Chapter 37. Pain Management (continued)
Subchapter 37.3. Prophylactic Antiemetics During
Patient-controlled Analgesia Therapy
Background
Nausea and vomiting are common side effects of
patient-controlled analgesia (PCA) with opioids. When severe, nausea and
vomiting may limit a patient's tolerance of PCA. Giving antiemetics
prophylactically has been suggested as a way to prevent PCA-associated nausea
and vomiting.
Practice Description
No study has definitively determined the best prophylactic
antiemetic in patient-controlled analgesia. Prophylactic treatments that have
been used include droperidol, 5-HT3 receptor antagonists
(ondansetron, tropisetron), clonidine, promethazine, hyoscine, propofol and
metoclopramide. Prophylactic antiemetics have been given both at the induction
of anesthesia and at the end of surgery. A relatively new approach to minimizing
nausea and vomiting associated with PCA involves the addition of an antiemetic
to PCA, so that the patient receives both analgesic and antiemetic with each PCA
demand dose.
Prevalence and Severity of the Target Safety Problem
The incidence of postoperative nausea and vomiting has varied
widely (from 8 to 92%) among studies.1 There is no evidence that the
incidence of nausea and vomiting with PCA is any different than that with
intramuscular opioids. In patients receiving PCA, 57-90% report nausea and
27-40% report vomiting. There appears to be no clear advantage to using one
opioid over any others in PCA in terms of postoperative emesis.
Opportunities for Impact
The degree to which prophylactic antiemetics are used in
routine practice with PCA is unknown.
Study Designs
Tramer and Walder2 conducted a systematic search for
randomized trials (MEDLINE, Embase, Cochrane library, reference lists,
hand-searching, no language restriction) that compared prophylactic antiemetics
with placebo or no treatment in patients receiving postoperative PCA with
opioids. Their review identified 14 placebo-controlled trials with different
regimens of droperidol, ondansetron, hyoscine transdermal therapeutic system,
tropisetron, metoclopramide, propofol and promethazine. One PCA delivered
tramadol; all others delivered morphine.
Both relative risk and number needed to treat were calculated.
To estimate the frequency of drug-related adverse effects, the relative risk and
the number needed to harm were calculated.
Study Outcomes
The main end point for efficacy was prevention of emetic events
(Level 1). The incidence of emetic events with active treatments (experimental
event rate) and with placebo or no treatment (control event rate) was extracted.
Nausea, vomiting, and "any emetic event" (nausea, vomiting, or nausea and
vomiting) were extracted from each trial. Data on drug-related adverse effects
(Level 2) were extracted as well.
Evidence for Effectiveness of the Practice
Without antiemetic drugs, the incidence of nausea averaged 43%
(range 22-80%), vomiting 55% (45-71%), and any emetic event 67% (54-87%). At 24
hours postoperatively, the cumulative incidence of nausea and vomiting in
patients not receiving any antiemetic treatment added to their PCA-morphine was
approximately 50%.
The best-studied antiemetic was droperidol. It was added to
morphine-PCA in 6 placebo-controlled trials involving 642 patients. Droperidol
0.017-0.17 mg/mg of morphine (0.5-11 mg/d droperidol) was significantly more
effective (p=0.04) in preventing nausea than placebo, without evidence of
dose-responsiveness. Compared with placebo, the number needed to treat with
droperidol to prevent nausea was 2.7 (95% CI: 1.8-5.2) and to prevent vomiting
was 3.2 (95% CI: 2.3-4.8).
The second most frequently reported drugs were 5-HT3
receptor antagonists (ondansetron, tropisetron). Their effect on vomiting was
satisfactory, with numbers needed to treat of approximately 5 compared with
placebo. There was no evidence of any antinausea effect.
Promising results were shown with some of the other
interventions (clonidine, promethazine). However, the limited numbers of
patients studied did not generate sufficient evidence to make a
recommendation.
Potential for Harm
With placebo, the absolute risk of minor adverse events
(sedation, drowsiness and dizziness or anxiety, restlessness and agitation) was
0-20%. In those trials that reported adverse events with droperidol, doses of
the antiemetic ranged from 1.2 mg to cumulative doses of 7.4 mg. There were no
obvious differences in the incidence of minor adverse effects compared with
placebo with droperidol doses <4 mg. In all droperidol trials, 2
adverse effect-related study withdrawals were documented. No extrapyramidal
symptoms were documented in any trial.
Costs and Implementation
Costs of prophylactic antiemetics during patient-controlled
analgesia have not been evaluated. However, 1-4 doses of droperidol per day
(0.25-0.5 mL q 4 h) costs $2.83-$11.32 while 1-3 doses of ondansetron per day
costs $22.50-$67.50. Implementing prophylactic antiemetics during PCA seems
neither difficult nor time-consuming.
Comment
Postoperative nausea and vomiting is a common event and
patients may refuse to continue PCA because of these side effects. Prophylactic
droperidol appears to decrease such side effects. Of 100 patients who have
droperidol added to their PCA pump with morphine, 30 who would have vomited or
been nauseated had they not received droperidol will not suffer these
effects.
