Advanced practice note
Induction hypotension is a diagnosis, not simply a reading
A structured way to distinguish loss of vascular tone, impaired preload, reduced contractility, and obstruction in the minutes around induction.
The same arterial pressure can be produced by very different haemodynamic states. Around induction, the differential is often familiar but still easy to compress into a reflexive bolus or vasopressor: reduced sympathetic tone, unrecognised hypovolaemia, ventricular dysfunction, dynamic obstruction, increased intrathoracic pressure, or an evolving reaction to a drug.
Start with the time course. Did the pressure fall immediately after induction, after positive-pressure ventilation, after positioning, or after an antibiotic? Pair that sequence with pulse pressure, heart rate, airway pressure, capnography, peripheral perfusion, echocardiographic windows when available, and the operative context. The pattern is usually more informative than the absolute number.
The mature response is both therapeutic and diagnostic. Treat compromised perfusion promptly, then reassess whether the response fits the proposed mechanism. A vasopressor that restores pressure but leaves the broader physiology unexplained has answered only part of the question.