Ketamine for continuous sedation of mechanically ventilated patients

Clinical Approach to Massive Hemoptysis: Perioperative Focus on Causes and Management

Massive hemoptysis is a time critical airway emergency in the perioperative setting, with an associated mortality exceeding 50%. Causes of hemoptysis in the perioperative setting include procedural complication, coagulopathy, malignancy, chronic lung disease, infection, left-sided cardiac disease, pulmonary vascular disease and autoimmune disease. A rapid and coordinated multidisciplinary response is required to secure the airway, isolate the lung, ensure adequate oxygenation and ventilation, identify the underlying cause and initiate specific systemic, bronchoscopic, endovascular, or surgical treatment. This review examines the etiology, pathophysiology, as well as approach to management and interventions in perioperative massive hemoptysis.

Efficacy of Continuous Infusion Ketamine for Analgosedation in the Medical Intensive Care Unit: A Propensity-Weighted Analysis

Background: Few randomized controlled trials have evaluated the use of ketamine vs opiate-based analgosedation. Methods: A retrospective cohort analysis of 169 mechanically ventilated patients admitted to the medical intensive care unit (MICU) at an academic medical center was conducted to evaluate efficacy of ketamine vs opiate-based analgosedation by comparing the percentage of time within target sedation range. The primary outcome was percentage of time within target sedation range (RASS -1 to +1) within first 72 hours of primary sedation initiation. Secondary outcomes including percentage of time under-sedated, over-sedated, and in coma; use of concomitant analgesic, sedative, and antipsychotic agents; presence of delirium; percentage of CPOT scores at goal; and hemodynamic effects were also evaluated. Results: After weighting, the mean percentage of time at RASS goal for ketamine patients was 43.0% compared to 41.4% for opiate-based sedation patients. Ketamine was not significantly non-inferior to opiate-based sedation for the mean percentage of time at RASS goal (P = .11). The median percentage of CPOT scores at goal was 13.3% higher in the ketamine group (P = .042). Patients in the ketamine group received significantly less additional sedative agents than the patients in the opiate-based sedation group. Conclusion: A similar percent of time at RASS goal was found for the ketamine analgosedation group compared to the opiate-based sedation group, although this did not reach statistical signicance for non-inferiority due to lack of statistical power. This study found a higher percentage of CPOT scores within goal with less additional sedative agents required compared to an opiate-based sedation regimen.

Exploring the Role of Ketamine Sedation in Critically Ill Patients: A Comprehensive Review

Sedation management in critically ill patients is a critical component of intensive care, aiming to balance the need for comfort and immobilization with preserving vital physiological functions. Ketamine, known for its dissociative anesthetic properties, has emerged as a promising alternative to traditional sedatives due to its unique pharmacological profile. This review explores the pharmacodynamics, clinical applications, benefits, challenges, and current evidence surrounding ketamine as a sedative agent in intensive care settings. Key advantages of ketamine include its ability to maintain respiratory drive and hemodynamic stability, making it particularly suitable for patients requiring continuous monitoring and intervention. The review discusses its role in sedation protocols, compares its effectiveness with other sedatives, and highlights potential areas for further research and optimization. By elucidating the complexities and advancements in ketamine sedation, this review aims to inform clinical practice and contribute to improved outcomes for critically ill patients.

Ketamine-based Sedation Use in Mechanically Ventilated Critically Ill Patients with COVID-19: A Multicenter Cohort Study

Backgrounds

Ketamine possesses analgesia, anti-inflammation, anticonvulsant, and neuroprotection properties. However, the evidence that supports its use in mechanically ventilated critically ill patients with COVID-19 is insufficient. The study's goal was to assess ketamine's effectiveness and safety in critically ill, mechanically ventilated (MV) patients with COVID-19.

Methods

Adult critically ill patients with COVID-19 were included in a multicenter retrospective-prospective cohort study. Patients admitted between March 1, 2020, and July 31, 2021, to five ICUs in Saudi Arabia were included. Eligible patients who required MV within 24 hours of ICU admission were divided into two sub-cohort groups based on their use of ketamine (Control vs. Ketamine). The primary outcome was the length of stay (LOS) in the hospital. P/F ratio differences, lactic acid normalization, MV duration, and mortality were considered secondary outcomes. Propensity score (PS) matching was used (1:2 ratio) based on the selected criteria.

Results

In total, 1,130 patients met the eligibility criteria. Among these, 1036 patients (91.7 %) were in the control group, whereas 94 patients (8.3 %) received ketamine. The total number of patients after PS matching, was 264 patients, including 88 patients (33.3 %) who received ketamine. The ketamine group's LOS was significantly lower (beta coefficient (95 % CI): -0.26 (-0.45, -0.07), P = 0.008). Furthermore, the PaO2/FiO2 ratio significantly improved 24 hours after the start of ketamine treatment compared to the pre-treatment period (6 hours) (124.9 (92.1, 184.5) vs. 106 (73.1, 129.3; P = 0.002). Additionally, the ketamine group had a substantially shorter mean time for lactic acid normalization (beta coefficient (95 % CI): -1.55 (-2.42, -0.69), P 0.01). However, there were no significant differences in the duration of MV or mortality.

Conclusions

Ketamine-based sedation was associated with lower hospital LOS and faster lactic acid normalization but no mortality benefits in critically ill patients with COVID-19. Thus, larger prospective studies are recommended to assess the safety and effectiveness of ketamine as a sedative in critically ill adult patients.

