The value of "multimodal" or "balanced analgesia" in postoperative pain treatment

Regional analgesia in the intensive care unit. Principles and practice

Nociception is a complicated process, and only in recent years have the neural pathways and mediators of pain transmission been unraveled. Several regional anesthetic interventions, most notably epidural drug delivery, can interrupt nociception and provide safe and effective pain control in critically ill patients while substantially reducing the need for systemic medications. This article discusses the possibilities for regional control of the neurobiology of nociception and describes the arsenal of regional anesthetic techniques available to the intensivist. Used wisely, regional techniques can provide excellent pain control and may have a significant role in improving overall patient outcome. Regional analgesia offers the best opportunity to provide substantial analgesia without significant central opioid effects. Well-conducted regional analgesia can reduce many of the unpleasant or potentially problematic side effects observed when traditional intravenous medications are used exclusively for pain control.

Goal oriented general anesthesia for Cesarean section in a parturient with a large intracranial epidermoid cyst

PURPOSE

To illustrate the anesthetic management of a term parturient with a large brain tumour scheduled for Cesarean section.

CLINICAL FEATURES

A 26-yr-old woman presented at 33 weeks gestation with a generalized grand mal seizure. Magnetic resonance imaging demonstrated a 5-cm multi-lobulated extra axial mass compatible with an epidermoid cyst, arising from the left temporal lobe associated with shift of the midline structures and compression of the brainstem. She remained stable neurologically until elective Cesarean section at 38 weeks. Immediately prior to induction of general anesthesia, the proposed incision site was infiltrated with lidocaine and the supraglottic structures anesthetized with bilateral superior laryngeal nerve blocks. Remifentanil, thiopentone sodium and succinylcholine were administered in a rapid sequence fashion following voluntary hyperventilation to an endtidal CO2 of 28 mmHg. Anesthesia was maintained with desflurane in oxygen/air and an infusion of remifentanil. Postoperative pain control was achieved using a multi-modal approach which included intraperitoneal deposition of local anesthetic, im ketorolac and rectal acetaminophen prior to emergence followed by regular administration of naproxen and acetaminophen for 72 hr.

CONCLUSION

In a parturient with a large intracranial tumour, general anesthesia combined with multi-modal balanced analgesia met the predefined anesthetic management goals and was associated with a favourable outcome.

Interscalene brachial plexus block with continuous intraarticular infusion of ropivacaine

Providing intraarticular analgesia with a continuous infusion of local anesthetic via a disposable infusion pump has gained popularity. Despite the prevalence of this technique, data comparing this method of analgesia to conventional regional anesthesia are not available. We present a prospective study that compared a single-dose interscalene block with a single-dose interscalene block plus continuous intraarticular infusion of local anesthetic. Forty patients scheduled for shoulder arthroscopy were entered in this prospective, double-blinded study. All patients received an interscalene brachial plexus block as their primary anesthetic. Patients were randomly assigned to 1 of 2 groups: 1. interscalene block with 1.5% mepivacaine (40 mL) followed by a postoperative intraarticular infusion of 0.5% ropivacaine at 2 mL/h, or 2. interscalene block with 0.5% ropivacaine (40 mL) followed by a postoperative intraarticular infusion of 0.9% saline (placebo) at 2 mL/h. Postoperative infusions were maintained for 48 h. Visual analog scale pain scores and postoperative oxycodone consumption were measured for 48 h. Visual analog scale scores at rest and with ambulation in the Mepivacaine/Intraarticular Ropivacaine group were reduced when compared with the Ropivacaine/Saline group (rest: P = 0.003, ambulation: P = 0.006). Oxycodone consumption was also decreased (28 +/- 21 mg vs 44 +/- 28 mg, P = 0.046), respectively. We conclude that a brachial plexus block with 1.5% mepivacaine and a continuous intraarticular infusion of 0.5% ropivacaine at 2 mL/h provides improved analgesia for minor surgery at 24 and 48 h versus a single-injection interscalene block with 0.5% ropivacaine.

Management of acute and postoperative pain

The optimal management of postoperative pain is a prerequisite for early recovery and shorter hospital stays. The use of multimodal analgesia techniques involving the use of opioid and non-opioid (local anesthetics, ketamine, acetaminophen, and non-steroidal anti-inflammatory drugs) analgesic drugs can markedly enhance pain relief in the perioperative period.

The analgesic efficacy of patient-controlled bupivacaine wound instillation after total abdominal hysterectomy with bilateral salpingo-oophorectomy

To assess the effect of local anesthetic wound instillation on visceral and somatic pain, we studied 36 patients undergoing total abdominal hysterectomy and bilateral salpingo-oophorectomy. A standard general anesthetic was administered. On completion of the operation, a multiorifice 20-gauge epidural catheter was placed above the superficial abdominal fascia such that the tip was at the midpoint of the surgical wound. After surgery, either bupivacaine 0.25% (Bupivacaine group) or sterile water (Control group) was administered via a patient-controlled analgesia device programmed to deliver 9.0 mL with a 60-min lockout interval. During the first 6 h after surgery, rescue IV morphine (2 mg) was administered every 10 min until a visual analog scale score of <30 mm was achieved. Thereafter, on patient request, rescue meperidine 1 mg/kg IM was administered. When compared with the Control group, significantly (P < 0.001) less rescue analgesia was administered to patients in the Bupivacaine group. Rescue morphine administered during the first 6 h after surgery was 6 +/- 4 mg versus 12 +/- 6 mg (P < 0.001) for the Bupivacaine and Control groups, respectively. Rescue meperidine administered was 29 +/- 37 mg versus 95 +/- 36 mg (P < 0.001) for the Bupivacaine and Control groups, respectively. Nausea and antiemetic drug administration was significantly (P = 0.003) less in the Bupivacaine group. Pain scores were similar between the groups. Patient satisfaction was significantly (P = 0.04) more in the Bupivacaine group. We conclude that bupivacaine wound instillation decreases opioid requirements and nausea in the first 24 h after total abdominal hysterectomy with bilateral salpingo-oophorectomy.

