High dose vitamin C induced methemoglobinemia and hemolytic anemia in glucose-6-phosphate dehydrogenase deficiency.

Investigational use of intravenous vitamin C has been on the rise, but its side effects may be underreported. A 75-year-old woman presented with acute onset of jaundice, dark urine and shortness of breath after receiving 30 g of vitamin C infusion as an unconventional therapy for her hemifacial spasm. Diagnosis of methemoglobinemia and hemolytic anemia was made clinically and confirmed on laboratory tests. She recovered with supportive treatment and packed cell transfusion. Her previously unrecognised underlying condition of glucose-6-phosphate dehydrogenase (G6PD) deficiency was confirmed months after the initial presentation. This is the first reported case of methemoglobinemia and hemolytic anemia induced by high dose vitamin C in a female patient with G6PD deficiency. The dosage of vitamin C administered was also relatively low compared with previous adult reports. When administered at physiological dose, vitamin C can be used as an alternative to methylene blue in treatment of methemoglobinemia in patients with G6PD deficiency. However at supraphysiological dose vitamin C can paradoxically lead to hemolytic anemia in the same group of patients. Physicians should be alert of these potential complications of high dose vitamin C.

Visualization of the inferoposterior thoracic wall (VIP) and boomerang signs-novel sonographic signs of right pleural effusion.

OBJECTIVES: This study is to present the diagnostic values of the novel sonographic visualization of the inferoposterior thoracic wall (VIP) and boomerang signs in detecting right pleural effusion by sonologists with little to no experience in ultrasound. METHODS: A prospective analysis of a convenience sample of patients who were assessed by junior intensive care physicians was performed. The patients all underwent computed tomography (CT) of the chest or abdomen with lung bases as part of their care regardless of indication; the results were interpreted by radiologists and were considered the gold standard. Sonography was performed to assess for the presence of the VIP and boomerang signs. Sonographic and chest radiographic findings were compared against CT results. RESULTS: 73 patients were enrolled. The sensitivity and specificity for the VIP sign were 0.85 (95% confidence interval [CI], 0.67-0.94) and 0.86 (95% CI, 0.70-0.95). The sensitivity and specificity for the boomerang sign were 0.78 (95% CI, 0.60-0.90) and 0.87 (95% CI, 0.71-0.95). However, the sensitivity and specificity for the traditional approach of detecting an anechoic collection above the diaphragm to indicate pleural effusion were only 0.54 (95% CI, 0.37-0.71) and 0.86 (95% CI, 0.80-0.99). CONCLUSIONS: Despite inexperience in sonography, the novel VIP and boomerang signs show high diagnostic values in detecting right pleural effusion compared to the traditional methods.

Make it SIMPLE: enhanced shock management by focused cardiac ultrasound.

BACKGROUND: Shock is a spectrum of circulatory failure that, if not properly managed, would lead to high mortality. Special diagnostic and treatment strategies are essential to save lives. However, clinical and laboratory findings are always non-specific, resulting in clinical dilemmas. MAIN CONTENT: Focused cardiac ultrasound (FoCUS) has emerged as one of the power tools for clinicians to answer simple clinical questions and guide subsequent management in hypotensive patients. This article will review the development and utility of FoCUS in different types of shock. The sonographic features and ultrasound enhanced management of hypotensive patients by a de novo "SIMPLE" approach will be described. Current evidence on FoCUS will also be reviewed. CONCLUSION: Focused cardiac ultrasound provides timely and valuable information for the evaluation of shock. It helps to improve the diagnostic accuracy, narrow the possible differential diagnoses, and guide specific management. SIMPLE is an easy-to-remember mnemonic for non-cardiologists or novice clinical sonographers to apply FoCUS and interpret the specific sonographic findings when evaluating patients in shock.

Lung ultrasound imaging in avian influenza A (H7N9) respiratory failure.

