Comparison of intranasal ketamine versus IV morphine in reducing pain in patients with renal colic

Exploring the Efficacy and Safety of Ketamine for Managing Acute Renal Colic in Emergency Departments: A Systematic Review of Recent Clinical Trials

Kidney stones typically present as renal colic in emergency departments (EDs), where patients experience severe pain and often require parenteral therapy for symptom management. The economic burden associated with managing kidney stones exceeds USD 5 billion annually in the US and accounts for more than a million visits to EDs each year. There is clear evidence emphasizing the need for innovative and alternative pain control options for patients with renal colic. Recent randomized controlled trials suggest that intranasal (IN) and intravenous (IV) ketamine are as effective as parenteral NSAIDs and opioids in treating renal colic. However, the limited studies available show inconsistent results regarding the analgesic effects of ketamine. In this study, we reviewed the mechanism of action of ketamine for kidney stones, its efficacy in treating acute renal colic, and the potential adverse side effects of ketamine treatment. A population, intervention, comparison, and outcome (PICO)-related question was formulated to guide our research inquiry: "What are the effects of IV or IN ketamine, as a single agent or as an adjuvant (I), in adult patients diagnosed with acute renal colic (P) on pain scale scores and adverse side effects (O) compared to NSAIDs and/or opioids (C)?"

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.

2022 Recommendations of the AFU Lithiasis Committee: Management of symptomatic urinary stones

The acute situation, caused by an obstructive stone, is defined by a renal colic that may be uncomplicated, complicated, or at risk in specific conditions. Its management may be medical or require interventional treatment by extracorporeal shockwave lithotripsy, endoscopic removal, or ureteroscopy. METHODOLOGY: These recommendations were developed using two methods, the Clinical Practice Recommendations (CPR) and the ADAPTE method, in function of whether the question was considered in the European Association of Urology (EAU) recommendations (https://uroweb.org/guidelines/urolithiasis) [EAU Guidelines on urolithiasis. 2022] and whether they could be adapted to the French context.

Effectiveness of Intranasal Analgesia in the Emergency Department

In the Emergency Department (ED), pain is one of the symptoms that are most frequently reported, making it one of the most significant issues for the emergency physician, but it is frequently under-treated. Intravenous (IV), oral (PO), and intramuscular (IM) delivery are the standard methods for administering acute pain relief. Firstly, we compared the safety and efficacy of IN analgesia to other conventional routes of analgesia to assess if IN analgesia may be an alternative for the management of acute pain in ED. Secondly, we analyzed the incidence and severity of adverse events (AEs) and rescue analgesia required. We performed a narrative review-based keywords in Pubmed/Medline, Scopus, EMBASE, the Cochrane Library, and Controlled Trials Register, finding only twenty randomized Clinical trials eligible in the timeline 1992-2022. A total of 2098 patients were analyzed and compared to intravenous analgesia, showing no statistical difference in adverse effects. In addition, intranasal analgesia also has a rapid onset and quick absorption. Fentanyl and ketamine are two intranasal drugs that appear promising and may be taken simply and safely while providing effective pain relief. Intravenous is simple to administer, non-invasive, rapid onset, and quick absorption; it might be a viable choice in a variety of situations to reduce patient suffering or delays in pain management.

Efficacy and Safety of Ketamine Versus Opiates in the Treatment of Patients with Renal Colic: A Systematic Review and Meta-analysis

INTRODUCTION

Renal colic is one of the most common urological emergencies, and is usually caused by ureteral colic spasms. Pain management in renal colic remains the central focus of emergency treatment. The purpose of this meta-analysis is to identify the efficacy and safety of ketamine versus opioids in the treatment of patients with renal colic.

METHODS

We searched PubMed, EMBASE, Cochrane Library, and Web of Science databases for published randomized controlled trials (RCTs) that referred to the use of ketamine and opioids for patients with renal colic. The methodology was based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The mean difference (MD) or odds ratio (OR) with a 95% confidence interval (CI) was used to analyze the data. The results were pooled using a fixed-effects model or random-effects model. The primary outcome measure was patient-reported pain scores 5, 15, 30, and 60 min after drug administration. The secondary outcome measure was side effects.

