Assessment of Utility of Urine Reagent Strips for Analysis of Cerebrospinal Fluid (CSF) In Emergency Settings for Rapid Clinical Interventions

Abstract

                  Meningitis is an emergency condition, requiring timely diagnosis and prompt clinical intervention. Alacritous availability of reasonably, sound laboratorial setup required for CSF analysis is many times not possible in most small healthcare setups. Urine reagent strips are cheap, easily available and provide rapid analysis of urine samples. These urine reagent strips if found unerring can be utilised for rapid bedside analysis of CSF for provisional diagnosis and initiation of treatment. We have undertaken this study, for assessing the of utility of urine reagent strips in analysis of CSF leucocytes, proteins and glucose and enhance the available evidence for its imbibition in routine clinical practices

Material and methods-

                  This observational study was done in AVBRH, Sawangi Meghe, SMHRC and Clinical Laboratory division of Department of Pathology DMMC, Wanadongri, Hingna, Nagpur, over a duration of 1 year. A total 100 CSF samples were analysed for Urine protein, glucose and leucocyte counts, using Urine reagent strips bedside and routine biochemical and microscopic investigations were carried out within one hour. Mission expert urinalysis strips were used for index test and Routine biochemistry and microscopy was used as reference test.

RESULTS-

                  Among the 100 CSF samples of suspected meningitis analysed, male: female ratio was 1.2:1. The sensitivity, specificity and accuracy for leucocyte estimation were 95.95% (71 of 74), 96.15% (25 of 26) and 96.00%. respectively. CSF proteins had sensitivity of 97.29(72 of 74) at +1(<30mg/dl) of urine reagent strips but specificity at +1 was low i.e., 69.23% (18 of 26), which rose to 96.1% (25 of 26) when cut off was kept as +2 (i.e., >100 mg/ dl) in urine reagent strips. The accuracy attained was 90.00%. at cut-off +1 and 97.00% at cut-off +2. The sensitivity for glucose at detecting low glucose levels in CSF on urine reagent strips score 0 i.e., <50 mg/dl is 91.18% (68/74) and specificity is 65.3% (17/26). The accuracy attained was 85%.

Conclusion-

                  Urine reagent strips can be utilised for testing of CSF for proteins, glucose and granulocytes as a point of care, bedside test. Using a higher cut-off for Proteins improves the specificity and accuracy. Also due to difference between normal range of glucose in urine and CSF the accuracy and specificity for analysis of glucose in CSF is low. Reagent strips specifically designed for CSF and standardised as per normal and diagnostic ranges of granulocytes, glucose and proteins in CSF should be made, which will have better sensitivity, specificity and accuracy and will also be cost effective.