Syncope : Causes , Investigations , Management

 Syncope :

Syncope is a sudden and transient loss of consciousness which is followed by recovery.

Question to ask:

Will this patient need admission?

Will this patient require further investigations and Follow Up ?

Are there any underlying serious causes for the syncope and that need immediate Treatment

Causes :

These include the following :

Vaso vagal syncope :

This usually occurs in the young people and may be due to a number of factors.

Overwarm environment

Prolonged standing

Sudden fright or emotion

Prolonged Starvation

Large meals

Alcohol

Usually there are premonitory symptoms of feeling yn well , nauseated , dizzy or tired , with visual symptoms like visual blurring.

Relief may be obtained by telling the affectee to sit down or lie down with feet elevated.

Was it an epileptic seizure ?

Usually occurs rapidly and develops into generalized tonic clonic convulsions.

Frothing from the corner of the mouth , urinary incontinence and tongue biting may be present.

Post seizure confusion is common.

If a witness is present , it would be a good idea to get an account of the events from the witness.

Cardiac Causes:

Cardiac causes of syncope are also sudden in onset and are accompanied by pallor and sweating and may recover rapidly followed by flushing.

Associated palpitations may be present.

Ask about Chest pain and paliptations and cardiac medications like GTN / Glyceryl nitrare.

Some cardiac patients prone to syncope include

Paroxysmal AF / Atrial Fibrillation.

HOCM / Hypertrophic Obstructive Cardiomyopathy

Seizures / Epilepsy :

We need to exclude any epilepsy that might have caused the syncope.

Hypoglycemia :

Low blood sugars can lead to syncope as well.

Management:

If patient loses consciousness in A & E

Assess pulse

Attache Cardiac Monitor and Oximeter

Clear airway

Give oxygen to maintain levels more than 90 %

Do an ECG

Check BM Levels

Check blood pressure , Temperature.

Treat as per findings

Try to get a history of syncope from witnesses.

Examine the patient.

Look for any tongue biting or focal neurological signs.

Also examine the heart for murmur or any arrhythmias.

Do an ECG to look for arrhythmias or evidence of myocardial ischaemia

Lying standing BP should be checked.

Perform a chest X ray and look for lung fields and cardiac size.

Also check Urea and electrolytes, creatinine levels and any evidence of sepsis

Check Haemoglobin levels.

Check blood sugar levels

Send sepsis screen

Further management:

Patients with simple syncope may be discharged

Those with underlying causes / Seizures or cardiac causes shpuld be admitted and investigated further.

TCA POISONING / TRICYCLIC ANTIDEPRESSANT POISONING :

 TCA POISONING / TRICYCLIC ANTIDEPRESSANT POISONING :

This is usually caused by Tri cyclic Antidepressants poisoning like

Amitryptiline

Imipramine

Dothiepin

But it may also occur due to other medications such as Atropine and Procyclidine.

Atropine is also present in Atropa Belladona ( deadly Nightshade )

Clinical Features :

Common Features include :

Tachycardia

Hot Dry skin

Dry mouth

Drowsiness leading to Coma

Dilated pupils

Ataxia

Urinary retention

Jerky limb movements.

Unconscious patients will have divergent squint ,

Increased muscle tone

Increased Reflexes,

Myoclonus and

Extensor plantar responses.

In deep coma, there will be muscle flaccidity with no detectable reflexes and respiratory depression requiring IPPV.

Convulsions occur in 10 percent of unconscious patients and may precipitate cardiac arrest.

Patients recovering from coma often suffer  delirium and hallucinations and have jerky limb movements and severe dysarthria.

ECG Findings :

Sinus tachycardia is usual.

But as the severity of poisoning increases, the PR interval and the QRS complex also increases.

Theese changes may help  confirm the clinical diagnosis of tricyclic poisoning in an unconscious patient.

The p wave maybe superimposed on the preceding  T wave giving the impression of VT  when the rhythm is actually sinus tachycardia with prolonged conduction.

In very severe poisoning ventricular arrhythmias and bradycardia can occur especially in patients who are hypoxic.

Death may result from cardiorespiratory depression and acidosis.

Management :

Clear Airway

Maintain ventilation.

Give supportive treatment and provide nursing care.

Observe continuously as the patient has the potential for rapid deterioration.

Monitor ECG during gastric lavage or unconscious patients or post ictal patients.

Perform gastric lavage if less than 1 hour since overdose or longer and if patient is in coma.

