Differences in Postoperative Opioid Consumption in Patients Prescribed Patient-Controlled Analgesia Versus Intramuscular Injection

Analgesic effects of piritramide in acute postoperative pain - comparison of intramuscular administration with patient-controlled intravenous analgesia and impact of OPRM1 and ABCB1 polymorphisms

AIMS

The aim of this study was to compare the efficacy, consumption and safety after piritramide administered either intramuscularly (IM) on demand or via patient-controlled intravenous analgesia (PCA) and to examine the impact of OPRM1 and ABCB1 gene polymorphisms on the drug efficacy/safety in both regimens.

METHODS

One hundred and four patients scheduled for elective inguinal hernioplasty received piritramide with PCA or IM for postoperative pain management. We evaluated piritramide consumption, pain intensity using visual analogue scale (VAS) and adverse effects.

RESULTS

Median (IQR) piritramide consumption was 18.5 (13.5-31.2) and 15.0 (15.0-15.0) mg in the PCA and IM groups, respectively (P=0.0092). The respective values of area under the VAS_2-16-time curve were 40 and 280 mm.h (P=0.0027). Opioid-induced adverse effects were more frequent in the PCA than in the IM group. Variant OPRM1 allele was associated with decreased pain relief, increased opioid consumption and increased incidence of adverse effects, while ABCB1 polymorphisms showed no impact on the observed parameters.

CONCLUSIONS

We observed higher piritramide consumption, better pain relief and slightly worse safety profile in the PCA group compared with IM administration. Variant OPRM1 118G allele carriers required higher opioid dosing and suffered from more adverse effects, however, the differences between genotypes have been less pronounced in the PCA patients likely due to improved pain management via PCA.

Patient controlled analgesia: The impact of an 8 versus 10 minute lockout interval in postoperative patients

The purpose of this study was to compare the level of pain control achieved with 8 versus 10 minute lockout intervals in adult patients who received patient controlled analgesia (PCA) within 24 hours of surgery. There was no difference in pain in the first 72 hours between the 8 minute and 10 minutes group. Additionally, there was no difference in time to first PCA regimen change or a composite outcome of adverse events.

Integration of pain scores, morphine consumption and demand/delivery ratio to evaluate patient-controlled analgesia: the C-SIA score

Background

Patient-controlled analgesia (PCA) is used to manage postoperative pain. Postoperatively, some patients need to be re-instructed on its correct use. This study explores the efficacy of re-instruction and illustrates a comprehensive version of the Silverman integrated approach (C-SIA), based on the integration of static and dynamic pain scores, morphine consumption, and the ratio between demanded and delivered PCA boluses (the DD ratio).

Methods

In total, 50 patients operated on for colorectal surgery were studied retrospectively. The change in DD ratio after re-instruction was analyzed as the primary endpoint. Re-instructed and not re-instructed subjects were compared according to DD ratio, pain scores, and morphine consumption. A secondary comparison was performed using the SIA and C-SIA scores, to illustrate the reliability of the latter tool. Agreement between C-SIA and SIA score was assessed using a Bland-Altman analysis.

Results

In re-instructed patients, the DD ratio decreased after re-education (P = 0.011). Re-instructed patients had higher DD ratios (P = 0.018) and pain scores at rest (P = 0.024) and movement (P = 0.012) at 24 h after surgery than not re-instructed subjects. These differences disappeared at the 48 h visit. Both the SIA and C-SIA scores reflected these findings. C-SIA scores showed a higher coefficient of correlation with the DD ratio (r = 0.815; P < 0.001) than SIA scores (r = 0.663; P < 0.001). The C-SIA scores, in absolute values, being based on more variables, were, on average, 2.5 times the SIA score.

Conclusions

Re-instruction is effective for optimizing PCA therapy. The C-SIA is an alternative to the SIA score that gives an overall measure of PCA therapy efficacy.

Pre-operative pain sensitivity: A prediction of post-operative outcome in the obstetric population

CONTEXT

Experimental assessments can determine pain threshold and tolerance, which mirror sensitivity to pain. This, in turn, influences the post-operative experience.

AIMS

The study intended to evaluate whether the pre-operative pressure and electrical pain tests can predict pain and opioid requirement following cesarean delivery.

SETTINGS AND DESIGN

Research was conducted on females scheduled for cesarean section at a tertiary care hospital of the state. Twenty women were enrolled, after obtaining written informed consent.

