This Manual of Algorithms may contain some flaws. If in doubt, use your commonsense and revert to thinking from "first principles".

 Constructive criticism is invited - please write with comments to:

Australian Patient Safety Foundation
GPO Box 400


Scroll down this page for Introductory Information


All anaesthesiologists have to manage complex, rapidly evolving, life-threatening crises with little or no warning.

It has long been shown, however, that human beings can only perceive and process information at a finite rate.

In a crisis, events may unfold at a rate which exceeds our capacity to keep pace.

Several studies have shown that not all crises are managed well, including by experienced anaesthesiologists.

It is best, when all is not going well or in crisis situations, to carry out pre-determined sequences of actions which have been shown to be safe and to cater for rare, dangerous problems as well as for more common, mundane ones.

This Manual provides an approach, via a series of easy-to-access Algorithms and Sub-Algorithms, to any crisis which may occur when a patient is undergoing general or regional anaesthesia.

These Algorithms have been derived from and checked against all relevant incidents amongst the first 4000 reported to the Australian Incident Monitoring Study (AIMS). Correctly used, they will guide the anaesthesiologist to an appropriate set of actions and responses in over 99% of applicable incidents.

The responses outlined here have been developed after thousands of hours of analysis of incidents and after seven one or two day meetings, each attended by 60-100 anaesthesiologists. (See the back cover of the hard copy Crisis Management Manual for a brief account of how this Manual came into existence.)

It must always be remembered that no manual will work in every circumstance and a good outcome cannot be guaranteed. Always use your common sense, and revert, if necessary, to working from first principles.


The Manual is based on the mnemonic "COVER ABCD - A SWIFT CHECK", and is designed for use when any patient is undergoing general or regional anaesthesia. It applies whether the patient is ventilated or spontaneously breathing.
The sequence becomes "AB COVER CD - A SWIFT CHECK" when the patient is breathing spontaneously via any mask (including a laryngeal mask), and some components become redundant in certain circumstances.
Examples are given at the end of this section.

The mnemonic serves as a reminder always to cycle systematically through a basic series of thoughts and actions, the intensity of which will depend on the circumstances. This series of thoughts and actions is:

C Circulation, Capnograph, and Colour (saturation)
O Oxygen supply and Oxygen analyser
V Ventilation (intubated patient) (include catheter mount and filter check) and Vaporisers (include analysers)
E Endotracheal tube - Check position, orientation and patency. Always exclude endobronchial intubation.
                                  Palpation of the cuff above the sternal notch while squeezing the pilot balloon will confirm
                                  its position, and slight withdrawal may also resolve desaturation. Patency: ventilate the
                                  tube directly (remove circuit, filter, connections) with a separate system (see
                                 The tip of the tube may have moved, the lumen become obstructed or the cuff herniated into
                                 the lumen or over the end of the tube. If there is any suspicion of regurgitation, aspiration
                                 or obstruction of a tube, perform direct laryngoscopy, suck out the pharynx, adjust the
                                 tube's position, consider adjusting the cuff and pass a suction catheter through the tube.
                                 Don't forget swabs or throat packs.

    and Eliminate machine
R Review monitors and Review equipment

A Airway (with face or laryngeal mask)
B Breathing (with spontaneous ventilation)
C Circulation (in more detail than above)
D Drugs (consider all given or not given)

A Be Aware of Air and Allergy

SWIFT CHECK of patient, surgeon, process, and responses.

The four levels of intensity for each of these components are represented by another, supplementary mnemonic - "SCARE" (SCAN, CHECK, ALERT/READY, EMERGENCY)..

The SCAN sequence should be followed every 5 minutes of any anaesthetic procedure, or more often if necessary. This overcomes the need for special training sessions, as the sequence rapidly becomes second nature and can usually be completed in 40-60 seconds. The CHECK sequence should be used whenever all is not going according to plan, and should also be practised regularly.

