Monitoring in anaesthesia Flashcards
What are the essential vital signs monitored during anesthesia
Essential vital signs include heart rate, blood pressure, respiratory rate, oxygen saturation (SpO2), and temperature.
Why is blood pressure monitoring important in anesthesia?
Blood pressure monitoring is critical to assess the patient’s hemodynamic status, ensuring adequate perfusion of vital organs during anesthesia
: How is respiratory rate typically monitored during anesthesia?
Respiratory rate is often monitored using the anesthesia machine’s ventilator, capnography, and observation of chest movement.
What is pulse oximetry, and what does it measure?
Pulse oximetry is a non-invasive method to measure oxygen saturation (SpO2) in the blood, reflecting the patient’s oxygenation status.
What can cause inaccurate pulse oximetry readings?
Factors such as poor perfusion, movement, nail polish, and external light interference can cause inaccurate SpO2 readings
What does capnography measure?
Capnography measures the concentration of carbon dioxide (CO2) in exhaled air, providing an end-tidal CO2 (EtCO2) value that reflects ventilation.
Why is capnography important in anesthesia?
Capnography is important for assessing the adequacy of ventilation, detecting airway obstructions, and monitoring respiratory status in real-time.
What does an elevated end-tidal CO2 (EtCO2) indicate?
An elevated EtCO2 may indicate hypoventilation, increased metabolic rate, or rebreathing of exhaled gases.
What can cause a sudden drop in EtCO2 during anesthesia?
A sudden drop in EtCO2 may indicate disconnection of the breathing circuit, extubation, or cardiovascular collapse.
What are the normal ranges for end-tidal CO2 (EtCO2)?
Normal EtCO2 levels range between 35-45 mmHg.
What is the purpose of ECG monitoring during anesthesia?
ECG monitoring detects and records the electrical activity of the heart, helping to identify arrhythmias, ischemia, and other cardiac events.
What does the P wave on an ECG represent?
The P wave represents atrial depolarization, the electrical activation of the atria.
What does the QRS complex on an ECG signify?
The QRS complex represents ventricular depolarization, which leads to ventricular contraction.
What does ST-segment elevation on an ECG suggest?
ST-segment elevation may suggest myocardial ischemia or infarction, requiring immediate attention.
How can arrhythmias be identified using ECG in anesthesia?
Arrhythmias can be identified by irregular heartbeats, abnormal QRS complexes, or irregular P waves on the ECG trace.
What are the phases of the capnography waveform?
The capnography waveform has four phases:
Phase I: Baseline (inspiration, no CO2).
Phase II: Expiratory upstroke (beginning of exhalation, CO2 rises).
Phase III: Alveolar plateau (end of exhalation, CO2 levels off).
Phase IV: Inspiratory downstroke (rapid decrease, inhalation start
What does a “shark-fin” pattern on the capnography waveform indicate?
A “shark-fin” pattern (slanted Phase II) on the capnography waveform indicates bronchospasm or airway obstruction, commonly seen in conditions such as asthma or COPD.
What does an absence of a capnography waveform suggest?
An absent capnography waveform suggests either a disconnection in the circuit, a blocked endotracheal tube, esophageal intubation, or no CO2 production (e.g., cardiac arrest).
How is capnography used to confirm correct endotracheal tube placement?
The presence of a continuous capnography waveform after intubation confirms that the endotracheal tube is in the trachea, as exhaled CO2 is detected. Absence of CO2 may indicate esophageal intubation.
How does rebreathing of CO2 affect the capnography waveform?
Rebreathing of CO2 results in an elevated baseline on the capnography waveform, as CO2 is present at the start of the next breath, preventing the baseline from returning to zero
What does a gradually rising EtCO2 trend during surgery indicate
A gradually rising EtCO2 trend may indicate hypoventilation, rising metabolic demands (e.g., fever or sepsis), or rebreathing of exhaled CO2.
What role does capnography play in monitoring during cardiopulmonary resuscitation (CPR)?
During CPR, capnography helps assess the effectiveness of chest compressions and provides early indication of return of spontaneous circulation (ROSC) through sudden increases in EtCO2 levels.
What is Standard 1 according to ASA standards for basic anesthetic monitoring
The anesthesia provider will be present throughout the procedure
What is Standard 2 according to ASA standards for basic anesthetic monitoring
states that the patients oxygenation, ventilation, circulation and temperature will continually monitored
How does a pulse oximeter work?
A pulse oximeter works by emitting red and infrared light through a pulsating arterial bed (such as a fingertip). Oxygenated hemoglobin absorbs more infrared light, while deoxygenated hemoglobin absorbs more red light. The device then calculates oxygen saturation (SpO2) by comparing the absorption of the two wavelengths and uses the pulsatile nature of arterial blood flow to estimate the pulse rate.
