The order
Danger first, then frequency and reversibility. Say it aloud: oxygen and carbon dioxide, circulation, glucose, paralysis, drug, temperature and sodium, brain.
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Oxygenation and ventilation. Saturation, respiratory rate, chest movement, capnograph. Take a blood gas if the carbon dioxide is a question. These kill in minutes and are already on the monitor.
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Circulation. Blood pressure and rhythm. A brain that is not perfused does not wake.
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Glucose. A meter answers in seconds. General recommendation. Give dextrose for a low reading rather than waiting for the laboratory. Widely taught and not verified against a primary source by this project; it carries no ledger entry. Follow your institution's protocol.
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Residual paralysis. A quantitative monitor answers in seconds and the patient cannot tell you. The guideline sets a train-of-four ratio of 0.9 or more as recovery and recommends quantitative monitoring over clinical assessment thilen-2023. Sugammadex is dosed by measured depth: 2 mg/kg at the reappearance of the second twitch, 4 mg/kg at one to two post-tetanic counts fda-sugammadex-label-2026.
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Residual drug. Volatile, opioid, benzodiazepine, and the central anticholinergic syndrome. See the reversal agents below.
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Temperature, sodium and the other electrolytes.
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The brain. Pupils, focal signs, imaging. Last because it is rarest and least reversible, not because it does not matter.
The order is expert consensus, not a trial result ellis-2017.
The reversal agents, and their traps
Naloxone. For postoperative opioid depression the label gives increments of 0.1 to 0.2 mg intravenously at two to three minute intervals to the desired degree of reversal. Because the duration of action of some opioids exceeds that of naloxone, whose adult serum half-life ranged from 30 to 81 minutes in one study, the patient must be kept under continued surveillance and repeat doses given as necessary fda-naloxone-label-2023. General recommendation. Smaller increments of 0.04 to 0.1 mg are widely used to avoid abrupt reversal. Widely taught and not verified against a primary source by this project; it carries no ledger entry. Follow your institution's protocol. Abrupt reversal may cause nausea, vomiting, sweating, tachycardia, hypertension, seizures, ventricular arrhythmias, pulmonary edema and cardiac arrest fda-naloxone-label-2023.
If you give naloxone, you have committed to watching the patient for longer than the naloxone lasts.
Flumazenil. 0.2 mg intravenously over 15 seconds, repeated at 60-second intervals up to four further doses, maximum 1 mg. Re-sedation occurred in 3% to 9% in conscious-sedation studies and the terminal half-life is 40 to 80 minutes fda-flumazenil-label-2025. The boxed warning: seizures are most frequent in patients on benzodiazepines for long-term sedation, or in overdose with signs of serious cyclic antidepressant overdose fda-flumazenil-label-2025. Ask what the patient takes at home before you give it.
Physostigmine, for central anticholinergic syndrome, once the commoner causes are excluded. In a recovery-room study it was diagnosed in 18 of 962 patients (1.9%) after prolonged anesthetic or relaxant effect, respiratory depression and metabolic disorder were excluded; all woke after physostigmine and six relapsed and needed a second dose link-1997. General recommendation. The usual dose is 0.5 to 2 mg intravenously given slowly, with atropine available for bradycardia and an awareness of its seizure risk. Widely taught and not verified against a primary source by this project; it carries no ledger entry. Follow your institution's protocol.
Do not
Do not skip to the brain. Do not stop before it either.
Sources
[[fda-naloxone-label-2023]] advisory 2023 n: NA open
Naloxone Hydrochloride Injection, USP [prescribing information]. Hospira, Inc. Revised 07/2023. DailyMed set ID 8535cc84-ad4a-4d67-8480-fb5a2e3406f8.
FDA label. Dosage and Administration: 'Since the duration of action of some opioids may exceed that of naloxone, the patient should be kept under continued surveillance. Repeated doses of naloxone should be administered, as necessary.' Pharmacokinetics: 'the serum half-life in adults ranged from 30 to 81 minutes (mean 64 +/- 12 minutes).' Postoperative opioid depression: 'increments of 0.1 to 0.2 mg intravenously at two to three minute intervals to the desired degree of reversal.' Precautions: abrupt reversal may cause nausea, vomiting, sweating, tremulousness, tachycardia, increased blood pressure, seizures, ventricular tachycardia and fibrillation, pulmonary edema, and cardiac arrest.
