTS

Nineteen trials ( n = 1204) fulfilled the selection criteria for this review. NSAIDs reduced creatinine clearance by 16 ml/min (95%CI 5 to 28) and potassium output by 38 mmol/day (95%CI 19 to 56) on the first day after surgery compared to placebo. There was no significant difference in serum creatinine on the first day (0 umol/L, 95%CI -5 to 4) compared to placebo. No significant reduction in urine volume during the early postoperative period was found. There was no significant difference in serum creatinine in the early postoperative period between patients receiving diclofenace and ketorolac (or indomethacin). No cases of postoperative renal failure requiring dialysis were described. The trials were homogeneous for the primary outcome.

REVIEWERS' CONCLUSIONS

NSAIDs caused a clinically unimportant transient reduction in renal function in the early postoperative period in patients with normal preoperative renal function. NSAIDs should not be withheld from adults with normal preoperative renal function because of concerns about postoperative renal impairment.

Effect of celecoxib and dexamethasone on postoperative pain after lumbar disc surgery

OBJECTIVE

This study was designed to assess the efficacy of perioperative administration of celecoxib (Celebrex; Pharmacia GmbH, Erlangen, Germany) in reducing pain and opioid requirements after single-level lumbar microdiscectomy.

METHODS

We studied 34 patients (mean age, 44.26 yr; standard deviation [SD], 13.09 yr) allocated randomly to receive celecoxib 200 mg twice a day for 72 hours starting on the evening before surgery or placebo capsules in a double-blind study. Fourteen patients received 20 to 80 mg dexamethasone intravenously during surgery (mean, 40 mg; SD, 19.22 mg) because of visible signs of compression of the affected nerve root. After lumbar disc surgery, patients were monitored for visual analog scores for pain at rest and on movement, patient-controlled analgesia (PCA) piritramide requirements, and von Frey thresholds in the wound area.

RESULTS

Pain scores decreased and wound von Frey thresholds increased continuously until discharge, with no intergroup differences. Mean 24-hour PCA piritramide requirements were 22.63 mg (SD, 23.72 mg) and 26.14 mg (SD, 22.57 mg) in the celecoxib and placebo groups, respectively (P = not significant). However, patients with intraoperative dexamethasone (n = 14) required only 10.29 mg (SD, 8.55 mg) 24-hour PCA piritramide, in contrast to the 34.25 mg (SD, 24.69 mg) needed in those who did not receive intraoperative dexamethasone (P = 0.001). In addition, 24 hours after the operation, pain scores on movement were significantly lower in the dexamethasone subgroup (P = 0.003).

CONCLUSION

Celecoxib has no effect on postoperative pain scores and PCA piritramide requirements. The intraoperative use of 20 to 80 mg dexamethasone is able to significantly decrease postoperative piritramide consumption and pain scores on the first day after surgery.

Intraoperative ketorolac and eye pain after viteoretinal surgery: a prospective, randomized, placebo-controlled study

PURPOSE

To compare the efficacy of one intraoperative dose of intravenous ketorolac tromethamine to saline placebo in controlling postoperative eye pain, nausea, and sedation following vitreoretinal surgery.

STUDY DESIGN

Prospective, randomized, placebo-controlled clinical trial.

METHODS

One hundred fourteen vitreoretinal surgical patients were randomized over a 7-month period to a single intraoperative intravenous dose of ketorolac tromethamine or placebo. All patients underwent surgery with intravenous sedation and retrobulbar anesthetic injection and had access to a standard postoperative analgesic regimen. After 2 and 5 hours, eye pain, nausea, and sedation levels were recorded using a standard visual analog scale. Analgesic requirements were tabulated.

RESULTS

Patients given ketorolac were significantly less likely to have postoperative eye pain than were placebo-treated patients (P = 0.0043). Fewer ketorolac patients required postoperative analgesia than placebo patients did (P < 0.0001). Four ketorolac patients (7%) required a narcotic compared to 11 placebo patients (20%) (P < 0.0001). Fewer ketorolac patients experienced nausea and sedation than placebo patients did, but this difference was not statistically significant.

