Arterial Blood Gases

We as respiratory therapists are experts in arterial blood gas procurement and interpretation. This places a burden on students of the profession as their preceptors and instructors expect a high level of understanding and performance with regards to arterial blood gases (ABGs).

An approach that may get a novice started is to work on the initial classification system. To help with this there are many tools but the tradition of using HCO3, bicarbonate, as a basis of interpretation is often problematic in my opinion. An alternative is to focus on the base excess (BE) to guide the classification. Here is a link to my website where these free tools are offered, check out the "Resources for  Clinicians" (http://respiratory-education.usefedora.com/). I have also created a Google Play application that also guides you through the classification and also provides some insight into the pathology or patient conditions that would be potentially consistent with an ABG classification.

This leads me to the next level of ABG interpretation. A practitioner should be aware of how the ABG results aid to the understanding of the patient's condition and treatment plan. Clearly this takes time to develop this level of understanding and students will gain experience by studying cases, a patient's history and clinical situations.

So as a student where does this leave us? Well using the tools and becoming an expert in the mechanics of classification and relating that to pathologies is a good start. My suggestion would be then to work on the application of this knowledge and using one of the most fundamental rules that I believe should always be applied.

Never interpret an ABG without knowledge of the patient's condition and history at the time of the ABG.

I can highlight the critical nature of this with a simple example, a patient has an ABG with a PaO2 of 85, SO2 of 98%, PaCO2 of 40, pH of 7.40, HCO3 of 24, BE of 0. Often when presented with these ABG values a student will suggest the patient has no immediate problems, then when confronted with the facts that the patient is on a non-rebreathing mask and a respiratory rate of 28 b/min the view of the ABG changes.

Another aspect of an ABG that is often overlooked is an assessment of oxygenation. Examination of the PaO2 and SO2 is only part of the equation, oxygen delivery is the other critical component so hemoglobin and cardiac output are critical and leads to my next rule of ABG assessment.

Never interpret an ABG or the oxygenation status of a patient without knowledge of the hemoglobin and cardiac status of the patient.

With these two simple rules in mind and in practice a novice practitioner of the respiratory arts is well on their way to being an expert. An important aspect of the application of these rules is to always ask for the patient information and provide the critical information when discussing ABGs.

Introduction to Mechanical Ventilation

I have been an instructor of respiratory therapy for many years and the topic of mechanical ventilation is an absolute passion of mine for it is the one area of medicine where we as respiratory therapists should be the absolute experts. This fuels my passion and frustration.

My fortune is that I'm gifted with teaching the course RESP 266 Interventions 1 which includes the introduction of mechanical ventilation along with many other course elements. Thus my first concern is that we have diluted the topic and time we as students spend on the subject. A challenge and an obstacle. In years of teaching I've never heard of a instructor who would not proclaim that the time allotted to his subject is insufficient to do it justice. My goal is to see that justice is done! Regardless of the time.

Okay so what advice would I give to students embarking on this introduction? The answer is to play. Play with the ventilators and the tools supplied for the simple pleasure of discovery. Spend the time to discover the ventilator control interactions in both the lab and at home on your computers. The tools are there, ventilator calculators, examples of control interactions, lab time with ventilators and case studies. Play with all of these with enthusiasm and vigor and you will be rewarded with understanding and insight.

In my view lecture time is wasted time. Hearing about it is one thing experiencing it is the real thing.

My zeal for this topic has driven me to create some learning tools that I hope students will find useful. Years ago it was Virtual Ventilators, now I have distilled the essence of that experience and my teaching to offer videos and a synthesis of control interactions on my website; http://respiratory-education.usefedora.com/. I have to charge for the course "Control Interactions" to recover some of my expenses in development but I believe it is a valuable resource for students.

I guess we will see.

Opinions of Common Humans

Does the common human have anything relevant to say?

In a world where we are constantly exposed to instant information, though I suspect often erroneous or misleading, can the average person have anything but an ill informed opinion? I ask this because I suspect that most of us do not have the time or ability to collate the facts.

Maybe some of us can be knowledgeable about a few areas within our expertise of work or special interests but really how are we to have viable opinions on things like gun control or pipeline construction? Who and where do we turn to for reliable information?

As a common human I feel I can only ask these questions and be skeptical of all the proclaimed experts. My personal experience of financial and political experts is that their analysis is only correct after the facts. How many times have I heard on CBC Radio the financial expert explaining to me that I was paying over $1 / L for gas because of high demand and low supply? Then the next week the price of oil goes down and the price at the pump goes up.

As beacons of hope I take solace in the writings of authors like Malcolm Gladwell and Carl Sagan who seem to grasp the need to focus their genius and give us a glimmer of insight. My problem is I'm not sure how their works alter the course of the world or if anyone of influence is even listening.

Another situation that troubles me is that I seem to be surrounded by individuals who tout that they are entitled to their opinions and that their opinions are as valid as anyone's. Even if it's their believe in an obscure god or that global warming is a myth. No longer does it seem that there needs to be any supporting facts or critical analysis. It now seems like it's enough to just have the opinion? It is often touted, in my little world, that everyone's opinion deserves as much attention and respect as others. Thus the dilemma we face when zealots indignantly demand equal education on creation as evolution because they are both equally valid opinions.

Now I have just as many ill informed opinions as anyone but I would like to believe that I'm not so foolish as to believe I'm correct. The problem in my view is how is an average human suppose to vote or give input into majorly important issues? How can we build trust in our news and other media sources to give us the information we need? Who can we trust? Is it time for us to give up on the notion that the common human is entitled to contribute to the decision making process of important issues like global warming or the economy? Are politicians even capable of making these decisions?

I doubt that they are, but that's only my opinion.