***TASK*** the task is to summarize an input biomedical literature in six sentences 
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    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
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    Input: Background :  Pain after coronary artery bypass surgery persists for several days . A continuous intravenous infusion of an opioid adequately accomplishes good pain control in the intensive care unit , but it is often not suitable on the ordinary ward . Patient‐controlled analgesia ( PCA ) with intermittent injections delivered by one of the new devices now available could be an alternative to conventional nurse‐controlled analgesia ( NCA ) based on intermittent injections . The aim was to compare these two techniques with respect to efficacy and the amount of opioid used The purpose of this comparative study was to examine differences in pain intensity , sleep disturbance , sleep effectiveness , fatigue , and vigor between patients undergoing cholecystectomy who received either patient-controlled analgesia ( PCA ) or intramuscular ( IM ) injections of narcotics for postoperative pain . The PCA group consisted of 16 women , aged 22 - 58 ; the IM group consisted of 10 women , aged 22 - 60 . Data were collected on patients ' postoperative days 1 and 2 . Findings indicated that patients receiving PCA reported less pain on postoperative day 1 and less fatigue on postoperative day 2 than patients receiving IM injections of narcotics BACKGROUND In previous studies comparing patient-controlled-analgesia and intramuscular pain management have been unable to provide conclusive evidence of the benefits of either method of postoperative pain control . AIM The purpose of the study was to compare the efficacy and cost-effectiveness of intravenous patient-controlled-analgesia with intermittent intramuscular morphine for Chinese women in the first 24 hours following elective gynaecological surgery . METHODS A r and omized control design was used . The main outcomes were level of pain and cost for the two types of pain management . Participants indicated their level of pain at rest and when deep breathing or coughing on a 100 mm Visual Analogue Scale , on seven occasions within 24 postoperative hours . Costs for the two types of pain management were based on the costs of equipment , drugs and nursing time . RESULTS A total of 125 women participated in the study .  Mean pain level over the 24 hours in the patient-controlled-analgesia group was significantly lower than in the intramuscular group ( P < 0.001 ) . Mean pain level over the seven occasions for the patient-controlled-analgesia group was 11.83 points ( 95 % CI 7.14 - 16.52 ) lower when at rest and 11.73 points ( 95 % CI 5.96 - 17.50 ) lower during motion than the intramuscular group . Cost per patient was $ 81.10 ( Hong Kong ) higher for patient-controlled-analgesia than for intramuscular pain management . Women in the patient-controlled-analgesia group had significantly greater satisfaction with pain management than those in the intramuscular group ( P < 0.001 ) , but reported significantly more episodes of nausea ( P < 0.05 ) . CONCLUSIONS While patient-controlled-analgesia was more costly , it was also more effective than conventional on-dem and intramuscular opioid injections after laparotomy for gynaecological surgery Background and Objectives : To compare the use of patient-controlled analgesia to intermittent intramuscular injections of morphine following major gynecological laparoscopic procedures in order to assess differences in level of pain , sedation , episodes of nausea and /or vomiting , hospitalization time and patient satisfaction with their postoperative analgesia . Methods : Seventy-two patients undergoing major gynecological laparoscopic surgery were r and omized to receive either postoperative analgesia via intermittent intramuscular injection of morphine ( Group 1 ) or patient controlled analgesia ( PCA - Group 2 ) . All patients received anesthesia via a st and ardized protocol . Postoperative pain levels were recorded via a 10 cm visual analogue scale , and sedation scores were recorded on a st and ard PCA form . Episodes of nausea and vomiting were also recorded on the same form . Results : There were no statistically significant differences between intramuscular analgesia and PCA for any of the factors studied . Most significantly it was found that most patients ceased to require either form of parenteral analgesia within 24 hours of their procedure , regardless of the operating time . Conclusion : It is important for the surgeon to be aware of the effects of postoperative analgesia on his or her patients ' level of satisfaction . We do not recommend the use of PCA analgesia following major laparoscopic gynecological surgery After open prostatectomy , 52 patients were r and omly