Book 4, Case 4 OB and Ischemic Cardiomyopathy Flashcards
What do you want to know about OB patients -period, in addition to their stuff?
How’s the baby? What’s the obstetric plan?
EKG changes that can be normal (even though there are some pathologies)
However, I would keep in mind that the ECG of a normal healthy pregnant
patient may exhibit abnormalities like left axis deviation, ST-segment depression, and
a Q-wave in lead III.
Would you recommend a cesarean section for this patient?
I would not recommend a cesarean section simply because of her
cardiac condition because, although a cesarean section has the advantage of avoiding
the prolonged stress of labor and the profound hyperdynamic circulatory changes that
occur at delivery, it still involves a significant amount of cardiovascular stress
(cardiac output increases by up to 50% during cesarean section) and, moreover, is
associated with increased blood loss, a higher risk of infection, delayed ambulation,
and increased postoperative pain.
However, this patient’s high blood pressure and urinary protein suggest she may be
preeclamptic, in which case, a cesarean section may be indicated should her condition
become severe (i.e. headache, visual disturbances, epigastric pain, HELLP,
intrauterine growth restriction, oliguria, pulmonary edema, BP 2: 160/110 mmHg,
proteinuria > 5 g/24 hr) or should she become eclamptic.
Pt with hx of MI and Ischemic cardiomyopathy with PET: you giving Mg?
And then if it was determined that she had to have Mg-what are you going to watch for?
And what will you do if Mg toxicity is seen?
I would not recommend magnesium sulfate for this patient with
ischemic cardiomyopathy and a recent myocardial infarction. With this cardiac
history, magnesium administration would be relatively contraindicated due to the
deleterious cardiac effects that may occur with its use, such as hypotension,
bradycardia, complete heart block, and cardiac arrest. However, I recognize that
magnesium sulfate would be beneficial for seizure prophylaxis in the setting of severe
preeclampsia. Therefore, I would discuss the risks and benefits of magnesium
administration with both the obstetrician and the patient’s cardiologist.
If it were determined that prophylactic magnesium sulfate should be administered, I
would monitor the patient carefully for signs of toxicity such as: (1) loss of patellar
reflexes, (2) hypotension, (3) significant changes in mental status (CNS depression),
(4) respiratory depression, (5) prolonged PR interval, (6) widened QRS, and (7)
prolonged QT interval.
If the patient demonstrated any signs of toxicity, I would immediately: (1)
discontinue administration, (2) check a magnesium level, (3) administer a diuretic (to
increase renal excretion), and (4) give calcium gluconate to antagonize the neurologic
and cardiac effects of magnesium.
Risk of Mg toxicity increased with:
The risk of cardiotoxicity secondary hypermagnesemia is increased in the setting
of hypocalcemia, hyperkalemia, renal insufficiency, and digitalis therapy.
Go over Mg EKG changes
MEq/L 5-10: EKG changes 10: Muscle weakness, loss of DTRs 15: SA/AV node block 20: cardiac arrest
Plt count 74,000-you placing epidural? If so, what are you going to be watching for?
Assuming there were no signs of coagulopathy, I would still proceed
with neuraxial anesthesia due to my concern about the potential for difficult airway
management. However, I recognize that the risk for epidural hematoma is even
higher with a lower platelet value such as 74,000. Therefore, I would take specific
precautions to prevent hematoma-induced neurologic injury, such as delaying catheter
removal until lower extremity motor function had returned (this allows for subsequent
evaluation of motor function following catheter removal - a time of increased risk of
epidural bleeding) and, following catheter removal, performing hourly neurologic
examinations to ensure that the symptoms of spinal cord compression were quickly
identified to allow for timely treatment.
You are raising the epidural and no1l:ice ST-segment depression on the EKG.
What are you going to do?
I would cease any epidural injections, and attempt to optimize the
myocardial oxygen supply/demand relationship. To this end, I would continue
supplemental oxygenation, ensure adequate left uterine displacement, and treat any
tachycardia, hypotension, hypertension, and/or dysrhythmia. In the absence of
significant hypotension,
Pregnant woman codes, and is in asystole-wyd?
