How valuable is P-wave dispersion in the determination of carboxyhemoglobin levels?

OBJECTIVE: To determine whether or not wave/interval dispersions in electrocardiography (ECG) are increased, and to define whether wave and interval dispersions are correlated with carboxyhemoglobin (COHb) levels. METHODS: ECG, complete blood count, and biochemical parameters were taken from 87 patients with carbon monoxide (CO) poisoning as well as 90 control patients with similar age, gender, and body mass index distribution. COHb levels were recorded in CO-poisoning patients. The COHb levels and the relationships with ECG parameters were studied. RESULTS: Pmax, Pmin, Pd, PRmax, PRmin, PRd, QTmax, QTmin, QTd, cQTmax, cQTmin, cQTd, Tmax, Tmin, and Td in ECG were higher in intoxicated patients than the control group (p < 0.05 for all). Pearson's correlation analyses showed moderately significant positive correlations between COHb level and Pmax (r = 0.224; p = 0.037) and Pd (r = 0.222; p = 0.039). The receiver-operator characteristic (ROC) curve showed that a Pd value of 38 ms determined by ECG separates patients with a COHb ≥ 20% with area under the ROC curve of 0.78 (95%CI = 0.71-0.83), a sensitivity of 67.9% (95%CI = 59.4-75.6), a specificity of 95% (95%CI = 83.0-99.2], a positive predictive value of 97.9% (95%CI = 92.5-99.7), and a negative predictive value of 46.3% (95%CI = 35.3-57.7.) CONCLUSION: A significant increase in wave/interval dispersions in the ECG of CO-poisoning patients compared with controls may show that not only a part is affected but both atrium and the ventricles as a whole are affected by hypoxic ischemia. When COHb levels of the patients are unavailable, P dispersion on ECG may show CO poisoning level of the patient.

Diagnosing isolated nasal fractures in the emergency department: are they missed or overdiagnosed? Ten years experience of 535 forensic cases.

AIM: Nasal bone is the most common broken bone of the face. Incorrect assessments of nasal trauma are frequently encountered in forensic evaluations. Here, we aimed to determine the reasons and frequency of erroneous assessments of nasal trauma in emergency department (ED). METHODS: This is a cross-sectional multicentric study analyzing the Forensic Medical Department archive retrospectively. Epidemiologic features, type of fracture (depressed or non-depressed), and specialty of the doctor examining the cases in ED were studied. Forensic evaluation was reported by analyzing all radiologic examinations (CT and X-ray), medical records, and after repeated physical examination of nasal trauma by the forensic council, consisting of a forensic expert, a radiologist and an otolaryngologist. Nasal fracture was diagnosed when at least two of three physicians agreed. RESULTS: A total of 535 cases (mean age 31.7 ± 14.4, 87.1 % males) were analyzed. The most common causes of injuries were assault (81.8 %), followed by traffic accident (15.3 %) and falls from a height (2.1 %). There were misdiagnoses in ten patients (1.9 %) and overdiagnosis in 135 (24.5 %). The possibility of fracture overdiagnosis was 13.5 times higher than missing it. General practitioners and emergency physicians have 19.7 times (95 % CI 5.5-22. 3) and 3.4 times (95 % CI 1.5-7.8) the tendency to report soft tissue nasal injuries as non-depressed fractures, respectively. CONCLUSION: We found that nasal fractures are rarely missed while the overdiagnosis was very common. Examination of patients by a general practitioner or an emergency physician without consultation with a specialist and using only plain radiographs were found to be independent parameters affecting overdiagnosis.