Low-dose ketamine vs morphine for acute pain in the ED: a randomized controlled trial

Comparison of Nebulized Ketamine to Intravenous Subdissociative Dose Ketamine for Treating Acute Painful Conditions in the Emergency Department: A Prospective, Randomized, Double-Blind, Double-Dummy Controlled Trial

STUDY OBJECTIVE

We aimed to assess and compare the analgesic efficacy and adverse effects of intravenous subdissociative-dose ketamine to nebulized ketamine in emergency department (ED) patients with acute painful conditions.

METHODS

We conducted a prospective, randomized, double-blind, double-dummy clinical trial in adult patients (ages 18 and older) with a numerical rating scale pain score of ≥5. We randomized subjects to receive either a single dose of 0.3 mg/kg of intravenous (IV) ketamine or 0.75 mg/kg of nebulized ketamine through a breath-actuated nebulizer. Primary outcome was the difference in pain scores on the numerical rating scale between groups at 30 minutes postmedication administration. The secondary outcomes included the need for rescue analgesia, occurrences of adverse events in each group, and the difference in pain scores at 15, 30, 60, 90, and 120 minutes. We calculated a 95% confidence interval (CI) for a mean difference at 30 minutes, with a minimum clinically important difference set at 1.3 points.

RESULTS

We enrolled 150 subjects (75 per group). Mean pain scores through numerical rating scale were 8.2 for both groups at baseline, which decreased to 3.6 and 3.8 at 30 minutes, yielding a mean difference of 0.23 (95% CI -1.32 to 0.857). We observed no clinically concerning changes in vital signs. No serious adverse events occurred in any of the groups throughout the study period.

CONCLUSION

We found no difference between the administration of IV and nebulized ketamine for the short-term treatment of moderate to severe acute pain in the ED, with both treatments providing a clinically meaningful reduction in pain scores at 30 minutes.

Ketamine Use for Palliative Care in the Austere Environment: Is Ketamine the Path Forward for Palliative Care

The goal of palliative care is to focus on the holistic needs of the patient and their family versus the pathology of the patient's diagnosis to reduce the stress of illness. U.S. servicemembers deployed to austere environments worldwide have significantly less access to palliative care than in military treatment facilities in the U.S. Preparation for future conflicts introduces the concept of prolonged medical management for an environment where urgent casualty evacuation is impossible. Ketamine is currently widely used for analgesia and anesthesia in the care of military service members and its use has increased in combat zones of Iraq and Afghanistan due to the favorable preservation of respiratory function, minimal changes in hemodynamics, and lower pain scores compared to opioids. Ketamine acts as a non-competitive antagonist on N-methyl-D aspartate (NMDA) receptors. Its anesthesia and analgesic effects are complex and include both presynaptic and postsynaptic neurons in brain and spinal cord. The use of palliative care to minimize suffering should not be withheld due to the logistical boundaries of austere military environments or lack of guidelines for recommended use. The use of ketamine for palliative care is a new clinical management strategy to provide both sedation and pain management for an acute pain crisis or comfort measures for the terminally ill. This makes ketamine an attractive consideration for palliative care when managing critically wounded patients for an extended time.

Low-dose ketamine versus morphine in the treatment of acute pain in the emergency department: A meta-analysis of 15 randomized controlled trials

OBJECTIVE

To compare the effectiveness and safety of ketamine and morphine in adult patients with acute pain in emergency department (ED) by using a meta-analysis method.

METHODS

This study was based on the Cochrane methodology for conducting a meta-analysis. Only randomized controlled trials (RCTs) were eligible for this study, with an experimental group that received low-dose ketamine and a control group that received morphine. The participants were adults who had acute pain in the ED. The primary outcome measures were the numeric rating scale (NRS) and visual analog scale (VAS). The secondary outcome measures were the complete resolution of pain, NRS reduction ≥3 points, NRS reduction ≥50% or 60%, change of NRS score, change of VAS score, rescue analgesia, satisfaction and adverse events. Subgroup analysis was performed for studies with intravenous and intranasal administration of ketamine. The Review Manager Database was used to analyze the included studies.

RESULTS

15 RCTs involving 1768 patients were included. The ketamine group had lower NRS scores than morphine group at 30 min (MD, -0.77 [95% CI, -0.93 to -0.61]; p < 0.00001), while the morphine had better analgesic effects at 120 min after treatment (MD, 0.33 [95% CI, 0.15 to 051]; p = 0.0003). The subjects of complete resolution of pain in the ketamine group performed better than those in the morphine group at 15 min (RR 3.18, 95% CI 1.75 to 5.78; p = 0.0001). Compared with the morphine group, the ketamine group had a lower incidence of adverse events requiring intervention (RR, 0.34 [95% CI, 0.18 to 0.66]; p = 0.001). Subgroup analysis of intravenous ketamine showed that ketamine had lower VAS score than the morphine group at 30 min. However, also on the 30-min VAS score, intranasal ketamine analgesia was less effective than morphine.

CONCLUSIONS

Ketamine had better analgesic effects in the early stages after treatment, while morphine maintained more durable effects. Compared with morphine, ketamine had a lower incidence of adverse events requiring intervention. The results of subgroup analysis showed that intravenous administration of ketamine was more effective than intranasal administration.

A systematic review and meta-analysis comparing the efficacy and safety of ketamine versus morphine for the treatment of acute pain

INTRODUCTION

Ketamine is reported as a potent opioid alternative that provides significant reduction in pain with no severe adverse events. However, some studies didn't find its use satisfactory and reported less reduction in pain score with ketamine. The purpose of this study is to compare the efficacy and safety of ketamine versus morphine for the treatment of acute pain in emergency situations.

EVIDENCE ACQUISITION

The PubMed, MEDLINE, PsycINFO EMBASE, Cochrane Library, PROSPERO registry platform, and ClinicalTrials.gov websites were queried in accordance with the PRISMA guidelines in order to locate relevant studies. According to the predefined PICOS criteria, articles were included and event data pertaining to changes in Visual Analog Scale or Numeric Rating Scale pain scales were extracted. Using RevMan and MedCalc, a meta-analysis was conducted to compare the effects of ketamine and morphine for the treatment of acute pain.

EVIDENCE SYNTHESIS

Twelve studies met the criteria for inclusion in this meta-analysis. Ketamine was found to be more effective than morphine at reducing pain scores, with an odds ratio of 0.60 (95% CI 0.48 to 0.76). Similarly, no severe adverse events related to ketamine were reported in any study, and it has a low-risk ratio of 0.78 (95% CI 0.70 to 0.87). Egger's Test P values (0.3052) and Begg's Test P values (0.3869) indicate a low risk of bias, and the Bland-Altman plot demonstrates a high degree of concordance.

CONCLUSIONS

Ketamine is a potent and effective alternative to morphine for the management of acute pain, and it reduces pain score significantly with minimal side effects.

Comparison of acetaminophen, ketamine, or ketorolac versus morphine in the treatment of acute renal colic: A network meta-analysis

BACKGROUND

Renal colic is a disease in which a calculus obstructs the urinary tract, resulting in severe pain do ureteric peristaltic movements. Other symptoms, such as hematuria, nausea, and vomiting, may accompany the pain. This network meta-analysis aimed to compare the efficacy and safety of different analgesic agents for the treatment of acute renal colic.

METHODS

Medline, Embase, and CENTRAL databases were searched. Randomized controlled trials (RCTs) that compared different analgesic agents, either alone or in combination were included. For the management of acute renal colic, analgesic agents were selected based on the current standard medical practice. The medications included intravenous acetaminophen, ketamine, ketorolac, and morphine. This study sought to evaluate the pain score on the visual analog scale (VAS) at 15, 30, and 60 min; adverse events; and the utilization of rescue therapy. The efficacy of different analgesic agents was explored through a frequentist network meta-analysis using the Netmeta statistical package in R software. All treatments were ranked using the Netrank function, yielding P-scores.

