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Rationalization of clinical chemistry services in the southern metropolitan region of new south wales
ABSTRACTS OF ANNUAL MEETING
1980 633
(36-48 h), heat stable lactate dehydrogenase (a cardiac specific isoenzyme having slow clearance) was measured if indicated. The predictive value (PV) of the measured enzymes was derived using the discharge diagnosis. PV positive gives the likelihood for the presence of the disease in a patient with a positive result. PV negative estimates the likelihood for freedom of disease in a patient with a negative result. Effectiveness is a measure of the overall diagnostic accuracy of a particular test. Predictive value of
PV positive PV negative Effectiveness
1
CKMB 0.90 1.00 0.99
1
CK 0.91 1.00 0.96
i
AST 0.76 1.00 0.87
1
CK&AST 0.91 1.00 0.87
Routine measurement of isoenzymes on discrete analysers leads to earlier and more accurate diagnosis of MI without increased laboratory costs. USE OF DIGOXIN ASSAYS IN A TEACHING HOSPITAL
S. J. BRYANT, F. BOCHNER & E. DELACEYDepartment of Pathology, Royal Brisbane Hospital This study was designed to determine the way in which plasma digoxin assays were used in a large teaching hospital. Clinical staff were interviewed 48 h after the report left the laboratory and were asked the indication for the investigation, iheir predicted outcome, whether the report had been sighted, how the level of digoxin was interpreted and any change in the management of the patient. Two hundred and eight assays were performed in the 4 wk of the study. Twenty-one inadequate responses and 15 assays performed for other hospitals were not included in the survey. 91036 of requests were on inpatients. The majority of requests (8 1:d) were originated by residents. Suspected toxicity or underdosage were suspected in 36'2, and 35% or requests respectively. When the requesting doctor was confident of his clinical judgement, he was more likely to becorrect if the patient was toxic. The clinical impression of underdosage was often not substantiated. However, 27% of patients in this study had subtherapeutic levels compared with the 12.5% in a study from Melbourne.' It may be that there is a large number of patients taking digoxin, who have subtherapeutic levels and who would not suffer if the drug were ceased. Of47 patients whose results were interpreted as toxic only 19 had plasma digoxin levels above 2.0 pg/l whereas 49 were said to be underdosed when 66 patients had levels less than 1.O pgil. Of the 56 patients who had a change in dose only 17 had a follow-up assay performed. The percentage ofassays which led to a management change (38%) is much greater than that (122,) following the performance of serum protein electrophoresis.' This may reflect the better understanding our medical graduates have of clinical pharmacology than of chemical pathology. References 1. GUEST, K. (1980): Med. J . Ausr. 1, 167-170. 2. BRYANT, S. J. & HICKEY,M. (1980): Aust. N . Z . J . Med. 10, 104106. RATIONALIZATION OF CLINICAL CHEMISTRY SERVICES IN THE SOUTHERN METROPOLITAN REGION OF NEW SOUTH WALES
M. MEERKIN, & L. WYNDHAMDivision of Clinical Chemistry, The Prince of Wales and Prince Henry Hospital Group, Randwick, N . S . W . In 1960 The Prince Henry Hospital, The Prince of Wales Hospital and the Eastern Suburbs Hospital amalgamated as a group of public hospitals to service a large section of the health care needs of the Eastern Suburbs of Sydney. The present bed allocation is 1300 excluding the newly acquired Randwick Chest Hospital. The policy of the Health Commission of N.S.W. and our Boards of Directors has been to rationalize where possible services pertaining to this hospital group. Since the inception of these hospitals there has been a Division of Clinical Chemistry at both Prince Henry and Prince of Wales. In late 1979 the Boards of Directors appointed a new Head of Division of Clinical Chemistry. This was to coincide with the wishes of the Health Commission of N.S.W. that there should be substantial re-equipping and upgrading of the Division. Upgrading of both sites was initially conceived but because of increased costs and
634
ROYAL COLLEGE OF PATHOLOGISTS OF AUSTRALASIA
Pathology (1981), 13, July
