crisp and clear, practically oriented ppt on awareness under anaesthesia, intended for anaesthesia practitioners.

1. Accidental Awareness under
general Anesthesia(AAGA).
Dr. Venkataprasad MD.

2. • Anesthesia is drug induced reversible loss of
consciousness, amnesia, analgesia, immobility
along with physiologic support.
not all or none phenomenon.
Awareness generally occurs when there is an
imbalance between the depth of anesthesia and
the stimulus to which a patient is exposed.

4. • the overall published incidence of awareness
(with or without pain) has steadily decreased
from 1.2% in the 1960s to around 0.15%.

5. Ghoneim MM, Block RI, Haffarnan M, Mathews MJ. Awareness during anesthesia: risk factors, causes and
sequelae: a review of reported cases in the literature. Anesthesia and Analgesia 2009; 108: 527–35.
• Inability to move.
• Hearing voices.
• Feeling of helplessness.
• Pain.

6. Pandit JJ, Andrade J, Bogod DG, et al. 5th National Audit Project (NAP5) on accidental awareness during general
anaesthesia: summary of main findings and risk factors. British Journal of Anaesthesia 2014; 113: 549–59.
• Contributing factors for (AAGA)
• Neuromuscular blocking drugs.
• Difficult airway.
• Rapid sequence induction.
• Interruption of anesthetic delivery.
• Typically include cardiac surgery, emergency or
trauma surgery and Caesarean section.
• Increased anesthetic requirement.

7. Mashour GA, Shanks A, Tremper KK, et al. Prevention of intraoperative awareness with explicit recall in
an unselected surgical population: a randomized comparative effectiveness trial. Anesthesiology.
2012;117:717–725
• Equipment and drug delivery errors:
Inadequately filled vaporizers.
failure to turn the vaporizer on.
breathing system disconnections.
“tissuing” of intravenous cannulae,
disconnection of infusion lines or pump
malfunction / misuse.

8. Monitoring depth of Anesthesia
Clinical parameters.
• Hypertension, tachycardia, lacrimation, pupillary
dilatation and sweating.
• Medications.
Anticholinergic
anti-hypertensive
anti-anginal medications
Hypothyroidism.
Autonomic neuropathy.
Limited cardiac reserve.

9. • ETAG concentration MAC
• Avidan et al. 2008 & 2011 have suggested that
a protocol in which ETAG alarms are turned on
and set to 0.7 age-adjusted MAC is associated
with a low incidence of AAGA.

10. EEG based monitors.
BIS
PSI score.
Narcotrend.

12. Cochrane review (Punjasawadwong et al., 2007; updated in 2010).
Mashour GA, Shanks A, Tremper KK, et al. Prevention of intraoperative awareness with explicit recall in an unselected
surgical population: a randomized comparative effectiveness trial. Anesthesiology. 2012;117:717–725
NAP 5 2014.
• A Cochrane review concluded that BIS-guided
anaesthesia could reduce the risk of AAGA when
compared with clinical signs, but not with end
tidal anaesthetic gas monitoring.
• Mashour et al. published a larger RCT of 18,836
patients, and again reported no significant
difference between BIS and end-tidal anesthetic
gas monitoring.

13. Brice interview
• 1. What was the last thing you remembered happening
before you went to sleep?
• 2. What was the first thing you remembered happening
on waking?
• 3. Did you dream or have any other experiences whilst
you were sleep?
• 4. What was the worst thing about your operation?
• 5. What was the next worst thing?

14. Samuelsson P, Brudin L, Sandin RH. Late psychological symptoms after awareness among
consecutively included surgical patients. Anesthesiology 2007; 106: 26–32.
Sequelae of AAGA
Nightmares, flashbacks and anxiety .
Sleep disturbances, fear of future anesthetics,
tendency to avoid necessary medical care.
Post traumatic stress disorder.

15. NAP 5 support pack for AAGA

16. . Myles PS. Prevention of awareness during anaesthesia. Best Pract Res Clin Anaesthesiol 2007; 21: 345–55summary
Summary
• Rare but devastating complication.
• Most AAGA is avoidable, and the incidence
can be reduced by 50% through audit and
education.
• Depth of anesthesia monitors an option in
high risk patients.
• Early detection of impact and follow up.