Intravenous acetaminophenvs oral ibuprofen in combination with morphine PCIA after Cesarean delivery

Upper back, neck, and shoulder pain during labor epidural analgesia: a quality improvement initiative

BACKGROUND

Severe upper back/interscapular, neck and shoulder pain during labor epidural analgesia (PLEA) is not uncommon. The objective of this quality initiative was to evaluate the incidence, demographic associations and management of PLEA.

METHODS

An eight-month, single-center quality improvement initiative was performed for the detection and management of PLEA. After survey-based consensus among obstetric anaesthetist attendings and fellows, a three-step PLEA treatment protocol with interventions and numeric rating scale (NRS, 0 - 10 scale) pain assessments was introduced. Demographic data and outcomes were compared among parturients with and without PLEA.

RESULTS

Among 2888 women who received labor epidural analgesia from October 2022 through May 2023, 36 (1.2% [95% CI 0.9% to 1.7%]) reported PLEA. Women with PLEA were younger, more likely to be nulliparous, and had a higher body mass index (BMI) than women without PLEA (p < 0.05 for all). A total of 72.2% (26/36) of women with PLEA received at least one protocol treatment. Twenty-three women received first-line therapy, with pain relief in 91.3% (21/23). The median NRS score decreased from 9 [IQR 8-10] to 3 [1-4]. Women with PLEA had a higher incidence of cesarean delivery (CD) and a longer interval between epidural placement and delivery; 52.8 vs. 17.5% (p < 0.001) and 16.5 vs. 6.9 hours (p < 0.001), respectively.

CONCLUSIONS

The incidence of PLEA was higher than previously reported. Patients with PLEA were younger, more commonly nulliparous, had higher BMI, longer epidural infusion times and higher CD rates. A three-step treatment protocol was successful in managing PLEA.

Intravenous Acetaminophen Does Not Provide Adequate Postoperative Analgesia in Dogs Following Ovariohysterectomy

Simple Summary

Acetaminophen is the most commonly used pain relief (analgesic) agent in humans worldwide and its use is becoming more frequent in dogs. However, limited evidence supports this use. This study aimed to investigate the analgesic effect of acetaminophen when administered as an intravenous injection post-operatively in female dogs. A total of 34 dogs were randomly divided into two groups and either administered acetaminophen or saline intravenously immediately after desexing. The dogs had their pain levels evaluated at 10, 20, 40, 60, 120, and 180 min after awakening from general anesthesia and the pain levels between groups were compared. Concurrently, the dogs had blood collected at 2, 5, 10, 40, and 80 min following injection of the acetaminophen. The blood was analyzed to quantify the levels of acetaminophen in the body. This study found that acetaminophen was no better than saline in providing analgesia in dogs following surgery. This study suggests that acetaminophen used alone may not be an appropriate post-operative analgesic agent for desexing procedures.

Abstract

(1) Objective: To investigate the analgesic effects of intravenous acetaminophen after intravenous administration in dogs presenting for ovariohysterectomy. (2) Methods: 14 ASA I client-owned female entire dogs. In this randomized, blinded, clinical study, dogs were given meperidine and acepromazine intramuscularly before induction of anesthesia with intravenous propofol. Anesthesia was maintained with isoflurane in oxygen. Intravenous acetaminophen 20 mg/kg or 0.9% NaCl was administered postoperatively. Pain assessments were conducted using the Glasgow Pain Scale short form before premedication and at 10, 20, 60, 120, and 180 min post-extubation or until rescue analgesia was given. The pain scores, times, and incidences of rescue analgesia between the groups was compared. Blood was collected before and 2, 5, 10, 20, 40, and 80 min after acetaminophen administration. Acetaminophen plasma concentration was quantified by liquid chromatography-mass spectrometry. The acetaminophen plasma concentration at the time of each pain score evaluation was subsequently calculated. (3) Results: There was no significant difference in pain scores at 10 min, highest pain scores, or time of rescue analgesia between groups. In each group, 3 dogs (43%) received rescue analgesia within 20 min. (4) Conclusions: Following ovariohysterectomy in dogs, there was no detectable analgesic effect of a 20 mg/kg dosage of intravenous acetaminophen administered at the end of surgery.

The Current Consideration, Approach, and Management in Postcesarean Delivery Pain Control: A Narrative Review

Optimal postoperative analgesia has a significant impact on patient recovery and outcomes after cesarean delivery. Multimodal analgesia is the core principle for cesarean delivery and pain management. For a standard analgesic regimen, the use of long-acting neuraxial opioids (e.g., morphine) and adjunct drugs, such as scheduled acetaminophen and nonsteroidal anti-inflammatory drugs, is recommended unless contraindicated. Oral or intravenous opioids should be reserved for breakthrough pain. In addition to the aforementioned use of multimodal analgesia, preoperative evaluation is critical to individualize the analgesic regimen according to the patient requirements. Risk factors for severe postoperative pain or analgesia-related adverse effects will require modifications to the standard analgesic regimen (e.g., the use of ketamine, gabapentinoids, or regional anesthetic techniques). Further investigation is required to determine analgesic drugs or dose alterations based on preoperative predictions for patients at risk of severe pain. Outcomes beyond pain and analgesic use, such as functional recovery, should be determined to evaluate analgesic treatment protocols.

Evaluation of the Adding Paracetamol to Dexmedetomidine in Pain Management After Adult Cardiac Surgery

Background

Postoperative pain control after cardiac surgery is usually based on Opioids. These drugs are associated with side effects, and the use of drugs with fewer side effects is important for analgesia. Dexmedetomidine and paracetamol have fewer side effects than opioids.

Objectives

The aim of the study was to evaluate the adding paracetamol to dexmedetomidine continuous infusion pump for pain management after adult cardiac surgery.

Methods

In this study, 100 patients were divided into two groups. One group received a continuous infusion of dexmedetomidine and paracetamol (DP), and the other received dexmedetomidine (D). These two groups were evaluated for MAP, HR, and the need for prescribing opioids before and after extubation. Also, duration of intubation and pain before extubation and 36 hours after every 4 hours.

Results

Patients in the DP group had lower mean MAP and HR during intubation period than the D group and needed fewer opioids and doses of opioids in addition to drug study infusion pre- (P = 0.001) and post-extubation (P = 0.001 and P = 0.022, respectively). The DP group patients were extubated earlier (P = 0.001). After extubation, the DP group had less pain than the D group.

Conclusions

This study showed that adding paracetamol to the dexmedetomidine infusion pump can provide better analgesia.

Evidence for the Efficacy of an Opioid-Sparing Effect of Intravenous Acetaminophen in the Surgery Patient: A Systematic Review

BACKGROUND

Intravenous (IV) acetaminophen is used in multimodal analgesia to reduce the amount and duration of opioid use in the postoperative setting.

METHODS

A systematic review of published randomized controlled trials was conducted to define the opioid-sparing effect of IV acetaminophen in different types of surgeries. Eligible studies included prospective, randomized, double-blind trials of IV acetaminophen compared with either a placebo- or active-treatment group in adult (age ≥18 years) patients undergoing surgery. Trials had to be published in English in a peer-reviewed journal.

RESULTS

A total of 44 treatment cohorts included in 37 studies were included in the systematic analysis. Compared with active- or placebo-control treatments, IV acetaminophen produced a statistically significant opioid-sparing effect in 14 of 44 cohorts (32%). An opioid-sparing effect was more common in placebo-controlled comparisons. Of the 28 placebo treatment comparisons, IV acetaminophen produced an opioid-sparing effect in 13 (46%). IV acetaminophen produced an opioid-sparing effect in only 6% (one out of 16) of the active-control groups. Among the 16 active-control groups, opioid consumption was significantly greater with IV acetaminophen than the active comparator in seven cohorts and not significantly different than the active comparator in eight cohorts.