RESULTS

Twelve RCTs were deemed eligible. As per the P-scores, acetaminophen was the most effective in reducing pain score at 15 min (P-score = 0.74). Ketorolac was the most effective in reducing the pain score at 30 and 60 min (P-score = 0.84) (P-score = 0.99), whereas morphine was the least effective (P-score = 0.07). Moreover, morphine was correlated with the highest odds of adverse events after treatment (P-score = 0.89). Morphine was the most frequently required rescue therapy in cases of suboptimal pain relief (P-score = 0.96).

CONCLUSION

This network meta-analysis demonstrated that ketorolac and acetaminophen were the most effective analgesic agents according to the pain score. Morphine showed the highest adverse event profile and the highest rate at which rescue therapy was required for the management of acute renal colic.

Low-dose ketamine or opioids combined with propofol for procedural sedation in the emergency department: a systematic review

Procedural sedation is routinely performed for procedures in the emergency department (ED). Propofol is a commonly used sedative, frequently combined with an opioid or low-dose ketamine as an analgesic. However, there is still controversy on the optimal combination of agents in current guidelines. The objective of this systematic review is to identify and present studies comparing low-dose ketamine to opioids when combined with propofol for procedural sedation in the ED and to describe the dosing regimen, observed efficacy, and side effects. For this systematic review, following the Preferred Reporting Items for Systematic Review and Meta-Analysis guidelines, EMBASE and PubMed databases were searched. Studies comparing propofol with opioids versus propofol with low-dose (es)ketamine in patients undergoing procedural sedation for procedures in the ED were included. Analyses were descriptive because of the high heterogeneity among included studies. The outcomes were dosing regimen, efficacy of analgesia, efficacy of sedation depth, efficacy of recovery and (adverse) events. We included four out of 2309 studies found in the literature search. Overall, the studies had a low risk of bias, but the Grading of Recommendations Assessment, Development, and Evaluation evidence profile was downgraded due to the imprecision and inconsistency of the studies. All studies compared low-dose ketamine with fentanyl. Dosing ranged from 0.3 to 1.0 mg/kg (ketamine), 1.0-1.5 μg/kg (fentanyl) and 0.4-1.0 mg/kg (propofol). The efficacy of analgesia was measured by two studies, one favoring the fentanyl group, and one favoring the ketamine group. The efficacy of sedation depth was measured by one study, with the fentanyl group having a deeper sedation score. Two studies showed shorter recovery time with low-dose ketamine. One study showed a higher incidence of cardio-respiratory clinical events and interventions in the fentanyl group. Two studies showed significant differences of overall sedation events in the fentanyl group. One study did not find any significant differences of the incidence of sedation events. This systematic review did not provide sufficient evidence that the combination of low-dose ketamine and propofol is associated with a shorter recovery time and fewer sedation events compared to the combination of opioids and propofol.

Efficacy of analgesic and sub-dissociative dose ketamine for acute pain in the emergency department

BACKGROUND

Acute pain accounts for over 70% of Emergency Department (ED) visits. Sub-dissociative dose ketamine (0.1-0.6 mg/kg) is safe and effective for the management of acute pain in the ED. However, the optimal dose of intravenous ketamine that provides effective analgesia and minimizes the risk of adverse effects has yet to be identified. The objective of this study was to describe an effective analgesia dose range of IV ketamine for acute pain in the ED.

METHODS

This multi-center, retrospective cohort study evaluated adult patients who received analgesic and sub-dissociative dose ketamine for the management of acute pain between May 5, 2018, and August 30, 2021, in 21 emergency departments at academic, community, and critical access hospitals across four states. Patients were excluded if they received ketamine for an indication other than pain, such as procedural sedation or intubation, or for whom there was incomplete documentation for the primary outcome. Patients who received a ketamine dose <0.3 mg/kg were stratified into the low-dose group, and those who received a dose of 0.3 mg/kg or higher to the high-dose group. The primary outcome was change in pain scores within 60 min using a standard 11-point numeric rating scale (NRS). Secondary outcomes included incidence of adverse effects and use of rescue analgesics. Continuous variables were compared between dose groups using student t-test or Wilcoxon Rank-Sum test. Linear regression was used to assess the association between the change in NRS pain scores within 60 min and dose after adjusting for baseline pain, requiring an additional dose of ketamine, and receiving an opioid.

RESULTS

From 3796 patient encounters screened for receipt of ketamine, 384 patients met inclusion criteria including 258 in the low-dose group, and 126 in the high-dose group. The primary reason for exclusion was incomplete documentation of pain scores, or ketamine used for sedation. Median baseline pain scores were 8.2 in the low-dose group and 7.8 in the high-dose group (difference 0.5; 95% CI 0 to 1, p = 0.04). Both groups demonstrated significant reductions in their mean NRS pain scores within 60 min following the first administration of IV ketamine. There were no differences in the change in pain scores between both groups (-2.2 vs -2.6, mean difference 0.4, 95% CI -0.4 to 1.1, p = 0.34). Use of rescue analgesics (40.7% vs 36.5%, p = 0.43) and adverse effects were similar between groups, including early discontinuation of the ketamine infusion (37.2% vs. 37.3%, p = 0.99). Overall, the most common adverse effects were agitation (7.3%) and nausea (7.0%).

CONCLUSION

The analgesic efficacy and safety of high-dose sub-dissociative ketamine (≥0.3 mg/kg) was not superior to low-dose (< 0.3 mg/kg) for the management of acute pain in the ED. Low-dose ketamine <0.3 mg/kg is an effective and safe pain management strategy in this population.

The Pain Management of Trauma Patients in the Emergency Department

The vast majority of injured patients suffer from pain. Systematic assessment of pain on admission to the emergency department (ED) is a cornerstone of translating the best treatment strategies for patient care into practice. Pain must be measured with severity scales that are validated in clinical practice, including for specific populations (such as children and older adults). Although primary care ED of trauma patients focuses on resuscitation, diagnosis and treatment, pain assessment and management remains a critical element as professionals are not prepared to provide effective and early therapy. To date, most EDs have pain assessment and management protocols that take into account the patient's hemodynamic status and clinical condition and give preference to non-pharmacological approaches where possible. When selecting medications, the focus is on those that are least disruptive to hemodynamic status. Pain relief may still be necessary in hemodynamically unstable patients, but caution should be exercised, especially when using opioids, as absorption may be impaired or shock may be exacerbated. The analgesic dose of ketamine is certainly an attractive option. Fentanyl is clearly superior to other opioids in initial resuscitation and treatment as it has minimal effects on hemodynamic status and does not cause central nervous system depression. Inhaled analgesia techniques and ultrasound-guided nerve blocks are also increasingly effective solutions. A multimodal pain approach, which involves the use of two or more drugs with different mechanisms of action, plays an important role in the relief of trauma pain. All EDs must have policies and promote the adoption of procedures that use multimodal strategies for effective pain management in all injured patients.

Narrative Review: Low-Dose Ketamine for Pain Management

Pain is the leading cause of medical consultations and occurs in 50-70% of emergency department visits. To date, several drugs have been used to manage pain. The clinical use of ketamine began in the 1960s and it immediately emerged as a manageable and safe drug for sedation and anesthesia. The analgesic properties of this drug were first reported shortly after its use; however, its psychomimetic effects have limited its use in emergency departments. Owing to the misuse and abuse of opioids in some countries worldwide, ketamine has become a versatile tool for sedation and analgesia. In this narrative review, ketamine's role as an analgesic is discussed, with both known and new applications in various contexts (acute, chronic, and neuropathic pain), along with its strengths and weaknesses, especially in terms of psychomimetic, cardiovascular, and hepatic effects. Moreover, new scientific evidence has been reviewed on the use of additional drugs with ketamine, such as magnesium infusion for improving analgesia and clonidine for treating psychomimetic symptoms. Finally, this narrative review was refined by the experience of the Pain Group of the Italian Society of Emergency Medicine (SIMEU) in treating acute and chronic pain with acute manifestations in Italian Emergency Departments.

