AP 3 Final LAST ONE!!!!!!!!! Flashcards
What does “gravida” mean?
Number of times a patient has been pregnant
What does “parity” mean?
Number of babies born
What do the 4 numbers listed under “parity” on a patient’s chart mean?
- Full term births
- Preterm births
- Losses (spontaneous or otherwise)
- Living children
What is a baby considered “full term” when calculating gestational age?
Full term starts at 38 weeks gestation
A woman’s blood volume increases by __% during pregnancy
40
A woman’s heart rate increases by __% during pregnancy
15-20
A woman’s stroke volume increases by __% during pregnancy
25%
A woman’s cardiac output increases by __% during pregnancy
50%
How is a woman’s arterial pressure affected by pregnancy? Why?
Decreases by up to 15% due to decrease in peripheral vascular resistance
How much does a woman’s cardiac output increase immediately after delivery?
As much as 80% (12-14L/min)
What EKG changes can be seen in the pregnant woman? Why?
Left axis deviation due to the displacement of diaphragm by uterus
What is aortocaval compression (aka supine hypotensive syndrome)?
When a pregnant women is supine, the uterus causes…
-Aortoiliac compression in 15-20% of women
-Compression of the inferior vena cava in ALL women.
This causes decreased venous return to the heart, leading to hypotension.
What is the solution for aortocaval compression?
Left uterine displacement - elevate the right hip to roll the uterus off the vena cava
How does minute ventilation change in a pregnant woman?
Increases due to increased RR and TV
How does the position of the diaphragm in a pregnant woman affect lung volumes?
The diaphragm is pushed more cephalad, which causes a decrease in FRC
How does a decrease in the FRC of pregnant women affect induction of general anesthesia?
They have less oxygen in their lungs and it gets used more rapidly, thus they desaturate much more quickly
How does the airway change during pregnancy?
Capillary engorgement of the mucosa causes swelling and difficult DL views
What airway management techniques should be avoided in pregnant women?
Nasal instrumentation due to swollen and friable tissue
What pregnancy condition can cause the airway to worsen quickly over a couple hours?
Pre-eclampsia
Most common cause of anesthesia-related mortality in pregnant patients
Loss of airway
Major GI changes in pregnant women (3)
- Delayed stomach emptying (due to uterus displacing stomach)
- GERD (due to GE junction loosening)
- Stomach contents are more acidic (placenta secretes gastrin)
Due to the GI changes of pregnant women, all of these patients are treated as…
Full stomach
GI changes of pregnant women cause them to be at significant risk of…
Aspiration
What should you consider when picking ETT sizes for pregnant women
Pick slightly smaller size due to airway swelling
Due to their GI changes, what medication should pregnant women take before surgery
Sodium citrate (bicitra) - makes stomach contents less acidic
What hematologic condition is common during pregnancy?
Anemia
Why are pregnant women prone to anemia?
Plasma volume increases by 40% and red cell mass increases by 20%, so there is a slightly reduced red cell concentration in the blood
Normal Hgb levels for pregnant patients
11-12g/dL
Normal Hct for pregnant patients
35%
How does platelet count change in a pregnant woman
Decreases
How does clotting change during pregnancy? Why?
Pregnancy is a “hyper-coagulable state”. There is an increase in coagulation factors and also anti-clotting activity, so there is increased clot formation and clot breakdown.
Since pregnancy is a “hypercoagulable state” - pregnant woman are more at risk for…
DVT
Oxygen consumption increases by __% in pregnant women
20%
How does PaCO2 change in pregnant women
Decreases
How does pH change in pregnant women
Unchanged
How do placental hormones affect the mother’s glucose levels
Can lead to hyperglycemia, can cause gestational diabetes
How does plasma cholinesterase levels change in pregnant women
Decreases - but not enough to affect succinylcholine clearance
How do plasma protein concentrations change in pregnant women
Decrease via dilution
How long after conception does there begin to be a decrease in MAC levels for the pregnant patient?
8-12 weeks after gestation
How does the spread of neuraxial medications change during pregnancy?
Increases
Number one cause of pregnancy-related mortality worldwide
Hemorrhage
Number one cause of pregnancy-related mortality in the US
Cardiovascular disease
Anesthesia related maternal mortality is the __th leading cause of maternal mortality
10th
Causes of anesthesia-related maternal mortality
Failure to secure the airway is the top cause…others include
- pulmonary aspiration
- high spinal
- LAST due to IV injection of local
Safest and most effective medical intervention for labor pain
Lumbar epidural
Can opioids be given for labor pain?
