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Colorimetric estimation of blood loss during surgery of burns
t3riti~h .7ournal qf Pl~*stic Nttrgery ( i 97~), 25, 13°- 134
COLORIMETRIC E S T I M A T I O N OF B L O O D LOSS D U R I N G S U R G E R Y OF B U R N S
By D. MAHLER,1 M.D. and RUSSELLM. DAVIES, F.F.A.R.C.S. Rayne Fellow in Burns, Mclndoe Memorial Research Unit, Queen Victoria Hospital, East Grinstead, and Senior Consultant Anaesthetist, Queen Victoria Hospital, East Grinstead THERE is a trend today towards earlier excision of burned tissues in an attempt to avoid the onset of severe infections (Sachs and Watson, 1969 ; MacMillan, 197o). One of the problems associated with early excision is massive blood loss, which, unless rapidly and accurately replaced, prejudices the survival of a seriously ill patient. The earliest reference to the measurement of blood loss during operation, which we found, was the paper of Gatch and Little (I924} which described their acid-haematin technique (see below). Since then more and more attention has been paid to the fact that the operative blood loss is often several times greater than the surgeon's estimate (Blain, I929 ; Coller and Maddock, I932 ). Furthermore, no correlation exists between blood loss and changes in haematocrit, haemoglobin and plasma-protein concentrations (Wangensteen, 1942; Crook et al., 1946). It also became apparent that replacement of the blood loss during surgical operations is an essential part of the operation and blood loss requiring transfusion should be anticipated before the body's ability to compensate fails and hypotension develops (Baronofsky et al., 1946 ; Hercus et al., I96I ). The most commonly used methods of determining operative blood loss are gravimetric and volumetric, i.e. the weighing of all swabs and pads before and after use and recording the weight difference and measuring blood aspirated from the operative field. Inaccuracies are due mainly to measuring tissues or fluids other than blood. (Baronofsky et al., 1946 ; Stanton et al., 1949 ; Muir and Grummit, 1954 ; Hercus et al., 1961 ; Jackson, 1962 ; Thornton et al., 1963 ; McIvor, 1967). The circulating blood volume may be calculated by means of dyes or radioactive tracers. The readings cannot be repeated at frequent intervals, however, and the method is only useful for a single reading at a selected time (Thornton et al., 1963 ; Conizaro et al., 1964 ; Mclvor, 1967). The colorimetric method which we have used was first described by Gatch and Little (1924) and was based on the comparison of a standard solution with a solution of acid-haematin made by washing blood-soaked material. It was modified in 1949 by Stanton et al., using a spectrophotometer for greater accuracy and subsequently evolved into a technique based on the haemolysis and dilution of blood in tap water in a simple domestic washing machine (Alsop et al., 1963 ; Rustad, 1963 ; Bond, 1969). The blood loss can be calculated from a series of graphs previously prepared from known dilutions of blood or instruments such as the photoelectric cell of Evans Electroselenium (Roe et al., 1962) and the Perometer (Rustad, 1962) to give direct readings. Other variations of the colorimetric method are the Cyan-Haemoglobin system (Bond, 1969) or direct colorimetric determination of haemoglobin (Perkins and Miller, 1969). 1 D r Mahler, M . D . is seconded f r o m the D e p a r t m e n t of Plastic Surgery, Rarnbam G o v e r n m e n t Hospital, Haifa, Israel. 13 °
COLORIMETRIC ESTIMATION OF BLOOD LOSS DURING SURGERY OF BURNS I3I PRESENT TECHNIQUE The method is based on measuring the haemoglobin lost by the Perometer blood oss monitor 1 which provides a direct reading. During desloughing operations there
-
i
FIG. x. The Perometer, blood loss monitor.
f is unavoidably necrotic debris mixed with the b}6od and separation is essential tor accurate results. After preliminary work with " h o m e - m a d e " equipment a copper filter was fitted to the recirculating line of the Pero~r~eter. This proved wholly effective providing that it was cleaned after each use. x Perometer, A.B. Lars Ljungberg, Sweden.
I32
BRITISH JOURNAL OF PLASTIC SURGERY
The Perometer (Fig. I) consists of a washing machine, into which 4 ° litres of water are introduced together with Perosol, a haemolysing agent. All swabs, pads and linen soaked with blood and any aspirated fluids are collected in the tank (Fig. 2) where
FIG. 2. T h e washing machine section of the Perometer.
:4 FIG. 3.
