Monitoring in Anaesthesia

Question 1

What is the primary purpose of monitoring in anaesthesia?

Answer 1

To warn of any impending disaster and ensure the well-being of the patient.

Question 2

What is the difference between continuous and continual monitoring?

Answer 2

Continuous monitoring occurs without interruption, while continual monitoring is repeated at regular intervals.

Question 3

What are the two main types of monitoring?

Answer 3

Non-invasive and invasive monitoring.

Question 4

For which types of anaesthesia is monitoring recommended?

Answer 4

Monitoring is recommended for all general, regional anaesthesia, and monitored anaesthetic care.

Question 5

What is the standard for basic intraoperative monitoring?

Answer 5

Presence of qualified anaesthetic personnel throughout the procedure.

Question 6

What are the key parameters evaluated in intraoperative monitoring?

Answer 6

Oxygenation, ventilation, circulation, and body temperature.

Question 7

What are the types of monitoring methods used during surgery?

Answer 7

Clinical and equipment monitoring.

Question 8

What is the importance of continuous anaesthetist presence during surgery?

Answer 8

To immediately respond to any changes in the patient’s condition.

Question 9

Name the standard monitoring equipment used in anaesthesia.

Answer 9

ECG, blood pressure, precordial stethoscope, capnography, pulse oximeter, temperature, and urine output.

Question 10

How is respiratory system monitoring conducted clinically?

Answer 10

By observing colour, movement of the reservoir bag, chest excursion, and auscultation.

Question 11

What is the function of a pulse oximeter?

Answer 11

To non-invasively measure oxygen saturation in arterial blood and pulse rate.

Question 12

How does a pulse oximeter work?

Answer 12

It uses differential wavelengths of red and infra-red light absorbed by deoxy-haemoglobin and oxy-haemoglobin.

Question 13

What is the normal oxygen saturation range measured by a pulse oximeter?

Answer 13

97–100%.

Question 14

How does the presence of oxygenated blood affect pulse oximeter readings?

Answer 14

It increases the absorption of infra-red light.

Question 15

What does a low reading on a pulse oximeter indicate?

Answer 15

It may indicate the presence of more deoxygenated blood or issues such as difficult intubation.

Question 16

What does the plethysmograph on a pulse oximeter show?

Answer 16

It shows the volume of blood flow during systole.

Question 17

What information does the pulse oximeter display?

Answer 17

Pulse rate and oxygen saturation of the blood.

Question 18

Name different types of pulse oximeter probes.

Answer 18

Probes include LED, ear, finger, toe, and bridge of the nose types.

Question 19

What does pulse amplitude indicate on a plethysmograph?

Answer 19

It indicates tissue perfusion.

Question 20

What factors can affect the accuracy of a pulse oximeter?

Answer 20

Factors include COHb, metHb, probe position, peripheral vasoconstriction, ambient light, dyes, and nail polish.

Question 21

List some common problems associated with pulse oximetry.

Answer 21

Problems include no direct info about O2 delivery, response time lag, and skin pressure sores.

Question 22

Why is an oxygen analyser essential in anaesthesia?

Answer 22

To monitor the fraction of inspired oxygen (FiO2) in the gas mixture.

Question 23

What is capnography, and what does it measure?

Answer 23

Capnography measures expired CO2 concentration and assesses ventilation adequacy.

Question 24

What are the two types of sampling used in capnography?

Answer 24

Mainstream and sidestream.

Question 25

How does capnography assess ventilation adequacy?

Answer 25

By showing the concentration of CO2 in the exhaled breath.

Question 26

What are the clinical uses of capnography?

Answer 26

Measures respiratory rate, identifies oesophageal intubation, and allows ventilation adjustments.

Question 27

What are the phases of capnography?

Answer 27

Phase I: Dead space gas; Phase II: Dead space + alveolar gas; Phase III: Alveolar gas; Phase IV: Inspiration.

Question 28

What are the normal ETCO2 values?

Answer 28

3.5 – 5.7 kPa.

Question 29

List some factors that can increase ETCO2.

Answer 29

Rebreathing, hypoventilation, sepsis, malignant hyperthermia, thyroid storm.

Question 30

List some factors that can decrease ETCO2.

Answer 30

Disconnection, cardiac arrest, pulmonary embolism, hyperventilation, hypoperfusion, hypothermia.

Question 31

What are some common capnography tracing abnormalities?

Answer 31

Elevated baseline (rebreathing), slow phase II rise (COAD), curare cleft (recovery from NMB).

Question 32

What is the purpose of an O2 failure warning device?

Answer 32

It provides an auditory alarm, cuts off anaesthesia gas supply, and switches circuits to air.

Question 33

What does a precordial stethoscope monitor?

Answer 33

It monitors the position of the endotracheal tube, ventilation, heart sounds, and rhythm.

Question 34

What is an oesophageal stethoscope, and when is it contraindicated?

Answer 34

An oesophageal stethoscope can also measure core temperature but is contraindicated in oesophageal varices.

Question 35

What clinical signs are monitored in the cardiovascular system?

Answer 35

Pulse rate, rhythm, volume, heart sounds, and extremity perfusion.

Question 36

What does an electrocardiogram (ECG) monitor?

Answer 36

Electrical activity of the heart.

Question 37

What are the uses of ECG in anaesthesia?

Answer 37

To determine heart rate, diagnose arrhythmias, and detect ischaemia.

Question 38

What are some inaccuracies that can occur with ECG monitoring?

Answer 38

Poor electrode placement, muscle activity, and electromagnetic interference.

Question 39

What does arterial blood pressure reflect in a patient?

Answer 39

Reflects organ blood flow, with systolic, diastolic, and mean arterial pressure values.

Question 40

What are the different methods for detecting arterial blood pressure?

Answer 40

Palpation, auscultation, oscillotonometry, and plethysmography.

Question 41

What are the complications of invasive arterial pressure monitoring?

Answer 41

Haematoma, thrombosis, infection, nerve damage, and inadvertent drug injection.

Question 42

What does central venous pressure (CVP) indicate?

Answer 42

It reflects the blood volume (preload) and right heart function.

Question 43

What are the indications for measuring CVP?

Answer 43

Fluid management, venous access, caustic drug infusion, TPN, and air embolism aspiration.

Question 44

What complications can arise from CVP monitoring?

Answer 44

Air embolism, dysrhythmias, pneumothorax, nerve damage, tamponade, and infection.

Question 45

Why is monitoring urine output important during surgery?

Answer 45

To monitor kidney function and manage fluid balance.

Question 46

How can the depth of anaesthesia be clinically assessed?

Answer 46

Through Guedel's stages, and signs of sympathetic stimulation.

Question 47

What is the BiSpectral Index (BIS) used for?

Answer 47

To monitor the depth of anaesthesia using EEG and EMG technology.

Question 48

What is the purpose of neuromuscular junction monitoring?

Answer 48

To assess neuromuscular block and response to nerve stimulation.

Question 49

What are the standard sites for core temperature measurement?

Answer 49

Lower oesophagus, tympanic membrane, nasopharynx, bladder, and rectum (unreliable).

Question 50

How is blood loss monitored during and after surgery?

Answer 50

Through clinical signs, gravimetric measurements, and visual estimates.