Transcript Slide 1

Postoperative
Delirium
Presented By:
Tareq Salwati SSC-Anaes
Case Summary 1:
27 years old lady, comes for debridement
and skin grafting.
She receives a balanced TIVA anesthetic,
using propofol infusion and fentanyl.
After extubation she became agitated, and
combative.
Case Summary 2:
A 23-year-old previously healthy man undergoes
general anesthesia for distal upper extremity
surgery.
The surgery and anesthetic progress uneventfully.
After emergence and extubation and on
transport to the postanesthesia care unit
(PACU), the patient becomes disoriented and
combative.
Problem Analysis
Definition
Postoperative delirium is a state in which a
patient has alterations in mental status
that range from disorientation and lethargy
to violent, harmful behavior and confusion.
These patients are awake, but cannot or do
not follow commands appropriately.
Recognition
Multifactorial Occurrence
-Postoperative delirium is a multifactorial
occurrence that needs to be promptly evaluated
by an anesthesiologist whether on table, or in
the PACU.
-It also may only be a sign of a more lifethreatening problem, such as airway obstruction,
hypoxia or hypercarbia, which must be
diagnosed immediately.
Possible Sequelae
-A significant sequela of postoperative delirium is
that the patient is at extreme risk of physically
harming himself or PACU personnel.
-If the patient becomes combative, he or she may
cause accidental trauma to self or the staff, and
surgical repairs or indwelling lines and catheters
may be in jeopardy.
-Furthermore, the agitation may also produce a
large sympathetic nervous system response
leading to hypertension and tachycardia.
Patient Assessment
After restraining the patient, assess the patients
preexisting medical condition, perioperative
medications administered, course of anesthesia,
and type of surgery performed.
Next, a thorough physical examination and
laboratory evaluation addressing arterial blood
gas, serum glucose concentration, and
electrolytes should follow.
If a diagnosis is not forthcoming, a neurologic
consultation and computed tomographic (CT)
head scan should be considered.
Risk Assessment
-Postoperative delirium is not a rare occurrence in
the immediate postoperative period.
-It has been established that children and young
adults are more likely to be agitated after
emergence.
-Young children can often be calmed by the
presence of a parent in the PACU.
-Furthermore, elderly patients are at substantially
higher risk of having prolonged recovery of
cognitive function after emergence, and thus
may respond inappropriately in the PACU.
-Any patient with preoperative personality
disturbances will generally have the same after
emergence.
-Patients with language, cultural or ethnic
differences may have difficulty responding
appropriately to PACU staff.
-Finally, patients who have undergone surgical
procedures with possibly grave consequences
(e.g., tumor biopsies) may emerge with
heightened agitation.
Implications
The consequences of postoperative delirium are
twofold:
-First, identifying the cause and treating that
appropriately, and
-second, calming and carefully positioning and
restraining the patient to avoid injury to himself
or others.
The former requires efficient, precise diagnosis
and treatment to offset possible sequelae.
Management
Emergence Phenomena
The most likely reason for development of postoperative
delirium is a transient period after emerging from general
anesthesia during which the patient is unable to respond
to sensory input appropriately.
-A wide range of variation occurs among the responses,
from somnolence and quiescence to hysteria and
uncontrolled thrashing.
-A patient with the latter will need calming, positioning, and
restraint, all of which may escalate the state of
restlessness.
-As noted above, airway obstruction, hypoxia, or
hypercarbia must be immediately assessed and treated
if present.
Anticholinergic Crises
-Anticholinergics have historically been a major contributor
to emergence delirium when given parenterally.
-Both atropine and scopolamine, when administered
perioperatively, may lead to postoperative disorientation.
-They may concomitantly produce tachycardia, facial
flushing, and dry mouth.
-Moreover, anticholinergic medications administred ocularly
for pupillary dilataion have also been implicated in
causing emergence delirium.
-Treatment consists of administering physostigmine
1.25 mg IV.
Perioperative Meperidine
-Perioperative meperidine (pethidine) in
large doses, because of its atropine-like
structure, can also cause these symptoms
(i.e., similar to anticholinergic crises).
-Furthermore, long term meperidine use
may lead to build-up of normeperidine, its
major metabolite, which has substantial
convulsive properties.
Other Perioperative Medications
-Other perioperative medications that may
produce disorientation on emergence include
long-acting benzodiazepines (e.g., diazepam,
lorazepam)
-and the induction agents ketamine, etomidate,
and propofol.
