PCA Device Research Articles

Analgésie contrôlée par le patient : étude de la demande en fentanyl chez le brûlé à la phase aiguë

This study assessed over the first post-burn week the patients' demands for opiates delivered with a PCA device, changes in opioid delivery along the day, especially during painful events and the incidence of side effects. Twenty-two patients (8 women, 14 men), mean age 33 years (± 12 SD), mean BSA 21 % (± 13 SD), mean deep dermal burn 12 % (± 11 SD) were included. Fentanyl was delivered by i.v. route using a PCA device during the first 6 days post burn. Bolus dose was fixed at 1 μg · kg −1, lock-out time at 30 min and the 4 h limit dose at 7 μg · kg −1. The following data were collected every day : satisfied and non-satisfied demands, total daily dose, demands during and after dressing change period (4 h), during afternoon (10 h) and overnight periods (10 h). Heart rate (HR), respiratory rate (RR), blood pressure (BP), Pa co 2 and Sp o 2 were also monitored. The mean total daily demands were similar from D1 to D6 (28 ± 7). Around 7 demands/day were not satisfied. The mean total daily satisfied demands were also the same : 21 ± 5. Individual demands were over a wide range (minimum : 15, maximum : 41 demands/day for total demands and 13 and 34 respectively for the satisfied ones). Mean fentanyl delivery was 1,7 ± 0,1 μg · kg −1 · h −1 during dressing period, 0,9 ± 0,3 μg · kg −1 · h −1 during afternoon period (10 h) and 0,5 ± 0,2 during overnight period (10 h). No-satisfied demands were around 4 boluses during dressing change period, 2 boluses during afternoon period, and one bolus during overnight period. Neither HR nor BP were modified for more than 20 % of control values ; RR never decreased under 12 c · min −1 and Pa co 2 remained unchanged. This study showed that the provision of analgesia in burn injury requires large doses of opioids. Individual demands are scattered over a wide range. The need for analgesics remains unchanged for several days. A PCA device is an efficient and safe tool for administration of opioids. Analgesia is appropriate, except during the dressing period.

PCA devices

PCA devices

Intravenous or Epidural Clonidine for Intra- and Postoperative Analgesia

Intravenous and epidural clonidine both produce postoperative analgesia. Several experimental reports demonstrate a spinal site of action for the analgesic effects of this alpha 2-adrenoceptor agonist. Therefore, the authors evaluated the clinical analgesic benefits of using clonidine, both intra- and postoperatively, by the epidural or the intravenous route. Using a randomized prospective double-blind study design, 40 patients, between 18 and 50 yr of age, undergoing intestinal surgery under general propofol/nitrous oxide anesthesia, were enrolled. Before anesthesia, an epidural catheter was inserted at the L1-L2 interspace. At induction, a clonidine infusion was started at the doses of 4 micrograms/kg in 10 ml during 20 min, followed by 2 micrograms.kg-1 x h-1 (5 ml/h) during 12 h, either by the epidural (group 1) or by the intravenous (group 2) route. Intraoperatively, increased blood pressure and heart rate not responding to additional propofol bolus (0.5 mg/kg) was treated with a bolus of alfentanil (7 micrograms/kg). Postoperatively, morphine boluses (1.5 mg) were given through a PCA device according to the patient's need. Intraoperative analgesia was assessed by the alfentanil requirements. Postoperative analgesia was assessed by recording the morphine requirements, the visual analogue scale (VAS) at rest and after mobilization, and the patients' analgesia scale at 0, 3, 6, 12, 18, 24, and 36 postoperative hours. Sedation analogue scale and side effects were also recorded. Heart rate and blood pressure were particularly detailed during the first 2 h of the clonidine infusion. Plasma clonidine concentrations were measured after 20 min and 6, 12, and 24 h. Epidural clonidine significantly reduced the intraoperative alfentanil requirements (0.93 +/- 1.2 in group 1 vs. 2.4 +/- 1.8 mg in group 2). The postoperative morphine requirements were also reduced during the first 6 h (8.3 +/- 5.8 in group 1 vs. 17.8 +/- 13.4 mg in group 2). The VAS were comparable in both groups, despite the better patients' analgesia score reported in the epidural group during the first 12 h. There was no difference in sedation score at any time interval considered. Epidural and intravenous clonidine reduced heart rate and blood pressure to the same extent. The plasma clonidine concentrations were less in the epidural group only after the loading doses. Epidural clonidine reduces the intra- and early postoperative analgesic requirements when compared with the same dose given by the intravenous route. The side effects were similar with the two routes of administration.

Complications of Acute Pain Management

Summary Acute pain management is rapidly evolving to become a challenging and gratifying subspecialty of anesthesiology that allows the anesthesiologist to extend his or her skills beyond the confines of the operating room. But our enthusiasm must be tempered by caution. Do the benefits outweigh the costs? There is still only preliminary evidence that improved analgesia has a salutary effect on outcome. However, as pain management becomes more complex, so too does the management and prevention of side effects, errors, and accidents. Problems common to opioid use by all routes of administration include nausea and vomiting, pruritus, and urinary retention; they are rarely dangerous but often distressing to the patient. Much more serious is the potential problem of respiratory depression. The overall incidence of dangerous respiratory depression is approximately 1%, regardless of route of administration, although patients who receive thoracic epidural opioids may be at increased risk. Other important factors include the general health of the patient, the dose administered, and in the case of spinal opioids, the concomitant administration of parenteral opioids. Errors in drug administration still account for many of the serious problems encountered with PCA and spinal opioid administration. With PCA, common errors include improper set up of the syringe and tubing and errors in programming. Fortunately, serious technical problems with PCA devices are rare. With epidural opioids errors include administration of the wrong dose or the wrong drug. The first line of defense against serious complications is to provide the necessary education and to develop the necessary policies and procedures that will permit nurses and physicians to safely care for these patients. Strategies directed at reducing or eliminating opioid administration are of secondary importance but are potentially exciting developments. Over the last four decades anesthesiology has progressed and matured to the point where it is difficult for the careful and prudent anesthesiologist to further improve surgical outcome by changes in the intraoperative management of anesthesia. The acute pain management service takes us beyond the operating room and provides us with a new and exciting opportunity to further improve patient care. The challenge is to ensure that the good we do outweighs the harm.

