Anesthetic Management of a Patient with Dilated Cardiomyopathy and End-stage Renal Disease for Emergency Strangulated Hernia Repair Surgery.

Dilated cardiomyopathy (DCMP) is a myocardial disease associated with dilatation of one or both the ventricles, impaired myocardial contractility, decreased cardiac output, and increased ventricular filling pressures. Patients with end-stage renal disease are dependent on renal replacement therapy to survive and often manifest with a variety of pathological organ dysfunction. We present a case of DCMP and chronic kidney disease posted for emergency reduction of strangulated umbilical hernia under general plus epidural anesthesia.

INTRODUCTION

Dilated cardiomyopathy (DCMP) is a myocardial disease associated with dilatation of one or both the ventricles, impaired myocardial contractility, decreased cardiac output, and increased ventricular filling pressures.[1] It is the most common type of nonischemic cardiomyopathy, the prevalence being 920/100,000.[2] It is defined by the presence of (a) fractional myocardial shortening <25% and/or left ventricular ejection fraction (LVEF) <45%; and (b) left ventricle end diastolic diameter >117% excluding any known cause of myocardial disease.[3] Chronic renal failure and end-stage renal disease (ESRD) are characterized by a progressive decrease in glomerular filtration rate below 20 ml/min and 10 ml/min of normal function, respectively. Patients with ESRD are dependent on renal replacement therapy to survive and often manifest with a variety of pathological organ dysfunction.[4]

We present a case of DCMP and chronic kidney disease posted for emergency reduction of strangulated umbilical hernia under general plus epidural anesthesia.

CASE REPORT

A 26-year-old female patient weighing 35 kg, presented with strangulated umbilical hernia. Her previous medical records revealed she was a known case of DCMP and chronic kidney disease since 2 years. She was presently on treatment with tablet digoxin 0.25 mg, tablet furosemide 40 mg, and tablet carvedilol 12.5 mg once a day. She gave a history of repeated hospital admissions in the past 2 years with features suggestive of congestive heart failure (CHF) and was on regular twice weekly maintenance hemodialysis, last being 2 days before the surgery.

On preanesthetic evaluation, her heart rate was 96 beats/min, regular; blood pressure was 106/72 mmHg; respiratory rate was 16 breaths/min. On auscultation grade, three ejection systolic murmurs were audible. There were no rhonchi or crepitations. Air entry was equal bilaterally. There was no hepatomegaly, ascitis, or pedal edema. The skin overlying the hernia appeared necrosed.

The preoperative 12 lead electrocardiogram (ECG) revealed normal sinus rhythm. Echocardiography demonstrated global hypokinesia, poor systolic function with LVEF of 28%, all 4 chambers dilated, severe mitral regurgitation, tricuspid regurgitation, pulmonary regurgitation, and moderate pulmonary artery hypertension. Chest radiograph revealed cardiomegaly with normal lung fields. Her investigations showed Hb 7.9 g/dl, total leukocyte count TLC 12.9 × 1000/μl, platelet count 219 × 1000/mm3, urea 28.9 mg/dl, creatinine 3.6 mg/dl, sodium 138 mEq/L, potassium 4.5 mEq/L, international normalized ratio of 1.05.

A high-risk written and informed consent was obtained in view of cardiac and renal disease. After shifting to the operating room, an 18-gauge intravenous (IV) cannula was secured. Under strict aseptic precautions, an 18-gauge epidural catheter was inserted into the epidural space at T10-11 interspace using loss of resistance to air technique. A 22-gauge right radial arterial cannula was secured since the left hand had an arteriovenous fistula. Under local anesthesia, a 7 Fr, 15 cm triple lumen central venous catheter was inserted into a right internal jugular vein under ultrasound guidance for intensive hemodynamic monitoring.

The following parameters were monitored: Two lead ECG (II and V5), invasive blood pressure, central venous pressure (CVP), oxygen saturation by pulse oximetry, end-tidal carbon dioxide, body temperature, and urine output. FloTrac® continuous cardiac monitoring was done to monitor cardiac output, cardiac index and stroke volume variability (SVV).