Yes - they can be a risk for the baby and mother and not as effective as epidurals, but possibly the best option if epidural isnt possible
When is a patient in “labor”
When they are having uterine contractions that result in a cervical change
What is stage 1 of labor
Dilation of cervix to 10cm
Stage 1 of labor is broken down into what 3 phases
- Latent labor
- Active labor (accelerated cervical change that beings at 4-6cm)
- Transition into stage 2 of labor
Where does the pain from stage 1 of labor originate?
Visceral pain from uterus and cervix, innervated by T10-L1
Stage 2 of labor
Fetus passing through cervix and into vaginal canal
Where does the pain from stage 2 of labor originate?
Somatic pain from compression of perineal tissue, innervated by S2-S4
Stage 3 of labor
Delivery of the placenta
Sudden, severe pain during stage 3 of labor should cause concern for…
Uterine inversion
What is the Puerperal period of labor (stage 4)?
From after delivery of the placenta until return to non-pregnant physiology (usually 2-6 weeks after delivery)
Contraindications to neuraxial block
1) Patient refusal
2) Thrombocytopenia
3) Coagulopathy/recent use of anticoagulants
4) Infection at site of needle placement
5) Untreated intravascular bacteremia/viremia
6) Foreign bodies/hardware in back
7) Certain pathologies of spinal cord (spina bifida)
There is a contraindication to a neuraxial block during what phase of labor
Complete dilation of the cervix during the 2nd stage of labor
Most painful stage of labor
2
When is an epidural for delivery normally placed?
After active labor has begun - can be placed any time after a patient is committed to labor
What can help prevent hypotension from epidural placement
Fluid bolus before or during placement
Patient history needed before placing an epidural for delivery
- Age
- Gravida
- Parity
- Gestation
- Medical problems
- Cervical exam
Physical exam needed before epidural placement for delivery
- Vital signs (including temp)
- Height
- Weight
- Airway
Labs needed before epidural placement for delivery
- Platelet #
- Hgb/hct
- White count
What monitors are necessary to have on patient during epidural placement
- Pulse ox
- BP every 5 minutes
What gauge are epidural needles used for delivery
17 or 18 gauge
Why is extra care and precision needed when assessing loss of resistance during epidural placement for a delivery
The ligaments are softer in pregnant women so loss of resistance can be more subtle
A test dose for an epidural tells us what?
If the epidural is in the intrathecal or intravascular space
Classic test dose for epidurals
3mls of Lidocaine 1.5% and 1:200,000 epi
Signs that an epidural catheter is intrathecal
- Warmth in bottom
- Numbness
- Difficulty moving legs
Signs that an epidural catheter is intravascular
- Ringing in ears
- Numbness around mouth
- Metallic taste
- Increased HR within 30 seconds (usually to ~130bpm)
When dosing an epidural, what amount of local is incrementally injected?
3 or 5mL boluses
What local anesthetic is usually used for an epidural for delivery
Long acting agent such as bupivicaine or ropivicaine
Tools used to assess which dermatomes are blocked to pain after an epidural placement
- Pinprick
- Alcohol swabs
- Ice
What is a CSE?
Combined spinal epidural - once the epidural space is found, a spinal needle is inserted through the epidural catheter and medications are injected (usually fentanyl or low dose local)
Benefits of CSE
- Near-immediate pain relief
- Confirmation of epidural space
Risks of CSE
- Spinal headache
- Paresthesias
What is a subdural catheter?
When the epidural catheter ends up between the dura and the arachnoid
Risks of epidural placement
- Inadvertent dural puncture
- Hypotension (can affect fetus)
- Failed block
- IV/intrathecal injection
- Nerve injury
- Prolongation of stage 2 of labor
- Epidural hematoma
- Infection
What is an inadvertent dural puncture?
Also called a “wet tap” - when the epidural needle punctures the dura and CSF comes through
A wet tap dramatically increases the risk of…
Postdural puncture headache due to continual leakage of CSF
Definitive treatment for inadvertent dural puncture
Blood patch - epidural injection of blood
What treatments for inadvertent dural puncture should be tried first?
- Lying flat
- Caffeine
- Pain pills
Complications of blood patch
- Shooting pains in legs
- Infection
- New wet tap
What is done by the practitioner in the event of a wet tap?