stated policy by both the Commission and the Boards of Directors. it was decided that complete rationalization of Clinical Chemistry services was inevitable. Therefore. a submission was placed before the Clinical Directors and the Health Commission through the Regional Director of Health to centralize the Division of Clinical Chemistry at Prince of Wales Hospital. The submission entailed plans for: alterations to the existing facilities at Prince of Wales. (i) (ii) extensions to the laboratory. (iii) substantial re-equipping. (iv) provision for a Division controlled courier service. provision for an adequate computer facility. (v) (vi) upgrading of the present urgent laboratory facility at Prince Henry Hospital, (vii) transfer of all staff t o the Prince of Wales site, and (viii) evaluation of the entire procedure with particular emphasis on future staffing requirements. Discussion will centre around these sections of the submission. DELPHIC-A
NEW COMPREHENSIVE LABORATORY COMPUTER SYSTEM
MICHAEL GIL.L Diagnostic Laborator!,, Bos 5728. Auckland. New Zeuland DELPHIC is a 3rd generation laboratory computer system, handling up to 2000 patients per day. The 1st and 2nd generation systems ran on an IBM I130 and ICL 2903 respectively. DELPHIC is a major conversionldevelopment onto a Burroughs 1800. Major features are: (a) The use of dara base sqftwrire for efficient data handling and to allow access to information immediately after entry. (b) The provision of Visual Display Units (VDU's) in all laboratory departments. Technologists enter and validate their own results and use the VDU to check clinical correlations with results from other departments. In this way. the VDU's provide a communications network linking all areas of the laboratory. (c) The use o f a high-level language (COBOL). text-editing software. and modular design of test validation and format parameters. These facilities make programme modification and development easy-the productivity of our own computer staff has more than doubled. (d) The main frame will accept from minis attached to SMAC. SMA 11, Coulter, etc. (e) A mark-sense card result entry system for Microbiology is being developed.
IMMUNOLOGY AND MICROBIOLOGY SPECIFIC IgM ANTIBODY TESTS IN THE DIAGNOSIS OF CONGENITAL INFECTIONS
P. W. ROBERTSUS & VERAKERTESZ Division of' Microbiologi~.The Prince 01' Wales Hospitnl, Rand~r.ick,N . S . W'. The demonstration of specific IgM antibody in cord or neonawl serum is the most reliable and convenient method of establishing the diagnosis o f the most commonly recognized intrauterine infections. Although the presence of virus haemagglutination inhibiting activity in the IgM fraction of serum indicates the presence of specific IgM antibody in rubella infection, for the recognition of infections caused by those viruses that d o not haemagglutinate, e.g., Cytomegalovirus (CMV) and other micro-organisms. passive haemagglutination, fluorescent or enzymelinked techniques must be used to demonstrate IgM antibody. Fluorescent antibody techniques were claimed to have an advantage in that specific IgM conjugate could be used obviating the need for prior serum fractionation. In practice. however, the presence of rheumatoid factor in serum has been shown to cause non-specific binding to antigen preparations resulting in false positive reactions in this test. In this study to be presented, the results of CMV-specific IgM antibody determinations using the fluorescent antibody (FA) and an enzyme-linked immunosorbent assay (E.I.A.) are compared in a series of 136 infants with clinical characteristics consistent with intrauterine infection. With the CMV-lgM-FA technique positive reactions were obtained in 36 cases when whole serum was used but only 14 of these were positive when the lgM fraction obtained by chromatography was retested. Employing the CMV-IgM-EIA method using whole serum. positive reactions were observed only with the 14 sera which gave positive CMV-lgM-FA reactions with the IgM fraction. The results confirm that false positive reactionscan occur in the CMV-IgM-FA test when whole serum is used and tndicate that the EIA technique is more specific for detecting igM antibody in congenital CMV infection.