RESULTS

The data analysis revealed that ketamine was similar to opioids in pain intensity at the time of 5 min post-dose (MD = - 0.40, 95% CI - 1.82 to 1.01, P = 0.57), 15 min post-dose (MD = - 0.15, 95% CI - 0.82 to 0.52, P = 0.67), 30 min post-dose (MD = 0.38, 95% CI - 0.25 to 1.01, P = 0.24). Also, the pain score of ketamine was better than that of opioids at 60 min after administration (MD = - 0.12, 95% CI - 0.22 to - 0.02, P = 0.02). As for safety, the ketamine group was linked to a significant decrease in the incidence of hypotensive (OR = 0.08, 95% CI 0.01-0.65, P = 0.02). The two groups did not statistically differ in the incidence of nausea, vomiting, and dizziness.

CONCLUSIONS

Compared with opioids, ketamine showed a longer duration of analgesia in renal colic, with satisfactory safety.

TRIAL REGISTRATION

The PROSPERO registration number is CRD42022355246.

Effects of adding oral clonidine to standard treatments on pain intensity of patients with acute renal colic: A randomized clinical trial

Background:

The aim of this study was to compare the effect of adding oral clonidine to standard treatments on pain intensity in patients with acute renal colic.

Materials and Methods:

This is a randomized clinical trial that was performed in 2020 in Isfahan. The study population consisted of 200 patients with renal colic. Pain of the patients was assessed using Visual Analog Scale. Patients were then randomized into 4 groups of 50 patients. Group A received 0.1 mg/kg morphine and clonidine tablets (0.2 mg). Group B received morphine and placebo. Group C received 30 mg ketorolac and clonidine tablets. Group D received 30 mg ketorolac and placebo tablets. Pain of patients was assessed. 0.05 mg/kg morphine was administered and repeated every 40 min if the pain was not reduced.

Results:

Our data showed that there was a significant difference between pains of patient by the time of admission in groups (P = 0.04). However, no significant differences were observed between pains of patients in different measuring times (P > 0.05). Using general linear model, we showed that the decreases in pain scores of each group were significant (P < 0.05) but there were no significant differences in pains of patients in different measuring times (P > 0.05). Our data showed that Group A and Group C had lowest frequencies of morphine administrations while Groups B and D had the highest frequencies (P < 0.001).

Conclusion:

We showed that administration of clonidine in patients with renal colic resulted in better pain control and lower morphine injections.

Efficacy and Safety of Intranasal Ketamine for Acute Pain Management in the Emergency Setting: A Systematic Review and Meta-Analysis

Due to overcrowding, personnel shortages, or problematic intravenous (IV) cannulation, acute pain management is often sub-optimal in emergency departments (EDs). The objective of this systematic review and meta-analysis was to evaluate the efficacy and safety of intranasal (IN) ketamine for adult acute pain in the emergency setting. We searched and identified studies up to 21 May 2021 via PubMed, Scopus, Web of Science, Cochrane Database, and Google Scholar. The random-effects model with 95% confidence intervals (CIs) was used to estimate mean differences (MDs) and odds ratios (ORs). The I² statistic and Cochran’s Q test were used to determine heterogeneity. The protocol was registered in PROSPERO (CRD42020213391). Seven randomised controlled trials were included with a total of 1760 patients. There was no significant difference in pain scores comparing IN ketamine with IV analgesics or placebo at 5 (MD 0.94, p = 0.26), 15 (MD 0.15, p = 0.74), 25 (MD 0.24, p = 0.62), 30 (MD −0.05, p = 0.87), and 60 (MD −0.42, p = 0.53) minutes. There was also no significant difference in the need for rescue analgesics between IN ketamine and IV analgesics (OR 1.66, 95% CI: 0.57−4.86, p = 0.35, I² = 70%). Only mild adverse effects were observed in patients who received IN ketamine. Our results suggest that IN ketamine is non-inferior to IV analgesics and may have a role in acute pain management among adults in the ED.

Effect on Opioids Requirement of Early Administration of Intranasal Ketamine for Acute Traumatic Pain

OBJECTIVES

To evaluate the efficacy and safety of early administration of low-dose intranasal ketamine on reducing the need for opioid and nonopioid analgesic agents in emergency department (ED) patients with acute moderate to severe acute limbs' trauma pain.