CONCLUSIONS

The results of this systematic analysis demonstrate that IV acetaminophen is not effective in reducing opioid consumption compared with other adjuvant analgesic agents in the postoperative patient. In patients where other adjuvant analgesic agents are contraindicated, IV acetaminophen may be an option.

The analgesic effect of tramadol combined with butorphanol on uterine cramping pain after repeat caesarean section: a randomized, controlled, double-blind study

PURPOSE

This study aimed to explore the effect of patient-controlled intravenous analgesia (PCIA) using tramadol combined with butorphanol on uterine cramping pain in women undergoing repeat caesarean section.

METHODS

A total of 126 patients, who were scheduled to undergo repeat caesarean section under spinal anesthesia, were included. PCIA using tramadol combined with butorphanol or sufentanil was randomly performed for postoperative pain control. Postoperative uterine cramping pain and wound pain within 48 h after surgery were evaluated. Postoperative analgesic consumption, early activity time, and length of hospital stay were also recorded and analyzed.

RESULTS

Uterine cramping pain intensity in women undergoing repeat caesarean section was significantly higher compared with their wound pain (P < 0.05). The mean visual analog scale (VAS) score for uterine cramping pain in the tramadol-butorphanol group was significantly lower than that in the sufentanil group at rest, and at 6 h and 12 h after surgery. VAS scores for uterine cramping pain during movement at 6 h, 12 h, and 24 h after surgery in the tramadol-butorphanol group were also significantly lower than that in sufentanil group (P < 0.05). There was no significant difference in VAS score for wound pain at the different time points between the tramadol-butorphanol and sufentanil groups (P > 0.05). Patient-controlled intravenous analgesia with tramadol accelerated early rehabilitation and decreased the length of hospital stay (P < 0.05).

CONCLUSION

PCIA using tramadol combined with butorphanol provided a better analgesic effect and accelerated postoperative rehabilitation compared with sufentanil, and may be an optimal analgesic strategy for women undergoing repeat caesarean section.

CLINICAL TRIAL REGISTRATION

The trial was registered at Chinese Clinical Trial Registry ( www.chictr.org.cn ) with ID: ChiCTR-1800014986.

Comparison of Intravenous Nalbuphine and Paracetamol on Maternal Hemodynamic Status, Neonatal APGAR Score, and Postoperative Pain given before Induction of General Anesthesia for Elective Cesarean Section

Background:

Stress response to endotracheal intubation and surgery is associated with exaggerated hemodynamic response and an increase in catecholamine levels which is deleterious to both the mother and fetus. We aimed to compare the effects of intravenous nalbuphine and paracetamol on maternal hemodynamic status, neonatal APGAR score, and postoperative pain using the visual analog scale for elective cesarean section under general anesthesia.

Study Design:

This was a prospective, randomized, double-blinded clinical study.

Materials and Methods:

Sixty full-term pregnant patients, belonging to the American Society of Anaesthesiologist physical status Classes I and II, scheduled for elective cesarean section under general anesthesia were enrolled for the study. The patients were randomly allocated into two groups of 30 patients each to receive paracetamol (15 mg.kg^{− 1}) in Group Pand nalbuphine (0.2 mg.kg⁻¹) in Group N before induction of general anesthesia. Maternal heart rate, blood pressure, and oxygen saturation were recorded before infusion of study drugs, after induction, after intubation, and during surgery across all periods. APGAR score of neonates was recorded by a pediatrician. Time to reach visual analogue score-1 was recorded.

Results:

Significant attenuation of maternal hemodynamic response was observed with nalbuphine compared to the paracetamol group (P < 0.05). The time to achieve visual analogue score-1 in the postoperative period was higher in the nalbuphine group. APGAR score at 1 min was significant between the groups and at 5 min, nonsignificant difference was observed (P > 0.05).

Conclusion:

Nalbuphine and paracetamol are effective in perioperative hemodynamic stability of mother and APGAR score of neonates. However, nalbuphine had better hemodynamic stability as compared to paracetamol with a comparable APGAR score at 5 min.

The analgesic efficacy of IV acetaminophen for acute postoperative pain in C-section patients: a randomized, double-blind, placebo-controlled study

Background: The rate of cesarean delivery is on the rise in the USA. Satisfactory postoperative analgesia remains a top priority for cesarean delivery. Multimodal analgesia with a reduction in opioid consumption and improvement in patient satisfaction is a goal for anesthesiologists caring for this patient population. Our study sought to assess whether IV acetaminophen in four divided doses over 24 h decreased pain scores and opioid requirements in patients undergoing cesarean delivery with neuraxial anesthesia.Methods: 66 patients undergoing elective cesarean delivery under spinal anesthesia with hyperbaric bupivacaine 12 mg, fentanyl 10 µg, and preservative-free morphine 150 µg were randomized to receive either IV acetaminophen or IV placebo for four consecutive doses in the first 24 h postoperatively. The need for rescue medication using morphine equivalence, pain scores, patient satisfaction, and side effects were assessed by a blinded researcher in the first 24 and 48 h postoperatively.Results: There was no difference in opioid requirements in the acetaminophen versus placebo group, 44.32 ± 23 mg versus 47.59 ± 28 mg (p = .607), respectively at 24 h. There was also no difference at 48 h, 57.95 ± 20 mg versus 56.59 ± 22 mg (p = .795). Postoperative pain scores, patient satisfaction, and adverse events were similar in both groups as well.Conclusions: The results of this study failed to demonstrate any additional benefits of administering multiple doses of IV acetaminophen for treating postoperative pain in patients who have undergone CS surgery and receiving intra-thecal morphine as part of their anesthesia and analgesia.Trial Registry number: NCT02069184.

The effect of a scheduled regimen of acetaminophen and ibuprofen on opioid use following cesarean delivery

Objective The primary objective was to evaluate if the administration of ibuprofen and acetaminophen at regularly scheduled intervals impacts pain scores and total opioid consumption, when compared to administration based on patient demand. Methods A retrospective chart review was performed comparing scheduled vs. as-needed acetaminophen and ibuprofen regimens, with 100 women included in each arm. Demographics and delivery characteristics were collected in addition to pain scores and total ibuprofen, acetaminophen and oxycodone use at 24, 48 and 72 h postoperatively. Results The scheduled dosing group was found to have a statistically significant decrease in pain scores at all time intervals. Acetaminophen and ibuprofen usage were also noted to be higher in this group while narcotic use was reduced by 64%. Conclusion Scheduled dosing of non-narcotic pain medications can substantially decrease opioid usage after cesarean delivery and improve post-operative pain.

A prospective randomized trial of intravenous ketorolac vs. acetaminophen administered with opioid patient-controlled analgesia in gynecologic surgery

OBJECTIVE

To determine which non-narcotic analgesic, acetaminophen (Ofirmev®) or ketorolac (Toradol®), provides better post-operative pain control when combined with an opioid patient-controlled analgesia (PCA) pump. Secondary objectives include comparisons of the rates of ileus, post-operative bleeding, transfusions, and length-of-hospitalization (LOH).