[[fda-flumazenil-label-2025]] advisory 2025 n: NA open
Flumazenil Injection, USP [prescribing information]. Fresenius Kabi USA, LLC. Revised January 2025. DailyMed set ID a72d9fc1-121c-455d-93a9-002378c9968f.
FDA label. Boxed warning (WARNINGS): 'THE USE OF FLUMAZENIL HAS BEEN ASSOCIATED WITH THE OCCURRENCE OF SEIZURES. THESE ARE MOST FREQUENT IN PATIENTS WHO HAVE BEEN ON BENZODIAZEPINES FOR LONG-TERM SEDATION OR IN OVERDOSE CASES WHERE PATIENTS ARE SHOWING SIGNS OF SERIOUS CYCLIC ANTIDEPRESSANT OVERDOSE.' Reversal of sedation/anesthesia (adults): 0.2 mg IV over 15 s; further 0.2 mg at 60-s intervals up to 4 additional doses; maximum cumulative 1 mg. Resedation 3% to 9% in conscious-sedation studies; terminal half-life 40 to 80 minutes.
[[link-1997]] cohort 1997 n: 962 paywalled
Link J, et al. Distinct central anticholinergic syndrome following general anaesthesia. Eur J Anaesthesiol. 1997 Jan;14(1):15-23.
Prospective 2-month recovery-room study: 18/962 (1.9%) developed distinct central anticholinergic syndrome after other causes (prolonged anaesthetic/relaxant action, respiratory depression, metabolic disorder) were excluded; 6/60 women after hysterectomy (P=0.003); untreated somnolence >2 h in 6/18; all woke after physostigmine, 6 relapsed and needed a second (one a third) dose.
[[thilen-2023]] guideline 2023 n: NA open
Thilen SR, Weigel WA, Todd MM, Dutton RP, Lien CA, Grant SA, Szokol JW, Eriksson LI, Yaster M, Grant MD, Agarkar M, Marbella AM, Blanck JF, Domino KB. 2023 American Society of Anesthesiologists Practice Guidelines for Monitoring and Antagonism of Neuromuscular Blockade. Anesthesiology. 2023 Jan 1;138(1):13-41.
TOF ratio >=0.9 is the stated recovery threshold; quantitative monitoring recommended over qualitative/clinical assessment; sugammadex recommended for deep, moderate and shallow rocuronium- or vecuronium-induced block; neostigmine described as a reasonable alternative only from minimal block (TOF ratio 0.4 to <0.9); patients with documented quantitative TOF ratio >=0.9 do not require pharmacologic antagonism
[[fda-sugammadex-label-2026]] advisory 2026 n: NA open
Sugammadex Injection [prescribing information]. Fresenius Kabi USA, LLC. Revised 6/2026. DailyMed set ID 8e685b67-6804-4d97-b43e-0259b3fe231f.
FDA label. Dosing by depth: 2 mg/kg at reappearance of T2; 4 mg/kg at 1-2 post-tetanic counts; 16 mg/kg ~3 min after 1.2 mg/kg rocuronium. Anaphylaxis 0.3% (1/299 healthy volunteers, in the 16 mg/kg group). 'Cases of marked bradycardia, some of which have resulted in cardiac arrest, have been observed within minutes after the administration.' Recurrence: lower-than-recommended doses increase risk of recurrence after initial reversal. Hormonal contraceptives: equivalent to a missed dose; additional non-hormonal contraception for 7 days. Waits before re-dosing steroidal NMBA: 5 min (1.2 mg/kg rocuronium), 4 h (0.6 mg/kg rocuronium or 0.1 mg/kg vecuronium), 24 h after 16 mg/kg or in renal impairment.
[[ellis-2017]] consensus statement 2017 n: NA open
Ellis TA 2nd, et al. Delayed Emergence From Anesthesia: A Simulation Case for Anesthesia Learners. MedEdPORTAL. 2017 Sep 18;13:10628.
Educational simulation case (not a study): lists causes of delayed emergence as residual anesthetics, pharmacologic actions, surgical complications, neurologic events, endocrine disturbances, patient factors; emphasises pseudocholinesterase deficiency. Design vocabulary has no term for an educational resource; 'consensus_statement' is a placeholder the director should confirm or the row should be dropped from support and kept as found_via only.