Subanaesthetic single-dose ketamine as an adjunct to opioid analgesics for acute pain management in the emergency department: a systematic review and meta-analysis

OBJECTIVE

To evaluate the effectiveness of a subanaesthetic single-dose ketamine (SDK) as an adjunct to opioids for acute pain in emergency department (ED) settings.

DESIGN

Systematic review and meta-analysis.

METHODS

A systematic search was performed in MEDLINE, Embase, Scopus and Web of Science through March 2022. Randomised controlled trials (RCTs) that investigated SDK as an adjunct to opioids in adult patients for any painful condition in ED settings were selected. Two reviewers screened studies, extracted data and assessed study quality. Data were pooled using random-effects models. The primary outcome was mean pain intensity score measured at baseline, >0-15 min, >15-30 min, >30-45 min, 60 min, 90 min and 120 min. Secondary outcomes included need for rescue analgesia, adverse events and patient satisfaction. Results were reported as mean differences (MDs) and risk ratios. Statistical heterogeneity was calculated using the I 2 statistic.

RESULTS

Eight RCTs were included (n=903). Studies were judged to be at moderate to high risk of bias. Mean pain intensity scores were significantly lower 60 min after study drug administration favouring adjuvant SDK (MD -0.76; 95% CI -1.19 to -0.33), compared with opioids alone. There was no evidence of differences in mean pain intensity scores at any other time point. Patients who received adjuvant SDK were less likely to require rescue analgesia, no more likely to experience serious side effects and had higher satisfaction scores, compared with opioids alone.

CONCLUSIONS

Available evidence suggests adjuvant SDK can have an effect on lowering pain intensity scores. Although reduction of pain scores was not clinically significant, the combination of reduced pain intensity and reduced opioid requirements suggest the results could be clinically important and support the potential utility of SDK as an adjunct to opioids to treat acute pain in adult ED patients. However, current evidence is limited and higher quality RCTs are needed.

PROSPERO REGISTRATION NUMBER

CRD42021276708.

The Effectiveness of Ketamine Versus Opioids in Patients With Acute Pain in the Emergency Department: A Systematic Review and Meta-Analysis

Opioids are the mainstay of treatment for acute pain in the emergency department. However, its misuse led to the investigation of alternative effective analgesic options for acute pain complaints such as ketamine. Therefore, this systematic review and meta-analysis aimed to determine the effectiveness of ketamine in comparison to opioids in the management of acute pain. This was a systematic review and meta-analysis of randomized controlled trials comparing ketamine to opioids for the relief of acute pain in the ED. Eligible studies were identified by searching the following electronic databases: Medline, Embase, and Central. Studies utilizing either the visual analog scale (VAS) or the numeric rating scale (NRS) for pain scoring in ketamine vs opioids were included. The revised Cochrane risk-of-bias tool for randomized trials was utilized. A random-effects model was performed, and all outcomes were pooled by the inverse variance weighting method. The total number of studies that met the criteria of systematic reviews was nine of which seven of them were included in the meta-analysis with 789 participants. The overall effect of NRS trials was the standardized mean difference (SMD) = -0.07, 95% confidence interval (CI) -0.31 to 0.17, P-value = 0.56, I² =85%. While VAS trials showed an overall effect of SMD = -0.02, 95% CI -0.22 to 0.18, P = 0.84, I² = 59%). Moreover, higher adverse events were reported in opioids; however, this was not statistically significant (SMD = 1.23, 95% CI 0.93-1.64, P = 0.15, I2 =38%). Ketamine for immediate pain relief at 15 minutes could be an effective alternative to opioids, but its overall effect in comparison to opioids for improving the pain has not shown a statistically significant difference. There was high heterogeneity in the included studies; thus, a sub-group analysis was performed.

Ketamine decreased opiate use in US military combat operations from 2010 to 2019

BACKGROUND

Ketamine is a dissociative anaesthetic currently used in a variety of healthcare applications. Effects are dose dependent and cause escalating levels of euphoria, analgesia, dissociation and amnesia. Ketamine can be given via intravenous, intramuscular, nasal, oral and aerosolised routes. A 2012 memorandum and the 2014 Tactical Combat Casualty Care (TCCC) guidelines included ketamine as part of the 'Triple Option' for analgesia. This study investigated the effect of ketamine adoption by the US military TCCC guidelines on opioid use between 2010 and 2019.

METHODS

This was a retrospective review of deidentified Department of Defense Trauma Registry data. The study was approved by the Institutional Review Board of Naval Medical Center San Diego (NMCSD) and facilitated by a data sharing agreement between NMCSD and the Defense Health Agency. Patient encounters from all US military operations from January 2010 to December 2019 were queried. All administrations of any pain medications via any route were included.

RESULTS

5965 patients with a total of 8607 pain medication administrations were included. Between 2010 and 2019, the yearly percentage of ketamine administrations rose from 14.2% to 52.6% (p<0.001). The percentage of opioid administrations decreased from 85.8% to 47.4% (p<0.001). Among the 4104 patients who received a single dose of pain medication, the mean Injury Severity Score for those who received ketamine was higher than for those who received an opioid (mean=13.1 vs 9.8, p<0.001).

CONCLUSION

Military opioid use declined as ketamine use increased over 10 years of combat. Ketamine is generally used first for more severely injured patients and has increasingly been employed by the US military as the primary analgesic for combat casualties.

Comparing the Effects of Low-Dose Ketamine, Fentanyl, and Morphine on Hemorrhagic Tolerance and Analgesia in Humans

Hemorrhage is a leading cause of preventable battlefield and civilian trauma deaths. Ketamine, fentanyl, and morphine are recommended analgesics for use in the prehospital (i.e., field) setting to reduce pain. However, it is unknown whether any of these analgesics reduce hemorrhagic tolerance in humans. We tested the hypothesis that fentanyl (75 µg) and morphine (5 mg), but not ketamine (20 mg), would reduce tolerance to simulated hemorrhage in conscious humans. Each of the three analgesics was evaluated independently among different cohorts of healthy adults in a randomized, crossover (within drug/placebo comparison), placebo-controlled fashion using doses derived from the Tactical Combat Casualty Care Guidelines for Medical Personnel. One minute after an intravenous infusion of the analgesic or placebo (saline), we employed a pre-syncopal limited progressive lower-body negative pressure (LBNP) protocol to determine hemorrhagic tolerance. Hemorrhagic tolerance was quantified as a cumulative stress index (CSI), which is the sum of products of the LBNP and the duration (e.g., [40 mmHg x 3 min] + [50 mmHg x 3 min] …). Compared with ketamine (p = 0.002 post hoc result) and fentanyl (p = 0.02 post hoc result), morphine reduced the CSI (ketamine (n = 30): 99 [73-139], fentanyl (n = 28): 95 [68-130], morphine (n = 30): 62 [35-85]; values expressed as a % of the respective placebo trial's CSI; median [IQR]; Kruskal-Wallis test p = 0.002). Morphine-induced reductions in tolerance to central hypovolemia were not well explained by a prediction model including biological sex, body mass, and age (R2=0.05, p = 0.74). These experimental data demonstrate that morphine reduces tolerance to simulated hemorrhage while fentanyl and ketamine do not affect tolerance. Thus, these laboratory-based data, captured via simulated hemorrhage, suggest that morphine should not be used for a hemorrhaging individual in the prehospital setting.

Ultrasound-guided selective peripheral nerve block compared with the sub-dissociative dose of ketamine for analgesia in patients with extremity injuries

STUDY OBJECTIVE

To compare the analgesic efficacy of ultrasound-guided selective peripheral nerve block (PNB) and sub-dissociative dose ketamine (SDK) for management of acute pain in patients with extremity injuries presenting to the emergency department (ED).

METHODS

This prospective, open-label randomized clinical trial was conducted in the ED of a tertiary care Institute. The patients were provided with either ultrasound-guided selective PNB or SDK. The primary outcome was a reduction in pain in numerical rating scale (NRS) by at least 3 points without rescue analgesia. The secondary outcomes were the need for rescue analgesia, adverse events, and patient satisfaction on either arm.

