Monitors, Circuits, and Machines Flashcards
Standard ASA Monitors
Standard 1: qualified person
Standard 2:
a. Oxygenation - pulsox
b. Ventilation - ETCO2
c. Circulation - EKG, blood pressure, HR
d. Body Temp
What is a-ADO2?
What is the normal value?
Difference between ETCO2 and PaCO2
Nrml value: 2-5 mmHg
What causes an increase in a-ADO2?
Age Emphysema Pulmonary embolism Decreasing CO Hypovolemia Anesthesia
What causes a decrease in a-ADO2?
Large Tidal Volumes
Low Frequency Ventilation
Causes of Decreases ETCO2
A. Decrease in metabolic rate
- Hypothermia
- Hypothyroidism
B. Change in elimination
- Increased dead space/COPD
- Hyperventilation
- Decreased CO/ cardiac arrest
- Decreased CO2 production
- Circuit leak or occlusion
- PE
C. Other
- Increased muscle relaxation
- Increased depth of anesthesia
- wedging of the PA catheter
Causes of Increased ETCO2
A. Increased metabolic rate
- increased CO2 production (MH, thyrotoxicosis, hyperthyroidism)
- hyperthermia
- shivering or convulsions
B. Change in elimination
- rebreathing (valve prolapse, failed CO2 absorber)
- hypoventilation
- depression of respiratory center with decrease in Tidal Volume
- reduction of ventilation (partial paralysis, high spinal, weak respiratory muscles, acute respiratory distress)
C. Other
- excessive catecholamine production
- administration of blood or bicarb
- release of aortic/arterial clamp or tournaquet
- parenteral hyperalimentation
- glucose in IV fluid
- CO2 in peritoneal/thoracic/joint cavity
- subcut Epi injection
Causes of minimal to zero ETCO2 or sudden drop to near zero
- equipment malfunction
- ETT disconnect, obstruction, or total occlusion
- bronchospasm
- no cardiac output
- cardiac arrest
- bilateral pneumothorax
- massive PE
- esophageal intubation
- application of PEEP
- cricoid pressure occluding tip of ETT
- sudden, severe hypotension
Which type of heart block require cardiac pacing?
Second Degree (Mobiitz) Type 2
Third Degree
What is the most sensitive lead to diagnose ischemia?
V5
Next most sensitive is V4
What is the most sensitive lead to diagnose arrhythmia?
Lead II
ASA recommendations for pre-operative EKG
- Age greater than 50 y/o
a. Good for 1 year if age 50-69
b. Good for 6 months if >69 y/o - H/o CV disease or HTN
a. EKG only good for 6 weeks in pt w/ severe CV disease
b. EKG mandatory if patient has chance in symptoms: SOB, chest pain - H/o DM
a. EKG required if pt > 40 y/o
b. EKG required if pt has DM > 10 years - Central nervous system disease
Indications for Arterial Line
- Continuous, real time blood pressure monitoring
- Planned pharmacologic or mechanical cardiovascular manipulation
- Repeated blood sampling
a. ABG
b. Hematocrit
c. Glucose - Failure of indirect arterial blood pressure measurement
- Supplementary diagnostic information from the arterial waveform
a. Systolic pressure variation
b. Pule Pressure Variation (PPV) - Patient with end organ disease
- Patent with large fluid shifts
Complications of Arterial Line
- Distal ischemia 2/2 thrombosis, proximal emboli, or prolonged shock
- Pseudoaneurysm
- Arteriovenous fistula
- Hemorrhage
- Hematoma
- Infection
- Skin necrosis
- Peripheral neuropathy and damage to adjacent nerves
- Misinterpretation of data
- Cerebral air embolism 2/2 retrograde flow with flushing
Indications for a Central Line
- CVP Monitoring
- Transvenous cardiac pacing
- Required for insertion of PA catheter
- Temporary hemodialysis
- Drug administration: drugs that are irritating to peripheral veins
a. Vasoactive drugs
b. Hyperalimentation
c. Chemotherapy
d. Prolonged antibiotic therapy - Rapid infusion of fluids: trauma, major surgery
