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Deliberate (Controlled) Hypotension
TEXTGeneral Principles VIII · 7 min read
Reducing MAP to a defined target to minimize surgical bleeding. Indications are narrow, the safety floor is firm, and the failure mode (stroke, MI, POVL) is catastrophic.
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2 min read5 sectionsIndications + mechanism
Deliberate hypotension is the intentional reduction of mean arterial pressure (MAP) to a defined sub-physiologic target to reduce surgical bleeding and improve operative field visualization.
- endoscopic sinus surgery (FESS)
- middle-ear/tympanoplasty
- orthognathic surgery
- hip arthroplasty (cemented stem, declining indication)
- spine fusion (declining — POVL risk)
- tumor resection (vascular acoustic neuroma, AVM, aneurysm clip placement during temporary occlusion)
- Jehovah's Witness procedures
Surgeon satisfaction and operative-field grading are the typical endpoints.
Target MAP + safety floor
50–65 mmHg in young healthy adultsNEVER reduce MAP below the patient's documented cerebral autoregulation floor (chronically hypertensive patients have a right-shifted curve — MAP 60 may already be hypoperfusion).
Maximum duration ideally <2 hours per the APSF position; longer durations escalate ischemic risk.
Stop deliberate hypotension immediately at surgical hemostasis — there is no benefit to maintaining a sub-physiologic MAP after the bleeding step is complete.
Pharmacologic toolkit
0.1–0.3 mcg/kg/min — opioid-mediated hemodynamic blunting, terminates rapidly.25–100 mcg/kg/min or labetalol bolus; reduce both HR and contractility, dampen reflex tachycardia.1–15 mg/hr or CLEVIDIPINE 1–32 mg/hr — selective arterial vasodilation, minimal reflex tachycardia, rapid offset.0.2–0.7 mcg/kg/hr — central sympatholysis, useful in FESS.Patient selection + contraindications
ABSOLUTE/STRONG contraindications: severe coronary artery disease, severe cerebrovascular disease (carotid stenosis), end-organ ischemia (renal, hepatic), pregnancy, sickle-cell disease, severe anemia, glaucoma, prone spine surgery (POVL risk — APSF specifically advises against deliberate hypotension in prone spine).
- chronic hypertension (right-shifted autoregulation)
- advanced age
- diabetes with microvascular disease
- prior stroke
Beach-chair shoulder surgery — DO NOT apply deliberate hypotension; multiple sentinel events of stroke and blindness linked to permissive hypotension in BCP.
Monitoring + complications
Consider cerebral oximetry (NIRS) for high-risk patients; >20% drop from baseline triggers MAP rescue.
End-tidal CO2 maintained 35–45 (hypocapnia + hypotension stacks ischemic risk).
CONTINUOUS communication with the surgeon to release pressure when hemostasis achieved.
- stroke (the feared adverse event)
- MI
- postoperative vision loss (especially ION in spine surgery)
- acute kidney injury
- hepatic ischemia
- delirium
Document the MAP target, the duration, and the indication in the anesthesia record.
End of lecture
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