|Year : 2008 | Volume
| Issue : 1 | Page : 77
Lumbar Discectomy of a Patient of Mitral Stenosis with Chronic Atrial Fibrillation Under Epidural Anaesthesia
Vinaya R Kulkarni1, Maya A Jamkar2, Anil Dhole1, Sandeep Junghare3
1 Lecturer, Department of Anaesthesiology, B.J.Medical College,Pune,Maharashtra, India
2 Associate Professor, Department of Anaesthesiology, B.J.Medical College,Pune,Maharashtra, India
3 Chief Resident, Department of Anaesthesiology, B.J.Medical College,Pune,Maharashtra., India
|Date of Acceptance||18-Dec-2007|
|Date of Web Publication||19-Mar-2010|
Vinaya R Kulkarni
Flat A- 202, Nakshtra Apartment,Erandavane, Pune, 411004
Source of Support: None, Conflict of Interest: None
A 60-year-old female patient posted for discectomy of lumbar region L 3 -L 4 was accidently diagnosed to have chronic atrial fibrillation of rheumatic aetiology.This is a case report of this patient of critical mitral stenosis with mild mitral regurgitation with chronic atrial fibrillation managed successfully under lower thoracic epidural anaesthesia,in prone position without any complication.
Keywords: Discectomy, Prone position
|How to cite this article:|
Kulkarni VR, Jamkar MA, Dhole A, Junghare S. Lumbar Discectomy of a Patient of Mitral Stenosis with Chronic Atrial Fibrillation Under Epidural Anaesthesia. Indian J Anaesth 2008;52:77
|How to cite this URL:|
Kulkarni VR, Jamkar MA, Dhole A, Junghare S. Lumbar Discectomy of a Patient of Mitral Stenosis with Chronic Atrial Fibrillation Under Epidural Anaesthesia. Indian J Anaesth [serial online] 2008 [cited 2020 Jan 18];52:77. Available from: http://www.ijaweb.org/text.asp?2008/52/1/77/60602
| Introduction|| |
Mitral stenosis(MS) is almost always rheumatic in origin. Pure MS occurs in 25% of patients who develop long term rheumatic sequelae.  The remaining patients have either combined lesions in one valve or combined valvular disease. Infrequent causes include congenital defects seen in infancy and childhood,malignant carcinoid,rheumatic arthritis and prolapse of left atrial myxomas into the mitral valve opening.  MS exhibits a 2:1 female preponderance.  Prevalence is 0.4% and it increases with age. 
Atrial fibrillation is a known complication of mitral valve disease. Non cardiac surgery of patients with valvular heart lesions especially mitral stenosis carries many risks for anaesthesia.There is no universal recommended ideal anaesthesia technique for such patients.The decision has to be individualized as per the patient's general and cardiac condition and the type of non cardiac surgery.
| Case report|| |
A 60-year-old lady weighting 50kg with chief complaints of tingling and numbness of both lower limbs since three months and difficulty while walking came to orthopaedic OPD for treatment. She was diagnosed to have prolapsed interverteral disc L 3 -L 4 for which she was posted for discectomy and referred for pre anaesthetic evaluation. There was no history of any surgery or any other major illness in the past.
On examination, her general condition was normal except irregularity of pulse rate was noticed. There was mid-diastolic murmur in cardiovascular system.
Her haemogram, urine examination, bleeding and clotting time were normal. Blood sugar was 102 mg.dL-1, blood urea was 40 mg.dL -1 , and serum electrolytes Na+/K+ were 132/4.2 mEq.L -1 . Her ECG showed irregularly irregular rhythm with absent P waves. X ray chest showed moderate cardiomegaly. She was advised 2D echo which showed critical mitral stenosis (MS) with valve area of 1 cm 2 with mild mitral regurgitation (MR). There were no clots in left atrium. Ejection fraction was 50%. Physician diagnosed her to have critical MS and MR with chronic atrial fibrillation (AF) and advised to start digoxin and anticoagulation therapy postoperatively.
