Safety and efficacy of patient-controlled analgesia

Perioperative management of chronic pain patients with opioid dependency

PURPOSE OF REVIEW

In this article, we discuss the perioperative anesthesia and pain management of patients with chronic pain receiving chronic opioid administration. In our practice we may expect to be confronted with opioid-dependent patients in routine anesthesia practice and should acquire specific knowledge and skills to effectively manage the perioperative and acute pain management issues that arise.

RECENT FINDINGS

The number of patients treated chronically with opioids has increased steadily over the past decade; currently about 10% of all chronic-pain patients are treated with opioids. As these patients are no longer confined to terminally ill cancer patients, growing numbers of these patients are facing surgical interventions.

SUMMARY

In our clinical practice, we should employ multimodal pain management therapy by using an around-the-clock regimen of nonsteroidal anti-inflammatory drugs, cyclooxygenase-2 inhibitors, acetaminophen, and regional blockade. Dosing regimens should be individualized to optimize efficacy while minimizing the risk of adverse events.

Perianesthesia respiratory care of the bariatric patient

Our nation's obesity problem has reached epidemic proportions and is only projected to worsen. The morbidly obese patient is at risk for experiencing a multitude of health-related conditions. Morbidly obese patients are presenting for surgery at an increasing rate, especially with the growing popularity of weight-loss surgery. Therefore the perianesthesia nurse has to remain informed of optimal care strategies for this sometimes challenging population. The obese patient presents with distinct respiratory care considerations of which the perianesthesia nurse must be knowledgeable. This review article will specifically focus on the respiratory care of the bariatric patient presenting for surgery.

Remifentanilversus propofol for radio frequency treatment of atrial flutter

PURPOSE

Radio frequency treatment in cardiology generates short acute pain during the heating process. The present study evaluates two techniques used for sedation/analgesia for this procedure.

METHODS

Two groups of 20 patients each were studied prospectively. Patients were randomized to receive sedation for the procedure using either a patient-controlled analgesia device with remifentanil (Group R), or a target controlled infusion of propofol (Group P). Patients in Group R had a basal infusion of remifentanil 0.02-0.04 microg x kg(-1) x min(-1) with self administered bolus doses of 0.3 microg x kg(-1) i.v. every minute as required, with a delivery time greater than 30 sec. Patients in Group P had an initial plasma target concentration set at 3-4 microg x mL(-1).

RESULTS

Sedation scores were significantly higher in Group P, and two patients required supplementation with remifentanil and insertion of an laryngeal mask airway. Pain scores were higher in Group R, and two patients experienced muscular rigidity, one with transient apnea. Systolic blood pressure decreased significantly in Group P, and at the end of the procedure, PaCO(2) values were higher in that group (P < 0.01). Recovery time was significantly longer in Group P. Patient and physician satisfaction scores were similar in the two groups.

CONCLUSIONS

A basal infusion of remifentanil plus remifentanil patient controlled analgesia and target controlled infusion of propofol were adequate but not optimal techniques for sedation/analgesia for radio frequency treatment of atrial flutter.

An Iontophoretic Fentanyl Patient-Activated Analgesic Delivery System for Postoperative Pain: A Double-Blind, Placebo-Controlled Trial

An iontophoretic fentanyl HCl patient-activated transdermal system (fentanyl HCl PATS) is under development for the treatment of acute postoperative pain. The fentanyl HCl PATS is a needle-free, credit card-sized, preprogrammed system that is applied to the patient's upper outer arm or chest. The fentanyl HCl PATS was demonstrated to be superior to placebo in a previous trial; however, the randomization scheme used and the lack of control of entry pain level may have contributed to the lack of robust findings. We compared the fentanyl HCl PATS with placebo for acute postoperative pain management in a larger trial that addressed the limitations of the previous study. Adult patients admitted to the postanesthesia care unit after major surgery were titrated to comfort with opioids and randomized 1:1 to receive the fentanyl HCl PATS 40 microg or placebo for 24 hours. Supplemental IV fentanyl was available to patients upon request in both treatment groups for the first 3 hours after enrollment. The primary efficacy end-point was the percentage of patients who discontinued participation in the study because of inadequate analgesia. Pain intensity scores, patient global assessments (PGA), and investigator global assessments (IGA) were collected. Four-hundred-eighty-four patients (PATS, n = 244; placebo, n = 240) were enrolled. Fewer patients receiving the fentanyl HCl PATS discontinued because of inadequate analgesia compared with placebo (28.7% versus 60.0%; P < 0.0001). Mean last pain intensity scores were 3.5 and 5.4 for the fentanyl HCl PATS and placebo groups, respectively. Patients (73.4%, PGA) and investigators (72.1%, IGA) considered the fentanyl HCl PATS a good or excellent method of pain control. Treatment-related adverse events were similar between groups. This study demonstrated the superiority of the iontophoretic fentanyl HCl PATS over placebo for acute postoperative pain management.

