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A Simple Heat Exchanger for Cooling Irrigating Solutions During Transurethral Prostatectomy
THE JouRNAL OF UROLOGY
Vol. 87, No. 2 February 1962 Copyright © 1962 by The Williams & Wilkins Co. Printed in U.S.A.
A SIMPLE HEAT EXCHANGER FOR COOLI~G IRRIGATING SOLUTIONS DURING TRANSURETHRAL PROSTATECTOMY B. LYMAN STEWART
Regional hypothermia for transurethral prostatectomy was first reported by Landes and co-workers. 1 They demonstrated a decrease in blood loss during transurethral surgery, when a refrigerated irrigating solution was used. This modality has not been widely used, nor has its value been proven. Cockett and co-workers 2 found no appreciable difference in the blood loss during transurethral surgery with or without a refrigerated irrigating medium I have tried using ice packs around the water supply. This is cumbersome and doesn't provide a uniformly cooled irrigating medium, nor is the medium as cold as it should be. In spite of these disadvantages, the use of a refrigerated irrigating solution did seem to curtail the blood loss and improve visability during the procedure. It was then decided to further explore the seeming benefits from refrigerated irrigating solution. Dr. Robert Anderson of Los Angeles has designed and built one of the best heat exchangers now available for general hypothermia. Through his generosity and assistance we decided to try his apparatus in transurethral prostatectomy. The results were gratifying. \Ve were able to maintain a constant inflow temperature at from 4° to S°C and usually around 7°C. When it was learned that the heat exchanger would function as desired, Dr. Anderson suggested the use of a smaller, cheaper, and less elaborate heat exchanger. He designed and hand built the apparatus to be described. The total cost of this first unit including the pump, hose, and cooling can was only $235. The simplified heat exchanger consists of 1.5 feet of copper tubing sealed in a n1etal case. The latter is 6 inches high and the same in diameter. There are two garden hose connections on the exchanger. To each one of these is attached a 6 foot length of plastic garden hose. These Accepted for publication June 30, 1961. 1 Landes, R. R., Leonard, K., Ranson, C. T. and Davila, J.: Localized hypothermia for transurethral prostatic resection. J. Urol., 82: 245, 1954. 2 Cockett, A. T. K., Schnitz, J. and Frank, D.: Use of refrigerated solutions during transurethral surgery. J. Urol., 85: 632, 1961. 178
hoses carry the cooling water to and from the exchanger. There are two smaller connections which are the intake and output for the rubber plastic tubing transporting the irrigating medium. The heat exchanger is easily disconnected from the tubing and hoses. It can then be sterilized by autoclaving with no dismantling of its own parts. Figure 1 shows the heat exchanger. The remainder of the equipment consists of a small electric, waterproof sump pump and screen, and a 10 gallon galvanized can. Figure 2 illustrates the entire apparatus ready for use.
Fw. 1. Heat exchanger with hoses and tubing attached.
The sump pump is placed in the bottom of the 10 gallon can. Water is added until the pump is completely covered by 2 to 3 inches of water. Coarsely chopped ice and some salt are then added until the can is full. After the pump is turned on, only a few minutes are required for the exchanger to become operational. \Vhen the irrigating medium flows at 400 to 500 cc per minute, the temperature of the irrigating medium entering the bladder is 4 ° to S°C. If the rate of flow is below 275 cc per minute, the temperature of the inflow is 2° to 4 °C. The latter rate of flow is too slow for rapid work and good visibility when larger arteries are encountered. We have used refrigerated irrigating media in 150 consecutive prostatectomies. We have had thermocouples in the rectum at the prostatic level and high in the rectum. Using the heat exchanger the rectal temperature at the prostatic
SIMPLE HEAT EXCHANGER
Frc. 2. Complete assembly shows galvanized can, sump pump, hoses, heat excha,nger and water supply.