CONCLUSION

Ketorolac tromethamine is an effective nonnarcotic choice for postoperative pain control following vitreoretinal surgery. Pain control is particularly important in this group of patients, whose compliance with postoperative procedures and positioning may significantly affect surgical outcome.

Evaluation of preoperative administration of the cyclooxygenase-2 inhibitor rofecoxib for the treatment of postoperative pain after lumbar disc surgery

OBJECTIVE

A combination of analgesics with different mechanisms of action may improve postoperative pain control and reduce the incidence of side effects. This study was designed to assess the efficacy of preoperative administration of rofecoxib (Vioxx; Merck & Co., Inc., Somerset, NJ) in reducing pain and opioid requirements after single-level lumbar microdiscectomy.

METHODS

A randomized, double-blind, placebo-controlled clinical trial was performed on 61 consenting patients who were considered American Society of Anesthesiologists Class I or II and who were scheduled for elective single-level lumbar microdiscectomy. Patients received either two doses of rofecoxib 50 mg or a placebo preoperatively. The outcome measures included morphine use in the postanesthesia care unit (PACU), discharge times, and side effect profile. Data were analyzed by use of independent sample t tests for continuous variables or chi(2) tests for categorical variables. A P value of <0.05 was considered significant.

RESULTS

The two groups were comparable with respect to patient characteristics, intraoperative opioid and hypnotic consumption, and duration of surgery. Patients in the rofecoxib group required significantly less morphine postoperatively. Significantly more patients in the placebo group reported pain scores greater than 7 at admission to the PACU. Time to first request for analgesia was shorter in the placebo group, but the difference did not reach statistical significance. There were no significant differences between groups in the incidence of nausea, time to discharge from the PACU, or hospital stay.

CONCLUSION

Preoperative rofecoxib is effective in reducing postoperative narcotic consumption in patients undergoing lumbar laminectomy. The use of rofecoxib does not shorten PACU length of stay or hospital discharge time. These outcome measures depend on multiple administrative factors.

Postoperative narcotic requirement after microscopic lumbar discectomy is not affected by intraoperative ketorolac or bupivacaine

STUDY DESIGN

Prospective, randomized, double-blind study.

OBJECTIVE

To assess the efficacy of ketorolac and bupivacaine in reducing postoperative pain after microsurgical lumbar discectomy.

SUMMARY OF BACKGROUND DATA

Microsurgical lumbar discectomy often is performed as an ambulatory procedure. Pain, nausea, and urinary retention may delay discharge. It was hypothesized that intraoperative ketorolac or bupivacaine would reduce postoperative pain as measured by morphine demand.

METHODS

After Institutional Review Board (IRB) approval and informed consent, 30 patients undergoing single-level microsurgical lumbar discectomy under general anesthesia randomly received either intravenous ketorolac, intramuscular bupivacaine, or placebo before wound closure. After surgery, all patients received intravenous, MSO4, patient-controlled analgesia. MSO4 demand was compared between groups at 30 minutes and at 1, 4, 8, 16, 20, and 24 hours after surgery by one-way ANOVA. Pre- and postoperative pain was assessed by using a standard scale and was correlated to postoperative MSO4 demand by Pearson correlation. Significance was assumed at P < 0.05.

RESULTS

There were no group differences in age, gender, weight, disc level, preoperative pain, or preoperative use of pain medication. Neither ketorolac nor bupivacaine decreased pain or nausea scores, MSO4 demand, or time to void and ambulation. Preoperative pain was significantly correlated to postoperative narcotic demand (r = 0.46, P < 0.01). Preoperative narcotic or NSAID use was not correlated to either preoperative pain scores or postoperative MSO4 requirement.

