Hypoxemia: Oxygen Therapy and Ventilation/Perfusion (VQ) Mismatches

Hypoxemia is an abnormally low concentration of oxygen in the blood which can lead to dire consequences when left unmanaged. In most patients with hypoxemia, the application of supplemental oxygen is a quick bandaid therapy that is often applied to counteract the problem. However, have you ever applied supplemental oxygen to a patient experiencing hypoxemia and there has been a minimal effect? Have you ever wondered why the application of supplemental oxygen works in some patients but not others? It all comes down to what is causing the hypoxemia and understanding the pathophysiology behind a ventilation/perfusion (VQ) mismatch.

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The Different Types of White Blood Cells

White blood cells (WBCs) circulate in the blood to help protect the body against infections, but also have a role in inflammation and allergic responses. There are various types of white blood cells and each of them can give us a lot of information around whether the infection or inflammatory response is bacterial, viral, auto-immune, allergic, acute or chronic. Continue reading

How To Analyse an ECG Systematically

ECG rhythm analysis

What is it about ECGs that make us take one quick glance at it and want to hide it in the patient’s folder where it belongs? ECG interpretation does take practice and can sometimes be tricky, but being able to identify an ECG that is not normal doesn’t have to be tricky at all! All you need is a process that is followed each and every time in order to analyse an ECG systematically! Continue reading

Cardiac Axis Deviation

right way wrong way sign

At some point or another, we have all heard someone mumble the terms “ECG axis”, “cardiac axis” or “cardiac axis deviation” when looking at a 12 lead ECG. But what does axis mean? I’ll let you in on a little secret, but you have to promise to tell EVERYONE! Here goes: cardiac axis is just a fancy way to discuss the flow of electrical conduction within the heart. And the kicker? It’s actually a relatively easy concept to understand.  Continue reading

How to Diagnose ANY Cardiac Rhythm Systematically

ecg heart flatline

Narrow complex tachycardia…hmm, but isn’t that supraventricular tachycardia?

Broad complex tachycardia…VT…no wait, it’s VF…hang on, asystole (oh, oh!)

It’s atrial fibrillation…wait, what about atrial flutter?

Regular, no wait…is that irregular?

Let’s not forget all those different heart blocks…

What happened to a good ol’ run of straight forward sinus rhythm?

With so many cardiac rhythms to remember, wouldn’t it be nice to be able to get to the correct diagnosis each and every time? The beauty about cardiac rhythms are that they are all fairly predictable. If you ask the right questions in a systematic manner, it will get you to diagnosing the right cardiac rhythm pretty much every time! Don’t believe me? Why not give it a shot by using this flowchart I have designed to do just that:

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Understanding How Anticoagulants Work

warfarin anticoagulation stop the clot

As discussed in the article “The Clotting Cascade Made Easy”, a blood clot is formed when activated platelets are trapped in stabilised cross linked fibrin. The process of fibrin formation is controlled by procoagulation factors (factors that promote blood clotting) and anticoagulation factors (factors that inhibit blood clotting). If the ability of the body to maintain this equilibrium is disrupted, we could either bleed to death or become one big blood clot! Continue reading

The Hypoxic Drive Theory…DEBUNKED!

breathing hypoxic drive

We’ve all heard it at some point or another: “Don’t give that COPD patient too much oxygen”. It has led us to believe that oxygen is a REALLY bad thing in patients with chronic obstructive pulmonary disease (COPD). This has caused nurses to be afraid to put oxygen on a COPD patient with low oxygen saturations (SpO2); yes, even in patients with SEVERE hypoxia! Why? Because of a little something known as the hypoxic drive… Continue reading

Removing the Road Blocks: Understanding Heart Blocks

cardiac conduction pathway

Ever wondered about the differences between a first, second and third degree atrioventricular (AV) heart block? And not to mention that second degree AV blocks can be further differentiated into type 1 or type 2? You know, because it wasn’t confusing enough as it was! This article is going to explain it all to you! But before we start making heart blocks something that is easy to understand, we should start with a bit of normal electrophysiology through the heart. After all, we can’t understand what is abnormal until we truly understand what is normal! Continue reading

CVVHDF What?! Renal Replacement Therapy Simplified…

acute kidney injury aki

Acute renal failure (ARF) is a new onset of the partial or complete reduction of normal kidney function which is characterised by the inability to remove excess water and metabolic wastes from the body. Continuous Renal Replacement Therapy (CRRT) is often indicated in ARF as well as some other conditions, with the decision to commence CRRT on a patient based on the following:  Continue reading

Chest X-Ray Interpretation in 7 Easy Steps!

chest xray analysis

It is important to understand that when a chest x-ray is taken, light is absorbed according to the density of what it passes. We have different densities within our bodies ranging from bone, to tissue, to fluid, to air. This results in a monochrome display ranging between white to black. There are three distinct things you should look for on a chest x-ray and they all rhyme: Continue reading