Recurrent episodes of intractable laryngospasm during dissociative sedation with intramuscular ketamine

Comparing the Safety and Effectiveness of Ketamine Versus Benzodiazepine/Opioid Combination for Procedural Sedation in Emergency Medicine: A Comprehensive Review and Meta-Analysis

Procedural sedation is essential in the ED to conduct painful procedures effectively. Ketamine and benzodiazepines/opioids are commonly used, with ketamine providing adequate analgesia and preserving airway muscle tone. However, ketamine is associated with adverse effects while benzodiazepines/opioids can lead to respiratory depression. This study compares the safety and efficacy of ketamine and midazolam/fentanyl. Two search methods were used to identify studies related to our topic, including a database search and a manual search involving screening reference lists of articles retrieved by the database search. A methodological quality appraisal was conducted on the articles suitable for inclusion using Cochrane's risk of bias tool in the Review Manager software (Review Manager (RevMan) (Computer program). Version 5.4, The Cochrane Collaboration, 2020). Moreover, pooled analysis was performed using the Review manager software. The study analyzed 1366 articles, of which seven were included for analysis. Pooled data showed that ketamine and midazolam/fentanyl had similar effects on pain scores during procedures and sedation depth measured by the University of Michigan sedation scale. However, the Modified Ramsay Sedation Score showed significantly more profound sedation in the ketamine group. The only significant adverse events were vomiting and nausea, which had a higher incidence in the ketamine group. Our data suggest that ketamine is as effective as the midazolam/fentanyl combination for procedural sedation but is associated with higher incidences of adverse events. Therefore, midazolam/fentanyl can be recommended for procedural sedation in the ED. However, it should be provided in the presence of a physician comfortable with airway management due to high incidences of oxygen desaturation.

Continuous Rate Infusion of Ketamine Hydrochloride and Dexmedetomidine for Maintenance of Anesthesia during Laryngotracheal Surgery in New Zealand White Rabbits (Oryctolagus cuniculus)

New Zealand white rabbits (Oryctolagus cuniculus) are an established in vivo model for the study of structural and functional consequences of vocal-fold vibration. Research design requires invasive laryngotracheal procedures, and the presence of laryngospasms or pain responses (or both) hinder phonation-related data collection. Published anesthesia regimens report respiratory depression and muscle tone changes and have been unsuccessful in mitigating autonomic laryngeal responses in our protocol. Infusion of ketamine hydrochloride and dexmedetomidine hydrochloride in pediatric medicine provides effective analgesia and sedation for laryngotracheal procedures including intubation and bronchoscopy; however, data evaluating the use of ketamine-dexmedetomidine infusion in rabbits are unavailable. This study reports a new infusion regimen, which was used in 58 male New Zealand white rabbits that underwent a nonsurvival laryngotracheal procedure to induce phonotraumatic vocal-fold injury. Animals were sedated by using ketamine hydrochloride (20 mg/kg IM) and dexmedetomidine (0.125 mg/kg IM). Maintenance anesthesia was provided by using continuous rate intravenous infusion of ketamine hydrochloride (343 μg/kg/min) and dexmedetomidine (1.60 μg/kg/min). A stable plane of anesthesia with no autonomic laryngeal response (laryngospasm) was achieved in 32 of the 58 rabbits (55%). Laryngospasms occurred in 25 of 58 animals (43%) and were controlled in 20 cases (80%) by providing 0.33 mL 2% topical lidocaine, incremental increase in infusion rate, or both. Continuous rate infusion of ketamine hydrochloride-dexmedetomidine with prophylactic topical lidocaine provides a predictable and adjustable surgical plane of anesthesia, with minimal confounding respiratory and autonomic laryngeal responses, during extended-duration laryngotracheal surgery in rabbits. This regimen should be considered as an alternative to injection maintenance for prolonged, invasive procedures.

Procedural sedation and analgesia for pediatric shock wave lithotripsy: a 10 year experience of single institution

The aim of this study was to evaluate anesthesia practice for pediatric extracorporeal shock wave lithotripsy (ESWL) according to the age groups and discuss the anesthetic management of these patients. Pediatric patients treated with ESWL because of urolithiasis under anesthesia in our department between December 2007 and January 2017 were evaluated retrospectively. A total of 251 patients were divided into two groups as Group PS: preschool children (<6 years) and Group S: school children (≥6 years). Groups were compared according to ketamine and midazolam doses, extra anesthetic agent requirement, duration of procedure, procedural and postprocedural complications due to anesthesia, as well as mean number of sessions and calculus diameter. A total of 408 sessions of ESWL were applied to 251 children included in the study. Overall, mean age of the patients was 4.5 ± 3.2 years (7 months-14 years). In school children (Group S), mean ketamine and midazolam doses were significantly higher than the preschool group (p < 0.01 and p = 0.04, respectively). There was no statistically significant difference in additional anesthetic agent requirement (p = 0.35) as well as mean number of SWL sessions (p = 0.23), duration of anesthesia (p = 0.93), stone size (p = 0.20), and stone laterality (p = 0.71) in both preschool and school children. No severe complications were observed in both groups. In pediatric ESWL patients, ketamine-midazolam combination is an effective and safety choice for outpatient anesthesia. Appropriate dose adjustment in a monitorized and well-equipped setting is essential.

Respiratory complications associated with ketamine anesthesia for ophthalmic procedures following intraocular pressure measurement in children

BACKGROUND

We compared respiratory complications (RCs) in children who received intramuscular (IM) versus intravenous (IV) or no ketamine for intraocular pressure (IOP) measurement to test our observation that IM ketamine is associated with higher incidence of RCs.