| Anaesthetic management|| |
The urgency and the need of the surgery and role of conservative management was discussed with orthopaedic surgeons considering various risk factors for anaesthesia. Surgeons denied role of conservative management and went ahead with definitive surgery and insisted on regional anaesthesia. Merits and demerits of general anaesthesia were compared against regional anaesthesia. Though general anaesthesia would have been a better choice for this patient, it was decided to perform this surgery under epidural anaesthesia as patient was clinically asymptomatic. This was a unanimous decision by surgeons and anaesthesiologists. We are practicing epidural anaesthesia for almost all patients posted for discectomies of ASA I & II in our institute.
She was advised infective endocarditis prophylaxis and anxiolytic oral diazepam 10 mg a night prior to surgery. 500 ml of whole blood was kept ready. On the day of surgery, her pulse rate was 80/min, irregularly irregular, BP- 110/80 mm Hg and irregularly irregular rhythm of atrial fibrillation on ECG, there were no crepts or rhonchi. High risk consent in view of cardiac pathology was taken. Cardiac drugs were kept ready and her urinary bladder was catheterised. Her preoperative urine output was 200 ml. Intravenous access was taken with 18 G intracath. CVP line was put through internal jugular vein. CVP was 8 cm of water. Ranitidine 1mg.kg -1 and ondansetron 0.1 mg.kg -1 were given intravenously. She was preloaded with 500 ml of Ringer lactate. ECG monitor and pulse oximeter were attached and defibrillator was kept ready.
Epidural catheter,numbered 16, was put at T11 - T12 space with all aseptic precautions. Test dose of 2% lidocaine with adrenaline was given. Later a total dose of 8 ml lidocaine without adrenaline was required for adequate action. The catheter was fixed.
She was given prone position with due precautions. Oxygen was given by ventimask. Her vital parameters, ECG and oxygen saturation were monitored throughout the procedure. The patient was given 1000ml of crystalloids intraoperatively in the form of Ringer's lactate and 0.9% dextrose normal saline. The surgery was uneventful and over within 45 minutes. There was approximately 30 ml of blood loss. The urine output of the patient was 25 ml at the end of the surgery. Her postoperative period was uneventful. The postoperative analgesia was provided with 0.125% bupivacaine through the epidural catheter which was removed 24 hours later.
| Discussion|| |
Modern lumbar spinal surgery ranges from disc excision through tiny incisions to extensive instrumentation.  The anaesthetic techniques must be adapted to the particular type of surgery. These cases traditionally have been performed with general anaesthesia. Spinal or epidural anaesthesia is more commonly preferred for simple disc excision.  Lumbar spinal fusion can be performed with low thoracic epidural anaesthesia.  The virtues of epidural anaesthesia are less bleeding and improved postoperative epidural analgesia.  Safe application of regional anaesthesia requires care, skill and discretion by both surgeon and anaesthesiologist. 
General anaesthesia is often preferred over central neuraxial blockade for anaesthetic management of patients with mitral stenosis. General anaesthesia is preferred because of greater patient acceptance and ability to perform operations of long duration in the prone position with a secured airway.  This choice is made often because peripheral sympathetic nervous system blockade produced by regional anaesthesia can lead to undesirable decrease in systemic vascular resistance. Indeed, when regional anaesthesia is selected, epidural is often recommended due to gradual onset of peripheral sympathetic nervous system blockade. 
Regional anaesthesia decreases blood loss and improves operating conditions by decreasing peripheral venous pressure which reduces venous blood loss in the operative field. Awake patient can self position to avoid nerve injury to brachial plexus and pressure necrosis to face which may occur in the malpositioned patient under general anaesthesia. Less bleeding would facilitate dissection and removal of disc in less time as less time is needed to achieve haemostasis. Pulmonary complications are more common with general anaesthesia.
