1) ASA Standards & Pre-oxygenation

ASA Monitoring Standards, application of patient monitors, OR environment & equipment, pre-oxygenation

What is the ASA Standard 1 for Anesthetic Monitoring and why is it needed?

anesthesia personnel continuously present during general, regional, and MAC

• rapid changes in patient status

Describe the 3 types of anesthesia and what they do.

1. General: reaction to stimuli is attenuated to 1%

2. MAC (monitored anesthesia care aka “twilight”): light, patient breaths on their own, and is unresponsive to about 50% of painful stimuli → ex: colonoscopy, biopsy

3. Regional: attenuates nerves in a certain portion of the body

What’s the difference between continuous and continual?

Continuous: at all times → ex: a-line

Continual: at certain intervals → ex: blood pressure

What is the ASA Standard 2 for Anesthetic Monitoring and why is it needed?

Standard 2: during all anesthetics, the patient’s oxygenation, ventilation, circulation, and temperature shall be continually evaluated

• Important to ensure adequate oxygen in the inspired gas and blood, adequate ventilation, adequate circulatory function in the patient, and appropriate body temperature

What are the ways to ensure adequate oxygenation?

1. quantitative: gas analyzer with low oxygen concentration limit alarm (<20% O₂ triggers alarm)

2. quantitative: pulse ox with a variable pitch pulse tone and low threshold alarm (disconnection of circuit of low [O₂] triggers alarm)

3. qualitative: patient’s color

What are the ways to ensure adequate ventilation?

1. quantitative: EtCO2 to verify positioning of ETT or LMA

2. qualitative: chest rise, reservoir breathing bag movement, breath sounds, presence of expired CO₂, volume of expired gas

3. alarm that detects disconnection of breathing system

What are the ways to ensure adequate circulatory function in the patient?

1. quantitative: continuous ECG

2. quantitative: BP and HR < every 5 minutes

3. qualitative: palpate pulse, auscultate heart sounds, A-line, ultrasound peripheral pulse, pulse ox/plethysmography

How can you aid in the maintenance of appropriate body temperature?

Employ warming strategies such as bearhugger, fluid warmer, heated airway humidifier, or warm blankets

Where does lead V5 get placed for ECGs?

5th intercostal space on the anterior axillary line

What’s the difference between capnography and capnometry?

Capnometry (quantitative) measures the concentration of expired CO₂ and capnography describes the wave form of expired CO₂.

Describe pre-oxygenation, why it’s important, and the steps.

de-nitrogenate and fill the lungs with O₂ for a reserve

• APL to sp/min/0

• O₂ flow rate > 10L/min

• good seal of mask

• EtO₂ > 85%

what is malignant hyperthermia

life threatening hypermetabolic reaction

triggers of malignant hyperthermia

volatile anesthetics and succinylcholine

early signs of malignant hyperthermia

increased EtCO2, tachycardia, muscle rigidity

treatment of malignant hyperthermia

stop agents, give dantrolene, support

goal of airway management

maintain patent airway

deliver O2

remove CO2

protect patient from complications

what does head tilt, chin lift do?

moves tongue and soft tissues away from posterior pharynx

when do you use jaw thrust?

when cervical spine is a concern

oropharyngeal and nasopharyngeal airways maintain…

airway patency

what’s bag mask ventilation?

positive pressure ventilation through face mask

indications of difficult bag mask

facial hair

obesity

edentulous

limited jaw movement

airway obstruction

normal BP

120/80

normal MAP

70-100

phase I capnography

little-no CO2 because it measures inspired and anatomical dead space gas

phase II capnography

CO2 rapidly rises as alveolar gas reaches upper airway

phase III capnography

alveolar plateau

where is EtCO2 read on capnography?

upper right corner of plateau

phase IV capnography

inspiration begins and CO2 is cleared

continuous requirements

presence of anesthesia personnel

circuit leak monitor

ECG monitor displayed

continual requirements

pulse ox (oxygenation & circulation)

EtCO2 (ventilation)

temperature

blood pressure (circulation)

what does sudden loss of EtCO2 indicate?

apnea, circuit disconnect, or ETT displacement

rising EtCO2 indicates…

hypoventilation

decreasing EtCO2 indicates…

hyperventilation

reduced blood flow

leak

prolonged expiratory upstroke with no plateau on capnography indicates…

airflow obstruction, bronchospasm

MAP equation

MAP = DBP + (SBP-DBP)/3

arterial blood gas provides…

pH

PaCO2

PaO2

bicarbonate

assign ASA: normal healthy patient, nonsmoking, no alcohol use

ASA I

assign ASA: smoker, social drinker, pregnant, obese (30<BMI<40), well controlled DM/HTN, mild lung disease

ASA II

assign ASA: poorly controlled DM/HTN, COPD, morbidly obese (BMI>40), hepatitis, alcohol abuse, pacemaker, reduced EF, ESRD on dialysis, premature infant, MI, CVA, TIA, CAD (stents) > 3 months ago

ASA III

assign ASA: MI, CVA, TIA, or CAD (stents) < 3 months ago, cardiac ischemia, valve dysfunction, sepsis, disseminated intravascular coagulation (DIC), ARDS, ESRD w/o dialysis

ASA IV

assign ASA: ruptured AAA, massive trauma, intracranial bleed, ischemic bowel

ASA V

assign ASA: brain dead, organs being harvested

ASA VI

if BP cuff is too tight, the measurement will be too…

high

if BP cuff is too loose, BP measurement will be too…

low

when does body temperature need to be monitored?

clinically significant body temps are intended, anticipated, or expected

cases > 30 mins

pt has disease/pre-existing condition

where can you measure temperature?

nose, skin, bladder, esophagus

what does the BP machine actually measure and what does it calculate?

measures MAP, calculates SBP and DBP

pulse ox is an estimate of…

variable arterial hemoglobin saturation

what lights does a pulse ox transmit?

infrared and red light

red light absorbs at…

660nm

infrared light absorbs at…

940nm

oxygenated hemoglobin absorbs…

more infrared light and transmits red light

deoxygenated hemoglobin absorbs…

more red light and transmits infrared light

increases in peak airway pressure indicate…

increased resistance or decreased compliance

ideal tidal volume?

6-8mL/kg

plethysmography

pulse ox wave form