Jun 12 2017
Hypoxaemia and respiratory failure,
Are not one and the same.
to PaO2s below eight.
If above, then failure isn’t the name.
May 29 2017
The alveolar gas equation
Gives alveolar O2.
With this value in mind,
The Aa gradient you’ll find.
And gas exchange efficiency you can view.
Apr 3 2017
A PaO2 of 7 kIlo pascals,
Is enough to make you flinch.
As the idiots whine,
So we’ll call it 1 pound per square inch.
Mar 13 2017
If you ascend to high altitude
Altitude sickness can be atrocious
It may offer some consolation (or not)
To know it’s respiratory alkalosis
Feb 27 2017
A forced expiratory measure,
Requires full inhalation.
It makes the airways more patent,
And provides the best exhalation.
Feb 20 2017
Buffers are weak acids
The addition or loss of some proton
Is offset by changing this fulcrum
Feb 13 2017
The PaO2 represents,
Just a fraction of the O2 content.
Its importance you see,
Is what saturation would be,
As THAT accounts for some 98%.
Jan 2 2017
Unique to the pulmonary tree.
It can occur on ascent to altitude,
Or as a consequence of COPD.
14 Nov 2016
Distribution of beta-recetors:
One heart, two lungs and all that.
Just keep in mind, this is streamlined
But as good a place as any to start
26 Sep 2016
Is it underventilation?
V/Q mismatch, a block or a shunt?
If you’ve ruled out these,
That only leaves,
Environmental to cause this ailment.
28 Aug 2016
In a respiratory acid base problem
The bicarbonate alone won’t tell
If there’s any metabolic compensation
Since its depends on CO2 as well
15 Aug 2016
A case of pulmonary embolism
And a large reduction in flow.
Despite normal ventilation
Means VQ ratio is actually low.
7 Aug 2016
Is it better to ventilate,
Breathing half as much but at twice the rate?
Of course it’s not
Each breath loses air to deadspace
27 Jun 2016
It binds beta chains,
So its efficacy wanes,
In the fetus, where gamma’s more common.
5 Jun 2016
To maximise ventilation,
Breathe deep, at slow pace.
Rapid & shallow
Might produce the same air flow
But you’ll lose more to the dead space.
18 Apr 2016
Blood gases control ventilation
When they stray from the reference range
But this does not explain exercise
Where both are largely unchanged
4 Apr 2016
Training improves performance,
And reduces respiratory rate.
Don’t be confused,
Tissues are better perfused,
Reducing the amount of lactate.
14 Mar 2016
Blue with the cold I hear you say,
Want my diagnosis?
The reduced perfusion & increased extraction,
Has led to peripheral cyanosis.
7 Mar 2016
Flow through an artery or bronchi
Follows Ohm’s law, don’t you know.
Assuming a stable resistance,
A larger pressure gradient increases flow
29 Feb 2016
The PaO2 reference range,
Does not have an upper limit.
By 10.6 kPa, Hb’s saturated,
And availably is hardly infinite.
1 Feb 2016
The concept of hypoxic drive,
So often misunderstood.
If you think it kicking in,
Means CO2’s in the bin,
Then take a trip to high altitude.
18 Jan 2016
The pulmonary circulation,
Offers low resistance to flow.
It accommodates right cardiac output,
And keeps pulmonary pressures quite low.
28 Dec 2015
Hypoxia or ischaemia?
There’s a distinction you should know.
Both lead to low oxygen;
But ischaemia is only poor flow
23 Nov 2015
“It’s a cardioselective blocker;
Can be used in asthma” you boast.
A note of concern,
“Selective” is the term:
A property dependent on dose.
Aug 31 2015
Obstructive or restrictive?
That’s what you have to tell.
Obstructive has a low FEV1,
Restrictive, a low FVC as well.
Aug 17 2015
There’s evidence of hypoxaemia,
Is it V/Q mismatch or shunt?
Supplemental oxygen can distinguish,
Only mismatch will show improvement
Aug 9 2015
If the PaCO2 is low,
It doesn’t matter what the pH is.
There is clear hyperventilation,
That has produced a respiratory alkalosis.
May 4 2015
When perfusion exceeds ventilation
The extra blood flow is wasted
Can’t balance this equation
The blood’s already saturated
Mar 2 2015
That mischievous little bicarbonate,
It has two stories to tell.
It rises in metabolic alkalosis,
And in respiratory acidosis as well.
Feb 23 2015
The amount of gas that dissolves
On the partial pressure depends
Diving will dissolve more nitrogen
Coming up quickly gives you The Bends
Feb 16 2015
The dissolved oxygen content,
Is partial pressure dependent.
No matter what breathing you do,
Will never exceed the environment.
Feb 9 2015
Assessing blood gases at high altitude
There’s only one plausible answer
Hypoxaemia may well be present
But not due to respiratory failure
Jan 11 2015
The Henderson-Hasslebalch Eq.
Can induce a look of pain.
All it explains, is the ratio must stay the same
If the pH is to resist any change.
Nov 17 2014
Ascent to high altitudes
Results in hypoxic hyperventilation.
The upshot of this,
is respiratory alkalosis
& centrally driven CO2 retention.
Sep 15 2014
binds the beta chains of Hb.
Of course not the same, fetus has delta not beta chain,
so here it can’t effect affinity
Jul 20 2014
A saturation of 50%,
means that half your Hb are empty.
Wait, I implore!
It’s not 2 out of 4,
as each subsequent oxygen increases affinity.
Jul 1 2014
Oxygen is vital,
without it you’d be dead.
But this is not ventilation’s primary concern,
that is acid base balance instead.
Jun 22 2014
Most CO2 is carried as HCO3-.
A gas or by Hb what remains.
At first it may seem, it’s bound to the haem,
But in fact binds the globin chains
Jun 15 2014
The Henderson-Hasslebalch equation,
tells you all you need to know.
The pH can always be corrected,
by restoring the acid to base ratio.
30 May 2014
Raised CO2 is hypercapnia,
but it tells you more than this.
It is by definition hypoventilation
and respiratory acidosis.
6 Apr 2014
Three cheers for J.S. Haldane,
and the effect that bears his name.
A stronger acid, oxy-Hb
liberates protons and CO2 from the globin chain.
17 Mar 2014
The Bohr effect is beautiful;
The uptake of CO2 into the erythrocyte
enhances O2 delivery.
2 Mar 2014
Anaemia is a low haemoglobin,
and may make you hypoxic.
But there is rarely enough
of that carrying stuff
For you to also appear cyanotic.
3 Feb 2014
Haemoglobin is the workhorse
And its saturation is the key;
The PaO2 informs this
As they interact sigmoidally.
26 Jan 2014
The PaO2 is important,
but this only represents;
the dissolved O2 component
and so a fraction of oxygen content
19 Jan 2014
In acid base balance,
Acidosis requires compensation.
Metabolic acids stimulate carotid chemoreceptors
6 Jan 2014
As hydrogen binds to globin chains
It makes O2-haem binding less likely.
Since respiring tissues release H+,
so it increases oxygen delivery
30 Dec 2013
A high respiratory rate, or tachypnoea,
is just that in any situation.
But so you know,
the PaCO2 must be low
for it to be hyperventilation.
17 Oct 2013
When O2 binds to haemoglobin,
it’s called an OXYGENATION.
No loss of electrons occurs
so it can’t be an OXIDATION
16 Oct 2013
Hypoxia & cyanosis
You use these interchangeably
But they mean something distinct
So are spelt quite differently