Pitfalls in anticoagulant-related nephropathy.

Anticoagulant-related nephropathy (ARN) is a rare but important disease and often misdiagnosed. The hallmark of the diagnosis is acute kidney injury (AKI) superimposed on preexisting kidney disease due to anticoagulation-induced glomerular hemorrhage with histologic features of widespread tubular obstruction by red blood cells and red cell casts. As ARN is a diagnosis of exclusion only proven by renal biopsy, the diagnosis is often unlikely to be confirmed histologically because of fear of biopsy-related bleeding during anticoagulant therapy. Given the large differential diagnosis in AKI, diagnosing ARN remains a challenge for clinicians. A case report and the pitfalls related to diagnosis and management will be discussed in this paper.

Altitude Pre-Acclimatization with an Erythropoiesis-Stimulating Agent.

Introduction: High altitude illness is a complication of rapid ascent above 2,500 m elevation. Ventilatory, circulatory and haematological adjustments, known as acclimatization, occur to maintain adequate delivery of oxygen. Although (non-)pharmaceutical strategies that modulate ventilation and circulation have long been accepted, the haematological approach has not. Case description: This report describes the application of a comprehensive strategy, including prior pre-acclimatization using an erythropoiesis-stimulating agent (ESA), in two healthy subjects ascending from sea level to 6,268 m. Following ESA administration 30 days prior to ascent, the subjects had a cumulative haemoglobin rise of 7.1% and 11.9%, respectively. Both subjects experienced minimal symptoms during four incremental ascents to the final altitude and no adverse events occurred. Discussion: This report has limited external validity, lacking both a sample size and controls, but can serve as practical exploration of the concept. Administration of an ESA may be a safe and useful pre-acclimatization strategy but cannot be recommended based on current evidence. More comprehensive research is needed. LEARNING POINTS: High altitude illness (HAI) is a debilitating syndrome with potentially lethal consequences caused by ascent to a hypobaric atmosphere without acclimatization.Pharmacological strategies aimed at increasing oxygen delivery may be used to prevent and treat HAI.Administration of an erythropoiesis-stimulating agent may be a safe and useful pre-acclimatization strategy but cannot be recommended based on current evidence alone.

Bacterial Contamination of Ultrasound and Stethoscope Surfaces in Low- and High-Resource Settings.

Point-of-care ultrasound is an accurate diagnostic and monitoring tool. Its increasing affordability, portability, and versatility make it an excellent component of standard clinical evaluation alongside the stethoscope. However, like the stethoscope, ultrasound carries risks of surface contamination and potential cross-infection. In this international observational study, we compared the surface contamination of ultrasound equipment to stethoscopes in two medical centers: a tropical low-resource hospital and academic high-resource hospital. Ultrasound equipment and coupling gel had similar prevalence of microbial surface contamination compared with observed stethoscopes. Most microbes were commensal Gram-positive, but some were opportunistic and pathogenic microbes (such as Escherichia coli and Staphylococcus aureus). In conclusion, it is crucial to appreciate and reduce the risk of ultrasound device contaminations. When ultrasound is used bedside, similar to stethoscopes, conscientious hygiene measures are equally fundamental.

Hyperosmolar Therapy for Diabetic Hyperosmolar Ketoacidosis.

Hyperglycaemic hyperosmolar state (HHS) and diabetic ketoacidosis (DKA) features can occur simultaneously in 27% of diabetic emergencies and have a two-fold increased risk of death. Despite the high prevalence of this combination, recommended treatments from leading guidelines may not be compatible with the clinical picture. A 36-year-old man presented with explicit concurrent HHS and DKA. The recommended treatment with simultaneous insulin and volume repletion was followed but resulted in an excessively rapid decline in serum osmolarity. Hyperosmolar therapy (NaCl 3%) was initiated to mitigate the risk of potentially fatal cerebral osmotic shifts. The concomitant presence of DKA and HHS leads to a treatment dilemma with a high risk of excessive osmolarity shifts. More evidence is needed, but it is reasonable to initiate tailored treatment to avoid osmolarity reduction rates exceeding the hypernatraemia-based limit of 24 mOsm/l/day. Hyperosmolar therapy can be considered but requires frequent monitoring of electrolytes and osmolarity. LEARNING POINTS: Simultaneous hyperglycaemic hyperosmolar state (HHS) and diabetic ketoacidosis (DKA) features occur in 27% of diabetic emergencies and have an almost three-fold increased risk of death.Combined HHS and DKA requires simultaneous insulin and volume repletion, which may result in an excessive decline in serum osmolarity. More evidence is needed, but it is reasonable to avoid osmolarity reduction rates above the hypernatraemia-based limit of 24 mOsm/l/day.Consider hyperosmolar therapy (NaCl 3%) to mitigate the risk of potentially fatal cerebral osmotic shifts.