IMPLICATIONS

Bupivacaine instillation via an electronic patient-controlled analgesia device provides effective analgesia after total abdominal hysterectomy with bilateral salpingo-oophorectomy.

Epidural analgesia and risk of anastomotic leakage

BACKGROUND AND OBJECTIVES

Based on case reports of early anastomotic leakage in patients receiving epidural analgesia with local anesthetic and data to document a stimulatory effect of epidural block on gastrointestinal motility, it has been suggested that continuous infusion of epidural local anesthetic may lead to an increased incidence of anastomotic leakage. Therefore, we examined the association between continuous epidural local anesthetic and anastomotic leakage by reviewing the literature.

METHODS

Review of controlled, randomized clinical trials aiming to investigate postoperative complications in which continuous postoperative epidural local anesthetic was administered in patients scheduled for colorectal surgery with an anastomosis. Data were obtained from a Medline search (1966-May 2000), previous review articles, references cited in original papers, and personal communication with investigators. Twelve trials including a total of 562 patients met the inclusion criteria.

RESULTS

Sixteen of 266 patients (6.0%, 95% confidence interval [CI]: 3.5% to 9.6%) receiving postoperative epidural local anesthetic or epidural local anesthetic-opioid mixtures developed anastomotic leakage, compared with 10 of 296 patients (3.4%, 95% CI: 1.6% to 6.1%) receiving epidural or systemic opioid-based analgesia (P >.05 between groups, Fisher's test). The risk of overlooking a significant difference (type II error) was approximately 67% (power: 33%). Studies including more than 1,037 patients in each group are needed to demonstrate an increased risk of anastomotic leakage from 3.4% to 6.0% with 80% power and 2alpha = 0.05. There was no significant difference (P >.05 between groups, Fisher's test) between subgroups of study design: Epidural local anesthetic-versus systemic or epidural opioid, or epidural local anesthetic-opioid mixtures versus systemic or epidural opioid.

CONCLUSIONS

So far, there is no statistically significant evidence from randomized trials to indicate epidural analgesia with local anesthetic to be associated with an increased risk of anastomotic breakdown. However, relatively few patients have been included in randomized trials, indicating a need for more studies to secure valid conclusions.

Determinant factors of pain after ambulatory inguinal herniorrhaphy: a multi-variate analysis

Pain is common after inguinal herniorrhaphy. The objective of our study was to evaluate the significance of various clinical factors on the level of post-operative pain after ambulatory inguinal herniorrhaphy. Between January, 1996 and December, 1998, 239 ambulatory inguinal hernia repair patients were recruited. Operative techniques included nylon darn (n = 152), modified Bassini repair (n = 56), and prolene mesh hernioplasty (n = 30). Linear analogue pain scores--ranging in value from 0 to 10--were assessed by telephone interviews on the first and third post-operative days. Uni-variate and multi-variate analyses were performed to identify the significant independent determinant factors affecting the severity of post-operative pain. Clinical factors studied were age, sex, operative technique, hernia anatomy and post-operative complication(s). By uni-variate analysis, patients of age < or = 50 years and indirect inguinal hernia were associated with a significantly higher pain score on the first postoperative day 1. On post-operative day 3, patients of age < or = 50 years, with an indirect inguinal hernia and modified Bassini repair reported a significantly higher pain score. Following inguinal herniorrhaphy, multiple regression analysis showed that age was the only independent predictive factor of pain score on post-operative days 1 and 3. In conclusion, post-operative pain was not affected by surgical technique, sex, hernia anatomy and post-operative morbidity. Only age had a significant influence on the post-operative pain score following ambulatory inguinal herniorrhaphy. Therefore, the age of a patient should be taken into consideration when prescribing post-operative analgesics.

[Periodic evaluation of practices in postoperative pain management]

OBJECTIVE

Periodical assessment of practices as part of a quality assurance program: impact on postoperative pain.

PATIENTS

All patients evaluated from the first postoperative day during a week.

METHODS

Two surveys performed at a six month interval after establishment of some corrective measures. Different items were evaluated: pre-anaesthesia information for patients, pain severity and satisfaction with pain treatment. Medical data were consulted concerning postoperative analgesic prescriptions, their realization, pain assessment by nurses. Between the two surveys, first survey results were presented to anaesthesiologists. Then guidelines for prescriptions were suggested and new monitoring guidelines were proposed to nurses in surgical ward.

RESULTS

94 patients were evaluated during each survey. Patients had undergone orthopaedic, visceral, urology, ophthalmology and vascular surgery. Half of the patients did not receive information about pain before surgery. 43% of patients had a pain scores = 30/100 during movements; no difference was found between the two evaluations. Satisfaction graded as "moderate or insufficient" decreased from 22% (1rst survey) to 10 (2nd survey) (p < 0.05). Non steroidal anti-inflammatory drugs and nefopam prescriptions increased between the two surveys (p < 0.05). Association of three or four analgesics increased between the two surveys and monotherapies decreased (p < 0.05). Concordance of prescriptions with guidelines was 55% during first survey and 62% during the second (NS). Pain severity was not recorded for 36% of patients at first survey and in 18% at the second (p < 0.05).

