Cardiac Anaesthesia

Argon: The Future Organ Protectant? Suresh G Nair Annals of Cardiac Anaesthesia 2019 22(2):111-112

Propofol for sedation for direct current cardioversion Bruna Galvão de Wafae, Rose Mary Ferreira da Silva, Henrique Horta Veloso Annals of Cardiac Anaesthesia 2019 22(2):113-121 Direct current cardioversion is a low-risk and standard procedure to restore normal sinus rhythm in patients with tachyarrhythmias. It requires sedation to facilitate the procedure, as it is painful and distressful. The preferred anesthetic drug must be short acting, producing conscious sedation, to enable rapid recovery after the procedure. In this sense, this narrative review focuses on the critical analysis of recent randomized studies and presents about the safety and effectiveness of propofol, comparing it with other established sedatives, mainly etomidate and midazolam. The research was performed on MEDLINE database with Propofol and Cardioversion keywords. In most cases, propofol comes to be the best option, with a quick recovery time and low rates of side effects. Different studies have demonstrated no inferiority when comparing to other drugs and, when these adverse events happened, they were easily and quickly handled. Exceptions in this scenario are those patients, particularly the elderly, with baseline important structural heart disease, in which etomidate with fentanyl has been pointed to lead to better hemodynamic stability.

A complete review of preclinical and clinical uses of the noble gas argon: Evidence of safety and protection Francesca Nespoli, Simone Redaelli, Laura Ruggeri, Francesca Fumagalli, Davide Olivari, Giuseppe Ristagno Annals of Cardiac Anaesthesia 2019 22(2):122-135 The noble gas argon (Ar) is a “biologically” active element and has been extensively studied preclinically for its organ protection properties. This work reviews all preclinical studies employing Ar and describes the clinical uses reported in literature, analyzing 55 pertinent articles found by means of a search on PubMed and Embase. Ventilation with Ar has been tested in different models of acute disease at concentrations ranging from 20% to 80% and for durations between a few minutes up to days. Overall, lesser cell death, smaller infarct size, and better functional recovery after ischemia have been repeatedly observed. Modulation of the molecular pathways involved in cell survival, with resulting anti-apoptotic and pro-survival effects, appeared as the determinant mechanism by which Ar fulfills its protective role. These beneficial effects have been reported regardless of onset and duration of Ar exposure, especially after cardiac arrest. In addition, ventilation with Ar was safe both in animals and humans. Thus, preclinical and clinical data support future clinical studies on the role of inhalatory Ar as an organ protector.

Terlipressin versus norepinephrine to prevent milrinone-induced systemic vascular hypotension in cardiac surgery patient with pulmonary hypertension Mai Mohsen Abdelazziz, Hadil Magdi Abdelhamid Annals of Cardiac Anaesthesia 2019 22(2):136-142 Introduction: Milrinone at inotropic doses requires the addition of a vasoconstrictive drug. We hypothesized that terlipressin use could selectively recover the systemic vascular hypotension induced by milrinone without increasing the pulmonary vascular resistance (PVR) and mean pulmonary artery pressure (MPAP) as norepinephrine in cardiac surgery patients. Patients and Methods: Patients with pulmonary hypertension were enrolled in this study. At the start of rewarming a milrinone 25 μg/kg bolus over 10 min followed by infusion at the rate of 0.25 μg/kg/min. Just after the loading dose of milrinone, the patients were randomized to receive norepinephrine infusion at a dose of 0.1 μg/kg/min (norepinephrine group) or terlipressin infusion at a dose of 2 μg/kg/h (terlipressin group). Heart rate, mean arterial blood pressure (MAP), central venous pressure, MPAP, systemic vascular resistance (SVR), PVR, cardiac output were measured after induction of anesthesia, after loading dose of milrinone, during skin closure, and in the intensive care unit till 24 h. Results: Milrinone decreased MAP (from 79.56 ± 4.5 to 55.21 ± 2.1 and from 78.46 ± 3.3 to 54.11 ± 1.1) and decreased the MPAP (from 59.5 ± 3.5 to 25.4 ± 2.6 and from 61.3 ± 5.2 to 25.1 ± 2.3) in both groups. After norepinephrine, there was an increase in the MAP which is comparable to terlipressin group (P > 0.05). Terlipressin group shows a significant lower MPAP than norepinephrine group (24.5 ± 1.4 at skin closure vs. 43.3 ± 2.1, than 20.3 ± 2.1 at 24 h vs. 39.8 ± 3.8 postoperatively). There is a comparable increase in the SVR in both group, PVR showed a significant increase in the norepinephrine group compared to the terlipressin group (240.5 ± 23 vs. 140.6 ± 13 at skin closure than 190.3 ± 32 vs. 120.3 ± 10 at 24 h postoperatively). Conclusion: The use of terlipressin after milrinone will reverse systemic hypotension with lesser effect on the pulmonary artery pressure.

