Band 3, Heft 2

There is an increasing emphasis on using cost-effectiveness analysis to achieve a higher value for the money invested in the healthcare, avoiding waste and unnecessary costs. The process for achieving a better use of available resources should include five steps: collecting data, developing indicators, evaluating evidence, making informed decisions, and considering consequences. Clinical laboratories represent a paradigmatic model to improve data collection in order to develop further steps of the improvement process. Here we describe the experience of the “e-Valuate” project, aiming to improve the collection of laboratory data to provide useful information that should be the foundation for all other steps of this improvement project.

Background : Diagnostic errors are the most common, most costly, and most catastrophic of medical errors. Interdisciplinary teamwork has been shown to reduce harm from therapeutic errors, but sociocultural barriers may impact the engagement of allied health professionals (AHPs) in the diagnostic process. Methods : A qualitative case study of the experience at a single institution around involvement of an AHP in the diagnostic process for acute dizziness and vertigo. We detail five diagnostic error cases in which the input of a physical therapist was central to correct diagnosis. We further describe evolution of the sociocultural milieu at the institution as relates to AHP engagement in diagnosis. Results : Five patients with acute vestibular symptoms were initially misdiagnosed by physicians and then correctly diagnosed based on input from a vestibular physical therapist. These included missed labyrinthine concussion and post-traumatic benign paroxysmal positional vertigo (BPPV); BPPV called gastroenteritis; BPPV called stroke; stroke called BPPV; and multiple sclerosis called BPPV. As a consequence of surfacing these diagnostic errors, initial resistance to physical therapy input to aid medical diagnosis has gradually declined, creating a more collaborative environment for ‘team diagnosis’ of patients with dizziness and vertigo at the institution. Conclusions : Barriers to AHP engagement in ‘team diagnosis’ include sociocultural norms that establish medical diagnosis as something reserved only for physicians. Drawing attention to the valuable diagnostic contributions of AHPs may help facilitate cultural change. Future studies should seek to measure diagnostic safety culture and then implement proven strategies to breakdown sociocultural barriers that inhibit effective teamwork and transdisciplinary diagnosis.

An analysis of 50 clinicopathologic conferences (CPCs) reveals the method of diagnosis in them to consist of construction of exhaustive differential diagnosis followed by evaluation of each disease in it by the likelihood inference approach. This method leads to 98% diagnostic accuracy in these CPCs. A probabilistic approach is found not to be employed for evaluation of a disease.

Background : Diagnostic errors causing harm in children are understudied, resulting in a knowledge gap regarding pediatricians’ interest in reducing their incidence. Methods : Electronic survey of general pediatricians focusing on diagnostic error incidence, errors they were interested in trying to improve, and errors reduced by their electronic health record (EHR). Results : Of 300 contacted pediatricians, 77 (26%) responded, 58 (19%) served ambulatory patients, and 48 (16%) completed the entire questionnaire. Of these 48, 17 (35%) reported making a diagnostic error at least monthly, and 16 (33%) reported making a diagnostic error resulting in an adverse event at least annually. Pediatricians were “most” interested in “trying to improve” missed diagnosis of hypertension (17%), delayed diagnosis due to missed subspecialty referral (15%), and errors associated with delayed follow-up of abnormal laboratory values (13%). Among the 44 pediatricians with an EHR, 16 (36%) said it reduced the likelihood of missing obesity and 14 (32%) said it reduced the likelihood of missing hypertension. Also, 15 (34%) said it helped avoid delays in follow-up of abnormal laboratory values. A third (36%) reported no help in diagnostic error reduction from their EHR. Conclusions : Pediatricians self-report an appreciable number of diagnostic errors and were most interested in preventing high frequency, non-life-threatening errors. There exists a need to leverage EHRs to support error reduction efforts.

