A 28-year old woman with a term pregnancy struck her head during a fall in a stairway. She was initially stunned, and recovered. Then she became unconscious during a CAT scan. She is scheduled for craniotomy for epidural hematoma, with possible cesarean section. Blood pressure is 180/110 mm Hg, pulse is 56, respirations are 12, and temperature is 36.5 degrees centigrade. Hemoglobin is not yet available.
I. Neurological evaluation
1. What can you predict about her intracranial pressure?
2. Is it important to confirm it preoperatively?
3. Why is she hypertensive?
4. Should her blood pressure be reduced preoperatively?
II. Fetal status:
1. Is her baby in jeopardy? Explain.
2. How do you assess fetal well being?
3. Will you prepare for intraoperative fetal monitoring?
III. Laboratory evaluation
1. What laboratory work is necessary?
2. Why do you want these labs?
3. The hematocrit returns, and it is 28%. What is the significance of this?
4. How does this affect your management?
1. Should she receive intravenous anesthetic for intubation, or should intubation occur first?
2. What induction agent would you use? Explain.
3. Would you use muscle relaxant?
4. Which muscle relaxant would you use, and why?
5. Describe maternal and fetal effects of muscle relaxant.
6. Which other adjuncts would you use, and why?
II. Ventilation management
1. You are asked to hyperventilate the patient immediately, to decrease intracranial pressure. What are the fetal effects?
2. How would you measure maternal CO2?
III. Maintenance for craniotomy
1. Fetal heart tones are satisfactory. What is the best drug that preserves maternal cerebral welfare in this case?
2. Compare and contrast barbiturates vs narcotics vs inhalational agents.
3. What are your blood pressure goals?
4. How would you achieve this?
IV. Fluid management
1. The surgeon requests mannitol. Do you agree? Explain.
2. What are the maternal and fetal maintenance fluid requirements?
3. What amount of fluid will you give?
4. How will you monitor volume status intraoperatively?
5. Blood pressure decreases to 110/60 mm Hg with induction of anesthesia. How will you manage this? Explain your rationale.
V. Arterial hypoxemia
1. Oxygen saturation decreases to 90%. What is your differential diagnosis?
2. What is your treatment?
3. Are your concerns altered by the pregnancy? Explain.
I. Extubation criteria
1. In the recovery room, the patient coughs and strains on the endotracheal tube. The blood pressure is labile and is related to her efforts. Should you extubate her?
2. How will you control her blood pressure during this time?
3. How will you decide to extubate?
II. Assessment of jaundice
1. Two days postoperatively, the patient is icteric. The liver is palpable one fingerbreadth below the costal margin. What is your differential diagnosis?
2. What lab tests will you order?
3. How can you establish the diagnosis?
4. How does the liver influence acid/base balance?
The liver metabolizes protein to acid, and metabolizes these to lactate, which is converted to CO2 and then eliminated by the lungs. Liver disease may result in respiratory alkalosis due to central nervous system stimulation, metabolic acidosis due to increased lactate or renal failure, or mixed disorders.
5. How is lactate formed?
Low tissue oxygen delivery results in the anaerobic metabolism of carbohydrate, which produces lactate.
6. What is the differential diagnosis of lactic acidosis?
Common causes include low tissue oxygen delivery and subsequent hypoxia, hypotension, hypovolemia, and sepsis. Less common causes include diabetic ketoacidosis, liver disease, cyanide poisoning, metastatic malignancy, alcohol consumption, and long storage of blood.