Comparison of full outline of unresponsiveness score and Glasgow Coma Scale in Medical Intensive Care Unit Jamileh Ramazani, Mohammad Hosseini Annals of Cardiac Anaesthesia 2019 22(2):143-148 Context: The Glasgow Coma Scale (GCS) is the most commonly used scale, and Full Outline of Unresponsiveness (FOUR) score is new validated coma scale as an alternative to GCS in the evaluation of the level of consciousness. Aim: The aim of the current study was to evaluate FOUR score and GCS ability in predicting the outcomes (Survivors, nonsurvivors) in Medical Intensive Care Unit (MICU). Setting and Design: This was an observational and prospective study of 300 consecutive patients admitted to the MICU during a 14 months' period. Materials and Methods: FOUR score, GCS score, and demographic characteristics of all patients were recorded in the first admission 24 h. Statistical Analysis Used: A receiver operator characteristic (ROC) curve, Hosmer–Lemeshow test, and Logistic regression were used in the statistical analysis (95% confidence interval). Results: Data analysis showed a significant statistical difference in FOUR score and GCS score between survivors and nonsurvivors (P < 0.0001, P < 0.0001; respectively). The discrimination power was good for both FOUR score and GCS (area under ROC curve: 87.3% (standard error [SE]: 2.1%), 82.6% [SE: 2.3%]; respectively). The acceptable calibration was seen just for FOUR score (χ2 = 8.059, P = 0.428). Conclusions: Both FOUR score and GCS are valuable scales for predicting outcomes in patients are admitted to the MICU; however, the FOUR score showed better discrimination and calibration than GCS, so it is superior to GCS in predicting outcomes in this patients population.

In search of a better measuring scale of consciousness Jayantee Kalita, Usha K Misra Annals of Cardiac Anaesthesia 2019 22(2):149-150

The effect of perioperative magnesium sulfate on blood sugar in patients with diabetes mellitus undergoing cardiac surgery: A double-blinded randomized study Rabie Soliman, Hussein Nofal Annals of Cardiac Anaesthesia 2019 22(2):151-157 Objective: The aim of the present study was to evaluate the perioperative effect of magnesium infusion on blood sugar level in patients with diabetes mellitus undergoing cardiac surgery. Design: This was a double-blind randomized study. Setting: The study was conducted at cardiac center. Patients: The study included 122 adult patients. Intervention: Group M – The patients received a continuous infusion of magnesium sulfate (without a loading dose) at 15 mg/kg/h. The infusion rate was started 20 min before induction maintained during surgery and the first postoperative 24 h. The medication was prepared by adding 5 g magnesium sulfate in 50 ml syringe. Group C – The patients received equal amount of normal saline. Measurements: The monitors included heart rate, mean arterial blood pressure, central venous pressure, urine output, blood levels of magnesium, sugar, and potassium. Results: The blood sugar level and the required insulin significantly decreased with Group M than Group C (P < 0.05). There were minimal changes in the potassium level in Group M, but potassium decreased in patients of Group C (P < 0.05). The amount of urine output was too much higher in Group M than Group C (P < 0.05). The pharmacological and mechanical support significantly decreased with Group M than Group C (P < 0.05). The hospital and Intensive Care Unit length of stay significantly decreased with Group M than Group C (P < 0.05). Conclusion: The magnesium sulfate produced a better-controlled effect on the blood sugar level. It decreased the requirement of insulin infusion and minimized the changes in the blood level of potassium.