T h e monitoring unit of the Perometer. T h e button (lower right) is for setting the patient's pre-operative haemoglobin value.
the blood is washed out and haemolysed to oxyhaemoglobin. The solution is circulated continuously from the washing machine via the copper filter through a measuring cell of a photometer, which registers the solution's haemoglobin content. This measuring cell is set at the patient's pre-operative haemoglobin value (Fig. 3), enabling
COLORIMETRIC ESTIMATION OF BLOOD LOSS DURING SURGERY OF BURNS *33 the photometer to register directly the quantities of blood lost by the patient. The photometer responds only to light of the wavelength produced by oxyhaemoglobin and is therefore not affected by the presence of other liquids, dyes or soluble elements. Two scales are available : a low range, which reads 5-600 ml. and a high range which reads up to 5 litres of blood loss. The accuracy measured against known amounts of blood was + ~ - 2 per cent (Toldy and Scott, I969).
RESULTS The technique has been used during 3 i surgical procedures in 18 patients, whose burns varied from 8 to 7° per cent of body surface, mostly full thickness. The age range was from 3 years to 65 years and the range of pre-operative haemoglobin levels was 9"3 g. per cent to I4.6 g. per cent. Surgical intervention consisted of the excision of burned areas and the taking of autografts. The first procedure was carried out from the 5th to 25th day post-burn. Further similar procedures were undertaken as necessary. In our experience the Perometer gives accurate, immediate and continuous monitoring of the blood loss during operation and the speed of intravenous transfusion may, therefore, be continuously regulated. It requires no special skill. It does not need repeated blood sampling or intravenous injections, important points in patients whose veins are at a premium. Potential criticism of the Perometer technique (Bond, I969), i.e. errors of inadequate mixing, incomplete haemolysis, dead spaces in the washing machine or inaccuracy in measurement of water, were found to be minimal as repeated checks with known aliquots of blood of known haemoglobin values showed accuracy up to + 2 per cent. Errors due to the physiological response of the patient during surgery appear to have been overcome by limiting the period of surgery to a maximum of I hour. The main source of error remains the accuracy of the pre-operative haemoglobin measurement which should be made within 24 hours of surgery. Members of the operating team were asked to make subjective estimations of the visible and probable (e.g. from donor sites) blood loss. These varied from over-estimation of 25 per cent to under-estimation up to 75 per cent. The degree of inaccuracy decreased with practice, but clinical estimation of blood loss remained unreliable. The accuracy of the technique imparts confidence in deciding not only whether to transfuse but also how much and at what rate. The aim was to restore the patient's haemoglobin to a minimum of I I g. per cent. I f the level was below this pre-operatively, the deficit was calculated from the estimated blood volume and added to the measured operative blood loss. It is probably also wise to allow for post-operative bleeding from the raw surfaces particularly donor sites. In a few cases this was measured by lysing the dressings on the Ioth day and losses of I5o-25o ml., according to the size of the donor site, were recorded. SUMMARY The Perometer when fitted with a suitable filter is the most satisfactory method available for measuring blood loss during surgery on burned patients. The authors wish to express their thanks to Dr V. Whitmarsh for his work on the preliminary home-made machine; to Mr Hackett for his continuing interest, particularly in his work in determining blood losses into the donor site dressings; to all our surgical colleagues and nursing staff in the Mclndoe Burns Centre; and to Mr P. Broadbery, Chief Medical Photographer at this hospital
134
BRITISH JOURNAL OF PLASTIC SURGERY REFERENCES ALsoI,, W., EMERY, J. L. and ZACIIARY, R. B. (1963). Measurement of blood loss during operation. British Medical Journal, I, 125. BARONOVSKY, I. D., TRELOAr~, A. E. and WANC;ENSXEEN, O. H. (1946). Blood loss in operations : a statistical comparison of losses as determined by the gravimetric and colorimetric methods. Surgery, 20, 761-769. BLAIN, A. (1929). Impressions resulting from 3,ooo transfusions of unmodified blood. Annals of Surgery, 89, 917-922. BOND, A. G. (1969). Determination of operative blood loss. Anaesthesia, 24, 219-229. CANIZARO, P. C., SAWYER, R. B. and SwrrZER, W. E. (I964). Blood loss during excision of third-degree burns. Archives of Surgery, 88, 8o0-802. CULLER, F. A. and MADOOCK, W. G. (1932). Dehydration, attendant on surgical operations. Journal of the American Medical Association, 99, 875-88o. CROOK, C. E., IoB, V. and CULLER, F. A. (1946). Correction of blood loss during surgical operations. Surgery, Gynecology and Obstetrics, 82, 417-422. GATCH, W. D. and LITTLE, W. D. (1924). Amount of blood loss during some of the more common operations. Journal of the American Medical Association, 83, lO75-1o76. HERCUS, V. M., REEVE, T. S., TRACY, G. D. and RUNDLE, F. F. (1961). Blood loss during surgery. British Medical Journal, 2, 1467-1469 . JACKSON, D. (I962). Extensive primary excision and grafting of deep burns, in " Research in Burns ", p. 327 . Philadelphia : F. A. Davies