RESULTS

A total of 111 patients with isolated traumatic extremity injuries were included in the final analysis. The NRS score was significantly lower in the PNB group compared to the SDK group at 30, 60,120, 180-, and 240-min post-intervention [group ∼ time interaction, F (5, 647) = 21.53, p ≤ 0.001]. All the patients in the PNB group exhibited primary outcome (NRS ≥3 reductions) at 30 min post-intervention compared with 36 (65%) in the SDK group [-1.02(-1.422,0.622)]. Rescue analgesia was required in 10 (18%) patients in the SDK group compared to none in the PNB group [0.663(0.277,1.050)]. The decrease in NRS score from baseline at 30 min was significantly higher in PNB groups compared to the SDK group [-2.166(-2.640, -1.692)]. The most common side effect reported in the SDK group was dizziness 35(64%), followed by nausea 15(27%). None of the patients in the PNB group reported any complications. Patient satisfaction was higher in the PNB group than SDK group.

CONCLUSION

The study provides evidence that ultrasound-guided PNB is superior to SDK in terms of its analgesic efficacy in the management of acute pain due to extremity injuries and is associated with higher patient satisfaction. The need for rescue analgesia was significantly less in the PNB group. SDK was associated with a high incidence of dizziness and nausea.

Lidocaine and Ketamine Infusions as Adjunctive Pain Management Therapy: A Retrospective Analysis of Clinical Outcomes in Hospitalized Patients Admitted for Pain Related to Sickle Cell Disease

Objective

In this study, we aim to evaluate the efficacy of adjunctive lidocaine and ketamine infusions for opioid reduction in the treatment of sickle cell disease in patients with vaso-occlusive crisis (VOC).

Design

We retrospectively reviewed a cohort of 330 adult sickle-cell crisis hospital encounters with 68 patients admitted to our institution from July 2017 to August 2018.

Methods

Upon institutional IRB approval, we obtained initial data from billing records and performed chart reviews to obtain pain scores and confirm total opioid consumption. If provided by the acute pain consultation service, the patients received either a lidocaine or a ketamine infusion of 0.5–2 mg/min or 2–3 mcg/kg, respectively, for a maximum of 24–48 h. We compared the change in opioid consumption before and after infusion therapy to patients that did not receive ketamine or lidocaine.

Results

Compared to patients that did not receive infusion therapy, ketamine and lidocaine accounted for respective relative decreases of 28 and 23% in average daily morphine consumption (p = 0.02). Patients that received either infusion were 3 to 4 times more likely to decrease their opioid consumption independent of treatment length or baseline opioid doses (p < 0.01). Ketamine and lidocaine therapies were not associated with change in pain scores. When a patient had multiple admissions, opioid reduction was strongly correlated with initiation of infusions in the later visits.

Conclusion

Both ketamine and lidocaine infusion therapies are effective in reducing opioid consumption for patients with vaso-occlusive crisis. Lidocaine infusion is emerging as an agent for stabilizing opioid doses in VOC for patients with high daily MME.

Novel uses of ketamine in the emergency department

INTRODUCTION

: Ketamine is gaining renewed interest among healthcare providers due to its novel clinical applications in the emergency department (ED) setting.

AREAS COVERED

: This article provides a comprehensive discussion of ketamine's pharmacological properties, including safety profile and adverse effects, in addition to an overview of current evidence for ketamine (racemic formulation) in the management of ED patients with acute agitation, pain, and depression/suicide ideation.

EXPERT OPINION

: Ketamine is an effective adjunct to opioids, providing greater pain relief than morphine alone. As an analgesic agent, administration of ketamine (0.1-0.3 mg/kg IV) alone can provide analgesia similar to that of morphine in patients with acute visceral and musculoskeletal pain. Moreover, ketamine provides equal analgesic efficacy to morphine in a variety of chronic painful conditions including pain associated with cancer, vaso-occlusive pain crisis associated with sickle cell disease, and in patients with high opioid tolerance and/or opioid dependency. Available literature shows that ketamine (1-2mg/kg IV or 4-5 mg/kg IM) is a safe, rapid (<5 minutes) and effective tranquilization agent for ED patients with acute agitation. Finally, there is growing evidence that suggests ketamine may have a potential utility in the management of patients with self-harm ideation or acute depressive episodes. Intravenous infusion of ketamine (0.5 mg/kg over 40 mins) has been shown to produce an antidepressant effect and decrease in suicidal ideation within 4 hours with effects lasting up to one week.

Low-dose morphine reduces pain perception and blood pressure, but not muscle sympathetic outflow, responses during the cold pressor test

Our knowledge about how low-dose (analgesic) morphine affects autonomic cardiovascular regulation is primarily limited to animal experiments. Notably, it is unknown if low-dose morphine affects human autonomic cardiovascular responses during painful stimuli in conscious humans. Therefore, we tested the hypothesis that low-dose morphine reduces perceived pain and subsequent sympathetic and cardiovascular responses in humans during an experimental noxious stimulus. Twenty-nine participants (14 females/15 males; 29 ± 6 yr; 26 ± 4 kg·m-2, means ± SD) completed this randomized, crossover, placebo-controlled trial during two laboratory visits. During each visit, participants completed a cold pressor test (CPT; hand in ∼0.4°C ice bath for 2 min) before and ∼35 min after drug/placebo administration (5 mg iv morphine or saline). We compared pain perception (100 mm visual analog scale), muscle sympathetic nerve activity (MSNA; microneurography; 14 paired recordings), and beat-to-beat blood pressure (BP; photoplethysmography) between trials (at both pre- and postdrug/placebo time points) using paired, two-tailed t tests. Before drug/placebo infusion, perceived pain (P = 0.92), ΔMSNA burst frequency (n = 14, P = 0.21), and Δmean BP (P = 0.39) during the CPT were not different between trials. After the drug/placebo infusion, morphine versus placebo attenuated perceived pain (morphine: 43 ± 20 vs. placebo: 57 ± 24 mm, P < 0.001) and Δmean BP (morphine: 10 ± 7 vs. placebo: 13 ± 8 mmHg, P = 0.003), but not ΔMSNA burst frequency (morphine: 10 ± 11 vs. placebo: 13 ± 11 bursts·min-1, P = 0.12), during the CPT. Reductions in pain perception and Δmean BP were only weakly related (r = 0.34, P = 0.07; postmorphine CPT minus postplacebo CPT). These data provide valuable information regarding how low-dose morphine affects autonomic cardiovascular responses during an experimental painful stimulus.NEW & NOTEWORTHY In this randomized, crossover, placebo-controlled trial, we found that low-dose morphine administration reduced pain perception and blood pressure responses during the cold pressor test via attenuated increases in heart rate and cardiac output. We also determined that muscle sympathetic outflow responses during the cold pressor test seem to be unaffected by low-dose morphine administration. Finally, our exploratory analysis suggests that biological sex does not influence morphine-induced antinociception in healthy adults.

Low-dose morphine reduces tolerance to central hypovolemia in healthy adults without affecting muscle sympathetic outflow

