|
|
||||||||
Ann Thorac Surg 2005;80:1946-1947
© 2005 The Society of Thoracic Surgeons
a Department of Cardiothoracic Surgery, Sydney Children's Hospital, Sydney, New South Wales, Australia
b Department of Clinical Perfusion, Prince of Wales Hospital, Sydney, New South Wales, Australia
c Department of Cardiothoracic Surgery, Prince of Wales Hospital, Sydney, New South Wales, Australia
Accepted for publication May 4, 2004.
* Address correspondence to Dr Grant, Department of Cardiothoracic Surgery, Prince of Wales Hospital, Barker St, Randwick 2031, Sydney, Australia (Email: grantpe{at}sesahs.nsw.gov.au).
| Abstract |
|---|
|
|
|---|
| Introduction |
|---|
|
|
|---|
This system was designed to deliver blood cardioplegia either diluted or at the patient's hematocrit. Temperature control can be suited to cold, tepid, or warm cardioplegia delivery. Furthermore, it also allows addition of different substrates at known concentration, dispensing with the purchase of expensive brand cardioplegia solutions and extra devices.
| Technique |
|---|
|
|
|---|
|
The 1-liter Plasma-lyte solution plastic bag is used as the cardioplegia reservoir. The total prime volume of the cardioplegia circuit is 300 mL, allocated as 200 mL in the bag and 100 mL in the tubing. The excess 700 mL of solution is directed to the oxygenator, constituting the prime.
Once cardiopulmonary bypass (CPB) is stabilized and the patient's temperature is 28°C, blood is derived from the arterial (aortic) line by removing clamp B and applying clamp A (see Fig 1). When the volume in the cardioplegia reservoir reaches 900 mL, clamp B is reapplied to isolate the cardioplegia from the main circuit. Substrates are added through the pressure port three-way tap, and the final cardioplegia solution is circulated to the desired temperature. Delivery is achieved by applying clamps B and C, and releasing clamp A (Fig 1).
For a typical cardioplegia induction at our institution, we use the set described as above and a total volume of 900 mL at 10°C. The substrates used are potassium chloride (KCl) and sodium bicarbonate (Na HCO3). We add 20 mmol KCl to the cardioplegia blood; thus, its final concentration will be around 23 mEq/L. We also add 10 mmol Na HCO3 to keep pH around 7.45. For warm induction, cardioplegia is heated to 36°C, and the substrates are the same as for cold induction.
Repeated doses are administered at 15- to 20-minute intervals, with 500 mL of pure pump blood at 10°C. If there is mechanical or electrical activity, 5 mmol KCl is added to the cardioplegia blood. Immediately before aortic unclamping, a last dose of warm (36°C) cardioplegia ("warm shot") is administered (5 mmol KCl is added to 1 L blood).
Cardioplegia delivery is based mainly on pressure: flow is adjusted to keep the cardioplegia line pressure of 150 mm Hg, which corresponds to approximately 80 mm Hg in the aortic root.
For myocardial revascularization, we normally do the distal anastomoses first and the proximals with a side clamp. We use the Multiple Delivery Cardioplegia Set (Medtronic, Minneapolis, MN), which allows for vein grafts to be perfused either with cardioplegia (as soon as the distal anastomose is performed), or warm blood (when the aortic clamp is released). When retrograde cardioplegia is applied, the pressure is measured directly from the cannula, and kept between 30 mm Hg and 40 mm Hg, so that flow varies accordingly.
The system configuration for pediatric cases is the same, but it differs in size: the tubing is 3/16 inches thick with a prime volume of 100 mL; the cardioplegia reservoir is a 500-mL Plasma-lyte solution plastic bag; and there is a one-way valve at the end of the cardioplegia line (just before connection to the cardioplegia cannula) to avoid air entering the system. The KCl concentration is the same as for adults. The cardioplegia doses for children less than 30 kg are 20 mL/kg and 10 mL/kg for induction and repeated doses, respectively.
| Comment |
|---|
|
|
|---|
From January 1996 to December 2003, 5,828 adults with median age of 67.75 years (range, 18 to 92) were operated on with the use of cardiopulmonary bypass (coronary artery disease or valve disease, or both, comprising 5,479 cases [94.1%], and others, 349 [5.9%]). Reoperations accounted for 9.1% (521) of the procedures. Overall mortality was 2.26% and the use of intraoperative and postoperative intraaortic balloon counterpulsation for low-output syndrome was 1.3%. Median cross-clamp and CPB times were 52 and 87 minutes, respectively. Seventy-six percent of the hearts resumed spontaneous sinus rhythm after aortic cross-clamp removal.
This cardioplegia circuit proved to be reliable, with good and reproducible results. It is quite simple to handle: it needs only one roller set from the main pump and two tubing clamps to operate. This system also suits any perfusion technique and surgical preference: the way of delivery can be antegrade or retrograde, including perfusion of vein grafts and coronary ostia; temperature is easily set to warm, cold, or tepid. It allows continuous or intermittent delivery with controlled perfusion pressure. The cardioplegia hematocrit can be high (patient's hematocrit) or low (diluted). In relation to cardioplegia additives, we solely use potassium chloride and sodium bicarbonate, but it is possible to add any other substrate such as magnesium sulfate, glutamate, aspartate, citrate, Tham, and so forth, with known concentrations.
Regarding expenses, this system costs only 25% of other brand cardioplegia systems in our market (Au$ 50, against Au$ 200 for the most expensive; cardioplegia solution and additives not included). Total savings per year are significant, even in a moderately busy unit. If commercially available cardioplegia solutions or special perfusion pumps and their maintenance were to be included, the difference in cost would be even greater.
In conclusion, this system to deliver blood cardioplegia is suitable for any clinical myocardial protection strategy. Moreover, it is cost effective, simple, and has proved to be reliable for more than 25 years.
| Acknowledgments |
|---|
|
|
|---|
| References |
|---|
|
|
|---|
This article has been cited by other articles:
![]() |
V. A. Ferraris, J. R. Brown, G. J. Despotis, J. W. Hammon, T. B. Reece, S. P. Saha, H. K. Song, E. R. Clough, L. J. Shore-Lesserson, L. T. Goodnough, et al. 2011 Update to The Society of Thoracic Surgeons and the Society of Cardiovascular Anesthesiologists Blood Conservation Clinical Practice Guidelines Ann. Thorac. Surg., March 1, 2011; 91(3): 944 - 982. [Abstract] [Full Text] [PDF] |
||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| ANN THORAC SURG | ASIAN CARDIOVASC THORAC ANN | EUR J CARDIOTHORAC SURG |
| J THORAC CARDIOVASC SURG | ICVTS | ALL CTSNet JOURNALS |