1980 633
(36-48 h), heat stable lactate dehydrogenase (a cardiac specific isoenzyme having slow clearance) was measured if indicated. The predictive value (PV) of the measured enzymes was derived using the discharge diagnosis. PV positive gives the likelihood for the presence of the disease in a patient with a positive result. PV negative estimates the likelihood for freedom of disease in a patient with a negative result. Effectiveness is a measure of the overall diagnostic accuracy of a particular test. Predictive value of
PV positive PV negative Effectiveness
1
CKMB 0.90 1.00 0.99
1
CK 0.91 1.00 0.96
i
AST 0.76 1.00 0.87
1
CK&AST 0.91 1.00 0.87
Routine measurement of isoenzymes on discrete analysers leads to earlier and more accurate diagnosis of MI without increased laboratory costs. USE OF DIGOXIN ASSAYS IN A TEACHING HOSPITAL
S. J. BRYANT, F. BOCHNER & E. DELACEYDepartment of Pathology, Royal Brisbane Hospital This study was designed to determine the way in which plasma digoxin assays were used in a large teaching hospital. Clinical staff were interviewed 48 h after the report left the laboratory and were asked the indication for the investigation, iheir predicted outcome, whether the report had been sighted, how the level of digoxin was interpreted and any change in the management of the patient. Two hundred and eight assays were performed in the 4 wk of the study. Twenty-one inadequate responses and 15 assays performed for other hospitals were not included in the survey. 91036 of requests were on inpatients. The majority of requests (8 1:d) were originated by residents. Suspected toxicity or underdosage were suspected in 36'2, and 35% or requests respectively. When the requesting doctor was confident of his clinical judgement, he was more likely to becorrect if the patient was toxic. The clinical impression of underdosage was often not substantiated. However, 27% of patients in this study had subtherapeutic levels compared with the 12.5% in a study from Melbourne.' It may be that there is a large number of patients taking digoxin, who have subtherapeutic levels and who would not suffer if the drug were ceased. Of47 patients whose results were interpreted as toxic only 19 had plasma digoxin levels above 2.0 pg/l whereas 49 were said to be underdosed when 66 patients had levels less than 1.O pgil. Of the 56 patients who had a change in dose only 17 had a follow-up assay performed. The percentage ofassays which led to a management change (38%) is much greater than that (122,) following the performance of serum protein electrophoresis.' This may reflect the better understanding our medical graduates have of clinical pharmacology than of chemical pathology. References 1. GUEST, K. (1980): Med. J . Ausr. 1, 167-170. 2. BRYANT, S. J. & HICKEY,M. (1980): Aust. N . Z . J . Med. 10, 104106. RATIONALIZATION OF CLINICAL CHEMISTRY SERVICES IN THE SOUTHERN METROPOLITAN REGION OF NEW SOUTH WALES
M. MEERKIN, & L. WYNDHAMDivision of Clinical Chemistry, The Prince of Wales and Prince Henry Hospital Group, Randwick, N . S . W . In 1960 The Prince Henry Hospital, The Prince of Wales Hospital and the Eastern Suburbs Hospital amalgamated as a group of public hospitals to service a large section of the health care needs of the Eastern Suburbs of Sydney. The present bed allocation is 1300 excluding the newly acquired Randwick Chest Hospital. The policy of the Health Commission of N.S.W. and our Boards of Directors has been to rationalize where possible services pertaining to this hospital group. Since the inception of these hospitals there has been a Division of Clinical Chemistry at both Prince Henry and Prince of Wales. In late 1979 the Boards of Directors appointed a new Head of Division of Clinical Chemistry. This was to coincide with the wishes of the Health Commission of N.S.W. that there should be substantial re-equipping and upgrading of the Division. Upgrading of both sites was initially conceived but because of increased costs and
634
ROYAL COLLEGE OF PATHOLOGISTS OF AUSTRALASIA
Pathology (1981), 13, July