BACKGROUND: Lung ultrasound has been shown to identify in real-time, various pathologies of the lung such as pneumonia, viral pneumonia, and acute respiratory distress syndrome (ARDS). Lung ultrasound maybe a first-line alternative to chest X-ray and CT scan in critically ill patients with respiratory failure. We describe the use of lung ultrasound imaging and findings in two cases of severe respiratory failure from avian influenza A (H7N9) infection. METHODS: Serial lung ultrasound images and video from two cases of H7N9 respiratory failure requiring mechanical ventilation and extracorporeal membrane oxygenation in a tertiary care intensive care unit were analyzed for characteristic lung ultrasound findings described previously for respiratory failure and infection. These findings were followed serially, correlated with clinical course and chest X-ray. RESULTS: IN BOTH PATIENTS, CHARACTERISTIC LUNG ULTRASOUND FINDINGS HAVE BEEN OBSERVED AS PREVIOUSLY DESCRIBED IN VIRAL PULMONARY INFECTIONS: subpleural consolidations associated or not with local pleural effusion. In addition, numerous, confluent, or coalescing B-lines leading to 'white lung' with corresponding pleural line thickening are associated with ARDS. Extension or reduction of lesions observed with ultrasound was also correlated respectively with clinical worsening or improvement. Coexisting consolidated pneumonia with sonographic air bronchograms was noted in one patient who did not survive. CONCLUSIONS: Clinicians with access to point-of-care ultrasonography may use these findings as an alternative to chest X-ray or CT scan. Lung ultrasound imaging may assist in the efficient allocation of intensive care for patients with respiratory failure from viral pulmonary infections, especially in resource scarce settings or situations such as future respiratory virus outbreaks or pandemics.

The validity of 9 physical tests for full-thickness rotator cuff tears after primary anterior shoulder dislocation in ED patients.

PURPOSE: This study was undertaken to validate the diagnostic values of 9 different physical tests in emergency department patients with primary anterior shoulder dislocation (PASD) to select the best screening test for full-thickness rotator cuff tear (FTRCT) after PASD. METHODS: A prospective analysis of 49 consecutive patients with x-ray-confirmed PASD was performed. All patients were followed at an average of 6.9 days (ranged from 4 to 10 days) in the emergency department. On the day of follow-up, 9 physical tests (namely, Jobe test, external rotation lag sign test, infraspinatus muscle strength test, dropping test, drop test, liftoff test, internal rotation lag sign test, belly-press test, and belly-off test) followed by shoulder ultrasound scan were performed to detect FTRCT. RESULTS: The prevalence of FTRCT after PASD is 37% (95% confidence interval [CI], 24%-52%). Fourteen percent of the patients with PASD were complicated with isolated supraspinatus tendon tear, whereas 22% were complicated with supraspinatus tendon tear combined with subscapularis and/or infraspinatus tendon tear. Jobe test has the highest sensitivity among the 9 physical tests being evaluated. The sensitivity, specificity, positive predictive value, negative predictive value, likelihood ratio for positive test, and likelihood ratio for negative test of Jobe test as a screening test for FTRCT after PASD are 89% (95% CI, 64%-98%), 55% (95% CI, 36%-72%), 53% (95% CI, 35%-71%), 89% (95% CI, 65%-98%), 1.97 (95% CI, 1.29-2.99), and 0.20 (95% CI, 0.05-0.79), respectively. CONCLUSIONS: The prevalence of FTRCT after PASD is 37% (95% CI, 24%-52%). Jobe test has the highest sensitivity (89% CI, 64%-98%) among the tests.

Dynamic ultrasonographic sign for posterior shoulder dislocation.

Acute posterior shoulder dislocation is rare, and its early diagnosis remains a challenge to the emergency physician. This report describes two cases of acute posterior shoulder dislocation confirmed by bedside ultrasound scan performed by the emergency physician. Bedside ultrasound for diagnosis of posterior shoulder dislocation is accurate, noninvasive, repeatable, convenient, and without ionizing radiation. Dynamic ultrasound sign of posterior shoulder dislocation and using bedside ultrasound for verification of successful reduction of posterior shoulder dislocation are described.