I would immediately: (1) call for help and a defibrillator (in case a
shockable rhythm developed during resuscitation). I would then (2) secure the
airway, (3) provide positive pressure ventilation with 100% oxygen, ( 4) ensure left
uterine displacement, and (5) start chest compressions. Next, I would attempt to (6)
confirm true asystole (make sure all cables are connected properly, ensure adequate
monitor gain, check another lead, check for pulse - very fine ventricular fibrillation
can look like asystole ), and (7) administer 1 mg of epinephrine intravenously.
would then (8) continue to monitor the patient for the development of a shockable
rhythm, (9) attempt to identify and treat the underlying cause of the arrest (which in
this case is most likely myocardial ischemia and/or infarction), and (10) give
additional 1 mg doses of epinephrine every 3-5 minutes until the patient moved out of
asystole or until resuscitative efforts were discontinued (one dose of vasopressin 40 U
can be substituted for the first or second dose of epinephrine). If she did not respond
to resuscitative efforts within the first few minutes, I would ask the obstetrician to
deliver the baby to improve the chances of survival for both the mother and her baby.
What is your differential for her cardiac arrest?
Given her recent myocardial infarction and cardiac history, the most
likely cause of cardiac arrest in this patient is (1) myocardial ischemia and/or
infarction secondary to coronary artery disease. However, other causes to be
considered would include (2) amniotic fluid embolism (she is at higher risk of
placental abruption since she is preeclamptic), (3) pulmonary embolism (she is atincreased risk of DVT secondary to the hypercoagulable state of pregnancy and the
inactivity likely associated with her obesity and extreme shortness of breath), (4)
rupture of a subcapsular hematoma (a known life-threatening complication of HELLP
syndrome), (5) intracranial hemorrhage (higher risk in severe preeclampsia), (6) local
anesthetic toxicity (her epidural block was being raised at the time of arrest), (7)
hypovolemia (severe preeclampsia), (8) hypokalemia (patient is taking a loop
diuretic), and (9) tension pneumothorax (if a central line was placed for the case).
Will you deliver the baby before starting cardiac compressions?
I would not deliver the baby before starting compressions because of
the importance of immediately starting compressions to provide minimal end-organ
perfusion and circulation of administered epinephrine or vasopressin. However, I
recognize that delivery of the baby within 5 minutes may improve the chances of
survival for both the mother and the infant by: 1) relieving aortocaval compression,
which improves venous return to the heart, 2) decreasing metabolic demands, and 3)
allowing for more effective chest compressions. Therefore, if resuscitative efforts
were not successful within the first couple of minutes, I would ask the obstetrician to
perform an immediate cesarean section.
The baby is delivered and you note that the patient now has a pulse, but is in
ventricular tachycardia. What will you do?
Assuming there were a pulse and the patient were stable (no change in
mental status, chest pain, hypotension, or signs of shock), I would (1) attempt to
determine ifthe rhythm is monomorphic, polymorphic, WPW, Torsades, or of
uncertain etiology. Assuming this were monomorphic ventricular tachycardia I
would: (2) consult a cardiologist; (3) administer adenosine, recognizing that this
would convert 5-10% of ventricular tachycardia rhythms; (4) administer
procainamide or amiodarone (amiodarone is preferred in the presence of known
impaired left ventricular function); and (5) identify and correct any contributing
factors such as hypoxemia, hypovolemia, hypercapnia, hypo/hyperkalemia (taking
HCTZ), hypomagnesemia, hypothermia, hypoglycemia (diabetes), pulmonary
embolism (increased risk ofDVT secondary to obesity and pregnancy), and acid-base
derangements.
Rb: in cardiac disease, you want the patient’s Hot to be around:
Hgb of 10 (30 Hct)
T/F: The two times when the risk of initiating epidural bleeding is highest are during
placement and removal of the epidural catheter.
True. KIM when you have catheter concerns, you can always leave it in until all function comes back (with good labs), and you can do Q1 Hr neuro checks
