Anaesthesia in haemodynamically compromised emergency patients: does ketamine represent the best choice of induction agent?

A review of equine anesthetic induction: Are all equine anesthetic inductions "crash" inductions?

Horses are the most challenging of the common companion animals to anesthetize. Induction of anesthesia in the horse is complicated by the fact that it is accompanied by a transition from a conscious standing position to uncconconscious recumbency. The purpose of this article is to review the literature on induction of anesthesia with a focus on the behavioral and physiologic/pharmacodynamic responses and the actions and interactions of the drugs administered to induce anesthesia in the healthy adult horse with the goal of increasing consistency and predictability.

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.

Cardiac arrest in obstetric patients receiving anaesthetic care: results from the 7th National Audit Project of the Royal College of Anaesthetists

The 7th National Audit Project (NAP7) of the Royal College of Anaesthetists studied peri-operative cardiac arrest. Additional inclusion criteria for obstetric anaesthesia were: cardiac arrest associated with neuraxial block performed by an anaesthetist outside the operating theatre (labour epidural analgesia); and cardiac arrest associated with remifentanil patient-controlled analgesia. There were 28 cases of cardiac arrest in obstetric patients, representing 3% of all cardiac arrests reported to NAP7, giving an incidence of 7.9 per 100,000 (95%CI 5.4-11.4 per 100,000). Obstetric patients were approximately four times less likely to have a cardiac arrest during anaesthesia care than patients having non-obstetric surgery. The single leading cause of peri-operative cardiac arrest in obstetric patients was haemorrhage, with underestimated severity and inadequate early resuscitation being contributory factors. When taken together, anaesthetic causes, high neuraxial block and bradyarrhythmia associated with spinal anaesthesia were the leading causes overall. Two patients had a cardiac arrest related to labour neuraxial analgesia. There were no cardiac arrests related to failed airway management or remifentanil patient-controlled analgesia.

Efficacy and safety of ketamine for pediatric and adolescent super-refractory status epilepticus and the effect of cerebral inflammatory conditions

OBJECTIVE

To investigate the short-term benefits and adverse effects of ketamine in the treatment of pediatric and adolescent super-refractory status epilepticus (SRSE), with a focus on the inflammatory etiology.

METHODS

This retrospective observational cohort study included a consecutive series of 18 pediatric to adolescent patients with SRSE admitted between 2008 and 2023 and treated with ketamine. Seizure frequency per hour before and after ketamine administration and response rate were calculated. Neurological decline, catecholamine administration, and adverse effects were also assessed. The patients were divided into inflammatory and non-inflammatory etiology groups.

RESULTS

The median age at SRSE onset was 1 year 5 months (range: 11 days-24 years), and 78% of the patients were male individuals. The median duration of treatment was 7.5 days (interquartile range: 2.8-15.5 days). Fifteen (83%) patients achieved >50% seizure reduction. The median seizure frequency before and after ketamine treatment was 5.9 and 0.9, respectively, showing a significant reduction in seizure frequency (p < 0.0001). Ten patients had inflammatory etiologies including bacterial meningitis (n = 2), viral encephalitis (n = 3), and febrile infection related epilepsy syndrome (n = 5). The inflammatory etiology group required a longer treatment duration (p = 0.0453) and showed lower seizure reduction (p = 0.0264), lower response rate (p = 0.0044), and higher neurological decline (p = 0.0003) than the non-inflammatory etiology group. Three (17%) patients experienced transient adverse events requiring intervention within 24 h of initiating ketamine administration.

CONCLUSIONS

Ketamine administration was associated with fewer serious adverse events and a reduced seizure frequency. Additionally, inflammatory conditions may weaken the efficacy of ketamine in patients with SRSE.

Successful treatment of severe calcium channel blocker poisoning, new experience with the guidance of invasive hemodynamic monitoring in a 17-year-old girl: a case report

BACKGROUND

Calcium channel blocker poisoning is one of the most lethal cardiac drugs overdoses. Calcium and high-dose insulin infusion are the first-line therapy for symptomatic patients, and Intralipid emulsion infusion is useful for refractory cases.

CASE PRESENTATION

In this report, we describe a 17-year-old Iranian girl who took 250 mg of the drug for a suicidal attempt and presented with refractory hypotension and non-cardiogenic pulmonary edema treated successfully with the guidance of invasive hemodynamic parameters.

CONCLUSION

For complicated cases, in addition to supportive care and adjuvant therapy such as high-dose insulin and Intralipid, it is mandatory to utilize advanced hemodynamic monitoring to treat hypotension in severe calcium channel blocker poisoning to guide the treatment.

Investigating Deep Sedation With Intravenous Ketamine in Spontaneous Respiration During Pulsed-Field Ablation

OBJECTIVES

The authors report their experience of a protocol for deep sedation with ketamine in spontaneous respiration during the pulsed-field ablation (PFA) of atrial fibrillation (AF).

DESIGN

Observational, prospective, nonrandomized fashion.

SETTING

Single-center hospitalized patients.

PARTICIPANTS

All consecutive patients undergoing PFA of AF.

INTERVENTIONS

Patients undergoing deep sedation with intravenous ketamine.

MEASUREMENTS AND MAIN RESULTS

The authors' sedation protocol involves the intravenous administration of fentanyl (1.5 µg/kg) and midazolam (2 mg) at low doses before local anesthesia with lidocaine. A ketamine adjunct (1 mg/kg) in 5-minute boluses was injected about 5 minutes before the first PFA delivery. The authors enrolled 117 patients (age = 59 ± 10 y, 74.4% males, body mass index = 27.6 ± 5 kg/m2, fluoroscopy time = 24 ± 14 minutes, skin-to-skin time = 80 ± 40 minutes and PFA LA dwell time = 24 ± 7 minutes). By the end of the procedure, pulmonary vein isolation had been achieved in all patients using PFA alone. The mean time under sedation was 54.9 ± 6 minutes, with 92 patients (79%) being sedated for <1 hour. A satisfactory Ramsay Sedation Scale level before ketamine administration was achieved in all patients, except one (80.3% of the patients with rank 3; 18.4% with rank 2). In all procedures, the satisfaction level was found acceptable by both the patient and the primary operator (satisfactory in 98.2% of cases). All patients achieved a Numeric Rating Scale for Pain ≤3 (none or mild). No major procedure or anesthesia-related complications were reported.

CONCLUSION

The authors' standardized sedation protocol with the administration of drugs with rapid onset and pharmacologic offset at low doses was safe and effective, with an optimal degree of patient and operator satisfaction.

Recent advances in the study of anesthesia-and analgesia-related mechanisms of S-ketamine

Ketamine is a racemic mixture of equal amounts of R-ketamine and S-ketamine and is well known to anesthesiologists for its unique dissociative anesthetic properties. The pharmacological properties of ketamine, namely, its sympathetic excitation, mild respiratory depression, and potent analgesia, are still highly valued in its use as an anesthetic for some patients. In particular, since its advent, S-ketamine has been widely used as an anesthetic in many countries due to its increased affinity for NMDA receptors and its enhanced anesthetic and analgesic effects. However, the anesthetic and analgesic mechanisms of S-ketamine are not fully understood. In addition to antagonizing NMDA receptors, a variety of other receptors or channels may be involved, but there are no relevant mechanistic summaries in the literature. Therefore, the purpose of this paper is to review the mechanisms of action of S-ketamine on relevant receptors and systems in the body that result in its pharmacological properties, such as anesthesia and analgesia, with the aim of providing a reference for its clinical applications and research.

