Bradycardia during Anesthesia

Bradycardia during Anesthesia

Definition:

-Pulse rate less than 60 beats/min. in adults

-Pulse rate less than 80 beats/min. in infants

-Pulse rate less than 100 beats/min. in neonates

Causes and Management:

1-Hypoxia:

-Late response is bradycardia

Treatment:

-Of the cause, Oxygenation, Anticholinergics

2-Drug induced:

-High concentration volatile anesthetics, Opioids, Succinylcholine, Anticholinesterases (Neostigmine), Low dose atropine (Benzold-Jarisch reflex, paradoxical bradycardia), β-blockers, Digoxin

Treatment:

-Decrease concentration of volatile anesthesia, Anticholinergics

3-Vagal stimulation:

- Airway instrumentation, Visceral traction, Extraocular muscle traction, Anal dilatation, Cervical dilatation

Treatment:

-Stop traction or dilatation, Anticholinergics

4-Spinal anesthesia:

-High spinal anesthesia affecting T1-T4 (Cardiac accelerator fibers)

Treatment:

-Support circulation, Anticholinergics, Ephedrine (if associated with hypotension)

5-Ischemic heart disease:

-Ischemic changes affecting conducting system

Treatment:

-Anticholinergics if indicated

6-Endocrine disease:

-Hypothyroidism

Treatment:

-Anticholinergics

7-Metabolic:

-Hyperkalemia

Treatment:

-Correction of potassium level, Anticholinergics

8-Neurological:

-Cushing’s reflex due to increased ICP

Treatment:

-Of the cause, Anticholinergics if indicated

9-Cardiovascular fitness:

-Trained athlete (High resting vagal tone, Large stroke volume)

N.B.: Anticholinergic drugs (Atropine, Glycopyrrolate, Hyoscine)

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Tachycardia during Anesthesia

Tachycardia during Anesthesia

Definition:

-Pulse rate greater than 100 beats/min. in adults

Causes and Management:

1-Light anesthesia, Pain:

-Hypertension, sweating, lacrimation, reactive pupils, movement 

Treatment: Deepening the anesthesia, Analgesia 

2-Drug induced:

-Anticholinergic drugs, Catecholamines, Oxytocin 

3-Hypovolemia:

-Actual (due to fluid loss): 

Treatment: Fluid replacement 

-Effective (due to vasodilatation): 

Treatment: Vasopressors (α-agonists, Ephedrine) 

4-Hypercarbia:

Treatment: Check soda lime, Increase minute ventilation, and Exclude malignant hyperthermia 

5-Hypoxia:

-Initial response is tachycardia 

Treatment: Of the cause

6-Cardiac dysrhythmia:

-SVT: 

Treatment: Of the cause, Carotid sinus massage, Adenosine, Verapamil, Amiodarone, Digoxin 

-VT: 

Treatment: Of the cause, Lidocaine, Amiodarone, Synchronized DC (if sustained or hemodynamically unstable) 

7-Endocrine disease:

-Pheochromocytoma, Thyrotoxic crisis 

Treatment: α-blockers, β-blockers 

8-Sepsis:

9-Malignant hyperthermia:

-First sign is tachycardia 

Treatment: According to management guidelines

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