2-7

Tachycardia

Tachycardia in theatre is often due to inadequate depth of anaesthesia / analgesia or alternatively a reflex to hypotension. Tachycardia should not be treated as an isolated variable: remember to tailor treatment to the patient and the situation. Follow the full steps to exclude a serious underlying problem.

START.
1
Immediate action
2
Adequate oxygen delivery
3
Airway
4
Breathing
5
Circulation
6
Underlying problems
7
Rate control
8
Escalate
9
Depth
Box A CRITICAL TACHYCARDIA

If no pulse, delegate one person (minimum) to chest compressions and → 2-1 Cardiac arrest.

If hypotension worsening or impending arrest, consider electrical cardioversion (Box D).

Box B POTENTIAL UNDERLYING PROBLEMS

Stimulation with inadequate depth.

Consider drug error.

Also consider: central line/wire; hypovolaemia; primary cardiac arrhythmia; myocardial infarction; electrolyte disturbance; local anaesthetic toxicity (→ 3-10); sepsis (→ 3-14); circulatory embolus, gas/fat/amniotic (→ 3-5); anaphylaxis (→ 3-1); malignant hyperthermia crisis (→ 3-8)

Box C DRUGS FOR TACHYCARDIA

Fluid bolus 10 ml.kg⁻¹ (adult 250 ml)

Magnesium 50 mg.kg⁻¹ (adult 2 g) over >10 min, max conc. 200 mg.ml⁻¹

Amiodarone 5 mg.kg⁻¹ (adult 300 mg) over >3 min, NOT in polymorphic VT

Labetalol 0.5 mg.kg⁻¹ (adult 25–50 mg), repeat when necessary

Esmolol 0.5 mg.kg⁻¹ (adult 25–50 mg)

Adenosine 0.1 to 0.5 mg.kg⁻¹ (adult 3 to 18 mg) – for SVT

Box D ELECTRICAL CARDIOVERSION

Attach pads and ECG from defibrillator.

Ensure adequate depth / sedation / analgesia for cardioversion.

Engage synchronisation and check for sync spikes on R-waves.

Start with 1 J.kg⁻¹ (adult 50–100 J) biphasic.

Remember to hold shock button until sync shock delivered.