Anaesthesia And Pain Relief Flashcards
IV anaesthetic agents
1- propofol
2- thiopentone
3- etomidate
4- ketamine
“PTEK”
Propofol
Can be used as a continuous infusion
Thiopentone
Rapid induction.
But can cause myocardial depression and lowering of BP.
Lowering of intracranial pressure makes it useful for neurosurgery.
Etomidate
Brief duration of action.
But can cause adrenocortical depression(it is a steroid)
Ketamine
Ideal choice for field anesthesia.
Can cause Emergence Delirium.
Enhanced Recovery Programmes
Adequate preoperative care. Multidisciplinary approach. Good choice of anesthesia.
Triad of General Anesthesia
1- amnesia (loss of awareness)
2- muscle relaxation
3- analgesia : pain relief
Induction is frequently done by
IV propofol
Maintenance is done by
IV propofol or inhalational agents such as sevoflurane. Isoflurane. Desflurane.
Induction in children, needle phobic adults, and those in which difficult airway is anticipated
Inhalational induction by sevoflurane
Rapid Sequence Induction(RSI)
Predetermined dose of IV propofol and rapidly acting muscle relaxant such as suxamethonium.
Used in those in which there is high risk of regurgitation.
In emergency surgery.
Non- emergency surgery of those who have delayed stomach emptying.
Total Intravenous Induction(TIVA)
IV propofol and ultra short acting opioid remifentanil.
Used in neurosurgery. Airway laser surgery. Cardiopulmonary bypass. Day case surgery.
Why nitrous oxides has been discontinued
Post operative nausea and vomiting.
Increases size of air bubble in eye. Ear and abdominal surgery.
Mutagenic and powerful greenhouse gas.
Things to manage in General Anesthesia
Airway
And
Ventilation
Airway management in general anesthesia
During induction airway is managed by oropharyngeal airway.
After induction, endotracheal tube or laryngeal mask airway.
Pros of laryngeal mask airway
Less irritable to patient and less traumatic
Difficult intubation by endotracheal tube can be managed by
Fibrooptic Intubating bronchoscope
Pros of endotracheal tube
Provision of cuff causes positive pressure and protects the lungs from aspiration
Ventilation used during intubation
Bag mask ventilation
Ventilation used after induction
Spontaneous or ventilator assisted.
Ventilator assisted ventilation can either be
1- volume controlled
2- pressure controlled
3- positive end expiratory pressure(PEEP)
Volume controlled ventilation
Allows adequate air entry but risks high pressure damage especially in laparoscopic surgery, morbidly obese patients and lung disease patients who can’t withstand Barotrauma
Pressure controlled ventilation
Prevents high pressure damage but at the risk of inadequate airway entry.
PEEP
Allows alveoli to remain open and prevents vascular shunting
It maintains the functional residual capacity (FRC)
Double lumen tubes and endobronchial tubes
Allow collapse of one lung while ventilating the other lung
Guedal airway
Tongue remains out but risk of aspiration is still there.