Anesthetic Management of Patients with Dilated Cardiomyopathy Undergoing Noncardiac Surgery

Dilated cardiomyopathy (DCM), a primary myocardial disease, is characterized by dilation of the left or both ventricles and systolic dysfunction with or without congestive heart failure. DCM per se is a well-recognized risk factor for sudden cardiac death and poor surgical outcomes following noncardiac surgery. Surgical trauma/stress represents unique challenges for DCM patient management. Unfortunately, there is a big knowledge gap in managing DCM patients undergoing non-cardiac surgery. Therefore, the aim of our review is to provide basic facts and current advances in DCM, as well as a practical guideline to perioperative care providers, for the management of surgical patients with DCM, who are quite rare compared with the general surgical population. This review summarizes recent advances in the medical management of DCM as well as perioperative assessment and management strategies for DCM patients undergoing noncardiac surgery. Optimal surgical outcomes depend on multiple-disciplinary care to minimize perioperative cardiovascular disturbances.

Can remimazolam be safely used in cardiac tamponade?: A case report

RATIONALE

Remimazolam, a benzodiazepine drug, has recently been developed and is currently used for the induction and maintenance of anesthesia. Remimazolam provides hemodynamic stability during anesthesia induction. However, in patients with cardiac tamponade, it is unclear how hemodynamic stability is maintained during the induction and maintenance of general anesthesia with remimazolam.

PATIENT CONCERNS

An 88-year-old male patient had developed hemopericardium due to penetration of a pigtail catheter into the left ventricle during pericardiocentesis, which was performed to treat massive pericardial effusion.

DIAGNOSES

The patient was diagnosed with acute cardiac tamponade and a hemothorax. Hemopericardium and hemothorax were confirmed on chest radiography and computed tomography performed immediately after pericardiocentesis.

INTERVENTIONS

Decompressive pericardiostomy was performed through a left anterolateral thoracotomy with 1-lung ventilation under general anesthesia. Remimazolam was administered for total intravenous anesthesia.

OUTCOMES

Severe hypotension and bradycardia occurred during the induction of anesthesia with remimazolam (6 mg/kg/hours).

LESSONS

Remimazolam may induce severe hemodynamic instability during induction of general anesthesia in patient with cardiac tamponade.

Sedation strategies for pulsed-field ablation of atrial fibrillation: focus on deep sedation with intravenous ketamine in spontaneous respiration

AIMS

A standardized sedation protocol for pulsed-field ablation (PFA) of atrial fibrillation (AF) through irreversible cellular electroporation has not been well established. We report our experience of a protocol for deep sedation with ketamine in spontaneous respiration during the PFA of AF.

METHODS AND RESULTS

All consecutive patients undergoing PFA for AF at our center were included. Our sedation protocol involves the intravenous administration of fentanyl (1.5 mcg/kg) and midazolam (2 mg) at low doses before local anesthesia with lidocaine. A ketamine adjunct (1 mg/kg) was injected about 5 minutes before the first PFA delivery. We enrolled 66 patients (age = 59 ± 9 years, 78.8% males, body mass index = 28.8 ± 5 kg/m2, fluoroscopy time = 21[15-30] min, skin-to-skin time = 75[60-100] min and PFA LA dwell time = 25[22-28] min). By the end of the procedure, PVI had been achieved in all patients by means of PFA alone. The mean time under sedation was 56.4 ± 6 min, with 50 (76%) patients being sedated for less than 1 hour. A satisfactory Ramsey Sedation Scale level before ketamine infusion was achieved in all patients except one (78.8% of the patients with rank 3; 19.7% with rank 2). In all procedures, the satisfaction level was found to be acceptable by both the patient and the primary operator (Score = 0 in 98.5% of cases). All patients reported none or mild pain. No major procedure or anesthesia-related complications were reported.

CONCLUSION

Our standardized sedation protocol with the administration of drugs with rapid onset and pharmacological offset at low doses was safe and effective, with an optimal degree of patient and operator satisfaction.

CLINICAL TRIAL REGISTRATION

Advanced TecHnologies For SuccEssful AblatioN of AF in Clinical Practice (ATHENA). URL: http://clinicaltrials.gov/Identifier: NCT05617456.

Peri-Intubation Hypoxia After Delayed Versus Rapid Sequence Intubation in Critically Injured Patients on Arrival to Trauma Triage: A Randomized Controlled Trial

BACKGROUND

Critically injured patients who are agitated and delirious on arrival do not allow optimal preoxygenation in the emergency area. We investigated whether the administration of intravenous (IV) ketamine 3 minutes before administration of a muscle relaxant is associated with better oxygen saturation levels while intubating these patients.

METHODS

Two hundred critically injured patients who required definitive airway management on arrival were recruited. The subjects were randomized as delayed sequence intubation (group DSI) or rapid sequence intubation (group RSI). In group DSI, patients received a dissociative dose of ketamine followed by 3 minutes of preoxygenation and paralysis using IV succinylcholine for intubation. In group RSI, a 3-minute preoxygenation was performed before induction and paralysis using the same drugs, as described conventionally. The primary outcome was incidence of peri-intubation hypoxia. Secondary outcomes were first-attempt success rate, use of adjuncts, airway injuries, and hemodynamic parameters.

RESULTS

Peri-intubation hypoxia was significantly lower in group DSI (8 [8%]) compared to group RSI (35 [35%]; P = .001). First-attempt success rate was higher in group DSI (83% vs 69%; P = .02). A significant improvement in mean oxygen saturation levels from baseline values was seen in group DSI only. There was no incidence of hemodynamic instability. There was no statistically significant difference in airway-related adverse events.

CONCLUSIONS

DSI appears promising in critically injured trauma patients who do not allow adequate preoxygenation due to agitation and delirium and require definitive airway on arrival.

Current approaches for the treatment of ketamine-induced cystitis

AIMS

Ketamine is a dissociative anesthetic, historically used in a clinical setting for the induction and maintenance of anesthesia. Ketamine usage can produce undesirable psychological manifestations including hallucinations and long-term psychotomimetic effects. As a results of its fast onset and short period of action, ketamine is widely used as a recreational drug. Chronic abuse of ketamine can lead to significant urinary system complications including ketamine-induced cystitis (KIC). Common side effects of chronic ketamine abuse are urinary pain and discomfort and decreased bladder compliance and voiding pressure. Cessation of ketamine use is associated with improvement of symptoms however the exact pathophysiology of KIC remains unknown, complicating the ability of clinicians to treat this condition.

METHOD

A literature search was performed using the National Center for Biotechnology Information (NCBI) Pubmed database up to May 2021.

RESULTS

Animal models of KIC are necessary to further our understanding of KIC pathophysiology and explore potential treatment options. In all cases, cessation of ketamine use is the first line of treatment and is most effective in managing KIC. In addition to cessation, treatment plans must be tailored to the individual, based on the severity of symptoms and disease progression, and include options such as: oral anti-inflammatories, intravesical treatment and in the most severe cases, surgical intervention.

CONCLUSION

KIC is a painful condition that currently lacks standardized treatment methods. Both animal models of KIC and clinical trials to further elucidate the mechanism of KIC pathophysiology must be explored to create targeted treatment plans.

