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Meconium testing for diagnosis of intra-uterine cocaine or opiate exposure
9TH INTERNATIONAL/6TH EUROPEAN JOINT SYMPOSIUM ON PURINE AND PYRIMIDINE METABOLISM IN MAN 20% TCA solution removed detectable levels of proteins, and did not affect the measurement of uric acid. Second, protein-free supernatants from IgM containing samples were measured by the OM and compared with the corresponding serum samples measured by the MM. There was good correlation between the two methods (r = 0.945), and no statistical difference between the means using a paired t-test. Conclusion The modified method is satisfactory for routine analysis of samples, including those with IgM paraproteins.
Results Over 200 samples were compared visually and spectrophotometrically. Seventy CSF samples were assessed quantitatively. Forty two samples had no measurable bilirubin; in 25 CSF bilirubin concentrations were <0.45 umol/L. The three samples with bilirubin concentrations of 0.45 umol/L or greater were visually xanthochromatic. Conclusions Spectrophotometric assessment has the advantage of objectivity but to date has not confirmed additional SAH. Clinical evaluation and comparison studies are continuing.
TOXICOLOGY AND DRUGS OF ABUSE 40. 38.
MONITORING INTRAVENOUS LIPID INFUSIONS IN NEONATES: TRIGLYCERIDES VS TURBIDITY
Halstead, A.C. 1, Ling, E.W. 2, Albersheim, S.G. 2, and Tsai, M. 1, Departments of Pathology 1 and Pediatrics 2, B.C.'s Children's Hospital, 4480 Oak St., Vancouver, B.C. V6H 3V4, Canada
Young Tai, KF. W. and Collier, C.P., Dept. of Paediatrics and Pathology, Queen's University and Kingston General Hospital, 76 Stuart St., Kingston, Ont., K7L 2V7, Canada Objectives As most of the studies on measuring turbidity for this purpose were done 20 years ago, we have revisited the correlation between triglycerides (TRIG) and turbidity (TBD); and have performed an informal survey of current practises in laboratories that service neonatal intensive care units. Methods For 6 months in 1996, we analysed TBD (by spectrophotometry, 600 nm) and TRIG (PARAMAX, not blanked for glycerol) in 312 samples from 55 neonates receiving total parenteral nutrition (5-10% glucose, Vamin amino acid solution and 20% Intralipid) as a constant 24 hour infusion. The survey was sent by FAX in Canada, and by listserv (ACB, UK) internationally. Results Both the TRIG (0.6-2.3 mM) and the TBD (<1.2 g/L) results were normal in 289 samples; 7 had both results elevated; 7 had elevated TRIGs only; and 9 had elevated TBDs only. No clinical cause (eg. infection) was identified for the discordant results. Serum TBD was quantified in 3/6 labs in Canada (2 by spectrophotometry, 1 by nephelometry); but not in any of the 6 labs outside Canada. TBD was estimated visually by 3 labs (one in Canada; 2 internationally). Conclusions TRIG and TBD results correlated 95% of the time using our current methodologies. TBD was measured by only 50% of surveyed labs (6/12): this test, and its literature, needs to be reviewed based on today's clinical protocols and laboratory procedures.
39.
