An Analysis of Reference Laboratory Testing in a Large Urban Academic Medical Center: The Impact of New Molecular Diagnostic Technologies

Early Neurophysiological Monitoring of Train of Four Assists in the Detection of Pseudocholinesterase Deficiency

A craniotomy with cortical and subcortical mapping was planned for a 64-year-old male with a large right frontotemporal brain mass. Total intravenous anesthesia was performed, and 200 milligrams of succinylcholine was administered at induction. A train of four prior to head pinning (52 minutes after succinylcholine administration) revealed zero of four twitches in the left hand and foot. The patient did not regain spontaneous breathing despite discontinuation of infusions and the surgeon canceled the case at 108 minutes from induction. The patient was safely extubated at 270 minutes. Pseudocholinesterase deficiency was suspected, and labs revealed that the patient was outside of the normal range for pseudocholinesterase enzyme at 698 units/L with a dibucaine inhibition number of 40. The patient's procedure was rescheduled 2 days later, and neuromuscular blockade was avoided. The procedure went ahead as planned with successful mapping and monitoring. This case highlights the effect of pseudocholinesterase deficiency on neuromonitoring and the importance of running train of four early on to detect neuromuscular junction issues in high-risk procedures. In this case, the surgeon was able to avoid pinning and positioning the patient and rescheduled the procedure so that motor mapping, direct cortical motor evoked potentials, and transcranial motor evoked potentials could be successfully performed.

A Generalizable Decision-Making Framework for Selecting Onsite versus Send-out Clinical Laboratory Testing

BACKGROUND

Laboratory networks provide services through onsite testing or through specimen transport to higher-tier laboratories. This decision is based on the interplay of testing characteristics, treatment characteristics, and epidemiological characteristics.

OBJECTIVES

Our objective was to develop a generalizable model using the threshold approach to medical decision making to inform test placement decisions.

METHODS

We developed a decision model to compare the incremental utility of onsite versus send-out testing for clinical purposes. We then performed Monte Carlo simulations to identify the settings under which each strategy would be preferred. Tuberculosis was modeled as an exemplar.

RESULTS

The most important determinants of the decision to test onsite versus send-out were the clinical utility lost due to send-out testing delays and the accuracy decrement with onsite testing. When the sensitivity decrements of onsite testing were minimal, onsite testing tended to be preferred when send-out delays reduced clinical utility by >20%. By contrast, when onsite testing incurred large reductions in sensitivity, onsite testing tended to be preferred when utility lost due to delays was >50%. The relative cost of onsite versus send-out testing affected these thresholds, particularly when testing costs were >10% of treatment costs.

CONCLUSIONS

Decision makers can select onsite versus send-out testing in an evidence-based fashion using estimates of the percentage of clinical utility lost due to send-out delays and the relative accuracy of onsite versus send-out testing. This model is designed to be generalizable to a wide variety of use cases.

HIGHLIGHTS

The design of laboratory networks, including the decision to place diagnostic instruments at the point-of-care or at higher tiers as accessed through specimen transport, can be informed using the threshold approach to medical decision making.The most important determinants of the decision to test onsite versus send-out were the clinical utility lost due to send-out testing delays and the accuracy decrement with onsite testing.The threshold approach to medical decision making can be used to compare point-of-care testing accuracy decrements with the lost utility of treatment due to send-out testing delays.The relative cost of onsite versus send-out testing affected these thresholds, particularly when testing costs were >10% of treatment costs.

Utilization management in a large urban academic medical center: a 10-year experience

Management of laboratory test utilization presents an ongoing challenge. Most studies reported in the literature have described efforts to control one or a few tests, but the results cannot be generalized to a broader utilization management strategy. Herein we report our experiences with an organizational utilization management program during a 10-year period. Cumulatively, our program has achieved significant success, saving millions of dollars in blood components and reducing inpatient tests per discharge by 26%. Highlights from our experiences include the importance of implementing an institutional organizational structure to support utilization management, the central role fulfilled by clinical pathologists as leaders of the program, the ability to obtain timely utilization data, and careful selection of the most appropriate implementation tools tailored to the unique circumstances of each utilization management initiative.

Molecular diagnostic testing in malignant gliomas: a practical update on predictive markers

Advances in understanding the molecular underpinnings of cancer and in molecular diagnostic technologies have changed the clinical practice of oncologic pathology. The development of targeted therapies against specific molecular alterations in cancer further portends changes in the role of the pathology laboratory to guide such custom therapies. To reconcile the flood of scientific discoveries in this area, the promises of highly touted novel therapeutics, and the practicality of applying this knowledge to the day-to-day practice of clinical neuropathology, the present review highlights the operative differences between diagnostic, predictive, and prognostic markers, and discusses issues surrounding the transition of prospective biomarkers to routine laboratory implementation. This review focuses on 3 predictive molecular markers that are either in clinical use or are contemplated for use in the evaluation of malignant gliomas: assessment of 1p/19q loss in oligodendroglial tumors, examination of O6-methylguanine DNA methyltransferase promoter methylation status in glioblastomas, and molecular dissection of the epidermal growth factor receptor-phosphatidylinositol 3-kinase pathway in glioblastomas. Implementation of such predictive markers is not straightforward and requires critical review of the available literature and attention to practical laboratory, compliance, financial, and clinical management issues.