level has been from 82F to 87F. High in the rectum the temperature has neYer been under 94F and is usually 97F. \Ye have had no extraYasations to check on the rapid drop in rectal temperature that should accompany this complication. Apparently we have not had enough absorption of irrigating medium from the operative area to cause any sharp or alarming drop in general body temperature. I believe that the latter drop might be beneficial if bleeding were scyere There should be no dangrr from grneralized hypothermia unless the) body ternperature stayed below 84F. I don't believe that would be possible during this type of surgery. No primary hemorrhage of any magnitude occurred in any of these 150 patients. Xo trans-
ftrnions were given during or immediately after oprration. There were two hemorrhages. One occurred on the fourth and the other on the tenth postoperative day, both in tlw sarne patient. This was the only one of the 150 who was given a transfusion and that wa,~ the postoperative hemorrhage 10 after tlH-: first operation. vVe intend to make exact measurements of the blood loss during smgery. At wt: can state that the blood loss seems much the visibility during the surgery is better u,nd the amount of irrigating medium used has been less. The larger arteries don't spurt as nor does the generalized oozing seem to be as promi" neut. IYlrnn sorbital is used there may be mon:
180
B. LYMAN STEWART
fogging when the solution is around 4°C. If a face mask is worn, the eye piece may easily become fogged when the room temperature and the humidity are high. I use distilled water unless venous sinuses are opened. ·when this occurs, sorbital is added. If too many large venous sinuses are opened, it is best that the completion of the operation be postponed to another day. The patient may not like this, but he will be alive. We have used refrigerated medium in 3 cases of bladder tumors. It seems as if the tumors are
more easily cut. This may be a result of a firming of the fronds from the cold. Further experience will clarify this. SUMMARY
A description of construction and use of a simple heat exchanger for use in transurethral prostatectomy have been present. Comments on the experience in 150 consecutive cases of transurethral prostatectomy have been presented. 1893 Wilshire Blvd., Los Angeles 57, Cal.
If you plan to attend the ANNUAL MEETING of the AMERICAN UROLOGICAL ASSOCIATION, INC. in Philadelphia (May 14-17, 1962), please preregister early. Pre-Registration forms will be found in the advertising section, p. 4, in the front part of this journal. Merely pull out the Pre-Registration form, fill it in, and mail it.
Vol. 87, No. 2 February 1962 Copyright © 1962 by The Williams & Wilkins Co. Printed in U.S.A.
A SIMPLE HEAT EXCHANGER FOR COOLI~G IRRIGATING SOLUTIONS DURING TRANSURETHRAL PROSTATECTOMY B. LYMAN STEWART
Regional hypothermia for transurethral prostatectomy was first reported by Landes and co-workers. 1 They demonstrated a decrease in blood loss during transurethral surgery, when a refrigerated irrigating solution was used. This modality has not been widely used, nor has its value been proven. Cockett and co-workers 2 found no appreciable difference in the blood loss during transurethral surgery with or without a refrigerated irrigating medium I have tried using ice packs around the water supply. This is cumbersome and doesn't provide a uniformly cooled irrigating medium, nor is the medium as cold as it should be. In spite of these disadvantages, the use of a refrigerated irrigating solution did seem to curtail the blood loss and improve visability during the procedure. It was then decided to further explore the seeming benefits from refrigerated irrigating solution. Dr. Robert Anderson of Los Angeles has designed and built one of the best heat exchangers now available for general hypothermia. Through his generosity and assistance we decided to try his apparatus in transurethral prostatectomy. The results were gratifying. \Ve were able to maintain a constant inflow temperature at from 4° to S°C and usually around 7°C. When it was learned that the heat exchanger would function as desired, Dr. Anderson suggested the use of a smaller, cheaper, and less elaborate heat exchanger. He designed and hand built the apparatus to be described. The total cost of this first unit including the pump, hose, and cooling can was only $235. The simplified heat exchanger consists of 1.5 feet of copper tubing sealed in a n1etal case. The latter is 6 inches high and the same in diameter. There are two garden hose connections on the exchanger. To each one of these is attached a 6 foot length of plastic garden hose. These Accepted for publication June 30, 1961. 1 Landes, R. R., Leonard, K., Ranson, C. T. and Davila, J.: Localized hypothermia for transurethral prostatic resection. J. Urol., 82: 245, 1954. 2 Cockett, A. T. K., Schnitz, J. and Frank, D.: Use of refrigerated solutions during transurethral surgery. J. Urol., 85: 632, 1961. 178
hoses carry the cooling water to and from the exchanger. There are two smaller connections which are the intake and output for the rubber plastic tubing transporting the irrigating medium. The heat exchanger is easily disconnected from the tubing and hoses. It can then be sterilized by autoclaving with no dismantling of its own parts. Figure 1 shows the heat exchanger. The remainder of the equipment consists of a small electric, waterproof sump pump and screen, and a 10 gallon galvanized can. Figure 2 illustrates the entire apparatus ready for use.