Hemorrhage is a leading cause of preventable battlefield and civilian trauma deaths. Low-dose (i.e., an analgesic dose) morphine is recommended for use in the prehospital (i.e., field) setting. Morphine administration reduces hemorrhagic tolerance in rodents. However, it is unknown whether morphine impairs autonomic cardiovascular regulation and consequently reduces hemorrhagic tolerance in humans. Thus, the purpose of this study was to test the hypothesis that low-dose morphine reduces hemorrhagic tolerance in conscious humans. Thirty adults (15 women/15 men; 29 ± 6 yr; 26 ± 4 kg·m-2, means ± SD) completed this randomized, crossover, double-blinded, placebo-controlled trial. One minute after intravenous administration of morphine (5 mg) or placebo (saline), we used a presyncopal limited progressive lower-body negative pressure (LBNP) protocol to determine hemorrhagic tolerance. Hemorrhagic tolerance was quantified as a cumulative stress index (mmHg·min), which was compared between trials using a Wilcoxon matched-pairs signed-rank test. We also compared muscle sympathetic nerve activity (MSNA; microneurography) and beat-to-beat blood pressure (photoplethysmography) during the LBNP test using mixed-effects analyses [time (LBNP stage) × trial]. Median LBNP tolerance was lower during morphine trials (placebo: 692 [473-997] vs. morphine: 385 [251-728] mmHg·min, P < 0.001, CI: -394 to -128). Systolic blood pressure was 8 mmHg lower during moderate central hypovolemia during morphine trials (post hoc P = 0.02; time: P < 0.001, trial: P = 0.13, interaction: P = 0.006). MSNA burst frequency responses were not different between trials (time: P < 0.001, trial: P = 0.80, interaction: P = 0.51). These data demonstrate that low-dose morphine reduces hemorrhagic tolerance in conscious humans. Thus, morphine is not an ideal analgesic for a hemorrhaging individual in the prehospital setting.NEW & NOTEWORTHY In this randomized, crossover, placebo-controlled trial, we found that tolerance to simulated hemorrhage was lower after low-dose morphine administration. Such reductions in hemorrhagic tolerance were observed without differences in MSNA burst frequency responses between morphine and placebo trials. These data, the first to be obtained in conscious humans, demonstrate that low-dose morphine reduces hemorrhagic tolerance. Thus, morphine is not an ideal analgesic for a hemorrhaging individual in the prehospital setting.

Opioid Sparing Effect of Ketamine in Military Pre-Hospital Pain Management - A Retrospective Study

BACKGROUND

Opioids are the most commonly used analgesics in acute trauma, but are limited by slow onset and significant adverse effects. Ketamine is an effective and widely used analgesic. This study was aimed to evaluate the effectiveness and opioid-sparing effects of ketamine when utilized in pre-hospital military trauma setting.

METHODS

A retrospective analysis of a pre-hospital military trauma registry between 2014 - 2020. Inclusion criteria were age ≥ 16 years, ≥2 documented pain assessments, at least one indicating severe pain, and administration of opioids and/or low-dose ketamine. Joint hypothesis testing was used to compare casualties who received opioids only to those who received ketamine on outcomes of pain score reduction and opioid consumption.

RESULTS

Overall, 382 casualties were included. 91 (24%) received ketamine (21 as a single analgesic), with a mean dose of 29 mg (SD 11). Mean reduction in pain scores (on an 11-point scale) was not significantly different; 4.3-point (2.8) reduction in the ketamine group and 3.7-points (2.4) in the opioid-only group (p = 0.095). Casualties in the ketamine group received a median of 10 mg (IQR 3.5, 25) of morphine equivalents (ME) compared with a median of 20 ME (10, 20) in the opioid-only group. In a multivariable multinomial logistic regression, casualties in the ketamine group were significantly more likely to receive a low (1-10 ME) rather than a medium (11-20 ME) dose of opioids compared to the opioid-only group (OR 0.032, CI 0.14 - 0.75).

CONCLUSIONS

The use of ketamine in the pre-hospital military setting as part of a pain management protocol was associated with a low rather than medium dose of opioids in a multivariable analysis, while the mean reduction in pain scores was not significantly different between groups. Using ketamine as a first-line agent may further reduce opioid consumption with a similar analgesic effect.

LEVELS OF EVIDENCE

Level IV, therapeutic/care management.

Managing acute pain in children presenting to the emergency department without opioids

Pediatric pain is challenging to assess and manage. Frequently underestimated in children, untreated pain may have consequences including increased fear, anxiety, and psychological issues. With the current opioid crisis, emergency physicians must be knowledgeable in both pharmacologic and non-pharmacologic approaches to address pain and anxiety in children that lead to enhanced patient cooperation and family satisfaction. This document focuses pain management and distress mitigation strategies for the brief diagnostic and therapeutic procedures commonly performed.

Efficacy and safety of ketamine in mechanically ventilated intensive care unit patients: a scoping review

Objectives: Mechanically ventilated patients account for about one-third of all admissions to the intensive care unit (ICU). Ketamine has been conditionally recommended to aid with analgesia in such patients, with low quality of evidence available to support this recommendation. We aimed to perform a narrative scoping review of the current knowledge of the use of ketamine, with a specific focus on mechanically ventilated ICU patients. Methods: We searched MEDLINE and EMBASE for relevant articles. Bibliographies of retrieved articles were examined for references of potential relevance. We included studies that described the use of ketamine for postoperative and emergency department management of pain and in the critically unwell, mechanically ventilated population. Results: There are few randomised controlled trials evaluating ketamine's utility in the ICU. The evidence is predominantly retrospective and observational in nature and the results are heterogeneous. Available evidence is summarised in a descriptive manner, with a division made between high dose and low dose ketamine. Ketamine's pharmacology and use as an analgesic agent outside of the ICU is briefly discussed, followed by evidence for use in the ICU setting, with particular emphasis on analgesia, sedation and intubation. Finally, data on adverse effects including delirium, coma, haemodynamic adverse effects, raised intracranial pressure, hypersalivation and laryngospasm are presented. Conclusions: Ketamine is used in mechanically ventilated ICU patients with several potentially positive clinical effects. However, it has a significant side effect profile, which may limit its use in these patients. The role of low dose ketamine infusion in mechanically ventilated ICU patients is not well studied and requires investigation in high quality, prospective randomised trials.

Non-inferiority of intranasal ketamine compared to intravenous morphine for musculoskeletal pain relief among older adults in an emergency department: a randomised controlled trial

OBJECTIVES

ketamine has potential advantages over morphine for musculoskeletal pain relief. The aim of this study was to compare the analgesic efficacy and safety of intranasal (IN) ketamine to intravenous (IV) morphine for older adults with musculoskeletal pain in the emergency department (ED).

METHODS

this was a non-inferiority, double-blind, randomised controlled trial of ED patients aged of 65 and older presenting with acute moderate to severe musculoskeletal pain defined as a score ≥5 on an 11-point numeric rating scale (NRS). Patients were randomly assigned to receive IN ketamine or IV morphine. The primary outcome was comparative reduction of NRS pain scores between ketamine and morphine groups at 30 min post-treatment. Secondary outcomes were incidence of adverse events and requirement for rescue therapy.

RESULTS

seventy-four patients were eligible for analysis (37 in the IN ketamine and 37 in the IV morphine group). Mean pain score at 30 min did not differ significantly between IN ketamine and IV morphine groups (6.03 versus 5.81). Similarly, the difference in mean NRS change from baseline between IN ketamine and IV morphine groups [(-2.14, 95% CI: -2.79 to -1.48) and (-0.81, 95% CI: -2.36 to -1.26) = -0.32, 95% CI: -1.17 to -0.52] did not reach the non-inferiority margin of 1.3. Adverse events and incidence of rescue therapy also did not differ between groups.

CONCLUSIONS

intranasal ketamine can provide a non-inferior analgesic effect compared to intravenous morphine for acute musculoskeletal pain in older adults with mild adverse effects and low incidence of rescue analgesic treatment.

A Case Report of Subanesthetic Ketamine Bolus and Infusion for Opioid Refractory Cancer Pain

Opioids and traditional adjuvant medications are frequently prescribed for the management of moderate to severe cancer pain with good effect. However, there are many cases, in which patients experience severe opioid refractory cancer pain. Ketamine is being used more frequently in the hospice and palliative setting to manage opioid refractory pain, although high-quality evidence regarding its effectiveness is lacking. It seems certain patients respond favorably to ketamine, while others experience no effect. Studies have not yet identified factors associated with a favorable response to ketamine. We present a case describing the successful treatment of high-dose opioid refractory cancer pain with a subanesthetic ketamine infusion and propose the novel use of a preinfusion test bolus of ketamine to identify patients who are likely to respond favorably to an infusion.

Opioids for Treatment of Pre-hospital Acute Pain: A Systematic Review

INTRODUCTION

Acute pain is a frequent symptom among patients in the pre-hospital setting, and opioids are the most widely used class of drugs for the relief of pain in these patients. However, the evidence base for opioid use in this setting appears to be weak. The aim of this systematic review was to explore the efficacy and safety of opioid analgesics in the pre-hospital setting and to assess potential alternative therapies.

