Case Reports

Anesthetic management of a patient with dilated cardiomyopathy and low ejection fraction

Pravin Ubale, MD*, Ashish Mali, MD**, Pinakin Gujjar, MD***

*Associate Professor; **Assistant Professor; ***Professor & Head

Dept. Of Anaesthesiology, TNMC & BYL Nair Hospital, Mumbai.

Correspondence: Dr. Pravin Ubale, Anand Bhavan , B–16, TNMC & BYL Nair Hospital., Mumbai Central, Mumbai (India); Tel: 9322211472; E-mail: drpravinubale@gmail.com

ABSTRACT

We report a case of 54 year male, a case of dilated cardiomyopathy with low ejection fraction who underwent Functional Endoscopic Sinus Surgery (FESS) under general anesthesia. Anesthetic management of such patients is always requires the highest level of expertise as they are usually complicated by progressive congestive cardiac failure (CHF). The uneventful course of the anesthesia in the presented case was related to the thorough systemic evaluation and careful anesthetic strategy.

Key words: Dilated cardiomyopathy; Anesthesia, General; Operative Time

Citation:Ubale P, Mali A, Gujjar P. Anesthetic management of a patient with dilated cardiomyopathy and low ejection fraction. Anaesth Pain & Intensive Care 2014;18(4):446-48

INTRODUCTION

Dilated cardiomyopathy (DCM) is one of the group of diseases that affects primarily the myocardium. In DCM a portion of the myocardium is dilated often without any obvious cause. Left or right ventricular systolic pump function of the heart is impaired leading to progressive cardiac enlargement and hypertrophy, a process called remodeling. DCM is the most common form of non-ischemic cardiomyopathy. The incidence of DCM is reported to be 5 to 8 cases per 100,000 population per year.1 It occurs more frequently in men than women, and is most common between 20 and 60 yrs of age. Anesthetic management of patients with cardiomyopathy with reduced systolic function is challenging and may be associated with high mortality.2 Maintaining cardiovascular stability with optimal hemodynamic parameters during the anesthetic management of patient with DCM can be extremely challenging. We report successful management of a patient with DCM with low ejection fraction (EF) who underwent Functional Endoscopic Sinus Surgery (FESS) under general anesthesia.

CASE REPORT

A 54 year male patient was referred to our institute for FESS due to frontal mucocele. He was a diagnosed case of DCM and hypertension. He had a history of dyspnea (NYHA functional class II), but no history of nocturnal dyspnea, orthopnea and palpitations. On physical examination there were no signs of congestive cardiac failure e.g. raised JVP, ankle edema or hepatomegaly. His heart rate was 76/min and blood pressure was 130/86 mmHg. On auscultation no signs of rhonchi or crepitations were present. His recent 2-D Echo showed DCM, depressed LV systolic function (EF 20%), Mild MR, Mild AR, Mild PH, and PASP by TR jet 35 mmHg. X-ray chest showed cardiomegaly. There was sinus rhythm on ECG. His hemoglobin was 12 gm/dl and all biochemical parameters were within normal limits. He was on treatment, tab amlodipine 5 mg BID, Tab furosemide 40 mg OD, tab atorvastatin 20 mg OD. Cardiologist consultation was requested for patient’s management, who advised to continue the above mentioned drugs. Patient and his relatives were explained about anesthetic risk and a high risk consent was obtained.