CONCLUSIONS

Neither ketorolac nor bupivacaine decreased the postoperative narcotic requirement in patients undergoing microsurgical lumbar discectomy. Postoperative narcotic requirements are increased in patients who are in severe pain before surgery, regardless of preoperative narcotic use.

The effects of nonsteroidal anti-inflammatory drugs (NSAIDs) on postoperative renal function: a meta-analysis

The aim of this systematic review was to assess the effects of nonsteroidal anti-inflammatory drugs (NSAIDs) on post-operative renal function. Eight randomized placebo-controlled double-blinded trials (n = 345) were identified from searches of MEDLINE, EMBASE and the Cochrane Controlled Trials Register databases. The summary effect size and 95% confidence intervals (95% CI) were calculated by a weighted mean difference analysis using a random-effects model. The NSAIDs (diclofenac, ketorolac, indomethacin, ibuprofen) were used for up to three-days after surgery. There were no reported cases of postoperative renal failure requiring dialysis. NSAIDs reduced creatinine clearance by 22 ml.min-1 (95% CI: 7 to 37), sodium output by 54 mmol.day-1 (95% CI: 5 to 103) and potassium output by 38 mmol.day-1 (95% CI: 19 to 56) on Day 1 but not on Day 2. Serum creatinine increased on Day 2 by 15 mumol.l-1 (95% CI: 2 to 28). Urine volume did not change significantly at any time. There was therefore a clinically unimportant transient reduction in renal function. NSAIDs should not be withheld from patients with normal preoperative renal function because of concerns about postoperative renal impairment.

Factors influencing ketorolac-associated perioperative renal dysfunction

Nonsteroidal antiinflammatory drugs (NSAIDs) are useful for the treatment of postoperative pain, but there is continuing concern about adverse effects on renal function. We studied the renal effects of ketorolac in an animal model using Fischer 344 rats undergoing isoflurane anesthesia and laparotomy. Treatment groups--control (C), ketorolac (5 mg x kg(-1) x d(-1)) (K), large-dose ketorolac (15 mg x kg(-1) x d(-1)) (KH), dehydration-ketorolac (5 mg x kg(-1) x d(-1)) (DK), gentamicin (20 mg x kg(-1) x d(-1)) (G), and gentamicin (20 mg x kg(-1) x d(-1)) with ketorolac (5 mg x kg(-1) x d(-1)) (GK)--each comprised 10 animals. Renal function was assessed before laparotomy and after 3 treatment days using concurrent paraaminohippurate and iothalamate clearances, respectively, to estimate renal plasma flow and glomerular filtration rate, and by measuring serum and urine electrolytes, osmolality, urea, and creatinine. A significant increase in serum potassium was found in the GK and DK groups. There were no major changes in renal function in the C, K, KH, and DK groups. Mild renal dysfunction was found in the G group. We found severe and consistent changes in renal function, accompanied by severe, widespread histological changes of acute tubular necrosis, in the GK group. In this postoperative rat model, the combination of ketorolac and gentamicin was deleterious to renal function.

IMPLICATIONS

We examined the renal effects of the nonsteroidal antiinflammatory drug ketorolac. Renal function was measured in rats before and after surgery and 3 days' drug administration; the kidneys studied by using microscopy. Only ketorolac plus the antibiotic gentamicin produced marked changes in kidney function and structure.

Ketorolac. A reappraisal of its pharmacodynamic and pharmacokinetic properties and therapeutic use in pain management

