EXPLICIT AND IMPLICIT AWARENESS DURING ANESTHESIA

EXPLICIT AND IMPLICIT AWARENESS DURING ANESTHESIA

😐(Explicit = Fully and clearly expressed)

😐(Implicit =Implied or understood though not directly expressed)

😐The incidence of awareness is around 0.1–0.2%

😐Explicit Awareness is intentional or conscious recollection of prior experiences as assessed by tests or recall or recognition, which are also called direct memory test.

😐Implicit Awareness is perception without conscious recall. The patient denies recall, but may remember “something” under hypnosis.

😐Awareness (deliberate)
Surgery conducted under local or regional anaesthesia. During some neurosurgical procedures, the patient is woken up to assess whether surgery has affected, or will affect, important areas.

😐STAGES OF AWARENESS ( Griffith and Jones )

1. Conscious perception with explicit memory;
2. Conscious perception without explicit memory;
3. Dreaming;
4. Subconscious perception with implicit memory;
5. No perception and no implicit memory.

😐CAUSES

🔻may result from a failure of the apparatus to deliver adequate concentrations of anesthetic agent. Such failures include leaks, faulty or empty vaporizers, a misconnected or disconnected breathing system, inaccurate pumps, misplaced venous cannula and occluded infusion tubing

🔻may result from a failure of the clinician  to monitor the concentrations of inspired and expired volatile agents may result in inadequate anesthetic agent being delivered. TIVA is more difficult to monitor in this respect.

🔻may result from an inadequate dosing of the anesthetic agent as represented by the alveolar concentration (it is important to remember that the MAC value that is quoted is only the MAC 50 ) or the computed blood concentration in target-controlled infusion (TCI).

🔻may result from an altered physiology or  pharmacodynamics in the patient e.g. Anxiety may increase dose requirements

🔻may result from the wearing off of the induction agent during a difficult intubation sequence or with the anesthetic techniques for rigid bronchoscopy

😐CLINICAL SIGNS

🔻In the spontaneously breathing patient who is not paralyzed, awareness may be manifest by purposeful movement.

🔻Sympathetic stimulation: the main clinical signs are tachycardia, hypertension, diaphoresis and lacrimation; but their absence does not exclude awareness.  Attempts have been made to quantify these objectively by using the PRST scoring system (blood Pressure, heart Rate, Sweating, Tear formation)..

😐SEQUELAE:

Commonest is the occurrence of a post-traumatic stress syndrome, whose typical features may include nightmares, insomnia, panic attacks and agoraphobia.

😐CHECKLIST FOLLOWING A COMPLAINT OF AWARENESS DURING GENERAL ANAESTHESIA

1. Visit the patient as soon as possible, along with a witness (Preferably a consultant)
2. Take a full history and document the patient’s exact memory of events
3. Attempt to confirm the validity of the account
4. Keep your own copy of the account
5. Give a full explanation to the patient
6. Offer the patient follow-up, including psychological support, and document that this has been offered
7. Reassure the patient that they can safely have further general anaesthetics, with minimal risk of a further episode of awareness
8. If the cause is not known, try to determine it
9. Notify your medical defence organisation
10. Notify your hospital administration
11. Notify the patient’s GP

#awareness , #ptsd , #AnesthesiaComplications , #TheLayMedicalMan , From www.facebook.com/drunnikrishnanz , partial reference from frca.uk , #anaesthesia