The water tablet's chemistry

core

An 81-year-old on escalating furosemide doses for leg swelling, admitted with weakness and cramps. She is thirsty and her mouth is dry.

Blood gas

pH7.50

PaCO249 mmHg

HCO337 mmol/L

Na134 mmol/L

Cl88 mmol/L

K3 mmol/L

No high/low cues on purpose: read the numbers the way the gas machine prints them.

Stepwise interpretation

Commit to your own read first: pH, primary process, compensation, gap, delta, oxygenation. Then walk the engine’s steps and see where you agree.