Anesthetic management of patients with sepsis/septic shock

Sepsis is defined as life-threatening organ dysfunction caused by a dysregulated host response to infection, while septic shock is a subset of sepsis with persistent hypotension requiring vasopressors to maintain a mean arterial pressure (MAP) of ≥65 mmHg and having a serum lactate level of >2 mmol/L, despite adequate volume resuscitation. Sepsis and septic shock are medical emergencies and time-dependent diseases with a high mortality rate for which early identification, early antibiotic therapy, and early source control are paramount for patient outcomes. The patient may require surgical intervention or an invasive procedure aiming to control the source of infection, and the anesthesiologist has a pivotal role in all phases of patient management. During the preoperative assessment, patients should be aware of all possible organ dysfunctions, and the severity of the disease combined with the patient's physiological reserve should be carefully assessed. All possible efforts should be made to optimize conditions before surgery, especially from a hemodynamic point of view. Anesthetic agents may worsen the hemodynamics of shock patients, and the anesthesiologist must know the properties of each anesthetic agent. All possible efforts should be made to maintain organ perfusion supporting hemodynamics with fluids, vasoactive agents, and inotropes if required.

Management of Hemorrhagic Shock: Physiology Approach, Timing and Strategies

Hemorrhagic shock (HS) management is based on a timely, rapid, definitive source control of bleeding/s and on blood loss replacement. Stopping the hemorrhage from progressing from any named and visible vessel is the main stem fundamental praxis of efficacy and effectiveness and an essential, obligatory, life-saving step. Blood loss replacement serves the purpose of preventing ischemia/reperfusion toxemia and optimizing tissue oxygenation and microcirculation dynamics. The "physiological classification of HS" dictates the timely management and suits the 'titrated hypotensive resuscitation' tactics and the 'damage control surgery' strategy. In any hypotensive but not yet critical shock, the body's response to a fluid load test determines the cut-off point between compensation and progression between the time for adopting conservative treatment and preparing for surgery or rushing to the theater for rapid bleeding source control. Up to 20% of the total blood volume is given to refill the unstressed venous return volume. In any critical level of shock where, ab initio, the patient manifests signs indicating critical physiology and impending cardiac arrest or cardiovascular accident, the balance between the life-saving reflexes stretched to the maximum and the insufficient distal perfusion (blood, oxygen, and substrates) remains in a liable and delicate equilibrium, susceptible to any minimal change or interfering variable. In a cardiac arrest by exsanguination, the core of the physiological issue remains the rapid restoration of a sufficient venous return, allowing the heart to pump it back into systemic circulation either by open massage via sternotomy or anterolateral thoracotomy or spontaneously after aorta clamping in the chest or in the abdomen at the epigastrium under extracorporeal resuscitation and induced hypothermia. This is the only way to prevent ischemic damage to the brain and the heart. This is accomplishable rapidly and efficiently only by a direct approach, which is a crush laparotomy if the bleeding is coming from an abdominal +/- lower limb site or rapid sternotomy/anterolateral thoracotomy if the bleeding is coming from a chest +/- upper limbs site. Without first stopping the bleeding and refilling the heart, any further exercise is doomed to failure. Direct source control via laparotomy/thoracotomy, with the concomitant or soon following venous refilling, are the two essential, initial life-saving steps.

Ketamine Attenuates Airway Inflammation via Inducing Inflammatory Cells Apoptosis and Activating Nrf2 Pathway in a Mixed-Granulocytic Murine Asthma Model

Purpose

The use of ketamine, an anesthetic, as a treatment for asthma has been investigated in numerous studies. However, how ketamine affects asthma is unclear. The present study examined the effects of ketamine on a murine model of mixed-granulocytic asthma, and the role of the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway.

Methods

The murine model of mixed-granulocytic asthma was established using ovalbumin (OVA) for sensitization and the combination of OVA and lipopolysaccharides (LPS) for challenge. The main characteristics of asthma, oxidative stress biomarkers, and the expression of the Nrf2 pathway were examined. ML385 was administered to verify the role of the Nrf2 pathway.

Results

Mice in the OVA +LPS group developed asthmatic characteristics, including airway hyperresponsiveness, mixed-granulocytic airway inflammation, mucus overproduction, as well as increased levels of oxidative stress and impaired apoptosis of inflammatory cells. Among the three concentrations, ketamine at 75mg/kg effectively attenuated these asthmatic symptoms, activated the Nrf2 pathway, decreased oxidative stress, and induced apoptosis of eosinophils and neutrophils in bronchoalveolar lavage fluid (BALF) with a reducing level of myeloid cell leukemia 1(Mcl-1). ML385 (an Nrf2 inhibitor) eliminated the protective effects of ketamine on the mixed-granulocytic asthma model.

Conclusion

The study concluded that ketamine reduced oxidative stress and attenuated asthmatic symptoms (neutrophilic airway inflammation) by activating the Nrf2-Keap1 pathway, with 75 mg/kg ketamine showing the best results. Ketamine administration also increased neutrophil and eosinophil apoptosis in BALF, which may contribute to the resolution of inflammation. The use of ketamine as a treatment for asthma may therefore be beneficial.

Advanced interventions in the pre-hospital resuscitation of patients with non-compressible haemorrhage after penetrating injuries

Abstract

Early haemorrhage control and minimizing the time to definitive care have long been the cornerstones of therapy for patients exsanguinating from non-compressible haemorrhage (NCH) after penetrating injuries, as only basic treatment could be provided on scene. However, more recently, advanced on-scene treatments such as the transfusion of blood products, resuscitative thoracotomy (RT) and resuscitative endovascular balloon occlusion of the aorta (REBOA) have become available in a small number of pre-hospital critical care teams. Although these advanced techniques are included in the current traumatic cardiac arrest algorithm of the European Resuscitation Council (ERC), published in 2021, clear guidance on the practical application of these techniques in the pre-hospital setting is scarce. This paper provides a scoping review on how these advanced techniques can be incorporated into practice for the resuscitation of patients exsanguinating from NCH after penetrating injuries, based on available literature and the collective experience of several helicopter emergency medical services (HEMS) across Europe who have introduced these advanced resuscitation interventions into routine practice.

Graphical Abstract

Use of ketamine and xylazine anesthesia in dogs: A retrospective cohort study of 3,413 cases

The information regarding the risk of anesthesia-related death in veterinary medicine is scarce, and little is known about the mortality risk of specific anesthetics. The study conducted during 2019 at University of Sarajevo, Veterinary faculty, aimed to estimate the mortality risk of intermittent injectable ketamine-xylazine anesthesia in dogs and to investigate the potential relationship between mortality rate and anesthesiologists’ experience. Anesthetic records, where ketamine and xylazine combination was used for anesthesia induction and maintenance, were reviewed and divided into two groups: inexperienced (AN1) and experienced anesthesiologists (AN2). Inexperienced anesthesiologists were constantly supervised by experienced ones, whose corrective interventions were recorded. Overall detected mortality rate was 0.15%, with 0.18% and 0.11% in the AN1 and AN2 groups, respectively. A statistically significant difference was not found. Records of the AN1 group revealed interventions of experienced anesthesiologist in 92% of cases. Detected mortality rate was within the values previously established for inhalant anesthesia indicating high safety in usage of investigated protocol, if performed by experienced anesthesiologists. The high percentage of interventions of a senior anesthesiologist suggests that supervised upskilling of inexperienced anesthesiologists before their independent work could result in a better outcome.

