Faculty Bibliography

BACKGROUND: Electronic order-sets increasingly ask clinicians to answer questions or follow algorithms. Cooperation with such requests has not been studied. SETTING: Internal Medicine service of an academic medical center. OBJECTIVE: We studied the accuracy of clinician responses to questions embedded in electronic admission and discharge order-sets. Embedded questions asked whether any of three "core" diagnoses was present; a response was required to submit orders. Endorsement of any diagnosis made available best-practice ordering screens for that diagnosis. DESIGN: Three reviewers examined 180 electronic records (8% of discharges), drawn equally (for each core diagnosis) from possible combinations of Yes/No responses on admission and discharge. In addition to noting responses, we identified whether the core diagnosis was coded, determined from notes whether the admitting clinician believed that diagnosis present, and sought clinical evidence of disease on admission. We also surveyed participating clinicians anonymously about practices in answering embedded questions. MEASUREMENTS: We measured occurrence of six admission and five discharge scenarios relating medical record evidence of disease to clinician responses about its presence. RESULTS: The commonest discordant pattern between response and evidence was a negative response to disease presence on admission despite both early clinical evidence and documentation. Survey of study clinicians found that 75% endorsed some intentional inaccuracy; the commonest reason given was that questions were sometimes irrelevant to the clinical situation at the point asked. CONCLUSION: Through faults in order-set design, limitations of software, and/or because of an inherent tendency to resist directed behavior, clinicians may often ignore questions embedded in order-sets.

We demonstrated recently that uninjured C-fiber nociceptors in the L4 spinal nerve develop spontaneous activity after transection of the L5 spinal nerve. We postulated that Wallerian degeneration leads to an alteration in the properties of the neighboring, uninjured afferents from adjacent spinal nerves. To explore the role of degeneration of myelinated versus unmyelinated fibers, we investigated the effects of an L5 ventral rhizotomy in rat. This lesion leads to degeneration predominantly in myelinated fibers. Mechanical paw-withdrawal thresholds were assessed with von Frey hairs, and teased-fiber techniques were used to record from single C-fiber afferents in the L4 spinal nerve. Behavioral and electrophysiological data were collected in a blinded manner. Seven days after surgery, a marked decrease in withdrawal thresholds was observed after the ventral rhizotomy but not after the sham operation. Single fiber recordings revealed low-frequency spontaneous activity in 25% of the C-fiber afferents 8-10 d after the lesion compared with only 11% after sham operation. Paw-withdrawal thresholds were inversely correlated with the incidence of spontaneous activity in high-threshold C-fiber afferents. In normal animals, low-frequency electrocutaneous stimulation at C-fiber, but not A-fiber, strength produced behavioral signs of secondary mechanical hyperalgesia on the paw. These results suggest that degeneration in myelinated efferent fibers is sufficient to induce spontaneous activity in C-fiber afferents and behavioral signs of mechanical hyperalgesia. Ectopic spontaneous activity from injured afferents was not required for the development of the neuropathic pain behavior. These results provide additional evidence for a role of Wallerian degeneration in neuropathic pain.