PATIENTS AND METHODS

This is a double-blind, randomized, prospective, controlled study conducted in the ED. The included patients were randomly assigned to intranasal pulverization of ketamine or placebo. Protocol treatment was given at the triage. The primary outcome is the need for opioids during ED stay. Secondary outcome included the requirement of nonopioid analgesic agents and the percentage of patients discharged from the ED with a visual analog scale (VAS) <30. A combined outcome score including the 3 outcome items was constructed.

RESULTS

The authors included 1102 patients, 550 patients in the placebo group, and 552 in the intranasal ketamine group. The groups were similar regarding demographics, clinical characteristics, and baseline VAS. The need for opioids was decreased in the intranasal ketamine group compared with the placebo group (17.2% vs. 26.5%; P<0.001). The need for nonopioid analgesics was significantly lower in the intranasal ketamine group compared with the placebo group (31.1% vs. 39.6%; P=0.003). The percentage of patients discharged with a VAS score <30 was significantly higher in the intranasal ketamine group (P<0.001). The mean combined outcome score was 0.97 in the placebo group and 0.67 in the intranasal ketamine group (P<0.001).

CONCLUSION

Intranasal ketamine administered early in the triage was associated with a decrease in opioids and nonopioid analgesics need in patients with acute limb trauma-related pain.

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.

Intranasal Ketamine for Acute Pain

OBJECTIVES

The aim was to review current evidence regarding the off-label use of intranasal ketamine for acute pain presenting in the setting of the emergency department, and secondary to pediatric limb injuries, renal colic, digital nerve block, and migraines.

RESULTS

In all 5 indications reviewed, ketamine demonstrated efficacy in reducing pain. However, when compared with other agents, ketamine did not demonstrate superiority over opioids in pediatric limb injuries or renal colic and was not as efficacious as standard therapy for migraine relief. Ketamine was also associated with a greater incidence of transient adverse reactions, such as dizziness, bitter aftertaste, fatigue, and vomiting than opioid therapies.

DISCUSSION

The current body of evidence is insufficient to support the use of intranasal ketamine over other standard therapies for acute pain. However, current evidence can be used when developing dosing strategies, preparing for adverse reactions, and generating hypotheses for future, more robust research.

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.

Intranasal ketamine versus intravenous morphine for pain management in patients with renal colic: a double-blind, randomized, controlled trial

BACKGROUND

Urinary stones are a common urologic problem that can be manifested as an intense pain, known as renal colic. Pain control is an important intervention for the emergency treatment of renal colic patients. Intranasal ketamine can form a crucial part of such interventions by offering a new route for a widely-used analgesic drug.

METHODS

In a double-blind, randomized, clinical trial, adults with renal colic admitted to a tertiary hospital emergency department were examined. The intervention group received 1 mg/kg intranasal (IN) ketamine and 1 ml of saline as a placebo. The control group received 0.1 mg/kg intravenous (IV) morphine and four puffs of saline as the placebo. The pain score was measured on the Numerical Rating Scale (NRS) 0, 15, 30 and 60 min after the drug administration.

RESULTS

A total of 184 patients enrolled in this study in two parallel groups. The two groups did not differ significantly in terms of pain intensity at the time of their referral (P = 0.489), 15 min post-dose (P = 0.204), 30 min post-dose (P = 0.978) and 60 min post-dose (P = 0.648).

CONCLUSION

IN ketamine is as effective as IV morphine for pain control in renal colic patients. No remarkable side-effects were observed for IN ketamine use in these patients.

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.

Comparison of the Analgesic Effect of Intravenous Ketamine versus Intravenous Morphine in Reducing Pain of Renal Colic Patients: Double-Blind Clinical Trial Study

BACKGROUND

The effective relief of renal colic patients with low complications is one of the important concerns of emergency physicians. The aim of this study was to investigate the use of injectable ketamine as an alternative to routine drugs in the relief of pain in patients with renal colic.

METHODS

This double-blind clinical trial was conducted on patients who had suffered kidney pain due to kidney stones in 2017, referred to Ahvaz Imam Khomeini Hospital. Patients were divided into 2 groups: the first group received intravenous ketamine (0.3 mg/kg) and the second group received intravenous morphine (0.1 mg/kg) in a double-blind form. Finally, the mean pain was evaluated before injection, after 10, 20, 30, and 60 minutes as the initial result while the side effects were considered as secondary results.