Either…
1) The needle is removed and epidural placed at an adjacent level
2) Catheter is inserted into the intrathecal space
Indications for C-section
- Arrest of dilation
- Nonreassuring fetal heart rate
- Cephalopelvic disproportion
- Prior c-section
- Malpresentation
- Prior surgery involved uterine corpus
- Arrest of descent
- Uterine cord prolapse
- Placental abruption
Normal fetal heart rate
110-160bpm
Early decelerations in fetal heart rate during a contraction is often associated with…
Head compression as fetus moves toward delivery
Variable decelerations in fetal heart rate during a contraction can be associated with…
Uterine cord prolapse
Late decelerations in fetal heart rate during a contraction are suggestive of…
Fetal asphyxia during contractions
Anesthetic options available for c-section
Epidural, spinal, or general
What are neuraxial considerations for c-section?
- Need T4 block to block peritoneal stimulation
- Need denser block than for labor
Mortality rates in c-sections are __ times greater with general than neuraxial anesthesia
17
Fetal transfer of general anesthesia induction drugs are all but inevitable if the delivery is delayed more than __ minutes after induction
2
What induction drugs are not transferred to fetus
Paralytics
What is a single spot spinal
A small gauge needle is inserted into subarachnoid space and meds are injected
Benefits of single shot spinal
Quick with no risk of large gauge dural punction
Risks of single shot spinal
- High block
- Hypotension
Single shot spinals are contraindicated in pregnant patients with what disease
Multiple sclerosis
What local anesthetics are used in epidurals for a C-section
More concentrated locals…
- Bupivicaine 0.5%
- Lidocaine 2%
- Chloroprocaine 3%
Effects of morphine in a spinal or epidural
Gives 24 hour improved pain control but delayed risk of respiratory depression
Monitors needed for c-section
- ASA
- Fetal heart tones must be assessed and monitored after anesthesia is induced
First sign of hypotension in patient undergoing c-section under regional anesthesia
Nausea/vomiting
Reflexing the table so the uterus is at the bottom of the patient reduces the risk of…
Venous air embolism
What medication is given immediately after the baby is born in a c-section
Pitocin - reduces uterine atony and hemorrhage
Pain med considerations for the mother once the baby is delivered in a c-section
Epidural opiods are given. Can safely give more sedatives, narcs, etc since there is no longer a fear of fetal transfer
Anesthetic options for emergency c-section
- If epidural is functioning and in place, dose it up
- If not, choose general or lateral spinal
Preparations necessary if a general anesthetic is chosen for an emergency c-section
Patient must be prepped and draped prior to induction of general anesthesia so that if induction goes badly, the fetus can be saved
Induction plan for emergency c-section
RSI with propofol and succinylcholine
How must volatile anesthetics be managed after the baby is delivered in a c-section?
Use MINIMAL volatile because volatile agents relax the uterus and contribute to uterine atony
In general, the patient feels more sensation during a c-section with what neuraxial method?
Epidural
When should you consider re-dosing catheter during c-section
1-1.5 hr after surgery start
If a single shot spinal wears off during c-section, what can be given for powerful pain management that will still preserve ventilation
Ketamine
Premature labor is labor that occurs between…
20 and 37 weeks gestation
Contributing factors to premature labor
- Extremes of age
- Inappropriate prenatal care
- Increased physical activity
- Unusual body habitus
- Previous preterm delivery
- Multiple pregnancies
- Infection
Fetal complications of premature labor
- Hypoxemia/asphyxia from umbilical cord compression
- Inadequate surfactant levels
- Intracranial hemorrhage due to poorly calcified cranium
When are surfactant levels adequate in fetuses
After 35 weeks
What is premature rupture of membranes (PROM)?
Leakage of amniotic fluid that occurs before the onset of labor
Predisposing factors for PROM
- Short cervix
- History of preterm labor
- Infection
- Multiple gestations
- Polyhydramnios
- Smoking
If PROM occurs, delivery is indicated if the the fetus is over __ weeks gestation
34
What is done if PROM occurs and the fetus is less than 34 weeks
Give prophylactic antibiotics and tocolytics to prevent labor for 5-7 days
Maternal complications from chorioamniotitis
- Dysfunctional labor
- Intraabdominal infection
- Septicemia
- Postpartum hemorrhage
Fetal complications from chorioamniotitis
- Premature labor
- Acidosis
- Hypoxia
- Septicemia
Clinical signs of chorioamniotitis
- Fever over 38C
- Maternal and fetal tachycardia
- Uterine tenderness
- Foul smelling/purulent amniotic fluid
Predisposing factors to uterine cord prolapse
- Excessive cord length
- Malpresentation
- Low birth weight
- Grand parity (over 5 births)
- Multiple gestations
- Artificial rupture of membranes
Diagnosis of uterine cord prolapse
- Sudden fetal bradycardia
- Profound decelerations
Treatment of uterine cord prolapse
- Immediate steep trendelburg or knees to chest
- Pushing of fetal part back into pelvis
Anesthetic method for uterine cord prolapse
General anesthesia for the c-section
Classic triad of signs of an amniotic fluid embolism
- Acute hypoxemia
- Hemodynamic collapse - severe hypotension
- Coagulopathy without obvious cause
Other s/s of amniotic fluid embolism
- Pulmonary edema
- Cyanosis
- CV arrest
- DIC
- Fetal distress
- Seizures
3 main pathophysiological manifestations of amniotic fluid embolism
- Acute pulmonary embolism
- DIC
- Uterine atony
Treatment for amniotic fluid embolism
- Aggressive CPR and supportive care
- Immediate c section
WHICH OF THE FOLLOWING SIGNS & SYMPTOMS IS NOT ASSOCIATED WITH AMNIOTIC FLUID EMBOLISM?