Ketamine is probably the most widely recognized
agent that causes postoperative dysphoria and
hallucinations.
Propofol has been implicated in induction of
seizure activity in rare incidences
-Insufficient or lack of reversal of
neuromuscular blockade may produce
severe agitation and uncoordinated,
disoriented movement.
A patient will lack strength and purposeful
movement and may need sedation and
mechanical ventilation until the
neuromuscular blockers are metabolized,
if more reversal agent is not indicated.
Alcohol and Recreational Drugs.
-Acute perioperative intoxication with alcohol
or recreational drugs and/or withdrawal
from such agents must be considered.
Pain and Discomfort
-Patients who awaken after general
anesthesia with substantial pain may be
highly agitated prior to the administration
of analgesics.
-Distension of the stomach or the urinary
bladder, poor body positioning,
inappropriately tight dressings or traction,
and any indwelling catheters or lines can
also cause discomfort and agitation.
Metabolic Alterations
-Hypothermia increases the solubility of inhalational
anesthetics, decreases metabolism of numerous
sedative medications, and, if severe enough (<30
degrees centigrade), may produce cold narcosis.
-Serum glucose concentrations must be evaluated, as
hypoglycemia is readily treatable with 50% glucose
administration IV.
-Hyperglycemia, especially diabetic ketoacidosis and
hyperosmolar, nonketotic coma may alter the mental
status of the patient.
The latter disorder is diagnosed by high blood glucose
concentrations (>600 mg/dL), hyperosmolarity, and lack
of ketoacidosis.
Metabolic Alterations
Furthermore, hyperglycemia often occurs in patients
without diabetes mellitus but with some type of severe
illness ( sepsis, pneumonia, large burn).
It may also occur with substantial dehydration, IV dextrose
administration, or large dose steroid administration.
-The coma that results from this disorder is most likely due
to cerebral intracellular dehydration.
Treatment is in the intensive care unit setting with insulin
administration, hydration, potassium supplementation,
and close monitoring of glucose concentration and
electrolytes.
Neurologic Injuries and Conditions
-Careful neurologic examination and consultation may be of
great value.
Cerebral hypoxia leading to ischemia may occur secondary
to prolonged hypoxemia or hypotension.
-Trauma patients may develop unrecognized increased
intracranial pressure or hemorrhage.
-Intracranial hemorrhage may also occur due to large,
abrupt hypertension in the perioperative period.
-Cerebral thromboembolism may occur in many patients,
especially those with known carotid vascular disease or
those having undergone cardiac, vascular or radical
neck surgery.
Neurologic Injuries and Conditions
Although rare, placement of intra-arterial, internal jugular or
subclavian lines could cause thromboembolism.
-Air embolism in cardiac surgery, air injection of intraarterial lines, or intraveinous air administration in a
patient with right-to-left shunt (paradoxical air embolism).
-Fat embolism producing cerebral ischemia is very rare, but
it should be considered in patients with long bone
fractures.
-Computed tomographic scans may be an invaluable aid in
all of these situations.
-Finally, unrecognized grand mal seizures due to an
underlying seizure disorder or delirium tremens
secondary to alcohol withdrawal must be considered.
Treatment of Postoperative
Delirium
-Treatment of postoperative delirium , because in
most cases it is transient, is usually supportive.
-Patient reassurance, a quiet, calm environment,
and close observation during the short interval
required for dissipation of general anesthetic
effects are often all that is necessary.
-Nevertheless, more substantial intervention, such
as the administration of analgesics for pain, or
small doses of short-acting sedatives to relieve
anxiety, may be required.
-Likewise, a patient may need to be
restrained if agitation could cause harm to
self or others in the PACU.
-It must be reiterated that close observation
and evaluation of all other possible
medical reasons for the altered mental
status must be performed prior to the
administration of medications that may
further alter a patients sensorium.
Prevention
-Because it is difficult to predict in which patient
postoperative delirium will develop, preventing it,
necessitates careful perioperative care of the
patient, from preoperative assessment through
discharge from the PACU.
-A caring, dedicated PACU staff, who attempt to
calm and reassure the patient while the medical
evaluation progresses, is invaluable.
THANK YOU!
Source:
Chapter 47-48
Complications in anesthesia
John L. Atlee, M.D.
1999