Patient-controlled modalities for acute postoperative pain management

Although numerous clinical practice guidelines for pain management have been published throughout the last 12 years, inadequate pain relief remains a significant health care issue. Several patient-controlled analgesia (PCA) modalities are currently available for the treatment of acute postoperative pain, including intravenous (IV) PCA, epidural (PCEA), and oral PCA. Although PCEA and IV PCA are both commonly used modalities, IV PCA is considered the standard of care for postoperative pain management. Limitations of this modality do exist, however. Consequently, noninvasive PCA systems are under development to circumvent many of these limitations, including the fentanyl hydrochloride patient-controlled transdermal system (PCTS); (IONSYS Ortho-McNeil Pharmaceutical, Raritan, NJ) and a number of patient-controlled intranasal analgesia (PCINA) delivery systems. The objective of this article is to review the PCA modalities currently in use and to discuss those in development for the treatment of acute postoperative pain.

Effects of music on target-controlled infusion of propofol requirements during combined spinal-epidural anaesthesia

The sedative effects of music were evaluated using the bispectral index (BIS) during target-controlled infusion (TCI) propofol. A total of 110 women undergoing hysterectomy were randomly allocated to receive either music or no music. Propofol was administered using target-controlled infusion and the concentration adjusted gradually to achieve an observer's assessment of alertness/sedation (OAA/S) score of 3 intra-operatively. The haemodynamic and bispectral index values during the sedation phase were recorded. Interleukin-6 was evaluated before, immediately after and 1 h following intervention. The music group had a significant reduction in mean (SD) induction time of sedation: 12 (12) min vs. 18 (12) min, p < 0.01; propofol target concentration: 1.6 (0.3) microg.ml(-1) vs. 2.4 (0.4) microg.ml(-1), p < 0.0001; intra-operative amount of propofol: 171 (98) mg vs. 251 (92) mg, p < 0.0001; and significantly higher levels of satisfaction with their peri-operative care: 9.6 (0.6) compared to the control group: 8.1 (1.0), p < 0.0001. No other differences were found. The results show the influence of music on the induction time of sedation, concentration and level of propofol during surgery, and suggest sedative benefits of music.

Analgesic efficacy of diclofenac in combination with morphine and paracetamol after mastectomy and immediate breast reconstruction

BACKGROUND

Breast cancer treatment with mastectomy and immediate breast reconstruction (IBR) is associated with intense pain in the primary post-operative period. The present prospective, placebo-controlled and double-blind study aimed to evaluate the analgesic efficacy of diclofenac, a non-steroid anti-inflammatory drug (NSAID), in combination with paracetamol and opioids. This was done by 64-h assessment of post-operative pain intensity, opioid consumption, blood loss, nausea and tiredness.

METHODS

Fifty women selected for mastectomy and IBR with submuscular implants with or without axillary lymph node dissection (ALND) were randomized to receive diclofenac 50 mg x 3 or placebo rectally in addition to oral paracetamol and intravenous opioids delivered using a patient-controlled analgesia (PCA) technique.