METHODS

A prospective, randomized trial of acetaminophen (A) 1-g intravenous (IV) every 6-h or ketorolac (K) 15-mg IV every 6-h from post-operative day 1-3 in addition to an opioid PCA for patients undergoing benign or malignant gynecologic laparotomy procedures was performed. Abstracted data included pain levels via visual analogue pain scales (VAS), amount of narcotic used, hepatic enzyme levels, hemoglobin, urine output, blood transfusions, time to return of flatus and LOH.

RESULTS

One-hundred patients were accrued and underwent 55 benign gynecologic laparotomies and 45 cancer-related laparotomies. VAS pain levels (3.3 K, 3.5 A) and morphine PCA use (79.1 oral morphine equivalents [OME] K vs. 84.5 A) were not different, however dilaudid PCA usage was less by K patients (84.4 OME K and 136.8 OME A, p < 0.001). There was a significant hemoglobin change between the two groups (2.6 g K vs. 2 g A, p = 0.015), however blood transfusions were equal (28% K, 22% A, p > 0.05). Return of flatus was 2.7-days for K vs. 3.4-days for A (p = 0.011) and LOH was not different (4.4-days K vs. 5.1-days A, p = 0.094).

CONCLUSIONS

Both intravenous ketorolac and acetaminophen provide similar post-operative analgesia through VAS pain scales and total usage of morphine via PCA pumps. Use of ketorolac with dilaudid PCA was associated with less dependence on dilaudid and a quicker return of bowel function than acetaminophen, however length of stay and transfusion rates were not different.

Systemic adjunct analgesics for cesarean delivery: a narrative review

It is critical to adequately treat postoperative cesarean delivery pain. The use of parenteral or neuraxial opioids has been a mainstay, but opioids have side effects that can be troubling and the opioid crisis in the United States has highlighted the necessity to utilize analgesics other than opioids. Other analgesic options include neuraxial analgesics, nerve blocks such as the transversus abdominis plane block, and non-opioid parenteral and oral medications. The goal of this article is to review non-opioid systemic analgesic adjuncts following cesarean delivery, focusing on their efficacy and side effects as well as their impact on reduction of opioid requirements after surgery.

Protocol for a randomised, double-blind, placebo-controlled trial to explore the effect of tramadol in the prevention of postpartum depression (ETPPD)

INTRODUCTION

Postpartum depression is one of the most commonly experienced psychological disorders for women patients undergoing caesarean section, which accounts for about one-third of puerpera worldwide. Tramadol, a commonly used analgesic with an inhibitory effect on the reuptake of norepinephrine and serotonin, is an effective and well-tolerated agent for analgesia after caesarean section. Based on the role of changes in the postpartum levels of serotonin and norepinephrine in postpartum depression, we speculated that postoperative intravenous analgesia using tramadol may decrease the incidence of postpartum depression for caesarean patients. Therefore, this trial aimed to explore the effect of tramadol in the prevention of postpartum depression.

METHODS AND ANALYSIS

A randomised double-blind placebo-controlled trial will be performed and 1230 singleton parturients will be randomised to receive patient-controlled intravenous analgesia with tramadol or hydromorphone, or patient-controlled epidural analgesia with ropivacaine. The primary outcome of this trial will be the incidence of postpartum depression at 4 weeks after the caesarean section, together with the collection of the relevant data during hospitalisation and at 3 months after the caesarean section. Subgroup data according to the preoperative depression score will be analysed. Demographic characteristics, postoperative analgesic effects and postoperative recovery score will also be summarised and presented.

ETHICS AND DISSEMINATION

The current trial protocol was approved by the Institutional Ethics Committee of Xinqiao Hospital (ID: 2017-026), Third Military Medical University, Chongqing, China. The results of this trial will be disseminated at scientific meetings and in a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

NCT03309163; Pre-results.

Use of Intravenous Acetaminophen in Children for Analgesia After Spinal Fusion Surgery: A Randomized Clinical Trial

OBJECTIVES

Opioid pharmacotherapy is the cornerstone of postoperative analgesia. Despite its effectiveness, it has a variety of potential adverse effects. Therefore, a multimodal approach with non-opioid analgesics would be optimal. The aim of this study was to determine if intravenous (IV) acetaminophen would reduce opioid requirements and improve clinical outcomes in children after surgery.

METHODS

A single-center, randomized, double-blind study was conducted in 57 children (10-18 years old) undergoing posterior spine fusion surgery between July 2011 to May 2014. All subjects received either acetaminophen or placebo at the end of surgery, followed by repeated doses every 6 hours for a total of 8 doses.

RESULTS

In the first 24 postoperative hours, the average opioid consumption was lower for the active group compared with the placebo group (p = 0.02). The total unadjusted time to patient controlled analgesia (PCA) discontinuation was also longer in the placebo group than the active group (90 hours vs. 73 hours, p = 0.02); however, this was not statistically significant after normalizing for body weight. Additionally, time to first solid intake was longer without the use of acetaminophen (69 hours vs. 49 hours, p = 0.01).

CONCLUSIONS

Postoperative use of IV acetaminophen was associated with earlier time to diet advancement and discontinuation of IV analgesics and may result in lower opioid consumption.

The impact of intravenous acetaminophen on pain after abdominal surgery: a meta-analysis

BACKGROUND

Pain after surgery is commonly controlled with opioid pain medications. A multi-modal pain strategy that involves acetaminophen may help minimize the negative consequences of opioids, such as ileus, respiratory depression, and addictive potential. There are limited data on the effectiveness of intravenous (IV) acetaminophen in comparison with other nonopioid pain medications.

MATERIALS AND METHODS

Four databases were queried for the keywords "acetaminophen," "intravenous," and "postoperative". Prospective studies of adult patients receiving at least 24 h of IV acetaminophen after intraabdominal surgery were analyzed for 12- and 24-h pain scores and 24-h narcotic consumption. A random effects model was performed using mean differences and 95% confidence intervals to assess the effect of IV acetaminophen on outcomes. Heterogeneity was assessed using χ² and the I² statistics.

RESULTS

Seventeen articles were identified that complied with inclusion and exclusion criteria. There was no significant difference in 24-h pain scores between IV acetaminophen and any other comparator, or in secondary endpoints of 12-h pain scores and 24-h narcotic consumption. Subgroup analysis demonstrated significant benefit for IV acetaminophen in open surgeries for decreased 24-h narcotic consumption. When analyzing individual medications, non-steroidal anti-inflammatory drugs demonstrated the largest reduction in 24-h narcotic consumption. Data were of moderate quality and demonstrated significant heterogeneity between studies.

CONCLUSIONS

The lack of significant differences in primary endpoints may be explained by the heterogeneous, moderate-quality data. However, subgroup analyses suggested IV acetaminophen may be advantageous in open surgeries, and non-steroidal anti-inflammatory drugs may lower the 24-h narcotic requirement.

Intra-incisional liposomal bupivacaine and its impact on postcesarean analgesia: a retrospective study

PURPOSE

The efficacy of long-acting intraincisional bupivacaine in reducing postoperative opioid use among women who have undergone a cesarean is currently unknown.

MATERIALS AND METHODS

This was a retrospective case-control study with a 1:1 allocation. We identified 40 patients in each group, for a total of 80. The treatment group was administered 266 mg of liposomal bupivacaine after completion of the cesarean and was compared to historical controls. Data regarding anesthesia administered, opioid consumption, nonsteroidal anti-inflammatory use, acetaminophen use, type of cesarean, reason for cesarean, and length of postoperative stay were recorded.