Ketorolac is a nonsteroidal anti-inflammatory drug (NSAID) with strong analgesic activity. The analgesic efficacy of ketorolac has been extensively evaluated in the postoperative setting, in both hospital inpatients and outpatients, and in patients with various other acute pain states. After major abdominal, orthopaedic or gynaecological surgery or ambulatory laparoscopic or gynaecological procedures, ketorolac provides relief from mild to severe pain in the majority of patients and has similar analgesic efficacy to that of standard dosages of morphine and pethidine (meperidine) as well as less frequently used opioids and other NSAIDs. The analgesic effect of ketorolac may be slightly delayed but often persists for longer than that of opioids. Combined therapy with ketorolac and an opioid results in a 25 to 50% reduction in opioid requirements, and in some patients this is accompanied by a concomitant decrease in opioid-induced adverse events, more rapid return to normal gastrointestinal function and shorter stay in hospital. In children undergoing myringotomy, hernia repair, tonsillectomy, or other surgery associated with mild to moderate pain, ketorolac provides comparable analgesia to morphine, pethidine or paracetamol (acetaminophen). In the emergency department, ketorolac attenuates moderate to severe pain in patients with renal colic, migraine headache, musculoskeletal pain or sickle cell crisis and is usually as effective as frequently used opioids, such as morphine and pethidine, and other NSAIDs and analgesics. Subcutaneous administration of ketorolac reduces pain in patients with cancer and seems particularly beneficial in pain resulting from bone metastases. The acquisition cost of ketorolac is greater than that of morphine or pethidine; however, in a small number of studies, the higher cost of ketorolac was offset when treatment with ketorolac resulted in a reduced hospital stay compared with alternative opioid therapy. The tolerability profile of ketorolac parallels that of other NSAIDs; most clinically important adverse events affect the gastrointestinal tract and/or renal or haematological function. The incidence of serious or fatal adverse events reported with ketorolac has decreased since revision of dosage guidelines. Results from a large retrospective postmarketing surveillance study in more than 20,000 patients demonstrated that the overall risk of gastrointestinal or operative site bleeding related to parenteral ketorolac therapy was only slightly higher than with opioids. However, the risk increased markedly when high dosages were used for more than 5 days, especially in the elderly. Acute renal failure may occur after treatment with ketorolac but is usually reversible on drug discontinuation. In common with other NSAIDs, ketorolac has also been implicated in allergic or hypersensitivity reactions. In summary, ketorolac is a strong analgesic with a tolerability profile which resembles that of other NSAIDs. When used in accordance with current dosage guidelines, this drug provides a useful alternative, or adjuvant, to opioids in patients with moderate to severe pain.

Renal papillary necrosis following emergency department treatment of migraine

New medications have lessened the need for narcotic medications in the acute treatment of migraine. Some of these new medications include parenteral dihydroergotamine (DHE), sumatriptan, and ketorolac. Treatment failures still occur, though, and some cases necessitate adding a second agent to one that has been ineffective. We report a case of a 46-year-old man who suffered renal papillary necrosis 12 days after receiving parenteral DHE, sumatriptan, and ketorolac for treatment of a severe migraine headache. There were no signs of an adverse drug reaction at the time of his emergency department visit. The case illustrates a potential hazard of this combination in the acute treatment of migraine.

A comparison of the efficacy of ketorolac and indomethacin for postoperative analgesia following laparoscopic surgery in day patients

The analgesia provided in the postoperative period by three regimens commonly used in our private anaesthetic practice were compared in a double-blind study of one hundred and thirty-seven women presenting for day-case laparoscopic procedures. After random allocation into three groups, all patients were similarly anaesthetized and then received both a rectal suppository and an IM injection. Group P received two placebos, Group I had an indomethacin suppository 100 mg and Group K an IM injection of ketorolac 30 mg. The trial showed a statistically significant reduction in pain at 180 minutes postoperatively in the group receiving ketorolac (visual analog pain score of 13.8 v 21.7). The parenterally administered ketorolac may be a useful analgesic supplement in these patients. However the trial was aborted following the appearance in the literature of case reports of postoperative renal failure. Further investigation of the efficacy and side-effect profile of reduced doses may be warranted.