Ketamine in Critically Ill Patients: Use, Perceptions, and Potential Barriers

Objective: To evaluate practitioner use of ketamine and identify potential barriers to use in acutely and critically ill patients. To compare characteristics, beliefs, and practices of ketamine frequent users and non-users. Methods: An online survey developed by members of the Society of Critical Care Medicine (SCCM) Clinical Pharmacy and Pharmacology Section was distributed to physician, pharmacist, nurse practitioner, physician assistant and nurse members of SCCM. The online survey queried SCCM members on self-reported practices regarding ketamine use and potential barriers in acute and critically ill patients. Results: Respondents, 341 analyzed, were mostly adult physicians, practicing in the United States at academic medical centers. Clinicians were comfortable or very comfortable using ketamine to facilitate intubation (80.0%), for analgesia (77.9%), procedural sedation (79.4%), continuous ICU sedation (65.8%), dressing changes (62.4%), or for asthma exacerbation and status epilepticus (58.8% and 40.4%). Clinicians were least comfortable with ketamine use for alcohol withdrawal and opioid detoxification (24.7% and 23.2%). Most respondents reported "never" or "infrequently" using ketamine preferentially for continuous IV analgesia (55.6%) or sedation (61%). Responses were mixed across dosing ranges and duration. The most common barriers to ketamine use were adverse effects (42.6%), other practitioners not routinely using the medication (41.5%), lack of evidence (33.5%), lack of familiarity (33.1%), and hospital/institutional policy guiding the indication for use (32.3%). Conclusion: Although most critical care practitioners report feeling comfortable using ketamine, there are many inconsistencies in practice regarding dose, duration, and reasons to avoid or limit ketamine use. Further educational tools may be targeted at practitioners to improve appropriate ketamine use.

Continuous infusion ketamine for sedation of mechanically ventilated adults in the intensive care unit: A scoping review

Introduction

Mechanical ventilation (MV) is a common and often live-saving intervention on the Intensive Care Unit (ICU). The optimisation of sedation to mechanical ventilation is fundamental, and inappropriate sedation has been associated with worse outcomes. This scoping review has been designed to answer the question 'What is known about the use of ketamine as a continuous infusion to provide sedation in mechanically ventilated adults in the intensive care unit, and what are the gaps in the evidence?'

Methods

The protocol was designed using the PRISMA-ScR checklist and the JBI manual for evidence synthesis. Data were extracted and reviewed by a minimum of two reviewers.

Results

Searches of electronic databases (PubMed, OVID, Scopus, Web of Science) produced 726 results; 45 citations were identified for further eligibility assessment, an additional five studies were identified through keyword searches, and 12 through searching reference lists. Of these 62 studies, 27 studies were included in the final review: 6 case reports/case series, 11 retrospective cohort/observational studies, 1 prospective cohort study, 9 prospective randomised studies.

Conclusion

We found a lack of high-quality well-designed studies investigating the use of continuous ketamine sedation on ICU. The available data suggests this intervention is safe and well tolerated, however this is of very low certainty given the poor quality of evidence.

Ketamine: A Practical Review for the Consultation-Liaison Psychiatrist

BACKGROUND

Ketamine is a noncompetitive N-methyl-D-aspartate-receptor antagonist often used for sedation and management of acute agitation in general hospital settings. Many hospitals now include ketamine as part of their standard agitation protocol, and consultation-liaison psychiatrists frequently find themselves treating patients who have received ketamine, despite lack of clear recommendations for management.

OBJECTIVE

Conduct a nonsystematic narrative review regarding the use of ketamine for agitation and continuous sedation, including benefits and adverse psychiatric effects. Compare ketamine to more traditional agents of agitation control. Provide consultation-liaison psychiatrists with a summary of available knowledge and recommendations for managing patients receiving ketamine.

METHODS

A literature review was performed using PubMed, querying published articles from inception to March 2023 for articles related to use of ketamine for agitation or continuous sedation and side effects including psychosis and catatonia.

RESULTS

A total of 37 articles were included. Ketamine was found to have multiple benefits, including shorter time to adequate sedation for agitated patients when compared to haloperidol ± benzodiazepines and unique advantages for continuous sedation. However, ketamine carries significant medical risks including high rates of intubation. Ketamine appears to induce a syndrome that mimics schizophrenia in healthy controls, and such effects are more pronounced and longer-lasting in patients with schizophrenia. Evidence regarding rates of delirium with ketamine for continuous sedation is mixed and requires further investigation before the agent is widely adopted for this purpose. Finally, the diagnosis of "excited delirium syndrome" and use of ketamine to treat this controversial syndrome warrants critical evaluation.

CONCLUSIONS

Ketamine carries many potential benefits and can be an appropriate medication for patients with profound undifferentiated agitation. However, intubation rates remain high, and ketamine may worsen underlying psychotic disorders. It is essential that consultation-liaison psychiatrists understand the advantages, disadvantages, biased administration, and areas of limited knowledge regarding ketamine.

Targeting NMDA Receptor Complex in Management of Epilepsy

N-methyl-D-aspartate receptors (NMDARs) are widely distributed in the central nervous system (CNS) and play critical roles in neuronal excitability in the CNS. Both clinical and preclinical studies have revealed that the abnormal expression or function of these receptors can underlie the pathophysiology of seizure disorders and epilepsy. Accordingly, NMDAR modulators have been shown to exert anticonvulsive effects in various preclinical models of seizures, as well as in patients with epilepsy. In this review, we provide an update on the pathologic role of NMDARs in epilepsy and an overview of the NMDAR antagonists that have been evaluated as anticonvulsive agents in clinical studies, as well as in preclinical seizure models.

