Confusion in the postoperative ward

Published on 10/04/2015 by admin

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Problem 4 Confusion in the postoperative ward

Toby T. Winton-Brown

You are the resident on call covering the night shift and finally about to get some sleep when a concerned nurse pages you requesting a phone order for sedation. A 67-year-old woman has become very agitated 3 days after a left total hip replacement. She has been yelling at the nurses, climbing out of bed and distressing the other patients.

Q.1

What do you tell the nurse over the phone?

This patient evidently has postoperative confusion and needs to be clinically assessed before any psychotropic medication can be given. Over the phone you establish the acuity of the situation – the patient’s vital signs are stable and she is not posing immediate danger to herself or others.

On approaching the ward it is obvious which patient is yours from the noise and commotion. She is half out of bed, clawing at her various drains and lines, and is muttering about the nurses stealing her dentures and poisoning her mashed potato.

Q.2

What might possibly have caused postoperative confusion in this patient? What factors put her at risk?

The patient’s blood pressure is 140/100 mmHG, pulse 100/min and regular, respiratory rate 30/min. Her temperature is 37.7°C. She is on IV fluids, has an indwelling urinary catheter and the fluids chart records a net deficit of 100 mL over the last 24 hours. The operative report records a routine procedure with no complications.

The nurses confirm an acute increase in her confusion over the last 24 hours, which has seemed to fluctuate and particularly worsened during the evening. There is no known history of prior cognitive or psychiatric problems.

When you attempt to examine the patient she becomes angry. She has trouble understanding your questions and is herself difficult to follow. You inspect the surgical wound, which appears clean and non-infected.

Q.3

How would you describe this woman’s clinical state?

Q.4

What investigations will you perform in order to confirm your diagnosis?

Aside from a raised MCV of 104 fL and a GGT of 116 U/L, the results of urinalysis, blood screen and ABGs are normal. The chest X-ray shows a small amount of bibasal atelectasis.

Q.5

What do you think is happening to this patient? What other history would be helpful?

You manage to get the patient’s son on the phone, although it is the middle of night. He is surprised to hear his mother is causing a disturbance – she is usually a quiet lady who keeps to herself since her husband died 5 years ago. He tells you his mother does not often use painkillers or sleeping tablets, but she does ‘drink quite a bit’. He estimates she drinks around a bottle of wine each evening.

Q.6

How does this information affect your assessment? What other information is useful? What is your management plan?

With appropriate management, and regular monitoring of her condition, the patient’s symptoms of delirium due to alcohol withdrawal settle over the next 48 hours.

Q.7

What should be done for this woman before discharge?

After a sensitive chat with you the patient admitted to a habit of drinking that had steadily worsened since her husband’s death some years ago. She has begun socializing less and less and now finds her days mostly oriented around her drinking and admitted she feels quite lonely. She accepts your suggestion of a referral for an assessment at the local alcohol outpatient service and she is discharged 10 days after her operation.

Answers

A.1 You need to establish the acuity of the situation, and the degree of risk to the patient and staff. Do you need to call security, or can you handle this yourself?

On attending the ward you will need to:

• Talk to the nurses to establish the time course, fluctuation and severity of the presenting problems, as well as the background level of cognitive functioning.

• Review the case notes to determine previous episodes, preoperative investigations and any co-morbid diagnoses.

• Review the operative record for any intraoperative difficulties.

• Review the observations chart, fluids chart, medication record and recent investigations.

• Seek a collateral history from relatives if available, particularly regarding pre-existing cognitive function and risk factors that may predispose to confusion.

• Talk to and examine the patient.

A.2 Postoperative confusion is common in the elderly and medically unfit, particularly following orthopaedic and cardiac surgery, occurring in up to 65% of cases. Surgical causes include atelectasis, postoperative wound infection or abscess, complications of anaesthesia and complications specific to the surgery. Postoperative confusion is an instance of delirium, and alongside these factors are the many predisposing and precipitating causes for acute confusion (Table 4.1). Most common are causes of cerebral hypoxia, drugs, infection, pain and iatrogenic factors.

Table 4.1 Predisposing and precipitating factors for delirium

Predisposing Factors

Precipitating Factors

Demographic characteristics

• Age of 65 years or older

Cognitive status

• Cognitive impairment

• History of delirium

Functional status

• Functional dependence

• Low level of activity

• History of falls

Sensory impairment

• Visual impairment

• Hearing impairment

Decreased oral intake

• Dehydration

• Malnutrition

• Treatment with multiple psychoactive drugs

• Treatment with many drugs

• Alcohol abuse

• Sedative hypnotics

• Anticholinergic drugs

• Treatment with multiple drugs

• Alcohol or drug withdrawal

Primary neurologic diseases

• Stroke, particularly nondominant hemispheric

• Intracranial bleeding

• Meningitis or encephalitis

• Orthopaedic surgery

• Cardiac surgery

• Prolonged cardiopulmonary bypass

• Admission to an intensive care unit

• Use of physical restraints

• Use of bladder catheter

• Use of multiple procedures

• Emotional stress

Prolonged sleep deprivation

A.3 The patient’s postoperative confusion is a delirium, variously known as acute confusional state, organic brain syndrome or toxic-metabolic encephalopathy. These are all terms for a clinical syndrome that represents a medical emergency, with significant morbidity and mortality as well as increased length and cost of admission. Delirium should be regarded as a sign of ‘brain failure’, an important signal of a systemic or cerebral emergency with multiple potential causes, that requires immediate diagnosis and treatment. Clinical features are listed in Box 4.1.

Box 4.1

Clinical features of delirium

• Usually over a period of hours or days. Informant often needed to ascertain the time course of onset.

