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S Afr Fam Pract
ISSN 2078-6190 EISSN 2078-6204

NWU REFRESHER COURSE

Introduction

Postoperative confusion remains one of the most distressing

complications after an anaesthetic. It is distressing to the health

care professional, to the family and to the recovery room staff.

Delirium has implications on finances, mortality and long-term

outcomes. The complications can be minor but there can also

be physical harm to the patient, dislodgement of catheters

and disruption of the surgical procedure. Although it is more

common in the elderly (> 70 years) and the young (≤ 5years) this

complications can happen at any age group. Some studies have

been done to look at predictors of delirium/confusion in recovery

room and this might help in taking preventative measures for

the at risk patient.

Postoperative confusion may be equated with emergence

delirium as they have a lot of features in common but hopefully

of short duration.

Definition of delirium

DSM five criteria for delirium 1

1. Disturbance in awareness and attention

2. Develops over a short period of hours to days and there

might be fluctuation

3. Disturbance in cognition (memory, language and perception)

4. Disturbance cannot be explained by pre-existing neuro-

cognitive disorder

5. Evidence that the disturbance is due to a direct physiological

consequence of another condition/substance/toxins

Postoperative confusion in recovery room should not be

confused with postop cognitive disorder (POCD) although it can

be viewed as a spectrum of disease process.2

Emergence delirium Postoperative delirium POCD

PACU Within 24 hours-72 hours Weeks- months

Three types of delirium3

1. Hyperactive delirium: restless, combative and agitated
observed in patients with alcohol withdrawal, ketamine
administration and cocaine use.

2. Hypoactive delirium: lethargy, decrease alertness/motor
activity and awareness seen in patients with encephalopathy
from liver failure.

3. Mixed subtype: symptoms may vary depending on time of
day

Pathophysiology5

The mechanism of delirium seems to be unclear and not fully
understood but thought to be multifactorial. Several mechanisms
have been proposed

1. Neurotransmitter theory especially acetylcholine. Levels of
acetylcholine are reduced in the elderly and in a small study
those with low levels had more delirium. This theory is can be
supported by the fact that anticholinergic medications are
known to cause acute confusion.

2. Surgical stress and increase cortisol level

3. Inflammatory mechanism because inflammatory markers
were raised in patients with delirium ( tumour necrosis factor
and interleukin 1 and 6)

4. Intraoperative hypocapnia and cerebral vasoconstriction

5. Increase in noradrenaline levels

South African Family Practice 2016; 58(3):S21-S23

Open Access article distributed under the terms of the
Creative Commons License [CC BY-NC-ND 4.0]
http://creativecommons.org/licenses/by-nc-nd/4.0

Postoperative confusion in recovery room – a practical approach
NR Madima

Specialist Anaesthetist, Department of Anaesthesia, Chris Hani Baragwanath Academic Hospital, University of the Witwatersrand.
Corresponding author, email: nthatheni@tmmc.co.za

Figure 1: pathophysiology of postoperative delirium5

S Afr Fam Pract 2016;58(3):S21-S2322

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Incidence6,7,8,10

The incidence of postoperative delirium is variable depending
on the type of surgery, with reported incidence of 9-65%. Higher
incidences are associated with the elderly with femur fractures
and following cardiac surgery. Many studies have been done to
assess the incidence of postoperative delirium and risk factors
and the incidence varies from12%-50.6%. The incidence of
confusion or delirium in the recovery room has limited studies
with some saying its 20%.

Predisposing factors for postoperative delirium
in PACU3,4,6,8,9,10,13

Patient factors

• Advanced age (>65years)

• Male

• Poor functional status or multiple comorbidities

• Pre-existing delirium, dementia and psychiatric illnesses

• Poor nutritional status

• Visual or hearing defects

Surgical factors3,13

• Long procedures and blood loss with haematocrit less than
30%.

• Orthopaedic fractures: femur fractures are associated with
very high incidence but this may be a reflection of comorbid
diseases as well.

• ENT and head and neck surgeries and this is thought to be a
feeling of suffocation as the patients wake up.

Medications /toxins/metabolic disorders3,8,13

• Alcohol withdrawal

• Medications: long acting benzodiazepines may be associated
with increased risk of delirium compared with short acting
benzos. Other drugs have been associated with delirium are
anticholinergics, antiparkinson (levodopa), antipsychotics
(clozapine), anticonvulsants although there is uncertainty.

• Hypoglycaemia

• Hyponatraemia

Causes of confusion in recovery room 13

• Pain is one the most common causes of confusion in recovery
room. One study found that emergence agitation was 80%
in those with pain compared with 43.5% in those who didn’t
have pain.10

• Metabolic causes: hypoglycemia, hyponatremia, hyper-
natremia, and hypokalaemia.

• Respiratory: hypoxia was found to be associated with delirium
in early studies by Gustafson. Other respiratory causes include
hypocarbia.

• Cardiovascular: hypotension, myocardial ischaemia and
arrhythmias

• Neurological: strokes, seizures and cerebral oedema

• Drugs: benzodiazepines, ketamine, atropine, inhalational
agents especially the newer agents, partial reversal, alcohol
and illicit drug withdrawal.

• Hypothermia

• Surgical factors: sepsis, TURP syndrome and distended
bladder and bleeding.