A. CARDIOPULMONARY ARREST B. HYPERTENSION C. BLEEDING (DIC) D. PULMONARY EDEMA OR ACUTE RESPIRATORY DISTRESS SYNDROME (ARDS) E. SEIZURES
B. Hypertension
AN EPIDURAL IS PLACED INTO 32 YR OLD PARTURIENT RECEIVING MAGNESIUM THERAPY FOR PREECLAMPSIA. FIVE MINUTES AFTER ADMINSTRATION OF THE TEST DOSE, THE BOLUS INFUSION IS INTERRUPTED BECAUSE OF A CONTRACTION. AFTER THE CTX SUBSIDES, A SLOW EPIDURAL INJECTION OF THE LOADING DOSE OF BUPIVACAINE & FENTANYL IS RESUMED. AT THE SAME TIME, THE PATIENT COMPLAINS OF SHORTNESS OF BREATH. SHE IS PANIC-STRICKEN & WRESTLES VIOLENTLY WITH THE NURSES WHO ARE TRYING TO REASSURE HER. SHE REPEATS THAT SHE CANNOT BREATHE, BECOMES CYANOTIC, & LOSES CONSCIOUSNESS. DURING RESUSCITATION, BLOOD IS OOZING FROM THE IV SITES & PINK FROTH IS NOTED IN THE ENDOTRACHEAL TUBE.
THE MOST LIKELY DIAGNOSIS IS:
A. AMNIOTIC FLUID EMBOLISM B. HIGH SPINAL C. INTRAVASCULAR BUPIVACAINE INJECTION D. MAGNESIUM OVERDOSE E. ECLAMPSIA
A. Amniotic fluid embolism
What is placenta previa
When the placenta covers the internal cervical opening
Risk factors for placenta previa
- Scarring of uterine wall by previous pregnancies, surgeries, abortions, etc.
- Multiple pregnancy (twins, triplets, etc)
- Many previous pregnancies
- Abnormally developed uterus
Symptoms of placenta previa
- Painless vaginal bleeding
- Episodic bleeding
Until proven otherwise, all pregnant patients with vaginal bleeding are assumed to have…
Placenta previa
Anesthetic management for placenta previa of an unstable patient
General anesthesia
- 2 large bore IVs
- Vigorous volume replacement
- Crossmatch 2 units
- Central line good for rapid transfusion and monitoring
A 30 YR OLD PRIMIPAROUS PATIENT WITH PLACENTA PREVIA & ACTIVE VAGINAL BLEEDING ARRIVES IN THE OPERATING ROOM WITH A SYSTOLIC BP OF 85 MM HG. A CESAREAN SECTION IS PLANNED. THE PATIENT IS LIGHTHEADED & SCARED.
WHICH OF THE FOLLOWING ANESTHETIC INDUCTION PLANS WOULD BE MOST APPROPRIATE FOR THIS PATIENT?