RESULTS

During the first 20 h post-surgery, patients who received diclofenac experienced significantly less pain when resting than those who received placebo. When moving, a non-significant estimated difference in pain in favour of diclofenac was also noted. Opioid consumption during the first 6 h post-operatively was 34% less with diclofenac than with placebo. Means (SD) were 16.9 (10.3) mg and 25.6 (10.2) mg, respectively (P = 0.007). After 64 h, the difference was no longer statistically significant. Post-operative bleeding was significantly higher with diclofenac than with placebo (P < 0.01). Nausea and tiredness did not differ between the groups.

CONCLUSIONS

The addition of NSAID to paracetamol and opioid-PCA reduced opioid consumption and improved pain relief during the first 20 h at rest but was not convincingly effective during mobilization. Post-operative blood loss was higher with diclofenac.

Pain Evaluation in Patients Receiving Intravenous Patient-Controlled Analgesia After Surgery

STUDY OBJECTIVE

To evaluate the effectiveness of intravenous patient-controlled analgesia (PCA) in patients after surgery.

DESIGN

Prospective, observational study.

SETTING

University teaching hospital.

PATIENTS

Sixty patients with American Society of Anesthesiologists physical status I-III receiving intravenous PCA for postoperative pain. The PCA was programmed to deliver morphine 1 mg or hydromorphone 0.1-0.2 mg, with a lockout interval of 10 and 6 minutes for 80% and 20% of the patients, respectively.

MEASUREMENTS AND MAIN RESULTS

Patients were asked, up to 4 times during PCA use and once within 4 hours after PCA use, to describe and rate their intensity of pain at rest and after activity. During the first 12 hours of intravenous PCA use, 75% of the patients reported moderate-to-severe pain > or = 5 on a verbal numeric rating scale) at rest, 80% after activity. Corresponding values, respectively, were 33% and 72% for the 12-24-hour period, 43% and 76% for the 24-36-hour period, and 36% and 64% for the 36-48-hour period of intravenous PCA use. Within 4 hours of stopping PCA, 30% and 58% of the patients had moderate-to-severe pain at rest and after activity, respectively. In approximately 50% of patients, presence of pain was described with words signifying sensory and affective dimensions of pain. Pain control was rated as good or very good by 54% of patients during the first 12 hours of intravenous PCA. Ratings of pain control tended to improve with time.

CONCLUSION

Successful postoperative pain management using PCA is difficult to achieve on a consistent basis unless treatment is individualized. Our data support the hypothesis that small fixed doses fail to achieve adequate relief in many patients.

Pain management after lumbar spinal fusion surgery using continuous subcutaneous infusion of buprenorphine

PURPOSE

The continuous subcutaneous infusion (CSI) technique is a simple, inexpensive method for managing postoperative pain. We examined the analgesic effects of CSI of buprenorphine in patients undergoing lumbar spinal fusion surgery.

METHODS

The patients were randomly assigned to one of three groups for postoperative pain management: control group (n = 17), high-dose buprenorphine group (BH group, n = 17), and low-dose buprenorphine group (BL group, n = 16). Infusion solutions containing buprenorphine at concentrations of 25.0 and 16.7 microg x ml(-1) combined with droperidol at a concentration of 52.0 microg x ml(-1) were used in the BH and BL groups, respectively; and an infusion solution containing droperidol at a concentration 52.0 microg x ml(-1) was used in the control group. CSI of each solution was started at a rate of 1 ml x h(-1) and was continued for 48 h.

RESULTS

The BH and BL groups showed significantly lower scores than the control group on the Visual Analogue Scale. There were significantly fewer administrations of flurbiprofen as a supplemental analgesic in the BL and BH groups than in the control group. The incidences of sedation and nausea were comparable in the three groups. The median number of administrations of flurbiprofen was significantly less in the BH group than in the control group on the day of the operation and on the first postoperative day, whereas the number in the BL group was less than that in the C group only on the day of the operation.

CONCLUSION

CSI of buprenorphine effectively reduces pain after lumbar spinal fusion surgery without apparent side effects. This technique is simple and useful for postoperative pain management.

Intravenous patient-controlled analgesia: one size does not fit all

Patient-controlled analgesia was introduced as a technique that would allow greater flexibility in opioid delivery for the management of acute pain. However, so far, any benefit compared with conventional methods of pain relief appears to be small. This article reviews some of the factors that could limit the usefulness of intravenous patient-controlled analgesia in the clinical setting and what strategies might allow patient-controlled analgesia to become more effective.