RESULTS

The treatment group used 41.51 mg of morphine equivalents, while the control group consumed 69.90 mg (p < .001); multivariate analysis demonstrated a mean difference of 26.52 mg (95%CI 12.76-40.28). Univariate analysis demonstrated mean difference in intravenous (IV) ketorolac (40.77 mg, p < .001) and IV acetaminophen (1333.33 mg, p < .001) was different and greater in the treatment group; this was controlled for in the multivariate model. There was no difference in oral and IV ibuprofen or oral acetaminophen use between groups. There were no differences between the type of anesthesia, length of stay, reason for cesarean, and classical sections between groups.

CONCLUSIONS

Incisional administration of liposomal bupivacaine may be an effective adjunct in reducing opioid use postoperatively and may be a useful adjunct within an enhanced recovery program.

Perinatal and neonatal use of paracetamol for pain relief

Paracetamol (acetaminophen) is the most widely used drug to treat pain or fever in pregnant women or neonates, but its pharmacokinetics (PK) and pharmacodynamics (PD) warrant a focused analysis. During pregnancy, there is an important increase in paracetamol clearance. Consequently, it is reasonable to anticipate that the analgesic effect of paracetamol will decrease faster, whereas higher doses may result in even higher oxidative toxic metabolites. Therefore, most peripartal PD data relate to multimodal analgesia strategies. In neonates, weight/size is the most relevant covariate of paracetamol PK. This resulted in proposed dosing regimens containing higher doses than currently prescribed in the label for term neonates. Using adequate dosing, paracetamol is a poor procedural analgesic, is effective for mild-to-moderate pain, and has morphine-sparing effects. Short-term safety has been well documented, and there is active research investigating the potential association between paracetamol exposure and atopy, fertility, and neurobehavior.

Randomized controlled trial of intravenous acetaminophen for postcesarean delivery pain control

BACKGROUND

Cesarean delivery is a common surgery in the United States, with 1.3 million performed during 2009.¹ Obstetricians must balance the growing concern with opioid abuse, dependence, and side effects with optimal postoperative pain control. Intravenous acetaminophen may represent an additional method to decrease the reliance on opioid medications and improve postoperative pain following cesarean delivery.

OBJECTIVE

The objective of the study was to determine whether the administration of intravenous acetaminophen following routine scheduled cesarean delivery would decrease the need for narcotic medications to control postoperative pain.

STUDY DESIGN

This was an institutional review board-approved, double-blind, placebo-controlled, randomized trial, registered on clinicaltrials.gov (number 02046382). Women scheduled to undergo cesarean delivery with regional anesthesia at term were recruited. All perioperative and postpartum care was standardized via study order sets. Study patients were given all medications in a standardized manner receiving either acetaminophen 1000 mg intravenously or 100 mL saline (placebo) every 8 hours for 48 hours for a total of 6 doses. The pharmacy prepared intravenous acetaminophen and saline in identical administration bags labeled study drug to ensure blinding. The initial dose of study drug was given within 60 minutes of skin incision. Quantity of breakthrough and scheduled analgesic medications and self-reported pain levels on the Faces Pain Scale (0-10) before and after study drug administration were collected. Patient demographics were extracted from the chart. Power calculation determined that 45 patients per arm were required to detect a 30% reduction in postcesarean narcotic requirement with 80% power and a significance level of P = .05.

RESULTS

A total of 133 patients were consented for the study. Twenty-nine were excluded and 104 patients completed the study: 57 received intravenous acetaminophen and 47 received placebo. There were no differences in baseline demographic characteristics including patient age, body mass index, gravidity, parity, race, comorbidities, or number of prior cesarean deliveries. There were no differences between groups in estimated blood loss or length of stay. The total amount of oral narcotic medications consumed by patients receiving intravenous acetaminophen was significantly reduced when compared with the placebo group (47 mg vs 65 mg of oxycodone; P = .034). The total amount of ibuprofen used between groups was not different. There was no difference in pain scores between groups before and after study dose administration. There was no significant difference in narcotic side effects (nausea/emesis, respiratory depression, constipation) in either study arm.

CONCLUSION

Intravenous acetaminophen in the postoperative period following cesarean delivery resulted in a significant decrease in oral narcotic consumption for pain control.

Practice Bulletin No. 177: Obstetric Analgesia and Anesthesia

Labor causes severe pain for many women. There is no other circumstance in which it is considered acceptable for an individual to experience untreated severe pain that is amenable to safe intervention while the individual is under a physician's care. Many women desire pain management during labor and delivery, and there are many medical indications for analgesia and anesthesia during labor and delivery. In the absence of a medical contraindication, maternal request is a sufficient medical indication for pain relief during labor. A woman who requests epidural analgesia during labor should not be deprived of this service based on the status of her health insurance. Third-party payers that provide reimbursement for obstetric services should not deny reimbursement for labor analgesia because of an absence of "other medical indications." Anesthesia services should be available to provide labor analgesia and surgical anesthesia in all hospitals that offer maternal care (levels I-IV) (). Although the availability of different methods of labor analgesia will vary from hospital to hospital, the methods available within an institution should not be based on a patient's ability to pay.The American College of Obstetricians and Gynecologists believes that in order to allow the maximum number of patients to benefit from neuraxial analgesia, labor nurses should not be restricted from participating in the management of pain relief during labor. Under appropriate physician supervision, labor and delivery nursing personnel who have been educated properly and have demonstrated current competence should be able to participate in the management of epidural infusions.The purpose of this document is to review medical options for analgesia during labor and anesthesia for surgical procedures that are common at the time of delivery. Nonpharmacologic options such as massage, immersion in water during the first stage of labor, acupuncture, relaxation, and hypnotherapy are not covered in this document, though they may be useful as adjuncts or alternatives in many cases.

Efficacy of intravenous paracetamol on pressor response in patients undergoing cesarean section under general anesthesia

BACKGROUND AND AIMS

Profound hemodynamic alterations due to stress and pain during endotracheal intubation may cause deleterious effects. The purpose of this study was to evaluate the effect of intravenous (IV) paracetamol on hemodynamic changes due to endotracheal intubation during cesarean section under general anesthesia.

MATERIAL AND METHODS

Random allocation of one hundred and ten patients in two groups (Group A - placebo and Group B - paracetamol), was achieved as per computer generated table. The placebo (normal saline) and paracetamol solutions looked identical as both were available in 100 ml piggy bags and were labeled as study drug. Infusion of the drug was given 1 h before surgery. Two baseline readings of heart rate, systolic blood pressure (BP), diastolic BP and mean BP were recorded before induction, and these readings were repeated during intubation. Detrimental effect on neonate was evaluated by Apgar score measured at 1 and 5 min after birth.

RESULTS

There were no significant demographic differences found between the two groups. Hemodyamic changes during intubation also did not differ between the two groups.

CONCLUSION

Administration of IV paracetamol 1 h before cesarean section has no significant effect in preventing hemodynamic changes at the time of endotracheal intubation.

Comparison of paracetamol and fentanyl for pain relief during and after suction termination

Objectives:

To compare the combination of paracetamol (20 mg/kg) and propofol to fentanyl (1 µg/kg) and propofol in terms of providing adequate analgesia and a comparable recovery profile in suction termination procedures.

Methods:

This is a prospective, randomized clinical study in which we obtained informed consents from 146 women (fentanyl group: 76 [52.1%], paracetamol group: 70 [47.9%]) who were scheduled for suction curettage at the Istanbul Kanuni Sultan Suleyman Education and Training Hospital, Istanbul, Turkey in January 2015. Patients were randomly allocated into a fentanyl group or a paracetamol group. Visual analogue scores, modified Aldrete scores, and hemodynamic parameters were recorded during and after the surgical procedure. A record was also maintained of any adverse events.

