Monitoring in anesthesia Flashcards
what is monitoring
To watch & check a situation carefully for a period of time
what are the standards for basic anesthetic monitoring (2)
- standard I
- standard II
why do we monitor
Maintain normal patient physiology and homeostasis throughout the period of anesthesia
what does standard I state
it states that an anesthesia provider will be present with the patient throughout the anesthetic
what does standard II state
that the patients oxygenation, ventilation, circulation and temperature will be continually monitored
what is monitored during oxygenation (2)
- inspired oxygen
- blood oxygenation
how is oxygenation measured (2)
- hemoglobin saturation with a pulse oximeter
- observation of the skin
what is monitored during ventilation (2)
- qualitative clinical skills
- chest excursion
- auscultation of breath sounds (using a precordial or esophageal stethoscope)
- movement of the reservoir bag.
- Patients who are breathing spontaneously should be observed for signs of airway obstruction, including a tracheal tug, paradoxical chest movement, snoring, or upper airway sounds. - quantitative monitoring
- capnography ( CO2 concentration in exhaled breath)
how should mechanical ventilation be monitored
with an audible disconnet monitor
during ventilation how should tracheal intubation be verified (2)
- clinically
- by detection of exhaled CO2 (capnography)
how do you monitor circulation (3)
- ECG
- blood pressure measurement at least every 5 minutes
- continuous monitoring of peripheral circulation by:
- palpation
- auscultation
- plethysmography ( tool which measures changes in volume within an organ)
- arterial pressure
how do you monitor temperature
thermometry
what factors can interfere with the pulse oximeter (4)
- Shivering
– movement may make it difficult for the probe to pick up a signal. - Pulse volume
– the oximeter only detects pulsatile flow. When the blood pressure is low due to hypovolemic shock or the cardiac output is low or the patient has an arrhythmia, the pulse may be very weak and the oximeter may not be able to detect a signal. - Vasoconstriction
- it reduces blood flow to the peripheries. The oximeter may fail to detect a signal if the patient is very cold and peripherally vasoconstricted. - Carbon monoxide poisoning
- gives a falsely high saturation reading. Carbon monoxide binds very well to haemoglobin and displaces oxygen to form a bright red compound called carboxyhaemoglobin. This is misinterpreted by the oximeter as oxyhaemoglobin and the oximeter may read 100%, even though the true oxygen saturation is very low and the patient may be very hypoxic. This is only an issue in patients following smoke inhalation from a fire
A sudden increase in carbon dioxide production on a capnogram is the first warning sign for
malignant hyperthermia
A sudden drop in expired carbon dioxide on a capnogram is the first sign of what (2)
- pulmonary artery embolism
- air embolism
what does a capnograph do (4)
- can diagnose obstruction of the natural or artificial airways
- measures the expired CO2 conc
- helps determine whether tracheal or esophageal intubation was performed (if its normal looking )
- a sudden rise/ drop in expired CO2 can provide warning signs for certain conditions
what changes in CO2 elimination cause an increase in ETCO2 (4)
- hypoventilation
- rebreathing
- partial airway obstruction
- laparoscopy