Fw. 1. Heat exchanger with hoses and tubing attached.
The sump pump is placed in the bottom of the 10 gallon can. Water is added until the pump is completely covered by 2 to 3 inches of water. Coarsely chopped ice and some salt are then added until the can is full. After the pump is turned on, only a few minutes are required for the exchanger to become operational. \Vhen the irrigating medium flows at 400 to 500 cc per minute, the temperature of the irrigating medium entering the bladder is 4 ° to S°C. If the rate of flow is below 275 cc per minute, the temperature of the inflow is 2° to 4 °C. The latter rate of flow is too slow for rapid work and good visibility when larger arteries are encountered. We have used refrigerated irrigating media in 150 consecutive prostatectomies. We have had thermocouples in the rectum at the prostatic level and high in the rectum. Using the heat exchanger the rectal temperature at the prostatic
SIMPLE HEAT EXCHANGER
Frc. 2. Complete assembly shows galvanized can, sump pump, hoses, heat excha,nger and water supply.
level has been from 82F to 87F. High in the rectum the temperature has neYer been under 94F and is usually 97F. \Ye have had no extraYasations to check on the rapid drop in rectal temperature that should accompany this complication. Apparently we have not had enough absorption of irrigating medium from the operative area to cause any sharp or alarming drop in general body temperature. I believe that the latter drop might be beneficial if bleeding were scyere There should be no dangrr from grneralized hypothermia unless the) body ternperature stayed below 84F. I don't believe that would be possible during this type of surgery. No primary hemorrhage of any magnitude occurred in any of these 150 patients. Xo trans-
ftrnions were given during or immediately after oprration. There were two hemorrhages. One occurred on the fourth and the other on the tenth postoperative day, both in tlw sarne patient. This was the only one of the 150 who was given a transfusion and that wa,~ the postoperative hemorrhage 10 after tlH-: first operation. vVe intend to make exact measurements of the blood loss during smgery. At wt: can state that the blood loss seems much the visibility during the surgery is better u,nd the amount of irrigating medium used has been less. The larger arteries don't spurt as nor does the generalized oozing seem to be as promi" neut. IYlrnn sorbital is used there may be mon:
180
B. LYMAN STEWART
fogging when the solution is around 4°C. If a face mask is worn, the eye piece may easily become fogged when the room temperature and the humidity are high. I use distilled water unless venous sinuses are opened. ·when this occurs, sorbital is added. If too many large venous sinuses are opened, it is best that the completion of the operation be postponed to another day. The patient may not like this, but he will be alive. We have used refrigerated medium in 3 cases of bladder tumors. It seems as if the tumors are
more easily cut. This may be a result of a firming of the fronds from the cold. Further experience will clarify this. SUMMARY
A description of construction and use of a simple heat exchanger for use in transurethral prostatectomy have been present. Comments on the experience in 150 consecutive cases of transurethral prostatectomy have been presented. 1893 Wilshire Blvd., Los Angeles 57, Cal.
If you plan to attend the ANNUAL MEETING of the AMERICAN UROLOGICAL ASSOCIATION, INC. in Philadelphia (May 14-17, 1962), please preregister early. Pre-Registration forms will be found in the advertising section, p. 4, in the front part of this journal. Merely pull out the Pre-Registration form, fill it in, and mail it.