Anesthesia was induced with injection etomidate 0.2 mg/kg, injection fentany l 3 μg/kg. Injection cisatracurium 0.15 mg/kg IV was given to facilitate intubation with size 7.0 mm endotracheal tube. Anesthesia was maintained with 50% air in oxygen, desflurane 4%–6%, and intermittent boluses of 1 mg cisatracurium. An epidural infusion of 0.05% ropivacaine with 2 μg/ml fentanyl was started at 5 ml/h. The CVP was maintained between 8 and 10 cmH2O, cardiac output of 6.8 L/min, cardiac index of 5.5 L/min/m2, and systemic vascular resistance (SVR) of 835 dyne/s/cm5. Arterial blood gas revealed a pH of 7.381, pO2193 mmHg, pCO232.1 mmHg, base excess - 5.8 mmol/L, HCO3− 18.6 mmol/L.

We started injection noradrenaline infusion at 0.08 μg/kg/min and injection dobutamine infusion at 5 μg/kg/min which were tapered slowly towards the end of surgery. Surgeons found only ascitic fluid as the sac contents which was then aspirated. There was no bowel or omentum. The neck of the hernia was found to be very narrow, and defect was closed without a mesh. The procedure lasted for 90 min. Blood loss was about 100 ml. Intraoperatively, a total of 400 ml of normal saline was given. Paracetamol 500 mg IV was given as a means to achieve multimodal analgesia. At the end of surgery, after the return of respiratory efforts, the residual neuromuscular blockade was reversed with injection glycopyrrolate 0.01 mg/kg and injection neostigmine 0.05 mg/kg and extubated. The patient had stable hemodynamics throughout the procedure [Figure 1]. The patient was shifted to surgical recovery room, and all the intraoperative monitoring was continued postoperatively. A continuous epidural infusion of 0.05% ropivacaine with 1 μg/ml fentanyl was continued postoperatively.

Figure 1

Graph of hemodynamic parameters

All her preoperative medications were continued as per the recommended scheduled dosing and timing. The patient was shifted from the recovery room after 4 h. She underwent dialysis on the postoperative day 1 and was then discharged on postoperative day 4.

DISCUSSION

Anesthetic management of a patient with DCMP can be challenging as these patients possess a minimal cardiac reserve resulting in high incidence of morbidity and mortality. DCMP is characterized by the left ventricular or biventricular dilatation and impaired ventricular contractility, which carries a high risk of progressive congestive cardiac failure.[2]

The goals of anesthetic management include avoidance of drug-induced myocardial depression, maintenance of normovolemia, and prevention of increased ventricular afterload. Anesthetic management needs to be customized in patients with ejection fraction <45%. Agents that cause minimal myocardial depression such as etomidate, narcotics, and ketamine are preferable.[56]

Epidural analgesia is advantageous owing to the fact that it decreases the afterload and limits the stress response to surgery. Fluid management is also critical as overloading such a patient may precipitate a CHF.

Keeping in mind the above goals, the anesthetic modality of general plus epidural anesthesia was planned. The induction was performed with etomidate to minimize the hemodynamic changes during induction. The stress response to laryngoscopy and intubation was blunted using injection xylocard 1 mg/kg, 90 s before laryngoscopy. Cisatracurium was used as muscle relaxant in view of the high creatinine. It also has higher cardiovascular stability and is devoid of tachycardia due to histamine release that is seen with atracurium which was undesirable for our patient.[7]

A vasopressor to offset the vasodilating effect of the anesthetic is a rational approach. This was achieved in our case using injection noradrenaline infusion. The cardiac output was maintained using injection dobutamine infusion. As fluid management remained critical, the replacement was done based on SVV as observed in FloTrac® sensor system. FloTrac® sensor system is based on the principle that pulse pressure is proportional to stroke volume (SV) and inversely proportional to aortic compliance. It analyzes arterial pulse wave morphology without the need for external calibration.

It requires only a radial arterial catheter without the need of a central or peripheral venous access.[89] It offers information on SV, SVV, and SVR.

We may thus conclude by saying that safe management of a case of DCMP and ESRD calls for a thorough understanding of pathophysiology to maintain adequate cardiac output strictly guided fluid replacement to avoid hypovolemia or overload and meticulous intra- and post-operative pain management.

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Conflicts of interest

There are no conflicts of interest.