Recent developments in patient-controlled analgesia

Patient-controlled analgesia (PCA) has become the gold standard for acute pain management since it was first introduced 20 years ago, and its merits have been discussed in quite a large number of publications. This review summarizes the more recent developments, such as new application devices and strategies, including intranasal, spinal, and regional PCA; patient-controlled sedation; experience with children and elderly people; and some data from chronic pain situations. Analyzing PCA literature from 2001 onwards confirms the author's long belief that the PCA principle ("WYNIWYG": what you need is what you get) was the most important aspect of a patient-controlled strategy, more or less independent of the type of drug or machine. Discovering this principle has changed the understanding of pain and suffering.

Strategies for postoperative pain management

Despite advances in our understanding of the neurobiology of nociception, postoperative pain continues to be undertreated. There are many modalities that may provide effective postoperative analgesia, including systemic (e.g. opioids, non-steroidal anti-inflammatory agents) and regional analgesic options. The particular modality or modalities utilized for a particular patient will depend on the risk-benefit profile and patient preferences. Ideally, analgesic options should be incorporated into a multimodal approach to facilitate patient recovery after surgery.

Surdosage en morphine par cumul d’erreurs provoquant un dysfonctionnement d’une pompe d’analgésie

We report the case of a 67-year-female patient treated with a postoperative patient controlled analgesia using an Abbott Gemstar pump for after nephrectomy. In the postanaesthesia care unit, fifteen minutes after connecting with of the pump (which bag contained 100 mg of morphine) to the patient, respiratory arrest occurred. A morphine overdose was caused by uncontrolled delivery of the entire bag contents by free flowing due only to gravity. The patient was resuscitated immediately, and had uneventful recovery. This incident was the result of multiple misuse: one misconnection of the tubing between morphine bag and the patient thus shunting the antisiphon valve, and two an improper secured PCA cassette in an open position not detected by the pump. The tubing of these pumps and the software were subsequently modified by Abbott, which should reduce the risk of recurring incident. This accident points out that vigilance must remain rigorous in spite of widespread routine use of PCA.

Anaesthetics

Anaesthesia, like all other medical specialities continues to advance, with improvements in the agents used and techniques employed in order to minimise adverse effects to the patient. This review examines some of these advances and looks forward to what the future might hold in other areas. As well as purely technical advances, other facets of anaesthetic service provision are reviewed, paying particular attention to how to provide a high quality service within the constraints of current working time legislation and revalidation.

[Organization model for postoperative pain management in a basic-care hospital]

Small hospitals often lack the financial and personnel resources to realize innovative postoperative pain management concepts. This is not-as shown here-an absolute contradiction. The regular measurement of pain and its documentation by ward nurses as well as the appropriate prescription of analgesics play a key role in our concept. The joint establishment of guidelines, information sessions and the on-going dialog between the various professional groups guarantees the necessary consensus of all specialists involved in postoperative pain control. If an anesthetist is available 24 h a day, a nurse-based acute pain service (APS) becomes available for managing patients with patient-controlled analgesia (PCA) systems. The use of PCA and the performance of pain visits at regular intervals increase patient comfort and satisfaction. In addition, it can contribute to reduced hospitalization time in the context of fast-track rehabilitation programs. In our opinion, embedding the measures in a quality management program has a valuable catalytic effect, although implementation takes at least 1-2 years.

A background infusion of morphine enhances patient-controlled analgesia after cardiac surgery

PURPOSE

We compared the efficacy of patient-controlled analgesia (PCA), with or without a background infusion of morphine, on postoperative pain relief in patients extubated in the operating room after coronary artery bypass grafting (CABG) surgery.

METHODS

With Faculty Ethics approval, 60 consenting adults undergoing elective coronary artery surgery were randomly assigned to receive either morphine PCA alone (group PCA-A, n = 30) or morphine PCA plus a background infusion (group PCA-B, n = 30) for 24 hr postoperatively. Pain scores with verbal rating scale (VRS; from 0 to 10) at rest, sedation scores, morphine consumption and delivery/demand ratios were assessed at zero, one, two, four, six, 12 and 24 hr after surgery. Hemodynamic variables and arterial blood gases were also recorded in the same periods.