Results:

When the modified Aldrete scores at 60 minutes, systolic pressures at 0 minutes, oxygen saturation at 10, 15, 20 minutes, diastolic blood pressure at 10, 15, 20 minutes, heart rates, and visual analogue scores were compared, there was no significant difference between groups (p>0.05). In the fentanyl group, systolic blood pressures at 5, 10, 15, 20 minutes and diastolic blood pressure at 5 minutes and oxygen saturation at 5 minutes were significantly lower (p<0.05).

Conclusion:

Our study demonstrates that the analgesic properties and recovery profiles of intravenous paracetamol is as effective as fentanyl when used in suction termination procedures. Further larger studies are still required.

Single-dose systemic acetaminophen to prevent postoperative pain: a meta-analysis of randomized controlled trials

OBJECTIVES

The effect of a single-dose systemic acetaminophen to treat postoperative pain has been previously quantified, but the effect of systemic acetaminophen to prevent postoperative pain is currently not well defined. The preventive analgesic effect of acetaminophen has yet to be quantified in a meta-analysis. The objective of the current investigation was to evaluate the effect of a single preventive dose of systemic acetaminophen on postoperative pain outcomes.

MATERIALS AND METHODS

A wide search was performed to identify randomized controlled trials that evaluated the effects of a single dose of systemic acetaminophen on pain outcomes in a large variety of surgical procedures. Meta-analysis was performed using a random-effect model.

RESULTS

Eleven randomized clinical trials evaluating 740 patients were included in the analysis. The weighted mean difference (95% confidence interval [CI]) of the combined effects favored acetaminophen over control for early pain at rest (≤4 h, -1.1 (-2.0 to -0.2)) and early pain at movement (24 h, -1.9 (-2.8 to -1.0)) Postoperative opioid consumption was decreased in the systemic acetaminophen group compared with control. Weighted mean difference (95% CI) of -9.7 (-13.0 to -6.4) mg morphine intravenous equivalents systemic acetaminophen also reduced postoperative nausea and vomiting compared with control, odds ratio (95% CI) of 0.25 (0.13 to 0.47), numbers needed to treat (95% CI)=3.3 (2.3 to 5.9).

DISCUSSION

Systemic acetaminophen, when used as a single-dose preventive regimen, is an effective intervention to reduce postoperative pain. It also reduces postoperative nausea and/or vomiting. Doses >1 g were not associated with greater reduction in pain outcomes.

Oral analgesia for relieving post-caesarean pain

BACKGROUND

Oral analgesia is a convenient and widely used form of pain relief following caesarean section. It includes various medications used at different doses alone or in adjunction to other form of analgesia.

OBJECTIVES

To determine the effectiveness, safety and cost-effectiveness of oral analgesia for post-caesarean pain relief.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 July 2014) and reference lists of retrieved studies.

SELECTION CRITERIA

Randomised controlled trials (RCTs). Cluster-randomised trials were eligible for inclusion but none were identified. Quasi-randomised and cross-over trials were not eligible for inclusion.Interventions included oral medication given to women for post-caesarean pain relief compared with oral medication, or placebo/no treatment.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed for inclusion all the potential studies and independently assessed trial quality, extracted the data using the agreed data extraction form, and checked them for accuracy.

MAIN RESULTS

Eight small trials involving 962 women (out of 13 included trials) contributed data to the analysis, of which only four trials had low risk of bias.None of the included studies reported on 'adequate pain relief', which is one of this review's primary outcomes. 1. Opiod analgesics versus placeboBased on one trial involving 120 women, the effect of opioids versus placebo was not significant in relation to the need for additional pain relief (primary outcome) (risk ratio (RR) 0.33, 95% confidence interval (CI) 0.06 to 1.92), and the effect in terms of adverse drug effects outcomes was also uncertain (RR 6.58, 95% CI 0.38 to 113.96).Low (75 mg) and high (150 mg) doses of tramadol had a similar effect on the need for additional pain relief (RR 0.67, 95% CI 0.12 to 3.78 and RR 0.14, 95% CI 0.01 to 2.68, respectively, one study, 80 women). 2. Non-opioid analgesia versus placeboThe confidence interval for the lower requirement for additional analgesia (primary outcome) with the non-opioid analgesia group was wide and includes little or no effect (average RR 0.70, 95% CI 0.48 to 1.01, six studies, 584 women). However, we observed substantial heterogeneity due to the variety of non-opioid drugs used (I(2) = 85%). In a subgroup analysis of different drugs, only gabapentin use resulted in less need for additional pain relief (RR 0.34, 95% CI 0.23 to 0.51, one trial, 126 women). There was no difference in need for additional pain relief with the use of celexocib, ibuprofen, ketoprofen, naproxen, paracetamol. Maternal drug effects were more common with the use of non-opioid analgesics (RR 11.12, 95% CI 2.13 to 58.22, two trials, 267 women).Gabapentin 300 mg (RR 0.25, 95% CI 0.13 to 0.49, one study, 63 women) and 600 mg (RR 0.44, 95% CI 0.27 to 0.71, one study, 63 women) as well as ketoprofen 100 mg (RR 0.55, 95% CI 0.39 to 0.79, one study 72 women) were both more effective than placebo with respect to the need for additional pain relief. However, the 50 mg ketoprofen group and the placebo group did not differ in terms of the number of women requiring additional pain relief (RR 0.82, 95% CI 0.64 to 1.07, one study, 72 women). 3. Combination analgesics versus placeboOur pooled analysis for the effect of combination analgesics on the need for additional pain relief was RR 0.70 (95% CI 0.35 to 1.40, three trials, 242 women, I(2) = 69%). When comparing different drugs within the combination oral analgesics versus placebo comparison we observed subgroup differences (P = 0.05; I² = 65.8%). One trial comparing paracetamol plus codeine versus placebo resulted in fewer women requiring additional pain relief (RR 0.44, 95% CI 0.23 to 0.82, one trial, 65 women). However, there were no differences in the the number of women requiring additional pain relief when comparing paracetamol plus oxycodone versus placebo, or paracetamol plus propoxyphene (RR 1.00, 95% CI 0.78 to 1.28, one trial, 96 women and RR 0.65, 95% CI 0.11 to 3.69, one trial, 81 women, respectively).Maternal drug effects were more common in combination analgesics group versus placebo (RR 13.18, 95% CI 2.86 to 60.68, three trials, 252 women). 4. Opioid analgesics versus non-opioid analgesicsThe confidence interval for the effect on additional pain relief between opioid and non-opioid drugs was very wide (RR 0.51, 95% CI 0.07 to 3.51, one trial, 121 women). Side effects were more common with the use opioids versus non-opioids analgesics (RR 2.32, 95% CI 1.15 to 4.69, two trials 241 women). 5. Opioid analgesics versus combination analgesicsThere was no difference in need for additional pain relief in opioid analgesics versus combination analgesics based on one study involving 121 women comparing tramadol and paracetamol plus propoxyphene (RR 0.51, 95% CI 0.07 to 3.51). Maternal adverse effects also did not differ between the two groups (RR 6.74, 95% CI 0.39 to 116.79). 6. Non-opioid versus combination analgesicsThe need for additional pain relief was greater in the group of women who received non-opoid analgesics (RR 0.87, 95% CI 0.81 to 0.93, one trial, 192 women) compared with the group of women who received combination analgesics. Secondary outcomes not reported in the included studiesNo data were found on the following secondary outcomes: number of days in hospital post-operatively, re-hospitalisation due to incisional pain, fully breastfeeding on discharge, mixed feeding at discharge, incisional pain at six weeks after caesarean section, maternal post partum depression, effect (negative) on mother and baby interaction and cost of treatment.

