Monitoring in anaesthesia Flashcards
(22 cards)
Define monitoring.
To watch & check a situation carefully for a period of time
Why do we monitor patients during anaesthesia?
Maintain normal patient physiology and homeostasis throughout the period of anaesthesia
What does Standard I of basic anaesthetic monitoring state?
States that an anaesthesia provider will be present with the patient throughout the anaesthetic.
What is measured during oxygenation?
Inspired gas and Blood oxygenation using pulse oximeter
What does Standard II of basic anaesthetic monitoring state?
States that the patient’s oxygenation, ventilation, circulation and temperature will be continually monitored.
Give 4 factors that interfere with the pulse oximeter reading?
Shivering, Pulse volume, Vasoconstriction, Carbon monoxide poisoning, Dark nail polish, Improper placement of pulse oximeter
What 2 things do you monitor on ventilation?
Qualitative clinical signs- Chest rising, how fast a patient is breathing, auscultation of breath sounds, snoring, tracheal tug
Quantitative monitoring- Capnography
What does a capnogram show?
The amount of CO2 being exhaled
What are sudden increase and decrease in expired carbon dioxide signs of?
increase in CO2 - malignant hyperthermia
decrease in CO2 - PE and air embolism
What causes an increase in CO2 intra-op?
CO2 elimination- hypoventilation, rebreathing, partial airway obstruction, laparoscopy
CO2 production- fever, thyroid storm, malignant hyperthermia
What causes an decrease in CO2 intra-op?
CO2 elimination- hyperventilation, hypoperfusion, pulmonary embolism
CO2 production- hypothermia
What 2 things do you monitor on circulation?
Qualitative clinical signs- skin colour, temperature, palpable pulse, heart tones
Quantitative methods- BP, ECG
How big should a correct BP cuff be?
Width of the cuff should be 1.5 times limb diameter and should occupy at least 2/3 of the arm.
What happens if the wrong BP cuff size is used?
Selection of appropriate cuff size is important because a tight cuff leads to false high readings, while a Loose cuff gives false Low readings.
What can cause a reading error/failure when taking BP?
- Pressure line is disconnected.
- Leakage from damaged cuff.
- Line is compressed (under someone’s foot or under a weal).
- Line contains water from washing!
- Monitor error: cuff cannot inflate due to infant or neonate limits.
Which 3 pulses should be felt and what systolic BP do they equate to?
Palpation of Radial A → systolic BP ˃ 90 mmHg.
Palpation of Dorsalis Pedis A → systolic BP ˃ 80 mmHg.
Palpation of Superficial Temporal A → systolic BP ˃ 80 mmHg.
How is temperature monitored?
Clinical monitoring: ur hands.
Monitors: temperature probe: nasopharyngeal, esophageal.
What 2 types of info does an ECG provide for the clinician?
(1) heart rate,
(2) cardiac rhythm
(3) information about possible myocardial ischemia (via ST segment analysis)
What is invasive arterial blood pressure monitoring and when is it indicated?
It is beat to beat monitoring of ABP via an arterial cannula.
Indicated in major surgeries ,during deliberate hypotensive anesthesia during the use of inotropes, cardiac surgery in surgeries involving extreme hemodynamic changes/instability eg. pheochromocytoma, repeated ABG sampling.
Why is it necessary to avoid hypothermia? (complications of hypothermia) < 36 degrees celsius
Cardiac arrhythmias: VT & cardiac arrest.
Myocardial depression.
Delayed recovery (delays drug metabolism).
Delayed enzymatic drug metabolism.
Metabolic acidosis (tissue hypoperfusion → anerobic glycolysis → lactic acidosis) & hyperkalemia.
Coagulopathy.
Give 4 other things to look out for.
Movement, facial expressions
Nerve stimulators
Gas monitoring
Blood loss
Urine output
CNS awareness
What the 5 rules never to forget?
Never start induction with a missing monitor: ECG, BP, SpO2.
Never remove any monitors before extubation & recovery.
NEVER ignore an alarm by the ventilator.
ALWAYS remember than ur clinical sense & judgement is better than & superior to any monitor. U are a doctor u are not a robot. The monitor is present to help u not to be ignored and not to cancel ur brain.
ALWAYS remember that there is NO such thing as “all monitors disconnected” → check that ur pt is ALIVE!! Immediately check peripheral & carotid pulsations to make sure that ur pt is not ARRESTED!! Once u have ensured pt safety reattach ur monitors once again.
