Obstetric Airway Management Flashcards
What are the two major reasons that airway is a leading cause of anesthetic mortality
1) to secure a patient airway
2) Aspiration
Anesthesia related obstetric mortality occurs in how many patients
1: 500,000 Pregnancies
What are the risk associated with pregnancy and airways
1) Failure to Intubate
2) Aspiration
3) Hypoxemia
4) Urgency for two patients
5) Failure to prepare completely, I.e. plan A, B,C …
True or false. NPO status eliminates risk of aspiration
False. It does not eliminate risk for aspiration
In regards to aspiration what decreases gastric emptying? Increases gastric acidity?
Decreased gastric emptying
1) Progesterone
2) Stress of labor
3) Narcotics
Increase gastric acidity
1) Gastrin
What factors decrease gastric emptying
1) Progesterone
2) stress of labor
3) narcotics
What causes increases in gastric acid
Gastrin
What causes decreased Gastro esophageal sphincter tone
1) Reflux patients
2) anticholinergics ( Impede tone)
3) narcotics
4) insertion and removal of NG tube (impacts competency of GE Junction)
How does pregnancy effect gastric pressures
Single pregnancy, 7 –> 17 cmH2O
Twin pregnancy, 7 –> 40
How does the lithotomy position Impact gastric Pressure
Single pregnancy, 17 –> 24 cmH2O
What factors contribute to failure to Intubate
1) Upper airway edema
2) adiposity of Head, neck, and trunk
3) breast enlargement
In comparison to non-gravid patients what is the failure to Intubate rate
10 fold. ( Actual number 1: 250)
What are the contributing factors to hypoxemia during pregnancy
FRC decreases by 20% in pregnancy
VO2 (Oxygen consumption)
Increases by 20% in term
Increases by 60% in active labor
In regards to your pre-op consult, how do you Identify the increased risks
1) Perform excellent airway history exam
2) asses head neck trunk breast when supine 3) assess ability to visualize upper airway
4) documented history exam and increase risk and discuss with patient family
What are some causes of aspiration in the Obstetric patient
1) Decreased gastric emptying
2) Increased gastric acidity
3) Decreased gastroesophageal sphincter tone
4) Hiatal hernia (27%)
5) Increased gastric pressure
6) Failure to Intubate
What causes of decreased gastric Emptying
1) Progesterone
2) Stress of labor
3) narcotics
What are causes of increased gastric acidity
Gastrin
Water causes of decreased gastroesophageal sphincter tone
1) Reflux patients
2) anitcholinergics (Impede tone)
3) narcotics
4) insertion and removal of NG tube (Effect competency of GE junction)
How does pregnancy affect gastric pressures
Single fetus = 7 –> 17 cmH2O
Twin fetus = 7 –> 40
Lithotomy position impacts gastric pressure by increasing from 17 –> 40 cmH2O in single status (Obviously more in multiple fetus)
What are contributing factors for failure Intubate
1) Upper airway edema
2) adiposity of head and neck and trunk
3) breast enlargement
How does the gravid patient impact the rate of failure to Intubate
A 10 fold increase
Actual number: 1 in 250 failed
What are the contributing factors to Hypoxemia during pregnant
FRC is decreased by 20%
V O2 (Oxygen consumption)
Increased by 20% in term
Increased by 60% in active labor
In regards to anesthetic management how we manage the increased risk of The pregnant patient
1) Identify the risk
2) prevent acid reflux
3) identify single or multiple gestation
4) vigilant during Active labor
What should the preop evaluation consistent of for the pregnant patient
1) Perform excellent airway history And exam
2) Assess head neck trunk breast when supine
3) assess ability to visualize upper airway
4) document the history exam and increase risk also discussed with patient and family
In regards to aspiration prophylaxis what should be given preop
1) IV fluids
2) cimetidine 300 mg IV 60 minutes prior (H2 blocker - to inhibit gastric acid secretion
3) metoclopramide 10 mg IV 30 minutes prior (To increase gastric emptying)
4) sodium citrate 30 mL PO immediately prior (To increase pH, Neutralize gastric contents)
In preparing plan A for the obstetric patient what are our goals
Prepare for first attempt success by:
1) Optimize patient positioning
2) provide complete the oxygenation
3) downsize ETT
4) utilize Sellick maneuver throughout
5) utilized ETT introducer if needed
6) move to plan B at predetermined endpoint
remember fetus is desaturating just like mom
Ok… so what if you did have to move to plan B, what would you be doing?
1) Main goal is to oxygenate both patients
2) Continue Sellick maneuver
3) ventilate the patient
What you had to go to plan C? then what?
Utilize HPOV v/s RGW. (For details see difficult airway cards)