allocated to two treatment groups . Group A ( 26 patients ) received buprenorphine sublingually , and in group B ( 26 patients ) the analgesia was induced using a patient-controlled analgesia system with morphine . The total dose of morphine given during the first 24 h was 72 + /- 8 mg compared to 1.6 + /- 0.45 mg of buprenorphine . The total dose of buprenorphine  on days 2 and 3 was significantly lower than the total dose of morphine ( p < 0.01 ) . There were no significant differences in visual pain scores , side effects , mean arterial blood pressure , pulse rate and respiration rate between the two groups . Sublingual application of buprenorphine offers an effective and easy alternative to the parenteral route of morphine for the management of postoperative pain A r and omized , controlled clinical trial was conducted on 66 patients undergoing elective cardiac surgery to compare patient-controlled analgesia ( PCA ) to nurse-controlled analgesia ( NCA ) with continuous morphine infusion . Hourly assessment of pain ( at rest and on movement ) using a visual analogue scale ( VAS ) , of respiratory rate , and level of sedation took place for the 24 h following extubation . The incidence of nausea was also recorded . Mean pain scores were calculated , and peak pain and sedation scores , together with lowest respiratory rates , were identified .  Morphine consumption was measured at 24 h. No significant differences were found between the groups ' scores for pain or sedation . The PCA group had significantly lower respiratory rates ( P = 0.02 ) and a lower incidence of nausea ( P = 0.008 ) . The PCA group also consumed significantly more  morphine  ( P = 0.0001 ) . The study suggests a beneficial effect from PCA after cardiac surgery in reducing nausea , compared to NCA . It confirms nurse-controlled infusion analgesia as an effective form of pain relief in an intensive care and high-dependency setting Intranasal administration of lipophilic opioids has been shown to be an effective method of administration which is devoid of major side‐effects . Whether it is as effective as intravenous administration for patientcontrolled analgesia ( PCA ) has been investigated for fentanyl and pethidine , but not for diamorphine . This study reports a r and omised controlled trial design ed to compare the effectiveness of diamorphine administered as PCA utilising either the intranasal or intravenous routes . We investigated 52 consecutive patients undergoing primary lower limb joint replacement surgery . Patients were r and omly allocated to receive PCA diamorphine , administered either intravenously ( 0.5 mg bolus , 3 min lockout ) or intranasally ( 1.0 mg bolus , 3 min lockout ) . Pain was assessed using a Visual Analogue Score ( VAS ) at rest and on movement on five occasions over the first 36 h postoperatively . The results demonstrated that patients in the intranasal PCA group had significantly higher VAS scores than the intravenous group , both at rest ( intranasal median 35.5 vs. intravenous median 20 ; p = 0.030 ) and on movement ( intranasal median 64 vs. intravenous median 50 ; p = 0.016 ) . However , significantly fewer patients in the intranasal group compared with the intravenous group suffered episodes of vomiting ( intranasal 0/24 vs. intravenous 6/24 patients ; p = 0.022 ) . We suggest that if a maximal reduction in pain score is considered the goal of PCA management , the intravenous route is preferable to the intranasal route We have evaluated the level of state and trait anxiety , neuroticism , extroversion and coping style as predictors of the effectiveness of patient-controlled analgesia ( PCA ) in 110 patients undergoing total abdominal hysterectomy . After operation patients were allocated to receive pain control with either PCA or i.m . injections ( IMI ) .  Pain was assessed using the short form McGill pain question naire at 6 , 18 and 24 h after operation , and by recording the amount of analgesic consumed in the first 24 h after surgery . Both state anxiety and coping style were significant predictors of postoperative pain , irrespective of the method of analgesia used . Patients using PCA experienced significantly better pain control than those receiving IMI . However , it was those with high levels of state anxiety who experienced the greatest reduction in pain with PCA . In addition to achieving better pain control , patients who received PCA used significantly less analgesia and were discharged earlier than patients who received IMI We have compared patients ' and nurses ' assessment s of postoperative pain and anxiety after different analgesic treatments . Sixty orthopaedic patients were allocated r and omly to receive i.v . piritramide ( either nurse-controlled or patient-controlled ) or subarachnoid bupivacaine ( nurse-controlled or patient-controlled ) . Patients and nurses assessed pain and