Analgesia / Pain

#### ANALGESIA / PAIN MANAGEMENT

J Infus Nurs. 2018 Sep/Oct;41(5):284-292

# Ketamine infusions for outpatients pain management: a policy development project.

Allen C, Conner R, Ivester JR Jr.

Current literature supports using ketamine for both acute and chronic pain management. It is imperative that the development of evidence-based protocols and policies keep pace with health care delivery to ensure patient safety. This project's objective was to formulate an outpatient ketamine infusion policy that promotes consistent and evidence-based care within a specified hospital system. This policy addresses potential side effects and minimization of adverse events by addressing patient selection, level of nursing care required, appropriate monitoring, and staff education.

Clin Pract Cases Emerg Med. 2017 Oct 3;1(4):323-325

# The case of ketamine allergy.

Bylund W, Delahanty L, Cooper M

Ketamine is often used for pediatric procedural sedation due to low rates of complications, with allergic reactions being rare. Immediately following intramuscular (IM) ketamine administration, a three-year-old female rapidly developed facial edema and diffuse urticarial rash, with associated wheezing and oxygen desaturation. Symptoms resolved following treatment with epinephrine, dexamethasone and diphenhydramine. This case presents a clinical reaction to ketamine consistent with anaphylaxis due to histamine release, but it is uncertain whether this was immunoglobulin E mediated. This is the only case reported to date of allergic reaction to IM ketamine, without co-administration of other agents.

Ann Emerg Med. 2018 Aug;72(2):133-134

# Is low-dose ketamine an effective alternative to opioids for the treatment of acute pain in the emergency department?

Gottlieb M, Ryan K, Binkley C

According to limited evidence, low-dose ketamine and morphine appear to provide similar levels of pain relief at 30 minutes; however, low-dose ketamine is associated with a higher rate of self-limited neuropsychological adverse events.

Ann Emerg Med. 2018 Aug;72(2):115-119

# The newest threat to emergency department procedural sedation.

Green S, Roback M, Krauss B

Guidelines for procedural sedation first appeared in 1985—a National Institutes of Health guideline for dentists1and an American Academy of Pediatrics guideline for children. Because procedural sedation is a multidisciplinary field, a wide array of specialty societies, including the American College of Emergency Physicians (ACEP), subsequently crafted and periodically update their own sedation guidelines. These documents are not mandated by regulatory bodies such as The Joint Commission or the Centers for Medicare & Medicaid Services (CMS), but are instead initiated by the specialty societies on behalf of their members. These guidelines begin with accepted core sedation principles and include customized elements to address specialty-specific needs, challenges, and patient populations.

Am J Emerg Med. 2018 May 16. pii: S0735-6757(18)30407-8. doi: 10.1016/j.ajem.2018.05.030. [Epub ahead of print]

# Intravenous subdissociative-dose ketamine versus morphine for acute geriatric pain in the Emergency Department: A randomized controlled trial.

Motov S, Mann S, Drapkin J, Butt M, Likourezos A, Yetter E, Brady J, Rothberger N, Gohel A, Flom P, Mai M, Fromm C, Marshall J

STUDY OBJECTIVE: We compare the analgesic efficacy and safety of subdissociative intravenous-dose ketamine (SDK) versus morphine in geriatric Emergency Department (ED) patients.

METHODS: This was a prospective, randomized, double-blind trial evaluating ED patients aged 65 and older experiencing moderate to severe acute abdominal, flank, musculoskeletal, or malignant pain. Patients were randomized to receive SDK at 0.3 mg/kg or morphine at 0.1 mg/kg by short intravenous infusion over 15 min. Evaluations occurred at 15, 30, 60, 90, and 120 min. Primary outcome was reduction in pain at 30 min. Secondary outcomes included overall rates of adverse effects and incidence of rescue analgesia.

RESULTS: Thirty patients per group were enrolled in the study. The primary change in mean pain scores was not significantly different in the ketamine and morphine groups: 9.0 versus 8.4 at baseline (mean difference 0.6; 95% CI -0.30 to 1.43) and 4.2 versus 4.4 at 30 min (mean difference -0.2; 95% CI -1.93 to1.46). Patients in the SDK group reported higher rates of psychoperceptual adverse effects at 15, 30, and 60 min post drug administration. Two patients in the ketamine group and one in the morphine group experienced brief desaturation episodes. There were no statistically significant differences with respect to changes in vital signs and need for rescue medication.

CONCLUSION: SDK administered at 0.3 mg/kg over 15 min provides analgesic efficacy comparable to morphine for short-term treatment of acute pain in the geriatric ED patients but results in higher rates of psychoperceptual adverse effects.

ClinicalTrials.gov Registration #: NCT02673372.

Mil Med. 2018 May 24. doi: 10.1093/milmed/usy121. [Epub ahead of print]

# A non-comparative prospective pilot study of ketamine for sedation in adult septic shock.

Reese J, Sullivan V, Boyer N, Mount C

Introduction: Sedation and analgesia in the intensive care unit (ICU) for patients with sepsis can be challenging. Opioids and benzodiazepines can lower blood pressure and decrease respiratory drive. Ketamine is an N-methyl-D-aspartate (NMDA) receptor antagonist that provides both amnesia and analgesia without depressing respiratory drive or blood pressure. The purpose of this pilot study was to assess the effect of ketamine on the vasopressor requirement in adult patients with septic shock requiring mechanical ventilation.