Company. McIvoR, J. (1967). A method of assessing operative and post-operative blood loss. British Journal of Oral Surgery, 5, I-IO. MACMILLAN, B . G . ( I 9 7 0 ). Indications for early excision. Surgical Clinics of North America, 5 ° , 1337-1345. MUIR, I. F. K. and GRUMMIT, M. (1957)- Early excigion of burns with particular reference to blood replacement. " Transactions of the First Congress of the International Society of Plastic Surgery," p. 98, Williams & Wilkins Company. PERKINS, J. B. and MILLER, H. C. (I969). Blood loss during transurethral prostatectomy. Journal of Urology, IOX, 93-97. ROE, C. F., GARDINER, A. J. S. and DUDLEY, H. A. F. (I962). A simple instrument for rapid, continuous determination of operative blood loss. Lancet, I, 672-673. RUSTAD, H. (I963). Measurement of operative blood loss. Acta Chirurgica Seandinavica, 125, 14-18. SACHS, A. and WATSON, J. (I969). Four years' experience at a specialised Burn Centre. Lancet, I, 718-72I. STANTON, J. R., LYON, R. P., FREIS, E. D. and SMIXHWlCK, R. H. (1949). Blood and " available fluid " (thiocyanate) volume studies in surgical patients ; Part I I - - o p e r a tire and post-operative blood loss with particular emphasis upon uncompensated red cell loss. Surgery, Gynecology and Obstetrics, 89, I 8 I - i 9 O. THORNTON, J. A., SAYNOR, R., SCHROEDER, H. G., TAYLOR, D. G. and VEREL, D. (I963). Estimation of blood loss with particular reference to cardiac surgery. British Journal of Anaesthesia, 35, 91-99. TOLDY, M. and SCOTT, D. B. (1969). Blood loss during Caesarean Section under general anaesthesia. British Journal of Anaesthesia, 41 , 868-873. WANGENSTEEN,O. H. (1942). Controlled administration of fluid to surgical patients including description of gravimetric methods of determining status of hydration and blood loss during operation. Minnesota Medicine, 25, 783-789.
COLORIMETRIC E S T I M A T I O N OF B L O O D LOSS D U R I N G S U R G E R Y OF B U R N S
By D. MAHLER,1 M.D. and RUSSELLM. DAVIES, F.F.A.R.C.S. Rayne Fellow in Burns, Mclndoe Memorial Research Unit, Queen Victoria Hospital, East Grinstead, and Senior Consultant Anaesthetist, Queen Victoria Hospital, East Grinstead THERE is a trend today towards earlier excision of burned tissues in an attempt to avoid the onset of severe infections (Sachs and Watson, 1969 ; MacMillan, 197o). One of the problems associated with early excision is massive blood loss, which, unless rapidly and accurately replaced, prejudices the survival of a seriously ill patient. The earliest reference to the measurement of blood loss during operation, which we found, was the paper of Gatch and Little (I924} which described their acid-haematin technique (see below). Since then more and more attention has been paid to the fact that the operative blood loss is often several times greater than the surgeon's estimate (Blain, I929 ; Coller and Maddock, I932 ). Furthermore, no correlation exists between blood loss and changes in haematocrit, haemoglobin and plasma-protein concentrations (Wangensteen, 1942; Crook et al., 1946). It also became apparent that replacement of the blood loss during surgical operations is an essential part of the operation and blood loss requiring transfusion should be anticipated before the body's ability to compensate fails and hypotension develops (Baronofsky et al., 1946 ; Hercus et al., I96I ). The most commonly used methods of determining operative blood loss are gravimetric and volumetric, i.e. the weighing of all swabs and pads before and after use and recording the weight difference and measuring blood aspirated from the operative field. Inaccuracies are due mainly to measuring tissues or fluids other than blood. (Baronofsky et al., 1946 ; Stanton et al., 1949 ; Muir and Grummit, 1954 ; Hercus et al., 1961 ; Jackson, 1962 ; Thornton et al., 1963 ; McIvor, 1967). The circulating blood volume may be calculated by means of dyes or radioactive tracers. The readings cannot be repeated at frequent intervals, however, and the method is only useful for a single reading at a selected time (Thornton et al., 1963 ; Conizaro et al., 1964 ; Mclvor, 1967). The colorimetric method which we have used was first described by Gatch and Little (1924) and was based on the comparison of a standard solution with a solution of acid-haematin made by washing blood-soaked material. It was modified in 1949 by Stanton et al., using a spectrophotometer for greater accuracy and subsequently evolved into a technique based on the haemolysis and dilution of blood in tap water in a simple domestic washing machine (Alsop et al., 1963 ; Rustad, 1963 ; Bond, 1969). The blood loss can be calculated from a series of graphs previously prepared from known dilutions of blood or instruments such as the photoelectric cell of Evans Electroselenium (Roe et al., 1962) and the Perometer (Rustad, 1962) to give direct readings. Other variations of the colorimetric method are the Cyan-Haemoglobin system (Bond, 1969) or direct colorimetric determination of haemoglobin (Perkins and Miller, 1969). 1 D r Mahler, M . D . is seconded f r o m the D e p a r t m e n t of Plastic Surgery, Rarnbam G o v e r n m e n t Hospital, Haifa, Israel. 13 °
COLORIMETRIC ESTIMATION OF BLOOD LOSS DURING SURGERY OF BURNS I3I PRESENT TECHNIQUE The method is based on measuring the haemoglobin lost by the Perometer blood oss monitor 1 which provides a direct reading. During desloughing operations there
-
i
FIG. x. The Perometer, blood loss monitor.