• Rare causes: malignant hyperthermia, neuroleptic malignant
syndrome and thyroid storm.

Management 3, 8, 13

• Try and reassure the patient and the relatives

• Minimise amount of noise in the recovery room, as this should
be a calm and cheerful environment for patients to slowly
return to normal function.

• Exclude pain as a cause of confusion because patients who
had pain had twice the incidence of postoperative confusion
compared with those who didn’t have pain

• Prevent injuries to the patient and to the recovery room staff

• Assess airway, breathing and circulation, as these are easily
reversible causes. Does the patient need airway protection,
oxygen supplementation or mechanical ventilation? Support
the circulation if BP is low with fluids and vasoactive drugs
while trying to establish a cause.

• Look for a reversible cause and treat the cause

• Do ABG and blood glucose as this may help in establishing a
diagnosis

• Review the anaesthetic chart for medications given
intraoperatively, significant cardiorespiratory events that may
explain the confusion. Reverse or use antidotes if the cause
of the confusion is drug related but be cautious when giving
naloxone, as there is a seizure risk.

• Try to avoid physical restraints, as this may aggravate
confusion and if there is a need for this then the reason need
to be frequently explained to the patient.

• Reunite the patient with family if possible and return
audiovisual aids to the patient as this may calm the patient.

• Other investigations that can be considered if cause is still not
found are FBC, U&E, ECG, CXR and CT scan.

• If still confused and agitated after the above, continue
reassurance, remove urinary catheter and consider some
sedation. Midazolam can be used for sedation in small doses
of 0.5mg -1mg at a time but caution need to be exercised as
there can be paradoxical excitation.

• Haloperidol can be given in small doses if hallucinations
persist using 0.5 mg intravenous boluses until the patient is
calm. Patient can be sent to the ward on maintenance doses
of haloperidol to be over a few days.

• Remember some of the patients with recovery room confusion
will recover spontaneously but sadly recovery room delirium
predicts POCD with 100% sensitivity and 85% specificity.

Confusion in paediatric patients in the recovery room
(a short word)

The confused agitated child in recovery room is very distressing
to the recovery room staff, parents and the anaesthetist. This
phenomenon may give an impression that the anaesthetic was
not good enough.11

Postoperative confusion in recovery room – a practical approach 23

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The two most common causes of confusion in recovery room are

pain and drug induced emergence delirium. Before saying that

the child is diagnosed with emergence delirium some serious

causes need to be excluded.11

Some of the causes that need to be excluded are the same as

those discussed in adult population above.

Hypoxia, pain, hypoglycemia and hypothermia are common in

the paediatric patient and need to be excluded in any child who

is restless and look confused in recovery room.

The lecture will not discuss emergence delirium (ED) in detail

but this phenomenon has been in existence since 1960s. The

incidence of ED varies from 10-80% but generally 10-50%

depending on the definition, anaesthetic drugs and surgical

procedure. 12

Risk factors are ages 1-5 years, preoperative anxiety, ENT and

oral surgery, postoperative pain and the use of newer fast

acting inhalational agents.12 When risk factors exist preventative

pharmacological measures should always be considered to avoid

this stressful complication despite its self-limitation.

Confusion in children in recovery room should be approached as

in the adult population ruling out hypoxia, hypoglycaemia and

trying to find a cause and the same time continual reassurance to

the care givers that there is no lasting effects from the confusion.

In conclusion confusion or emergence delirium in recovery room
is very stressful needing a lot of staff to manage the patient and
possibly depriving care from other patients. It is also stressful to
the family with longer stay in recovery room, hospital stay and
in some patients may lead to post operative delirium and POCD.

References

1. DSM 5, American society of psychiatry; 2013

2. Jeffery Silverstein. Central nervous dysfunction after noncardiac surgery and
anaesthesia. Anesthesiology 2007; 106, 622-628

3. TN Robinson. Postoperative delirium in the elderly: diagnosis and management.
Clinical interventions in aging. 2008; 3(2) :351-353

4. J Mantz. Case scenario: postoperative delirium in elderly surgical patients.
Anesthesiology. 2010; 112: 89-95

5. M Bitsch. Pathogenesis and management strategies for postoperative delirium
after hip fracture. Acta orthopaedica Scandinavia. 2004; 75(4) 378-389

6. E Marcantonio. Delirium is an independently associated with poor functional
recovery after hip surgery. Journal of American geriatric society. 2000; 48(6)
618-624

7. C Lepouse. Emergence delirium in adults in the post anaesthetic care unit. BJA.
2006; 96(6) 747-753

8. Postoperative delirium in the PACU. www.anaes.ucla.edu

9. RD Sanders. Risk factors for postoperative delirium. Lancet psychiatry. 2014;1(6)
404-408

10. D Yu, W Chai. Emergence agitation in adults: risk factors of 2000 patients.
Canadian journal of anaesthesia. 2010; 57:843-848

11. J Shung. The agitated child in recovery room. SAJAA. 2011; 17: 96-99

12. G Vlajkovic. Emergence delirium in children: many questions, few answers.
Anaesthesia and analgesia. 2007; 104: 84-91

13. C Nickson. Postoperative confusion. lifeinthefastlane