AUTHORS' CONCLUSIONS

Eight trials with 962 women were included in the analysis, but only four trials were of high quality. All the trials were small. We carried out subgroup analysis for different drugs within the same group and for high versus low doses of the same drug. However, the relatively few studies (one to two trials) and numbers of women (40 to 136) limits the reliability of these subgroup analyses.Due to limited data available no conclusions can be made regarding the safest and the most effective form of oral analgesia for post-caesarean pain. Further studies are necessary.

Comparison between intravenous paracetamol and fentanyl for intraoperative and postoperative pain relief in dilatation and evacuation: Prospective, randomized interventional trial

Background and Aims:

Dilatation and Evacuation procedure involves pain, for which pain control measures need to be undertaken. The purpose of this study was to compare paracetamol with fentanyl for pain relief in dilatation and curettage procedures.

Materials and Methods:

Sixty female patients were randomly included during the period from March 1, 2012 to February 28, 2013. All patients had received oral midazolam 7.5 mg as a premedication 30 min before procedure in the ward. Group P had received intravenous (IV) paracetamol 15 mg/kg in the waiting area of the operating room 15 min before starting the procedure. Group F had received IV fentanyl 2 ug/kg/min at induction of anesthesia. Pain scores on a numerical rating scale at 5, 15, and 30 min intervals after surgery were recorded.

Results:

Mild pain was commonly observed in both groups, an insignificant difference between groups.

Conclusion:

The study demonstrates the usefulness of IV paracetamol which may be as effective as fentanyl in dilation and curettage procedures.

Impact of Postoperative Intravenous Acetaminophen on Opioid Requirements and Pain Scores Following Gynecologic Procedures

OBJECTIVE

This study aims to assess the impact of postoperative intravenous (IV) acetaminophen on opioid requirements and pain scores in patients following gynecologic procedures.

STUDY DESIGN

A retrospective cohort study of patients undergoing gynecologic procedures was conducted to assess the impact of adding scheduled IV acetaminophen to postoperative analgesic regimens. The control group consisted of patients admitted prior to formulary addition of IV acetaminophen; the study group consisted of patients admitted after formulary addition of IV acetaminophen who received scheduled IV acetaminophen for at least the first 24 hours postoperatively. Opioid requirements 0 to 24 hours postoperatively served as the primary end point. Secondary end points included average pain score, cumulative acetaminophen dose, nonopioid analgesic requirements, and rate of adverse events 0 to 24 hours postoperatively.

RESULTS

One hundred and thirty-seven patients who underwent a gynecologic procedure from January 2009 to April 2013 were included in this study. Baseline characteristics were similar between the groups. In the first 24 hours postoperatively, there was no difference in opioid requirements between the groups (21 mg [interquartile range, IQR, 15-39.8 mg] vs 32.6 mg [IQR, 16.75-41 mg], P = 0.150). The average pain score and incidence of adverse events did not differ between the 2 groups.

CONCLUSION

Postoperative administration of IV acetaminophen did not provide a significant opioid-sparing effect in patients undergoing gynecologic procedures.

Intravenous paracetamol versus intramuscular pethidine in relief of labour pain in primigravid women

BACKGROUND

Intramuscular pethidine is one of most common opioids used for labour analgesia. There are a number of concerns in the literature regarding the use of pethidine. The aim of this study is to compare analgesic efficacy of paracetamol with pethidine for labour pain in normal vaginal delivery.

MATERIALS AND METHODS

In this single-blinded, randomised control trial, 80 primigravid singleton women with full-term pregnancy candidate for normal vaginal delivery, were entered the trial and divided in to pethidine (A) and paracetamol (B) groups. At the time of admission, age and body mass index of mother and gestational age based on last day of period were recorded. In both groups, intravenous promethazine and hyoscine were administered to each patient at the first stage of delivery. From beginning of active phase of delivery, patients in group A received 50 mg intramuscular pethidine injection. At the same time patients in group B, received an intravenous solution infusion containing 1000 mg paracetamol and 300 cc of normal saline. After child birth, average labour pain was assessed using Visual Analogue Scale (VAS) by direct questioning from patient in both groups.

RESULTS

After patients' selection, 19 individual omitted during study due to exclusion criteria and finally 30 patients in paracetamol group and 31 patients in pethidine group remained to enter the trial. There was no significant difference in age and BMI of mothers between both groups (P > 0.05). Maternal age and labour duration in paracetamol group had no meaningful difference with maternal age and labour duration of patients in pethidine group (P > 0.05). The average VAS pain score was significantly lower in paracetamol comparing to that of pethidine group (8.366 out of 10, 9.612 out of 10, respectively, P < 0.001).

CONCLUSION

It is concluded that intravenous paracetamol is more effective than intramuscular pethidine to relief labour pain in normal vaginal delivery.

Attenuation of Hemodynamic Responses to Laryngoscopy and Tracheal Intubation: Propacetamol versus Lidocaine-A Randomized Clinical Trial

The purpose of this study is to assess the effects of propacetamol on attenuating hemodynamic responses subsequent laryngoscopy and tracheal intubation compared to lidocaine. In this randomized clinical trial, 62 patients with the American Anesthesiologists Society (ASA) class I/II who required laryngoscopy and tracheal intubation for elective surgery were assigned to receive propacetamol 2 g/I.V./infusion (group P) or lidocaine 1.5 mg/kg (group L) prior to laryngoscopy. Systolic and diastolic blood pressures (SBP, DBP), mean arterial pressure (MAP), and heart rate (HR) were recorded at baseline, before laryngoscopy and within nine minutes after intubation. In both groups P and L, MAP increased after laryngoscopy and the changes were statistically significant (P < 0.001). There were significant changes of HR in both groups after intubation (P < 0.02), but the trend of changes was different between two groups (P < 0.001). In group L, HR increased after intubation and its change was statistically significant within 9 minutes after intubation (P < 0.001), while in group P, HR remained stable after intubation (P = 0.8). Propacetamol 2 gr one hour prior intubation attenuates heart rate responses after laryngoscopy but is not effective to prevent acute alterations in blood pressure after intubation.

A randomised controlled trial of parecoxib, celecoxib and paracetamol as adjuncts to patient-controlled epidural analgesia after caesarean delivery

The benefit of combining non-opioid analgesics with neuraxial opioids for analgesia after caesarean delivery has not been clearly established. Larger doses of paracetamol or cyclooxygenase-2 inhibitors have not been evaluated. A randomised, double blind, double-dummy, parallel group placebo-controlled clinical trial was conducted among women having elective caesarean delivery under spinal anaesthesia, followed by pethidine patient-controlled epidural analgesia. Patients received placebos (group C); intravenous parecoxib 40 mg then oral celecoxib 400 mg at 12 hours (group PC); intravenous paracetamol 2 g then oral 1 g six-hourly (group PA); or these regimens combined (group PCPA). The primary outcome was 24-hour postoperative patient-controlled epidural pethidine use and the main secondary outcome was postoperative pain. One hundred and thirty-eight women were recruited but 27 subsequently met exclusion criteria, leaving 111 who were randomised, allocated and analysed by intention-to-treat (n=23, 30, 32 and 26 in groups C, PC, PA and PCPA respectively). There were no differences between groups for pethidine consumption, based on either intention-to-treat (median 365, 365, 405 and 360 mg in groups C, PC, PA and PCPA respectively, P=0.84) or per protocol analysis (17 major violations). Dynamic pain scores did not differ between groups but requirement for, and dose of, supplementary oral tramadol was least in group PCPA (incidence 23% versus 48%, 70% and 58% in groups C, PC and PA respectively, P=0.004). The addition of regular paracetamol, cyclooxygenase-2 inhibitors or both to pethidine patient-controlled epidural post-caesarean analgesia did not provide a pethidine dose-sparing effect during the first 24 hours.