f is unavoidably necrotic debris mixed with the b}6od and separation is essential tor accurate results. After preliminary work with " h o m e - m a d e " equipment a copper filter was fitted to the recirculating line of the Pero~r~eter. This proved wholly effective providing that it was cleaned after each use. x Perometer, A.B. Lars Ljungberg, Sweden.
I32
BRITISH JOURNAL OF PLASTIC SURGERY
The Perometer (Fig. I) consists of a washing machine, into which 4 ° litres of water are introduced together with Perosol, a haemolysing agent. All swabs, pads and linen soaked with blood and any aspirated fluids are collected in the tank (Fig. 2) where
FIG. 2. T h e washing machine section of the Perometer.
:4 FIG. 3.
T h e monitoring unit of the Perometer. T h e button (lower right) is for setting the patient's pre-operative haemoglobin value.
the blood is washed out and haemolysed to oxyhaemoglobin. The solution is circulated continuously from the washing machine via the copper filter through a measuring cell of a photometer, which registers the solution's haemoglobin content. This measuring cell is set at the patient's pre-operative haemoglobin value (Fig. 3), enabling
COLORIMETRIC ESTIMATION OF BLOOD LOSS DURING SURGERY OF BURNS *33 the photometer to register directly the quantities of blood lost by the patient. The photometer responds only to light of the wavelength produced by oxyhaemoglobin and is therefore not affected by the presence of other liquids, dyes or soluble elements. Two scales are available : a low range, which reads 5-600 ml. and a high range which reads up to 5 litres of blood loss. The accuracy measured against known amounts of blood was + ~ - 2 per cent (Toldy and Scott, I969).
RESULTS The technique has been used during 3 i surgical procedures in 18 patients, whose burns varied from 8 to 7° per cent of body surface, mostly full thickness. The age range was from 3 years to 65 years and the range of pre-operative haemoglobin levels was 9"3 g. per cent to I4.6 g. per cent. Surgical intervention consisted of the excision of burned areas and the taking of autografts. The first procedure was carried out from the 5th to 25th day post-burn. Further similar procedures were undertaken as necessary. In our experience the Perometer gives accurate, immediate and continuous monitoring of the blood loss during operation and the speed of intravenous transfusion may, therefore, be continuously regulated. It requires no special skill. It does not need repeated blood sampling or intravenous injections, important points in patients whose veins are at a premium. Potential criticism of the Perometer technique (Bond, I969), i.e. errors of inadequate mixing, incomplete haemolysis, dead spaces in the washing machine or inaccuracy in measurement of water, were found to be minimal as repeated checks with known aliquots of blood of known haemoglobin values showed accuracy up to + 2 per cent. Errors due to the physiological response of the patient during surgery appear to have been overcome by limiting the period of surgery to a maximum of I hour. The main source of error remains the accuracy of the pre-operative haemoglobin measurement which should be made within 24 hours of surgery. Members of the operating team were asked to make subjective estimations of the visible and probable (e.g. from donor sites) blood loss. These varied from over-estimation of 25 per cent to under-estimation up to 75 per cent. The degree of inaccuracy decreased with practice, but clinical estimation of blood loss remained unreliable. The accuracy of the technique imparts confidence in deciding not only whether to transfuse but also how much and at what rate. The aim was to restore the patient's haemoglobin to a minimum of I I g. per cent. I f the level was below this pre-operatively, the deficit was calculated from the estimated blood volume and added to the measured operative blood loss. It is probably also wise to allow for post-operative bleeding from the raw surfaces particularly donor