Intravenous anesthesia for the patient with left ventricular dysfunction

Cardiac Function Decline After General Anesthesia and Cardiac Catheterization in Pediatric Cardiac Transplant Recipients

BACKGROUND

Pediatric cardiac transplant recipients undergo elective cardiac catheterization and endomyocardial biopsy (CC/EMB) for graft dysfunction surveillance often facilitated by general anesthesia (GA). GA and positive pressure ventilation (PPV) also depress cardiac function confounding the graft's functional assessment. We aimed to evaluate the frequency of cardiac function decline, going from the awake to the anesthetized state, and determine its association with anesthetic and patient-related factors.

METHODS

Electronic medical records of pediatric heart transplant recipients undergoing CC/EMB under GA/PPV were retrospectively reviewed. Patients with awake normal cardiac function, assessed by same-day preoperative echocardiographic left ventricular shortening fraction (LVSF) ≥28% were included. A priori, groups were: (1) cardiac function decline (post- catheterization under GA, LVSF< 28%), and (2) no cardiac function decline. Univariate and logistic regression analysis accounting for repeated encounters per patient were performed.

RESULTS

225 eligible encounters occurred in 102 patients. Cardiac function declined in 17.3% (39/225) encounters, and in 25% (26/102) of patients. Logistic regression identified independent predictors as: older age (OR 1.4, 95% CI: 1.1-1.7, P = 0.002), angiotensin-converting enzyme inhibitor (ACEI) use (OR 2.5, 95% CI: 1.2-4.3, P = 0.018), and elevated right ventricular end diastolic pressure (RVEDP) (OR 2.4, 95% CI: 1.1-5.4, P = 0.039), with AUC 0.75. Older age and ACEI use (P = 0.001) and, older age and elevated RVEDP (P = 0.037) were correlated.

CONCLUSIONS

One in 4 patients demonstrated cardiac function decline from the awake to the anesthetized state, occurring most commonly in older children with elevated RVEDP using ACEI. Most cardiac function declines are unrelated to rejection.

Pharmacokinetic-pharmacodynamic Modelling of NH600001 in Healthy Subjects and Patients Undergoing Gastroscopy

NH600001 is a new general anaesthetic drug with a structure similar to etomidate. The objective of this study was to investigate the relationship between concentrations of NH600001 and sedation efficacy based on data from phase I-II studies and factors influencing the pharmacokinetics and pharmacodynamics of NH600001. The dataset consisted of 2 phase I studies in healthy subjects and 1 phase II study in patients undergoing gastroscopy. Nonlinear mixed effects modeling was used in developing the population pharmacokinetics and pharmacodynamics (PopPK/PD) model of NH600001. Three-compartment model was used to describe the PK profile of NH600001. Parameters were used for allometric scaling on body weight, where the exponents were set to 0.75 for clearance and 1 for volumes. Co-administration of alfentanil hydrochloride influenced the distribution volume of the central compartment and clearance. Effect of patients undergoing gastroscopy (compared with healthy subjects) on clearance, the distribution volume of the superficial peripheral compartment and inter-compartmental clearance for deep peripheral compartment and central compartment was included the final PopPK model. The effect compartment model well characterized the PK/PD relationship of NH600001. Simulation results showed that an initial dose of 0.25 mg/kg of NH600001 resulted in rapid sedation, and three additional doses at 5-min intervals could maintain sedation for more than 20 min. A PopPK/PD model was successfully constructed for NH600001 in healthy subjects and in patients undergoing gastroscopy that could inform the dosing regimens of the forthcoming phase III study.

Propofol vs etomidate for induction prior to invasive mechanical ventilation in patients with acute myocardial infarction

BACKGROUND

Patients with acute myocardial infarction (AMI) requiring invasive mechanical ventilation (IMV) have a high mortality. However, little is known regarding the impact of induction agents, used prior to IMV, on clinical outcomes in this population. We assessed for the association between induction agent and mortality in patients with AMI requiring IMV.

METHODS

We compared clinical outcomes between those receiving propofol compared to etomidate for induction among adults with AMI between October 2015 and December 2019 using the Vizient® Clinical Data Base, a multicenter, US national database. We used inverse probability treatment weighting (IPTW) to assess for the association between induction agent and in-hospital mortality.

RESULTS

We identified 5,147 patients, 1,386 (26.9%) of received propofol and 3,761 (73.1%) received etomidate for IMV induction. The mean (SD) age was 66.1 (12.4) years, 33.0% were women, and 51.6% and 39.8% presented with STEMI and cardiogenic shock, respectively. Patients in the propofol group were more likely to require preintubation vasoactive medication and mechanical circulatory support (both, P < .05). Utilization of propofol was associated with lower mortality compared to etomidate (32.3% vs 36.1%, P = .01). After propensity weighting, propofol use remained associated with lower mortality (weighted mean difference -4.7%; 95% confidence interval: -7.6% to -1.8%, P = .002). Total cost, ventilator days, and length of stay were higher in the propofol group (all, P < .001).

CONCLUSIONS

Induction with propofol, compared with etomidate, was associated with lower mortality for patients with AMI requiring IMV. Randomized trials are needed to determine the optimal induction agent for this critically ill patient population.

Efficacy of propofol-supplemented cardioplegia on biomarkers of organ injury in patients having cardiac surgery using cardiopulmonary bypass: A protocol for a randomised controlled study (ProMPT2)

INTRODUCTION

Cardiac surgery with cardiopulmonary bypass and cardioplegic arrest is known to be responsible for ischaemia and reperfusion organ injury. In a previous study, ProMPT, in patients undergoing coronary artery bypass or aortic valve surgery we demonstrated improved cardiac protection when supplementing the cardioplegia solution with propofol (6 mcg/ml). The aim of the ProMPT2 study is to determine whether higher levels of propofol added to the cardioplegia could result in increased cardiac protection.

METHODS AND ANALYSIS

The ProMPT2 study is a multi-centre, parallel, three-group, randomised controlled trial in adults undergoing non-emergency isolated coronary artery bypass graft surgery with cardiopulmonary bypass. A total of 240 patients will be randomised in a 1:1:1 ratio to receive either cardioplegia supplementation with high dose of propofol (12 mcg/ml), low dose of propofol (6 mcg/ml) or placebo (saline). The primary outcome is myocardial injury, assessed by serial measurements of myocardial troponin T up to 48 hours after surgery. Secondary outcomes include biomarkers of renal function (creatinine) and metabolism (lactate).

ETHICS AND DISSEMINATION

The trial received research ethics approval from South Central - Berkshire B Research Ethics Committee and Medicines and Healthcare products Regulatory Agency in September 2018. Any findings will be shared though peer-reviewed publications and presented at international and national meetings. Participants will be informed of results through patient organisations and newsletters.

TRIAL REGISTRATION

ISRCTN15255199. Registered in March 2019.

Impact of artificial intelligence arrhythmia mapping on time to first ablation, procedure duration, and fluoroscopy use

INTRODUCTION

Artificial intelligence (AI) ECG arrhythmia mapping provides arrhythmia source localization using 12-lead ECG data; whether this information impacts procedural efficiency is unknown. We performed a retrospective, case-control study to evaluate the hypothesis that AI ECG mapping may reduce time to ablation, procedural duration, and fluoroscopy.

MATERIALS AND METHODS

Cases in which system output was used were retrospectively enrolled according to IRB-approved protocols at each site. Matched control cases were enrolled in reverse chronological order beginning on the last day for which the technology was unavailable. Controls were matched based upon physician, institution, arrhythmia, and a predetermined complexity rating. Procedural metrics, fluoroscopy data, and clinical outcomes were assessed from time-stamped medical records.

RESULTS

The study group consisted of 28 patients (age 65 ± 11 years, 46% female, left atrial dimension 4.1 ± 0.9 cm, LVEF 50 ± 18%) and was similar to 28 controls. The most common arrhythmia types were atrial fibrillation (n = 10), premature ventricular complexes (n = 8), and ventricular tachycardia (n = 6). Use of the system was associated with a 19.0% reduction in time to ablation (133 ± 48 vs. 165 ± 49 min, p = 0.02), a 22.6% reduction in procedure duration (233 ± 51 vs. 301 ± 83 min, p < 0.001), and a 43.7% reduction in fluoroscopy (18.7 ± 13.3 vs. 33.2 ± 18.0 min, p < 0.001) versus controls. At 6 months follow-up, arrhythmia-free survival was 73.5% in the study group and 63.3% in the control group (p = 0.56).

CONCLUSION

Use of forward-solution AI ECG mapping is associated with reductions in time to first ablation, procedure duration, and fluoroscopy without an adverse impact on procedure outcomes or complications.