CONCLUSION

Although anaesthesiologists and nurses changed their practice due to a quality insurance program concerning postoperative pain, its consequence on the severity of postoperative pain was not significant.

The analgesic efficacy of patient-controlled ropivacaine instillation after Cesarean delivery

To assess the efficacy and safety of wound instillation of ropivacaine, when administered via a patient-controlled elastometric pump, 50 term parturients undergoing cesarean delivery were enrolled into this prospective, placebo-controlled, double-blinded study. In all cases, a standard spinal anesthetic was administered. After the surgery, a multihole 20-gauge epidural catheter (B. Braun, Melsungen, Germany) was placed above the fascia such that the tip was sited at the point that demarcated 50% of the length of the surgical wound. Thereafter, the catheter was connected to the elastometric pump. According to a computer-generated randomization schedule, the pump was filled with either ropivacaine 0.2% (Ropivacaine Group) or an equal volume of sterile water (Control Group). Postoperatively, patient-controlled analgesia was administered via the elastometric pump. During the first 6 postoperative hours, a coinvestigator administered "rescue" morphine (2 mg, IV). Thereafter, "rescue" dipyrone (1 g) was administered on patient request. In a subset of 10 patients, blood ropivacaine levels were assessed. Compared with the Control Group, significantly fewer patients in the Ropivacaine Group received "rescue" morphine (92% vs. 48%, respectively) (P<0.01). The total "rescue" morphine administered during the first 6 postoperative hours was 2+/-3 mg vs. 10+/-5 mg (P<0.01) for the Ropivacaine and Control Groups, respectively. Patient-generated resting pain scores were similar between the groups. However, pain scores generated after coughing and leg raise were significantly (P<0.04) less in the Ropivacaine Group. More patients in the Ropivacaine Group than in the Control Group described their analgesia as good or excellent. In the subset of patients (n = 10) studied, unbound ropivacaine blood levels were below the toxic threshold (600 ng/mL). However, blood ropivacaine accumulation was noted. All patients stated that the elastometric pump was easy to use. Ropivacaine wound instillation via an elastometric pump is a simple technique that provides safe and effective analgesia after cesarean delivery.

[Postoperative pain and surgical treatment of trapeziometacarpal osteoarthritis of the thumb after ambulatory surgery]

OBJECTIVE

The course of pain and the incidence of the side effects from analgesics were evaluated for 15 days in 26 consecutive outpatients who underwent a surgical cure of trapeziometacarpal osteoarthritis of the thumb under regional block.

STUDY DESIGN

Prospective study.

METHODS

The analgesic regimen prescribed at discharge consisted on a regular administration of a combination of ketoprofen (50 mg.6.h-1) plus the association of acetaminophen and propoxyphene (two tablets.6.h-1). Patients were asked to evaluate their pain using a numerical rating scale graduated from 0 to 10. Data were collected during a telephone interview at day 4, 8 and 15.

RESULTS

Overall, patients scrupulously followed the medical prescription. At day four, 80% of patients still needed analgesics. The mean period during which NSAID, acetaminophen and propoxyphene were maintained was 4 and 6 days respectively. Fifty percent of patients reported severe pain during postoperative day 1 and 2. Moderate pain was reported at day 3 and 4 in respectively 54% and 42% of cases. Beyond this period, most patients indicated pain of weak intensity (71% at day 8). Epigastric pain has been noticed for 27% of patients.

CONCLUSION

The surgical correction of trapeziometacarpal osteoarthritis of the thumb is frequently performed according to an ambulatory setting. The fact that 50% of patients reported severe pain during the early postoperative period emphasize the inadequacy of our postoperative pain management for this surgical procedure.

The pharmacological basis of contemporary pain management

Pain management has become an increasingly well researched area in medicine over recent years, and there have been advances in a number of areas. While opioids remain an integral part of pain-management strategies, there is now an emphasis on the use of adjuvant drugs, such as paracetamol and anti-inflammatory agents, which through physiological or pharmacological synergism, both enhance pain control and reduce opioid use. The management of neuropathic pain continues to be a challenge. Anti-epileptics and antidepressants, together with clonidine and ketamine, provide the foundations for treatment. Another area of interest has been the widespread use of patient-controlled analgesia and the administration of some drugs, especially opioids, by means other than traditional oral and parenteral routes. The number of new drugs that have reached the stage of clinical trials has been small, yet they offer exciting possibilities. The epibatidine analogue ABT-594 and zinconitide both offer novel approaches to the management of neuropathic pain states, while selective cyclo-oxygenase-2 inhibitors and nitroaspirins may see advances in the management of nociceptive pain states.

Continuous intravenous diclofenac does not induce opioid-sparing or improve analgesia in geriatric patients undergoing major orthopedic surgery

STUDY OBJECTIVE

To assess the analgesic efficacy and perioperative opioid-sparing effects of adjuvant intravenous (IV) diclofenac.

DESIGN

Prospective, controlled, double-blind study.

SETTING

Large referral hospital.

PATIENTS

40 ASA physical status I, II, and III geriatric patients (>65 years) undergoing open reduction and internal fixation of subcapital fracture of the femur.