- Major surgery w/ large fluid shifts
- Aspiration of a venous air embolus
- Inadequate peripheral access
- Sampling site for repeater blood testing
Complications of Central Venous Line
- Mechanical injury: arterial, venous, nerve injury and cardiac tamponade
- Respiratory compromise: airway compression by a hematoma or PTX
- Arrhythmias
- Thromboembolic events: venous or arterial thrombosis, PE, and catheter/guidewire embolus
- Infectious: infection at site, catheter infection, blood stream infection, and endocarditis
- Misinterpretation of data
CVP Waveform components
a wave: end diastole; atrial contraction
c wave: early systole; isovolumetric ventricular contraction tricuspid motion toward right atrium
v wave: late systole; systolic filling of atrium
x descent: midsystole; atrial relaxation, descent of the base, systolic collapse
y descent: early diastole; early ventricular filling, diastolic collapse
Loss of a wave on CVP
A Fib/Flutter
Cannon a wave
-Right ventricular hypertrophy
-Tricuspid/Pulmonary stenosis
-Acute or chronic lung disease associated with pHTN
junctional or nodal rhythm
Large v wave
Tricuspid Regurgitation
Right ventricular papillary muscle ischemia
Indications. for PA catheter
- Cardiac
a. CHF
b. Low EF
c. Left sided, valvular heart disease
d. CABG
e. Aortic cross clamp - Pulmonary
a. COPD
b. ARDS - Complex fluid management
a. Shock
b. Burns
c. Acute renal failure - High risk obstetrical care
a. Ecclampsia
b. Placental abruption - Neurological
a. Sitting crani
b. Venous air embolus
Complications of PA catheter
- Venous access and PAC placement
a. Arterial puncture
b. Arrhythmias
i. RBBB
ii. Complete Heart Block
iii. V-Fib/tachycardia
c. Postoperative neuropathy
d. Pneumothorax
e. Air embolism - Catheter residence
a. Catheter knots
b. Infection
c. Thrombophlebitis
d. Thromboembolism
e. Pulmonary infarct
f. Endocarditis
g. Valvular injury
h. Pulmonary artery rupture
i. Pulmonary artery pseudoaneurysm - Death
- Misinterpretation of data
Causes of false INCREASE in Thermodilution CO reading
- Small injectate volume
- Increase temperature of inject ate
- Thrombus on thermister
- The patient is in a very low CO state
Causes of false DECREASE in Thermodilution CO reading
- Large injectate volume
- Decrease temperature of inject ate
- Inflation cycle of lower limb sequential compression devices (SCDs)
- Either rapid or continuous infusion of IV fluid through PA catheter 2/2 cooling effect on blood
RELATIVE Contraindications for TEE
- Paraesophageal hernia
- Cervical spine instability
- Atlantooccipital Disease or Instability
- Dysphagia
- History of esophageal or UGI bleeding
- Esophageal scarring from radiation
- Esophageal surgery
- Hiatal hernia
ABSOLUTE Contraindications for TEE
- Esophageal perforation
- Esophageal strictures
- Esophageal varacies
- Esophageal diverticula
How does PEEP work?
Recruits atelectatic, fluid-filled alveoli, decreasing intrapulmonary shunting and possibly increasing compliance
What is MAC?
Spinal nociceptive reflex involving both sensory and motor components
What is a dibucaine number?
The percentage that dibucaine inhibits the hydrolysis of benzoylcholine by pseudocholinesterase
What are the adverse effects of hypothermia?
- Shivering-induced increase in O1 consumption by as much as 400%
- Leftward shif of oxygen-hemoglobin dissociation curve
- Decreased blood clotting ability (10% reduction of coagulation factor activity for every 1 degree Celsius decrease)
- Increased epinephrine and norepinephrine levels causing vasoconstriction
- Cardiac arrhythmias progressing to V Fib