XANTHOCHROMIA: VISUAL OR SPECTROPHOTOMETRIC A S S E S S M E N T Tesanovic, M~ Gibb, AP., Croft, J., Sutherland, G., and Haydon, C., Calgary Laboratory Services, Foothills Hospital, Calgary, Alberta T2N 2T9
Timely diagnosis of sub-arachnoid hemorrhage (SAH) is of utmost importance for patient management and outcome. A negative CT scan is followed by lumbar puncture in patients with history of suspected SAH. Yellow coloration or xanthochromia of cerebrospinal fluid (CSF) may indicate hemoglobin and/or bilirubin. Objectives To compare visual/spectrophotometric assessment and to investigate whether the latter is a more sensitive and specific test for detection of SAH. Methods After centrifugation the CSF were visually examined for xanthochromia. The same specimens were scanned at 350-700 nm and evaluated for the presence of hemoglobin, ilirubin and other chromogens. Absorbances, delta absorbance and derivative spectras were recorded and used for quantitation as needed. 378
MECONIUM TESTING FOR DIAGNOSIS OF INTRA-UTERINE COCAINE OR OPIATE EXPOSURE
Detection of drug use in pregnancy is important for management of mother and newborn. Meconium, which forms after 16 weeks pregnancy, has been proposed as a good sample to test for drugs. Objective To evaluate radio immunoassay (RIA) screening for cocaine and morphine in meconium, followed by gas chromatography/mass spectrometry (GC/MS) confirmation, as a technique for detecting intra-uterine drug exposure. Methods Meconium was collected from three groups of infants: a) 27 infants of non-drug using mothers and 25 infants of mothers reporting drug use in pregnancy, b) 519 randomly selected infants and c) 467 infants whose mothers consented to provide information about drug use during pregnancy. RIA for cocaine metabolite and serum morphine (Coat-A-Count, DPC) was performed as previously reported (Clin Biochem 1995; 28:335). Samples with cocaine metabolite reactivity 50 ng/g or morphine reactivity 20 ng/g were analysed by GC/MS (Riverview Hospital). GC/MS detected cocaine, benzoyl ecgonine, codeine and morphine 5 ng/g meconium. Results In group a), RIA identified 19/25 samples for cocaine and 9/25 for morphine confirmation. GC/MS confirmed 65% of cocaine and all the morphine "positives". In randomly screened infants RIA detected cocaine in 35 (6.7% and morphine in 20 (3.9%). GC/MS confirmed 3/25 (12%) cocaine and 9/17 (53%) morphine samples with sufficient meconium. In the consenting group, of 16 cocaine and 6 morphine "positives" by RIA, GC/MS confirmed 1/12 (8%) cocaine and 5/6 (83%) morphine samples. Conclusions RIA followed by GC/MS identified intra-uterine opiate exposure. The low confirmation rate for cocaine, however, suggests that specificity of the RIA method and development of GC/MS methods for other cocaine metabolites must be investigated before reliable meconium screening for cocaine can be implemented.
41.
MARKERS OF URINE T A M P E R I N G - - D E T E C TION OF SAMPLE TAMPERING IN AN OPIATE DEPENDENCY PROGRAM Kapur, B. M, Hershkop, S. and Koren, G. Div. of Clin. Pharm. and Toxicology, The Hospital for Sick Children, 555 University Ave, Toronto ON. M5G 1X8 Canada; The Depts. Of Clinical Biochemistry and Pharmacology, University of Toronto, and Daniel Medical Laboratories (MedChem Laboratories).
Patients are known to add adulterants or may resubmit urine samples to avoid detection of drug use. We report here a reevalCLINICAL BIOCHEMISTRY, VOLUME 30, J U N E 1997
Results Over 200 samples were compared visually and spectrophotometrically. Seventy CSF samples were assessed quantitatively. Forty two samples had no measurable bilirubin; in 25 CSF bilirubin concentrations were <0.45 umol/L. The three samples with bilirubin concentrations of 0.45 umol/L or greater were visually xanthochromatic. Conclusions Spectrophotometric assessment has the advantage of objectivity but to date has not confirmed additional SAH. Clinical evaluation and comparison studies are continuing.
TOXICOLOGY AND DRUGS OF ABUSE 40. 38.
MONITORING INTRAVENOUS LIPID INFUSIONS IN NEONATES: TRIGLYCERIDES VS TURBIDITY
Halstead, A.C. 1, Ling, E.W. 2, Albersheim, S.G. 2, and Tsai, M. 1, Departments of Pathology 1 and Pediatrics 2, B.C.'s Children's Hospital, 4480 Oak St., Vancouver, B.C. V6H 3V4, Canada
Young Tai, KF. W. and Collier, C.P., Dept. of Paediatrics and Pathology, Queen's University and Kingston General Hospital, 76 Stuart St., Kingston, Ont., K7L 2V7, Canada Objectives As most of the studies on measuring turbidity for this purpose were done 20 years ago, we have revisited the correlation between triglycerides (TRIG) and turbidity (TBD); and have performed an informal survey of current practises in laboratories that service neonatal intensive care units. Methods For 6 months in 1996, we analysed TBD (by spectrophotometry, 600 nm) and TRIG (PARAMAX, not blanked for glycerol) in 312 samples from 55 neonates receiving total parenteral nutrition (5-10% glucose, Vamin amino acid solution and 20% Intralipid) as a constant 24 hour infusion. The survey was sent by FAX in Canada, and by listserv (ACB, UK) internationally. Results Both the TRIG (0.6-2.3 mM) and the TBD (<1.2 g/L) results were normal in 289 samples; 7 had both results elevated; 7 had elevated TRIGs only; and 9 had elevated TBDs only. No clinical cause (eg. infection) was identified for the discordant results. Serum TBD was quantified in 3/6 labs in Canada (2 by spectrophotometry, 1 by nephelometry); but not in any of the 6 labs outside Canada. TBD was estimated visually by 3 labs (one in Canada; 2 internationally). Conclusions TRIG and TBD results correlated 95% of the time using our current methodologies. TBD was measured by only 50% of surveyed labs (6/12): this test, and its literature, needs to be reviewed based on today's clinical protocols and laboratory procedures.
