Browsing Tag

pulmonary

Ultrasound Pleural Effusion And Spine Sign

In this ultrasound still image, I have a phase array probe positioned on the left side of the body around the 8th rib. A left-sided pleural effusion is noted. It's important to appreciate this view to look for free fluid in the subphrenic…

Equal Pressure Point In Lung Physiology

Before reading this post, it's important to understand the basic physiology behind breathing. Normally, intrapleural pressure (Pip) isnegative, but during a forced expiration, the usage of expiratory muscles can drive the Pip upward. This,…

High Flow Nasal Cannula (HFNC)

High flow nasal cannula (HFNC) systems allow us to deliver warm, humidified oxygen at flow rates as high as 60 liters/min through small, pliable nasal prongs. The cannula itself is fit into the nares and stabilized with a head strap. Two…

What Is Pleurodesis?

Pleurodesis is a procedure aimed to obliterate the intrapleural space and is performed for recurrent malignant/non-malignant effusions and recurrent pneumothorax. 

Hypoxic Pulmonary Vasoconstriction (HPV)

Hypoxic pulmonary vasoconstriction (HPV) is an intrinsic property of the lung where vascular smooth muscle will constrict pulmonary circulation in response to areas of hypoxia. In other words, if an alveolus is not being well ventilated…

Lung Sliding On Ultrasound

During normal respirations, the parietal pleura slides over the visceral pleura. This movement can be visualized with ultrasound. The lack of sliding can be a concerning sign for pneumothorax, although data suggests that such a finding may…

PaCO2 Equation

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…

Alveolar Gas Equation

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.

Oxygen Delivery Equation

One of the most important equations in physiology describes the delivery of oxygen to tissues in the body. Naturally, this would be related to the cardiac output (CO) and overall oxygen content in the blood (CaO2). As I wrote about in a…