Intravenous acetaminophen: a review of pharmacoeconomic science for perioperative use

Hospitals are subject to more economic pressures than ever before. On the one hand, cost containment or cost reduction is paramount, particularly in relation to costly branded pharmaceuticals. On the other hand, quality measures and value-based reimbursement penalizes poor patient care. Multimodal analgesia sits squarely in this quandary, since its very nature requires use of multiple drugs with their associated costs, though this approach has the potential to improve quality of care. We undertook a comprehensive review of the pharmacoeconomics of IV acetaminophen, a new drug useful as part of a multimodal analgesic approach. While this new branded drug adds to direct drug costs, there is clear potential for IV acetaminophen to reduce the incidence of opioid-related adverse events and, in so doing, result in net hospital savings. This review describes many clinical studies showing significant improvements in postoperative nausea and vomiting, excessive sedation and pruritus. In addition, we describe studies demonstrating faster recovery times in the post-anesthesia care unit, intensive care unit and total hospital length of stay. Lastly, we summarize many studies demonstrating the robust effect of IV acetaminophen on patient satisfaction. A holistic view of total hospital performance should be adopted when reviewing drugs rather than a silo mentality within the pharmacy. While IV acetaminophen adds to drug costs, the body of evidence indicates this drug has the potential to improve outcomes and hospital efficiency.

Nonsteroidal anti-inflammatory drugs during pregnancy and the initiation of lactation

Nonsteroidal anti-inflammatory drugs (NSAIDs) and aspirin, which are available as "over-the counter" medications in most countries, are widely used by both pregnant and lactating women. They are popular non-opioid analgesics for the treatment of pain after vaginal and operative delivery. In addition, NSAIDs are used for tocolysis in premature labor, and low-dose aspirin has a role in the prevention of preeclampsia and recurrent miscarriage in antiphospholipid syndrome. NSAIDs and aspirin may affect fertility and increase the risk of early pregnancy loss. In the second trimester their use is considered reasonably safe, but has been associated with fetal cryptorchism. In the third trimester, NSAIDs and aspirin are usually avoided because of significant fetal risks such as renal injury, oligohydramnios, constriction of the ductus arteriosus (with potential for persistent pulmonary hypertension in the newborn), necrotizing enterocolitis, and intracranial hemorrhage. Maternal administration or ingestion of most NSAIDs results in low infant exposure via breastmilk, such that both cyclooxygenase-1 and cyclooxygenase-2 inhibitors are generally considered safe, and preferable to aspirin, when breastfeeding.

Perioperative use of etoricoxib reduces pain and opioid side-effects after total abdominal hysterectomy: a double-blind, randomized, placebo-controlled phase III study

OBJECTIVE

To evaluate the effects of two different doses of etoricoxib delivered perioperatively compared with placebo and standard pain management on pain at rest, pain with mobilization, and use of additional morphine/opioids postoperatively.

RESEARCH DESIGN AND METHODS

In this double-blind, placebo-controlled, randomized clinical trial, we evaluated postoperative pain following total abdominal hysterectomy over 5 days in patients receiving placebo or etoricoxib administered 90 min prior to surgery and continuing postoperatively. Patients were randomly assigned to receive either placebo (n = 144), etoricoxib 90 mg/day (n = 142), or etoricoxib 120 mg/day (n = 144). Average Pain Intensity at Rest over days 1-3 (0- to 10-point numerical rating scale [NRS]) was the primary efficacy endpoint. Secondary endpoints included Average Pain Intensity upon Sitting, Standing, and Walking over days 1-3 (0- to 10-point NRS) as well as Average Total Daily Dose of Morphine over days 1-3.

CLINICAL TRIAL REGISTRATION

This trial is registered on www.clinicaltrials.gov (NCT00788710).

RESULTS

The least squares (LS) means (95% CI) for the primary endpoint were 3.26 (2.96, 3.55); 2.46 (2.16, 2.76); and 2.40 (2.11, 2.69) for placebo, etoricoxib 90 mg, and etoricoxib 120 mg, respectively, significantly different for both etoricoxib doses versus placebo (p < 0.001). Patients on etoricoxib 90 mg and 120 mg required ~30% less morphine per day than those on placebo (p < 0.001), which led to more rapid bowel recovery in the active treatment groups by ~10 hours vs. placebo. A greater proportion of patients on etoricoxib (10-30% greater than placebo) achieved mild levels of pain with movement, defined as pain ≤3/10.

LIMITATIONS

A key limitation for this study was that movement-evoked pain measurements were not designated as primary endpoints.

CONCLUSION

In patients undergoing total abdominal hysterectomy, etoricoxib 90 mg and 120 mg dosed preoperatively and then continued postoperatively significantly reduces both resting and movement-related pain, as well as reduced opioid (morphine) consumption that led to more rapid bowel recovery.

Clinical and economic evidence for intravenous acetaminophen

Intravenous acetaminophen received United States Food and Drug Administration approval in November 2010 for the management of mild-to-moderate pain, management of moderate-to-severe pain with adjunctive opioid analgesics, and reduction of fever. Although intravenous acetaminophen generally improved pain relief and demonstrated opioid-sparing effects compared with placebo, it did not consistently reduce the frequency of opioid-related adverse events (e.g., postoperative nausea and vomiting). The safety and efficacy of intravenous acetaminophen as an antipyretic agent have been documented in adults and children; however, its cost is several-fold higher than that of the oral and rectal formulations. Although use of intravenous acetaminophen has reduced other postoperative resource utilization (e.g., hospital length of stay) in some studies outside the United States in patients undergoing abdominal surgery, a full economic evaluation in the United States has yet to be undertaken. In addition, its administration time (15-min infusion) and packaging (glass, single-use vial) have the potential to adversely affect patient flow in the postanesthesia care unit, create burden on patient care units, and lead to drug waste. Furthermore, 1 g of intravenous acetaminophen is formulated in 100 ml of solution, which may be an issue for patients with fluid restrictions. Given the clinical and economic evidence currently available, intravenous acetaminophen should not replace oral or rectal acetaminophen, but its use may be considered in a limited number of patients who cannot receive drugs orally and rectally and who cannot tolerate other parenteral nonopioid analgesic or antipyretic agents.