INTERVENTIONS

A standardized general anesthetic was administered. On induction of anesthesia, patients in the diclofenac group received an IV bolus of diclofenac (0.7 mg/kg) followed by a constant infusion (0.15 mg/kg/hr) until the end of surgery. In the saline group, an equal volume of saline was administered. "Rescue" fentanyl was administered in response to an increase in mean arterial pressure or heart rate (exceeding 20% of the patient's preinduction "baseline" values) that did not respond to a 30% increase in the inspired isoflurane concentration. Postoperative pain was assessed using a four-point patient-generated pain score (1 = none, 2 = mild, 3 = moderate, 4 = severe) as well as number of attempts and actual morphine delivered via a patient-controlled analgesia (PCA) device.

MEASUREMENTS AND MAIN RESULTS

The two treatment groups were demographically comparable. The perioperative hemodynamic variables, as well as the induction and "rescue" fentanyl dosages, were unaffected by the treatment modality. Pain scores, PCA attempts, and actual morphine delivered were statistically similar between the two groups.

CONCLUSIONS

Adjuvant IV diclofenac does not improve intraoperative stability or decrease postoperative opioid requirements in geriatric patients undergoing internal fixation of subcapital fracture of the femur.

Postoperative analgesic effects of celecoxib or rofecoxib after spinal fusion surgery

Nonsteroidal antiinflammatory drugs are recommended for the multimodal management of postoperative pain and may have a significant opioid-sparing effect after major surgery. The analgesic efficacy of the cyclooxygenase-2 nonsteroidal antiinflammatory drugs, celecoxib and rofecoxib, have not been evaluated after major orthopedic surgery. This study was designed to determine whether the administration of a preoperative dose of celecoxib or rofecoxib to patients who have undergone spinal stabilization would decrease patient-controlled analgesia (PCA) morphine use and/or enhance analgesia. We evaluated 60 inpatients undergoing spine stabilization by one surgeon. All patients received PCA morphine. The patients were divided into three groups. Preoperatively, they were given oral celecoxib 200 mg, rofecoxib 50 mg, or placebo. The outcome measures included pain scores and 24-h morphine use at six times during the first 24 postoperative h. The total dose of morphine and the cumulative doses for each of the six time periods were significantly more in the placebo group than in the other two groups. The morphine dose was significantly less in five of the six time intervals in the rofecoxib group compared with the celecoxib group. The pain scores were significantly less in the rofecoxib group than in the other two groups at two of the six intervals, and less than the placebo group in an additional interval. Although both rofecoxib and celecoxib produce similar analgesic effects in the first 4 h after surgery, rofecoxib demonstrated an extended analgesic effect that lasted throughout the 24-h study. We thus recommend that rofecoxib be used as a preoperative component of pain management that includes PCA morphine in patients undergoing spine stabilization surgery.

IMPLICATIONS

The cyclooxygenase-2-specific nonsteroidal antiinflammatory drugs, celecoxib and rofecoxib, both demonstrate an opioid-sparing effect after spinal fusion surgery. Celecoxib resulted in decreased morphine use for the first 8 h after surgery, whereas rofecoxib demonstrated less morphine use throughout the 24-h study period.

Current trends in perioperative pain management

Wider use of optimized multimodal accelerated postoperative recovery programs require that anesthesiologists step out of traditional operating room anesthesia roles and even beyond current pain management consultant roles. Development of optimal postoperative recovery services requires close collaboration between anesthesiologists, surgeons, nurses, physical therapists, administrators, and others involved in the management of patients after surgery. Optimization of perioperative care is an ongoing process enhanced by clinical investigation; however, making significant improvements to clinical practice does not have to wait for additional research data, but should proceed now, with broader application of techniques known to enhance rehabilitation and recovery. Based on existing data, the challenges of developing perioperative recovery services seem likely to be rewarded with improved patient outcomes and reduced cost.

Local and regional anesthesia

Local anesthetics have the unique ability to produce complete blockade of sensory nerve fibers and prevent or pre-empt the development of secondary (central) sensitization to pain. For this reason, local and regional anesthetic techniques are often used with opioids, alpha 2-receptor agonists, dissociatives, and anti-inflammatory drugs as part of a multimodal strategy to manage pain. Lidocaine and bupivacaine are the local anesthetics used most commonly in dogs and cats. Lidocaine has a fast onset (10-15 min) and an intermediate duration of action (60-120 min), and is used for short diagnostic and surgical procedures. Bupivacaine has a slow onset (20-30 min) and a long duration of action (240-360 min), and is used to control pain both preoperatively and postoperatively. Local anesthetics are relatively safe if they are administered correctly. Administration of an excessive dose and accidental intravenous administration are probably the most common causes of systemic toxicity in small animals. Doses of local anesthetics, especially those for cats and small dogs, should always be calculated carefully. In many animals, the most simple and elegant way to control pain perioperatively is to perform a local or regional anesthetic block. Veterinarians should not hesitate to incorporate local and regional anesthetic techniques into their pain management strategies for dogs and cats.

Adjunctive analgesic therapy

Adjuvant analgesics are drugs that have weak or nonexistent analgesic action when administered alone but can enhance analgesic actions when coadministered with known analgesic agents. Such agents are often administered in cases of refractory pain. For some chronic pain syndromes, however, they may constitute a first-line approach. Because pain is such an individual experience, analgesic regimens may require several drugs at varying dosages to confer a comfortable state. Adjunctive therapies such as the tricyclic antidepressants, anticonvulsants, N-methyl-D-aspartic acid receptor antagonists and low-dose intravenous local anesthetics, to name a few, have proved to be efficacious in relieving certain types of pain, especially neuropathic and cancer pain. Their use in animals is increasing, with anecdotal reports of some success.