A Narrative Review of the Impact of Extracorporeal Membrane Oxygenation on the Pharmacokinetics and Pharmacodynamics of Critical Care Therapies

Objective:

Extracorporeal membrane oxygenation (ECMO) utilization is increasing on a global scale, and despite technological advances, minimal standardized approaches to pharmacotherapeutic management exist. This objective was to create a comprehensive review for medication dosing in ECMO based on the most current evidence.

Data Sources:

A literature search of PubMed was performed for all pertinent articles prior to 2022. The following search terms were utilized: ECMO, pharmacokinetics, pharmacodynamics, sedation, analgesia, antiepileptic, anticoagulation, antimicrobial, antifungal, nutrition. Retrospective cohort studies, case-control studies, case series, case reports, and ex vivo investigations were reviewed.

Study Selection and Data Extraction:

PubMed (1975 through July 2022) was the database used in the literature search. Non-English studies were excluded. Search terms included both drug class categories, specific drug names, ECMO, and pharmacokinetics.

Data Synthesis:

Medications with high protein binding (>70%) and high lipophilicity (logP > 2) are associated with circuit sequestration and the potential need for dose adjustment. Volume of distribution changes with ECMO may also impact dosing requirements of common critical care medications. Lighter sedation targets and analgosedation may help reduce sedative and analgesia requirements, whereas higher antiepileptic dosing is recommended. Vancomycin is minimally affected by the ECMO circuit and recommendations for dosing in critically ill adults are reasonable. Anticoagulation remains challenging as optimal aPTT goals have not been established.

Relevance to Patient Care and Clinical Practice:

This review describes the anticipated impacts of ECMO circuitry on sedatives, analgesics, anticoagulation, antiepileptics, antimicrobials, antifungals, and nutrition support and provides recommendations for drug therapy management.

Conclusions:

Medication pharmacokinetic/pharmacodynamic parameters should be considered when determining the potential impact of the ECMO circuit on attainment of therapeutic effect and target serum drug concentrations, and should guide therapy choices and/or dose adjustments when data are not available.

Advantages of ketamine in pediatric anesthesia

Although ketamine is primarily used for induction and maintenance of general anesthesia, it also presents sedative, amnestic, anesthetics, analgesic, antihyperalgesia, neuroprotective, anti-inflammatory, immunomodulant, and antidepressant effects. Its unique pharmacodynamics and pharmacokinetic properties allow the use of ketamine in various clinical settings including sedation, ambulatory anesthesia, and intensive care practices. It has also adopted to manage acute and chronic pain management. Clinically, ketamine produces dissociative sedation, analgesia, and amnesia while maintaining laryngeal reflexes, with respiratory and cardiovascular stability. Notably, it does not cause respiratory depression, maintaining both the hypercapnic reflex and the residual functional capacity with a moderate bronchodilation effect. In the pediatric population, ketamine can be administered through practically all routes, making it an advantageous drug for the sedation required setting such as placement of difficult vascular access and in uncooperative and oppositional children. Consequently, ketamine is indicated in prehospital induction of anesthesia, induction of anesthesia in potentially hemodynamic unstable patients, and in patients at risk of bronchospasm. Even more, ketamine does not increase intracranial pressure, and it can be safely used also in patients with traumatic brain injuries. This article is aimed to provide a brief and practical summary of the role of ketamine in the pediatric field.

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.

Temporal Trends and Variability in Ketamine Use for Mechanically Ventilated Adults in the United States

Rationale The epidemiology of continuous ketamine use in the management of critically ill adults receiving invasive mechanical ventilation (MV) in the U.S. is unknown. Objective To quantify the temporal trends and variation across U.S. hospitals in continuous ketamine use. Methods We performed a retrospective cohort study of adults (age ≥18) receiving MV who were discharged (alive or dead) from U.S. hospitals contributing data to the Premier Healthcare Database between January 2008 and September 2018. We used mixed effects multivariable logistic regression modeling (fixed effects: patient and hospital characteristics; random effect: discharge hospital) to evaluate the associations of discharge quarter and discharge hospital with continuous ketamine use (defined as a charge for intravenous ketamine on ≥2 consecutive calendar days). Results We identified 2,059,599 MV adults across 842 hospitals; of these, 7,927 (0.4%) received continuous ketamine. Ketamine use increased over time from 0.07% of all patients in quarter 1 2008 to 1.1% of all patients in quarter 3 2018. After adjustment, the odds of receiving continuous ketamine were consistently increased starting in quarter 4 2011 (odds ratio [95% confidence interval]: 1.83 [1.09-3.06] vs quarter 1 2008, p=0.023) with >10-fold increased odds starting in quarter 2 2017. Out of 842 hospitals, 486 (57.7%) used continuous ketamine on at least one cohort patient during the study period. Across these hospitals ever using ketamine, median use was 0.2% (IQR 0.08%-0.5%) with 5 hospitals using continuous ketamine in >5% of patients. The adjusted median odds ratio for discharge hospital was 3.72 (95% confidence interval: 3.37-4.13) which was higher than the odds ratio for any patient or hospital covariable other than discharge quarter. Conclusions In U.S. hospitals, use of continuous infusion ketamine increased markedly over time in critically ill patients receiving MV, with substantial variability between hospitals. Given the unique properties of ketamine as a sedative, further research is needed to assess its safety and utility in critically ill populations.