Patient-controlled analgesia: can client education improve outcomes?

This literature review considers research which would answer the questions: would preoperative information, by the nurse to the patient, about the use and purpose of a patient-controlled analgesia device (PCA) (a) reduce the amount of analgesic that the patient demanded from the device in the postoperative period; and (b) reduce the patient's overall experience of pain? The studies demonstrate wide variations in analgesic demand by patients using PCA, with high demand rates immediately postoperatively. In comparative PCA vs. intermittent intramuscular analgesic regimes, PCA users demonstrate higher overall drug usage. The hypothesis is not supported that, given free access to analgesic via a PCA, patients will administer sufficient analgesic to maintain a minimum effective analgesic concentration. Understanding how to use the PCA devices and what is expected of the patient is crucial to obtaining the optimum benefit from PCA. There is little mention of preparatory information given to patients in any of the studies. No studies addressed the question posted. There is a growing demand by patients for PCA. The question invites urgent investigation. The consequences for improving patient outcomes are considerable.

Does the Anesthetic Technique Influence the Postoperative Analgesic Requirement?

In order to determine the effect of two standard general anesthetic techniques on the postoperative analgesic requirement, 53 adults undergoing elective intra-abdominal surgery were randomly assigned to one of two anesthetic treatment groups according to an open parallel protocol design. One of the groups received an opioid-based anesthetic; the other group was administered an inhaled anesthetic. The postoperative analgesic requirement was quantified using a Baxter PCA device. The group receiving the opioid-based anesthetic required significantly less morphine in the recovery room (5.7 +/- 5.5 mg; mean +/- SD) compared with those receiving the conventional inhaled anesthetic (16.6 +/- 7.1 mg). During the first 8 hours after discharge from the recovery room there was a trend toward higher PCA morphine usage in the inhaled anesthetic group (25.6 +/- 15 mg vs. 18.6 +/- 13 mg); however, this difference was not statistically significant (p = 0.08). From 8 to 40 hours after surgery, the morphine usage was nonsignificantly higher in the opioid group (64 +/- 30 mg vs. 56 +/- 38 mg, p = 0.43). In conclusion, the general anesthetic technique used during an elective operation appeared to have little if any effect on the postoperative analgesic requirement after discharge from the recovery room.

Does the Anesthetic Technique Influence the Postoperative Analgesic Requirement?

In order to determine the effect of two standard general anesthetic techniques on the postoperative analgesic requirement, 53 adults undergoing elective intra-abdominal surgery were randomly assigned to one of two anesthetic treatment groups according to an open parallel protocol design. One of the groups received an opioid-based anesthetic; the other group was administered an inhaled anesthetic. The postoperative analgesic requirement was quantified using a Baxter PCA device. The group receiving the opioid-based anesthetic required significantly less morphine in the recovery room (5.7 +/- 5.5 mg; mean +/- SD) compared with those receiving the conventional inhaled anesthetic (16.6 +/- 7.1 mg). During the first 8 hours after discharge from the recovery room there was a trend toward higher PCA morphine usage in the inhaled anesthetic group (25.6 +/- 15 mg vs. 18.6 +/- 13 mg); however, this difference was not statistically significant (p = 0.08). From 8 to 40 hours after surgery, the morphine usage was nonsignificantly higher in the opioid group (64 +/- 30 mg vs. 56 +/- 38 mg, p = 0.43). In conclusion, the general anesthetic technique used during an elective operation appeared to have little if any effect on the postoperative analgesic requirement after discharge from the recovery room.

The use of a PCA device by parents or nurses for postoperative pain in children with cerebral palsy

The use of a PCA device by parents or nurses for postoperative pain in children with cerebral palsy

Epidural patient-controlled analgesia (PCA): an alternative to continuous epidural infusions

In a clinical study involving 16 surgical patients receiving epidural hydromorphone for postoperative analgesia, we compared the use of a continuous infusion technique to an intermittent bolus technique (involving the use of a PCA device). Although comparable analgesia was achieved in the 2 treatment groups during the 48 h study period, the hydromorphone usage (mean value ± S.D.) was significantly higher in the continuous infusion group (10.2 ± 3.6 mg vs. 4.6 ± 2.2 mg in the intermittent bolus group). In spite of this difference in the analgesic dosage requirement, the side effect profile was similar for the 2 groups. Further studies are needed to confirm this observation and to determine the implications with respect to postoperative recovery.

Patient-Controlled Analgesia-Reply

In Reply. —The letter by Drs Grey and Sweeney describes the apparent accidental overdosing of postoperative patient using PCA device. Given the pump settings (meperidine bolus doses of 10 to 15 mg [1.0 to 1.5 mL] at minimum intervals of 15 minutes), it is difficult to understand how the patient could have received 495 mg of meperidine within 20 minutes of initiating PCA therapy. Since PCA devices administer fixed bolus doses, it is not possible to set a dose volume of 1.0 to 1.5 mL. Assuming the patient was not accidentally (or intentionally) overdosed at the time that the opiate-containing syringe was loaded into the PCA device, it would seem that either siphoning of the drug (eg, failure of the one-way valve at the Y-connector) or mechanical malfunction of the pump (eg, runaway) occurred. Unfortunately, the State of Utah Office of the Medical Examiner did not have