Peri-intubation Cardiovascular Collapse in Patients Who Are Critically Ill: Insights from the INTUBE Study

Rationale: Cardiovascular instability/collapse is a common peri-intubation event in patients who are critically ill. Objectives: To identify potentially modifiable variables associated with peri-intubation cardiovascular instability/collapse (i.e., systolic arterial pressure <65 mm Hg [once] or <90 mm Hg for >30 minutes; new/increased vasopressor requirement; fluid bolus >15 ml/kg, or cardiac arrest). Methods: INTUBE (International Observational Study to Understand the Impact and Best Practices of Airway Management In Critically Ill Patients) was a multicenter prospective cohort study of patients who were critically ill and undergoing tracheal intubation in a convenience sample of 197 sites from 29 countries across five continents from October 1, 2018, to July 31, 2019. Measurements and Main Results: A total of 2,760 patients were included in this analysis. Peri-intubation cardiovascular instability/collapse occurred in 1,199 out of 2,760 patients (43.4%). Variables associated with this event were older age (odds ratio [OR], 1.02; 95% confidence interval [CI], 1.02-1.03), higher heart rate (OR, 1.008; 95% CI, 1.004-1.012), lower systolic blood pressure (OR, 0.98; 95% CI, 0.98-0.99), lower oxygen saturation as measured by pulse oximetry/Fi_O2 before induction (OR, 0.998; 95% CI, 0.997-0.999), and the use of propofol as an induction agent (OR, 1.28; 95% CI, 1.05-1.57). Patients with peri-intubation cardiovascular instability/collapse were at a higher risk of ICU mortality with an adjusted OR of 2.47 (95% CI, 1.72-3.55), P < 0.001. The inverse probability of treatment weighting method identified the use of propofol as the only factor independently associated with cardiovascular instability/collapse (OR, 1.23; 95% CI, 1.02-1.49). When administered before induction, vasopressors (OR, 1.33; 95% CI, 0.84-2.11) or fluid boluses (OR, 1.17; 95% CI, 0.96-1.44) did not reduce the incidence of cardiovascular instability/collapse. Conclusions: Peri-intubation cardiovascular instability/collapse was associated with an increased risk of both ICU and 28-day mortality. The use of propofol for induction was identified as a modifiable intervention significantly associated with cardiovascular instability/collapse.Clinical trial registered with clinicaltrials.gov (NCT03616054).

Effect of sedation using Ketamine for primary closure of pediatric facial laceration

Pediatric lacerations are frequently encountered by plastic surgeons in the emergency room. Since pediatric patients cannot cooperate due to the anxiety and pain occurring during the suture procedure, sedation is induced. Since commonly used drugs inducing shallow sedation such as chloral hydrates are insufficient to perform procedures, the need or deep sedation has been increased. In our experience, inducing sedation with ketamine is safe and allows for accurate procedures. A total of 106 pediatric patients aged between 3 months to 5 years who visited the emergency room between August 2020 and January 2021 were included in this study. Of the 106 patients, 54 were sedated using ketamine, and the remaining 52 patients who did not cooperate were operated under local anesthesia, and these were set as the control group. The patients were intravenously injected with ketamine 1.5-2.0 mg/kg ketamine while monitoring the blood oxygen saturation, end-tidal CO2, and other vital signs. The patients were discharged as a complete awakening was confirmed by physicians. The number of patients who received sedation induced by ketamine was 54 and the number of patients who underwent the procedure without sedation was 52. The mean induction time of a single injection was 35.3 ± 11.3 minutes, and that of additional injection was 253.5 ± 54.1 minute. The total procedure time of the ketamine group was 20.3 ± 11.85 minutes, and that of the nonketamine group was 19.31 ± 10.50 minutes (P = .454). No statistically significant differences were found between the 2 groups. The need for sedation during the suture procedure in an emergenc9y room has been arising not only for reducing pain and anxiety, but also for safe and accurate procedures and scar minimization. Based on the parental satisfaction and the safety of the procedure, using ketamine is more effective than other drugs and should be used more actively.

Clinical Uses of Ketamine in Children: A Narrative Review

Ketamine is a phencyclidine derivative that acts as a noncompetitive N-methyl-D-aspartate as well as a glutamate receptor antagonist. It also has other minor mechanisms that contribute to its extensive drug profile. Ketamine is a bronchodilator and maintains normal airway reflexes and, thus, permits spontaneous respiration. This, coupled with the fact that it produces potent analgesia, makes it highly suitable for children.

Despite its many merits, the drug’s side effects, along with its cultural image of being a drug of abuse, a drug used in veterinary medicine, or a “date-rape drug” have sullied its reputation within the armamentarium of medicine. Even though it is widely used in developing countries, its use in Western nations has diminished. We have strived to explore the various clinical uses of ketamine in children through this article. In addition, the article also highlights how some of the fears associated with using the drug are unfounded and provides ways by which the drug’s side effects can be prevented and managed.

Independent risk factors of mortality in patients with sepsis receiving single-dose etomidate as an induction agent during rapid sequence intubation in a large tertiary emergency department in Thailand

BACKGROUND

There is limited evidence regarding factors associated with mortality in septic patients receiving etomidate. This study aimed to determine independent pre-intubation factors predicting 28-day mortality in septic patients receiving single-dose etomidate as an induction agent during rapid sequence intubation (RSI).

METHODS

This single-center retrospective cohort study included intubated septic patients receiving etomidate as an induction agent during RSI in the emergency department of Siriraj hospital, Bangkok, Thailand, between January 1st, 2016 and June 30th, 2020. Pre-intubation characteristics were compared between survivors and non-survivors. Independent risk factors associated with 28-day mortality were identified using the Cox proportional hazards regression model. Association between etomidate dosage and mortality was also determined.

RESULTS

A total of 344 patients, 238 (69%) survivors and 106 (31%) non-survivors, were included in the analyses. The initial Cox hazards model identified a pre-intubation lactate level ≥ 4 mmol/L as an independent factor associated with mortality (adjusted Hazards ratio [aHR] 2.66, 95% confidence interval [CI] 1.55-4.56). After removing lactate level from the model due to limited lactate values in the data, cancer was also predictive of 28-day mortality (aHR 1.83, 95%CI 1.10-3.04), while patients with respiratory infections and underlying chronic lung disease were associated with lower mortality (aHR 0.54, 95%CI 0.37-0.80 and aHR 0.57, 0.33-0.96, respectively). Etomidate dosage was not associated with mortality in our study.

CONCLUSION

In septic patients who received a single dose of etomidate, a pre-intubation lactate level ≥ 4 mmol/L and cancer were associated with increased 28-day mortality, while respiratory infection and underlying chronic lung disease were associated with lower mortality. Physicians may take these factors into consideration when selecting induction agents for septic patients.

Enhanced Fear Memories and Altered Brain Glucose Metabolism (18F-FDG-PET) following Subanesthetic Intravenous Ketamine Infusion in Female Sprague-Dawley Rats

Although women and men are equally likely to receive ketamine following traumatic injury, little is known regarding sex-related differences in the impact of ketamine on traumatic memory. We previously reported that subanesthetic doses of an intravenous (IV) ketamine infusion following fear conditioning impaired fear extinction and altered regional brain glucose metabolism (BGluM) in male rats. Here, we investigated the effects of IV ketamine infusion on fear memory, stress hormone levels, and BGluM in female rats. Adult female Sprague–Dawley rats received a single IV ketamine infusion (0, 2, 10, or 20 mg/kg, over a 2-h period) following auditory fear conditioning (three pairings of tone and footshock). Levels of plasma stress hormones, corticosterone (CORT) and progesterone, were measured after the ketamine infusion. Two days after ketamine infusion, fear memory retrieval, extinction, and renewal were tested over a three-day period. The effects of IV ketamine infusion on BGluM were determined using ¹⁸F-fluoro-deoxyglucose positron emission tomography (¹⁸F-FDG-PET) and computed tomography (CT). The 2 and 10 mg/kg ketamine infusions reduced locomotor activity, while 20 mg/kg infusion produced reduction (first hour) followed by stimulation (second hour) of activity. The 10 and 20 mg/kg ketamine infusions significantly elevated plasma CORT and progesterone levels. All three doses enhanced fear memory retrieval, impaired fear extinction, and enhanced cued fear renewal in female rats. Ketamine infusion produced dose-dependent effects on BGluM in fear- and stress-sensitive brain regions of female rats. The current findings indicate that subanesthetic doses of IV ketamine produce robust effects on the hypothalamic–pituitary–adrenal (HPA) axis and brain energy utilization that may contribute to enhanced fear memory observed in female rats.