Fluctuating course

• Symptoms recur and relapse over a 24 hour period with characteristic lucid intervals.

• Difficulty focusing, sustaining and shifting attention, manifest in difficulty maintaining conversation or following commands.

Disorganized thinking

• Manifested by disorganized or incoherent speech, rambling irrelevant conversation or an unclear or illogical flow of ideas.

Altered level of consciousness

• Clouding of consciousness, with reduced clarity of awareness of the environment.

Cognitive deficits

• Typically global or multiple deficits in cognition, including disorientation, memory deficits, and language impairment.

Perceptual disturbances

• Delusions or hallucinations in about 30% of patients, particularly visual hallucinations.

Psychomotor disturbances

• Hyperactive, hypoactive and mixed variants. Hypoactive commonly missed.

Altered sleep–wake cycle

• Typically daytime drowsiness, nighttime insomnia, fragmented sleep, or complete sleep-cycle reversal.

Emotional disturbances

• Common – manifested by intermittent and labile symptoms of fear, paranoia, anxiety, depression, irritability, apathy, anger or euphoria.

A.4 Based on the wide range of possible underlying abnormalities you consider the following investigations:

• Urinalysis and glucose dipstick at the bedside.

• FBC looking for anaemia and leucocytosis.

• EUC and LFTs for electrolyte imbalance and liver or renal failure.

• Cardiac enzymes for ischaemia.

• Wound, drain, urine and blood cultures for a source of infection.

• Chest X-ray for infection or atelectasis.

• ABGs for acid–base disturbance.

A.5 There is no obvious postoperative complication or metabolic cause for this patient’s delirium.

The isolated mildly raised GGT and macrocytosis raise a possibility of prior alcohol abuse, and the clinical picture would be consistent with a withdrawal state. Drug withdrawal, such as sleeping pills, can cause a similar picture. Collateral history is essential where information from the patient is hard to obtain or unreliable – now is the time to call the family, even in the middle of the night. Senior advice should always be sought if it remains unclear what is happening (never be afraid to ask!).

A.6 This extra information is consistent with a diagnosis of alcohol withdrawal. Her alcohol intake is likely to be higher than reported by her son.

Once delirium has occurred, treatment is according to the following principles:

• Treat all evident underlying causes promptly.

• Provide supportive care and prevent complications.

• Manage behavioural symptoms.

In this case, treatment of underlying causes should be directed at optimizing fluid balance and treating alcohol withdrawal. Local hospital protocol should be consulted, involving titrated benzodiazepines and parenteral high-dose thiamine to prevent or treat Wernicke–Korsakoff syndrome. Usually a long-acting benzodiazepine, such as diazepam, is given at an initial dose of 10–20 mg orally, and then symptoms of withdrawal are assessed periodically to determine further dosing.

The key to safe and effective alcohol detoxification is regular and repeated assessment, using protocol-based surveillance. Supportive care for delirium should include protecting the airway, maintaining hydration and nutrition, positioning and mobilizing to prevent pressure sores and DVTs and avoiding the use of physical restraints.

Behavioural symptoms of delirium should be treated first with non-pharmacological approaches, creating a calm and orienting environment, with familiar objects and family members, and consistent staff using re-orienting communication. A normal sleep–wake cycle should be encouraged.

Pharmacological treatment should be reserved for when behaviour threatens patient safety or the safety of others. Antipsychotics such as haloperidol and newer agents such as olanzapine and risperidone may be used; however, care should be taken with regard to lowering the seizure threshold, QT prolongation and extrapyramidal effects. As with other medications, the principle of prescribing in the elderly is ‘start low, go slow’.

A.7 The patient should be evaluated for other complications of alcohol abuse (cardiac, hepatic, neuromuscular, respiratory, haematological).

Counselling should address the effects of alcohol abuse on the body, and a formal referral should be made to an appropriate service for further management. An attempt should be made to understand the underlying motivations for continuing to drink. Screening for co-existing mood and anxiety disorders, with their attendant risk of suicide, is a priority. Often there is a family history of alcohol dependence and a vulnerable psychological set that combines with precipitating circumstances leading to dependence. The effectiveness of even very brief interventions in primary care settings to reduce alcohol use has now been established in RCTs, and there are a number of specialized treatments available in secondary settings.

Revision Points

Cardinal Features

• Acute onset.

• Fluctuating cognitive and perceptual disturbance.

• Altered consciousness.

• Underlying medical cause.

Clinical Management

• Treat underlying cause.

• Provide supportive care and prevent complications.

• Use non-pharmacological measures to treat behavioural symptoms.

• Use psychotropics only when necessary for safety – ‘start low and go slow’.

Alcohol Abuse and Dependence

• Common, often covert – high index of suspicion and collateral history often required.

• Hospitalization leads to acute risk of life-threatening withdrawal syndrome and precipitation of Wernicke–Korsakoff syndrome.

• Long-term abuse leads to multiple complications in most organ systems.

• Often co-morbid with depression and/or anxiety, increases risk of suicide.

• Brief interventions can be effective, longer term specialized team approach in some.

Issues to Consider

• What pharmacological treatments are available for alcoholism?

• How would you distinguish delirium from dementia and depression?

• What other nutritional deficiencies can present as a result of chronic alcoholism?

Further Information

, http://emedicine.medscape.com/article/288890-overview. Overview of delirium

, http://www.health.gov.au/internet/alcohol/publishing.nsf/Content/treat-guide. Guidelines for the treatment of alcohol problems

, http://www.anesthesia-analgesia.org/content/102/4/1267.full. Postoperative delirium: the importance of pain and pain management

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