General anesthesia was planned for removal of frontal mucocele by endoscopic approach. All emergency drugs and defibrillation were kept ready. Standard monitors (ECG, NIBP and SpO2) were attached. With all aseptic precaution arterial line and triple lumen internal jugular venous catheterization was achieved under local anesthesia. Patient was premedicated with inj. glycopyrrolate 0.2 mg, inj. midazolam 1 mg, inj. fentanly 100 µg and inj. hydrocortisone 100 mg. For gastric acid prophylaxis inj. ondensetron 8 mg and inj. ranitidine 50 mg given prior to induction. Anesthesia was induced with double diluted inj. thiopentone sodium 250 mg slowly given till loss of eye reflex and vecuronium bromide 8 mg was given after mask ventilation was confirmed. Patient’s trachea was intubated with 8.5 mm ID cuffed endotracheal tube. Throat pack was inserted. Patient was maintained with sevoflurane in O2/N2O and intermittent dose of vecuronium bromide. Intraoperatively SpO2 was maintained between 98 to 99%, HR 70 to 80 beats/min, systolic BP was maintained between 110-130 mmHg, and diastolic BP was maintained between 70-80 mmHg with continuous use of invasive monitoring. Central venous pressure was kept at 8-10 cmH2O. Blood loss was minimal and patient received one litre of crystalloids over a period of 2 hrs with urine output of 200 ml. Patient remained hemodynamically stable throughout the procedure. Throat pack was removed and adequate suctioning was done at the end of surgery. Neuromuscular blockage was reversed with inj. glycopyrrolate 0.4 mg and inj. neostigmine 2.5 mg and patient was extubated and shifted to intensive care unit for postoperative monitoring. After observing 24 hrs in the intensive care unit, patient was shifted to ward.

DISCUSSION

Dilated cardiomyopathy is a primary myocardial disease of varied causes. It is characterized by left ventricular or biventricular dilatation and impaired ventricular contractility.3 Several types of treatment modalities for dilated cardiomyopathy are available to improve systolic function. Patients should initially be managed medically. Biventricular pacing, cardioplasty or cardiac transplant may also be required to improve cardiac function.4 Arrhythmias are managed with amiodarone and/or an automatic implantable cardioverter defibrillator (ICD). Medical management to improve systolic function includes administration of diuretics, beta-blockers, angiotensin converting enzyme (ACE) inhibitors.

Anesthetic management of patients with severe cardiomyopathies is associated with high morbidity and mortality, so requires proper planning, preparation and meticulous monitoring. The goals for anesthetic management consist of 1) avoidance of drug induced myocardial depression, 2) maintenance of normovolemia, and 3) prevention of increased ventricular afterload. Patients of DCM may deteriorate from induction of anesthesia till extubation and also in the postoperative period, so early recognition and immediate intervention of hemodynamic instability with appropriate vasoactive or inotropic medications is required to prevent catastrophic events. Life threatening ventricular arrhythmias may also occurs during the intraoperative period, so all emergency drugs such as lignocaine and amiodarone should be ready in the operating room.

As patients are on diuretics from preoperative period, they tends to be dehydrated, a further cause for hypotension during the perioperative period. However this dehydration is generally beneficial for these patients as it improves limited cardiac function. Preloading may not be possible in these patients as it may lead to CCF. So fluid management is an important task in these patients. In our patient fluid therapy was guided by monitoring blood pressure, CVP and urine output. Arrhythmias may also occur due to diuretics when potassium or magnesium levels are decreased. So one must have a close watch on electrolyte imbalance for correction as early as possible.5

Most of the anesthetic drugs tend to depress myocardium, slow the heart rate and dilate the blood vessels. Therefore, selection of drugs that have minimal myocardial depressant effect is very essential in these patients. Induction agents like propofol and thiopentone sodium have depressant effect on heart. Etomidate is the ideal induction agent in these patients. As Etomidate was not available in our institute, we use thiopentone sodium as induction agent.

The predictors of poor prognosis in our patient were, depressed LV systolic function (EF 20%), mild MR, mild AR, and mild PH. Also patient was a known case of hypertension. For these reasons, condition was explained to the patient as well as relatives and high risk consent was obtained. Patient’s hemodynamic status was carefully observed and fluid management was guided by CVP. We monitored this patient in the intensive care unit, because, the postoperative management also requires intensive monitoring, similar to the intraoperative period until the patient is stabilized.

In conclusion careful and intense hemodynamic monitoring and slow and judicious titration of anesthetic drugs and fluids is important in patient of DCM with low ejection fraction.

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