The effect of cerebral oximeter use on the shunt placement concerning carotid endarterectomy surgery Dilek Ceyhan, Cengiz Ovali Annals of Cardiac Anaesthesia 2019 22(2):158-161 Background: During carotid arterial endarterectomy (CAE) surgery, an intraluminal shunt is used to prevent hypoperfusion, which can be caused by a cross-clamping cerebral ischemia. However, routine shunt use is not recommended. Various cerebral monitoring techniques are used to determine the need for shunt placement. In this study, retrospective analysis of data on the efficacy of cerebral oximetry in the decision of shunt use during elective CAE surveys was planned. Materials and Methods: We collected data on 68 patients operated under general anesthesia between December 2016 and December 2017. Patients were evaluated for near infrared spectrometry (NIRS) and stump pressure values and whether shunt was placed or not. Results: Eight (11.7%) patients were shunting. NIRS value after cross-clamping was lower in patients with shunt. Stump pressure values were below 40 mmHg. Conclusions: Cerebral monitoring in elective CAE operations has great importance in determining the necessity of using intraluminal shunt to reduce the complications that may occur.

Hyperkalemia in ambulant postcardiac surgery patients during combined therapy with angiotensin-converting enzyme inhibitor, spironolactone, and diet rich in potassium: A report of two cases and review of literature Aanchal Dixit, Gauranga Majumdar, Prabhat Tewari Annals of Cardiac Anaesthesia 2019 22(2):162-168 Introduction: Potassium is the most abundant cation in intracellular compartment. A deficiency or excess of its serum concentration can be deleterious to the one suffering from a cardiac ailment. Post cardiac surgery patients are often on multiple drugs like angiotensin receptor blockers (ARBs), angiotensin converting enzyme inhibitors (ACEI), diuretics including potassium sparing diuretics which are known to predispose for hyperkalemia. We report two postoperative cases who developed life threatening hyperkalemia despite normal renal function due to a combination of factors like treatment with ACEI, potassium sparing diuretics, high dietary intake of potassium and we also discuss renal handling of potassium in this review of literature. Methodology: We present a case series of two cases of cardiac surgery, who presented in the emergency department with hyperkalemia, managed conservatively and detailed history revealed that patient were also on very high nutritional potassium. Result: Both the patients responded to conservative management and there was no recurrence of such episodes once the dose of diuretics was adjusted and diet modification advised. Conclusion: In India, many patients are from a low socioeconomic background and often resort to cheap and filling food items like bananas. This dietary factor should be kept in mind while prescribing patients with these medications and adequate counseling regarding diet should be done.

Perioperative anesthesia management for pulmonary endarterectomy: Adopting an established European Protocol for the Asian Population Yufan Chen, Zihui Tan, Shitalkumar S Shah, Kenny W T Loh Annals of Cardiac Anaesthesia 2019 22(2):169-176 Background: Anesthesia for pulmonary endarterectomy (PEA) has always been one of the challenges of anesthesia. As one of the leading cardiothoracic institutions in Southeast Asia, our hospital has vast interest in this subject. A local multidisciplinary team was deployed to an expert center in the United Kingdom (UK), and the experience was then integrated to the care of our patients. We present a case series of ten patients undergoing anesthesia for PEA, a first for our institution, and discuss techniques as well as potential complications. Methods: Patients with chronic thromboembolic pulmonary hypertension were reviewed by a multidisciplinary team, and those who were suitable for surgical intervention subsequently underwent PEA. A total of ten patients were identified and operated on. The perioperative management and conduction of anesthesia for all patients followed a protocol adapted from the expert center in the UK, with revisions to cater to our Asian population. Results: In the ten patients operated on, eight of them were successfully extubated on the first postoperative day. Apart from one incident of prolonged ventilator usage due to reperfusion lung injury and pneumonia, there were no major respiratory or hemodynamic complications. Certainly, six of the ten patients developed subdural hemorrhage after the commencement of enoxaparin, although none of them sustained any permanent neurological deficits. Conclusion: We have demonstrated that with careful planning and a well-outlined protocol, anesthesia for PEA in an Asian population can be achieved with favorable outcomes. Further fine-tuning of the protocol is still required based on local expertise.