Cardioprotective effect of propofol in cardioplegia compared to systemic propofol in heart valves surgery; a randomized controlled trial

Background

Myocardial protection is still a focus of ongoing research. Propofol is used widely during the induction of anaesthesia in cardiac surgery. So, this triggers us to investigate the cardioprotective effect of the propofol when added to the cardioplegia compared to systemic propofol by measuring the troponin T level.

Methods

This clinical randomized controlled trial was carried out on 150 patients operated for elective valvular heart surgery. Patients were assigned into three equal groups: Group 1: received propofol in the cardioplegia, Group 2: received propofol injection in the aortic line before and after the aortic cross-clamp, and Group 3 (control group): patients without propofol in the cardioplegia or aortic line. All patients were subjected to full medical histories, physical examinations, routine tests, and echocardiography. Cardiac troponin T was measured before surgery and 4 times postoperatively.

Results

In group 1, there was a significant improvement in troponin T level at the last reading compared with the control group (mean ± SD. of group 1 was 246.4 ± 131.4, mean ± SD. of group 3 was 317.0 ± 117.9, p = 0.031), denoting propofol's cardioprotective effect when added as a cardioplegia additive. In group 2, there was a significant improvement of troponin T level at the last reading compared with the group 1 and control group (mean ± SD. of group 2 was 202.54 ± 156.03, mean ± SD. of group 3 was 317.0 ± 117.9, p < 0.001), denoting propofol's more cardioprotective effect when used systemically during cardiopulmonary bypass than when added as a cardioplegia additive.

Conclusions

In valvular cardiac surgery, propofol has an additional cardioprotective effect and a superior cardiac outcome when administered systematically during cardiopulmonary bypass rather than added to cardioplegia.

Trial registration

Pan African Clinical Trials Register PACTR201907764652028. Registered on 01 July 2019, retrospectively registered, https://pactr.samrc.ac.za/ TrialDisplay.aspx?TrialID = 5726.

Procedural Sedation in Congenital Heart Disease

Procedural sedation in patients with congenital heart disease (CHD) is associated with significant morbidity and mortality. It is vital for the practitioner to fully understand the complexity of lesions, their hemodynamics, and the impact of medications commonly used for procedural sedation on the stability of systemic vascular resistance and pulmonary flow. According to the literature, we explain the interaction of the systemic vascular resistance and pulmonary flow in such lesions and divide them into five categories outlined in this article: (1) CHDs with left-to-right shunt with normal pulmonary arterial pressure and resistance, (2) CHD with left-to-right shunt and moderate to severe elevation of pulmonary arterial pressure with near-normal pulmonary vascular resistance, (3) CHD with pulmonary flow dependent on systemic vascular resistance, (4) patients with congenital coronary stenosis and coronary anomalies, and 5) aortic obstructive lesions.

Preoperative clinical diagnostic accuracy of heart failure among patients undergoing major noncardiac surgery: a single-centre prospective observational analysis

Background

Reliable diagnosis of heart failure during preoperative evaluation is important for perioperative management and long-term care. We aimed to quantify preoperative heart failure diagnostic accuracy and explore characteristics of patients with heart failure misdiagnoses.

Methods

We performed an observational cohort study of adults undergoing major noncardiac surgery at an academic hospital between 2015 and 2019. A preoperative clinical diagnosis of heart failure was defined using keywords from the history and clinical examination or administrative documentation. Across stratified subsamples of cases with and without clinically diagnosed heart failure, health records were intensively reviewed by an expert panel to develop an adjudicated heart failure reference standard using diagnostic criteria congruent with consensus guidelines. We calculated agreement among experts, and analysed performance of clinically diagnosed heart failure compared with the adjudicated reference standard.

Results

Across 40 555 major noncardiac procedures, a stratified subsample of 511 patients was reviewed by the expert panel. The prevalence of heart failure was 9.1% based on clinically diagnosed compared with 13.3% (95% confidence interval [CI], 10.3-16.2%) estimated by the expert panel. Overall agreement and inter-rater reliability (kappa) among heart failure experts were 95% and 0.79, respectively. Based upon expert adjudication, heart failure was clinically diagnosed with an accuracy of 92.8% (90.6-95.1%), sensitivity 57.4% (53.1-61.7%), specificity 98.3% (97.1-99.4%), positive predictive value 83.5% (80.3-86.8%), and negative predictive value 93.8% (91.7-95.9%).

Conclusions

Limitations exist to the preoperative clinical diagnosis of heart failure, with nearly half of cases undiagnosed preoperatively. Considering the risks of undiagnosed heart failure, efforts to improve preoperative heart failure diagnoses are warranted.

The preclinical pharmacological study of a novel intravenous anesthetic, ET-26 hydrochloride, in aged rats

Background

ET-26 hydrochloride (ET-26HCl) is a novel analogue of etomidate approved for clinical trials. However, all results from recent studies were accomplished in young adult animals. The objective of this study was to evaluate the efficacy and safety of ET-26HCl in aged rats.

Methods

Aged Sprague-Dawley rats were randomly divided into three groups (three males and three females in each group) were given dose of two-fold of median effective dose (ED₅₀) of ET-26HCl, etomidate and propofol: the measurements of loss of the righting reflex (LORR) and cardiovascular and respiratory function after injection at the two-fold dose of the median effective dose were used for evaluation of effectiveness and safety, and the modified adrenocorticotropic hormone-stimulation experiment was used to evaluate the inhibition effect of the drugs on the synthesis of adrenal cortical hormones.

Results

There was no significant difference in the onset time among propofol, etomidate and ET-26HCl. The duration of propofol (850.5 ± 77.4 s) was significantly longer than that caused by etomidate (489.8 ± 77.0 s, p = 0.007) and ET-26HCl (347.3 ± 49.0 s, p = 0.0004). No significant difference was observed in the time to stand and normal activity among drugs. A total of 66.7% of rats in the ET-26HCl group were evaluated to have mild hematuria. Then, etomidate and ET-26HCl had a milder blood pressure inhibition effect than propofol. Apnea was observed in all rats administered propofol and the duration for this side effect was 45.0 ± 9.0 s. For etomidate and ET-26HCl, no apnea was observed. No other clinical signs of side-effect were observed, and no rats died. No significant difference was observed in corticosterone concentrations between ET-26HCl and solvent group. However, rats administered etomidate had lower corticosterone concentrations than those administered ET-26HCl at 15, 30, and 60 min.

Conclusions

Our results indicate ET-26HCl in aged rats is an effective sedative-hypnotic with stable myocardial and respiratory performance and also have mild adrenocortical suppression. Thus, these findings increase the potential for the clinical use of ET-26HCl in the elderly population.

Cardiac arrest during endotracheal intubation of children with systolic dysfunction

This multicenter study aimed to describe peri-intubation cardiac arrest in paediatric cardiac patients with significant (moderate or severe) systolic dysfunction of the systemic ventricle. Intubation data were collected from 4 paediatric cardiac ICUs in the United States (January 2015 - December 2017). Clinician practices during intubation of patients with significant dysfunction were compared to practices during intubation of patients without significant systolic dysfunction. There were 67 intubations in patients with significant systolic dysfunction. Peri-intubation cardiac arrest rate in this population was 14.9% (10/67); peri-intubation mortality was 3%. Majority (6/10; 60%) of the cardiac arrests were classified as pulseless electrical activity. Patients with cardiac arrest upon intubation had a higher serum lactate and lower serum pH than patients without peri-intubation cardiac arrest in the significant systolic dysfunction group.In comparing cardiac ICU patients with significant systolic dysfunction (n = 67) to patients from the same time period with normal ventricular function or mild dysfunction (n = 183), clinicians were less likely to use midazolam (11.9% versus 25.1%; p = 0.03) and more likely to use etomidate (16.4% versus 4.4%; p = 0.002) for intubation. Use of other sedative agents, video laryngoscopy, atropine, inotrope initiation, and consultation of an anaesthesiologist for intubation were not statistically different between the groups.This is the first study to describe the rate of and risk factors for peri-intubation cardiac arrest in paediatric cardiac ICU patients with systolic dysfunction. There was a higher peri-intubation cardiac arrest rate compared to published rates in critically ill children with heart disease and compared to children with significant systolic dysfunction undergoing elective general anaesthesia.

Effects of adding low-dose ketamine to etomidate on serum cortisol levels in critically ill cardiac patients: a randomized clinical trial

BACKGROUND

Etomidate was associated with an inhibition of adrenal steroid synthesis. This study aimed to evaluate the effects of adding low-dose ketamine to etomidate to minimize the decrease in serum cortisol level in critically ill cardiac patients.