Physiology of pain

The substantial increase in our collective knowledge of pain physiology and pharmacology over the past decade has had a significant effect on the practice of clinical veterinary medicine. An overview of the basic anatomical and physiologic components of nociceptive processing is presented, as well as a discussion of the sensitizing events that occur within the nervous system in acute and chronic pathologic pain states. The unique features of visceral and neuropathic pain are also outlined. With the goal of improving the success of our therapeutic interventions, the final section is devoted to the various classes of analgesic drugs and techniques, and how they are best incorporated into pain management strategies.

The role of epidural anesthesia and analgesia in postoperative outcome

There is increasing evidence to support the hypothesis that epidural anesthesia and analgesia (EAA) can improve surgical outcome by reducing postoperative morbidity and hastening recovery. Likely benefits include decreased incidence of cardiac complications in high-risk patients; lower incidence of pulmonary complications, specifically pneumonia, atelectasis, and hypoxemia in patients at risk for pulmonary complications; lower incidence of vascular graft occlusion after lower extremity revascularization; lower incidence of DVT and pulmonary embolus; suppression of the neuroendocrine stress response; and earlier return of gastrointestinal function. Nonetheless, large multicenter prospective randomized studies are required to more definitively assess the impact of EAA on morbidity and mortality, ICU time, length of hospitalization, and cost of healthcare.

Anesthetics, sedatives, and paralytics. Understanding their use in the intensive care unit

This article reviews the use of inhalational, intravenous, and epidural agents used in the operating room and ICU. An emphasis is placed on the rationale for their selection. Additionally, the side effects and expected complications are discussed. By developing expertise with one's own repertoire of sedatives, narcotics, and neuromuscular blocking agents, one may decrease postoperative complications and lengths of stay.

The effect of diclofenac on the expression of spinal cord c-fos-like immunoreactivity after ischemia-reperfusion-induced acute hyperalgesia in the rat tail

Ischemia-reperfusion of the rat tail for 20 min induces local acute hyperalgesia of approximately 1-h duration. We studied how this stimulus affected the expression of c-fos-like immunoreactivity (c-fos-LI) labeling of neurons of the sacral spinal cord, and how diclofenac pretreatment influenced the outcome. After ischemia, the number of c-fos-LI-labeled neurons was significantly increased when assessed at 60, 90, and 120 min after reperfusion (to 183%, 283%, and 164% of control, respectively; all P < 0.01). At 90 min, the number of regional c-fos-LI-labeled neurons was increased to 585% in laminae I-II, 183% in laminae III-IV, 270% in laminae V-X, and 286% in total, compared with respective control values (all P < 0.01). After diclofenac pretreatment (subcutaneous 40 mg/Kg, 30 min before insult) the number of c-fos-LI-labeled neurons at 90 min was increased to 424% in laminae I-II, 150% in laminae III-IV, 142% in laminae V-X, and 183% in total (all P < 0.01). Thus diclofenac pretreatment partially prevented the insult-induced increase in total and regional neuronal c-fos-LI. This acute nociceptive model involves only natural algogens. However, the results were similar to acute chemically induced or chronic adjuvant induced arthritic inflammatory pain models in which increases in c-Fos were partially inhibited by nonsteroidal antiinflammatory drugs.

The efficacy of intravenous 0.15 versus 0.25 mg/kg intraoperative morphine for immediate postoperative analgesia after remifentanil-based anesthesia for major surgery

We evaluated the effect of perioperative administration of two doses of morphine for postoperative analgesia after remifentanil-based anesthesia. The prospective, randomized study included 245 patients from 33 centers. All patients were scheduled for abdominal or urological surgery lasting more than 1 h. General anesthesia used remifentanil as the perioperative opioid (1 microg/kg as a bolus then, 0.5 microg/kg as a continuous infusion). A morphine bolus of 0. 15 mg/kg (0.15-mg group) or 0.25 mg/kg (0.25-mg group) was administered 30 min before the end of surgery. In the postanesthesia care unit, pain scores for patients were evaluated by using behavioral pain scores of 1-3, verbal pain scores of 0-3, and visual analog scale scores of 0-10). Postoperative analgesia was obtained by a morphine titration (3 mg every 5 min). Demographic and surgery characteristics were similar in both groups. The delay for first demand of morphine was similar in the 0.15-mg and the 0.25-mg groups (26 [9-60] and 30 [10-60] min, respectively). The frequency of morphine titration was similar in both groups (75% and 66%, respectively). The amount of morphine used in the postanesthesia care unit was smaller in the 0.25-mg group (0.16 [0.0-1.25] vs 0.10 [0.0-0.56] mg/kg; P = 0.008). In the 0.25-mg group, the behavioral pain score was lower at 15 min, the verbal pain score was lower at 60 min (P < 0.001), and similar at 30 min. The visual analog scale pain score at 30 min and 60 min was similar in both groups. The incidence of minor side effects was similar in both groups. However, three cases of postoperative respiratory depression occurred in the 0.25-mg group compared with no cases in the 0.15-mg group. In conclusion, perioperative administration of morphine alone does not provide entirely adequate immediate postoperative pain control after remifentanil-based anesthesia in major surgery.

IMPLICATIONS

The administration of 0.15 or 0.25 mg/kg perioperative morphine during remifentanil-based anesthesia for major surgery does not preclude additional morphine administration in the postanesthesia care unit. The larger dose of 0.25 mg/kg slightly improves postoperative analgesia; however, it may be responsible for postoperative respiratory depression.