RESULTS

In this study, 135 patients with renal colic participate in this study. The mean pain at the time of referral to the hospital in the group receiving morphine and ketamine was 9.2 and 9.2, respectively, which did not show any significant difference. Based on these findings, there was no significant difference between the factors evaluated during the study of the two groups. Only in the ketamine group, there were 3 cases of nausea and 1 of vomiting. However, there was a significant increase in the need for additional doses of fentanyl in the morphine recipient group (p = 0.02).

CONCLUSION

The findings suggest that the use of ketamine can produce a more rapid relief effect, and decrease the use of opioids which create various complications, including nausea and vomiting in patients, especially patients with renal colic.

Low-dose intravenous ketamine versus intravenous ketorolac in pain control in patients with acute renal colic in an emergency setting: a double-blind randomized clinical trial

BACKGROUND

This study was conducted to compare the effectiveness of low-dose ketamine versus ketorolac in pain control in patients with acute renal colic presenting to the emergency department (ED).

METHODS

This is a double-blind randomized clinical trial. The initial pain severity was assessed using the numerical rating scale (NRS). Then, ketamine or ketorolac was administered intravenously at a dose of 0.6 mg/kg and 30 mg respectively. The pain severity and adverse drug reactions were recorded 5, 15, 30, 60, and 120 min thereafter.

RESULTS

The data of 62 subjects in the ketamine group and 64 patients in the ketorolac group were analyzed. The mean age of the patients was 34.2 ± 9.9 and 37.9 ± 10.6 years in the ketamine and ketorolac group, respectively. There was no significant difference in the mean NRS scores at each time point, except for the 5 min, between the two groups. Despite a marked decrease in pain severity in the ketamine group from drug administration at the 5 min, a slight increase in pain was observed from the 5 min to the 15 min. The rate of adverse drug reactions, including dizziness (P = 0.001), agitation (P = 0.002), increased systolic blood pressure (> 140 mmHg), and diastolic blood pressure (> 90 mmHg) was higher in the ketamine group.

CONCLUSIONS

Low dose ketamine is as effective as ketorolac in pain management in patients with renal colic presenting to the ED. However, it is associated with a higher rate of adverse drug reactions.

The Expanding Role of Ketamine in the Emergency Department

Patients frequently come to the emergency department for pain. For decades, ketamine has been used in the emergency department for procedural sedation but is now receiving attention as a potential alternative to opioids because of its unique analgesic effects. Additionally, ketamine's dissociative properties have made it a popular choice for sedating profoundly agitated patients. In this narrative review, these new roles for ketamine in the emergency department are discussed.

Effects of different doses of intranasal dexmedetomidine on preoperative sedation and postoperative agitation in pediatric with total intravenous anesthesia undergoing adenoidectomy with or without tonsillectomy

Dexmedetomidine is a highly selective α2 receptor agonist, this study aimed to investigate the effects of different doses of intranasal dexmedetomidine on the preoperative sedation and postoperative agitation in pediatric with total intravenous anesthesia (TIVA) for adenoidectomy with or without tonsillectomy.This is a double-blind placebo-controlled randomized trial. Pediatric were randomly divided into the D1, D2, and S groups, each group contained 30 patients. Twenty-five to 40 minutes before surgery, the D1 and D2 groups received intranasally dexmedetomidine 1 μg kg or 2 μg kg, respectively, while the S group received saline of the same volume. A unified protocol of TIVA induction and maintenance was used for the three groups. The preoperative sedation, behavior of separation from parents, postoperative agitation, and postoperative pain of the children were evaluated.The proportions of satisfactory sedation in the D1, D2, and S groups were 63.3%, 76.7%, and 0%, respectively. There was a statistically significant difference between D1 and S groups (P = .000) and D2 versus S groups (P = .000), while there was no statistically significant difference between D1 and D2 groups (P = .399). As for scale on the behavior of separation from parents, there was a statistically significant difference between D1 and S groups (P = .009) and D2 versus S groups (P = .009), whereas there was no significant difference between D1 and D2 groups (P = 1). The incidence of postoperative agitation in the D1, D2, and S groups was 43.3%, 30.0%, and 63.3%, respectively, and there was a statistical difference between D2 and S groups (P = .010). There was a significant difference in the Pediatric Anesthesia Emergence Delirium (PAED) scale between D2 and S groups (P = .029). The Children's Hospital of Eastern Ontario Pain Scale (CHEOPS) in the D2 group was significantly lower than the S group (P = .013).The intranasal dexmedetomidine of 1 or 2 μg kg 25 to 40 minute before induction of anesthesia both could deliver effective preoperative sedation, reducing the children's distress of separation from parents. Moreover, intranasal dexmedetomidine of 2 μg kg could deliver more effective postoperative analgesia and reduce postoperative agitation, without prolonging postoperative recovery or causing severe adverse events.