METHODS

Sixty adult cardiac patients, ≥ 18 years, who underwent upper endoscopy and Colonoscopy to manage acute anemia in the cardiac intensive care units were enrolled. Patients were randomly divided into two groups: (group (E): n = 30) received etomidate 0.2 mg/kg IV followed by etomidate 0.05 mg/kg IV, and (group (KE): n = 30) received ketamine 0.5 mg/kg IV, then etomidate 0.1 mg/kg IV, followed by etomidate 0.05 mg/kg IV. The primary outcome was Serum cortisol level at 6 h after the procedure.

RESULTS

The mean postoperative cortisol level was significantly lower in group E (295.60 ± 49.218 nmol/L) versus group KE (461.00 ± 67.946 nmol/L), with 95% CI = 351.94 to 404.66; p = 0.000. In addition, the estimated serum cortisol reduction level was also significant between groups; In group E, the estimated cortisol level decreased nearly 53% from 632.40 ± 35.066 nmol/L to 295.60 ± 49.218 nmol/L 6 hours postoperative. While in group KE, the estimated cortisol level decreased only 27% from 639.13 ± 43.035 nmol/L to 461.00 ± 67.946 nmol/L.

CONCLUSIONS

Single-dose ketamine (0.5 mg/kg) was helpful to decrease the total dose of etomidate and hence decreased the percentage of serum cortisol level in such critically ill patients with preservation of patient satisfaction.

TRIAL REGISTRATION

This study is registered on ClinicalTrials.gov ( NCT04857450 ; principal investigator: Mostafa Mohammed Elsaid Elhamamsy; registration date: 23/04/ 2021).

Propofol Protects Myocardium From Ischemia/Reperfusion Injury by Inhibiting Ferroptosis Through the AKT/p53 Signaling Pathway

The molecular mechanism underlying the protective role of propofol against myocardial ischemia/reperfusion (I/R) injury remains poorly understood. Previous studies have shown that ferroptosis is an imperative pathological process in myocardial I/R injury. We hypothesized that propofol prevents myocardial I/R injury by inhibiting ferroptosis via the AKT/p53 signaling pathway. The ferroptosis-inducing agent erastin (E) and AKT inhibitor MK2206 (MK) were used to investigate the role of propofol in myocardial I/R injury. H9C2 cells treated without any reagents, erastin for 24 h, propofol for 1 h before adding erastin were assigned as the control (C), E, and E + P group, respectively. Cell viability, reactive oxygen species (ROS), and the expression of antioxidant enzymes, including ferritin heavy chain 1 (FTH1), cysteine/glutamate transporter (XCT), and glutathione peroxidase 4 (GPX4) in H9C2 cells. Rat hearts from the I/R + P or I/R groups were treated with or without propofol for 20 min before stopping perfusion for 30 min and reperfusion for 60 min. Rat hearts from the I/R + P + MK or I/R + MK groups were treated with or without propofol for 20 min, with a 10-min treatment of MK2206 before stopping perfusion. Myocardial histopathology, mitochondrial structure, iron levels, and antioxidant enzymes expression were assessed. Our results demonstrated that erastin increased H9C2 cell mortality and reduced the expression of antioxidant enzymes. I/R, which reduced the expression of antioxidant enzymes and increased iron or p53 (p < 0.05), boosted myocardium pathological and mitochondrion damage. Propofol inhibited these changes; however, the effects of propofol on I/R injury were antagonized by MK (p < 0.05). In addition, AKT siRNA inhibited the propofol-induced expression of antioxidant enzymes (p < 0.05). Our findings confirm that propofol protects myocardium from I/R injury by inhibiting ferroptosis via the AKT/p53 signal pathway.

Propofol, Ketamine, and Etomidate as Induction Agents for Intubation and Outcomes in Critically Ill Patients: A Retrospective Cohort Study

Propofol, ketamine, and etomidate are common anesthetic agents for induction of anesthesia in the ICU. The choice between these agents is complex and may not depend solely upon severity of illness.

OBJECTIVES

To evaluate the association between the administration of propofol, ketamine, and etomidate and ICU, hospital mortality, and length of stay.

DESIGN SETTING AND PARTICIPANTS

Retrospective single-center cohort study. ICUs in a tertiary medical center, between January 01, 2012, and December 31, 2017. Critically ill adult patients given a single IV anesthetic for intubation.

MAIN OUTCOME AND MEASURES

Primary outcomes were ICU and hospital mortality. Secondary outcomes were ICU- and hospital-free days through 28 days. An inverse probability of treatment weighed approach was used. The propensity score was estimated using a generalized logit model as a function of patient characteristics, admission source, ICU type, readmission status, length of ICU stays prior to intubation, and acute physiology score. Mortality outcomes were assessed with weighted logistic regression and -free days assessed by weighted linear regression with Bonferroni correction for pairwise comparisons.

RESULTS

Of 2,673 patients, 36% received propofol, 30% ketamine and 34% etomidate. Overall ICU and hospital mortality were 19% and 29%, respectively. Patients given ketamine had higher odds of ICU mortality (1.45; [95% CI, 1.07-1.94]; p = 0.015) and patients given etomidate had higher odds of ICU mortality (1.87; 1.40-2.49; p < 0.001), hospital mortality (1.43; 1.09-1.86; p = 0.009), and less ICU-free days (-2.10; -3.21 to -1.00; p < 0.001) than those given propofol. Patients given ketamine and etomidate had similar odds of hospital mortality (1.06; 0.80-1.42; p = 0.761) and similar hospital-free days (0.30; -0.81 to 1.40; p = 0.600).

CONCLUSIONS AND RELEVANCE

Compared with ketamine and etomidate, propofol was associated with better outcome in critically ill patients undergoing anesthesia for intubation. Even after adjusting for severity of illness prior to intubation, residual confounders cannot be excluded.

Potentially Inappropriate Prescriptions in Heart Failure with Reduced Ejection Fraction (PIP-HFrEF)

Heart failure (HF) is a chronic debilitating and potentially life-threatening condition. Heart Failure patients are usually at high risk of polypharmacy and consequently, potentially inappropriate prescribing leading to poor clinical outcomes. Based on the published literature, a comprehensive HF-specific prescribing review tool is compiled to avoid medications that may cause HF or harm HF patients and to optimize the prescribing practice of HF guideline-directed medical therapies. Recommendations are made in line with the last versions of ESC guidelines, ESC position papers, scientific evidence, and experts' opinions.

Anesthesia Protocols used to Create Ischemia Reperfusion Myocardial Infarcts in Swine

The porcine ischemia-reperfusion model is one of the most commonly used for cardiology research and for testing interventions for myocardial regeneration. In creating ischemic reperfusion injury, the anesthetic protocol is important for assuring hemodynamic stability of the animal during the induction of the experimental lesion and may affect its postoperative survival. This paper reviews the many drugs and anesthetic protocols used in recent studies involving porcine models of ischemiareperfusion injury. The paper also summarizes the most important characteristics of some commonly used anesthetic drugs. Literature was selected for inclusion in this review if the authors described the anesthetic protocol used and also reported the mortality rate attributed to the creation of the model. This information is an important consideration because the anesthetic protocol can influence hemodynamic stability during the experimental induction of an acute myocardial infarction, thereby impacting the survival rate and affecting the number of animals needed for each study.

Preclinical Pharmacokinetics Study of a Novel Intravenous Anesthetic ET-26 Hydrochloride

BACKGROUND

ET-26 hydrochloride is a novel intravenous anesthetic, approved for clinical trials, that produces a desirable sedative-hypnotic effect with stable myocardial performance and mild adrenocortical suppression in rats and beagle dogs. The objective of this study was to assess the absorption, distribution, metabolism, and excretion of ET-26 hydrochloride.

METHODS

Hepatocytes from human, monkey, dog, rat, and mouse were used to determine the metabolites of ET-26 hydrochloride. Distribution and excretion were assessed in rats and pharmacokinetic studies were performed in beagle dogs.

RESULTS

The metabolic pathway and proposed structure of metabolites were fully assessed resulting from the biotransformation reactions of hydrolysis, dehydrogenation, demethylation and glucuronic acid conjugation. The main distribution of the drug was in fat (15067 ± 801 ng/ml) and liver (13647 ± 1126 ng/ml), and the kidney was the primary excretion route (4.47%-11.94%). The Cmax after injection with 1.045 mg/kg, 2.09 mg/kg, and 4.18 mg/kg was 1476.5 ± 138.9 ng/ml, 2846.1 ± 223.3 ng/ml, and 6233.3 ± 238.9 ng/ml, respectively. The t1/2 of the drug was similar across dose groups at 74.8 ± 10.8 min to 81.4 ± 4.2 min. The AUC0-t values were 30208.1 ± 2026.5 min*ng/ml, 62712.8 ± 1808.3 min*ng/ml, and 130465.2 ± 7457.4 min*ng/ml, respectively.