The results of this systematic review should be confirmed, as a
pooled effect size estimated by meta-analysis must be considered provisional.
Additional randomized, placebo-controlled trials assessing droperidol's
prophylactic efficacy in the morphine-PCA setting can establish its optimal use
in this clinical setting.
References
1. Woodhouse A, Mather LE. Nausea and vomiting in the postoperative
patient-controlled analgesia environment. Anaesth 1997;52:770-775.
2. Tramer MR, Walder B. Efficacy and adverse effects of prophylactic
antiemetics during patient-controlled analgesia therapy: a quantitative
systematic review. Anesth Analg 1999;88:1354-1361.
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Subchapter 37.4. Non-pharmacologic Interventions for
Postoperative Plan
Background
Over the past decade, increased attention has been paid to
non-pharmacologic interventions in conjunction with pharmacologic interventions
to treat postoperative pain. The Agency for Health Care Policy and Research's
(AHCPR) 1992 Clinical Practice Guideline on Acute Pain Management recommends
that preoperative preparation includes educating patients concerning pain
control. The Guidelines specifically state that management of postoperative pain
may include cognitive-behavioral interventions, such as relaxation, distraction,
and imagery.1 Nonetheless, non-pharmacologic interventions can only
be considered beneficial if postoperative pain is effectively decreased.
Practice Description
Non-pharmacologic interventions typically fall into 3
categories: healthcare information, skills teaching and psychosocial
support.2 Healthcare information includes information on preparation
for surgery, timing of procedures, functions and roles of healthcare providers,
self-care responsibilities, and pain/discomfort information. Skills teaching
includes coughing, breathing and bed exercises, hypnosis, cognitive reappraisal
and relaxation exercises. Relaxation strategies include such techniques as the
modified Jacobson method, Flaherty and Fitzpatrick jaw relaxation, relaxation
tapes, tapes with structured breathing, muscle relaxation and pleasant imagery,
and cognitive relaxation. Psychosocial support includes identifying and
alleviating concerns, providing reassurance, problem solving with the patient,
encouraging questions and increasing frequency of support.
Prevalence and Severity of the Target Safety Problem
The safety problem targeted by the practice of
non-pharmacologic interventions is postoperative pain. At least 40-50% of
postoperative patients report inadequate pain relief, despite pharmacologic
interventions.3 Postoperative pain can have deleterious psychological
and physiologic consequences that contribute to patient discomfort and longer
recovery periods, and may compromise outcomes.1 It also consumes
greater healthcare resources.
Opportunities for Impact
Non-pharmacologic interventions are increasingly used in
management of postoperative pain, although the exact proportion of patients
receiving such interventions is unknown.
Study Designs
We identified 7 meta-analyses of studies evaluating the
effectiveness of non-pharmacologic interventions on postoperative pain. Two of
these meta-analyses evaluated various non-pharmacologic interventions for the
management of acute pain. Devine2 conducted a meta-analysis of 191
studies looking at psychoeducational care (including all 3 intervention
categories above) for adult surgical patients. Sindhu3 conducted a
meta-analysis including 49 randomized controlled trials looking at
non-pharmacologic nursing interventions (preoperative education/information,
relaxation, music, imagery, biofeedback, multidisciplinary approaches and
others) for the management of acute pain. AHCPR1 conducted a
systematic search of non-drug intervention studies on postoperative pain
management. One hundred forty studies were included and formal meta-analysis of
3 was performed. The American Society of Anesthesiologists Task Force on Pain
Management, Acute Pain Section4 performed a systematic search for
acute pain management in the perioperative setting. Two hundred thirty-three
articles were used in the formal meta-analysis; the number of articles regarding
education of patients was not reported. Good5 performed a systematic
search of trials evaluating the effects of relaxation and music on postoperative
pain. Suls and Wan6 performed a systematic search of trials
evaluating the effects of sensory and procedural information on coping with
stressful medical procedures and pain. Seers and Carroll7 performed a
systematic review of various relaxation techniques for postoperative pain
relief. Table 37.4.1 lists the 7 articles and briefly describes their salient
features.
Study Outcomes
All studies reported postoperative pain (Level 1) as a primary
outcome measure. Other outcomes, such as recovery time, psychological distress,
and opioid intake were reported in some cases (Level 1).
Evidence for Effectiveness of the Practice
The extensive literature covered by the meta-analyses suggested
beneficial effects of psychoeducational care, education and instruction of
patients, music and relaxation techniques (Table 39.5.1). The 2 meta-analyses
that examined opioid intake failed to show an effect of non-pharmacologic
interventions in reducing postoperative opioid consumption.
Potential for Harm
One study7 reported no adverse events in any of the
trials for any of the treatment or control groups. Otherwise, adverse
consequences of non-pharmacologic interventions on postoperative pain management
were not addressed.