Activated charcoal should be given.

Single brief fits do not warrant any treatment but iv diazepam should be given in case of prolonged fits.

Most cardiac arrhythmias occur in the patients of TCA overdose while they are unconscious within a fe hours of overdose..

These can usually be treated in most cases by correction of Hypoxia and Acidosis.

8.4 % of sodium bicarbonate ( 50 – 100 ml in adult ) ( 1ml/kg in child ) may produce a dramatic improvement in cardiac rhythm and output.

This is achieved by altering protein binding and reducing active free Tricyclic drug.

Avoid anti arrhythmic drug

Donot use physostigmine salicylate  or flumazenil which ca precipitate fits.

Unconscious patients usually improve over 12 hours and rgain consciousness with in 36 hours

Delirium and hallucinations may persist over 2 -3 days

And may require sedation in large doses with diazepam ( 20 – 30 mg PO every 2-3 hours )

Aspirin / Salicylate Poisoning

 Aspirin / Salicylate Poisoning

One standard Aspirin tablet contains 300 mg of Acetyl salicylic acid

Ingestion of 150 mg/kg body weight produces mild toxicity.

Ingestion of 500 mg/kg body weight produces severe toxicity and fatal poisoning.

Ingestion of salicylate ointment from the skin can also produce toxicity.

Clinical features of Salicylate poisoning:

Tinnitus

Hyperventilation

Vomiting

Deafness

Sweating

Vasodilatation

Dehydration

Hypokalemia

In severe poisoning

Coma

Convulsions

Confusion

Children usually develop :

Hyperpyrexia and

Hypoglycemia

Rarer features include :

Non cardiogenic pulmonary oedema

Renal failure and 

Cerebral oedema

Metabolic and Acid Base features :

These include mixed Metabolic acidosis and Respiratory Alkalosis

But respiratory features predominate.

In a few childreand and adults , acidosis predominates and is often associated with  confusion or coma.

Management

Gastric lavage if the adult had ingested more than 4.5 Gm of Acetyl salisylic acid ( 15 tablets ) in the last 1 hour.

If the adult has ingested more than 4.5 Gm of Acetyl salicylic acid, 50 Grams of harcoal should be put in the stomach via the NG tube to reduce the absorption of Acteyl salicylic acid and to increase its elimination.

In children , if they have ingested more than 2 Grams , 25 Grams of charcoal should be put into the stomach.

Plasma salicylate concentration should be measured and repeated aftera few hours again as well.

This is because salicylate levels may increase due to continuing absorption.

In case of signs of severe poisoning or CNS Features , Plasma glucose levels, Urea and Electrolytes and Arterial Blood Gas levels should also be checked.

Mild poisoning :

Childern with plasma salicylate of less than 350 mg /l ( 2.5 mmol/l ) and adults with plasma salicylate levels of less than 450 mg /l ( 3.3mmol/l )  only need increase oral fluids to treat raised salicylate levels.

Moderate poisoning:

Children with salicylate levels of more than 350 mg/l and adults with salicylate levels of more than 450 mg/l will need iv fluids for correction of dehydration and elimination of salicylate.

Measure plasma salicylate levels and measure after a few hours again if symptoms recur as salicylate absorption may be ongoing.

Sodium bicarbonate 1.26 % ( 500 ml /hour , 3 hourly ) can correct metabolic acidosis and increase the elimination of salicylate as well as it alkanizes the urine and is superior to massive diuresis in elimination of salicylates.

Urinary pH should be more than 7.5 ( ideally 8.0 – 8.5 )

Repeated doses of Charcoal should be given.

Check Urea & Electrolytes, ABGs and serum potassium levels.

Repeat salicylate levels as needed.

Get urgent specialist  advice.

Consider urgent referral for Haemodialysis.

Salicylate Levels of more than 700 mg/L or 5.1 mmol/litre , CNS features are suggestive of severe toxicity and warrant seeking of urgent specialist advice and Haemodialysis.

Correct acidosis and give repeated charcoal by N/G tube.

IPPV may help in extreme hyperventilation with paralysis and and in life threatening poisoning with Coma

Haemodialysis removes salicylates and corrects electrolyte Imbalances.

Give additional glucose since brain glucose maybe low despite normal blood glucose concentrations.

In life threatening  poisoning with coma and extreme hyperventilation paralysis , IPPV may help while haemodialysis removes salicylates and corrects the electrolyte disturbances.