Clozapine blood level assessment using a point-of-care device: feasibility and reliability.

Background: Therapeutic drug monitoring (TDM) is useful to assess clozapine adherence and optimize treatment. However, analysis of venous blood levels by liquid chromatography tandem mass spectrometry (LC-MS/MS) is often logistically complicated and process time is prolonged. Objective: To assess the feasibility and reliability of a new point-of-care device, (MyCare™ Insite), using capillary blood for clozapine therapeutic monitoring. Methods: Matched venous and capillary blood samples were collected from patients treated with clozapine on a stable dose. Samples were analyzed by LC-MS/MS and MyCare Insite Clozapine Test. Clozapine plasma levels were compared between methods using linear regression model. Both patients and treatment team completed questionnaires about the feasibility of blood sampling. Results: Of the total sample (44 patients, 61% males, mean age 43 ± 12 years), mean daily clozapine dose was 293 ± 134 mg/day. Linear regression model demonstrated high correlation with R 2 = 0.83 (p < 0.0001) and mean difference of 26 ± 162 ng/ml. More than 60% of the patients found the clozapine TDM to be important. Most of the participants (58%) favored the capillary sampling and 11% claimed that testing method would affect their adherence to TDM. Moreover, a larger portion (72%) strongly preferred to be tested at the office rather than at the lab. Conclusions: The point-of-care device offers an accessible and satisfactory measurement of clozapine blood levels. Both patients and healthcare providers reported preference for capillary sampling as well as for the in-office TDM procedure. The immediate results provided by the device can facilitate rapid and informed clinical decisions and therefore improve clozapine treatment outcomes.

Clinics in diagnostic imaging (150)

Spontaneous spinal epidural haematoma is a rarely encountered cause of back pain. It often leads to cauda equina syndrome, necessitating emergency spinal surgery. We report the case of a 19-year-old Chinese man who presented with pain in the lower back, which started after he had carried some heavy boxes. He denied a history of fall or trauma. Magnetic resonance (MR) imaging showed a hyperintense biconvex-shaped lesion in the posterior epidural space on both T1- and T2-weighted sequences, diagnostic of a spinal epidural haematoma. The patient, who was admitted and managed conservatively, had gradual resolution of his pain. No neurological deficit was detected on discharge or on follow-up. Repeat MR imaging showed total resolution of the lumbar spinal epidural haematoma. The clinical characteristics, MR imaging features, diagnosis and management of spontaneous spinal epidural haematoma are discussed.

Clinics in diagnostic imaging (139). Displaced medial meniscus bucket-handle tear

A 58-year-old man presented with knee pain and swelling, following a previous injury. A displaced bucket-handle tear of the medial meniscus was diagnosed on magnetic resonance (MR) imaging and subsequently confirmed by arthroscopy. MR imaging is accurate in diagnosing bucket-handle tears. The different MR imaging signs of bucket-handle tears include the double posterior cruciate ligament sign, displaced fragment in intercondylar notch sign, absent bow-tie sign, anterior flipped meniscus sign and coronal truncation sign. Specificity is increased when a combination of the different imaging signs is present. Understanding the meniscal anatomy and potential mimics of the bucket-handle tear is important in order to ensure an accurate diagnosis and appropriate management.