Costs and Implementation
Direct information on costs of non-pharmacologic interventions
was not reported in these 7 studies. Devine and Cook8 found that the
beneficial impact on length of stay and medical complications rendered
non-pharmacologic interventions cost-beneficial. Another review2
hypothesized that costs could potentially be decreased by non-pharmacologic
interventions, since the length of hospital stay was shortened by an average of
1.5 days (11.5%).
The most obvious direct cost of psychoeducational care is the
increased staff time to provide these services. Based on average treatment
duration of 42 minutes, a comprehensive version of the intervention would
probably not take more than 1 hour per patient.8 Less obvious direct
costs might result from staff time to plan the protocol for psychoeducational
care and/or to develop patient education materials, in-service programs or staff
meetings to teach or review the protocol, printing or purchasing patient
education materials, transporting patients to group teaching sessions, and staff
time to document the level of care provided.
Comment
Effective treatment of postoperative pain continues to be a
challenge. In addition to analgesia, non-pharmacologic interventions may provide
some benefit in reducing postoperative pain. Clinicians have a wide range of
options to consider when developing a comprehensive version of non-pharmacologic
care appropriate for their patients. As such interventions are low risk and
appeal to many patients, they should be explored in practice and further
research.
Table 37.4.1. Studies of non-pharmacologic interventions for postoperative
pain
| Study setting; Practice Examined |
Study Design, Outcomes |
Results* |
| Adult surgical patients (# not stated), 92% in American hospitals (45%
teaching, 43% general hospitals); healthcare information, skills teaching,
psychosocial support2 |
Level 1-3 A, Level 1 |
79-84% of studies found beneficial effects;
Average effect size values were 0.43 for recovery, 0.38 for pain, 0.36
for psychological distress;
Length of stay decreased 11.5% |
| Not reported; transcutaneous nerve stimulation, education/instruction,
relaxation1 |
Level 1-3 A, Level 1 |
Simple/complex relaxation techniques, education/ instruction effective
in reducing mild-moderate pain |
| Not reported; education and participation of patients and families in
pain control4 |
Level 1-3 A, Level 1 |
Education improves pain control, reduces adverse
outcomes |
| Adult pts who have undergone torso surgery (# not stated); relaxation
techniques, music5 |
Level 1-3 A, Level 1 |
Total pain decreased in 10 of 13 studies;
Sensory paina reduction was reported in 6 of 12 studies;
Affective painb decreased in 10 of 13 studies;
Unidimensional pain decreased in 4 of 7 studies;
Observed pain decreased in 4 of 4 studies |
| Not reported; sensory and procedural information (explanations of what
will be happening and how patients can expect to feel)6 |
Level 1-3 A, Level 1 |
Combination of procedural and sensory preparation significantly better
than control on all measures; effect sizes with combination larger than
with either type of information alone |
| 362 patients undergoing fractured hip repair, removal of malignant skin
lesions, major elective abdominal surgery, elective cholecystectomy,
abdominal hysterectomy, femoral angiography; jaw relaxation, imagery,
music, breathing, relaxation tapes7 |
Level 1-3 A, Level 1 |
3 of 7 studies showed significant decrease in pain sensation/pain
distress in those who had relaxation; 1 out of 5 trials showed significant
improvement in psychological outcomes; less anxiety in relaxation
group |
| 3387 adult patients; education, relaxation, music, imagery,
biofeedback, multidisciplinary approach3 |
Level 1-3 A, Level 1 |
Effect sizes ranged from 2.25 to 1.78; strong
heterogeneity |
* Effect size is the standardized difference between the control and
experimental groups regarding the measure of interest in each study. Positive
values indicate benefit with the intervention.
a Sensory pain refers to ability to discriminate where pain is occurring and
respond appropriately.
b Affective pain is the sensation of pain as something unpleasant and to be
avoided.
References
1. AHCPR Pain Management Guideline Panel. Clinicians' quick reference guide
to postoperative pain management in adults. J Pain Symptom Manage
1992;7:214-228.
2. Devine EC. Effects of psychoeducational care for adult surgical patients:
a meta-analysis of 191 studies. Patient Educ Couns 1992;19:129-142.
3. Sindhu F. Are non-pharmacological nursing interventions for the management
of pain effective?—a meta-analysis. J Adv Nurs 1996;24:1152-1159.
4. A Report by the American Society of Anesthesiologists Task Force on Pain
Management, Acute Pain Section. Practice guidelines for acute pain management
in the perioperative setting. Anesth 1995;82:1071-1081.
5. Good M. Effects of relaxation and music on postoperative pain: a review.
J Adv Nurs 1996;24:905-914.
6. Suls J, Wan CK. Effects of sensory and procedural information on coping
with stressful medical procedures and pain: a meta-analysis. J Consult Clin
Psychol 1989;57:372-379.
7. Seers K, Carroll D. Relaxation techniques for acute pain management: a
systematic review. J Adv Nurs 1998;27:466-475.
8. Devine EC, Cook TD. Clinical and cost-saving effects of psychoeducational
interventions.
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