anxiety using a visual analogue scale ( VAS ; 1 - 100 mm ) . Pain and anxiety ratings of patients and nurses were significantly correlated ( Spearman 's r > or = 0.69 ; P < 0.001 ) . In general , patients ' pain scores were higher than nurses ' scores ( patients ' median VAS = 34 ( range 1 - 76 ) mm ; nurses VAS 21 ( 1 - 59 ) mm ) and for all groups except the patient-controlled subarachnoid bupivacaine group , where they were significantly higher ( P < 0.01 ) . Discrepancy in pain estimates between patients and nurses increased with the level of pain . The relationship between patients ' and nurses ' anxiety scores was less clearly defined and did not depend on the level of anxiety OBJECTIVES To assess the economics of  patient-controlled analgesia ( PCA ) treatment versus regular intramuscular ( i.m . ) injections of opioid analgesia  for pain management after hysterectomy . METHODS Cost-minimization analysis was used based on the comparable pain control results achieved in the two treatment groups . Observations were taken of treatment-related events with personnel ( mostly nursing ) time implication s during the trial . Times were then associated with these events in an independent study of personnel activity . Costs were linked by using average wage rates for the various personnel for the Montreal area during the time of the study . Drug and material costs were hospital acquisition costs for all items . The cost of the PCA  pump itself was not included in the analysis . Several analyses were performed to test the sensitivity of the results to various assumptions . RESULTS The results for total costs of the two therapies generally showed PCA to be more costly than regular i.m . injections despite no costs of the pump being included in the analyses . These results were robust with respect to changes in assumptions . Even when intentionally biasing the analysis against i.m . therapy , it was difficult to obtain results that favored PCA . CONCLUSIONS Based upon the institutions and assumptions in this analysis , PCA offers no cost advantages over regular i.m . therapy in the pain management after hysterectomy . Regular i.m . injections provided less costly analgesia This prospect i ve , r and omized study compared the effects of two methods of morphine administration after abdominal surgery in 62 adults . All patients were offered intravenous morphine in the Postanesthesia Care Unit . On the ward , one group ( PCA-CI ) received a continuous infusion of morphine that could be supplemented by a patient-controlled bolus every 10 minutes . The other group ( IM ) received intramuscular morphine ( 0.08 - 0.12 mg/kg ) as often as every 3 hours when requested . During three postoperative interviews , patients were question ed about pain relief ( visual analogue scale ) , adverse opioid effects , and satisfaction with the method of analgesia . Total dose of morphine  ( mg , mg/kg body weight ) , time to first oral analgesic medication , length of hospital stay , and cost were calculated following discharge . There was a wide interindividual variation in reported pain intensity and morphine usage in both groups . Comparison of both groups demonstrated no significant differences in analgesia , incidence of adverse opioid effects , 24 and 36 hour morphine dose , time to first oral analgesic medication , operating cost , and length of hospital stay . Patients in the PCA-CI group received a slightly greater dose of morphine in relation to body weight ( 24 hr , P = 0.03 ; 36 hr , P = 0.05 ) and reported a greater degree of satisfaction at each assessment ( P = 0.005 , P = 0.02 , P = 0.01 ) . These data support the greater patient satisfaction associated with patient-controlled analgesia but suggest that the wide range of reported pain scores and morphine requirements makes it difficult to demonstrate , in a small population , superior pain relief from patient-controlled analgesia when nurses are encouraged to administer intramuscular pain medication more effectively The postoperative analgesia afforded after colonic surgery by IV opioid , clonidine and lignocaine given intra- and postoperatively was evaluated . In a double-blind r and omised trial , 80 male patients scheduled for colonic resection under general anaesthesia received fentany 15 μg.kg−1 at induction and another 4 μg.kg−1 before skin inc 
    Output:
    
PCA provided better pain control and greater patient satisfaction than conventional parenteral ' as-needed ' analgesia .
Patients using PCA  consumed higher amounts of opioids than the controls and had a higher incidence of pruritus ( itching ) but had a similar incidence of other adverse effects .
There was no difference in the length of hospital stay .
AUTHORS ' CONCLUSIONS This review provides evidence that PCA is an efficacious alternative to conventional systemic analgesia for postoperative pain control