Lab Case 318 Interpretation

A 48 year old female presents to ED with a 3 day history of abdominal pain, vomiting and inability to eat. The patient has a background of a previous gastric sleeve. Patients VBG below:

pH 7.130                                 Na 144 mmol/l

pCO2 34 mmHg                      K 4.2 mmol/l

HCO3 10 mmol/l                     Cl 108 mmol/l

BSL 3.5                                    Cr 63 umol/l

Lactate 2.0                               Ketones 7.1 mmol/l

  1. Describe and interpret the VBG
  2. What complications can occur post gastric sleeve surgery?

 

Metabolic acidosis pH 7.120 HCO3 10 mmol/l

Compensation – Expected PCO2 = 1.5 X HCO3 + 8 = 23 mmHg

AG = Na – (HOC3 + Cl) = 26

Delta Ratio = Change in AG/Change in HCO3 = 1

Corrected potassium – +/- 2.7mmol/l

BSL 3.5 and Ketones 7.1

The above VBG shows an uncompensated high anion gap metabolic acidosis, with an underlying respiratory acidosis. The patients BSL is borderline low. The patients corrected potassium will be low in the context of the low pH. The HAGMA is most likely due to a keto acidosis. There is no history of diabetes, but euglycaemic ketoacidosis secondary to SGLT2 inhibitors needs to be excluded. There is no history of alcohol ingestion, therefore the cause of the ketosis is likely a starvation ketosis from patients inability to eat. The high ketones will exacerbate the patients vomiting.  The underlying respiratory acidosis could be due to respiratory splinting if the patient is peritonitic.

Complications related to gastric sleeves include bleeding from gastric vessels, gastric outlet obstruction, gastric leaks, reflux.