Exam 1 Session 1 Additional Topics
Topic 1
An urgent c-section is scheduled for a 19 year old patient who is pre-eclamptic and in active labor. She is receiving magnesium and intermittent hydralazine. Blood pressure is 150/110. What would be your choice of anesthesia?
answer
I would utilize a spinal anesthetic.
Why?
With a spinal the patient can be awake for the birth of their child. It avoids the need for intubation for patients who may have a difficult airway. It also allows the use of neuraxial opioids to reduce the use of systemic opioids during the post op period.answer
Discuss the advantages and disadvantages of epidural
answer
There are a few advantages of an epidural over a spinal. An epidural catheter allows for slow and careful titration of local anesthetic which can minimize sudden hemodynamics changes often associated with a spinal. An epidural catheter also allows ongoing administration of local anesthetic which is helpful for cases that are expected to exceed the analgesia time from a single shot spinal. An epidural catheter can also be left in place during the post op period for patients where post op pain control may be difficult.How would you control blood pressure?
answer
I would assess blood pressure over several readings. Many patients with preeclampsia will still experience a drop in blood pressure following neuraxial anesthesia. If the patient’s blood pressure remains elevated I would use intravenous hydralazine or labetalol.
Why?
answer
Anti-hypertensive are administered to prevent strokes. It does not prevent eclamptic seizures. I would use hydralazine or labetalol because it is widely used as first line agents to treat parturients with severe hypertension.
What are your goals?
My goal is to lower the blood pressure around 25% every two hours with the end goal of systolic below 150 and diastolic below 100.answer
Topic 2
A 65 year old man underwent an uncomplicated CABG 16 hours earlier and was extubated 4 hours ago. In the past hour BP fell from 110/70 to 70/50 and CVP rose from 8 to 22. What are the possible etiologies
Possible causes include myocardial infarction, arrhythmia, complete heart block, cardiac tamponade, ischemia reperfusion injury, pulmonary embolism, and tension pneumothoraxanswer
How would you evaluate?
answer
I would first evaluate the patient’s respiratory status to determine if urgent intubation and mechanical ventilation is necessary. Next I would quickly gather additional data. I would look at heart rate, SpO2, pulmonary artery catheter parameters if available, and chest tube output. Then I would order a stat 12 lead EKG, CXR, CBC, BMP, troponin, ABG, Coags and fibrinogen. I would also perform a quick bedside TTE if possible.
What are you next steps in management
Management would ideally be initiated following definitive diagnosis. However, in many cases the patient may be deteriorating too quickly. Initial therapy would focus on hemodynamic support. Despite an elevated CVP which can indicate a state of fluid overload, I would initiate hemodynamic support with a 500 cc to 1000 cc fluid bolus, then a norepinephrine infusion with target MAP of 65.answer
If tamponade is suspected and mediastinal exploration is required how would you provide anesthesia?
I would first consult the surgeon and determine if needle cardiocentesis is a viable option prior to induction
If not, I would have the patient prepped and surgeons gowned and gloved. Then I would either do a inhalational induction or IV induction with Ketamine and maintain spontaneous respiration as long as possible until the pericardial sac is opened.
Once the patient’s hemodynamic status improves, I would paralyze and secure the airway and initiate positive pressure ventilation.answer
Topic 3
A 48 year old male undergoing a radical prostatectomy during general anesthesia. Two hours after the operation, his esophageal temp probe is 34.5 C . Would you treat?
answer
Yes I would treatWhy
answer
Hypothermia can have many adverse consequences. They include coagulopathy, increased surgical infection, prolongation of certain anesthetic drugs, and associated with increased rates of MI.
How?
I would utilize forced air warming commonly known as a bear hugger. I would also use warmed fluids to prevent further cooling.answer
Thirty minutes later it has decreased to 33.5 C. What are your next steps for management
answer
I would continue aggressive measures to raise the patient’s temperature and minimize additional heat loss. Additional measures include warming the operating room, and placing additional forced air warming devices.
Surgeon attributes a problem with bleeding to hypothermia. Agree?
answer
Yes I agree. It is possible that hypothermia is contributing to increased blood loss since hypothermia does cause coagulopathy.
What might be the mechanism? Explain
This is due to reversible impairment of platelet aggregation via reduced release of thromboxane A3, which impairs formation of an initial platelet plug. Hypothermia also reduces the activity of enzymes in the coagulation cascade, which reduces clot formation.answer
How will decreased temperature influence your plan for extubation? Describe
I would first determine if the patient is meeting extubation criteria. If the patient is at risk of ischemic injury, especially a myocardial ischemia, I would keep the patient intubated and sedated until the patient’s core temperature is above 35 degree celcius. If the patient is at low risk of adverse cardiac events, I would extubate and continue aggressive warming measures.answer
50d6b8b @ 2023-06-07