Hemodynamic Effects of Ketamine Compared With Propofol or Dexmedetomidine as Continuous ICU Sedation

BACKGROUND

Ketamine has seen increased use for sedation in the intensive care unit. In contrast to propofol or dexmedetomidine, ketamine may provide a positive effect on hemodynamics.

OBJECTIVE

The objective of this study was to compare the development of clinically significant hypotension or bradycardia (ie, negative hemodynamic event) between critically ill adults receiving sedation with ketamine and either propofol or dexmedetomidine.

METHODS

This was a retrospective cohort study of adults admitted to an intensive care unit at an academic medical center between January 2016 and January 2021.

RESULTS

Patients in the ketamine group (n = 78) had significantly less clinically significant hypotension or bradycardia compared with those receiving propofol or dexmedetomidine (n = 156) (34.6% vs 63.5%; P < 0.001). Patients receiving ketamine also experienced smaller degree of hypotension observed by percent decrease in mean arterial pressure (25.3% [17.4] vs 33.8% [14.5]; P < 0.001) and absolute reduction in systolic blood pressure (26.5 [23.8] vs 42.0 [37.8] mm Hg; P < 0.001) and bradycardia (15.5 [24.3] vs 32.0 [23.0] reduction in beats per minute; P < 0.001). In multivariate logistic regression modeling, receipt of propofol or dexmedetomidine was the only independent predictor of a negative hemodynamic event (odds ratio [OR]: 3.3, 95% confidence interval [CI], 1.7 to 6.1; P < 0.001).

CONCLUSION AND RELEVANCE

Ketamine was associated with less clinically relevant hypotension or bradycardia when compared with propofol or dexmedetomidine, in addition to a smaller absolute decrease in hemodynamic parameters. The clinical significance of these findings requires further investigation.

Approach to Sedation and Analgesia in COVID-19 Patients on Venovenous Extracorporeal Membrane Oxygenation

OBJECTIVE

To describe clinically pertinent challenges of managing sedation in COVID-19 patients on venovenous extracorporeal membrane oxygenation (VV-ECMO) and describe considerations for enhanced safety and efficacy of pharmacological agents used.

DATA SOURCES

A PubMed search was performed using the following search terms: ECMO, ARDS, sedation, COVID-19, coronavirus, opioids, analgesia, fentanyl, hydromorphone, morphine, oxycodone, methadone, ketamine, propofol, dexmedetomidine, clonidine, benzodiazepines, midazolam, lorazepam, and diazepam.

STUDY SELECTION AND DATA EXTRACTION

Relevant clinical and pharmacokinetic studies were considered. All studies included were published between January 1988 and March 2021.

DATA SYNTHESIS

Patients with acute respiratory distress syndrome secondary to COVID-19 may progress to requiring VV-ECMO support. Agents frequently used for sedation and analgesia in these patients have been shown to have significant adsorption to ECMO circuitry, leading to possible diminished clinical efficacy. Use of hydromorphone-based analgesia has been associated with improved clinical outcomes in patients on VV-ECMO. However, safety and efficacy regarding use of other agents in this patient population remains an area of further research.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

This review addresses clinical challenges associated with sedation management in COVID-19 patients requiring VV-ECMO support and provides potential strategies to overcome these challenges.

CONCLUSIONS

Historically, sedation and analgesia management in patients requiring ECMO support have posed a challenge for bedside clinicians given the unique physiological and pharmacokinetic changes in this patient population. A multimodal strategy to managing analgesia and sedation should be used, and the use of enteral agents may play a role in reducing parenteral agent requirements.

Comeback of ketamine: resurfacing facts and dispelling myths

Initially known as CI-581, ketamine was first synthesized in 1962 as a replacement from phencyclidine. It has since been used as an anesthetic and analgesic. In addition, it has bronchodilating, sedative, and amnestic properties, preserving airway reflexes and sympathetic nervous system tone. Since the discovery of ketamine, it has been a major topic of discussion due to controversies regarding its usage in particular sets of patients. In the past 50 years, despite its potential benefits, it is not commonly used because of concerns of "emergence phenomenon," its use as a substance of abuse, and its systemic side effects. Since 2012, three World Health Organization reviews on ketamine have addressed its international control. Researchers have been studying this wonder drug for a decade worldwide. Many myths of ketamine regarding emergence phenomenon and its use in traumatic brain injury and open eye injury have been disproved in recent times. It is becoming popular in pre-hospital settings, critical care, emergency medicine, low-dose acute pain services, and adjuvant in regional anesthesia techniques. This review highlights the current consensus on the various applications of ketamine in the literature.

Evidence-Based Guideline for Adult Sedation, Pain Assessment, and Analgesia in a Low Resource Setting Intensive Care Unit: Review Article

Background

Agitation and anxiety occur frequently in ICU and affect about 30–80% of patients in ICU present with delirium worldwide, and it is associated with adverse clinical outcomes. This review aimed to systematically review articles and finally draw an evidence-based guideline for an area with limited resources.

Methods

The review was reported based on preferred reporting items for systemic and meta-analysis (PRISMA) protocol. We searched literature from PubMed, Google Scholar, and Medline database using keywords like the level of sedation, sedation score, pain assessment in ICU, and sedative drugs in ICU from an article published in English. After extraction with a patient population and exclusion, five randomized clinical trials, four systemic reviews and meta-analysis, four observation cohort study, and two practical guidelines were used for the review.

