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May 1998
Patient-controlled epidural analgesia with bupivacaine and fentanyl on hospital wards.
Liu SS, Allen HW, Olsson GL; Anesthesiology 1998;88:688-95.
[ see abstract below ]
Widespread use of epidural analgesia with opioids and/or local
anesthetics and patient-controlled analgesia using intravenous opioids
have substantially improved postoperative analgesia in the last twenty
years. A technique which combines both of these, patient-controlled
epidural analgesia (PCEA), was first reported in obstetric patients in
1990 and has been further studied in relatively small numbers of
obstetric and postoperative patients.
A study from the Virginia Mason Medical Center in the current issue of
Anesthesiology investigates the efficacy and safety of PCEA in over one
thousand patients cared for on hospital wards. Spencer Liu and his
colleagues report on the one-year experience with the technique that has
become their most frequently used (82% of their post-operative pain
management practice) therapeutic modality. Catheters were placed
preoperatively at a vertebral level corresponding to the dermatomal
level of surgical incision. A standard solution of 0.05% bupivacaine
with 4 mcg/ml fentanyl at 4 ml/hr background infusion and 2 ml PCEA
bolus with a 10 min lockout was used. Of particular utility are the
appendices to the paper containing standardized PCEA medication orders
(including treatment of inadequate analgesia), treatment of side effects
and nursing observation.
Despite remarkably low drug usage (0.06 mg/kg/hr of bupivacaine and 0.5
mcg/kg/hr of fentanyl, assuming 70 kg), patients had low median pain
scores at rest and with activity on POD 1 (1 and 4, respectively). Pain
scores improved progressively on successive days. Incidences of side
effects overall were relatively low; the only serious side effects were
respiratory depression and sedation requiring naloxone in two patients.
| Potential Benefits of PCEA |
Demonstrated this Study |
Documented Elsewhere |
| Improved analgesia |
|
vs. continuous epidural |
| Improved satisfaction |
|
vs. epidural boluses, also for IV PCA |
| Lower incidence side effects |
|
No direct comparisons |
| Less nursing intervention vs. continuous infusion or boluses = reduced costs |
|
For IV PCA |
| Potential Risks of PCEA |
Demonstrated this Study
% Incidence (95% CI) |
Documented Elsewhere
% Maximal risk |
Respiratory depression
(<6 breaths/min) |
0.03 (0 - 0.6) |
0.2 - 1.9 |
| Hypoxemia (SpO2 < 85%) |
|
Lower incidence than with continuous epidurals |
| Sedation |
12 (10 - 14) mild
0.1 (0 - 0.2) difficult to rouse |
9 - 24 |
| Pruritus |
17 (15 - 19) |
12 - 28 |
| Nausea |
15 (13 - 17) |
6 - 32 |
Motor Block
(unable to walk) |
2 (1 - 3) |
4 - 12 |
Hypotension
(<90 mmHg systolic) |
7 (5 - 9) |
3 - 8 |
| High spinal block |
0 |
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| Systemic toxicity |
0 |
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I believe that the authors have supported their conclusions that PCEA
used with appropriate protocols and nursing observation can be used to
provide effective and safe post-operative analgesia on hospital wards.
Further work on the optimal drug combinations and concentrations will be
useful.
Return to the Current Literature Review Front Page, or read the abstract:
ABSTRACT
BACKGROUND: The efficacy and safety of patient-controlled epidural analgesia (PCEA) for postoperative analgesia on hospital wards was studied.
METHODS: Postoperative analgesia was provided for 1,030 patients with PCEA using 0.05% bupivacaine and fentanyl, 4 microg/ml, in a standardized manner. Patients were seen at least twice a day by the staff of the anesthesia pain management service. Prospectively gathered data included verbal pain scores at rest and activity (0-10); consumption of bupivacaine and fentanyl; and incidences of pruritus, nausea, sedation, hypotension, motor block, and respiratory depression. Descriptive statistics were used. Risk factors for side effects were determined using logistic regression.
RESULTS: The study included 552 women and 477 men who underwent a median (mode) of 3 (2) days of PCEA. Their mean age was 59 +/- 16 yr and their mean weight was 76 +/- 19 kg. There were 454 abdominal, 165 gynecologic, 126 urologic, 108 vascular, 90 thoracic, 83 orthopedic, and 4 plastic surgical procedures. Median (mode) pain scores were 1 (0) at rest and 4 (5) with activity on postoperative day 1. Incidences of side effects were 16.7% (pruritus), 14.8% (nausea), 13.2% (sedation), 6.8% (hypotension), 2% (motor block), and 0.3% (respiratory depression). Reasons for termination of PCEA were elective (82%), displaced epidural catheter (12%), anticoagulation (3%), infection (1%), side effects (1%), inadequate analgesia (1%), and other (<1%). Risk factors for side effects were female sex, patient weight <73 kg, patient age <58 yr, bupivacaine and fentanyl consumption >9 ml/h, use of analgesic adjuncts, and lumbar placement of epidural catheters.
CONCLUSION: Patient-controlled epidural analgesia provides effective and safe postoperative analgesia on hospital wards.
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