Table 1 Differential diagnosis for intraoperative tachycardia and hypertension

Underlying pathology

• Severe state of thyrotoxicosis caused by excess circulating thyroid hormones

• Inherited metabolic disorder initiated by halogenated volatile anesthetic agents or succinylcholine

• Precipitated by typical or atypical antipsychotics, antiemetics, or change in anti-parkinsonian drugs

• Rare neuroendocrine tumor of the adrenal medulla

• Secretes catecholamines

Presentation

• Hyperthermia^a

• Tachycardia^a

• Hypertension^a with widened pulse pressure

• Arrythmias

• Congestive heart failure

• Hyperthermia^a

• Tachycardia^a

• Hypertension^a

• Muscle rigidity

• Masseter spasm

• Increasing end-tidal CO₂

• Metabolic acidosis

• Myoglobinuria

• Hyperthermia^a

• Tachycardia^a

• Hypertension^a

• Altered mental status

• Extrapyramidal symptoms

• Muscle rigidity

• Rhabdomyolysis

• Hypertension^a

• Tachycardia^a

• Headaches

• Diaphoresis

• Intraoperative hypertensive crisis

Intraoperative diagnosis

• Thyroid panel with low to undetectable TSH and high free T4

• Clinical diagnosis during acute event based on patient presentation

• Can later do susceptibility testing

• Clinical diagnosis based on patient presentation and current medications

• Elevated creatine kinase

• Clinical suspicion based on hypertensive crisis and patient history

• Elevated plasma free metanephrines

• Post-op imaging

Immediate treatment plans

• Intraoperatively manage hemodynamics (beta blockers, cooling blankets, vasodilators)

• Discontinue halogenated agent

• Administer dantrolene

• Provide “clean” source of oxygen

• Discontinue causative agent (dopamine antagonists) and stop potential contributing agents

• Provide supportive care to maintain cardiopulmonary stability and euvolemia

• Initiate alpha adrenergic blockade (phentolamine or phenoxybenzamine)

• Treat hypertension and arrythmias

• Discontinue surgery if possible