Conclusion

In addition to high validity and reliability, RASS has the advantage of easiness to remember for nurses making it a preferred sedation assessment tool in an adult ICU setting. Light sedation with daily interruption was recommended with an aim of an awake and alert patient ready for the weaning trial. Propofol was preferred when sedation is for a short duration and when intermittent awakening is required. Ketamine is the preferred induction for asthmatic hypotensive and patient requiring prolonged continuous sedation. With a similar time for sedation, diazepam shows a shorter time for intubation compared to midazolam. Besides diazepam has shown a cheaper cost of sedation than midazolam. This makes it a drug of preference in a low resource setting.

Supportive Management and Interventions for Respiratory Failure Due to SARS-CoV-2

Severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) infection can vary from asymptomatic to severe symptoms. It can lead to respiratory failure and acute respiratory distress syndrome requiring intubation and mechanical ventilation. Triaging patients is key to prevent spread, conserving medical resources, and providing appropriate care. The treatment of these patients remains supportive. Respiratory failure due to the virus should be managed by providing supplemental oxygen and early intubation. Some patients develop acute respiratory distress syndrome and refractory hypoxemia. In this article, we review the 2 phenotypes of respiratory failure, mechanical ventilation and the management of refractory hypoxemia.

Safety and Effectiveness of Sedation With Adjunctive Ketamine Versus Nonketamine Sedation in the Medical Intensive Care Unit

BACKGROUND

Ketamine, an N-methyl-d-aspartate receptor antagonist with sedative and analgesic properties, is becoming more popular as an adjunctive sedative in the critically ill patients.

METHODS

We conducted a single center, retrospective cohort study of patients admitted to the medical intensive care unit (MICU) between 2013 and 2018. Patients who received continuous infusion ketamine or nonketamine sedatives (NKS) including dexmedetomidine, fentanyl, midazolam, or propofol were identified. The primary outcome was percentage of Richmond Agitation-Sedation Scale (RASS) scores at goal in patients receiving ketamine as adjunct to NKS compared to those on NKS alone.

RESULTS

A total of 172 patients were included (n = 86 ketamine, n = 86 NKS). Baseline characteristics were similar with the exception of antipsychotic use, which was higher in the ketamine group (P = .008). Percentage of RASS scores at goal was not different between groups (78.7% vs 81.4%, P = .29). Fewer patients in the ketamine group received continuous infusion fentanyl (76.7% vs 94.2%, P = .002). Patients on adjunctive ketamine required fewer days of intermittent benzodiazepines (0 [0-1] vs 1 [1-2], P < .0001). Patients receiving ketamine required less norepinephrine, receiving a median of 6.32 mg (2.4-20) versus 11.7 mg (5.2-45.2; P = .03). There was no difference in receipt of new antipsychotics or occurrence of arrhythmias.

CONCLUSION

Addition of ketamine did not increase the percentage of RASS scores at goal versus NKS but was well tolerated. Ketamine was associated with reductions in norepinephrine requirements, days of intermittent benzodiazepine administration, and number of patients receiving continuous infusion fentanyl. Continuous infusion ketamine appears safe and effective for sedation in the MICU.

Continuous Infusion Ketamine for Adjunctive Analgosedation in Mechanically Ventilated, Critically Ill Patients

OBJECTIVE

Ketamine is an N-methyl-D-aspartate antagonist with emerging evidence assessing its use as a continuous infusion agent to provide concomitant analgesia and sedation. The role of ketamine as adjunctive therapy in mechanically ventilated patients is unclear. This study sought to investigate the impact of adjunctive continuous infusion ketamine on concomitant analgesic and sedative dosing while providing goal comfort in mechanically ventilated patients.

METHODS

This retrospective two-center intrapatient comparison study included mechanically ventilated adult ICU patients who received continuous infusion ketamine with at least one other analgesic or sedative infusion. The primary outcome assessed percent relative change in concomitant analgesic-sedative doses 24 hours after ketamine initiation. Secondary outcomes included percent of Richmond Agitation and Sedation Score (RASS) assessments at goal, adverse effects, and delirium incidence. Exploratory evaluation of independent factors associated with ketamine responders (50% or more relative reduction in analgesic-sedative dosing requirements at 24 hrs) and nonresponders (less than 50% relative reduction) was performed using multivariate logistic regression.

RESULTS

Overall, 104 patients were included. A total of 160 concomitant analgesic-sedative infusions were used in combination with ketamine, most commonly fentanyl (98 [61.3%]) and propofol (46 [28.8%]). A 20% (interquartile range [IQR] -63.6 to 0.0, p<0.001) relative reduction in total analgesic-sedative infusion pharmacotherapy was achieved at 24 hours after ketamine initiation. Analgesic and sedative infusion doses decreased at 24 hours (fentanyl: pre, 175 μg/hr [IQR 100-200 μg/hr] vs post, 125 μg/hr [IQR 50-200 μg/hr], p<0.001; propofol: pre, 42.5 μg/kg/min [IQR 20.0-60.0 μg/kg/min] vs post, 20.0 μg/kg/min [IQR 3.8-31.3 μg/kg/min], p<0.001). Median percent time within goal RASS improved after ketamine initiation (pre, 7.1% [0-40%] vs post, 25% [0-66.7%], p=0.005). No differences were observed in secondary outcomes between responders and nonresponders, except a longer non-ICU hospital length of stay in responders. Independent factors associated with ketamine response included a lower body mass index, higher starting dose of ketamine, lower severity of illness, and need for multiple concomitant analgesic-sedative infusions before initiation of ketamine.