Hemodynamics in Helicopter Emergency Medical Services (HEMS) Patients Undergoing Rapid Sequence Intubation With Etomidate or Ketamine

BACKGROUND

Rapid sequence intubation (RSI) is performed by helicopter emergency medical services (HEMS) providers to establish airway control. Common induction agents are etomidate and ketamine, both touted to have relatively stable hemodynamic profiles. Limited data comparing these medications in the air medical setting exist.

OBJECTIVE

Compare administration of ketamine and etomidate on peri-intubation hemodynamics.

METHODS

A retrospective chart review of intubations performed by a HEMS program over 69 months was completed. Heart rate (HR) change, systolic blood pressure (SBP) change, and hypotension with etomidate or ketamine use were measured.

RESULTS

There were 258 patients induced with etomidate and 48 with ketamine. Etomidate patients showed a +1.161% change in HR (SD ± 22.7) and -0.49% change in SBP (SD ± 25.0). Ketamine patients showed a -4.7% change in HR (SD ± 16.7) and 17.2% change in SBP (SD ± 43.4). The p-values for percentage change in HR and SBP between etomidate and ketamine were 0.0830 and 0.0018, respectively. Twenty-five episodes of postadministration hypotension occurred with etomidate, and two with ketamine (p = 0.028).

CONCLUSION

Both ketamine and etomidate are appropriate for intubation of HEMS patients. Ketamine was preferentially selected for hypotensive patients with statistically significant improvement in SBP. Although statistically significant, both ketamine and etomidate had relative low incidences of hypotension.

A retrospective data analysis on the induction medications used in trauma rapid sequence intubations and their effects on outcomes

PURPOSE

Rapid sequence intubation (RSI) in trauma patients is common; however, the induction agents used have been debated. We determined which induction medications were used most frequently for adult trauma RSIs and their associations with hemodynamics and outcomes. We hypothesized that etomidate is the most commonly used induction agent and has similar outcomes to other induction agents.

METHODS

This retrospective review at two U.S. level I trauma centers evaluated adult trauma patients undergoing RSI within 24 h of admission, between 01/01/2016 and 12/31/2017. We compared patient characteristics and outcomes by induction agent. Comparisons on the primary outcome of in-hospital mortality and secondary outcomes of peri-intubation hypotension, hospital and ICU length of stay (LOS), ventilator days, and complications used logistic regression or negative binomial regression. Regression models adjusted for hospital site, age, patient severity measures, and intubation location.

RESULTS

Among 1303 trauma patients undergoing RSI within 24 h of admission, 948 (73%) were intubated in the emergency department (ED) and 325 (25%) in the operating room (OR). The most common induction agents were etomidate (68%), propofol (17%), and ketamine (11%). In-hospital mortality was highest in the etomidate group (25.5%), followed by ketamine (17%), and propofol (1.8%).

CONCLUSION

Etomidate was most commonly used in ED intubations; propofol was most used in the OR. Compared to propofol, patients induced with etomidate had higher mortality and complication rates. Findings should be interpreted with caution given limited generalizability and residual confounding by indication.

Evolving Techniques in RSI: Can the Choice of Induction Agent Matter in Securing a Definitive Airway in Emergency Settings?

How to cite this article: George B, Joachim N. Evolving Techniques in RSI: Can the Choice of Induction Agent Matter in Securing a Definitive Airway in Emergency Settings? Indian J Crit Care Med 2022;26(1):15-17.

A review of the most impactful published pharmacotherapy-pertinent literature of 2019 and 2020 for clinicians caring for patients with thermal or inhalation injury

Keeping abreast with current literature can be challenging, especially for practitioners caring for patients sustaining thermal or inhalation injury. Practitioners caring for patients with thermal injuries publish in a wide variety of journals, which further increases the complexity for those with resource limitations. Pharmacotherapy research continues to be a minority focus in primary literature. This review is a renewal of previous years' work to facilitate extraction and review of the most recent pharmacotherapy-centric studies in patients with thermal and inhalation injury. Sixteen geographically dispersed, board-certified pharmacists participated in the review. A MeSH-based, filtered search returned 1,536 manuscripts over the previous 2-year period. After manual review and exclusions, only 98 (6.4%) manuscripts were determined to have a potential impact on current pharmacotherapy practices and included in the review. A summary of the 10 articles that scored highest are included in the review. Nearly half of the reviewed manuscripts were assessed to lack a significant impact on current practice. Despite an increase in published literature over the previous 2-year review, the focus and quality remain unchanged. There remains a need for investment in well-designed, high impact, pharmacotherapy-pertinent research for patients sustaining thermal or inhalation injuries.

Ketamine versus propofol for rapid sequence induction in trauma patients: a retrospective study

BACKGROUND

Rapid Sequence Induction (RSI) is used for emergency tracheal intubation to minimise the risk of pulmonary aspiration of stomach contents. Ketamine and propofol are two commonly used induction agents for RSI in trauma patients. Yet, no consensus exists on the optimal induction agent for RSI in the trauma population. The aim of this study was to compare 30-day mortality in trauma patients after emergency intubation prehospitally or within 30 min after arrival in the trauma centre using either ketamine or propofol for RSI.

METHODS

In this investigator-initiated, retrospective study we included adult trauma patients emergently intubated with ketamine or propofol registered in the local trauma registry at Rigshospitalet, a tertiary university hospital that hosts a level-1 trauma centre. The primary outcome was 30-day mortality. Secondary outcomes included hospital and Intensive Care Unit length of stay as well as duration of mechanical ventilation. We analysed outcomes using multivariable logistic regression models adjusting for age, sex, injury severity score, shock (systolic blood pressure < 90 mmHg) and Glasgow Coma Scale score before intubation and present results as odds ratios (ORs) with 95% confidence intervals.

RESULTS

From January 1st, 2015 through December 31st, 2019 we identified a total of 548 eligible patients. A total of 228 and 320 patients received ketamine and propofol, respectively. The 30-day mortality for patients receiving ketamine and propofol was 20.2% and 22.8% (P = 0.46), respectively. Adjusted OR for 30-day mortality was 0.98 [0.58-1.66], P = 0.93. We found no significant association between type of induction agent and hospital length of stay, Intensive Care Unit length of stay or duration of mechanical ventilation.

CONCLUSIONS

In this study, trauma patients intubated with ketamine did not have a lower 30-day mortality as compared with propofol.