Materials and Methods: We conducted a two-phase study in a multi-disciplinary adult ICU at a tertiary medical center. The first phase was a retrospective chart review of patients admitted with septic shock between July 2010 and July 2011; 29 patients were identified for a historical control group. The second phase was a prospective, non-randomized, open-label pilot study. Patients were eligible for inclusion if they were 18-89 yr of age with a diagnosis of septic shock, who also required mechanical ventilation for at least 24 h, concomitant sedation, and vasopressor therapy. Pregnant patients, patients in the peri-operative timeframe, and patients with acute coronary syndrome were excluded. Patients enrolled in the phase two pilot study received ketamine as the primary sedative. Ketamine was administered as a 1-2 mg/kg IV bolus, then as a continuous infusion starting at 5 mcg/kg/min, titrated 2 mcg/kg/min every 30 min as needed to obtain a Richmond Agitation Sedation Scale (RASS) goal of -1 to -2. If continuous sedation was still required after 48 h, patients were transitioned off ketamine and sedative strategy reverted to usual ICU sedation protocol. The primary outcome was the dose of vasopressor required at 24, 48, 72 and 96 h after enrollment. Secondary outcomes included cumulative ketamine dose, additional sedative and analgesics used, cumulative sedative and analgesic dosing at all time periods, corticosteroid use, days of mechanical ventilation, ICU LOS, hospital LOS, and mortality. Contiguous data were analyzed with unpaired t-tests and categorical data were analyzed with two-tailed, Fisher's exact test. This study was approved by our Institutional Review Board.

Results: From January 2012 to April 2015, a total of 17 patients were enrolled. Patient characteristics were similar in the control and study group. Ketamine was discontinued in one patient due to agitation at 36 h. There was a trend towards decreased norepinephrine and vasopressin use in the study group at all time periods. Regarding secondary outcomes, the study group received less additional analgesia with fentanyl at 24 and 48 h (p < 0.001), and less additional sedation with lorazepam, midazolam or dexmedetomidine at 24 h (p = 0.015).

Conclusion: This pilot study demonstrated a trend towards decreased vasopressor dose, and decreased benzodiazepine and opiate use when ketamine is used as the sole sedative. The limitations to our study include a small sample size and those inherent in using a retrospective control group. Our findings should be further explored in a large, randomized prospective study.

Wilderness Environ Med. 2018 Jun;29(2):211-214. doi: 10.1016/j.wem.2018.01.009. Epub 2018 Mar 22.

# A survey of wilderness medicine analgesia practice patterns.

Schauer S, Naylor J, Brown D, Gibbons R, Syndergaard I, Cushing T

INTRODUCTION: In 2014, the Wilderness Medical Society (WMS) published guidelines for the treatment of acute pain in remote settings. We surveyed wilderness medicine providers on self-reported analgesia prescribing practices.

METHODS: We conducted a prospective, anonymous survey. Respondents were recruited from the WMS annual symposium in 2016. All willing attendees were included.

RESULTS: During the symposium, we collected a total of 124 surveys (68% response rate). Respondent age was 42±12 (24-79) years (mean±SD with range), 58% were male, and 69% reported physician-level training. All respondents had medical training of varying levels. Of the physicians reporting a specialty, emergency medicine (59%, n=51), family medicine (13%, n=11), and internal medicine (8%, n=7) were reported most frequently. Eighty-one (65%) respondents indicated they prefer a standardized pain assessment tool, with the 10-point numerical rating scale being the most common (54%, n=67). Most participants reported preferring oral acetaminophen (81%, n=101) or nonsteroidal anti-inflammatory drugs (NSAID) (91%, n=113). Of those preferring NSAID, most reported administering acetaminophen as an adjunct (82%, n=101). Ibuprofen was the most frequently cited NSAID (71%, n=88). Of respondents who preferred opioids, the most frequently preferred opioid was oxycodone (26%, n=32); a lower proportion of respondents reported preferring oral transmucosal fentanyl citrate (9%, n=11). Twenty-five (20%, n=25) respondents preferred ketamine.

CONCLUSIONS: Wilderness medicine practitioners prefer analgesic agents recommended by the WMS for the treatment of acute pain. Respondents most frequently preferred acetaminophen and NSAIDs.

Emerg Med Australas. 2018 Jun;30(3):406-411

# Prehospital analgesic choice in injured patients does not impact on rates of vomiting: experience from a New South Wales primary retrieval service.

Zhang M, Cowan T Smiles J, Morgan M, Armstrong J, Goswami C, Sewell C.

OBJECTIVE: This study aimed to explore the analgesic regimes adopted in our contemporary retrieval practice and the incidence of vomiting in ED after prehospital analgesic use.

METHOD: A retrospective review was conducted on trauma patients retrieved by the Hunter Primary Retrieval Service in the Hunter New England Local Health District, New South Wales, Australia, during 2015.

RESULTS: Of the 379 patients attended by the service in 2015, 196 of them (mean age 38.6, SD 19.68, years) were selected for this review. Morphine was the most commonly used analgesic (mean 68.37%; 95% CI 61.36-74.81%), followed by fentanyl (mean 48.47%; 95% CI 41.29-55.70%) and ketamine (mean 34.18%; 95% CI 27.57-41.28%). Fourteen (7.14%, 95% CI 3.96-11.69%) patients vomited either prehospital or within the ED. Patients in both the emesis and the non-emesis group were comparable in demographics. None of the three studied analgesics were observed to be significantly associated with higher risk of vomiting than the others in this review, although a higher dose of fentanyl was given to the non-emesis group (P = 0.04).

CONCLUSIONS: The frequency of vomiting in the retrieved patients observed in our study was less than previously reported in the literature. Opioids still prevailed over ketamine as the preferred initial analgesic, with ketamine most commonly used as an adjunct. Multi-centre trials in this field would be preferable in future in view of the relatively low incidence of vomiting in retrieved trauma patients.