Do not hesitate to move on to the ALERT/READY and EMERGENCY  sequences if you are worried, if events are moving quickly, or if it seems that an adverse outcome is possible. These should also be practised from time to time.
Depending on the circumstances, components of each level of  SCARE may be assembled as appropriate, as long as the sequence of COVER is always adhered to. For example, with sudden, severe hypertension, if the first four components of COVER (Circulation, Colour, Oxygen, Oxygen Analyser) are stable and normal at the SCAN level, no further action is required for these. However, it would be desirable to use the CHECK level for the Ventilation, Vaporiser, Review monitors, and Review equipment components of COVER, for the C (Circulation) and D (Drugs) components of ABCD, for the -A (for Awareness) and for SWIFT CHECK (especially with respect to what the surgeon is doing). Hypertension and awareness are two circumstances in which the concentration of volatile agent may need to be increased - whereas for most crises it is left alone at the SCAN and CHECK levels and turned off at the ALERT/READY and EMERGENCY levels.

On the other hand, if, for example, it is suddenly noticed that the patient is pulseless and blue, the full EMERGENCY sequence of COVER should be carried out immediately with progression to any appropriate Sub-Algorithms.

It is important that the basic COVER ABCD sequence is followed before becoming focused on any particular Sub-Algorithm; a major problem is "locking mentally onto" a diagnosis which may not be correct. When assistance is called for, one person should repeatedly cycle through the COVER ABCD sequence and consider other possibilities, whilst the steps in any relevant Sub-Algorithms are followed. Some Sub-Algorithms repeat components of COVER (eg "give 100% oxygen"), usually when the entire sequence does not necessarily have to be followed in full at the outset, whereas others start by instructing anaesthesiologists to ensure that the full COVER sequence has been completed before starting the Sub-Algorithm (eg. that for persistent desaturation, or air embolism).

Although the standard COVER ABCD - A SWIFT CHECK sequence should always be followed, some components become less important or redundant under particular circumstances: for intubated, ventilated patients the A and B after COVER become redundant; for patients breathing spontaneously via any mask, A and B precede COVER, as indicated at the start of this section, and V for Ventilation in COVER becomes redundant. For a patient being ventilated via a laryngeal mask, B becomes redundant; and for a patient breathing spontaneously and receiving oxygen from a source independent of an anaesthetic machine (eg from a wall-mounted flowmeter during regional or intravenous anaesthesia), the V of COVER again becomes redundant.


REMEMBER: Always go through COVER ABCD for ventilated patients and AB COVER CD for patients breathing spontaneously via any mask - followed in each instance by - A SWIFT CHECK. It will be obvious in any particular circumstance which components become redundant.

REMEMBER: Request assistance early on, allocate tasks and calmly coordinate activities, repeatedly cycling through COVER as well as any sub-algorithm/s thought to be appropriate.

There are two differences with regional anaesthesia.
1 At the A for Awareness stage of A SWIFT CHECK: if the patient is sedated or conscious (that is, "Aware"), talk to the patient, and, if concerned, ask them directly how they are feeling.
2 At the CHECK level of A SWIFT CHECK: check the quality and extent of any block, and correlate the estimated extent of sympathetic blockade with any cardiovascular sequelae.




          ETT - Endotracheal tube
          LMA - Laryngeal mask airway


IPPV - Intermittent positive pressure ventilation
PEEP - Positive end expiratory pressure
CPAP - Continuous positive airway pressure
ARDS - Adult respiratory distress syndrome
UWSD - Underwater sealed (chest) drain


ABG - Arterial blood gases
CVC - Central venous cannula
CVP - Central venous pressure
VF - Ventricular fibrillation
VT - Ventricular tachycardia
ECC - External cardiac compression
DIC - Disseminated intravascular coagulation


ETCO2 - End tidal carbon dioxide concentration
FIO2 - Oxygen fraction of the inspired gas
SpO2 - Pulse oximeter saturation readout
BP - Blood pressure
ECG - Electrocardiogram
CVP - Central venous pressure


         ILCOR - International Liaison Committee on Resuscitation
         MH - Malignant hyperthermia