In the Restart PCA Group, 37 patients (97.4%) wished to have IV PCA restarted because they felt that IV PCA would be more effective compared with the rescue IM opioid (Table 3). In the Nonrestart PCA Group, the common reasons included minimal or no pain (51.9%), inconvenience of the PCA machine (15.6%), ineffective analgesia by IV PCA (11.7%), side effects during PCA (11.7%), and wishing to tolerate pain (7.8%).
All except two patients in the Restart Group had been started on regular oral paracetamol for more than 1 day before cessation of PCA. More patients in the Restart PCA Group complained of worse pain during the 24-h period (60.5% vs 16.9%) (P < 0.0001), and required more rescue IM opioid (36.8% vs 11.7%) (P = 0.001). The restart PCA group tended to have higher 24-h median VAS pain scores than the Nonrestart PCA Group at rest (3.3 vs 2.0) and during mild (5.0 vs 4.0) and moderate activities (8.0 vs 6.0). However, the differences were not statistically significant.
The total morphine consumption, average daily consumption, and morphine consumption in the 24 h before cessation of PCA were different between the two groups (Table 1).
Our survey revealed that 36 patients (31.3%) from both groups complained of more pain during the 24-hour period after cessation of PCA. One-third of these patients claimed unsatisfactory pain control and wished to have IV PCA restarted. Almost all patients who preferred to restart PCA felt that IV PCA would have been more effective. However, this reason could not be explained by the patients’ unsatisfactory experience with IM opioids. Only 37% of the patients actually received rescue IM opioids during the 24 hours after cessation of PCA. Patients who did not receive IM opioids would not have experienced whether the rescue analgesia would have been effective. Perhaps if they were given the injections, they may have experienced satisfactory relief for their pain. Most patients had the expectation that the alternative rescue IM analgesia would be less satisfactory after their positive experience with IV PCA. This may reflect the advantages offered by IV PCA including expediency and the feeling of being in control.
The different types of surgery, VAS pain scores at the time of cessation of PCA, and side effects may influence the patients’ preference whether to restart PCA. However, there was no statistical difference between the two groups with respect to type of surgery, VAS pain scores, PCA side effects at the time of cessation, age, sex, and the number of PCA days. The VAS pain score at the time of cessation of IV PCA also did not predict pain severity and patient satisfaction with the alternate treatment afterwards. There have been previous reports that reasons other than pain relief may influence patient satisfaction (4,5).
In this survey, approximately half of patients did not wish to restart PCA because they were satisfied with their pain relief over the 24 hours post-PCA (Table 3). However, when persistent pain was present after cessation of PCA, some patients did not want IV PCA restarted. Twelve patients (15.6%) did not like the PCA machines (Graseby 3300; Graseby Medical Ltd., Watford, Herts, UK) because they were too cumbersome and restrictive. This problem has been reported in other centers (3,6). Some patients, surgeons, and physiotherapists regard the PCA machine as restricting patient mobility, rather than facilitating early mobilization. In addition, the incorrect belief that patients receiving PCA should not be mobilized has persisted despite continuing education. The use of ambulatory PCA devices may be more acceptable and resolves this misconception.
Other reasons for not wishing to restart IV PCA were less common. Ineffective pain relief and side effects of PCA opioids were expressed by 23.4% of the Nonrestart PCA patients. Regular reviews of patients receiving PCA are mandatory for early detection and treatment of unsatisfactory pain relief and side effects (7). Although the role of preoperative education and training in the use of PCA is unclear, it is nevertheless important to explain to the patients about the concept and usage of PCA. Individual patients have different beliefs, misconceptions and misunderstandings regarding the use of PCA (6). One patient in the Restart PCA Group made his decision based on his misunderstanding that PCA would alleviate nausea. Some patients did not wish to be restarted on IV PCA because they preferred to tolerate the pain. The wish to tolerate pain is influenced by psychosocial factors, including cultural and racial background, past experience, and the emotional and psychological make-up of individual patients.
In this survey, the reasons for cessation of PCA were similar in the Restart and Nonrestart PCA Groups. Low pain scores and patients’ request to cease PCA were the most common reasons for cessation of PCA. The latter reason usually related to a dislike of being “tied-up” and the fact that the PCA device hindered mobilization. Uncomfortable side effects, most commonly dizziness, nausea, and vomiting, were also frequently the reasons to cease PCA. The decision to stop PCA on the basis of these reasons often resulted in patients opting for PCA later when they discovered that similar side effects are experienced with IM opioid. Careful explanation and reassurance may improve use and patient’s acceptance of PCA and avoid a premature decision to cease IV PCA. All patients should also be followed-up after the cessation of PCA to assess the efficacy and side effects of subsequent pain treatment.
Although pain scores and other clinical reasons for terminating PCA were not predictive of who will wish to restart IV PCA, morphine consumption was useful. In the group who wished to restart PCA, the 24-hour PCA morphine use before stopping PCA, mean daily and total morphine consumption were increased. It is uncertain whether this reflects a decreased pain threshold in this group of patients and warrants more aggressive alternative pain management after cessation of PCA. It is not likely that pain is more severe in patients with larger morphine consumption at the time of ceasing PCA, as the VAS pain scores were similar between the two groups. Further prospective evaluation of the appropriate morphine consumption levels that may be predictive of the correct decision to cease IV PCA should be considered.
Our study was limited by the number of patients surveyed and the unequal sample sizes in the two groups. The main concern with unequal sample sizes was the inequality of the variances of the two groups that would affect the statistical method. However, variances of the two groups in morphine consumption were similar, thus, supporting the validity of the statistical analysis. The survey might also be affected by several factors that were not controlled in the study and might result in selection bias. The type of surgical procedure may produce pain of differing severity, and hence affect analgesic requirement. There was, however, no statistical difference between the two groups in this respect. Most patients also started receiving oral paracetamol 1–3 days before the cessation of PCA. Similarly, the nonuniform duration of oral analgesic consumption before the cessation of PCA may also influence the need for differing amounts of analgesia in the post-PCA period. In addition, we did not evaluate preoperative pain that may have contributed to the difference in analgesia requirement in the postoperative period. A recent report found that the intensity of preoperative pain directly correlated with the amount of morphine needed for postoperative analgesia (8).
The clinical decisions to cease IV PCA do not predict patient acceptance of and satisfaction with subsequent pain treatment. In this survey, one-third of the patients at 24 hours after cessation of PCA wished to restart IV PCA. The only factor that determined whether the patient was content with the cessation of PCA was the IV PCA morphine consumption. Patients who required <15 mg of morphine in the previous 24 hours could accept cessation of PCA. However, for various reasons, some patients preferred not to restart IV PCA despite considerable pain.
Pain is an individual experience. Pain management, including the cessation of PCA, should be individualized. Perhaps further patient education at the time of cessation of PCA may also improve patient acceptance and satisfaction. Some patients may benefit from subsequent APS follow-up after cessation of PCA.
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© 2001 International Anesthesia Research Society
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