METHODS

The PubMed, EMBASE, Cochrane Library, Centre for Reviews and Dissemination, Scopus, and Epistemonikos databases were searched for studies investigating adult patients with acute pain prior to their arrival at hospital. Outcomes on efficacy and safety were assessed. Risk of bias for each included study was assessed according to the Cochrane approach, and confidence in the evidence was assessed using the GRADE method.

RESULTS

A total of 3453 papers were screened, of which the full text of 125 was assessed. Twelve studies were ultimately included in this systematic review. Meta-analysis was not undertaken due to substantial clinical heterogeneity among the included studies. Several studies had high risk of bias resulting in low or very low quality of evidence for most of the outcomes. No pre-hospital studies compared opioids with placebo, and no studies assessed the risk of opioid administration for subgroups of frail patients. The competency level of the attending healthcare provider did not seem to affect the efficacy or safety of opioids in two observational studies of very low quality. Intranasal opioids had a similar effect and safety profile as intravenous opioids. Moderate quality evidence supported a similar efficacy and safety of synthetic opioid compared to morphine.

CONCLUSIONS

Available evidence for pre-hospital opioid administration to relieve acute pain is scarce and the overall quality of evidence is low. Intravenous administration of synthetic, fast-acting opioids may be as effective and safe as intravenous administration of morphine. More controlled studies are needed on alternative routes for opioid administration and pre-hospital pain management for potentially more frail patient subgroups.

Interactions between Ketamine and Magnesium for the Treatment of Pain: Current State of the Art

BACKGROUND

Over the past three decades, NMDA-receptor antagonists have been shown to be efficient drugs for treating pain, particularly pain resistant to conventional analgesics. Emphasis will be on the old-new drugs, ketamine and magnesium, and their combination as a novel approach for treating chronic pain.

METHODS

The MEDLINE database was searched via PubMed for articles that were published up to March 1, 2020, with the keywords 'ketamine', 'magnesium', and 'pain' (in the title/abstract).

RESULTS

Studies in animals, as well as humans, have shown that interactions of ketamine and magnesium can be additive, antagonistic, and synergistic. These discrepancies might be due to differences in magnesium and ketamine dosage, administration times, and the chronological order of drug administration. Different kinds of pain can also be the source of divergent results.

CONCLUSION

This review explains why studies performed with a combination of ketamine and magnesium have given inconsistent results. Because of the lack of efficacy of drugs available for pain, ketamine and magnesium in combination provide a novel therapeutic approach that needs to be standardized with a suitable dosing regimen, including the chronological order of drug administration.

Comparison of Nebulized Ketamine at Three Different Dosing Regimens for Treating Painful Conditions in the Emergency Department: A Prospective, Randomized, Double-Blind Clinical Trial

STUDY OBJECTIVE

We aimed to assess and compare the analgesic efficacies and adverse effects of ketamine administered through a breath-actuated nebulizer at 3 different dosing regimens for emergency department patients presenting with acute and chronic painful conditions.

METHODS

This was a prospective, randomized, double-blinded trial comparing 3 doses of nebulized ketamine (0.75 mg/kg, 1 mg/kg, and 1.5 mg/kg) administered through breath-actuated nebulizer in adult emergency department patients aged 18 years and older with moderate to severe acute and chronic pain. The primary outcome included the difference in pain scores on an 11-point numeric rating scale between all 3 groups at 30 minutes. Secondary outcomes included the need for rescue analgesia (additional doses of nebulized ketamine or intravenous morphine) and adverse events in each group at 30 and 60 minutes.

RESULTS

We enrolled 120 subjects (40 per group). The difference in mean pain scores at 30 minutes between the 0.75 mg/kg and 1 mg/kg groups was 0.25 (95% confidence interval [CI] 1.28 to 1.78); between the 1 mg/kg and 1.5 mg/kg groups was -0.225 (95% CI -1.76 to 1.31); and between the 0.75 mg/kg and 1.5 mg/kg groups was 0.025 (95% CI -1.51 to 1.56). No clinically concerning changes in vital signs occurred. No serious adverse events occurred in any of the groups.

CONCLUSION

We found no difference between all 3 doses of ketamine administered through breath-actuated nebulizer for short-term treatment of moderate to severe pain in the emergency department.

A randomized, noninferiority, controlled trial of two doses of intravenous subdissociative ketamine for analgesia in the emergency department

OBJECTIVE

This study aimed to determine if 0.15 mg/kg intravenous (IV) subdissociative ketamine is noninferior to 0.3 mg/kg in emergency department (ED) patients with acute pain.

METHODS

This randomized, prospective, double-blinded, noninferiority trial included patients' age 18 to 59 years presenting to the ED with acute moderate to severe pain. Subjects were randomized to IV subdissociative ketamine, 0.15 mg/kg ("low" dose) or 0.30 mg/kg ("high" dose), over 15 minutes. The primary endpoint was the 11-point numeric rating scale (NRS) pain score between groups at 30 minutes. Secondary endpoints included NRS pain scores at 15 and 60 minutes; change in NRS at 15, 30, and 60 minutes; rescue analgesia; and adverse effects. The noninferiority limit, δ₀ , was set to 1.3.

RESULTS

Forty-nine patients were included in each group. After the differences in the baseline NRS score were adjusted for, the mean NRS score at 30 minutes was 4.7 (95% confidence interval [CI] = 3.8 to 5.5) in the low-dose group and 5.0 (95% CI = 4.2 to 5.8) in the high-dose group (mean difference = 0.4, 95% CI = -0.8 to 1.5), indicating that the low-dose subdissociative ketamine was noninferior to the high dose (lower limit of 95% CI = -0.8 to ≥1.3 = -δ₀ ). Adverse effects were similar at 30 minutes. At 15 minutes, the high-dose group experienced greater change in NRS; however, more adverse effects occurred.

CONCLUSION

Our data did not detect a large difference in analgesia or adverse effect profile between 0.15 mg/kg IV ketamine and 0.30 mg/kg in the short-term treatment of acute pain in the ED.

The Reemergence of Ketamine for Treatment in Critically Ill Adults

OBJECTIVES

To assess the evidence and discuss the risks and clinical relevance of ketamine for the treatment of various disease states impacting the adult critically ill population.

DATA SOURCES

A literature review was performed using PubMed evaluating primary literature published until August 2018.

STUDY SELECTION

Case reports, observational studies (cohort, case-control), and randomized controlled trials involving patients 18 years and older in a nonperioperative setting using either IV or intramuscular ketamine were included for analysis. Uses of ketamine discussed focused on critically ill patients in the ICU and emergency department settings.

DATA EXTRACTION

Included studies were evaluated for dosing, outcomes, and adverse effects of ketamine. For each study, the design, population, intervention, investigated outcomes, and results were assessed.

DATA SYNTHESIS

The evidence was organized according to use of ketamine, which included pain, sedation, status asthmaticus, alcohol withdrawal syndrome, status epilepticus, and acute behavioral psychologic disturbances. Evaluation of the evidence was based on the included primary literature along with any related guideline recommendations.

CONCLUSIONS

Ketamine has suggested potential benefit in several disease states impacting critically ill patients including pain, alcohol withdrawal syndrome, status epilepticus, and acute agitation. Further supporting evidence is needed to validate its use in the setting of critical illness.

Low-dose Ketamine For Acute Pain Control in the Emergency Department: A Systematic Review and Meta-analysis

OBJECTIVE

There has been increased interest in the use of low-dose ketamine (LDK) as an alternative analgesic for the management of acute pain in the emergency department (ED). The objective of this systematic review was to compare the analgesic effectiveness and safety profile of LDK and morphine for acute pain management in the ED.

METHODS

Electronic searches of Medline and EMBASE were conducted and reference lists were hand-searched. Randomized controlled trials (RCTs) comparing LDK to morphine for acute pain control in the ED were included. Two reviewers independently screened abstracts, assessed quality of the studies, and extracted data. Data were pooled using random-effects models and reported as mean differences and risk ratios (RRs) with 95% confidence intervals (CIs). We used the Grading of Recommendations Assessment, Development and Evaluation approach to assess the certainty of the evidence.