CONCLUSION

The metabolic pathway and the proposed structure of metabolites for ET-26 hydrochloride were fully assessed. The majority of distribution for ET-26 hydrochloride occurs in the fat and liver, while the primary route of excretion for ET-26 hydrochloride is through the kidney. In dogs, pharmacokinetic features of ET-26 hydrochloride had a linear relationship with dosage.

Iatrogenic Decompensated Heart Failure

Purpose of Review

To provide an overview of the potential iatrogenic causes of acute decompensated heart failure (AHF) and an evidence-based management strategy to address this.

Recent Findings

As the heart failure (HF) population continues to age and become burdened with greater comorbidities and polypharmacy, patients become more susceptible to the iatrogenic precipitants of HF. The following clinical scenarios are familiar to clinicians, but the sequelae to AHF are often unanticipated: HF medications withdrawn during an intercurrent illness and not restarted, cardiotoxic therapy prescribed for cancer without timely and regular monitoring of left ventricular function, excessive intravenous fluids administered for sepsis or postoperatively, a blood transfusion volume not adjusted for body weight, iatrogenic anaemia that goes unnoticed or an inappropriate type of pacemaker implanted in a patient with underlying left ventricular systolic dysfunction.

Summary

Iatrogenic decompensated HF is a phenomenon that is infrequently documented in the literature but increasingly confronted by clinicians of all specialties. It is associated with a high mortality and morbidity rate. By having greater awareness of these triggers, iatrogenic AHF should be one that is prevented rather than managed when it occurs.

Anesthetic Agents Isoflurane and Propofol Decrease Maximal Ca2+-Activated Force and Thus Contractility in the Failing Myocardium

In the normal heart, frequently used anesthetics such as isoflurane and propofol can reduce inotropy. However, the impact of these agents on the failing myocardium is unclear. Here, we examined whether and how isoflurane and propofol influence cardiac contractility in intact cardiac muscles from rats treated with monocrotaline to induce heart failure. We measured force and intracellular Ca2+ ([Ca2 +]i) in trabeculae from the right ventricles of the rats in the absence or presence of propofol or isoflurane. At low to moderate concentrations, both propofol and isoflurane dose-dependently depressed cardiac force generation in failing trabeculae without altering [Ca2+]i At high doses, propofol (but not isoflurane) also decreased amplitude of [Ca2+]i transients. During steady-state activation, both propofol and isoflurane impaired maximal Ca2+-activated force (Fmax) while increasing the amount of [Ca2+]i required for 50% of maximal activation (Ca50). These events occurred without apparent change in the Hill coefficient, suggesting no impairment of cooperativity. Exposing these same muscles to the anesthetics after fiber skinning resulted in a similar decrement in Fmax and rise in Ca50 but no change in the myofibrillar ATPase-Ca2+ relationship. Thus, our study demonstrates that challenging the failing myocardium with commonly used anesthetic agents such as propofol and isoflurane leads to reduced force development as a result of lowered myofilament responsiveness to Ca2+ SIGNIFICANCE STATEMENT: Commonly used anesthetics such as isoflurane and propofol can impair myocardial contractility in subjects with heart failure by lowering myofilament responsiveness to Ca2+. High doses of propofol can also reduce the overall amplitude of the intracellular Ca2+ transient. These findings may have important implications for the safety and quality of intra- and perioperative care of patients with heart failure and other cardiac disorders.

Sedation strategies for defibrillation threshold testing: safety outcomes with anaesthesiologist compared to proceduralist-directed sedation: an analysis from the SIMPLE study

Aims

No standard practice exists with respect to anaesthesiologist-directed sedation (ADS) vs. sedation by proceduralist (PDS) for defibrillation threshold (DT) testing. We aimed to evaluate adverse events and safety outcomes with ADS vs. PDS for DT testing.

Methods and results

A post hoc analysis of the Shockless Implant Evaluation (SIMPLE) study was performed among the 1242 patients who had DT testing (624 ADS and 618 PDS). We evaluated both intraoperative and in-hospital adverse composite events and two safety composite outcomes at 30-days of the main trial. Propensity score adjusted models were used to compute odds ratio (OR) and 95% confidence interval (CI) to evaluate the association between adverse and safety outcomes with method of sedation and independent predictors for use of ADS. Compared to PDS, patients who received ADS were younger (62 ± 12 years vs. 64 ± 12 years, P = 0.01), had lower ejection fraction (left ventricular ejection fraction 0.31 ± 13 vs. 0.33 ± 13, P = 0.03), were more likely to receive inhalational anaesthesia, propofol, or narcotics (P < 0.001, respectively) and receive an arterial line (43% vs. 8%, P = <0.0001). Independent predictors for ADS sedation were presence of coronary artery disease (OR 1.69, 95% CI 1.0-2.72; P = 0.03) and hypertrophic cardiomyopathy (OR 2.64, 95% CI 1.19-5.85; P = 0.02). Anaesthesiologist directed sedation had higher intraoperative adverse events (2.2% vs. 0.5%; OR 4.47, 95% CI 1.25-16.0; P = 0.02) and higher primary safety outcomes at 30 days (8.2% vs. 4.9%; OR 1.72 95% CI 1.06-2.80; P = 0.03) and no difference in other outcomes compared to PDS.

Conclusion

Proceduralist-directed sedation is safe, however, this could be result of selection bias. Further research is needed.

Etomidate and propylene glycol activate nociceptive TRP ion channels

BACKGROUND

Etomidate is a preferred drug for the induction of general anesthesia in cardiovascular risk patients. As with propofol and other perioperatively used anesthetics, the application of aqueous etomidate formulations causes an intensive burning pain upon injection. Such algogenic properties of etomidate have been attributed to the solubilizer propylene glycol which represents 35% of the solution administered clinically. The aim of this study was to investigate the underlying molecular mechanisms which lead to injection pain of aqueous etomidate formulations.

RESULTS

Activation of the nociceptive transient receptor potential (TRP) ion channels TRPA1 and TRPV1 was studied in a transfected HEK293t cell line by whole-cell voltage clamp recordings of induced inward ion currents. Calcium influx in sensory neurons of wild-type and trp knockout mice was ratiometrically measured by Fura2-AM staining. Stimulated calcitonin gene-related peptide release from mouse sciatic nerves was detected by enzyme immunoassay. Painfulness of different etomidate formulations was tested in a translational human pain model. Etomidate as well as propylene glycol proved to be effective agonists of TRPA1 and TRPV1 ion channels at clinically relevant concentrations. Etomidate consistently activated TRPA1, but there was also evidence for a contribution of TRPV1 in dependence of drug concentration ranges and species specificities. Distinct N-terminal cysteine and lysine residues seemed to mediate gating of TRPA1, although the electrophile scavenger N-acetyl-L-cysteine did not prevent its activation by etomidate. Propylene glycol-induced activation of TRPA1 and TRPV1 appeared independent of the concomitant high osmolarity. Intradermal injections of etomidate as well as propylene glycol evoked severe burning pain in the human pain model that was absent with emulsification of etomidate.

CONCLUSIONS

Data in our study provided evidence that pain upon injection of clinical aqueous etomidate formulations is not an unspecific effect of hyperosmolarity but rather due to a specific action mediated by activated nociceptive TRPA1 and TRPV1 ion channels in sensory neurons.

p38 mitogen-activated protein kinase gene silencing rescues rat hippocampal neurons from ketamine-induced apoptosis: An in vitro study

Ketamine (KTM) is an anesthetic drug with several advantages, including the elevation of cardiac output and blood pressure. However, KTM may also induce the apoptosis of hippocampal neurons. Notably, p38 mitogen-activated protein kinase (p38MAPK) has previously been studied for its role in neuronal injury. Therefore, the present study evaluated the effect of lentivirus-mediated p38MAPK gene silencing on KTM-induced apoptosis of rat hippocampal neurons. Hippocampal neurons were extracted from neonatal Sprague-Dawley rats, and then treated with KTM, p38MAPK-short hairpin RNA or SB203580 (an inhibitor of p38MAPK). Next, the expression levels of p38MAPK and apoptosis-associated genes, including caspase-3, B-cell lymphoma 2 (Bcl-2) and Bcl-2-associated X protein (Bax), were detected. In addition, cell viability and apoptosis were determined using an MTT assay and flow cytometry, respectively. Finally, telomerase activity of hippocampal neurons was detected by ELISA. The results revealed that silencing of p38MAPK in KTM-treated cells decreased the expression levels of p38MAPK, caspase-3 and Bax, and the extent of p38MAPK phosphorylation, while it increased the expression of Bcl-2. Furthermore, silencing p38MAPK promoted cell viability, cell cycle progression and the telomerase activity of hippocampal neurons, and inhibited the apoptosis of hippocampal neurons. Taken together, the results suggested an inhibitory role of lentivirus-mediated p38MAPK gene silencing on KTM-induced apoptosis of rat hippocampal neurons. Thus, p38MAPK gene silencing may serve as a potential target for preventing the KTM-induced apoptosis of hippocampal neurons.