CONCLUSIONS

Adjunctive continuous infusion ketamine promotes analgesic and sedative dose-sparing effects in mechanically ventilated patients while improving time spent within goal sedation range. Further prospective research is warranted.

Ketamine Infusion in Post-Surgical Pain Management after Head and Neck Surgery: A Retrospective Observational Study

Background:

Head and neck cancer affects approximately 382,000 new patients per year worldwide with a significant portion undergoing surgical treatment. During postoperative period key elements in the Intensive Care Unit (ICU) are airway management and pain control.

Objective:

We evaluated the average change of inpatient pain control using a Numerical Rating Score (NRS). We also evaluated the time of extubation after ICU admission recording the incidence of desaturation and the necessity of re-intubation. Secondary outcomes were the incidence of postoperative complications, included those narcotics-related, and the use of rescue analgesics.

Methods:

In this retrospective observational study, we analyzed data of registry before and after we have changed our postoperative analgesic protocol from remifentanil infusion to ketamine infusion.

Results:

Medical records of 20 patients were examined. 10 patients received 0.5 mg/kg ketamine bolus at the end of surgery, followed by a continuous infusion of 0.25 mg/kg/h. All patients presented a significant decrease in pain intensity from the 4th to 48th postoperative hour (p < 0.05), but statically not a significant difference in NRS score was recorded between the two groups. Time to extubation was shorter in ketamine group compared to the remifentanil group (112.30 min ± 16.78 vs. 78 min ± 14.17; p < 0.05). Desaturation rate was 10% in the remifentanil group, while no case was recorded in the ketamine group.

Conclusion:

The level of analgesia provided by ketamine and remifentanil was comparable. Ketamine was superior in ventilatory management of the patient with more rapid extubation and with no case of desaturation.

Alternatives to Rapid Sequence Intubation: Contemporary Airway Management with Ketamine

Endotracheal intubation (ETI) is a high-risk procedure commonly performed in emergency medicine, critical care, and the prehospital setting. Traditional rapid sequence intubation (RSI), the simultaneous administration of an induction agent and muscle relaxant, is more likely to harm patients who do not allow appropriate preparation and preoxygenation, have concerning airway anatomy, or severe hypoxia, acidemia, or hypotension. Ketamine, a dissociative anesthetic, can be used to facilitate two alternatives to RSI to augment airway safety in these scenarios: delayed sequence intubation - the use of ketamine to allow airway preparation and preoxygenation in the agitated patient; and ketamine-only breathing intubation, in which ketamine is used without a paralytic to facilitate ETI as the patient continues to breathe spontaneously. Ketamine may also provide hemodynamic benefits during standard RSI and is a valuable agent for post-intubation analgesia and sedation. When RSI is not an optimal airway management strategy, ketamine's unique pharmacology can be harnessed to facilitate alternative approaches that may increase patient safety.

Safety and Utility of Continuous Ketamine Infusion for Sedation in Mechanically Ventilated Pediatric Patients

OBJECTIVES

The selection of sedative medications for mechanically ventilated pediatric patients remains an ongoing clinical challenge. Although continuous ketamine infusion has been used in this population, support for its use remains largely anecdotal. This study describes a single institution's use of ketamine infusions as part of a sedation protocol in the pediatric intensive care unit (PICU).

METHODS

This was a retrospective study of children who received ketamine infusions as part of a multidrug sedation protocol in a 12-bed PICU at a tertiary children's hospital. Outcomes included effectiveness of ketamine infusion in providing adequate sedation as determined by State Behavioral Scale (SBS) scores and incidence of adverse events.

RESULTS

A total of 22 children receiving ketamine continuous infusion as part of a multidrug sedation protocol from February 2014 through October 2015 were eligible and enrolled in the study. Ketamine continuous infusion was administered in addition to at least 2 other sedation infusions at an average rate of 1.02 ± 0.50 mg/kg/hr, with a range of 0.07 to 2.0 mg/kg/hr. The duration of ketamine was 65.7 ± 41.01 hours, with a range of 19 to 153 hours. There was no significant change in SBS scores before and after initiation of ketamine infusion. Although not statistically significant, patients with inadequate sedation prior to starting ketamine required fewer bolus sedation doses and had improved sedation after ketamine was started. There were no reported adverse events.

CONCLUSIONS

The addition of a ketamine infusion as part of a multidrug sedation regimen was at least as effective as patients' regimen prior to ketamine addition in this population of intubated pediatric patients, with no adverse events.

Adjunctive Use of Ketamine for Benzodiazepine-Resistant Severe Alcohol Withdrawal: a Retrospective Evaluation

INTRODUCTION

Benzodiazepine (BZD)-resistant alcohol withdrawal remains a challenge for most institutions due to limited evidence with available agents. One published study currently exists utilizing the N-methyl-D-aspartate antagonist, ketamine, for alcohol withdrawal.

OBJECTIVE

The purpose of our study was to evaluate the effect of adjunctive ketamine continuous infusion on symptom control and lorazepam infusion requirements for BZD-resistant alcohol withdrawal patients in the intensive care unit.

METHODS

A retrospective review was conducted of patients receiving ketamine adjunctively with a lorazepam infusion for severe alcohol withdrawal between August 2012 and August 2014. Outcomes included time to symptom control, lorazepam infusion requirements, ketamine initial and maximum daily infusion rates, and adverse effects of ketamine.