RESULTS

Eight RCTs were included with a total of 1,191 patients (LDK = 598, morphine = 593). There was no significant difference in reported mean pain scores between LDK and morphine within the first 60 minutes after analgesia administration and a slight difference in pain scores favoring morphine at 60 to 120 minutes. The need for rescue medication was also similar between groups (RR = 1.26, 95% CI = 0.50 to 3.16), as was the proportion of patients who experienced nausea (RR = 0.97, 95% CI = 0.63 to 1.49) and hypoxia (RR = 0.38, 95% CI = 0.10 to 1.41). All outcomes were judged to have low certainty in the evidence.

CONCLUSION

Low-dose ketamine and morphine had similar analgesic effectiveness within 60 minutes of administration with comparable safety profiles, suggesting that LDK is an effective alternative analgesic for acute pain control in the ED.

Optimizing Pain Control and Minimizing Opioid Use in Trauma Patients

Adverse effects of opioids and the ongoing crisis of opioid abuse have prompted providers to reduce prescribing opioids and increase use of multiple nonpharmacologic therapies, nonopioid analgesics, and co-analgesics for pain management in trauma patients. Nonopioid agents, including acetaminophen, nonsteroidal anti-inflammatory drugs, gabapentinoids, ketamine, central α2 agonists, and lidocaine, can be used as adjuncts or alternatives to opioids in the trauma population. Complementary therapies such as acupuncture, virtual reality, and mirror therapy are modalities that also may be helpful in reducing pain. Performing pain assessments is fundamental to identify pain and evaluate treatment effectiveness in the critically ill trauma patient. The efficacy, safety, and availability of opioid-sparing therapies and multimodal pain regimens are reviewed.

[Analgesia for trauma patients in emergency medicine]

Adequate analgesia is one of the most important measures of emergency care in addition to treatment of vital function disorders and, if indicated, should be promptly undertaken; however, a large proportion of emergency patients receive no or only inadequate pain therapy. The numeric rating scale (NRS) is recommended for pain assessment but is not applicable to every group of patients; therefore, vital signs and body language should be included in the assessment. Pain therapy should reduce the NPRS to <5 points. Ketamine and fentanyl, which have an especially rapid onset of action, and also morphine are suitable for analgesia in spontaneously breathing patients. Basic prerequisites for safe and effective analgesia by healthcare professionals are the use of adequate monitoring, the provision of well-defined emergency equipment, and the mastery of emergency procedures. In a structured competence system, paramedics and nursing personnel can perform safe and effective analgesia.

Ketamine Versus Etomidate and Peri-intubation Hypotension: A National Emergency Airway Registry Study

BACKGROUND

The hemodynamic impact of induction agents is a critically important consideration in emergency intubations. We assessed the relationship between peri-intubation hypotension and the use of ketamine versus etomidate as an induction agent for emergency department (ED) intubation.

METHODS

We analyzed ED intubation data for patients aged >14 years from the National Emergency Airway Registry performed in 25 EDs during 2016 through 2018. We excluded patients with preintubation hypotension (systolic blood pressure <100 mm Hg) or cardiac arrest prior to intubation. The primary outcome was peri-intubation hypotension. Secondary outcomes included interventions for hypotension (e.g., intravenous fluids or vasopressors). We report adjusted odds ratios (aOR) from multivariable logistic regression models controlling for patient demographics, difficult airway characteristics, and intubation modality.

RESULTS

There were 738 encounters with ketamine and 6,068 with etomidate. Patients receiving ketamine were more likely to have difficult airway characteristics (effect size difference = 8.8%, 95% confidence interval [CI] = 5.3% to 12.4%) and to undergo intubation with video laryngoscopy (8.1%, 95% CI = 4.4% to 12.0%). Peri-intubation hypotension incidence was 18.3% among patients receiving ketamine and 12.4% among patients receiving etomidate (effect size difference = 5.9%, 95% CI = 2.9% to 8.8%). Patients receiving ketamine were more likely to receive treatment for peri-intubation hypotension (effect size difference = 6.5%, 95% CI = 3.9% to 9.3%). In logistic regression analyses, patients receiving ketamine remained at higher risk for peri-intubation hypotension (aOR = 1.4, 95% CI = 1.2 to 1.7) and treatment for hypotension (aOR = 1.8, 95% CI = 1.4 to 2.0). There was no difference in the aOR of hypotension between patients receiving ketamine at doses ≤1.0 mg/kg versus >1.0 mg/kg or patients receiving etomidate at doses ≤0.3 mg/kg versus >0.3 mg/kg.

CONCLUSIONS

Pending additional data, our results suggest that clinicians should not necessarily prioritize ketamine over etomidate based on concern for hemodynamic compromise among ED patients undergoing intubation.

Intranasal Ketamine as an Adjunct to Fentanyl for the Prehospital Treatment of Acute Traumatic Pain: Design and Rationale of a Randomized Controlled Trial

Objective: Acute pain management is fundamental in prehospital trauma care. Early pain control may decrease the risk of developing post-traumatic stress disorder (PTSD) and chronic pain. Fentanyl and ketamine are frequently used off-label, but there is a paucity of comparative data to guide decision-making about treatment of prehospital severe, acute pain. This trial will determine whether the addition of single dose of intranasal ketamine to fentanyl is more effective for the treatment of acute traumatic pain than administration of fentanyl alone.Methods: This two-part study consists of prehospital and 90-day follow-up components (NCT02866071). The prehospital trial is a blinded, randomized, controlled trial of adult men (age 18-65 years) rating pain ≥7/10 after an acute traumatic injury of any type. Women will be excluded due to inability to confirm pregnancy status and unknown fetal risk. Paramedics will screen patients receiving standard of care fentanyl and, after obtaining standard informed consent, administer 50 mg intranasal ketamine or matching volume saline as placebo. Upon emergency department (ED) arrival, research associates will serially assess pain, concomitant treatments, and adverse side effects. Enrolled subjects will be approached for consent to participate in the 90-day follow-up study to determine rates of PTSD and chronic pain development. The primary outcome of the prehospital study is reduction in pain on the Verbal Numerical Rating Scale between baseline and 30-minutes after study drug administration. The proportion achieving a reduction of ≥2-points will be compared between study arms using a Chi-square test. Secondary outcomes of the prehospital trial include reduction in reported pain at the time of ED arrival and at 30 minutes intervals for up to three hours of ED care, the incidence of adverse events, and additional opiate requirements prior to ED arrival and within the first three hours of ED care. The outcomes in the follow-up study are satisfaction with life and development of PTSD or chronic pain at 90 days after injury. An intention-to-treat approach will be used.Conclusion: These studies will test the hypotheses that ketamine plus fentanyl, when compared to fentanyl alone, effectively manages pain, decreases opiate requirements, and decreases PTSD at 90 days.

Approaching acute pain in emergency settings; European Society for Emergency Medicine (EUSEM) guidelines-part 2: management and recommendations

BACKGROUND

In Europe, healthcare systems and education, as well as the clinical care and health outcomes of patients, varies across countries. Likewise, the management of acute events for patients also differs, dependent on the emergency care setting, e.g. pre-hospital or emergency department. There are various barriers to adequate pain management and factors common to both settings including lack of knowledge and training, reluctance to give opioids, and concerns about drug-seeking behaviour or abuse. There is no single current standard of care for the treatment of pain in an emergency, with management based on severity of pain, injury and local protocols. Changing practices, attitudes and behaviour can be difficult, and improvements and interventions should be developed with barriers to pain management and the needs of the individual emergency setting in mind.

METHODS

With these principles at the forefront, The European Society for Emergency Medicine (EUSEM) launched a programme-the European Pain Initiative (EPI)-with the aim of providing information, advice, and guidance on acute pain management in emergency settings.

