Class 3 Surgery Flashcards
Indications for C-section
- Failure to progress
- Fetal distress
- Fetal malpresentation
- Previous C/S or failed VBAC
- fetal/maternal condition making vag delivery unsafe
What is the most common analgesia technique for C/S and why?
- Regional
- Safer than GA
- Epidural already in place
- Less neonatal depression
- Mother is awake
Reasons for GA for C/S
- Fetal distress with no time for block
- Non functioning epidural
- Any block contraindications
- Regional inadequate
- Patient refusal
Disadvantages of GA for C/S
- Not as safe as regional
- Difficult airways
- Failed intubation
- Failed ventilation
- Awareness
- Aspiration pneumonia
What is the optimal time between uterine incision and delivery?
-3 minutes
Infants exposed to GA have ______ Apgar at one minute but __________ at 5 mins.
- Lower
- No difference
Aspirations prophylaxis in C/S.
- Antacid (sodium bicitrate) = Raise pH
- Ranitidine (zantac) = H2 blocker
- Metoclopramide (Reglan) = Decrease gastric volume
A combination of what two things results in faster desaturation among C/S? Which makes what critically important and how should it be done?
- Increased O2 consumption and decrease FRC
- Preoxygenation
- 100% O2 w/ tight mask for at least 3 minutes
Propofol dose and tidbit?
- 2.0-2.8 mg/kg
- Readily crosses placenta
Ketamine dose and tidbits?
- 1.0-1.5
- Useful for hemorrhage (BP support)
- Decrease bronchospasm
- Sfx = HTN and Dysphoria
Versed problems
-Neonatal depression
Etomidate problem
-Neonate adrenal supression
What type of induction is mandatory in most C/S?
-Rapid sequence
Why are muscle relaxants safe in OB?
-Hydrophilic nature limits placenta transfer
2 options for GA maintenance?
- 50% nitrous + 2/3 MAC of volatile agent
- 1.2 MAC + Fentanyl until delivery, then 0.5 MAC + N2O +Versed
In most prospective studies the incidence of neonatal depression is _______ between general and regional anesthesia.
-Similar
Epidural advantages in C/S
- Tailored doses
- Can prolong block for long case
- Post op analgesia
- Gradual block w/ less hemodynamic change
Disadvantages in epidurals for C/S
- Patient contrainndications
- Not as good as spinal
- May not produce enough surgical block w/ ten fold increase in total spinal risk
How does an epidural work?
- LA infuses into epidural nerve roots
- Sodium channels are blocked
- Sensory and motor function is reduced
A midthoracic block height results in what?
- Lower extremity sympathectomy and splanchnic beds
- Decreases venous return and BP
- Arterial dilation
What happens if block reaches to T1?
-Decrease in HR and contractility
What happens with a sensory block above T2?
-Sense of dyspnea
With an epidural, how are expiratory pressure and flows reduced?
-In proportion with decreased abd muscle strength
What will speed onset of lidocaine of 2-chloprocaine?
-Bicarb
What is the ideal block height for epidural?
-T4-T8
How to treat breakthrough pain?
- 5cc epidural local
- Fentanyl IV or epidural
- N2O
- Ketamine
- Surgeon to infiltrate w/ local
- Convert to GA if not working
Why is spinal better than epidural?
- More dense block w/ single injection
- Defined end point (CSF=correct place)
- No IV injection concerns
- Faster and more simple than placing catheter
Disadvantages of spinal vs. epidural
- Finite duration
- PDPH
- Total spinal
- Maternal hypotension
Why do laboring women have less hypotension than non-laboring women?
- Laboring women have been in the hospital and have received fluids
- Aortocaval depression is reduced by head into pelvis
Reason why phenylepherine is now the drug of choice for hypotension in OB.
- phenylepherine uterine vasoconstriction have not been proven
- Ephedrine increases fetal acidosis
Tetracaine considerations
- Long time to work
- Long duration
- unreliable
Lidocaine considerations
- Short acting
- Neurological symptoms
Bupivicaine considerations
- Best choice
- quick onset
- Intermediate duration
Duramorph considerations
- Long acting analgesia
- Delayed respiratory depression
- Nausea
- Pruritis
Once in the OR and block is in what position should the patient be placed?
-Lateral tilt
After delivery, what should be given?
- 20 units of pitocin in 1L bag
- Consider duramorph
Most common non obstetric surgeries in preggos?
- Appendix
- Gallbladder
Preggo altered response to anesthesia.
- Decrease MAC
- Increase sensitivity to Neuraxial agents
- Decrease plasma cholinesterase
- Decreased protein binding
What anesthesia meds are deemed safe for fetus?
- Thiopental
- Morphine
- Meperdine
- Fentanyl
- Muscle relaxants
Anesthetic management for preggos
- Avoid: hypoxemia, hypotension, acidosis
- Maintain PaCO2 in normal range
- Minimize aortacaval compression effects
What should be monitored at 20 weeks?
- Fetal HR
- Uterine activity
If organized uterine activity is detected, what can be used?
- Beta agonist like ritodrine
- Magnesium
What drugs need t be avoided with preggos?
- Benzos (congential anomalies)
- Nitrous (Interfere with B12)
When should elective surgery be scheduled after delivery?
-6 weeks after
When are physiological effects of pregnancy well established?
20 weeks
Volatile agents may suppress what?
Preterm labor
