Comments on dynamic cardiomyoplasty

LETTERS

254

TO THE

FDI I OR

ventilated with an Fr@ close to 0.21. clearly too low to achieve adcquatc oxypznation. A <,ttustrophe was prevcntcd I*‘$ clamping the air supply lint and setting the blender to deliver 100’5 oxygen. The alarm stopped when the ‘iir supply overpressurization was reduced by the clamp. In order to prevent this kind of potential catastrophe. we make the following suggcstronx: For ancsthcsioloEists: 1. The anesthesia machine in the heart room should be equipped with wall supply prcssurc gauges for air and oxygen: 2. As part of the machine checkout, if the air and oxygen wall supply gauges arc not equal ai approximately SO psi, aIc11 the perfusionist; 3. During a critical incident when hypoxic blood is being delivered to the patient. the anesthesiologist should check the ait and oxygen wall supply pressures and report his/her findings to the perfusionists; For Pcrfusionists: I. As part of setting up for bypass. connect alternatively and singly the air and oxygen supply lines to the blender in order to demonstrate that the alarm reed is functioning; 2. Have air and oxygen supplied to the bypass machine in such a way that either can be immediately disconnected. Quick disconnects should be placed between the blender and the wall supply of air and oxygen; 3. Each heart-lung machine should have back-up tanks for air and oxygen (which can even he the backup E cylinders on the anesthesia machine) fitted to regulators set to output pressures at 50 psi; For cquipmcnt manufacturers: 1. Provide air and oxygen supply pressure gauges to the blender; 2. Modify the current alarm module so that vented gas does not go to the oxygenator; 3. Develop a system similar to the “fail-safe” system on anesthesia machines so if there is an imbalance of supply gas pressure, only the Row of oxygen is permitted and the flow of air through the blender is discontinued.

.lunathan V. Roth, MD Duvid W. Fried, MS, Ed, C’CP Albert Einstein Medical Center Philadelphia, PA REFERENCES

I. Modulus

II Anesthesia Machine: Preoperative Checklists, Operation and Maintenance Manuals. Ohmeda. Madison, WI 2. Operator Manual: North American Drager, Telford, PA 3. Sechrist Air Oxygen Mixer Operational Instructions. Sechrist Industries. Inc, Anaheim, CA.

Comments

on Dynamic

4. Rubsamen DS: Continuous blood gas monitoring during cardiopulmonary bypass-How soon will it be the standard of care’? J Cardiothorac Anesth 4: l-4, IYYO

Cardiomyoplasty

To the Editor I was interested to read the case conference in the August 1992 issue of thcJoumcl/. In our center, we have performed four dynamic cardiomyoplasty operations in the past one and a half years and were the first center to do so in India. Our results have been very encouraging. I would like to make the following comments regarding the case presented. 1. Prehydration with 500 mL of Ringer’s lactate without a PCWP monitor. especially in a patient with a left ventricular ejection fraction of 8% to lo%, may be a hazardous procedure. 2. One-lung anesthesia with an endobronchial double-lumen tube is likely to add to the danger of the anesthetic in these critically ill patients: why not use a single-lumen tube (as we have done in our cases)? The two runs of unsustained VT and multiple PVCs observed when the left lung was collapsed and the latissimus dorsi muscle was fed into the left chest after the resection of the rib could have been due to hypoxemia due to one-lung anesthesia (no SaO? and SVO Z values mentioned at this point of time). It may also be more difficult to control “bucking” when the relaxant’s effects are reversed (to test the threshold of the cardiomyostimulator) with a double-lumen endotracheal tube than with a single-lumen tube. 3. The need to reverse the patient during testing the threshold of the cardiomyostimulator may be avoided by the use of short-acting muscle relaxants, namely vecuronium or atracurium, especially as infusions, and by the use of a peripheral nerve stimulator to assess the degree of recovery of the neuromuscular junction at the time of testing. Dr K. Murulidhar Department of Anaesthesiology B.M. Birla Heart Research Centrc Calcutta. India

LETTERS TO THE EDITOR

255

REFERENCE 1. Robinson

RJS, Truong

DT, Odim J, et al: Case conference:

A 62-year-old

man is scheduled

for a new cardiac surgical procedure:

Dynamic cardiomyoplasty. J Cardiothorac Vast Anesth 6:476-487,1992

Atrio-Ventricular

Groove

Rupture Diagnosed by Perioperative Echocardiography

Transesophageal

To the Editor: In response to and in support of the article by Lingreen et al,’ we report a case of A-V groove rupture that was primarily diagnosed with TEE and confirmed after pericardiectomy. A 70-year-old white female patient was admitted with myocardial ischemia complicated by acute pulmonary edema. Cardiac catheterization showed 100% occlusion of the right coronary artery (RCA) and 75% stenosis of the left circumflex artery (LCX). Due to the rapid deterioration of her condition, an emergency PTCA of the LCX was attempted. The vessel restenosed after initial dilatation. A repeat attempt resulted in dissection of the vessel. The patient developed severe chest pain and was stabilized with an intra-aortic balloon pump (IABP) in addition to nitroglycerin. The patient was brought to the operating room for emergency CABG. After establishing appropriate general anesthesia, the TEE probe was introduced. The transgastric view revealed concentric hypertrophy and global hypokinesis of the left ventricle with a 35% to 40% ejection fraction. Pulling the probe back by 4 cm showed an aneurysm of the posterior wall of the left ventricle measuring 3 cm in width (Fig 1). Because the patient had undergone angioplasty with resultant dissection of the LCX artery, we suspected a rupture of the A-V groove and pseudoaneurysm formation. Our surgical colleague was able to confirm these findings after sternotomy and pericardiectomy. It was decided to bypass the LCX vessel and by very gentle cardiac manipulation to prevent rupture of the pseudoaneurysm and a potentially fatal outcome. Postbypass TEE still showed the pseudoaneurysm. The patient was weaned off bypass with inotropic support and the IABP. The postoperative course remained guarded for several weeks with eventual recovery. Although our patient had a known acute dissection of the LCX, there was no evidence of the potentially fatal complication of A-V groove rupture either from the cardiac catheterization or the relatively stable clinical state. The aneurysm’s free rupture into the pericardium was prevented by fibrinous adhesions resulting from the previous myocardial infarctions. A primary surgical repair was not attempted because of limited success of such a procedure. However, great care was exercised during surgical dissection and manipulation of the heart to prevent further disruption and a possible fatality.

University

Jawad U. Hasnain, MD Robert J. N. Watson, MB Mary LaFreniere, CCVT Department of Anesthesiology of Maryland School of Medicine Baltimore, MD

REFERENCE 1. Lingreen R, Eaton M, Lappas DG, Barzilai B: Diagnosis by transesophageal after mitral valve replacement. J Cardiothor Vast Anesth 5:61-62, 1991

echocardiography

of atrioventricular

groove dissection