MATERIALS AND METHODS

PAIN ASSESSMENT WAS PERFORMED ON THE EVE OF CESAREAN SECTIONS USING THREE DEVICES: PainMatcher(;) determined electrical pain threshold while the algometers PainTest(™) FPN100 (manual) and PainTest(™) FPX 25 (digital) evaluated pressure pain threshold and tolerance. Post-operative pain relief included intravenous morphine administered by patient-controlled analgesia, diclofenac (100 mg, every 12 h, rectally, enforced) and paracetamol (1000 mg, every 4-6 h, orally, on patient request). Pain scores were reported on numerical rating scales at specified time intervals.

STATISTICAL ANALYSIS USED

Correlational and regression statistics were computed using IBM SPSS Statistics 21 software (IBM Corporation, USA).

RESULTS

A SIGNIFICANT CORRELATION WAS OBSERVED BETWEEN MORPHINE REQUIREMENT AND: (1) electrical pain threshold (r = -0.45, P = 0.025), (2) pressure pain threshold (r = -0.41 P = 0.036) and (3) pressure pain tolerance (r = -0.44, P = 0.026) measured by the digital algometer. The parsimonious regression model for morphine requirement consisted of electrical pain threshold (r(2)= 0.20, P = 0.049). The dose of morphine consumed within 48 h of surgery decreases by 0.9 mg for every unit increment in electrical pain threshold.

CONCLUSIONS

The predictive power of pain sensitivity assessments, particularly electrical pain threshold, may portend post-cesarean outcomes, including opioid requirements.

Patient satisfaction about using patient controlled analgesia in managing pain post surgical intervention

Management of postoperative pain using patient controlled analgesia (PCA) has increased for its proven advantages over conventional methods of pain control. The purpose of this study was to investigate patients' satisfaction about using PCA post surgical intervention among patients at Saudi health care settings. A cross-sectional, descriptive correlational design was used to collect data from patients using PCA post surgical interventions. The analysis showed that patients had a moderate to high level of perception about efficacy of PCA, and had a moderate level of knowledge about PCA use and its function. The duration of using a PCA pump, patients' age, gender, marital status, educational level, type of surgery, and their work status were significant predictors (F 7, 76 = 5.13, p < .001; R(2) = 0.59). PCA offers patients with an individualized analgesic therapy that meets the patients' demand of pain control. The implications for nurses and medical staff are discussed.

Aging and delirium: too much or too little pain medication?

Review of the literature revealed an association of pain and delirium in hip fracture patients. The literature was sparse addressing other types of patients. The purpose of the present study was therefore to examine the association of pain and delirium in medical and surgical patients. A retrospective record review was conducted using records of 100 patients who developed delirium while hospitalized. Data included: age, comorbidities, hospital day when delirium developed, presence of major risk factors for delirium on admission, and amount of medication received in the 24 h before onset of delirium. Descriptive statistics, correlations, and univariate analysis of variance were used to determine association between the variables. The mean age was 76.71 years. The mean number of comorbidities was 2.22. The mean number of risk factors for delirium on admission was 2.26 (range 0 to 5). The mean percentage of total amount of medication ordered that was received was 27.67%. Those individuals admitted with a risk factor of hearing loss received significantly less amount of pain medication than those with other risk factors (p = .023). Nurses should carefully assess pain management in their older patients. If using a PCA pump, the older patient's ability to manage the pump should be reassessed often. If a patient is admitted with risk factors for development of delirium, unmanaged pain might be the additional factor that precipitates delirium.

Randomized trial comparing 3 methods of postoperative analgesia in gynecology patients: patient-controlled intravenous, scheduled intravenous, and scheduled subcutaneous

OBJECTIVE

The objective of the study was to determine whether any of 3 routes of opioid administration (patient-controlled analgesia [PCA], scheduled intermittent intravenous [i.v.], or scheduled intermittent subcutaneous [s.q.]) provides superior pain relief and satisfaction among patients undergoing abdominal gynecologic surgery.

STUDY DESIGN

Patients were randomized to intravenous hydromorphone by PCA, i.v. hydromorphone via scheduled nurse-administered doses, or s.q. hydromorphone via scheduled nurse-administered doses. Self-reported pain and satisfaction were recorded over 48 hours following arrival at the nursing unit. Linear mixed effects modeling was used to compare outcomes among the groups.

RESULTS

Neither pain scores nor satisfaction differed by group. PCA patients had higher total opioid use (P < .0001) and a higher rate of pruritus (P = .04).

CONCLUSION

Given these findings as well as those in previous literature, no specific method of postoperative analgesia appears to be superior.