Diclofenac in the treatment of pain after caesarean delivery. An opioid-saving strategy

OBJECTIVE

Pain relief of good quality after caesarean section (CS) results in early mobilization and good early mother-child interaction. Patient-controlled analgesia (PCA), with systemic opioids, gives a very high level of patient satisfaction. However, opioids have well documented side-effects i.e. sedation, nausea and respiratory depression. To minimize the risk of such negative effects we studied how far the required dose of opioid could be decreased with a multimodal strategy adding diclofenac.

STUDY DESIGN

In a randomized double-blind study, 50 parturients scheduled for elective CS under spinal anaesthesia, received rectally either diclofenac (Suppositorium diclofenac) 50 mgx3 or placebo 1x3 during the first 24 h postoperatively. All patients had PCA with the possibility of self-administered doses of ketobemidone 1 mg/6 min.

RESULTS

In the group receiving diclofenac rectally the consumption of ketobemidone was reduced with 39% compared to the placebo group.

CONCLUSION

A multimodal analgetic strategy with the addition of 150 mg diclofenac during the first 24 h after CS reduces the need for opioids significantly with maintained or improved analgetic effect. This is expected to reduce the risk of negative side-effects of systemic opioids.

Patient supplemented epidural analgesia after major abdominal surgery with bupivacaine/fentanyl or ropivacaine/fentanyl

PURPOSE

To compare analgesic efficacy and occurrence of motor block and other side effects during patient supplemented epidural analgesia (PSEA) with either ropivacaine/fentanyl or bupivacaine/fentanyl mixtures.

METHODS

In a prospective, randomized, double-blind study, 32 ASAI-III patients undergoing major abdominal surgery received an epidural catheter at the T8- T10, followed by integrated general epidural anesthesia. Postoperative epidural analgesia was provided using a patient controlled pump with either ropivacaine 0.2%/2 microg x ml(-1) fentanyl (group Ropivacaine, n = 16) or bupivacaine 0.125%/2 microg x ml(-1) fentanyl (group Bupivacaine, n = 16) [background infusion 4-6 ml x hr(-1), 1.5 ml Incremental Doses and 20 min lock out]. Verbal pain rating score, number of incremental doses, consumption of epidural analgesic solution and rescue analgesics, sedation (four-point scale), and pulse oximetry were recorded by a blind observer for 48 hr after surgery.

RESULTS

No differences in pain relief, motor block, degree of sedation, pulse oximetry and other side effects were observed between the two groups. The number of incremental doses and the volume of analgesic solution infused epidurally were higher in patients receiving the bupivacaine/fentanyl mixture (10 [0-52] I.D. and 236 [204-340] ml) than in patients receiving the ropivacaine/fentanyl solution (5 [0-50] I.D. and 208 [148-260] ml) (P = 0.03 and P = 0.05, respectively).

CONCLUSION

Using a ropivacaine 0.2%/2 microg x ml(-1) fentanyl mixture for patient supplemented epidural analgesia after major abdominal surgery provided similar successful pain relief as bupivacaine 0.125%/2 microg x ml(-1) fentanyl, but patients receiving bupivacaine/fentanyl requested more supplemental.

Toward a canon of the pain and analgesia literature: a citation analysis

The purpose of this study was to use citation analysis to identify major themes and contributors to the pain and analgesia literature over the past two decades. A citation analysis was performed on a database of more than 110,000 articles in the biomedical literature from January 1981 through June 1997, and in the interval from January 1988 through June 1997. Articles and authors related to pain and analgesia research and practice were identified by searching approximately 7,700 journals. The 20 articles and 20 authors with the most citations were then checked by hand to ensure relevance to pain or analgesia. Most of the high-impact articles identified pertained to research on basic pain pathways. Nearly all the articles concerned opioids, nonsteroidal antiinflammatory drugs, and consequences of analgesic use. None of the highest-impact articles address assessment of clinical pain. Few women were first authors of any most frequently cited paper. Citation analysis is a useful tool in identifying important contributions to the biomedical literature. Recent and continuing research trends include the use of nonsteroidal antiinflammatory drugs, opioid mechanisms, and persistent pain disorders. Current trends expected to become stronger include description of pain from the patient's perspective and mechanisms of the transition from acute to chronic pain.

IMPLICATIONS

We performed a citation analysis to identify important contributions and contributors to the biomedical literature. Recent pain and analgesia research has been focused on mechanisms of pain, but evidence suggests the importance of understanding the pain experience from the patient's perspective and the transition from acute to chronic pain.

Postanaesthetic considerations and complications after ambulatory anaesthesia

Ambulatory or day-case surgery is being employed to an ever-increasing extent. Although it has many advantages, it is not suited to the needs of every patient. For example, patients who live alone, particularly the elderly, might well not be able to care for themselves adequately after such surgery and are probably at a higher risk of developing complications, including infections. Furthermore, pain treatment may be insufficient, as a consequence of which recovery can be prolonged and the resumption of normal daily activities might be delayed. Nausea, dizziness and vomiting can also prolong recovery and need to be adequately treated after ambulatory surgery. Therefore, the often cited cost effectiveness of ambulatory surgery is questionable if complications cannot be prevented or treated effectively.