RESULTS AND CONCLUSIONS

This article provides treatment recommendations from recently developed guidelines, based on a review of the literature, current practice across Europe and the clinical expertise of the EPI advisors. The recommendations have been developed, evaluated, and refined for both adults and children (aged ≥ 1 year, ≤ 15 years), with the assumption of timely pain assessment and reassessment and the possibility to implement analgesia. To provide flexibility for use across Europe, options are provided for selection of appropriate pharmacological treatment.

Transient amnesia following prehospital low-dose ketamine administration

Low doses of ketamine have been shown to be safe and effective for pain relief. Adverse effects are generally mild and transient. A 69-year-old woman suffered a witnessed ground-level fall without report of head injury, loss of consciousness, or intoxication. She was in severe pain despite 10 mg of intravenous morphine and paramedics provided intravenous ketamine 16 mg (0.19 mg/kg). Upon arrival to the ED, she was alert and oriented. An X-ray demonstrated an acute comminuted nondisplaced right humeral head and neck fracture. Her pain improved after an additional 4 mg of morphine and placement of a sling. Prior to discharge, the patient developed confusion, difficulty finding words, amnesia to the event, and anterograde amnesia evidenced by repetitive questioning. A head CT and a CT angiogram of the patient's head and neck demonstrated no acute abnormalities and an EEG demonstrated no epileptiform activity. The patient was admitted for observation and her mental status gradually improved overnight. She was discharged the following morning. Low dose ketamine is an important therapeutic option. Delayed or prolonged neuropsychiatric effects may be possible following combined ketamine and opioid analgesia. Clinicians utilizing low dose ketamine should be aware of this potential complication as it could result in the need for additional diagnostic testing and prolonged length of stay.

Ketamine as a Prehospital Analgesic: A Systematic Review

OBJECTIVE

Analgesia in the prehospital setting is an extremely important, yet controversial topic. Ketamine, a N-methyl D-aspartate (NMDA) receptor antagonist, has been commonly used in the prehospital setting, including recommendations by the US Department of Defense and by the Royal Australian College of Pain Medicine, despite the paucity of high-level evidence.

METHODS

Accordingly, a review of the literature was conducted using several electronic medical literature databases from the earliest available records to the time at which the search was conducted (October 2018).

RESULTS

The search strategy yielded a total of 707 unique papers, of which 43 were short-listed for full review, and ultimately, ten papers were identified as meeting all the relevant inclusion criteria. The included studies varied significantly in the prehospital context and in the means of administering ketamine. There was only low-grade evidence that ketamine offered a safe and effective analgesia when used as the only analgesic, and only low-grade evidence that it was as effective as alternative opioid options. However, there was moderate evidence that co-administration of ketamine with morphine may improve analgesic efficacy and reduce morphine requirement.

CONCLUSIONS

Overall, ketamine as a prehospital analgesic may be best used in combination with opioids to reduce opioid requirement. It is suggested that future studies should use a standardized approach to measuring pain reduction. Future studies should also investigate short-term side effects and long-term complications or benefits of prehospital ketamine.

Prehospital Use of Ketamine in the Combat Setting: A Sub-Analysis of Patients With Head Injuries Evaluated in the Prospective Life Saving Intervention Study

Objectives

Ketamine is used as an analgesic for combat injuries. Ketamine may worsen brain injury, but new studies suggest neuroprotection. Our objective was to report the outcomes of combat casualties with traumatic brain injury (TBI) who received prehospital ketamine.

Methods

This was a post hoc, sub-analysis of a larger prospective, multicenter study (the Life Saving Intervention study [LSI]) evaluating prehospital interventions performed in Afghanistan. A DoD Trauma Registry query provided disposition at discharge and outcomes to be linked with the LSI data.

Results

For this study, we enrolled casualties that were suspected to have TBI (n = 160). Most were 26-year-old males (98%) with explosion-related injuries (66%), a median injury severity score of 12, and 5% mortality. Fifty-seven percent (n = 91) received an analgesic, 29% (n = 46) ketamine, 28% (n = 45) other analgesic (OA), and 43% (n = 69) no analgesic (NA). The ketamine group had more pelvic injuries (P = 0.0302) and tourniquets (P = 0.0041) compared to OA. In comparison to NA, the ketamine group was more severely injured and more likely to require LSI procedures, yet, had similar vital signs at admission and disposition at discharge.

Conclusions

We found that combat casualties with suspected TBI that received prehospital ketamine had similar outcomes to those that received OAs or NAs despite injury differences.

Comparative Effectiveness of Analgesics to Reduce Acute Pain in the Prehospital Setting

Objectives: The objectives of this study were to assess comparative effectiveness and harms of opioid and nonopioid analgesics for the treatment of moderate to severe acute pain in the prehospital setting. Methods: We searched MEDLINE^®, Embase^®, and Cochrane Central from the earliest date through May 9, 2019. Two investigators screened abstracts, reviewed full-text files, abstracted data, and assessed study level risk of bias. We performed meta-analyses when appropriate. Conclusions were made with consideration of established clinically important differences and we graded each conclusion's strength of evidence (SOE). Results: We included 52 randomized controlled trials and 13 observational studies. Due to the absence or insufficiency of prehospital evidence we based conclusions for initial analgesia on indirect evidence from the emergency department setting. As initial analgesics, there is no evidence of a clinically important difference in the change of pain scores with opioids vs. ketamine administered primarily intravenously (IV) (low SOE), IV acetaminophen (APAP) (low SOE), or nonsteroidal anti-inflammatory drugs (NSAIDs) administered primarily IV (moderate SOE). The combined use of an opioid and ketamine, administered primarily IV, may reduce pain more than an opioid alone at 15 and 30 minutes (low SOE). Opioids may cause fewer adverse events than ketamine (low SOE) when primarily administered intranasally. Opioids cause less dizziness than ketamine (low SOE) but may increase the risk of respiratory depression compared with ketamine (low SOE), primarily administered IV. Opioids cause more dizziness (moderate SOE) and may cause more adverse events than APAP (low SOE), both administered IV, but there is no evidence of a clinically important difference in hypotension (low SOE). Opioids may cause more adverse events and more drowsiness than NSAIDs (low SOE), both administered primarily IV. Conclusions: As initial analgesia, opioids are no different than ketamine, APAP, and NSAIDs in reducing acute pain in the prehospital setting. Opioids may cause fewer total side effects than ketamine, but more than APAP or NSAIDs. Combining an opioid and ketamine may reduce acute pain more than an opioid alone but comparative harms are uncertain. When initial morphine is inadequate, giving ketamine may provide greater and quicker acute pain relief than giving additional morphine, although comparative harms are uncertain. Due to indirectness, strength of evidence is generally low, and future research in the prehospital setting is needed.

Lornoxicam with Low-Dose Ketamine versus Pethidine to Control Pain of Acute Renal Colic

Objectives

This study was established to compare single-dose lornoxicam 8 mg (NSAID) in addition to 0.15 mg.kg⁻¹ ketamine with single-dose pethidine 50 mg, both administered intravenously (IV), on the quickness and extent of analgesia, disadvantage, and consequence on utilitarian situation.

Patients and Methods

One hundred and twenty patients with acute renal colic pain received in emergency room were included in this prospective, randomized, and double blind clinical study. They were aimlessly designated into one of two groups using a computer-generated table. Group L received lornoxicam 8 mg IV plus 0.15 mg.kg⁻¹ ketamine and Group P received pethidine 50 mg IV. Parameters were noticed at baseline and after 0, 15, 30, and 45 minutes and 1 hour after drug administration. The efficiency of the drug was determined by observing: patient rated pain, time to pain relief, rate of pain recurrence, the need for rescue analgesia, adverse events, and functional status.

Results

The visual analogue scale was significantly lower in Group L after 30 minutes in comparison to Group P. In addition, there was statistically significant increase in Group P regarding their need for rescue analgesia after 30 min in comparison to Group L. Group P showed nonsignificantly increased sedation score compared to Group L.

Conclusion

Patients receiving lornoxicam-ketamine attained greater reduction in pain scores and less side effects with better functional state and also are less likely to require further analgesia than those administered pethidine to control acute renal colic pain.