Acetaminophen injection: a review of clinical information

Acetaminophen injection is an antipyretic and analgesic agent recently marketed in the United States as Ofirmev. Five published trials directly compare acetaminophen injection to drugs available in the United States. For management of pain in adults, acetaminophen injection was at least as effective as morphine injection in renal colic, oral ibuprofen after cesarean delivery, and oral acetaminophen after coronary artery bypass surgery. In children (3 to 16 years old), single-dose acetaminophen injection was similar to meperidine intramuscular (i.m.) for pain after tonsillectomy; readiness for discharge from the recovery room was shorter with acetaminophen injection (median 15 minutes) compared with meperidine i.m. (median 25 minutes), P = .005. In children (2 to 5 years old) postoperative adenotonsillectomy or adenoidectomy, the time to rescue analgesia was superior with high-dose acetaminophen rectal suppository (median 10 hours) compared with acetaminophen injection (median 7 hours), P = .01. One published trial demonstrated acetaminophen injection is noninferior to propacetamol injection for fever related to infection in pediatric patients. Dosing adjustments are not required when switching between oral and injectable acetaminophen formulations in adult and adolescent patients. Acetaminophen injection represents another agent for multimodal pain management.

Use of intravenous acetaminophen in the treatment of postoperative pain

Pain management is a crucial component in the care of the postoperative patient. Although there have been innovative advances in pain management and new analgesic modalities, a need still exists for safer and more tolerable analgesics for the management of pain in the postoperative setting. An intravenous formulation of acetaminophen has been available in Europe for more than 20 years and may soon be reaching the US market. Intravenous acetaminophen may help reduce the consumption of opioid analgesics and has a safety and tolerability profile comparable to placebo. This review will discuss the novel characteristics of intravenous acetaminophen that may make it an attractive choice for the management of acute pain in the postoperative period.

Acetaminophen Intravenous

Each month, subscribers to The Formulary Monograph Service receive 5 to 6 well-documented monographs on drugs that are newly released or are in late phase 3 trials. The monographs are targeted to Pharmacy & Therapeutics Committees. Subscribers also receive monthly 1-page summary monographs on agents that are useful for agendas and pharmacy/nursing in-services. A comprehensive target drug utilization evaluation/medication use evaluation (DUE/MUE) is also provided each month. With a subscription, the monographs are sent in print and are also available on-line. Monographs can be customized to meet the needs of a facility. Subscribers to The Formulary Monograph Service also receive access to a pharmacy bulletin board, The Formulary Information Exchange (The F.I.X.). All topics pertinent to clinical and hospital pharmacy are discussed on The F.I.X. Through the cooperation of The Formulary, Hospital Pharmacy publishes selected reviews in this column. For more information about The Formulary Monograph Service or The F.I.X., call The Formulary at 800-322-4349. The April 2011 monograph topics are on vilazodone hydrochloride, hydroxyprogesterone caproate, gabapentin extended-release, spinosad 0.9% topical suspension, and aclidinium bromide. The DUE/MUE is on pegloticase.

Intravenous acetaminophen

Acetaminophen has unique analgesic and antipyretic properties. It is globally recommended as a first-line agent for the treatment of fever and pain due to its few contraindications. Acetaminophen lacks the significant gastrointestinal and cardiovascular side effects associated with nonsteroidal anti-inflammatory drugs and narcotics. An intravenous formulation of acetaminophen is available in Europe and is currently undergoing extensive clinical development for use in the United States. This use may have important implications for management of postoperative pain and fever. This review summarizes recent clinical trial experiences with intravenous acetaminophen for the treatment of postoperative pain and fever in adult and pediatric subjects.

[Postoperative multimodal pain management : Cost-minimisation analysis from a hospital's point of view]

BACKGROUND

Adequate pain management after major surgery is important to improve patients' quality of life and to support the healing process. Since the cost for pain management is included in the DRG system for hospital reimbursement, hospitals should aim to provide adequate postoperative pain management at the lowest possible cost. In this study we compare two multimodal pain management schemes for postoperative pain management in a cost-minimisation analysis.

METHODS

In a decision analytic model two treatment regimes for postoperative pain management are compared in a cost-minimisation analysis: diclofenac + morphine vs paracetamol vs morphine. The study is performed from the perspective of a public hospital. Due to the short time horizon costs are not discounted.

RESULTS

Assuming comparable effectiveness for adequate postoperative pain management, the expected value in the decision tree model for the combination diclofenac + morphine is 13.37 EUR and for the combination paracetamol + morphine 32.23 EUR, respectively. The results are robust under various one- and two-way sensitivity analyses.

CONCLUSION

With no contraindications given the combination diclofenac + morphine is more cost-effective for postoperative pain management after major surgery compared to paracetamol + morphine.

Analgesia after caesarean delivery

As the number of women giving birth by caesarean increases throughout most of the developed world, so too is research into postoperative pain relief for these women. Like most other post-surgical populations, the new mother needs effective pain relief so that she can mobilise early but she also has the added responsibility of needing to care for her newborn baby. There is no 'gold standard' for post-caesarean pain management; the number of options is large and the choice of method is at least partly determined by drug availability, regional and individual preferences, resource limitations and financial considerations. Most methods rely on opioids, supplemented with anti-inflammatory analgesics, nerve blocks or other adjunctive techniques. The aim of this review is to detail commonly used opioid-based methods and to review the evidence supporting non-opioid methods, when incorporated into a multimodal approach to post-caesarean pain management. Areas of promising research are also discussed.

Intravenous paracetamol (acetaminophen)

Intravenous paracetamol (rINN)/intravenous acetaminophen (USAN) is an analgesic and antipyretic agent, recommended worldwide as a first-line agent for the treatment of pain and fever in adults and children. In double-blind clinical trials, single or multiple doses of intravenous paracetamol 1 g generally provided significantly better analgesic efficacy than placebo treatment (as determined by primary efficacy endpoints) in adult patients who had undergone dental, orthopaedic or gynaecological surgery. Furthermore, where evaluated, intravenous paracetamol 1 g generally showed similar analgesic efficacy to a bioequivalent dose of propacetamol, and a reduced need for opioid rescue medication. In paediatric surgical patients, recommended doses of intravenous paracetamol 15 mg/kg were not significantly different from propacetamol 30 mg/kg for the treatment of pain, and showed equivocal analgesic efficacy compared with intramuscular pethidine 1 mg/kg in several randomized, active comparator-controlled studies. In a randomized, noninferiority study in paediatric patients with an infection-induced fever, intravenous paracetamol 15 mg/kg treatment was shown to be no less effective than propacetamol 30 mg/kg in terms of antipyretic efficacy. Intravenous paracetamol was well tolerated in clinical trials, having a tolerability profile similar to placebo. Additionally, adverse reactions emerging from the use of the intravenous formulation of paracetamol are extremely rare (<1/10 000). [table: see text].

Recent advances in the pharmacological management of pain

Pain is an unpleasant sensation that originates from ongoing or impending tissue damage. Management of different types of pain (acute, postoperative, inflammatory, neuropathic or cancer) is the most frequent issue encountered by clinicians and pharmacological therapy is the first line of approach for the treatment of pain. This review presents and discusses recent clinical advances regarding both the improvements in delivery of analgesic drugs and improvements in the design of analgesic molecules. The new modalities of administration of analgesics used in the clinic are reviewed, including skin patches, oral and mucosal sprays, transdermal delivery systems and intranasal administration. New insights are then presented on standard drugs used to relieve pain, such as opioids (including tramadol), NSAIDs including selective cyclo-oxygenase-2 inhibitors, paracetamol (acetaminophen), local anaesthetics and adjuvant analgesics such as antidepressants, anticonvulsants (gabapentin and pregabalin), cannabinoids, ketamine and others (e.g. nefopam). Although the understanding of pain mechanisms has improved significantly recently, much more is yet to be discovered and awaited. Broadening of our knowledge is needed to improve basic and clinical research in this field in order to better alleviate pain in millions of people.