80 year old

Blood gas shows:

PH  7.17  Acidosis    (Moderate)

PCO2  83         Respiratory acidosis

HCO3   29    (elevated)

Lac 0.9  (Normal)

Na 133

Creat 50 (Normal)

Compensated HCO  ~ 26

( 1 for 10 in acute, 4 for 10 in chronic)

BE  -2.2  (acidosis)

Hb 159   High Hb – COPD, dehydration

Glu 13   High Glucose – poorly controlled diabetes, stress response, steroids

PAO2: (Fio2 x 713) – (PCO2 x 1.25)   = (313.72)  – (103.75) = 209

A-a Gradient   = PAO2 – PaO2  =   209 – 64 = 146

Normal A-a Gradient =  < Age/4  + 4  = 24

Alternate formula :  A-a Gradient (at sea level) A-a Gradient = FIO2 x (760 – 47) – (1.2 * PCO2) – PO2.  =  FIO2 at 6 L oxygen  = 0.44.

= 146

A-a Gradient: 146   ( Elevated; Large)

Significantly large A-a gradient which suggests VQ mismatch, shunt or diffusion defect

Type II Respiratory failure

 

 

Conclusion:  Severe acute compensated respiratory acidosis 

Causes:     (Obstructive Pul Disease – increase dead space)

Infective

non-infective

Pneumothorax

CCF

 

Management:

Resuscitate  Oxy/NIV

reduce Oxygen to prevent worsening CO2, consider urgent NIV

Treat underlying cause  Abx/Steriods

ICU/HDU level care after establishing boundaries of care