Cardiopulmonary Resuscitation in Infants and Children With Cardiac Disease: A Scientific Statement From the American Heart Association

Cardiac arrest occurs at a higher rate in children with heart disease than in healthy children. Pediatric basic life support and advanced life support guidelines focus on delivering high-quality resuscitation in children with normal hearts. The complexity and variability in pediatric heart disease pose unique challenges during resuscitation. A writing group appointed by the American Heart Association reviewed the literature addressing resuscitation in children with heart disease. MEDLINE and Google Scholar databases were searched from 1966 to 2015, cross-referencing pediatric heart disease with pertinent resuscitation search terms. The American College of Cardiology/American Heart Association classification of recommendations and levels of evidence for practice guidelines were used. The recommendations in this statement concur with the critical components of the 2015 American Heart Association pediatric basic life support and pediatric advanced life support guidelines and are meant to serve as a resuscitation supplement. This statement is meant for caregivers of children with heart disease in the prehospital and in-hospital settings. Understanding the anatomy and physiology of the high-risk pediatric cardiac population will promote early recognition and treatment of decompensation to prevent cardiac arrest, increase survival from cardiac arrest by providing high-quality resuscitations, and improve outcomes with postresuscitation care.

Development and Testing of a Novel Anaesthesia Induction/Ventilation Protocol for Patients With Cardiogenic Shock Complicating Acute Myocardial Infarction

BACKGROUND

Cardiogenic shock is a life-threatening condition and patients might require rapid sequence induction (RSI) and mechanical ventilation. In this study, we evaluated a new RSI/mechanical ventilation protocol in patients with acute myocardial infarction complicated by cardiogenic shock.

METHODS

We included consecutive adult patients who were transferred to the emergency department. The RSI protocol included 5 phases: preoxygenation, pretreatment, induction/paralysis, intubation, and mechanical ventilation (PPIIM). A posteriori, we selected historical patients managed with standard RSI as a control group. The primary outcome was hemodynamic derangement or hypoxemia from enrollment until intensive care unit (ICU) admission.

RESULTS

We studied 31 consecutive patients who were intubated using the PPIIM protocol and 22 historical controls. We found significant differences in systolic (85.32 ± 4.23 vs 71.72 ± 7.98 mm Hg; P < 0.0001), diastolic (58.84 ± 5.84 vs 39.05 ± 5.63 mm Hg; P < 0.0001), and mean arterial pressure (67.71 ± 4.90 vs 49.90 ± 5.66 mm Hg; P < 0.0001), as well as in partial pressure of oxygen (85.80 ± 19.82 vs 164.73 ± 43.07 mm Hg; P < 0.0001) between the PPIIM and control group at 5 minutes of automated ventilation. Also, statistically significant differences were observed in diastolic (59.74 ± 4.93 vs 47.86 ± 11.47 mm Hg; P < 0.0001) and mean arterial pressure (68.65 ± 4.10 vs 60.23 ± 11.67 mm Hg; P < 0.0001), as well as in partial pressure of oxygen (119.84 ± 50.57 vs 179.50 ± 42.17 mm Hg; P < 0.0001), and partial pressure of carbon dioxide (39.81 ± 10.60 vs 31.00 ± 9.30 mm Hg; P = 0.003) between the 2 groups at ICU admission. Compared with the control group, with PPIIM more patients survived to ICU admission (100% vs 77%) and hospital discharge (71% vs 31.8%), as well as at 90 days (51.6% vs 18.2%), and at 180 days (38.7% vs 13.6%).

CONCLUSIONS

The PPIIM protocol allows safe intubation of acute myocardial infarction patients with cardiogenic shock and improves hemodynamic and oxygenation parameters.

Hemodynamic Effects of Connection to Continuous Renal Replacement Therapy in a Pediatric Animal Model

To assess the hemodynamic effects of connection to continuous renal replacement therapy (CRRT) in a pediatric experimental animal model. Prospective experimental study was performed using piglets between 2 and 3 months of age and 9-11 kg. CRRT with a Prismaflex^R monitor and HF20 filter (surface of 0.2 m² ) was started after monitoring and anesthetic induction with an initial blood flow at 20 mL/min with 10 mL/min increases every minute until the goal flow of 5 mL/kg/min was achieved. Heart rate, blood pressure, central venous pressure, cardiac index, and renal blood flow were registered at baseline, 5, 15, 30, 60, 120, 180, 240, and 360 min. IBM SPSS Statistics 20.0 package was used for analysis. A P value of <0.05 was considered statistically significant. Thirty-four piglets were studied. Blood pressure, cardiac output, and systemic vascular resistance significantly decreased 5-min after CRRT connection (mean arterial pressure from 85.5 to 70.8 mm Hg, P < 0.001, cardiac index from 3.6 to 3.3 L/min/m² P = 0.024, and systemic vascular resistance index from 1759 to 1607 dyn.s/cm⁵ P = 0.012). No significant changes were found in renal blood flow or central venous pressure. All parameters gradually increased at 15 and 30 min after connection but complete recovery was never achieved. Connection to CRRT produces a significant decrease in arterial pressure, cardiac index, and peripheral vascular resistances in hemodynamically stable piglets.

Aortopulmonary collateral flow quantification by MR at rest and during continuous submaximal exercise in patients with total cavopulmonary connection

BACKGROUND

Aortopulmonary collateral flow is considered to have significant impact on the outcome of patients with single ventricle circulation and total cavopulmonary connection (TCPC). There is little information on collateral flow during exercise.

PURPOSE

To quantify aortopulmonary collateral flow at rest and during continuous submaximal exercise in clinical patients doing well with TCPC.

STUDY TYPE

Prospective, case controlled.

POPULATION

Thirteen patients with TCPC (17 (11-37) years) and 13 age and sex-matched healthy controls (18 (11-38) years).

FIELD STRENGTH

1.5T; free breathing; phase sensitive gradient echo sequence.

ASSESSMENT

Blood flow in the ascending and descending aorta and superior vena cava were measured at rest and during continuous submaximal physical exercise in patients and controls. Systemic blood flow (Q_s ) was assumed to be represented by the sum of flow in the superior caval vein (Q_svc ) and the descending aorta (Q_AoD ) at the diaphragm level. Aortopulmonary collateral flow (Q_coll ) was calculated by subtracting Q_s from flow in the ascending aorta (Q_AoA ).

STATISTICS

Mann-Whitney U-test and Wilcoxon test for comparison between groups and between rest and exercise.

RESULTS

Absolute collateral flow in TCPC patients at rest was 0.4 l/min/m² (-0.1-1.2), corresponding to 14% (-2-42) of Q_s . Collateral flow did not change during exercise (difference -0.01 (-0.7-1.0) l/min/m² , P = 0.97). TCPC patients had significantly lower Q_s at rest (2.5 (1.6-4.1) vs. 3.5 (2.6-4.8) l/min/m² , P = 0.001) and during submaximal exercise (3.2 (2.0-6.0) vs. 4.8 (3.3-6.9) l/min/m² , P = 0.001), compared to healthy controls. The increase in Q_s with exercise was also significantly lower in patients than in healthy controls (median 0.6 vs. 1.2 l/min/m² , P < 0.02).

DATA CONCLUSION

Clinical patients doing well with TCPC have significant aortopulmonary collateral flow at rest (14% of Q_s ) compared to healthy controls, which does not change during submaximal exercise.

LEVEL OF EVIDENCE

2 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2018;47:1509-1516.

A randomized clinical trial comparing hemodynamic responses to ketamine-propofol combination (ketofol) versus etomidate during anesthesia induction in patients with left ventricular dysfunction undergoing coronary artery bypass graft surgery

INTRODUCTION

Anesthesia induction is often accompanied by a period of hemodynamic instability, which could be a significant problem in patients with compromised ventricular function. The aim of this study is to compare the hemodynamic responses to etomidate versus a combination of ketamine and propofol (ketofol) for anesthetic induction in patients with left ventricular dysfunction undergoing coronary artery bypass graft (CABG) surgery.