stated policy by both the Commission and the Boards of Directors. it was decided that complete rationalization of Clinical Chemistry services was inevitable. Therefore. a submission was placed before the Clinical Directors and the Health Commission through the Regional Director of Health to centralize the Division of Clinical Chemistry at Prince of Wales Hospital. The submission entailed plans for: alterations to the existing facilities at Prince of Wales. (i) (ii) extensions to the laboratory. (iii) substantial re-equipping. (iv) provision for a Division controlled courier service. provision for an adequate computer facility. (v) (vi) upgrading of the present urgent laboratory facility at Prince Henry Hospital, (vii) transfer of all staff t o the Prince of Wales site, and (viii) evaluation of the entire procedure with particular emphasis on future staffing requirements. Discussion will centre around these sections of the submission. DELPHIC-A
NEW COMPREHENSIVE LABORATORY COMPUTER SYSTEM
MICHAEL GIL.L Diagnostic Laborator!,, Bos 5728. Auckland. New Zeuland DELPHIC is a 3rd generation laboratory computer system, handling up to 2000 patients per day. The 1st and 2nd generation systems ran on an IBM I130 and ICL 2903 respectively. DELPHIC is a major conversionldevelopment onto a Burroughs 1800. Major features are: (a) The use of dara base sqftwrire for efficient data handling and to allow access to information immediately after entry. (b) The provision of Visual Display Units (VDU's) in all laboratory departments. Technologists enter and validate their own results and use the VDU to check clinical correlations with results from other departments. In this way. the VDU's provide a communications network linking all areas of the laboratory. (c) The use o f a high-level language (COBOL). text-editing software. and modular design of test validation and format parameters. These facilities make programme modification and development easy-the productivity of our own computer staff has more than doubled. (d) The main frame will accept from minis attached to SMAC. SMA 11, Coulter, etc. (e) A mark-sense card result entry system for Microbiology is being developed.
IMMUNOLOGY AND MICROBIOLOGY SPECIFIC IgM ANTIBODY TESTS IN THE DIAGNOSIS OF CONGENITAL INFECTIONS
P. W. ROBERTSUS & VERAKERTESZ Division of' Microbiologi~.The Prince 01' Wales Hospitnl, Rand~r.ick,N . S . W'. The demonstration of specific IgM antibody in cord or neonawl serum is the most reliable and convenient method of establishing the diagnosis o f the most commonly recognized intrauterine infections. Although the presence of virus haemagglutination inhibiting activity in the IgM fraction of serum indicates the presence of specific IgM antibody in rubella infection, for the recognition of infections caused by those viruses that d o not haemagglutinate, e.g., Cytomegalovirus (CMV) and other micro-organisms. passive haemagglutination, fluorescent or enzymelinked techniques must be used to demonstrate IgM antibody. Fluorescent antibody techniques were claimed to have an advantage in that specific IgM conjugate could be used obviating the need for prior serum fractionation. In practice. however, the presence of rheumatoid factor in serum has been shown to cause non-specific binding to antigen preparations resulting in false positive reactions in this test. In this study to be presented, the results of CMV-specific IgM antibody determinations using the fluorescent antibody (FA) and an enzyme-linked immunosorbent assay (E.I.A.) are compared in a series of 136 infants with clinical characteristics consistent with intrauterine infection. With the CMV-lgM-FA technique positive reactions were obtained in 36 cases when whole serum was used but only 14 of these were positive when the lgM fraction obtained by chromatography was retested. Employing the CMV-IgM-EIA method using whole serum. positive reactions were observed only with the 14 sera which gave positive CMV-lgM-FA reactions with the IgM fraction. The results confirm that false positive reactionscan occur in the CMV-IgM-FA test when whole serum is used and tndicate that the EIA technique is more specific for detecting igM antibody in congenital CMV infection.