PACU hypertension

Explain it before you treat it

There is no evidence-based number at which treatment must begin. The consensus statement records insufficient evidence to recommend a general upper limit of arterial pressure at which therapy should be initiated, while noting that pressures above 160 mmHg have been associated with myocardial injury and infarction sessler-2019-d6.

So the first move is not a drug. It is a cause.

The five reversible causes

1. Pain. The commonest, and the one most likely to be under-treated in a patient who cannot yet say so. Treat the pain and re-measure.

2. A full bladder. The guideline asks for assessment of urine output and voiding case by case for selected patients and procedures asa-pacu-2013-d6. Scan the bladder rather than guess. See the urinary retention material on Day 17.

3. Hypercarbia. Hypoventilation from opioid or residual block raises carbon dioxide and drives the sympathetic response. Look at rate and depth, and at the capnograph if there is one.

4. Hypoxemia. Check the saturation and treat it as an airway problem until proven otherwise.

5. Withdrawal of a home antihypertensive. The clonidine label warns that sudden cessation has resulted in nervousness, agitation, headache and tremor accompanied or followed by a rapid rise in blood pressure and elevated plasma catecholamines, more likely at higher doses or with a beta-blocker, and instructs that the drug be continued to within four hours of surgery and resumed as soon as possible afterwards fda-clonidine-label-2022.

Shivering, anxiety, a distended stomach and a cold patient belong on the same list.

Where a threshold does exist

General recommendation. After craniotomy, after carotid endarterectomy because of cerebral hyperperfusion, after aortic or cardiac surgery, and in preeclampsia, the surgical or obstetric service usually sets an explicit upper limit, and that limit is part of the PACU order set. The absence of a general threshold is not the absence of any threshold. Widely taught and not verified against a primary source by this project; it carries no ledger entry. Follow your institution's protocol.

Local practice differs. those limits are institutional; find out what they are before the patient arrives, not after.

If you do treat

General recommendation. The agents usually stocked for this are labetalol in 5 to 10 mg intravenous increments, hydralazine 5 to 10 mg intravenously, and a nicardipine or clevidipine infusion where titratable control is wanted. None has outcome evidence in this setting. Widely taught and not verified against a primary source by this project; it carries no ledger entry. Follow your institution's protocol.

General recommendation. Continue a beta-blocker the patient already takes rather than stopping it. Widely taught and not verified against a primary source by this project; it carries no ledger entry. Follow your institution's protocol.

Note what the guideline says about looking harder: the literature is insufficient to evaluate the impact of cardiovascular assessment and monitoring, or of routine electrocardiographic monitoring, on perioperative complications asa-pacu-2013-d6. Monitoring is not the treatment either.