2-5

Hypertension

Hypertension is most commonly due to inappropriate depth of anaesthesia or inadequate analgesia. You should rapidly exclude a problem in adequate oxygen delivery, airway and breathing first.

START.
1
Immediate actions
2
Adequate oxygen delivery
3
Airway
4
Breathing — exclude hypoxia and hypercarbia as causes
5
Circulation
6
Depth
7
Underlying problem
8
Escalate
Box A CRITICAL CHANGES

If problem worsens significantly or a new problem arises, call for help and go back to START of 1-1 Key Basic Plan.

Box B POTENTIAL UNDERLYING PROBLEMS

Inadequate anaesthesia / analgesia (alfentanil can be diagnostic – see Box C for dose)

Inadequate neuromuscular blockade

Consider whether you could have made a drug error

Omission of usual antihypertensives

Distended bladder

Vasopressor administered by surgeon

Surgical tourniquet

Excess fluid (over-administration / overload / TURP syndrome)

Medical causes: drug interaction, renal failure, raised intracranial pressure, seizure, thyrotoxicosis, phaeochromocytoma

Box C TEMPORISING DRUGS FOR HYPERTENSION

Alfentanil 10 µg.kg⁻¹ (adult 0.5–1 mg)

Propofol 1 mg.kg⁻¹ (adult 50–100 mg)

Labetolol 0.5 mg.kg⁻¹ (adult 25–50 mg). Repeat when necessary.

Esmolol 0.5 mg.kg⁻¹ (adult 25–50 mg). Follow with infusion.

Hydralazine 0.1 mg.kg⁻¹ (adult 5–10 mg)

Glyceryl trinitrate 0.5–5 µg.kg.min⁻¹ infusion (adult 2–20 ml.hr⁻¹ of 1 mg.ml⁻¹ solution)