39.
XANTHOCHROMIA: VISUAL OR SPECTROPHOTOMETRIC A S S E S S M E N T Tesanovic, M~ Gibb, AP., Croft, J., Sutherland, G., and Haydon, C., Calgary Laboratory Services, Foothills Hospital, Calgary, Alberta T2N 2T9
Timely diagnosis of sub-arachnoid hemorrhage (SAH) is of utmost importance for patient management and outcome. A negative CT scan is followed by lumbar puncture in patients with history of suspected SAH. Yellow coloration or xanthochromia of cerebrospinal fluid (CSF) may indicate hemoglobin and/or bilirubin. Objectives To compare visual/spectrophotometric assessment and to investigate whether the latter is a more sensitive and specific test for detection of SAH. Methods After centrifugation the CSF were visually examined for xanthochromia. The same specimens were scanned at 350-700 nm and evaluated for the presence of hemoglobin, ilirubin and other chromogens. Absorbances, delta absorbance and derivative spectras were recorded and used for quantitation as needed. 378
MECONIUM TESTING FOR DIAGNOSIS OF INTRA-UTERINE COCAINE OR OPIATE EXPOSURE
Detection of drug use in pregnancy is important for management of mother and newborn. Meconium, which forms after 16 weeks pregnancy, has been proposed as a good sample to test for drugs. Objective To evaluate radio immunoassay (RIA) screening for cocaine and morphine in meconium, followed by gas chromatography/mass spectrometry (GC/MS) confirmation, as a technique for detecting intra-uterine drug exposure. Methods Meconium was collected from three groups of infants: a) 27 infants of non-drug using mothers and 25 infants of mothers reporting drug use in pregnancy, b) 519 randomly selected infants and c) 467 infants whose mothers consented to provide information about drug use during pregnancy. RIA for cocaine metabolite and serum morphine (Coat-A-Count, DPC) was performed as previously reported (Clin Biochem 1995; 28:335). Samples with cocaine metabolite reactivity 50 ng/g or morphine reactivity 20 ng/g were analysed by GC/MS (Riverview Hospital). GC/MS detected cocaine, benzoyl ecgonine, codeine and morphine 5 ng/g meconium. Results In group a), RIA identified 19/25 samples for cocaine and 9/25 for morphine confirmation. GC/MS confirmed 65% of cocaine and all the morphine "positives". In randomly screened infants RIA detected cocaine in 35 (6.7% and morphine in 20 (3.9%). GC/MS confirmed 3/25 (12%) cocaine and 9/17 (53%) morphine samples with sufficient meconium. In the consenting group, of 16 cocaine and 6 morphine "positives" by RIA, GC/MS confirmed 1/12 (8%) cocaine and 5/6 (83%) morphine samples. Conclusions RIA followed by GC/MS identified intra-uterine opiate exposure. The low confirmation rate for cocaine, however, suggests that specificity of the RIA method and development of GC/MS methods for other cocaine metabolites must be investigated before reliable meconium screening for cocaine can be implemented.
41.
MARKERS OF URINE T A M P E R I N G - - D E T E C TION OF SAMPLE TAMPERING IN AN OPIATE DEPENDENCY PROGRAM Kapur, B. M, Hershkop, S. and Koren, G. Div. of Clin. Pharm. and Toxicology, The Hospital for Sick Children, 555 University Ave, Toronto ON. M5G 1X8 Canada; The Depts. Of Clinical Biochemistry and Pharmacology, University of Toronto, and Daniel Medical Laboratories (MedChem Laboratories).
Patients are known to add adulterants or may resubmit urine samples to avoid detection of drug use. We report here a reevalCLINICAL BIOCHEMISTRY, VOLUME 30, J U N E 1997