Consensus Guidelines on the Use of Intravenous Ketamine Infusions for Acute Pain Management From the American Society of Regional Anesthesia and Pain Medicine, the American Academy of Pain Medicine, and the American Society of Anesthesiologists

BACKGROUND

Ketamine infusions have been used for decades to treat acute pain, but a recent surge in usage has made the infusions a mainstay of treatment in emergency departments, in the perioperative period in individuals with refractory pain, and in opioid-tolerant patients. The widespread variability in patient selection, treatment parameters, and monitoring indicates a need for the creation of consensus guidelines.

METHODS

The development of acute pain ketamine guidelines grew as a corollary from the genesis of chronic pain ketamine guidelines. The charge for the development of acute pain ketamine guidelines was provided by the Boards of Directors of both the American Society of Regional Anesthesia and Pain Medicine and the American Academy of Pain Medicine, who approved the document along with the American Society of Anesthesiologists' Committees on Pain Medicine and Standards and Practice Parameters. The committee chair developed questions based on input from the committee during conference calls, which the committee then refined. Groups of 3 to 5 panel members and the committee chair were responsible for answering individual questions. After preliminary consensus was achieved, the entire committee made further revisions via e-mail and conference calls.

RESULTS

Consensus guidelines were prepared in the following areas: indications, contraindications for acute pain and whether they differ from those for chronic pain, the evidence for the use of ketamine as an adjunct to opioid-based therapy, the evidence supporting patient-controlled ketamine analgesia, the use of nonparenteral forms of ketamine, and the subanesthetic dosage range and whether the evidence supports those dosages for acute pain. The group was able to reach consensus on the answers to all questions.

CONCLUSIONS

Evidence supports the use of ketamine for acute pain in a variety of contexts, including as a stand-alone treatment, as an adjunct to opioids, and, to a lesser extent, as an intranasal formulation. Contraindications for acute pain are similar to those for chronic pain, partly based on the observation that the dosage ranges are similar. Larger studies evaluating different acute pain conditions are needed to enhance patient selection, determine the effectiveness of nonparenteral ketamine alternatives, define optimal treatment parameters, and develop protocols optimizing safety and access to care.

Intranasal Ketamine and Its Potential Role in Cancer-Related Pain

Cancer-related pain continues to be a significant therapeutic challenge, made more difficult by contemporary opioid use and diversion concerns. Conventional treatment using a tiered approach of nonsteroidal antiinflammatory drugs (NSAIDs), opioids, and adjuvant agents is limited; and alternatives are needed for patients with rapidly progressing pain and those who develop hyperalgesia and tolerance to opioids. Ketamine, an N-methyl-d-aspartate (NMDA) selective antagonist, has historically been used for anesthesia in adult and pediatric populations but has also been investigated for depression, bipolar disorder, and general and postoperative pain management. As an analgesic, low-dose ketamine decreases morphine requirements and rates of nausea and vomiting, suggesting a potentially beneficial role in cancer-related pain. Ketamine is typically administered intravenously and has a rapid onset of action with a relatively short half-life (2-3 hours) but is inconvenient for use in an ambulatory setting. Oral bioavailability is low and erratic, limiting application of this route for chronic use. Intranasal administration has a number of potential advantages, including avoidance of first-pass hepatic metabolism, no need for venous access, ability to repeat doses quickly, and rapid absorption. Although early studies of intranasal ketamine are promising in a number of indications, information is more limited in its use as an adjunct in cancer-related pain. We review the background, rationale, pharmacokinetics, and clinical and safety data using intranasal ketamine as an adjunctive agent and its potential in cancer-related pain.