Stability of buprenorphine, haloperidol and glycopyrrolate mixture in a 0.9% sodium chloride solution

Combinations of opioids and adjuvant drug solutions are often used in clinical practice while little information is available on their microbiological or chemical stability. Currently there are no commercially available, prepacked, ready-to-use epidural or subcutaneous mixtures. Thus, epidural and subcutaneous analgesic mixtures must be prepared in the pharmacy on an as-needed basis. Such mixtures are typically used for the treatment of severe pain in cancer patients. The aim of this study was to investigate the microbiological and chemical stability of a buprenorphine, haloperidol and glycopyrrolate mixture in a 0.9% sodium chloride solution. A high performance liquid chromatographic (HPLC) method and pH-meter were used to conduct the analyses. Antimicrobial activity of each component was studied by an agar dilution method. According to the results from the chemical and microbiological stability studies, this mixture can be stored in polypropylene (PP) syringes and polyvinyl chloride (PVC) medication cassettes for at least 30 days at either 21 degrees C or 4 degrees C, and for 16 days in PP syringes at 36 degrees C, and for 9 days in PVC medication cassettes at 36 degrees C.

Balanced analgesia: what is it and what are its advantages in postoperative pain?

The concept of balanced analgesia was introduced to improve analgesic efficacy and reduce adverse effects. A large amount of clinical data has documented improved analgesia by combining different analgesics, but data on reducing adverse effects are inconclusive. Balanced analgesia should be used whenever possible, and future studies should be directed to define optimal combination regimens in individual surgical procedures.

Femoral nerve block and ketorolac in patients undergoing anterior cruciate ligament reconstruction

PURPOSE

The primary objective was to evaluate the analgesic effectiveness of femoral nerve block and ketorolac following ACL reconstruction. The secondary objective was to examine their effects on recovery milestones.

METHODS

Prior to standard general anesthesia, 90 patients were randomized into three groups of preoperative treatment: 1) femoral nerve block (15 mL bupivacaine 0.5%) and 1 mL normal saline i.v. (FNB group); 2) placebo femoral nerve block (15 mL normal saline) and 30 mg (1 mL) ketorolac i.v. (KT group); 3) placebo femoral nerve block (15 mL normal saline) and 1 mL normal saline i.v. (PL group). Postoperatively, pain was assessed by visual analogue score, demand and consumption of morphine via patient-controlled analgesia pump. The times for patients to tolerate oral fluid, food, sit up, ambulate and void were also noted.

RESULTS

Morphine consumption within one hour, three hours and until POD 1 in the FNB group was lower than the PL group (7 +/- 6, 11 +/- 9, 27 +/- 23 mg vs 13 +/- 5, 20 +/- 9, 49 +/- 28 mg respectively), whereas only that within one hour in the KT group was lower than the PL group. Pain score was lower in FNB and KT groups in the first postoperative hour than in the PL group (P < 0.05). There were no differences among the three groups in the times to meet recovery milestone and discharge criteria.

CONCLUSION

Femoral nerve block provides superior analgesia than placebo for ACL reconstruction but was insufficient to facilitate early recovery.

A comparison of thoracic and lumbar epidural techniques for post-thoracoabdominal esophagectomy analgesia

PURPOSE

To compare thoracic epidural analgesia (TEA) using a bupivacaine/fentanyl mixture and lumbar epidural analgesia (LEA) with morphine, in respect to the time to extubation and the quality of post-operative analgesia, in patients having thoracoabdominal esophagectomy.

METHODS

Twenty two patients scheduled for elective thoracoabdominal esophagectomy were randomized to TEA or LEA. Postoperatively, the TEA group received Patient Controlled Epidural Analgesia (PCEA) with bupivacaine 0.125% and 5 microg x ml(BI) fentanyl, and the LEA group received PCEA with 0.2 microg x ml(BI) morphine. A blinded observer assessed criteria for tracheal extubation and the time of tracheal extubation was recorded. Early extubation was defined as tracheal extubation within four hours postoperatively. Visual analogue pain scores at rest (Static Visual Analogue Pain Scores, SVAPS) and with movement (Dynamic Visual Analogue Pain Scores, DVAPS) were recorded at 1, 6, 12, 18 and 24 hr post-extubation. Failure of the epidural protocol (FEP) was defined as a request for additional analgesia.

RESULTS

Tracheal extubation was achieved in 70% of the LEA and 100% of the TEA at four hours postoperatively (P=NS). However, the TEA group achieved earlier extubation times when assessed with log rank testing (P = 0.01). By six hours post-extubation FEP had occurred in 50% of the LEA group but in none of the TEA group (P = 0.01). Mean SVAPS and DVAPS were lower in the TEA than in the LEA group at all measured times (P < 0.01).

CONCLUSION

This study has demonstrated superior pain control in patients undergoing thoraco-abdominal esophagectomy treated with TEA than with LEA, particularly for pain with movement. Tracheal extubation occurred earlier in the TEA group, but this difference was not significant at four hours postoperatively.

Acute pain control and accelerated postoperative surgical recovery

Postoperative pain relief continues to demand our awareness, and surgeons should be fully aware of the potential physiologic benefits of effective dynamic pain relief regimens and the great potential to improve postoperative outcome if such analgesia is used for rehabilitation. To achieve advantageous effects, accelerated multimodal postoperative recovery programs should be developed as a multidisciplinary effort, with integration of postoperative pain management into a postoperative rehabilitation program. This requires revision of traditional care programs, which should be adjusted according to recent knowledge within surgical pathophysiology. Such efforts must be expected to lead to improved quality of care for patients, with less pain and reduced morbidity leading to cost efficiency.

Local and regional block in postoperative pain control

Local and regional block provides an effective means for the control of postoperative pain. In surgery involving the trunk, it serves as a useful alternative to epidural analgesia. With the increasing use of low molecular weight heparin, the use of peripheral nerve block is increasingly popular for patients undergoing lower limb surgery.