A) SPINAL ANESTHETIC WITH 12 TO 15 MG OF BUPIVACAINE
B) EPIDURAL ANESTHETIC WITH 20-25 ML 3% 2-CHLOROPROCAINE
C) GA INDUCTION W/ 3-4 MG/KG THIOPENTHAL, INTUBATING WITH 1-1.5 MG/KG SUCCINYLCHOLINE
D) GA INDUCTION W/ 0.5 MG/KG KETAMINE, INTUBATION W/ 1-1.5 MG/KG SUCCINYLCHOLINE
E) REPLACE LOST BLOOD VOLUME FIRST, THEN USE ANY ANESTHETIC THE PATIENT WISHES
D) GA INDUCTION W/ 0.5 MG/KG KETAMINE, INTUBATION W/ 1-1.5 MG/KG SUCCINYLCHOLINE
Causes of antepartum hemorrhages
1) Placenta previa
2) Placental abruption
What is placental abruption
Separation of normal placenta after 20 weeks of gestation causing fetal distress
Most common cause of intrapartum fetal death
Placental abruption
Risk factors for placental abruption
- HTN
- Trauma
- Short umbilical cord
- Multiparity
- Prolonged PROM
- Tobacco use
- ETOH abuse
- Cocaine use
Symptoms of placental abruption
- Painful vaginal bleeding
- HTN
- DIC
- Uterine tenderness
- Increased uterine activity
Diagnosis of placental abruption
- U/s to exclude placenta previa
- Amniotic fluid is port wine colored
With mild to moderate placental abruption, fibrinogen levels are reduced to…
150-250 mg/dL (normal 200-500)
With severe placental abruption, fibrinogen levels are reduced to…
Below 150
Anesthetic management of placental abruption
- Fetal heart rate monitoring
- Large gauge IVs
- Aggressive volume resuscitation
- Check HCT and coagulation
- Type and cross units
If a pregnant patient is unstable and needs blood but you don’t know her blood type, what type should you give?
O negative
Cause of peripartum hemorrhage
Uterine rupture
S/s of uterine rupture
- Constant pain
- Hypotension
- Fetal distress
- Ineffective contractions
Most reliable sign of uterine rupture
Fetal distress
Treatment for uterine rupture
Volume resuscitation and immediate laparotomy under general anesthesia
Even with epidural anesthesia, uterine rupture often presents as…
Abrupt onset of continuous abdominal pain with hypotension
What is a retained placenta
When fragments of placenta are still attach to uterus after delivery and cause the open blood vessels on the uterus to continue to bleed
Causes of postpartum hemorrhages
1) Placenta accreta
2) Uterine atony
What is placenta accreta
Abnormally adherent placenta
The majority of cases of placenta accreta are of what type?
Placenta accreta vera - adherence to myometrium without invasion through uterine muscle
Risk factors for placenta accreta
- History of placenta previa
- Previous c section
WHICH OF THE FOLLOWING PATIENTS IS MOST LIKELY TO NEED AN EMERGENCY HYSTERECTOMY FOR UNCONTROLLED BLEEDING AT THE TIME OF DELIVERY?
A) PATIENT WITH PLACENTA ABRUPTION
B) PATIENT UNDERGOING A VAGINAL BIRTH AFTER CESAREAN SECTION
C) PATIENT WITH QUADRUPLETS
D) PATIENT WITH A PLACENTA PREVIA (NOT BLEEDING) FOR AN ELECTIVE REPEAT CESAREAN SECTION
E) PATIENT WITH AN ABDOMINAL PREGNANCY
D. PATIENT WITH A PLACENTA PREVIA (NOT BLEEDING) FOR AN ELECTIVE REPEAT CESAREAN SECTION (PREVIA & PREVIOUS SCAR OF THE UTERUS HIGH CHANCE OF PLACENTA ACCRETA)
Treatment for uterine atony
- Oxytocin
- Methergine
- Prostaglandin F2-alpha (Hemabate)
MOA of oxytocin in uterus
Stimulates frequency and force of contraction
MOA of oxytocin in mammary glands
Stimulates contraction of cells to force milk into large sinuses
MOA of oxytocin in cardiovascular system
Causes vasodilation, decreased BP, flushing, reflex tachy, increase in limb blood flow
Postpartum dose of oxytocin
20 units in 1000mL LR
Infusion rate of oxytocin
20-40mU/minute
Onset of IV oxytocin
1 min
Duration of IV oxytocin
30 min
Side effects of oxytocin
- Hypotension
- N/V
MOA of methergine
Acts directly on smooth muscle of uterus via alpha receptors to increase tone, rate, amplitude of uterine contractions
Dosing for methergine
- 0.2 mg IM
- 0.02 mg IV every 5 min
Onset of IV methergine
Immediate
Duration of IV methergine
45 min
Use methergine cautiously in patients with…
- Pre-eclampsia
- HTN
- Asthma
- Cardiac disease
MOA of prostaglandin F2alpha (hemabate)
Stimulates smooth muscle and uterine contractions
Dosage and route of PF2a
250mcg IM
Max dose of PF2a
2mg
Onset of PF2a
Less than 5 min
Duration of PF2a
Over an hour
Contraindications for PF2a
Asthmatics