The incidence of postoperative delirium (POD) following major surgery ranges from 17% to
61%.POD is the most frequent neurological complication that can occur in both the young
and old, and its rate is considerably impacted by patient-related risk issues. The
elderly population is believed to be more susceptible to POD, by virtue of being host to
conditions such as a variety of comorbidities, malnutrition, concurrent cognitive
dysfunction, frailty, sensorial and functional deficits, and polypharmacy.
Risk factors for delirium may be further identified as predisposing factors and
precipitating factors. Predisposing factors are those that are present on admission and
are not changeable, e.g. age, number and severity of co-morbid medical conditions,
sensory impairment, history of cognitive impairment, sleep deprivation, immobility, and
dehydration.Precipitating factors are those that trigger delirium while the patient is
hospitalized. These may be infections, constipation, bladder catheterisation, procedures
involving instrumentation, immobility, and sensory impairment
Postoperative delirium, especially in the elderly, significantly compromises patient
recovery and imposes a heavy toll on patient well-being and the healthcare system.
Postoperative delirium has several wide-ranging and adverse outcomes associated with it,
such as mortality, increased length of hospital stay and increased hospital costs.
Several tools have been developed to track changes in mental status that could point to
the onset of delirium. Among the tools employed for this purpose are the Sedation Scale,
the Nursing-Delirium Screening Scale (Nu-DESC), and the Confusion Assessment Method for
the Intensive Care Unit (CAM-ICU).
However, there is a lack of consensus on the use of an appropriate tool to evaluate
delirium in the postoperative period. The 4A's test is a screening instrument that has
been designed for rapid and initial assessment of delirium. It has the added advantage of
evaluating not only delirium but also postoperative cognitive dysfunction (POCD) which is
the second most common complication in elderly surgical patients.
Delirium is a condition that is presumed to be avoidable in 30%-40% of cases which
emphasizes the importance of attention to primary prevention.5 After the onset of
delirium, little can be done to influence its duration, severity, or the possibility of
recurrence. Thus, the necessity for identifying those at risk of developing postoperative
delirium. It is imperative that hospitals should implement multimodal non-pharmacologic
delirium prevention methods to identify and monitor patients at risk of developing this
morbid condition.
There has been scant research in the developing world, including India in the sphere of
postoperative delirium, a condition germane to practically all medical specialities and
especially in the elderly population. Our study will research POD we expect to obtain
evidence that will find the clinical application.
Our study will be focused on evaluating the incidence of POD in the elderly who will be
posted for non-cardiac surgical procedures. We will also assess the association of
postoperative delirium with risk factors such as frailty, cognitive dysfunction, impaired
functional status, presence of comorbidities and polypharmacy. Other postoperative
adverse events such as sedation, pain, postoperative nausea and vomiting will be
recorded. Patient's length of stay in the hospital (LOS), any unanticipated ICU admission
and mortality within 30 days will also be noted.
The following parameters will be recorded in all the patients,
Postoperative delirium: It will be evaluated using 4 A's test, three times in the
first 24 hours postoperatively. A score of 0 suggests absence of delirium or severe
cognitive impairment, score 1-3 suggests presence of possible cognitive impairment,
and a score > 4 suggests the presence of delirium/ cognitive impairment.
Frailty: All eligible patients will be assessed preoperatively using the 9-point
CFS. Score varies from 1-9 with fitness level very fit to terminally ill as depicted
in the table
Cognitive dysfunction: Preoperative cognition will be assessed using the 5-point
Mini-cog test. A score < 4 will be taken as cut-off for impaired cognitive function
Impaired physical mobility: All preoperative mobile patients will be subjected to
Timed Up and Go (TUG) test. A score of <10 s is normal and score of <20 s need
assistance.
Intraoperative hemodynamics (pulse, systolic blood pressure, diastolic blood
pressure, and mean arterial blood pressure) will be recorded every 5-minutes
intraoperatively and every 15-minutes postoperatively in the postoperative care unit
(PACU) till discharge. A mean arterial blood pressure <65 mmHg persisting for
greater than 5-minutes despite treatment will be defined as an episode of
intraoperative hypotension.
Postoperative sedation:Sedation will be assessed postoperatively using the Richmond
Agitation and Sedation Scale. Score varies from +4 to -5 and patient will be
categorised from combative to unarousable as depicted in table.
Postoperative pain will be assessed using the 10-point Numeric Rating Scale (NRS)
Postoperative nausea and vomiting (PONV) It will be assessed using 3-point Likert
scale (0- no nausea and vomiting, 1- nausea only, 2- vomiting)
Length of stay in the hospital and any unanticipated ICU admission will be noted.
All patients will be followed up postoperatively for 30-days and any occurrence of
mortality will be noted.