Effects of ketamine analgesia on cardiorespiratory responses and survival to trauma and hemorrhage in rats

Ketamine is the recommended analgesic on the battlefield for soldiers with hemorrhage, despite a lack of supportive evidence from laboratory or clinical studies. Hence, this study determined the effects of ketamine analgesia on cardiorespiratory responses and survival to moderate (37% blood volume; n = 8/group) or severe hemorrhage (50% blood volume; n = 10/group) after trauma in rats. We used a conscious hemorrhage model with extremity trauma (fibular fracture + soft tissue injury) while measuring mean arterial pressure (MAP), heart rate (HR), and body temperature (T_b) by telemetry, and respiration rate (RR), minute volume (MV), and tidal volume (TV) via whole body plethysmography. Male rats received saline (S) or 5.0 mg/kg ketamine (K) (100 µL/100 g body wt) intra-arterially after trauma and hemorrhage. All rats survived 37% hemorrhage. For 50% hemorrhage, neither survival times [180 min (SD 78) vs. 209 min (SD 66)] nor percent survival (60% vs. 80%) differed between S- and K-treated rats. After 37% hemorrhage, K (compared with S) increased MAP and decreased T_b and MV. After 50% hemorrhage, K (compared with S) increased MAP but decreased HR and MV. K effects on cardiorespiratory function were time dependent, significant but modest, and transient at the analgesic dose given. K effects on T_b were also significant but modest and more prolonged. With the use of this rat model, our data support the use of K as an analgesic in injured, hypovolemic patients.NEW & NOTEWORTHY Ketamine administration at a dose shown to alleviate pain in nonhemorrhaged rats with extremity trauma had only modest and transient effects on multiple aspects of cardiorespiratory function after both moderate (37%) and severe (50%) traumatic hemorrhages. Such effects did not alter survival.

The multiple faces of ketamine in anaesthesia and analgesia

Objective

Ketamine is an anaesthetic agent with a unique dissociative profile and pharmacological effects ranging from the induction and maintenance of anaesthesia to analgesia and sedation, depending on the dose. This article provides information for the clinical use of ketamine in anaesthesia, in both conventional and special circumstances.

Methods

This is a non-systematic review of the literature, through a PubMed search up to February 2021.

Results

With a favourable pharmacokinetic profile, ketamine is used in hospital and prehospital settings for emergency situations. It is suitable for patients with many heart conditions and, unlike other anaesthetics, its potential for cardiorespiratory depression is low. Furthermore, it may be used when venous access is difficult as it may be administered through various routes. Ketamine is the anaesthetic of choice for patients with bronchospasm thanks to its bronchodilatory and anti-inflammatory properties.

Conclusion

With a favourable pharmacokinetic profile, ketamine is used in hospital and prehospital settings for emergency situations and is suitable for patients with many cardiac and respiratory conditions.

Repeated Doses of Ketamine Affect the Infant Rat Urogenital System

Aim

Long-term ketamine use is known to create an interstitial cystitis-like problem in the bladder. It is known that long-term intermittent ketamine is applied to the children receiving radiotherapy for sedation. This study was planned to investigate whether this effect seen in the bladder causes similar changes in the kidneys, testicles, epididymis and ductus deferens.

Materials and Methods

A total of 12 male Wistar Albino rats for 3 weeks were used in the study. Rats were divided equally into 2 groups as, ketamine and saline. 50 mg/kg ketamine was administered intraperitoneally during 21 days to ketamine (K) groups. 1mL/kg saline was administered intraperitoneally during 21 days to saline (S) groups. At the end of 21 days kidney and testicular tissues were taken for biochemical and histopathological evaluations.

Results

Histological assessment of kidney tissue showed that tubule epithelial congestion increased significantly in the ketamine group. Epididymis congestion and distortion in the epididymal gland were found to be different in the ketamine group when testicular tissue was examined. Thiobarbituric acid reactive substances (TBARS) level in testicular and kidney tissue was found to be significantly higher in the ketamine group according to the saline group. Catalase (CAT) enzyme activity was significantly lower in the ketamine group compared to the saline group in both tissues. Paraoxonase-1 (PON-1) enzyme activity was significantly higher in the ketamine group compared to the saline group.

Conclusion

We think that the results we have achieved in this study will provide guidance on ketamine, which is repeated in daily anesthesia applications, especially in radiation oncology. But these findings should be supported by clinical and experimental studies that will be conducted in a more detailed and broad series.

Evaluation and Management of the Physiologically Difficult Airway: Consensus Recommendations From Society for Airway Management

Multiple international airway societies have created guidelines for the management of the difficult airway. In critically ill patients, there are physiologic derangements beyond inadequate airway protection or hypoxemia. These risk factors contribute to the "physiologically difficult airway" and are associated with complications including cardiac arrest and death. Importantly, they are largely absent from international guidelines. Thus, we created management recommendations for the physiologically difficult airway to provide practical guidance for intubation in the critically ill. Through multiple rounds of in-person and telephone conferences, a multidisciplinary working group of 12 airway specialists (Society for Airway Management's Special Projects Committee) over a time period of 3 years (2016-2019) reviewed airway physiology topics in a modified Delphi fashion. Consensus agreement with the following recommendations among working group members was generally high with 80% of statements showing agreement within a 10% range on a sliding scale from 0% to 100%. We limited the scope of this analysis to reflect the resources and systems of care available to out-of-operating room adult airway providers. These recommendations reflect the practical application of physiologic principles to airway management available during the analysis time period.

[Analgesia for trauma patients in emergency medicine]

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

Endotracheal Intubation in the Pharmaceutical-Poisoned Patient: a Narrative Review of the Literature

INTRODUCTION

Endotracheal intubation (ETI) is an essential component of the supportive care provided to the critically ill patient with pharmaceutical poisoning; however, specific nuances surrounding intubation including techniques and complications in the context of pharmaceutical poisoning have not been well elucidated.

DISCUSSION

A search of the available literature on ETI in pharmaceutical-poisoned patients was undertaken using Medline, ERIC, Cochrane database, and PsycINFO using the following MeSH and keyword terms: ("toxicology" OR "poisons" OR "drug overdose" OR "poisoning") AND ("intubation, intratracheal" OR "intubation, endotracheal" OR "airway management" OR "respiration, artificial"). A hand-search was also performed when the literature in the above search required additional conceptual clarification, including using the "Similar Articles" feature of PubMed, along with reviewing articles' reference lists that discussed intubation in the context of a poisoning scenario. Articles with any discussion around the ETI process in the context of a pharmaceutical poisoning were then included. Intubation may be performed in patients poisoned with pharmaceuticals in the context of both single and multiple organ dysfunction including central and peripheral nervous system, pulmonary, or cardiovascular toxicity with hemodynamic instability, or localized effects resulting in mechanical airway obstruction. Certain classes of poisonings may require modifications to the standard rapid sequence induction airway management algorithm.

CONCLUSIONS

ETI is a key component of the supportive care provided to the patient poisoned by a pharmaceutical agent. Clinicians should be aware of the spectrum of toxicities that can necessitate intubation, as well as airway management nuances that are specific to various poisoning presentations.

Ketamine for rapid sequence intubation in adult trauma patients: A retrospective observational study

BACKGROUND

In the trauma population, ketamine is commonly used during rapid sequence induction. However, as ketamine has been associated with important side effects, this study sought to compare in-hospital mortality in trauma patients after induction with ketamine versus other induction agents.

METHODS

We retrospectively identified adult trauma patients intubated in the pre-hospital phase or initially in the trauma bay at two urban level-1 trauma centers during a 2-year period using local trauma registries and medical records. In-hospital mortality was compared for patients intubated with ketamine versus other agents using logistic regression with adjustment for age, gender, Injury Severity Score (ISS), systolic blood pressure (SBP) < 90 mm Hg, and pre-hospital Glasgow Coma Scale (GCS) score.

RESULTS

A total of 343 trauma patients were included with a median ISS of 25 [17-34]. The most frequently used induction agents were ketamine (36%) and propofol (36%) followed by etomidate (9%) and midazolam (5%). There was no difference in ISS or the presence of SBP <90 mm Hg according to the agent of choice, but the pre-hospital GCS score was higher for patients intubated with ketamine (median 8 vs 5, P = .001). The mortality for patients intubated with ketamine was 18% vs 27% for patients intubated with other agents (P = .14). This remained statistically insignificant in the multivariable logistic regression analysis (odds ratio 0.68 [0.33-1.41], P = .30).