MATERIAL AND METHODS

In a double-blind randomized clinical study, a total of 84 patients with ischemic left ventricular dysfunction (EF < 40%) were randomly assigned to two groups (A and B). Patients in group A received etomidate 0.2 mg/kg and a placebo (normal saline); group B received a combination of ketamine (1 mg/kg) and propofol (1.5 mg/kg) at the induction of anesthesia. Two minutes after induction, hemodynamic variables, including systolic, diastolic, mean arterial pressure (SAP, DAP, MAP) and heart rate (HR), were measured immediately before and after the laryngoscopy, and before intubation and post-intubation at 1, 2, and 3 min.

RESULTS

The decrease in all hemodynamic parameters (SBP, DBP, MAP and HR) from induction time to laryngoscopy was greater in the ketofol group (group B) than in the etomidate group (group A) (p < 0.05). The ephedrine prescription rate due to hemodynamic changes was 24.4% (10 patients) and 5% (2 patients) in group B and group A, respectively (p = 0.03).

CONCLUSIONS

We found that etomidate provides superior hemodynamic stability as compared to ketofol in patients with left ventricular dysfunction undergoing CABG surgery under general anesthesia.

Cardiac Radionuclide Imaging in Rodents: A Review of Methods, Results, and Factors at Play

The interest around small-animal cardiac radionuclide imaging is growing as rodent models can be manipulated to allow the simulation of human diseases. In addition to new radiopharmaceuticals testing, often researchers apply well-established probes to animal models, to follow the evolution of the target disease. This reverse translation of standard radiopharmaceuticals to rodent models is complicated by technical shortcomings and by obvious differences between human and rodent cardiac physiology. In addition, radionuclide studies involving small animals are affected by several extrinsic variables, such as the choice of anesthetic. In this paper, we review the major cardiac features that can be studied with classical single-photon and positron-emitting radiopharmaceuticals, namely, cardiac function, perfusion and metabolism, as well as the results and pitfalls of small-animal radionuclide imaging techniques. In addition, we provide a concise guide to the understanding of the most frequently used anesthetics such as ketamine/xylazine, isoflurane, and pentobarbital. We address in particular their mechanisms of action and the potential effects on radionuclide imaging. Indeed, cardiac function, perfusion, and metabolism can all be significantly affected by varying anesthetics and animal handling conditions.

Editor's Choice-The cardiovascular implications of sedatives in the cardiac intensive care unit

Patients admitted to the cardiac intensive care unit frequently develop multi-organ system dysfunction associated with their cardiac disease. In many cases, invasive mechanical ventilation is required, which often necessitates sedation for patient-ventilator synchrony, reduction of work of breathing, and patient comfort. In this paper, we describe the use of common sedatives available in the endotracheally intubated critically ill patient and emphasize the clinical and cardiovascular effects. We review γ-aminobutyric acid agonists such as etomidate, benzodiazepines, and propofol, the centrally acting α₂-agonist dexmedetomidine, and the N-methyl-D-aspartate receptor antagonist ketamine. Additionally, we outline the use of opioids and their role in potentiating other sedatives. We note that some sedatives are associated with increased delirium rates, and emphasize that judicious strategies minimizing sedative use are associated with decreases in morbidity and mortality. We also discuss standardized sedation assessment scales and highlight the importance of sedation weaning. Finally, we offer recommendations for sedation use during therapeutic hypothermia, and discuss the use of adjuvant neuromuscular blocking agents.

Metabolite-inactive etomidate analogues alleviating suppression on adrenal function in Beagle dogs

Owing to rapid generation in body, the metabolites of etomidate softdrug are able to accumulate in either the brain or periphery and subsequently affect the recovery from anaesthesia or cause corticosteroid suppression. This study was designed to investigate the ability of two etomidate analogues (ET-26, ET-42) with inactive metabolites to provide anaesthesia with lesser corticosteroid suppression. The 50% effective dose (ED₅₀) of ET-26, ET-42, Etomidate, MOC-ET (an etomidate softdrug) and CPMM (an improved etomidate softdrug) required to induce anaesthesia intravenously in Beagle dogs were 1.44mg/kg, 0.72mg/kg, 0.43mg/kg 23.12mg/kg and 0.59mg/kg, respectively. After adrenocorticotropic hormone (ACTH) stimulation, the serum concentrations of cortisol and corticosterone in the ET-26, ET-42 and CPMM groups were similar to those of controls, and significantly higher than those of the etomidate and MOC-etomidate groups (P<0.05). Furthermore, no significant differences in serum concentrations of cortisol and corticosterone after ACTH-stimulation between ET-26, ET-42, CPMM, and blank control groups were observed. In this study, anaesthetic potencies of ET-26 (ED₅₀=1.44mg/kg) and ET-42 (ED₅₀=0.72mg/kg) were determined. Both analogues can significantly reduce the corticosteroid suppression in vivo. Metabolite-inactive etomidate derivatives with slow metabolism might provide a novel strategy to improve Etomidate associated corticosteroid suppression.

A Model of Cardiac Remodeling Through Constriction of the Abdominal Aorta in Rats

Heart failure is one of the leading causes of death worldwide. It is a complex clinical syndromethat includes fatigue, dyspnea, exercise intolerance, and fluid retention. Changes in myocardial structure, electrical conduction, and energy metabolism develop with heart failure, leading to contractile dysfunction, increased risk of arrhythmias, and sudden death. Hypertensive heart disease is one of the key contributing factors of cardiac remodeling associated with heart failure. The most commonly-used animal model mimicking hypertensive heart disease is created via surgical interventions, such as by narrowing the aorta. Abdominal aortic constriction is a useful experimental technique to induce a pressure overload, which leads to heart failure. The surgery can be easily performed, without the need for chest opening or mechanical ventilation. Abdominal aortic constriction-induced cardiac pathology progresses gradually, making this model relevant to clinical hypertensive heart failure. Cardiac injury and remodeling can be observed 10 weeks after the surgery. The method described here provides a simple and effective approach to produce a hypertensive heart disease animal model that is suitable for studying disease mechanisms and for testing novel therapeutics.

Drugs That May Cause or Exacerbate Heart Failure: A Scientific Statement From the American Heart Association

Heart failure is a common, costly, and debilitating syndrome that is associated with a highly complex drug regimen, a large number of comorbidities, and a large and often disparate number of healthcare providers. All of these factors conspire to increase the risk of heart failure exacerbation by direct myocardial toxicity, drug-drug interactions, or both. This scientific statement is designed to serve as a comprehensive and accessible source of drugs that may cause or exacerbate heart failure to assist healthcare providers in improving the quality of care for these patients.

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.

Propofol administration to the fetal-maternal unit reduces cardiac oxidative stress in preterm lambs subjected to prenatal asphyxia and cardiac arrest

BACKGROUND

Little is known about the effects of propofol on oxidative stress and its effect on key structures of the contractile apparatus as the myosin light chain 2 (MLC2) and the p38MAPK survival pathway in the preterm heart. We hypothesized that propofol administration could attenuate the hypoxic myocardial injury after birth asphyxia.

METHODS

Pregnant ewes were randomized to receive either propofol or isoflurane anesthesia. A total of 44 late-preterm lambs were subjected to in utero umbilical cord occlusion (UCO), resulting in asphyxia and cardiac arrest, or sham treatment. After emergency cesarean delivery, each fetus was resuscitated, mechanically ventilated, and supported under anesthesia for 8 h using the same anesthetic as the one received by its mother.

RESULTS

At 8 h after UCO, occurrence of reactive oxygen species and activation of inducible nitric oxide synthase in the heart were lower in association with propofol anesthesia than with isoflurane. This was accompanied by less degradation of MLC2 but higher p38MAPK level and in echocardiography with a trend toward a higher median left ventricular fractional shortening.

CONCLUSION

The use of propofol resulted in less oxidative stress and was associated with less cytoskeletal damage of the contractile apparatus than the use of isoflurane anesthesia.

Effects of continuous infusion of etomidate at various dose rates on adrenal function in dogs

BACKGROUND

Etomidate is a commonly used sedative in intravenous anesthesia. The aim of this study was to compare the effects of various etomidate doses administered by continuous infusion on adrenal function in dogs under general anesthesia.