sites. In a few cases this was measured by lysing the dressings on the Ioth day and losses of I5o-25o ml., according to the size of the donor site, were recorded. SUMMARY The Perometer when fitted with a suitable filter is the most satisfactory method available for measuring blood loss during surgery on burned patients. The authors wish to express their thanks to Dr V. Whitmarsh for his work on the preliminary home-made machine; to Mr Hackett for his continuing interest, particularly in his work in determining blood losses into the donor site dressings; to all our surgical colleagues and nursing staff in the Mclndoe Burns Centre; and to Mr P. Broadbery, Chief Medical Photographer at this hospital
134
BRITISH JOURNAL OF PLASTIC SURGERY REFERENCES ALsoI,, W., EMERY, J. L. and ZACIIARY, R. B. (1963). Measurement of blood loss during operation. British Medical Journal, I, 125. BARONOVSKY, I. D., TRELOAr~, A. E. and WANC;ENSXEEN, O. H. (1946). Blood loss in operations : a statistical comparison of losses as determined by the gravimetric and colorimetric methods. Surgery, 20, 761-769. BLAIN, A. (1929). Impressions resulting from 3,ooo transfusions of unmodified blood. Annals of Surgery, 89, 917-922. BOND, A. G. (1969). Determination of operative blood loss. Anaesthesia, 24, 219-229. CANIZARO, P. C., SAWYER, R. B. and SwrrZER, W. E. (I964). Blood loss during excision of third-degree burns. Archives of Surgery, 88, 8o0-802. CULLER, F. A. and MADOOCK, W. G. (1932). Dehydration, attendant on surgical operations. Journal of the American Medical Association, 99, 875-88o. CROOK, C. E., IoB, V. and CULLER, F. A. (1946). Correction of blood loss during surgical operations. Surgery, Gynecology and Obstetrics, 82, 417-422. GATCH, W. D. and LITTLE, W. D. (1924). Amount of blood loss during some of the more common operations. Journal of the American Medical Association, 83, lO75-1o76. HERCUS, V. M., REEVE, T. S., TRACY, G. D. and RUNDLE, F. F. (1961). Blood loss during surgery. British Medical Journal, 2, 1467-1469 . JACKSON, D. (I962). Extensive primary excision and grafting of deep burns, in " Research in Burns ", p. 327 . Philadelphia : F. A. Davies Company. McIvoR, J. (1967). A method of assessing operative and post-operative blood loss. British Journal of Oral Surgery, 5, I-IO. MACMILLAN, B . G . ( I 9 7 0 ). Indications for early excision. Surgical Clinics of North America, 5 ° , 1337-1345. MUIR, I. F. K. and GRUMMIT, M. (1957)- Early excigion of burns with particular reference to blood replacement. " Transactions of the First Congress of the International Society of Plastic Surgery," p. 98, Williams & Wilkins Company. PERKINS, J. B. and MILLER, H. C. (I969). Blood loss during transurethral prostatectomy. Journal of Urology, IOX, 93-97. ROE, C. F., GARDINER, A. J. S. and DUDLEY, H. A. F. (I962). A simple instrument for rapid, continuous determination of operative blood loss. Lancet, I, 672-673. RUSTAD, H. (I963). Measurement of operative blood loss. Acta Chirurgica Seandinavica, 125, 14-18. SACHS, A. and WATSON, J. (I969). Four years' experience at a specialised Burn Centre. Lancet, I, 718-72I. STANTON, J. R., LYON, R. P., FREIS, E. D. and SMIXHWlCK, R. H. (1949). Blood and " available fluid " (thiocyanate) volume studies in surgical patients ; Part I I - - o p e r a tire and post-operative blood loss with particular emphasis upon uncompensated red cell loss. Surgery, Gynecology and Obstetrics, 89, I 8 I - i 9 O. THORNTON, J. A., SAYNOR, R., SCHROEDER, H. G., TAYLOR, D. G. and VEREL, D. (I963). Estimation of blood loss with particular reference to cardiac surgery. British Journal of Anaesthesia, 35, 91-99. TOLDY, M. and SCOTT, D. B. (1969). Blood loss during Caesarean Section under general anaesthesia. British Journal of Anaesthesia, 41 , 868-873. WANGENSTEEN,O. H. (1942). Controlled administration of fluid to surgical patients including description of gravimetric methods of determining status of hydration and blood loss during operation. Minnesota Medicine, 25, 783-789.