RESULTS

Sedation scores in the two groups were similar. At all study periods after the first postoperative hour, VRS remained below 5 in both groups. Pain scores were significantly lower in the background infusion group, which also had greater cumulative morphine consumption (61.7 +/- 10.9 mg vs 38.5 +/- 16.2 mg). There were no episodes of hypoxemia or hypertension.

CONCLUSION

Morphine PCA effectively controlled postoperative pain after cardiac surgery. The addition of a background infusion of morphine enhanced analgesia and increased morphine consumption.

Patient-controlled versus nurse-administered sedation with propofol during colonoscopy. A prospective randomized trial

OBJECTIVES

Patient-controlled sedation (PCS) with propofol, is well tolerated and reduces recovery time and staff required during endoscopic interventions. "Who" administers the drug proves economically crucial. With the aim of maintaining safety, medical quality, and patient satisfaction, this study investigates PCS versus nurse-administered propofol sedation (NAPS) in a cohort of consecutive patients.

METHODS

One hundred and fourteen patients, aged 22-90 yr, undergoing only colonoscopy participated in this prospective randomized trial. Patients were randomly assigned to either PCS or NAPS. If patients declined randomization for different reasons of reluctance to PCS they were assigned to a standard nurse-sedated control group. All patients received pethidine presedation for analgesia. Visual analogue scales followed patient anxiety level, tolerability, pain, and satisfaction, and endoscopist's assessment of the procedure.

RESULTS

Given the choice, 35% of the patients who were rather younger and more anxious declined randomization to PCS. The mean total dose of propofol needed in this group was higher, but the patients had a tendency to rate the global tolerance and the pain of the examination as less comfortable compared to the two randomized groups. Self-administration of propofol created a significantly different drug profile and higher medication costs. With regard to the safety parameters there was no difference between PCS and NAPS. In their global assessments, the patients and endoscopists tended to prefer NAPS.

CONCLUSIONS

Individual patient characteristics and attitudes toward self-control are crucial for PCS. While being a viable option for patients who are able and willing to handle, this technique is not applicable in a considerable portion of everyday patients.

Postoperative patient-controlled analgesia in the elderly: risks and benefits of epidural versus intravenous administration

Postoperative patient-controlled analgesia provided by the intravenous route using morphine (PCA) or by the epidural route using an opioid in combination with a local anaesthetic (patient-controlled epidural analgesia; PCEA) is not yet routinely used in the elderly. However, this modality theoretically provides adequate control of postoperative pain in such patients. Firstly, an assessment of the level of pain is particularly difficult in the elderly, and patient-controlled techniques that enable the self-administration of analgesic could resolve this problem. Secondly, these techniques provide a fine and controlled titration of analgesic doses. Since analgesic-induced adverse effects increase with age, the risk of overdose is therefore reduced. Thirdly, effective postoperative patient-controlled analgesia may attenuate detrimental physiologic responses, and contribute to improvement in patient outcomes. In the elderly, PCEA provides better pain relief, particularly for dynamic pain, and improves postoperative recovery with a low incidence of adverse effects compared with PCA. PCA and PCEA techniques have a good safety profile in the elderly only when there is careful preoperative patient selection and strict postoperative monitoring. Standard observation of vital signs, sedation and pain scores and assessment of mental status are required. Patient selection is necessary to identify those patients who may be incapable of using the device (e.g. patients with evidence of cognitive dysfunction or physical disabilities). In addition, caution is required among patients with respiratory, renal or hepatic insufficiency. PCA and PCEA are particularly useful for elderly patients undergoing major thoraco-abdominal surgery. However, there is a need for further research in elderly patients. In the future, improvements in the management of postoperative pain in the elderly will lead to a greater expansion of self-controlled techniques.