METHODS

Thirty-six healthy adult male dogs were randomly divided into six groups. Sodium pentobarbital alone was administered to the control group (group C); five experimental groups (E1, E2, E3, E4, and E5) were also given etomidate at doses of 10, 15, 20, 25, and 30 μg · kg(-1) · min(-1), respectively, to maintain anesthesia. Heart rate (HR), mean arterial pressure (MAP), and bispectral index (BIS) were monitored. Serum cortisol, aldosterone, adrenaline, and noradrenaline levels were measured, and HR, MAP, and BIS values recorded, before intubation (T0), and at 1 h, 2 h, and 3 h after intubation (T1-3).

RESULTS

Cortisol and aldosterone levels in groups E1-5 decreased as the doses and times of continuous infusion of etomidate increased. The cortisol level was significantly decreased compared with baseline at T3 in group E1 and at T1-3 in groups E2-5 (P < 0.05). Compared with the corresponding levels in group C, cortisol levels were significantly lower than T0 values at T3 in group E1 and at T1-3 in groups E2-5 (P < 0.05). The aldosterone level was significantly lower at T3 in group E2 and at T1-3 in groups E3-5 (P < 0.05). Significant reductions in cortisol levels at T2-3 in group E2 and at T1-3 in groups E3-5 compared with group C were also observed (P < 0.05). The plasma adrenaline and noradrenaline levels, HR, MAP, and BIS in groups E1-5 were within the normal range at the different times and with the different doses (P > 0.05).

CONCLUSIONS

Cortisol and aldosterone levels decreased with time and continuous infusion of etomidate; there were no significant changes in adrenaline and noradrenaline levels, HR, MAP, and BIS in any group.

Hemodynamic response to ketamine in children with pulmonary hypertension

BACKGROUND

The safety of ketamine in children with pulmonary hypertension has been debated because of conflicting results of prior studies in which changes in mean pulmonary artery pressure (mPAP) and pulmonary vascular resistance (PVR) have been widely variable. The goal of this prospective study was to quantitate the effects of ketamine on pulmonary hemodynamics in a cohort of children with pulmonary hypertension under conditions in which variables such as airway/ventilatory management, FiO(2), and use of vasodilating anesthetics were controlled.

METHODS

The IRB approved this study of 34 children undergoing cardiac catheterization for pulmonary hypertension studies. Following anesthetic induction with sevoflurane and tracheal intubation facilitated by the administration of rocuronium 0.7-1 mg·kg(-1) iv, sevoflurane was discontinued and anesthesia was maintained with midazolam 0.1 mg·kg(-1) iv (or 0.5 mg·kg(-1) po preoperatively) and remifentanil iv infusion 0.5-0.7 mcg·kg(-1) ·min(-1). Ventilation was mechanically controlled to maintain PaCO(2) 35-40 mmHg. When endtidal sevoflurane was 0% and FiO(2) was 0.21, baseline heart rate (HR), mean arterial pressure (MAP), mPAP, right atrial pressure (RAP), pulmonary artery occlusion pressure (PAOP), right ventricular end-diastolic pressure (RVEDP), cardiac output, and arterial blood gases were measured, and indexed systemic vascular resistance (SVRI), indexed pulmonary vascular resistance (PVRI), and cardiac index (CI) were calculated. Each child then received a bolus of ketamine 2 mg·kg(-1) infused over 2 min. Measurements and calculations were repeated 2 min after the conclusion of the infusion.

RESULTS

The mean (95% CI) increase in mPAP following ketamine was 2 mmHg (0.2, 3.7), which was statistically significant but clinically insignificant. PVRI and PVRI/SVRI did not change significantly. Hemodynamic changes did not differ among subjects with differing severity of pulmonary hypertension or between subjects chronically treated with pulmonary vasodilators or not.

CONCLUSION

Ketamine is associated with minimal, clinically insignificant hemodynamic changes in sedated, mechanically ventilated children with pulmonary hypertension.

Hemodynamic Responses to Two Different Anesthesia Regimens in Compromised Left Ventricular Function Patients Undergoing Coronary Artery Bypass Graft Surgery: Etomidate-Midazolam Versus Propofol-Ketamine

Background:

Various methods have been suggested to prevent hemodynamic instability caused by propofol and adverse effects caused by etomidate induction. The current study evaluated hemodynamic effects of propofol-ketamine mixture in comparison to etomidate-midazolam mixture during anesthesia induction.

Objectives:

The aim of this study was to evaluate the hemodynamic effects of etomidate-midazolam by comparing it with propofol-ketamine for the induction of anesthesia in patients with left ventricular dysfunction undergoing coronary artery bypass graft surgery.

Patients and Methods:

One-hundred patients aged between 40 and 65 with coronary artery disease and low ejection fraction scheduled for elective coronary artery bypass surgery participated in this study. The patients were randomly allotted to one of the two groups to receive either propofol-ketamine or etomidate-midazolam combination. Two groups were compared for pain on injection and myoclonus, Heart Rate (HR), Systolic Blood Pressure (SBP), Diastolic Blood Pressure (DBP), Mean Arterial Pressure (MAP), Cardiac Index (CI) and Systemic Vascular Resistance (SVR), before and one minute after induction of anesthesia, and one, three and five minutes after intubation.

Results:

Incidence of pain on injection (2 - 4%) and myoclonus (10%) was less in both groups. The hemodynamic response was similar in the two groups for all variables over the time interval, except for CI at one and three minutes after intubation (P = 0.024 and P = 0.048, respectively), and SVR in five minutes after intubation (P = 0.009), with differences being statistically significant.

Conclusions:

Both anesthetic regimens were acceptable for induction in patients with coronary artery disease and left ventricular dysfunction undergoing coronary artery bypass graft surgery.

Current medication practice and tracheal intubation safety outcomes from a prospective multicenter observational cohort study

OBJECTIVES

Tracheal intubation in PICUs is often associated with adverse tracheal intubation-associated events. There is a paucity of data regarding medication selection for safe tracheal intubations in PICUs. Our primary objective was to evaluate the association of medication selection on specific tracheal intubation-associated events across PICUs.

DESIGN

Prospective observational cohort study.

SETTING

Nineteen PICUs in North America.

SUBJECTS

Critically ill children requiring tracheal intubation.

INTERVENTIONS

None.

MEASUREMENT AND MAIN RESULTS

Using the National Emergency Airway Registry for Children, tracheal intubation quality improvement data were prospectively collected from July 2010 to March 2013. Patient, provider, and practice characteristics including medications and dosages were collected. Adverse tracheal intubation-associated events were defined a priori. A total of 3,366 primary tracheal intubations were reported. Adverse tracheal intubation-associated events occurred in 593 tracheal intubations (18%). Fentanyl and midazolam were the most commonly used induction medications (64% and 58%, respectively). Neuromuscular blockade was used in 92% of tracheal intubation with the majority using rocuronium (64%) followed by vecuronium (20%). Etomidate and succinylcholine were rarely used (1.6% and 0.7%, respectively). Vagolytics were administered in 37% of tracheal intubations (51% in infants; 28% in > 1 yr old; p < 0.001). Ketamine was used in 27% of tracheal intubations but more often for tracheal intubations in patients with unstable hemodynamics (39% vs 25%; p < 0.001). However, ketamine use was not associated with lower prevalence of new hypotension (ketamine 8% vs no ketamine 14%; p = 0.08).

CONCLUSIONS

In this large, pediatric multicenter registry, fentanyl, midazolam, and ketamine were the most commonly used induction agents, and the majority of tracheal intubations involved neuromuscular blockade. Ketamine use was not associated with lower prevalence of hypotension.

Propofol protects the immature rabbit heart against ischemia and reperfusion injury: impact on functional recovery and histopathological changes

The general anesthetic propofol protects the adult heart against ischemia and reperfusion injury; however, its efficacy has not been investigated in the immature heart. This work, for the first time, investigates the cardioprotective efficacy of propofol at clinically relevant concentrations in the immature heart. Langendorff perfused rabbit hearts (7–12 days old) were exposed to 30 minutes' global normothermic ischemia followed by 40 minutes' reperfusion. Left ventricular developed pressure (LVDP) and coronary flow were monitored throughout. Lactate release into coronary effluent was measured during reperfusion. Microscopic examinations of the myocardium were monitored at the end of reperfusion. Hearts were perfused with different propofol concentrations (1, 2, 4, and 10 μg/mL) or with cyclosporine A, prior to ischemic arrest and for 20 minutes during reperfusion. Propofol at 4 and 10 μg/mL caused a significant depression in LVDP prior to ischemia. Propofol at 2 μg/mL conferred significant and maximal protection with no protection at 10 μg/mL. This protection was associated with improved recovery in coronary flow, reduced lactate release, and preservation of cardiomyocyte ultrastructure. The efficacy of propofol at 2 μg/mL was similar to the effect of cyclosporine A. In conclusion, propofol at a clinically relevant concentration is cardioprotective in the immature heart.

