Respiratory Acidosis

Respiratory Acidosis Pathophysiology

When the excretion of CO2 via the lungs fails to keep up with the body's production of CO2 respiratory acidosis will occur. So basically we got a lot of CO2 up in here and it won't leave, its drunk and needs to call an uber home.

What the powerpoint said the symptoms were

anxiety, irritability, increased pulse, flushed skin....

What causes Respiratory Acidosis

Conditions or circumstances that impair the lungs ability to excrete CO2. People who are HYPOVENTILATING. Two main things to remember "Won't Breathe" and "Can't Breathe" "Won't Breathe" - A decrease in respiratory drive "Can't Breathe" - decrease in respiratory muscle or chest wall function. Obviously there's more to it than that we could go deep into CNS disorders (Acute/chronic hypoventilation), obesity hypoventilation syndrome, pneumothorax, chest wall trauma, REM sleep, emphysema, COPD, exercise, fever, thyrotoxicosis, multiple-organ failure, etc... I'm not going into it so "won't breathe, can't breathe" will do for now. Oops I almost forgot. Opiate overdose causes respiratory depression give them Nalaxone (Narcan),

Other symptoms

Hypercapnia (lots of CO2) releases catecholamines (epinephrine and norepinephrine) which usually cause vasoconstriction, BUT because CO2 is a strong independent woman who don't need no man, it has an inhibitory effect on vascular smooth muscle, which causes vasodilation and leads to increased heart rate and possibly elevated blood pressure. Because of the peripheral vasodilation cause the patients skin will also feel warm and flushed.

Supplemental oxygen

Most patients with hypercapnia are also hypoxemic and supplemental oxygen helps decrease mortality. Well isn't that just dandy. EXCEPT IT'S JUST AS DANGEROUS AS VENTILATION in patients with chronic respiratory acidosis. Yeah, apparently these individuals with a chronic increased PaCO2 (COPD patients) have a blunted hypercarbic drive and their main stimulus to breathe is their Hypoxic drive. So, if we take their oxygen level (PaO2) above the stimulus point of their hypoxic drive, they could begin to have worsening respiratory depression LEADING TO WORSENING RESPIRATORY ACIDOSIS! Just relax on the O2 and keep the level in the low 90% range

CNS symptoms... I lied.

Okay, CO2 can rapidly cross the blood-brain barrier and lower the Ph of Cerebrospinal fluid (CSF), causing cerebral vessel dilation, increased cerebral blood flow, and increased intracranial pressure. BASICALLY our body really doesn't like that SOoo, manifestations of that are Anxiety, irritability, headache, confusion, disorientation, and lethargy.

Intubation for respiratory acidosis

The mother of all invasive techniques in this situation is gonna be endotracheal intubation and the use of mechanical intubation. General rule is PaCO2 in the 80-90 range and Ph of 7.10-7.25, but it all comes down to what the doctor thinks. Oh and to make matters worse if we intubate and correct the PaCO2 too quickly it can CAUSE METABOLIC ALKALOSIS AND ALKALINIZE THE CSF, CAUSING SEIZURES. Yup.

so how are we gonna fix it?

Treat the underlying disorder! Drug overdose may need Naloxone, inhaled bronchodilators and steroids to treat acute asthma attacks, antibiotics to treat pneumonia. Improve the ventilation = correcting the acidosis. Bicarbonate is almost NEVER given, "well why not?" you may be asking. BECAUSE! BICARB eventually turns into CO2 in the body making everything worse! Only in a cardiac arrest situation with a Ph of like less than 7.0 and there's metabolic acidosis and respiratory acidosis blah blah blah its really bad they need perfusion to the heart in order to even possibly survive.