RESULTS

Thirty patients were included in the analysis. Mean time to initiation of ketamine after the initiation of a lorazepam infusion was 41.4 h. All patients achieved initial symptom control within 1 h of ketamine initiation. Median initial ketamine infusion rate was 0.75 mg/kg/h and the average maximum daily rate was 1.6 mg/kg/h. Significant decreases in lorazepam infusion rates from baseline were observed at 24 h (- 4 mg/h; p = 0.01) after ketamine initiation. No patients experienced documented CNS adverse effects. Two patients experienced hypertension and no patients experienced tachycardia related to ketamine.

CONCLUSION

Adjunctive ketamine could provide symptom control for BZD-refractory patients and may potentially reduce lorazepam infusion requirements. Future studies to determine optimal dosing, timing of initiation, and place in therapy for BZD-resistant alcohol withdrawal are needed. The mechanism of action via the NMDA receptor with ketamine may provide benefit for BZD-resistant alcohol withdrawal.

Comparison of Ketamine- Versus Nonketamine-Based Sedation on Delirium and Coma in the Intensive Care Unit

BACKGROUND

At this time, there are no studies evaluating the risk of delirium or coma with the use of ketamine in mechanically ventilated adult patients, compared to conventional therapies such as propofol or dexmedetomidine.

OBJECTIVE

The objective of this study was to evaluate the number of days alive without delirium or coma in mechanically ventilated patients in the intensive care unit receiving analgosedation infusions with ketamine versus without ketamine.

METHODS

This was a retrospective cohort study conducted at an academic medical center in the United States. Consecutive mechanically ventilated adult patients between November 2015 and April 2017 were evaluated. Patients were divided into 2 groups based on the sedative regimen used: ketamine based or nonketamine based. The primary outcome was the number of days alive without delirium or coma. The secondary outcomes were incidence of delirium, incidence of coma, and ventilator-free days at day 28.

RESULTS

The study cohort consisted of 79 patients, of which 39 received ketamine- and 40 received nonketamine-based sedation. The number of days alive without delirium or coma was 6 days (interquartile range [IQR]: 2-9 days) with ketamine and 4 days (IQR: 3-7 days) with nonketamine (P = .351). Delirium occurred in 29 (74%) of 39 patients with ketamine and 34 (85%) of 40 patients with nonketamine (P = .274). Coma occurred in 16 (41%) of 39 patients with ketamine and 6 (15%) of 40 patients with nonketamine (P = .013). The median ventilator-free days were 13 days (IQR: 0-23 days) with ketamine and 21 days (0-25 days) with nonketamine (P = .229).

CONCLUSIONS

Sustained ketamine-based sedation in mechanically ventilated patients may be associated with a higher rate of observed coma but similar delirium- and coma-free days compared nonketamine-based regimens.

Impact of Ketamine Use on Adjunctive Analgesic and Sedative Medications in Critically Ill Trauma Patients

BACKGROUND

Ketamine may be used to manage pain and agitation that is refractory to what are usually considered traditional agents such as fentanyl, propofol, benzodiazepines, and dexmedetomidine; however, literature describing the use of ketamine continuous infusions for this purpose in critically ill trauma patients is limited.

OBJECTIVES

The primary objective of this study was to determine the impact of the initiation of a ketamine continuous infusion on sedative and analgesic use in critically ill trauma patients. Secondary objectives were to identify the patient population in which ketamine was initiated, assess the proportion of time patients were at their goal level of sedation, and determine the dosing patterns of adjunctive sedative agents.

METHODS

This single-center retrospective chart review over a 19-month period included critically ill mechanically ventilated adult trauma patients in whom a ketamine continuous infusion was initiated for management of sedation and agitation. Patients who received ketamine for other indications or by the acute pain management service were not included in this evaluation.

RESULTS

Thirty-six patients were included in the study. Patients in whom ketamine was initiated tended to be white men with blunt trauma. Overall, the initiation of ketamine was associated with a decrease in the amount of opioids and propofol used and an increase in the amount of ziprasidone and dexmedetomidine needed to achieve the goal Richmond Agitation Sedation Score. When compared with the time period before ketamine initiation, the proportion of time that patients achieved goal sedation was not significantly different after the addition of ketamine.

CONCLUSIONS

Although the use of ketamine in critically ill mechanically ventilated adult trauma patients was associated with decreased opioid use, it was also associated with increased use of dexmedetomidine and ziprasidone to achieve and maintain sedation. Further examination of clinical outcomes associated with these differences in drug use in a larger population of trauma patients is warranted before routine use of ketamine for analgesia and sedation can be recommended.

Ketamine for analgosedation in critically ill patients

PURPOSE

The purpose of this narrative review is to provide practical and useful guidance for clinicians considering the use of intravenous ketamine for its analgosedative properties in adult, critically ill patients.

METHODS

MEDLINE was searched from inception until January 2016. Articles related to the pharmacological properties of ketamine were retrieved. Information pertaining to pharmacology, pharmacokinetics, dosing regimens, adverse effects, and outcomes was obtained from relevant studies.