Anesthetic Drugs in Congenital Heart Disease

The structural defects associated with the various forms of congenital heart disease lead to pathological and functional changes that place patients at risk for adverse events, and in fact the perioperative incidence of morbidity and mortality has been documented to be increased in children with congenital heart disease. Patients with congenital heart disease can present to the anesthesiologist in a relatively precarious state of balance of several hemodynamic factors, including preload, ventricular contractility, systemic vascular resistance, pulmonary vascular resistance, heart rate, and cardiac rhythm. Anesthetic drugs can affect each of these, and an ideal anesthetic drug for such patients does not exist. The purpose of this article is to review the hemodynamic effects of anesthetic drugs and how they may contribute to the occurrence of adverse events in children with congenital heart disease.

Comparison of the impact of the anesthesia induction using thiopental and propofol on cardiac function for non-cardiac surgery

Background

Thiopental and propofol have been widely used for general anesthesia induction, but their impacts on cardiac function have not been well described. A recent study speculated that anesthesia induction using propofol 2 mg/kg transiently reduced left ventricular (LV) contraction by analyzing tissue Doppler-derived imaging (TDI) during induction phase. The purpose of this study was to analyze and to compare the impacts of propofol- and thiopental-induction on LV function.

Methods

Twenty-four female patients with normal LV function undergoing non-cardiac surgery were randomly administered intravenous bolus thiopental (5 mg/kg, Thiopental-group, n = 12) or propofol (2 mg/kg, Propofol-group, n = 12) for anesthesia-induction. TDI of septal mitral annular velocity during systole (S'), early diastole (e') and atrial contraction (a') were determined by transthoracic echocardiography before and 1, 3, and 5 minutes after thiopental/propofol administration (T0, T1, T2, and T3, respectively).

Results

The bispectral index and systolic blood pressure declined significantly during anesthesia induction in both groups, however, more depressed in Thiopental-group compared with those in Propofol-group at T2 and T3 (all, p < 0.05). Among TDI two parameters demonstrated a significant inter-group difference: the S' in propofol was lower than that in Thiopental-group at T3 (p = 0.002), and a' velocities were persistently lower in Propofol-group, compared with same time values in Thiopental-group (T1, T2, and T3: p = 0.025, 0.007, and 0.009, respectively).

Conclusion

Anesthesia induction using propofol revealed a more persistent and profound decline of LV and atrial contraction than that using thiopental. Further studies are needed to understand the clinical implication.

Rapid-sequence intubation: a review of the process and considerations when choosing medications

OBJECTIVE

To summarize published data regarding the steps of rapid-sequence intubation (RSI); review premedications, induction agents, neuromuscular blockers (NMB), and studies supporting use or avoidance; and discuss the benefits and deficits of combinations of induction agents and NMBs used when drug shortages occur.

DATA SOURCE

A search of Medline databases (1966-October 2013) was conducted.

STUDY SELECTION AND DATA EXTRACTION

Databases were searched using the terms rapid-sequence intubation, fentanyl, midazolam, atropine, lidocaine, phenylephrine, ketamine, propofol, etomidate thiopental, succinylcholine, vecuronium, atracurium, and rocuronium. Citations from publications were reviewed for additional references.

DATA SYNTHESIS

Data were reviewed to support the use or avoidance of premedications, induction agents, and paralytics and combinations to consider when drug shortages occur.

CONCLUSIONS

RSI is used to secure a definitive airway in often uncooperative, nonfasted, unstable, and/or critically ill patients. Choosing the appropriate premedication, induction drug, and paralytic will maximize the success of tracheal intubation and minimize complications.

Etomidate evokes synaptic vesicle exocytosis without increasing miniature endplate potentials frequency at the mice neuromuscular junction

Etomidate is an intravenous anesthetic used during anesthesia induction. This agent induces spontaneous movements, especially myoclonus after its administration suggesting a putative primary effect at the central nervous system or the periphery. Therefore, the aim of this study was to investigate the presynaptic and postsynaptic effects of etomidate at the mouse neuromuscular junction (NMJ). Diaphragm nerve muscle preparations were isolated and stained with the styryl dye FM1-43, a fluorescent tool that tracks synaptic vesicles exo-endocytosis that are key steps for neurotransmission. We observed that etomidate induced synaptic vesicle exocytosis in a dose-dependent fashion, an effect that was independent of voltage-gated Na(+) channels. By contrast, etomidate-evoked exocytosis was dependent on extracellular Ca(2+) because its effect was abolished in Ca(2+)-free medium and also inhibited by omega-Agatoxin IVA (30 and 200nM) suggesting the participation of P/Q-subtype Ca(2+) channels. Interestingly, even though etomidate induced synaptic vesicle exocytosis, we did not observe any significant difference in the frequency and amplitude of miniature end-plate potentials (MEPPs) in the presence of the anesthetic. We therefore investigated whether etomidate could act on nicotinic acetylcholine receptors labeled with α-bungarotoxin-Alexa 594 and we observed less fluorescence in preparations exposed to the anesthetic. In conclusion, our results suggest that etomidate exerts a presynaptic effect at the NMJ inducing synaptic vesicle exocytosis, likely through the activation of P-subtype voltage gated Ca(2+) channels without interfering with MEPPs frequency. The present data contribute to a better understanding about the effect of etomidate at the neuromuscular synapse and may help to explain some clinical effects of this agent.

[Peripartum cardiomyopathy: interdisciplinary challenge]

Peripartum cardiomyopathy (PPCM) is a rare type of heart failure which presents towards the end of pregnancy or in the first 5 months after delivery. Depending on the geographical location the incidence is reported in the literature as 1:300 up to 1:15,000. There are a number of known risk factors, such as multiparity and age of the mother over 30 years. The symptoms of PPCM correspond to those of idiopathic cardiomyopathy. The diagnosis is mainly carried out using echocardiography which shows a clear reduction of systolic left ventricular function. The therapeutic approach is the same as for idiopathic cardiomyopathy and in this context it is absolutely necessary to show caution concerning the state of pregnancy and the resulting contraindications for therapeutic drugs. The prognosis is dependent on recovery from the heart failure during the first 6 months postpartum. The lethality of the disease is high and is given in the literature as up to 28 %. Because of its complexity PPCM is an interdisciplinary challenge. In the peripartum phase a close cooperation between the disciplines of cardiology, cardiac surgery, neonatology, obstetrics and anesthesiology is indispensable. For anesthesiology the most important aspects are the mostly advanced unstable hemodynamic condition of the mother and the planning and implementation of the perioperative management. This article presents the case of a patient in advanced pregnancy with signs of acute severe heart failure and a suspected diagnosis of PPCM. The patient presented as an emergency case and delivery of the child was carried out using peridural anesthesia with a stand-by life support machine.

Propofol administration to the fetal-maternal unit reduces cardiac injury in late-preterm lambs subjected to severe prenatal asphyxia and cardiac arrest

BACKGROUND

Cardiac dysfunction is reported to occur after severe perinatal asphyxia. We hypothesized that anesthesia of the mother with propofol during emergency cesarean section (c-section) would result in less cardiac injury (troponin T) in preterm fetuses exposed to global severe asphyxia in utero than anesthesia with isoflurane. We tested whether propofol decreases the activity of proapoptotic caspase-3 by activating the antiapoptotic AKT kinase family and the signal transducer and activator of transcription-3 (STAT-3).

METHODS

Pregnant ewes were randomized to receive either propofol or isoflurane anesthesia. A total of 44 late-preterm lambs were subjected to in utero umbilical cord occlusion (UCO), resulting in asphyxia and cardiac arrest, or sham treatment. After emergency c-section, each fetus was resuscitated, mechanically ventilated, and supported under anesthesia for 8 h using the same anesthetic as the one received by its mother.

RESULTS

At 8 h after UCO, the fetuses whose mothers had received propofol anesthesia had lower plasma troponin T levels, and showed a trend toward a higher median left ventricular ejection fraction (LVEF) of 84% as compared with 74% for those whose mothers had received isoflurane. Postasphyxia activation of caspase-3 was lower in association with propofol anesthesia than with isoflurane. Postasphyxia levels of STAT-3 and the AKT kinase family rose 655% and 500%, respectively with the use of propofol anesthesia for the mother.

CONCLUSION

The use of propofol for maternal anesthesia results in less cardiac injury in late-preterm lambs subjected to asphyxia than the use of isoflurane anesthesia. The underlying mechanism may be activation of the antiapoptotic STAT-3 and AKT pathways.