ST What?! Recognising Myocardial Ischaemic ECG Changes!

Acute Coronary Syndrome (ACS) does not refer to an adorable coronary artery too cute for it’s own good; it refers to a group of conditions that result in decreased coronary blood flow to the myocardial tissue. With a decreased coronary blood flow, there is a decreased supply of oxygen to the myocardial tissue. And nothing is as bad to the myocardial tissue than a lack of oxygen! If you are the superstitious type, you will believe that all bad things come in threes. No truer words have ever been spoken, with the 3 issues that result from a lack of oxygen to the myocardial tissue all starting with a capital “I”…
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Demystifying the 12 Lead ECG!

ecg dot application hair removal image

Whether you work within a coronary care unit or a general surgical unit, we have all performed a 12 lead electrocardiogram (ECG) on one of our patients at some point or another. We’ve prepped the chest of a patient that could rival some of the sheep shearing competitions that occur in New Zealand. We’ve tried untangling the mess of leads while secretly imagining the face of the colleague that left the ECG machine in such disarray on the dart board of our local bar. We’ve all had to deal with that ONE patient who cannot comprehend what it means to “lie still and quietly”. And after all of that effort to get that perfect print out of an ECG, wouldn’t it be nice to understand what those 12 leads are actually telling you?  Continue reading

Massive Blood Transfusions and Making the Blood Clot!

Blood Transfusion Negative

Ouch! I’ve just given myself a paper cut!

*Utters a string of expletives that would make a pirate blush*

As I apply pressure to my haemorrhaging war wound, I notice that the bleeding slows down to a stop. That is because my body is able to clot at the site of this small injury according to the physiology of the clotting cascade. However, it would be a different situation if I was in a horror movie and had my arm chewed off by zombies! I would now be experiencing a massive loss of blood that would result in the need for a massive blood transfusion. The internal processes of the body to clot may not be sufficient in the setting of a massive haemorrhage, and so it will need the help of some friends in the form of other blood products to help stop the bleeding.

*Cue the Rocky theme song as I battle through a horde of zombies with one arm to find an abandoned hospital, with a fully functional blood fridge, to initiate a massive blood transfusion protocol* Continue reading

The Clotting Cascade Made Easy!

At some point or another, there is a strong probability that we have all seen that dreaded flow chart. You know, the one with all the roman numerals that looks like it was created with the sole intent of confusing us. The one that we try to memorise but secretly hope that no one ever asks us about it. Do you know the one I’m talking about? That’s right; the dreaded coagulation or clotting cascade! And this article is going to simplify it to a point that you not only get it, but remember it as well! Continue reading

Oxygen Flow Rate and FiO2: Understand the Relationship!

Oxygen, we all need it! We do not need a lot of it under normal circumstances, with 0.21 being the fraction of inspired oxygen (FiO2) of room air. FiO2 is defined as the concentration of oxygen that a person inhales.  The air that we inhale on a day to day basis is made up of 21% of oxygen, 78% of nitrogen and 1% of trace elements such as argon, carbon dioxide, neon, helium and methane. For the purposes of this article, fractions and percentages will be used interchangeably for ease of explanation.  Continue reading

Head Injury: When the First Cut is NOT the Deepest!

If Grey’s Anatomy has taught us anything, it is to assess for secondary brain injury following ANY head injury! Things could have gone so differently for our favourite McDreamy neurosurgeon…

It is important to acknowledge that however bad a primary brain injury might be, it is the secondary brain injury that kills the person. Continue reading

Sickly Sweet: Understanding Diabetic Ketoacidosis

Diabetic ketoacidosis (DKA) is a potentially life threatening condition that can occur to people with diabetes. It is observed primarily in people with type 1 diabetes (insulin dependent), but it can occur in type 2 diabetes (non-insulin dependent) under certain circumstances. The reason for why it is not often seen in people with type 2 diabetes is because their body is still able to produce insulin, so the pathophysiology explained in the flowchart below is not as dramatic as compared to people with type 1 diabetes who do not make any insulin at all. Continue reading

The No Kiss Zone: Hands Only CPR Saves More Lives

compression only cpr statistics

Most people who experience a cardiac arrest in the community die because they do not receive immediate cardiopulmonary resuscitation (CPR) from someone on the scene. As a bystander, do not be afraid to do something. Your actions can only help. If you are in the healthcare field, please advocate the importance of this to all the people in your life! After all, they may be the ones having to do CPR on you one day! Continue reading

Diagnose ANY Arterial Blood Gas in 5 Easy Steps: Get it Right, Every Single Time!

It is important to understand that the pH in our bodies likes to stay within the very narrow range of 7.35 – 7.45. In the physiologically functioning body, this is achieved by the respiratory system maintaining a carbon dioxide (CO2) level between 35 – 45 mmHg and the metabolic system maintaining a bicarbonate level between 22 – 26 mEq/L.

When a pathophysiological process causes the CO2 or bicarbonate levels in our body to move outside of their normal ranges, the pH is affected and also moves outside of it’s normal range. Continue reading

Respiratory Failure: Type 1 or Type 2?

To recap the last blog post about oxygen saturations versus PaO2:

  • Respiration is the process of gas exchange, both at the alveoli to blood interface and blood to cellular tissue interface
  • Oxygen has to bind to haemoglobin in order to be effectively transported around the body, but must dissociate from the haemoglobin prior to be taken up by the cells
  • The amount of haemoglobin in the body that has oxygen attached is measured via oxygen saturations while the amount of oxygen freely floating in the blood unattached to haemoglobin is measured via PaO2
  • When we experience a failure to oxygenate, we have a problem with our oxygen
  • A decrease in oxygen saturations below 90% will cause the body to increase it’s ventilatory effort as a compensatory mechanism
  • A failure to oxygenate is known as type 1 respiratory failure, defined as a decreased PaO2 with a normal carbon dioxide level

In this blog post, we are going to discuss type 1 and type 2 respiratory failure in detail and explore which pathophysiological respiratory conditions lead to which type of failure. Continue reading