RESULTS

Although the primary mechanism for ketamine's pharmacological effects is N-methyl-d-aspartate blockade, there are several potential mechanisms of action. It has a very large volume of distribution due to its lipophilicity, which can lead to drug accumulation with sustained infusions. Ketamine has several advantages compared with conventional sedatives such as preserving pharyngeal and laryngeal protective reflexes, lowering airway resistance, increasing lung compliance, and being less likely to produce respiratory depression. It causes sympathetic stimulation, which is also unlike other sedatives and analgesics. There are psychotomimetic effects, which are a concern in terms of delirium. Dosing and monitoring recommendations are provided.

CONCLUSIONS

Ketamine has a unique pharmacological profile compared with more traditional agents such as opioids, which makes it an appealing alternative agent for analgosedation in the intensive care unit setting.

The Future of Intensive Care Unit Sedation: A Report of Continuous Infusion Ketamine as an Alternative Sedative Agent

This report describes a patient case utilizing a nontraditional sedative, continuous infusion ketamine, as an alternative agent for intensive care unit (ICU) sedation. A 27-year-old female presented for neurosurgical management of a coup contrecoup injury, left temporal fracture, epidural hemorrhage (EDH), and temporal contusion leading to sustained mechanical ventilation. The patient experienced profound agitation during mechanical ventilation and developed adverse effects with all traditional sedatives: benzodiazepines, dexmedetomidine, opioids, and propofol. Ketamine was titrated to effect and eliminated the need for other agents. This led to successful ventilator weaning, extubation, and transition of care. Given the unique side effect profile of ketamine, it is imperative that information is disseminated on potential utilization of this agent. More information is needed regarding dosing, monitoring, and long-term effects of utilizing ketamine as a continuous ICU sedative, but given the analgesia, anesthesia, and cardiopulmonary stability, future utilization of this medication for this indication seems promising.

Is ketamine a lifesaving agent in childhood acute severe asthma?

Children with acute severe asthma exacerbation are at risk of developing respiratory failure. Moreover, conventional aggressive management might be futile in acute severe asthma requiring intubation and invasive ventilation. The aim of this review is to detail evidence on the use of ketamine in childhood asthma exacerbations. A search of the MEDLINE, EMBASE, and Cochrane databases was performed, using different combinations of the following terms: ketamine, asthma, use, exacerbation, and childhood. In addition, we searched the references of the identified articles for additional articles. We then reviewed titles and included studies that were relevant to the topic of interest. Finally, the search was limited to studies published in English and Spanish from 1918 to June 2015. Due to the scarcity in the literature, we included all published articles. The literature reports conflicting results of ketamine use for acute severe asthma in children. Taking into consideration the relatively good safety profile of the drug, ketamine might be a reasonable option in the management of acute severe asthma in children who fail to respond to standard therapy. Furthermore, pediatricians and pediatric emergency clinicians administering ketamine should be knowledgeable about the unique actions of this drug and its potential side effects.

Ketamine for Analgosedation in the Intensive Care Unit: A Systematic Review

OBJECTIVE

To evaluate the evidence for the use of intravenous ketamine for analgosedation in the intensive care unit.

METHODS

MEDLINE and EMBASE were queried from inception until July 2015. Search terms used included ketamine, intensive care, and critical care. The search retrieved 584 articles to be screened for inclusion. The intent was to include randomized controlled studies using sustained intravenous infusions (>24 hours) of ketamine in the critically ill patients.

RESULTS

One trial evaluated opioid consumption as an outcome in postoperative critically ill patients who were randomized to ketamine or saline infusions. The mean cumulative morphine consumption at 48 hours was significantly lower in the ketamine group (58 ± 35 mg) compared to the morphine-only group (80 ± 37 mg; P < .05). Other trials showed the potential safety of ketamine in terms of cerebral hemodynamics in patients with traumatic brain injury, improved gastrointestinal motility, and decreased vasopressor requirements. The observational study and case reports suggest that ketamine is safe and effective and may have a role in patients who are refractory to other therapies.

CONCLUSION

Ketamine use may decrease analgesic consumption in the intensive care unit. Additional trials are needed to further delineate the role of ketamine for analgosedation.

Evidence and consensus based guideline for the management of delirium, analgesia, and sedation in intensive care medicine. Revision 2015 (DAS-Guideline 2015) - short version

In 2010, under the guidance of the DGAI (German Society of Anaesthesiology and Intensive Care Medicine) and DIVI (German Interdisciplinary Association for Intensive Care and Emergency Medicine), twelve German medical societies published the “Evidence- and Consensus-based Guidelines on the Management of Analgesia, Sedation and Delirium in Intensive Care”. Since then, several new studies and publications have considerably increased the body of evidence, including the new recommendations from the American College of Critical Care Medicine (ACCM) in conjunction with Society of Critical Care Medicine (SCCM) and American Society of Health-System Pharmacists (ASHP) from 2013. For this update, a major restructuring and extension of the guidelines were needed in order to cover new aspects of treatment, such as sleep and anxiety management. The literature was systematically searched and evaluated using the criteria of the Oxford Center of Evidence Based Medicine. The body of evidence used to formulate these recommendations was reviewed and approved by representatives of 17 national societies. Three grades of recommendation were used as follows: Grade “A” (strong recommendation), Grade “B” (recommendation) and Grade “0” (open recommendation). The result is a comprehensive, interdisciplinary, evidence and consensus-based set of level 3 guidelines. This publication was designed for all ICU professionals, and takes into account all critically ill patient populations. It represents a guide to symptom-oriented prevention, diagnosis, and treatment of delirium, anxiety, stress, and protocol-based analgesia, sedation, and sleep-management in intensive care medicine.