Intoxication by Hand-Sanitizers and other Toxic Alcohols in a Low-Resource Setting: Two Case Reports.

Toxic alcohol poisoning can be lethal if not identified early and treated appropriately. Toxic alcohol assays are often unavailable in low-resource setting, so clinicians have to infer a diagnosis based on suspicion, repeated evaluation and biochemical course. We report a case of toxic alcohol poisoning concealed by auto-intoxication with in-hospital hand sanitizer. The eventual appearance of a concurrent high anion gap prompted dialysis. In another case, a comatose patient presented with a high osmolal gap and a high anion gap. Incorrect a priori opinions caused us to defer dialysis and the patient died shortly afterwards. Clinicians should be aware that toxic alcohol poisoning can produce a confusing diagnostic picture with an insidious course, and that doctor delay can prove fatal. LEARNING POINTS: Toxic alcohol ingestion may be lethal and warrants early identification, but this is not always possible.Incorrect a priori opinions by clinicians, or the co-ingestion of other alcohols by a patient, may produce a confusing diagnostic picture.Physicians should not defer immediate treatment for patients suspected of toxic alcohol ingestion with a double gap or visual disturbances.

Review of the Diagnostic Evaluation of Normal Anion Gap Metabolic Acidosis.

BACKGROUND: Normal anion gap metabolic acidosis is a common but often misdiagnosed clinical condition associated with diarrhea and renal tubular acidosis (RTA). Early identification of RTA remains challenging for inexperienced physicians, and diagnosis and treatment are often delayed. SUMMARY: The presence of RTA should be considered in any patient with a high chloride level when the CL-/Na+ ratio is above 0.79, if the patient does not have diarrhea. In patients with significant hyperkalemia one should evaluate for RTA type 4, especially in diabetic patients, with a relatively conserved renal function. A still growing list of medications can produce RTA. KEY MESSAGES: This review highlights practical aspects concerning normal anion gap metabolic acidosis.

Acid-base pathophysiology after 130 years: confusing, irrational and controversial.

BACKGROUND: The interface between acid-base physiology and blood gas interpretation is historically both stimulating and turbulent. Since the pioneering work of many celebrated names in the history of acid-base disorders, such as Arrhenius, Henderson, Hasselbalch and many more to follow, substantial progress in acid-base knowledge has been made over the last 130 years. Out of the chaos of competing definitions, concepts and terms, many have tried to bring an orderly approach to acid-base balance. Nevertheless, the mechanisms responsible for acid-base balance are unfortunately still incompletely understood, and moreover, considerable controversy has developed over the past decade as to how to classify and understand acid-base derangements occurring as a result of abnormalities in acid-base balance. METHODS: Analysis of the medical literature, including a MEDLINE and EMBASE search, and a search of internal medicine, critical care and nephrology textbooks and reference lists, was performed on topics pertaining to the assessment and management of acid-base disorders, focusing on the gaps in our knowledge and on controversial issues. RESULTS: Several confusing, irrational and controversial issues concerning acid-base nomenclature, reference values, pathophysiology, assessment of acid-base disorders and therapy were found. CONCLUSIONS: Despite huge progress in acid-base knowledge, several confusing, irrational and controversial issues remain. Suggestions to reduce the confusion are provided.

Chloride: the queen of electrolytes?

BACKGROUND: Channelopathies, defined as diseases that are caused by mutations in genes encoding ion channels, are associated with a wide variety of symptoms and have been documented extensively over the past decade. In contrast, despite the important role of chloride in serum, textbooks in general do not allocate chapters exclusively on hypochloremia or hyperchloremia and information on chloride other than channelopathies is scattered in the literature. STUDY DESIGN: To systematically review the function of chloride in man, data for this review include searches of MEDLINE, PubMed, and references from relevant articles including the search terms "chloride," "HCl," "chloride channel" "acid-base," "acidosis," "alkalosis," "anion gap" "strong anion gap" "Stewart," "base excess" and "lactate." In addition, internal medicine, critical care, nephrology and gastroenterology textbooks were evaluated on topics pertaining the assessment and management of acid-base disorders, including reference lists from journals or textbooks. CONCLUSION: Chloride is, after sodium, the most abundant electrolyte in serum, with a key role in the regulation of body fluids, electrolyte balance, the preservation of electrical neutrality, acid-base status and it is an essential component for the assessment of many pathological conditions. When assessing serum electrolytes, abnormal chloride levels alone usually signify a more serious underlying metabolic disorder, such as metabolic acidosis or alkalosis. Chloride is an important component of diagnostic tests in a wide array of clinical situations. In these cases, chloride can be tested in sweat, serum, urine and feces. Abnormalities in chloride channel expression and function in many organs can cause a range of disorders.