MATERIALS AND METHODS

We analyzed 149 eye examinations under anesthesia with ketamine in 27 patients and 263 non-ketamine examinations under anesthesia in 81 patients using a mixed effects logistic regression model.

RESULTS

IM KETAMINE WAS STRONGLY ASSOCIATED WITH INCREASED ODDS OF RCS COMPARED TO NO KETAMINE (ODDS RATIO (OR): 20.23, P < 0.0001) and to IV ketamine (OR: 6.78, P = 0.02), as were higher American Society of Anesthesiologists (ASA) classification (OR: 2.60, P = 0.04), and the use of volatile agents (OR: 3.32, P = 0.02).

CONCLUSION

Further studies should be conducted to confirm our observation of increased RCs with IM ketamine.

Procedural sedation: A review of sedative agents, monitoring, and management of complications

Given the continued increase in the complexity of invasive and noninvasive procedures, healthcare practitioners are faced with a larger number of patients requiring procedural sedation. Effective sedation and analgesia during procedures not only provides relief of suffering, but also frequently facilitates the successful and timely completion of the procedure. However, any of the agents used for sedation and/or analgesia may result in adverse effects. These adverse effects most often affect upper airway patency, ventilatory function or the cardiovascular system. This manuscript reviews the pharmacology of the most commonly used agents for sedation and outlines their primary effects on respiratory and cardiovascular function. Suggested guidelines for the avoidance of adverse effects through appropriate pre-sedation evaluation, early identification of changes in respiratory and cardiovascular function, and their treatment are outlined.

Laryngospasm during emergency department ketamine sedation: a case-control study

OBJECTIVE

The objective of this study was to assess predictors of emergency department (ED) ketamine-associated laryngospasm using case-control techniques.

METHODS

We performed a matched case-control analysis of a sample of 8282 ED ketamine sedations (including 22 occurrences of laryngospasm) assembled from 32 prior published series. We sequentially studied the association of each of 7 clinical variables with laryngospasm by assigning 4 controls to each case while matching for the remaining 6 variables. We then used univariate statistics and conditional logistic regression to analyze the matched sets.

RESULTS

We found no statistical association of age, dose, oropharyngeal procedure, underlying physical illness, route, or coadministered anticholinergics with laryngospasm. Coadministered benzodiazepines showed a borderline association in the multivariate but not univariate analysis that was considered anomalous.

CONCLUSIONS

This case-control analysis of the largest available sample of ED ketamine-associated laryngospasm did not demonstrate evidence of association with age, dose, or other clinical factors. Such laryngospasm seems to be idiosyncratic, and accordingly, clinicians administering ketamine must be prepared for its rapid identification and management. Given no evidence that they decrease the risk of laryngospasm, coadministered anticholinergics seem unnecessary.

[Laryngospasm]

BACKGROUND AND OBJECTIVES

Airways management is fundamental for anesthesiologists, especially during induction of anesthesia and after extubation, when laryngeal spasm is more common. The anesthesiologist should know pharyngeal-laryngeal physiology and the risk factors for airways obstruction, since this is a potentially severe complication with a multifactorial etiology that can develop during anesthesia and whose consequences can be catastrophic. A delay in the diagnosis or treatment and its evolution can lead to hypoxemia, acute pulmonary edema, and, eventually, death of the patient. In this context, the objective of this report was to review the measures that should be taken in cases of laryngospasm because adequate oxygenation and ventilation may be compromised in this situation.

CONTENTS

This review article presents the mechanisms of airways management, discussing the most relevant aspects and etiology, pathophysiology, treatment, and prevention of laryngospasm.

CONCLUSIONS

The literature has several recommendations on the treatment or prevention of laryngospasm, but none of them is completely effective. Due to its severity, further studies on measures to prevent this complication are necessary.

Serious adverse events during procedural sedation with ketamine

OBJECTIVES

Compare the frequency of respiratory adverse events between patients who received intramuscular (IM) versus intravenous ketamine.

METHODS

Case control study from 1997 to 2005 at a large urban pediatric emergency department. Adverse events were defined as apnea, hypoxemia (oximetry <93%), hypoventilation, laryngospasm, and other upper airway obstruction. Serious adverse events were defined by the level of intervention and included those cases that required positive pressure ventilation, insertion of oral or nasal airway, or endotracheal intubation. Minor adverse events were respiratory events requiring minimal intervention (stimulation, supplemental O2, airway repositioning). Controls (2:1) were selected by the next chronological patient in the data set who received ketamine but had no respiratory adverse event.

RESULTS

Four thousand two hundred fifty-two patients received ketamine; 102 cases (2.4%) had respiratory adverse events, including 38 patients with severe adverse events (0.9%). Interventions for the cases included supplemental O2 (59/102, 58%), airway repositioning (36/102, 35%), continuous positive airway pressure (7/102, 7%), positive pressure ventilation (33/102, 32%), nasal airway (2/102, 2%), oral airway (1/102, 1%), stimulation (11/102, 11%), and intubation (1/102, 1%). Overall, 33% of all subjects received IM ketamine including 47% of cases and 27% of controls. Intramuscular IM ketamine was associated with increased likelihood of adverse events (odds ratio [OR] 2.1, 95% CI, 1.3-3). Twenty (69%) of the 29 patients with laryngospasm received IM ketamine (OR, 5.2; 95% CI, 2.3-11.9) and 20 (53%) of the 38 patients who had severe events were administered IM (OR, 2.4; 95% CI, 1.2-4.9). Use of pre-sedation morphine or combined administration with midazolam and/or atropine was not associated with adverse events. Specific procedures were not associated with increased adverse events.

CONCLUSIONS

Respiratory adverse events with ketamine are uncommon. Serious events, like laryngospasm, are rare but occur more commonly with IM administration. This increased risk associated with IM administration should be considered in the sedation plan.