Respiratory Depression in Adult Patients With Intravenous Patient-Controlled Analgesia

Patient-controlled analgesia (PCA) has been widely implemented to provide better pain relief and increased patient satisfaction with relatively few side effects. However, patients using intravenous (i.v.) PCA are at increased risk for specific adverse effects, especially respiratory depression. A review of the literature from 1990 to present was done to identify the incidence and risk factors for respiratory depression and recommendations for care. Several studies have documented the incidence of respiratory depression with i.v. PCA; rates ranged from 0.19% to 5.2%. Variation in incidence existed because authors defined respiratory depression differently. Methods for monitoring oxygenation include sedation; respiratory rate, depth, and rhythm, and oxygen saturation using pulse oximetry. No single parameter is the single indicator for respiratory depression. Risk factors for respiratory depression with i.v. PCA include age greater than 70 years; basal infusion with i.v. PCA; renal, hepatic, pulmonary, or cardiac impairment; sleep apnea (suspected or history); concurrent central nervous system depressants; obesity; upper abdominal or thoracic surgery; and i.v. PCA bolus > 1 mg. Structures and processes should be in place to guide appropriate dosing, identify risk factors, and activate pertinent monitoring and frequency. Finally, respiratory depression occurs infrequently in comparison to the 10% of patients who are undertreated for pain.

An audit of post-operative nausea and vomiting, following cardiac surgery: scope of the problem

Post-operative nausea and vomiting is a major problem for patients following cardiac surgery. The literature in this area identifies that there are a number of individual patient and post-operative factors which increase the risk of post-operative nausea and vomiting, including female gender, non-smoker, age, use of opioids, pain and anxiety. An audit involving 200 patients, who had undergone cardiac surgery was implemented to assess/evaluate the incidence of nausea and vomiting for this patient group. Data collected included information relating to nausea and vomiting, pain, consumption of morphine and other individual patient variables. The results suggest that nausea and vomiting, is experienced by a large number of patients after cardiac surgery (67%), with the majority suffering on the first day after surgery. The duration of nausea and vomiting for most is short, but for a significant number (7%) it can last up to one-quarter of their initial post-operative course. The paper discusses key implications for practice arising from this project.

Intrathecal + PCA morphine improves analgesia during the first 24 hr after major abdominal surgery compared to PCA alone

PURPOSE

To compare, over a 48-hr follow-up period, the analgesia and side-effects of patient controlled iv analgesia (PCA) with morphine alone vs combined intrathecal and PCA morphine (IT+PCA) in patients undergoing major abdominal surgery.

METHODS

Sixty adult patients undergoing abdominal surgery for cancer were randomly allocated to receive preoperative IT (0.3 or 0.4 mg) plus postoperative PCA morphine or postoperative PCA morphine alone. Postoperative analgesia was tested at rest and while coughing on a visual analogue pain scale and morphine consumption was recorded. Patients' satisfaction, arterial oxygen saturation, respiratory rate, episodes of nausea, vomiting and pruritus were also noted.

RESULTS

Analgesia at rest and while coughing was significantly better in the IT+PCA morphine group (rest: P = 0.01; coughing: P = 0.005) on the first postoperative day only. IT+PCA morphine constantly provided adequate analgesia during this period. Morphine consumption was lower in the IT+PCA morphine group during this period also (IT+PCA: 9 (17) vs PCA: 40 (26); mg of morphine, mean (SD), P = 0.0001). No difference was found in pain relief and morphine consumption between the groups on the second postoperative day. Nausea and vomiting were more frequent with IT+PCA morphine on the first postoperative day. No respiratory depression occurred in either group. Satisfaction was high in both groups.

CONCLUSIONS

IT+PCA morphine improves patient comfort constantly during the first postoperative day after major abdominal surgery. However, after the first postoperative day, IT+PCA morphine provides no additional benefit.

Comparison between patient-controlled analgesia and subcutaneous morphine in elderly patients after total hip replacement

BACKGROUND

The goal of this study was to evaluate the effectiveness on postoperative pain, and cognitive impact, of patient-controlled analgesia (PCA) compared with subcutaneous (s.c.) injections of morphine in elderly patients undergoing total hip replacement (THR).