Ketorolac or pethidine for analgesia after elective laparoscopic sterilization

Laparoscopic sterilization is commonly performed as a day surgery procedure despite difficulties in providing adequate postoperative analgesia for all patients. We have examined the analgesic utility of intramuscular ketorolac in this setting by comparing it with intramuscular pethidine, both given after induction in a randomized, double-blind study in sixty such patients. Although the analgesic effects of the two drugs were comparable in the immediate postoperative period, ketorolac provided significantly better analgesia four hours after surgery (pain score of 2.7 v. 4.2, P = 0.006). The recovery times taken to awake, to ambulate and for discharge were all significantly shorter after ketorolac (4.6 v. 8.8 min, P = 0.01; 178 v. 260 min, P = 0.0005; 242 v. 320 min, P = 0.02), and the unplanned admission rate was also significantly less after ketorolac (7% v. 33%, P = 0.01). Ketorolac appears to be a useful supplement for analgesia after laparoscopic sterilization, providing improved analgesia as well as decreased recovery time and fewer unplanned admissions.

Nonsteroidal anti-inflammatory drugs in perisurgical pain management. Mechanisms of action and rationale for optimum use

Nonsteroidal anti-inflammatory drugs (NSAIDs) are a group of agents with similar actions but diverse chemical structures. Aspirin (acetylsalicylic acid) and sodium salicylate were the first drugs of this type to be used clinically. However, over the past 3 decades there has been a dramatic increase in the number of NSAIDs available for the treatment of postoperative pain. Tissue injury, such as occurs with surgical intervention, is associated with the release of numerous inflammatory mediators including prostaglandins. Prostaglandins derived from the arachidonic acid cascade are implicated in the production of inflammatory pain, and in sensitising nociceptors to the actions of other mediators. They are synthesised from arachidonic acid via the endoperoxide biosynthesis pathway, the initial step of which is catalysed by the enzyme cyclo-oxygenase. Two forms of the cyclo-oxygenase enzyme (COX-1 and COX-2) have been characterised. COX-1 is important in circumstances where prostaglandins have a protective effect such as gastric mucus production and renal blood flow maintenance. NSAIDs inhibit the synthesis of prostaglandins at 1 or more points in the endoperoxide pathway. Three mechanisms of inhibition of the biosynthetic enzymes have been proposed: (i) rapid, reversible competitive inhibition; (ii) irreversible, time-dependent inhibition; and (iii) rapid, reversible noncompetitive (free radical trapping) inhibition. In addition, there is evidence that NSAIDs have a central antinociceptive mechanism of action that augments the peripheral effect. This may involve inhibition of central nervous system prostaglandins or inhibition of excitatory amino acids or bradykinins. There is considerable variability in the pain relief obtained from NSAIDs. Such variability in drug response may be explained in terms of differences between agents with respect to either pharmacodynamic actions or pharmacokinetic parameters or a combination of both. Stereoisomerism, where preparations exist as racemic mixtures and where only 1 enantiomer is active, may also be important. However, chiral inversion from inactive to active enantiomer may occur and may be rapid or slow. NSAIDs have numerous adverse effects. Gastrointestinal disturbances including ulceration are the commonest adverse responses to NSAIDs and carry the greatest risk of death. Also significant are renal impairment and an increased risk of postoperative haemorrhage. Asthma and allergic reactions are uncommon.(ABSTRACT TRUNCATED AT 400 WORDS)

The general versus regional anaesthesia debate: time to re-examine the goals

New justification for the use of regional anaesthesia, either alone or in combination with general anaesthesia, has been provided with reports of some unexpected influences on outcome. A reduction in the incidence of postoperative thrombotic episodes and vascular graft occlusion is strongly suggested in patients with generalized vascular disease. Application of a variety of drugs, including local anaesthetics, opioids and adrenergic agonists, in the region of the spinal cord reduces afferent input during surgery and also the metabolic stress response. Evidence is increasing that this multi-modal approach to anaesthesia has important consequences in the spinal cord which result in modification of the postoperative requirement for analgesia. Premedication with opioid and other analgesics may also enhance this pre-emptive effect. New general anaesthetic and analgesic drugs are available that are more suited to these combined techniques. They have shorter duration of action so that plasma concentration can be rapidly adjusted to match a variable surgical stimulus.