Patient-Controlled Analgesia

Abstract

This report concerns evaluation of patient-controlled analgesia (PCA) in the form of two preliminary investigations. In the first study, the patient-controlled analgesia device, which consists of a pump linked to a timer so that patients can activate intravenous administration of morphine sulfate to themselves during the postoperative period, was used in seven morbidly obese patients. The amount of morphine used during the first 36 hours was found to vary between 32 and 185 mg, with a significant difference in drug usage when related to weight as well as to body surface area. In the second study, morbidly obese patients undergoing gastric bypass operations were prospectively randomized into 12 patients who used the PCA device in the postoperative period and 12 patients who were given standard intramuscular dosages of morphine sulfate. An analgesia and sedation scale was then used to compare the two groups. The patients in the PCA group were able to maintain a state of adequate analgesia without sleep with a significantly greater frequency than were those in the intramuscular injection group. On the basis of answers to a questionnaire given to the patient after 60 hours of morphine analgesia, it was apparent that the PCA group was much more satisfied with that form of postoperative analgesia. It would appear that PCA is an efficacious and safe method of providing for postoperative pain relief.

Patient‐controlled analgesia: can client education improve outcomes?

“…Owen et al (1990) sought to discover whether patients administered a similar amount of morphine via a PCA bolus dose, independently of a background infusion The only mention of preoperative information given to patients about the use of the PCA device m these studies was that it was given at the time of consent Information content was not disclosed The results demonstrated that, despite a standard background infusion and matching of the patients mto three groups with each group able to demand a different bolus size, no relationship between doses occurred There was no relationship between size of dose and demand rate for the first 24 hours followmg surgery This finding agrees with that of Bennett et al (1982a), and conhasts with the widely held view that patients make sufficient demands to mamtam their blood opiate concenhation above the minimum effective analgesic concentration…”

“…The area of stmctured preoperahve teachmg of pahents m the use of PCA devices and what is expeded of them needs further mveshgahon The implications m terms of reduced analgesic consumphon and improved well-bemg refleded m a reduced expenenc* of postoperahve pam cannot be exaggerated to both the nurse and the patient Summary of selected researdi findings Bennett et al (1982a) A wide vanation in drug use via PCA Owen et al (1990) Pahents do not make suffiaent demands of a P C A to maintam a mimmum effechve analgesic concentrahon Rogers et al (1990) High PCA drug use, compared to tradihonal regimes Sechzer (1971) High demand for analgesic via PCA ummediately post surgery Snwatanakul et al (1983) Nurses administer less than maximum prescnbed analgesic…”

“…, ,r> 1 well-bemg of their patients postoperahvely, by reducmg analgesic, if they need it (Dunwoody 1987 , \ j j j lu u / ĉ , "_. : " ,. / , ' , , analgesic demand and reducing the pahent s expenence of Most PCA devices allow tor a background tntusion ot analgesic and/or a pahent-tnggered bolus infusion The amount of drug and lockout mterval when a pahent cannot receive a bolus infusion is detemimed by the prescnbmg VARIABILITY OF ANALGESIC DEMAND doctor when the system is set up However, the madiine y^e amount of dnig used via PCA m the postoperahve allows for recaltbrahon at any hme p^^ has been shidied by Bennett et al (1982a), Graves et Tbs hterahire review sets out to seek answers to the ^; (1933) i^^^ ^ «/ (1990), Owen et al (1990) and followtng queshons would speafie, struetured preopera-Roaersetal (19W) hve tnstniehon by nurses wtth pahents, eoneemtng the ^^^^^ ^ ^; ^93^3) perfonned two shidies In the first, use and purpose of the PCA device (a) reduce the amount ^ pj^^ ^^jy ^^ey exammed dmg use via PCA m seven surgery to evaluate a mean hourly drug consumption on a deniand-only basis The hourly and total drug amounts used by each patient were coUected from tfie pump's visual display They found that there was a tenfold vanation m the amount of drug (morphine) that the patients selfadministered m the first 36 hours following surgery This vanahon remamed, even after correction for body weight Rogers et al (1990) performed a prospeehve study of 69 patients divided randomly into 34 using PCA and 35 receiving the traditional mframuscular method of analgesic debvery Preoperahve mstruchon on the use of the PCA device was given by pharmacy personnel the mght before surgery A wide range of analgesic use in the first 24 hours was reported, with the highest amongst the PCA group The condusions m the study by Snwatarwkul et al (1983) provide one explanahon for this finding Sechzer (1971) descnbes a high mitial demand for analgesic m the postoperahve penod, which provides another explanahon for the findings Owen et al (1990) studied the widely held view that, given the choice, pahents would make suffiaent demands of the PCA to maintain their blood opiate level above the mmimum efiFective analgesic concenfration They used 45 pahents in the study, each received a background infusion of 15 mg/hour of morphine Three groups of 15 patients each were prescnbed demand bolus doses of 0 4mg, 0 7 mg or 1 mg of morphine, with a 3-mmute lockout interval The groups were simdar m age, weight and operative procedure…”

Patient‐controlled analgesia (PCA): does time saved by PCA improve patient satisfaction with nursing care?

“…The efficacy of PCA The considerable body of literature regarding PGA (for example, Slattery et al 1983, Tamsen 1985, Notcutt & Morgan 1990, Thomas et al 1990, Thomas 1991 confiims that supenor analgesia can be provided This is due to the fact that PGA overcomes the problem of marked differences m the pharmacokmetics and pharmacodynamics of narcotics in individual patients Because they are able to maintain a near constant level of narcotic, patients avoid penods of severe pam and sedation that come with the peaks and troughs of narcotic level m the traditional p r n protocol Glimcal benefits of PGA also include fewer respiratory complications (Bennett et al 1982), earlier ambulation (Bollish et al 1985) and a reduction m the length of post-operative hospitahzation (Keen-Szanto 1984, Glark ef a/ 1989, Thomas et ai 1990, Thomas 1991 However, successful use of PGA also depends on psychological vanables such as locus of control, coping style and levels of anxiety which can mfiuence the patient's ability to press the button, l e self-administer pam medication (see Thomas 1991 for a fuller discussion)…”

Dimensions of pain and analgesic administration associated with coronary artery bypass grafting in an Australian intensive care unit

“…Pain from chest drains and surgical incisions has been cited by 45% of cardiac surgical addition, nurses' assessment of pain will influence their own practice in administering analgesics. Therefore it is patients as the worst memory of their stay in ICU (Paiement et al 1979). Suction of the ET tube has been shown to important to establish not only how accurate nurses are in assessing patients' pain in this environment but also the cause distress (Paiement et al 1979) and to increase the severity of incisional pain (Puntillo 1990).…”