14 Emergency Medicine
“Before running the code, check your own pulse” – Dr Paul L. Bernstein, Rochester, NY 14.1 Basic Life Support When a person is found unresponsive: aIn patients found unresponsive with…
Models for point-of-care testing of critical care analytes
Introduction Point-of-care testing (POCT) is now common in many near-patient and critical care settings. For blood gas and electrolyte testing, this includes operating rooms (ORs), intensive care units (ICUs), cardiac…
Collection and handling of samples: effects on blood gases, Na, K, ionized Ca, Mg, lactate, and phosphate analyses
Sources of preanalytical errors in blood gas and electrolyte testing Introduction There are numerous sources of preanalytical errors in laboratory testing. Among these are the following: • Wrong test ordered…
Quality control in blood gas and critical care testing
Routine daily quality control on blood gas instruments Most current blood gas/electrolyte/metabolite analyzers have onboard internal quality control (QC) systems that automatically monitor the stability and performance of reagents, electrodes,…
Lactate physiology and diagnostic evaluation
Introduction By 1900, many physicians had noted metabolic acidosis in patients who were critically ill. In 1925, Clausen identified increased lactate along with acidosis in these patients, which gave rise…
Osmolality, sodium, potassium, chloride, and bicarbonate
Osmolality and volume regulation Introduction Osmolality in plasma is related to the number of solutes (soluble particles) dissolved in a kg of plasma water, with a normal osmolality between 280…
Phosphate physiology and clinical evaluation
Introduction Symptoms of phosphate depletion have been described through the years, from the times of the ancient Romans to observations by veterinarians on livestock. Phosphate compounds are in all cells…
Magnesium physiology and clinical evaluation
Introduction In 1695, from well water in Epsom, England, Dr. Nehemiah Grew prepared Epsom salts, a name still given to magnesium sulfate. The biological significance of magnesium as a constituent…
Calcium physiology and clinical evaluation
Introduction and history In 1883, Sydney Ringer showed that calcium was essential for myocardial contraction ( ) . In 1934, Franklin McLean and Baird Hastings published a report in the…
Disorders of oxygenation: hypoxemia and tissue hypoxia
Introduction Hypoxemia, a decreased partial pressure of oxygen in the blood, is a commonly encountered clinical problem among patients with acute or chronic cardiopulmonary disorders. Accurately characterizing the cause and…