Background: Several factors that can lead to falsely elevated values of serum. Thrombocytosis is one of these factors, since breakage or activation of platelets during blood coagulation in vitro may lead to spurious release of potassium. The purpose of the study was to evaluate to which extent the platelet count may impact on potassium in both serum and plasma. Methods: The study population consisted of 42 subjects with platelets values comprised between 20 and 750×10 9 /L. In each sample potassium was measured in both serum and plasma using potentiometric indirect method on the analyzer Modular P800 (Roche, Milan, Italy). Platelet count was performed with the hematological analyzer Advia 120 (Siemens, Milano, Italy). Results: Significant differences were found between potassium values in serum and in plasma. A significant correlation was also observed between serum potassium values and the platelet count in whole blood, but not with the age, sex, erythrocyte and leukocyte counts in whole blood. No similar correlation was noticed between plasma potassium and platelet count in whole blood. The frequency of hyperkalemia was also found to be higher in serum (20%) than in plasma (7%) in samples with a platelet count in whole blood >450×10 9 /L. Conclusions: The results of this study show that platelets in the biological samples may impact on potassium measurement when exceeding 450×10 9 /L. We henceforth suggest that potassium measurement in plasma may be more accurate than in serum, especially in subjects with thrombocytosis.

Background: The effect of radiofrequency exposure on human health and health care equipment is a matter of ongoing debate. This study was planned to investigate the influence of radiofrequency (RF) waves emitted by a commercial mobile phone on red blood cells (RBC) in vitro. Methods: The study population consisted of 16 ostensibly healthy volunteers. Two whole blood specimens were collected from each volunteer. One sample was placed in a plastic rack, 1 cm distant from the chassis of a commercial mobile phone which was activated by a remote phone call lasting 30 min. The other blood sample was placed in another plastic rack, but was kept distant from any type of RF source. The main RBC parameters including RBC count, hematocrit (Ht), hemoglobin, mean corpuscular platelet volume (MPV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC) and RBC distribution width (RDW-CV) were assessed with an Advia 2120. Results: The exposure of whole blood to the mobile phone call significantly increased Ht, hemoglobin, MCV and MCH, whereas the RBC count, MCHC and RDW-CV remained unchanged. A significant correlation was observed between variation of Ht and those of hemoglobin (p=0.008), MCV (p=0.009) or MCH (p=0.037), as well as between hemoglobin and MCV (p=0.048). Increased values were found in 13/16 (81%) samples for both Ht and hemoglobin, 14/16 (88%) samples for MCH and 16/16 (100%) samples for MCV. Conclusions: These results suggest that close mobile phone exposure may be an unappreciated and possibly underestimated cause of preanalytical bias in RBC testing.

Osmotic demyelination syndrome (ODS), previously known as central pontine myelinolysis, is a rare neurological condition characterized by demyelination of the pons or extrapontine areas including the midbrain, thalamus, basal nuclei, and cerebellum, resulting in upper motor neuron dysfunction and pseudobulbar palsy. We report a case of a 45-year-old woman with a history of alcohol dependence and end stage liver disease complicated by hepatic encephalopathy who developed symptoms suspicious of recurrent hepatic encephalopathy and experienced a generalized seizure during an inpatient stay. After 10 days of treatment with no improvement, it was noted that the patient had locked-in syndrome and that her sodium levels had rapidly risen 2 days prior. This led to a clinical suspicion of ODS, which was confirmed on T2-weighted MRI and subsequently on autopsy. In this clinical vignette, we review the clinical presentation, prognosis, and diagnostic considerations of ODS.

Ovarian torsion is often a diagnosis of exclusion, and while less common in pre-pubertal females, it is on the differential for a pelvic mass. Tumor markers can be used to characterize a pelvic mass, with varying sensitivity and specificity. This is a case of a 10-year-old pre-pubertal female presenting with abdominal pain and found to have an ovarian mass. Her tumor markers demonstrated an elevated CA-125, increasing concern for neoplasm. This led to a delayed operative course and she was ultimately found to have an ovarian torsion. There is unclear utility of CA-125 in pediatrics and reliance on tumor markers during the work-up of an ovarian mass should be limited to avoid diagnostic error.