METHODS

Forty patients older than 70 yr were randomly assigned to two different postoperative analgesic techniques for 48 h: i.v. PCA morphine (dose, 1 mg; lockout interval, 8 min; PCA group) or regular s.c. morphine injections (SC group). Postoperative pain was assessed at rest and when moving, using a visual analogue scale (VAS) every 4 h. A Mini Mental Status (MMS) examination was used to assess cognitive functions before surgery, at 2 h, 24 h and 48 h after surgery, and at hospital discharge. Side-effects were also recorded systematically during the first 48 h after surgery.

RESULTS

The PCA group showed significantly lower pain scores than the SC group both at rest and during mobilization. However, the clinical significance of pain scores was weak. There was no intergroup difference in postoperative MMS scores. The incidence of side-effects was similar in both groups.

CONCLUSIONS

We conclude that in healthy elderly subjects undergoing THR, the flexibility of the analgesic regimen is more important than the route of administration with regard to efficacy, adverse effects and recovery of cognitive function.

The addition of a tramadol infusion to morphine patient-controlled analgesia after abdominal surgery: a double-blinded, placebo-controlled randomized trial

In this double-blinded, randomized controlled trial, we tested whether the addition of tramadol to morphine for patient-controlled analgesia (PCA) resulted in improved analgesia efficacy and smaller morphine requirements compared with morphine PCA alone after abdominal surgery in adults. Sixty-nine patients were randomly allocated into two groups, each receiving morphine 1 mg/mL via PCA after surgery. The tramadol group received an intraoperative initial loading dose of tramadol (1 mg/kg) and a postoperative infusion of tramadol at 0.2 mg. kg(-1). h(-1). The control group received an intraoperative equivalent volume of normal saline and a postoperative saline infusion. Postoperatively, tramadol was associated with improved subjective analgesic efficacy (P = 0.031) and there was significantly less PCA morphine use in the tramadol group (P = 0.023). No differences between the groups were found with regard to nausea, antiemetic use, sedation, or quality of recovery (all P > 0.05). We conclude that a tramadol infusion combined with PCA morphine improves analgesia and reduces morphine requirements after abdominal surgery compared with morphine PCA alone.

IMPLICATIONS

In this study, we determined whether adding a second pain-killing drug, tramadol, could improve pain relief after major surgery in patients receiving morphine patient-controlled analgesia. We found that patients receiving tramadol had significantly better opinions of their pain relief and used significantly less morphine with no increase in side effects.

How to implement an acute pain service

To implement a successful acute pain service the following factors are the most important for success: anaesthesiologist-supervised pain nurses and an ongoing educational programme for patients and all health personnel involved in the care of surgical patients. The benefits in increased patient satisfaction and improved outcome after surgery will far outweigh the costs of running an acute pain service that raises standards of pain management throughout the hospital. Optimal use of basic pharmacological analgesia will improve relief of post-operative pain for most surgical patients. More advanced approaches, such as well-tailored epidural analgesia, are needed to relieve severe dynamic pain (e.g. when coughing). This may reduce markedly risks of complications in patients at high risk of developing post-operative respiratory infections and cardiac ischaemic events. More aggressive methods for post-operative pain management need robust routines that will discover the early symptoms and signs of potentially serious complications. High preparedness must be present for swift and correct handling of the rare but potentially catastrophic complications of bleeding and infection in the spinal canal. Chronic pain is common after surgery. Better acute pain relief may reduce this distressing long-term complication of surgery. Research into the long-term effects of optimal neuraxial analgesia and drugs that dampen glutamatergic hyperphenomena (hyperalgesia/allodynia) are urgently needed to verify whether these approaches can reduce the problem of intractable chronic post-operative pain.

The rise and withdrawal of droperidol

Predicting which patients will experience postoperative nausea and vomiting is difficult. Prophylactic antiemetic administration has been shown to reduce unplanned admission after day case surgery. In published comparative studies of antiemetic efficacy, droperidol has been considered to be the 'gold standard' against which other agents are measured. The recent withdrawal of droperidol due to reports of cardiac arrhythmias and the potential for sudden death has left a vacancy for a safe and effective antiemetic. This article explores the published literature for alternatives to droperidol as a single dose or prophylaxis in patient controlled analgesia devices.