I figure as an anesthesiologist and intensivist, I should have a post on the basic mechanism of breathing. Here’s my attempt to simplify this complex process while maintaining some of the important details! :-)
Heart muscle cells (cardiomyocytes) can undergo physiologic and pathologic remodeling when faced with differing hemodynamic loads and neurohormonal environments.
It’s always interesting to see how practitioners interpret the utility of lactate. Some find it completely useless, others think it’s a marker of poor oxygen delivery, and a decent number trend lactates as a way to measure the response to therapy. So let me briefly discuss my views on lactate during a…
The oxyhemoglobin dissociation curve (ODC) is one of the most recognized teachings of basic physiology. It describes the relationship between the saturation of hemoglobin and the partial pressure of arterial oxygen. Intuitively, it makes sense that the more oxygen available (a higher PO2), the more saturated hemoglobin will be (% saturation). But…
I’ve previously written about the alveolar gas equation and oxygen delivery equation, both of which deal with the physiologic process of oxygenation. Now I want to discuss the important relationship between alveolar ventilation (VA), carbon dioxide production (VCO2), and alveolar carbon dioxide tension (PACO2). For this explanation, PACO2 roughly approximates arterial…
I previously wrote about the oxygen delivery equation mathematically describing a vital concept in physiology. Now I want to discuss another critically important formula in acute care medicine – the alveolar gas equation.
The arterial oxygen delivery (DO2) equation is undeniably one of the most essential physiologic principles. DO2 is comprised of two variables: It’s crucial to consider acute changes (e.g., hemorrhage and desaturation) in the context of this equation. As shown, hemoglobin concentration and the oxygen saturation of that hemoglobin are the most…
Maintaining coronary perfusion pressure (CPP) is arguably the most important objective in cardiac anesthesiology. CPP is defined as the difference between aortic diastolic pressure (AoDP) and left ventricular end-diastolic pressure (LVEDP) when describing perfusion to the left ventricle. CPP = AoDP – LVEDP Coronary arteries originate from the aortic root,…