By: Rose Fontana BSN, RRNA and Courtney Henderson BSN, RRNA

Webster University Committee Members: o Michael Burns MS, CRNA o Christopher Black MS, CRNA o Jill Stulce PhD(c), CRNA Phelps County Regional Medical Center

Most common surgical procedure performed in U.S. o 2012: 1,296,531 Major abdominal surgery High postoperative pain Pain delays ambulation, mother- infant bonding, and decreases patient satisfaction

 Opioids: first line of treatment  Many adverse effects  Harmful to mom and possibly to baby  Delays bonding and ambulation  A multimodal analgesic regimen decreases the need for rescue opioids

First synthesized in 1878 by Morse First used in clinical practice in 1887 by Von Mering N-acetyl-p-aminophenol Non-salicylate antipyretic Non-opioid analgesic

● Mechanisms of Action- not fully understood ○ Inhibits prostaglandin synthesis ○ Serotonergic pathway activation ○ Cannabinoid receptor stimulation ○ N-methyl-D-aspartate receptor inhibition

Even after spinal anesthesia and TAP blocks, patients continue to experience breakthrough pain in the early post cesarean delivery period. A multimodal analgesic regimen can decrease the amount of rescue opioid medications necessary for adequate pain control with less unwanted opioid side effects.

The purpose of this study was to determine if the administration of intravenous acetaminophen following cesarean delivery leads to a decrease in postoperative opioid requirements

Null Hypothesis: The use of intravenous acetaminophen in combination with a multimodal pain management regimen will not decrease postoperative opioid requirements after cesarean delivery Alternative Hypothesis: The use of intravenous acetaminophen in combination with a multimodal pain management regimen will decrease postoperative opioid requirements after cesarean delivery

Each cesarean delivery patient will receive: o Subarachnoid block with 0.75% bupivacaine in 8.25% dextrose o Intrathecal morphine 0.1mg o Intrathecal fentanyl mcg o TAP block with mL 0.5% ropivacaine o Ketorolac 30 mg every 6 hours for the first 24 hours postoperatively

Does intravenous acetaminophen decrease postoperative opioid requirements following cesarean delivery?

Retrospective analysis of 329 patient charts o 145 cases during January 1, 2012-November 2012  Control Group= No Acetaminophen o 182 cases during November December 31, 2013  Experimental Group= 1 gram of IV Acetaminophen every six hours for 24 hours The opioid medication consumption for each patient was totaled and converted to IV morphine equivalents using an opioid analgesic converter from GlobalRPH

Patients included in this study: o Females undergoing elective cesarean delivery o Each received entire pain management protocol :  Subarachnoid block with 0.75% bupivacaine in 8.25% dextrose  Intrathecal morphine 0.1mg  Intrathecal fentanyl mcg  TAP block with mL 0.5% ropivacaine  Ketorolac 30 mg every 6 hours for the first 24 hours postoperatively o Acetaminophen group also received 1 g of IV acetaminophen every 6 hours for the first 24 hours postoperatively

Exclusion criteria for this study included: o Failure to receive the entire pain management protocol o General anesthetic o ICU admission or another surgery within 24 hours o Contraindication to regional anesthesia o Additional gynecological surgeries o Emergency cesarean delivery

145 charts were reviewed o 40 charts were excluded due to an incomplete pain management protocol o 27 charts were excluded due to additional gynecological procedures o 13 charts were excluded due to conversion to general anesthesia, intensive care unit admission or additional surgery within 24 hours of cesarean delivery, or a multitude of factors Total of 65 patients in the non-acetaminophen group

184 charts were reviewed o 55 charts were excluded due to an incomplete pain management protocol o 26 charts were excluded due to additional gynecological procedures o 21 charts were excluded due to conversion to general anesthesia, intensive care unit admission or additional surgery within 24 hours of CD, or a multitude of factors Total of 82 patients in the acetaminophen group

Data was recorded in Microsoft Excel and converted for analysis using GraphPad Prism 5.0 A significance level of p<0.05 was used in all analyses

NON-ACETAMINOPHEN (n=65) ACETAMINOPHEN* (n=82) Mean ± Std. Deviation AGE27.57 ± ± BMI34.13 ± ± PREVIOUS CD ± ± ASA 1/2/32/60/34/74/4 *Experimental group received 4g IV acetaminophen in the first 24 hours postoperatively in addition to the pain management protocol

Age: No significant difference (p=0.2237) BMI: No significant difference (p=0.8600) Previous Cesarean Delivery: No significant difference (p=0.7319) ASA I/II/III Non-Acetaminophen Group- 2/60/3 Acetaminophen Group- 4/74/4

Assumptions relative to this study include o All anesthetic procedures were performed and documented correctly o Opioid medications and intravenous acetaminophen were administered and documented accurately

Non-Acetaminophen: 3.33 mg of morphine Acetaminophen: 3.07 mg of morphine

Mean Morphine Consumption: o One-tailed t-test showed:  No significant decrease (p=0.3456)

No statistically significant decrease in postoperative morphine consumption with the addition of IV acetaminophen to a multimodal pain management regimen following cesarean delivery The results are not conclusive for a benefit of the addition of the IV acetaminophen We accept the null hypothesis

Multimodal pain management protocol without acetaminophen mean opioid consumption was 3.33mg A study by Girgin, Gurbet, Turker, Aksu, and Gulhan Intrathecal morphine mg + 0.5% bupivacaine mean opioid consumption was 23.5mg Supports use of this multimodal pain management protocol

A total of 28 patients from both the non-acetaminophen and acetaminophen groups were excluded for no ketorolac administration These patients’ morphine consumption was calculated and found to be greater than those that received the entire pain management protocol

n=147 all those included in the study o mean opioid consumption: mg n=28 no ketorolac o mean opioid consumption: mg A Welch’s correction was applied to a t-test to analyze significance o There was a significance found with p= Although corrections were made for the variance in sample size, it makes the significance of the p value unreliable cannot be considered dependable results warrants further study

of the 28 that did not receive ketorolac o n=11 non-acetaminophen group  mean morphine consumption was: mg o n=17 acetaminophen group  mean morphine consumption was: mg o p= No significance that intravenous acetaminophen lowers postoperative opioid requirements in the absence of ketorolac

Perform a prospective randomized double-blind study evaluating the effect of ketorolac as part of a multimodal analgesic regimen post cesarean delivery o Incidental findings of this study suggest investigation of ketorolac efficacy would be advantageous

Limitations for this study include o Only measured opioid consumption for 24 hours o Did not evaluate  pain scores  time to first ambulation  sedation scores  patient satisfaction o Retrospective: no influence on multimodal pain management regimen, already in place  dependent on staff to give appropriate postoperative doses o Intrathecal morphine shortage

Perform this study as a prospective randomized double-blind study with better controlled variables o Same surgeon and anesthesia provider placing the spinal and TAP block o The same postoperative opioid medications o Identical anesthetic and analgesic dosages

Martin, J., Hamilton, B., Ventura S., Osterman M., Curtin, S., & Mathews, T. J., (2013). Births: Final data for National Vital Statistics Reports; National Center for Health Statistics, 62(9), ● Mehta, V., & Shah, S. (2010). Paracetamol: the forgotten drug. British Journal Of Hospital Medicine (London, England: 2005), 71(11), ● Girgin, N., Gurbet, A., Turker, G., Aksu, H., & Gulhan, N. (2008). Intrathecal morphine in anesthesia for cesarean delivery: dose-response relationship for combinations of low-dose intrathecal morphine and spinal bupivacaine. Journal of Clinical Anesthesia, 20(3),