CONCLUSIONS

We found no statistically significant difference in mortality among patients intubated in the initial phase post-trauma with the use of ketamine compared with other agents (propofol, etomidate, or midazolam).

Effects of Ketamine on Rodent Fear Memory

Ketamine, a multimodal anesthetic drug, has become increasingly popular in the treatment of pain following traumatic injury as well as treatment-resistant major depressive disorders. However, the psychological impact of this dissociative medication on the development of stress-related disorders such as post-traumatic stress disorder (PTSD) remains controversial. To address these concerns, preclinical studies have investigated the effects of ketamine administration on fear memory and stress-related behaviors in laboratory animals. Despite a well-documented line of research examining the effects of ketamine on fear memory, there is a lack of literature reviews on this important topic. Therefore, this review article summarizes the current preclinical literature on ketamine and fear memory with a particular emphasis on the route, dose, and timing of ketamine administration in rodent fear conditioning studies. Additionally, this review describes the molecular mechanisms by which ketamine may impact fear memory and stress-related behaviors. Overall, findings from previous studies are inconsistent in that fear memory may be increased, decreased, or unaltered following ketamine administration in rodents. These conflicting results can be explained by factors such as the route, dose, and timing of ketamine administration; the interaction between ketamine and stress; and individual variability in the rodent response to ketamine. This review also recommends that future preclinical studies utilize a clinically relevant route of administration and account for biological sex differences to improve translation between preclinical and clinical investigations.

The benefit of adding lidocaine to ketamine during rapid sequence endotracheal intubation in patients with septic shock: A randomised controlled trial

BACKGROUND

Patients with septic shock commonly require endotracheal intubation under general anaesthesia in the operating theatre, the emergency department, and the intensive care unit. Hypotension is a serious complication after induction of general anaesthesia, especially in patients with circulatory failure. No randomised controlled trials had previously investigated protocols for induction of anaesthesia in septic shock patients. The aim of the current work is to compare two protocols, lidocaine-ketamine combination versus ketamine full-dose for rapid-sequence endotracheal intubation in patients with septic shock.

METHODS

Forty-four adult patients, with septic shock, scheduled for emergency surgical intervention were enrolled in this randomised, double-blinded, controlled study. Patients were randomised to receive either 1 mg/kg ketamine (ketamine group, n = 22) or 0.5 mg/kg ketamine plus 1 mg/kg lidocaine (ketamine-lidocaine group, n = 22) for induction of anaesthesia in addition to 0.05 mg/kg midazolam (in both groups). Our primary outcome was the mean arterial pressure (MAP). Other outcomes included frequency of post-induction hypotension, heart rate, and cardiac output.

RESULTS

Forty-three patients were available for final analysis. The average MAP reading in the first 5 min post-induction was higher in ketamine-lidocaine group than in the ketamine group {82.8 ± 5.6 mmHg and 73 ± 10.2 mmHg, P < 0.001}. Furthermore, the incidence of post-intubation hypotension was lower in the ketamine-lidocaine group than in the ketamine group {1 patient (5%) versus 17 patients (77%), P < 0.001}. The ketamine-lidocaine group showed higher MAP in almost all the readings after induction compared to ketamine group. Other haemodynamic variables including cardiac output and heart rate were comparable between both study groups.

CONCLUSION

Lidocaine-ketamine combination showed less incidence of hypotension compared to ketamine full-dose when used for rapid-sequence endotracheal intubation in patients with septic shock. REGISTRATION URL: https://clinicaltrials.gov/ct2/show/NCT03844984?cond=NCT03844984&rank=1.

Placenta accreta spectrum disorders - Peri-operative management: The role of the anaesthetist

The incidence of placenta accreta spectrum (PAS) is increasing and will become more commonly encountered by obstetric anaesthetists in the elective and emergency settings. Significant maternal and neonatal morbidity is associated with these disorders, and hence it is important for anaesthetists to have early involvement in perioperative planning. Major haemorrhage should be anticipated and requires robust perioperative preparation including Patient Blood Management (PBM) and use of intraoperative strategies for haemorrhage management wherever possible. Several institutions have demonstrated good outcomes with regional anaesthesia alone, but the choice of anaesthetic technique requires individualised planning considering patient, anaesthetic and surgical factors. Optimisation of postoperative analgesia needs additional consideration; it is key to good recovery, minimising the impact on quality of life and reducing the risk of persistent post-surgical pain. Further research is required to ascertain the optimal multi-modal analgesic regime including the role of peripheral nerve blockade.

The Influence of Hemorrhagic Shock on the Disposition and Effects of Intravenous Anesthetics: A Narrative Review

The need to reduce the dose of intravenous anesthetic in the setting of hemorrhagic shock is a well-established clinical dogma. Considered collectively,; the body of information concerning the behavior of intravenous anesthetics during hemorrhagic shock, drawn from animal and human data, confirms that clinical dogma and informs the rational selection and administration of intravenous anesthetics in the setting of hemorrhagic shock. The physiologic changes during hemorrhagic shock can alter pharmacokinetics and pharmacodynamics of intravenous anesthetics. Decreased size of the central compartment and central clearance caused by shock physiology lead to an altered dose-concentration relationship. For most agents and adjuncts, shock leads to substantially higher concentrations and increased effect. The notable exception is etomidate, which has relatively unchanged pharmacokinetics during shock. Increased concentrations lead to increased primary effect as well as increased side effects, notably cardiovascular effects. Pharmacokinetic changes are essentially reversed for all agents by fluid resuscitation. Propofol is unique among agents in that, in addition to the pharmacokinetic changes, it exhibits increased potency during shock. The pharmacodynamic changes of propofol persist despite fluid resuscitation. The persistence of these pharmacodynamic changes during shock is unlikely to be due to increased endogenous opiates, but is most likely due to increased fraction of unbound propofol. The stage of shock also appears to influence the pharmacologic changes. The changes are more rapid and pronounced as shock physiology progresses to the uncompensated stage. Although scant, human data corroborate the findings of animal studies. Both the animal and human data inform the rational selection and administration of intravenous anesthetics in the setting of hemorrhagic shock. The well-entrenched clinical dogma that etomidate is a preferred induction agent in patients experiencing hemorrhagic shock is firmly supported by the evidence. Propofol is a poor choice for induction or maintenance of anesthesia in severely bleeding patients, even with resuscitation; this can include emergent trauma cases or scheduled cases that routinely have mild or moderate blood loss.

Impact of a targeted bundle of audit with tailored education and an intubation checklist to improve airway management in the emergency department: an integrated time series analysis

BACKGROUND

Endotracheal intubation (ETI) is a commonly performed but potentially high-risk procedure in the emergency department (ED). Requiring more than one attempt at intubation has been shown to increase adverse events and interventions improving first-attempt success rate should be identified to make ETI in the ED safer. We introduced and examined the effect of a targeted bundle of airway initiatives on first-attempt success and adverse events associated with ETI.

METHODS

This prospective, interventional cohort study was conducted over a 2-year period at an Australian Major Trauma Centre. An online airway registry was established at the inception of the study to collect information related to all intubations. After 6 months, we introduced a bundle of initiatives including monthly audit, monthly airway management education and an airway management checklist. A time series analysis model was used to compare standard practice (ie, first 6 months) to the postintervention period.