Analgesic agents for the postoperative period. Nonopioids

For many reasons, nonopioid analgesics have proven to be of immense benefit in postoperative pain relief. Consideration of the limitations and side effects of opioids confirms the need for alternative, complementary analgesics. The current understanding of pain pathophysiology recognizes that many tissue and neuronal factors and changes are invoked by tissue damage, producing peripheral and central sensitization, and some of these may be modulated by the use of NSAIDs, NMDA antagonists, and local anesthetic agents. If successful preemptive analgesic techniques are developed, they will likely include the use of NSAIDs and perhaps NMDA antagonists. Nonopioids are of benefit in multimodal analgesia and allow acute rehabilitation of surgical patients. Acetaminophen, NSAIDs, alpha 2-antagonists, and NMDA antagonists are in routine use as components of multimodal analgesia, in combination with opioids or local anesthetic techniques. Tramadol is interesting because it has nonopioid and opioid actions that can be attributed to the two isomers found in the racemic mixture. Spinal neostigmine and the use of adenosine represent completely different mechanisms of nonopioid analgesia being investigated. Nonopioids, including lidocaine, ketamine, the anticonvulsants, and the antidepressants, are necessary for the treatment of patients with the difficult clinical problem of neuropathic pain that can present in the postoperative period.

Postoperative pain control in ambulatory surgery

Optimizing postoperative pain control is the key to further advancement in the field of ambulatory anesthesia. The current situation in postoperative pain management indicates room for improvement, especially in the area of patient education and the development of individualized discharge analgesic packages. Multimodal analgesia provides superior analgesia with a lower side-effect profile. Preoperative administration of analgesia would decrease the intraoperative analgesic requirement, which may lead to a smooth and rapid recovery. Finally, new, portable analgesic delivery systems are under investigation and may prove to be the method of choice for future postoperative pain, management in ambulatory anesthesia.

A double-blinded evaluation of propacetamol versus ketorolac in combination with patient-controlled analgesia morphine: analgesic efficacy and tolerability after gynecologic surgery

We assessed the relative morphine consumption in a combined analgesic regimen (on-demand morphine plus the nonopioids propacetamol or ketorolac) after gynecologic surgery. Two hundred women randomly received two i.v. doses of propacetamol 2 g or ketorolac 30 mg in a double-blinded, double-dummy trial. Patients were monitored for 12 h, and the following efficacy variables were assessed: total dose of morphine, pain intensity, and global efficacy. Safety and tolerability were evaluated by the occurrence of adverse events, especially the presence and intensity of gastrointestinal symptoms. Hemostatic variables were measured 30 and 60 min after the first infusion; arterial blood pressure, heart and respiratory rates, sedation scores, and renal and hepatic function were also assessed. Total morphine requirements were not significantly different between the propacetamol (10.6 +/- 4.8 mg) and ketorolac (10.2 +/- 4.4 mg) groups. The evolution of pain intensity and the global efficacy also showed similar patterns in the two groups: 70.2% of patients in the propacetamol group rated the efficacy as "good/ excellent" compared with 68.2% in the ketorolac group. There were no clinically significant changes in vital signs or laboratory values and no observed differences between the two groups, although ketorolac slightly, but not significantly, prolonged the bleeding time. Epigastric pain was present in 9% and 15% of patients receiving propacetamol and ketorolac, respectively. There were two adverse events in the propacetamol group and four in the ketorolac group. Propacetamol demonstrates an efficacy similar to that of ketorolac and has an excellent tolerability after gynecologic surgery.

IMPLICATIONS

Propacetamol and ketorolac, combined with patient-controlled analgesia morphine, show similar analgesic efficacy after gynecologic surgery. Morphine consumption and pain scores were comparable in the two studied groups. Propacetamol is as effective as ketorolac and has an excellent tolerability after gynecologic surgery.

Diclofenac does not decrease renal blood flow or glomerular filtration in elderly patients undergoing orthopedic surgery

Nonsteroidal antiinflammatory drugs (NSAIDs) have become increasingly popular in the treatment of perioperative pain. Due to concerns that cyclooxygenase inhibition may adversely affect renal function, these drugs are often not used in geriatric surgical patients. However, the perioperative effect of NSAIDs on renal blood flow (RBF) and glomerular filtration rate (GFR) has not been assessed. Therefore, using a prospective, controlled, double-blinded study design, we evaluated the effect of diclofenac on RBF and GFR in 20 patients (>65 yr) undergoing open reduction and internal fixation of the femur. All patients were normovolemic before the study. A standardized general anesthetic was administered. On induction of anesthesia, patients in the diclofenac group received an IV bolus of diclofenac (0.7 mg/kg) followed by a constant infusion (0.15 mg x kg(-1) x h(-1)) until the end of surgery. In the saline group, an equal volume of saline was administered. During four time periods (equilibration, anesthesia, surgical, recovery), GFR and effective renal plasma flow (ERPF) were measured by inulin and paraaminohippurate clearance, respectively. After the induction of anesthesia and throughout the surgical period, ERPF and GFR were significantly decreased compared with preoperative baseline values. However, no difference was demonstrated between the groups. These results suggest that, in geriatric surgical patients, the adjuvant administration of NSAIDs does not adversely affect renal function.

IMPLICATIONS

As determined by inulin and paraaminohippurate clearance, the intraoperative administration of diclofenac does not decrease glomerular filtration rate or effective renal plasma flow in normovolemic geriatric patients. Therefore, diclofenac may be administered during the perioperative period.

What is new in monitored anesthesia care?

The use of monitored anesthesia care (MAC) techniques is increasing in popularity because recovery profiles seem to be improved compared with general and regional anesthesia. This article describes the conceptual basis for MAC and reviews the current MAC practices.