AIR (AND OTHER) EMBOLISM

LOOK FOR (1)

A sudden fall in ETCO2
Desaturation and/or central cyanosis
Air in surgical field or vascular line
Hypotension
A sudden change in spontaneous breathing pattern
A change in the heart rate
A change in the ECG configuration
Raised CVP or distended neck veins
A cardiac murmur or mottled skin

EMERGENCY MANAGEMENT

Inform the surgeon (2)
Prevent further entrainment/infusion of gas (3)
Flood the field with fluid
Aspirate central venous line if already in situ
100% oxygen and hand ventilate
Consider valsalva or PEEP
Level the patient
Do not hesitate to treat as a cardiac arrest
Turn the vaporiser off
If hypotensive:
     -Volume expansion with crystalloid 10 ml/kg
     -Consider adrenaline initial bolus 0.1 mg IV (adults); in children 2.0 mcg/kg IV (4).
          Repeat if necessary or follow with an infusion 1mg in 100ml burette, start at 60mls/hr (adults)
          For a generally useful adult catecholamine infusion preparation see the bottom lines
             of the  adrenaline dosage calculations page in this manual (4)
.         For children adrenalin infusion dosages,

FURTHER CARE

Careful postoperative review of the patient to:
     Confirm nature/source of embolism (3)
     Stabilise long bone fractures
     Consider admission to ICU
If there is confirmed cerebral gas embolism
     Consider lignocaine infusion, commencing at 0.06 mg/kg/min. IV
     Early hyperbaric oxygen therapy (within at least the first 4-6 hours and sooner if possible)

NOTES:
Ý Top

The figures reported here are based on an analysis of 38 of the first 4000 AIMS anaesthesia incidents. A further discussion of this algorithm is presented in the associated series of papers on crisis management during anaesthesia (www.qshc.org).

It was judged that correct use of the algorithm would have led to earlier recognition of the problem and/or better management in 41% of the 38 relevant incidents reported to AIMS.

(1) The following changes were documented in the AIMS reports: A fall in ETCO2 68%, desaturation - 60%, hypotension - 36%, a change in heart rate - 24%, a change in ECG configuration - 27%.
(2) In the AIMS reports, in 22% the source of embolus was via intravascular lines. The remainder (78%) were from the surgical field, most commonly: intracranial, hepatobiliary and maxillofacial.
(3) Sources of embolism include:
     (a) Entrainment of air, from venous sinuses or large veins; high risk procedures include those where the operative site
           is above the level of the right atrium. Spinal and intrathoracic procedures may also be implicated.
     (b) Infusion of air or carbon dioxide; from "unprimed" vascular lines such as warming coils or infusion devices,
           insufflation of body cavities, "pressure" operated dissection devices and re-use of part empty blood bags..
     (c) Thrombotic embolism; most commonly from pelvic veins.
     (d) Fat embolism; occurring after any trauma, or long bone surgery.
(4) In some reported embolism cases, noradrenaline has been effective (P. Mackay, personal communication).