RESULTS

There were 526 patients, 369 in the intervention group and 157 in the preintervention comparator group. A total of 573 intubation attempts were performed. There was a significant improvement in first-attempt success rates between preintervention and postintervention groups (88.5% vs 94.6%, relative risk 1.07; 95% CI 1.00 to 1.14, p=0.014). After the introduction of the intervention the first-attempt success rate increased significantly, by 13.4% (p=0.006) in the first month, followed by a significant increase in the monthly trend (relative to the preintervention trend) of 1.71% (p<0.001). The rate of adverse events were similar preintervention and postintervention (hypoxia 8.3% vs 8.9% (p=0.81); hypotension 8.3% vs 7.0% (p=0.62); any complication 27.4% vs 23.6% (p=0.35)).

CONCLUSIONS

This bundle of airway management initiatives was associated with significant improvement in the first-attempt success rate of ETI. The introduction of a regular education programme based on the audit of a dedicated airway registry, combined with a periprocedure checklist is a worthwhile ED quality improvement initiative.

The High-Risk Airway

The high-risk airway is a common presentation and a frequent cause of anxiety for emergency physicians. Preparation and planning are essential to ensure that these challenging situations are managed successfully. Difficult airways typically present as either physiologic or anatomic, each type requiring a specialized approach. Primary physiologic considerations are oxygenation, hemodynamics, and acid-base, whereas anatomic difficulty is overcome using proper positioning and skilled laryngoscopy to ensure success. It is essential to be comfortable performing alternative techniques to address varying presentations. Ultimately, competence in airway management hinges on consistent training, deliberate practice, and a dedication to excellence.

Association of ketamine use with lower risks of post-intubation hypotension in hemodynamically-unstable patients in the emergency department

To determine whether ketamine use for tracheal intubation, compared to other sedative use, is associated with a lower risk of post-intubation hypotension in hemodynamically-unstable patients in the emergency department (ED), we analyzed the data of a prospective, multicenter, observational study-the second Japanese Emergency Airway Network (JEAN-2) Study-from February 2012 through November 2017. The current analysis included adult non-cardiac-arrest ED patients with a pre-intubation shock index of ≥0.9. The primary exposure was ketamine use as a sedative for intubation, with midazolam or propofol use as the reference. The primary outcome was post-intubation hypotension. A total of 977 patients was included in the current analysis. Overall, 24% of patients developed post-intubation hypotension. The ketamine group had a lower risk of post-intubation hypotension compared to the reference group (15% vs 29%, unadjusted odds ratio [OR] 0.45 [95% CI 0.31-0.66] p < 0.001). This association remained significant in the multivariable analysis (adjusted OR 0.43 [95% CI 0.28-0.64] p < 0.001). Likewise, in the propensity-score matching analysis, the patients with ketamine use also had a significantly lower risk of post-intubation hypotension (OR 0.47 [95% CI, 0.31-0.71] P < 0.001). Our observations support ketamine use as a safe sedative agent for intubation in hemodynamically-unstable patients in the ED.

Effects of continuous ketamine infusion on hemodynamics and mortality in critically ill children

We investigated the hemodynamic and mortality effects of continuous ketamine infusion in critically ill pediatric patients. We conducted a retrospective cohort study in a tertiary pediatric intensive care unit (PICU). Patients who used continuous sedative from 2015 to 2017 for 24 hours or more were included. We compared blood pressure, heart and respiratory rates, vasogenic medications, and sedation and pain scores for 12 hours before and after initiation of continuous ketamine. The mortality rates for continuous ketamine and Non-ketamine groups were compared by multivariate logistic regression. A total of 240 patients used continuous sedation, and 82 used continuous ketamine. The median infusion rate of ketamine was 8.1 mcg/kg/min, and the median duration was 6 days. Heart rates (138 vs. 135 beat/minute, P = .033) and respiratory rates (31 vs. 25 respiration/minute, P = .001) decreased, but blood pressure (99.9 vs. 101.1 mm Hg, P = .124) and vasogenic medications did not change after ketamine infusion. Continuous ketamine was not a significant risk factor for mortality (hazard ratio 1.352, confidence interval 0.458–3.996). Continous ketamine could be used in PICU without hemodynamic instability. Further studies in randomized controlled design about the effects of continuous ketamine infusion on hemodynamic changes, sedation, and mortality are required.

Association between intravenous ketamine-induced stress hormone levels and long-term fear memory renewal in Sprague-Dawley rats

Ketamine is a multimodal dissociative anesthetic and analgesic that is widely used after traumatic injury. We previously reported that an analgesic dose of intravenous (IV) ketamine infusion (10 mg/kg, 2-h) after fear conditioning enhanced short-term fear memory in rats. Here, we investigated the effects of the same dose of an IV ketamine infusion on plasma stress hormone levels and long-term fear memory in rats. Adult male Sprague-Dawley rats (9-week-old with an average weight of 308 g upon arrival) received a ketamine infusion (0 or 10 mg/kg, 2-h) immediately after auditory fear conditioning (three auditory tone and footshock [0.6 mA, 1-s] pairings) on Day 0. After the infusion, a blood sample was collected from a jugular vein catheter for corticosterone and progesterone assays, and each animal was tested on tail flick to measure thermal antinociception. One week later, animals were tested on fear extinction acquisition (Day 7), fear extinction retrieval (Day 8), and fear renewal (Day 9). The IV ketamine infusion, compared to the saline infusion, reduced locomotor activity (sedation), increased tail flick latency (antinociception), and elevated plasma corticosterone and progesterone levels. The ketamine infusion did not alter long-term fear memory extinction or fear renewal. However, elevated corticosterone and progesterone levels resulting from the ketamine infusion were correlated with sedation, antinociception, and long-term fear memory renewal. These results suggest that individual differences in sensitivity to acute ketamine may predict vulnerability to develop fear-related disorders.

Use of Survey and Delphi Process to Understand Trauma Anesthesia Care Practices

BACKGROUND

Few trauma guidelines evaluate and recommend anesthesiology practices and there are no trauma anesthesia-specific guidelines. There is no information on how anesthesiologists perceive clinical practice patterns. Our objective was to understand the perceptions of anesthesiologists regarding trauma anesthesia practices.

METHODS

A survey assessing anesthesia management of trauma patients was distributed to 21,491 anesthesiologists. A subset of 10 of these questions was subsequently reviewed by a trauma anesthesiology focus group through a 3-round web-based Delphi process. A question was deemed to have respondent consensus if the response with the highest percentage of agreement was unchanged between rounds 1 and 2.

RESULTS

A total of 2360 anesthesiologists (11% response rate) responded to the survey. Results demonstrated that the practitioners' answers conflicted with existing surgical trauma society recommendations (ie, when to transfuse component therapy), and several areas that lacked any guidelines, resulted in response variability among anesthesiologists where not 1 answer achieved >75% agreement (ie, intubation technique of choice for patients with uncleared cervical spine). Thirteen trauma anesthesiologists participated in round 1 (response rate 100%), and 12 responded in rounds 2 and 3 (response rate 92%) of the Delphi process. None of the questions received 100% agreement. Consensus was achieved on 9 of 10 statements pertaining to trauma anesthesia care. Consensus was not reached on the intubating technique in a hemodynamically unstable patient with an uncleared cervical spine with deficits. Delphi participant opinion conflicted with existing guidelines on 2 statements: the use of cricoid pressure, and when to begin blood component therapy.

CONCLUSIONS

There are several important areas of trauma anesthesia practice where guidelines do not exist and several where existing guidelines are not endorsed by the majority of practitioners who completed our survey. The lack of consensus on trauma anesthesia management and the variation in survey responses demonstrate a need to develop evidence-based trauma anesthesia guidelines.