Hypotension in spine surgery is related to the position rather than to anaesthetic technique.  The outcome of discectomy and laminectomy patients under spinal and general anaesthesia has been compared. 
Our patient had critical MS with trivial MR. Although the interval between rheumatic fever and development of MS is at least 2 years, patients are usually asymptomatic for 2 decades and symptoms generally develop in the 3 rd and 4 th decades of life. In this case, this patient was totally asymptomatic for 6 decades and diagnosed only when she was posted for discectomy. There was no history of decompensation during deliveries. She had two children with history of full term normal vaginal deliveries.
This patient also had chronic atrial fibrillation. Perioperative treatment goals of AF are restoration and maintenance of sinus rhythm, control of ventricular rate and prevention of thromboembolic complications. , Immediate synchronized electrical cardioversion is required when AF is associated with rapid ventricular rate, haemodynamic compromise, worsening of left ventricular function or evidence of myocardial ischaemia. Digoxin has a limited role in intraoperative setting because of its slow onset of action.
Amiodarone is studied extensively and is found effective for perioperative management of these cases. , Amiodarone is referred by American Heart Association's Guidelines 2002 as the drug of choice for pharmacologic conversion of AF  . Amiodarone and defibrillator were kept ready for this case but fortunately not required as there was no further rhythm disturbances observed intraoperatively.
The patient was not receiving any anticoagulant preoperatively which eased our choice of regional anaesthesia. Though there are studies , in literature where spinal and epidural anaesthesia was successfully used in patients receiving anticoagulants.
In this patient, it was chronic AF and patient was clinically asymptomatic. The surgeon and his team were very fast and insisted for regional anaesthesia for better field and as it was a single disc. Hence, keeping in mind the precautions and risks involved under regional anaesthesia and problems of prone position, we still decided to give epidural anaesthesia for this case.
Continuous monitoring of intra-arterial blood pressure and arterial filling pressures is useful when a major surgery is planned in patients of cardiac diseases who are symptomatic at rest. 
However, as this was a single discectomy without any major fluid shifts, hence we used noninvasive blood pressure monitoring. Intraoperative fluid management must be carefully titrated as these patients are susceptible to volume overload and to the development of pulmonary oedema. We used CVP line and gave titrated fluids initially before prone position was given. Pulmonary artery catheter (PAC) would have been ideal in such cases as it was an afterthought for us. But this procedure is not without risks, there can be precipitation of arrhythmias.  Our patient did not have any documented left ventricular dysfunction and due to the presence of MS and mild MR, the wedge pressure would not reliably reflect end diastolic pressure.  We did not think that cardiac output or CVP measurements would have altered our management as it was a short duration surgery. Hence we suggest that use of PAC in cases of valvular heart diseases should be assessed on a case to case basis and to be used if it can provide reliable information by Helder et al in his study where he used combined spinal epidural anaesthesia for labour and unexpected caesarian section in a patient with mitral and aortic stenosis and insufficiency. 
There are case reports where epidural anaesthesia was used in patients with aortic stenosis. ,, These case reports boosted our decision to use epidural anaesthesia in this case.
Prone position for spine surgeries poses many problems for anaesthesiologists. Hypotension, chest compression, pressure necrosis are some of the important complications of prone position.  The risk increases in patients with valvular heart diseases.  But precautions if taken like adequate leg stockings and prior preloading can avoid the known complications of prone position which we followed in this case and managed without any complication. Another important complication is venous air embolism which is rare. ,
In conclusion, a patient of rheumatic mitral stenosis with chronic atrial fibrillation poses many risks for anaesthesiologist. Spine surgery of such patients in prone position increases the risk even more. This case, however, was managed successfully under epidural anaesthesia without any complications, with proper perioperative precautions. As it was a short duration surgery, hence it offered advantage for our management. We suggest that the alternative of epidural anaesthesia for such patients may be helpful only for short duration surgeries without major fluid shifts.
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