Latest posts by the anesthesia consultant (see all)
Clinical Case for Discussion: A 74-year-old man is scheduled for a left carotid endarterectomy. At the conclusion of the anesthetic, his blood pressure rises to a Mean Arterial Pressure (MAP) of 110, and he is unable to move the right side of his body. What do you do?
Discussion: In 19 years of doing vascular anesthesia, I had this happen to my patient two times. The first time it occurred, I wasn’t sure what to do, if anything, about the new neurologic deficits.
Let us assume that you already carried out the textbook approach to anesthesia for carotid thromboendarterectomy (TEA) for this patient. All appropriate diagnostic and therapeutic measures were done to prepare the patient for surgery. His preoperative MAP was 100. During the general anesthetic the MAP was maintained between 90 and 110. The surgeon used a carotid shunt, and during clamping and shunting no hypotension occurred. (These were the circumstances in both the post operative strokes in my patients.) At the conclusion of surgery, you discontinued the anesthetics, and the blood pressure increased as the anesthetic depth lightened. The MAP increased to 110. You extubated the patient awake. Then you noticed that the right leg and arm were not moving. The surgeon returned to the bedside, and said, “I need him back asleep, as fast as possible!”
What do you do at this point? You give additional doses of anesthetic and relaxant, and reintubate the trachea. You may be feeling guilty, wondering if this paralysis is an anesthetic complication. What the surgeon is thinking is, “do I have a diagnosis that I can treat, such as a dissection, a flap, or a clotted carotid artery?” The surgeon may ask you to give a repeat dose of heparin to the patient. After a quick prep and drape, he reopens the skin incision. The surgeon assesses the pulse in the carotid, and may do a Doppler ultrasound exam. Next is an on-the-table angiogram, which shows that both the common and internal carotid arteries are 100% occluded.
The surgeon closes the wound. You discuss the plan with the surgeon. The plan is to keep the trachea intubated to protect the airway. You discontinue the general anesthesia, and substitute a propofol infusion for transport to the ICU.
Per Miller’s Anesthesia, 5th edition, 2000, p 1878, “for carotid endarterectomy, most centers report a perioperative stroke rate of between 3 and 5 per cent. The incidence of perioperative stroke is highest for patients with stroke, lower for patients with transient ischemic attack, and lowest in asymptomatic patients. Neurologic deficits occur most commonly in patients with poorly controlled preoperative hypertension or in those with hypertension or hypotension postoperatively. More than half of these deficits occur more than 4 hours postoperatively.”
If you do hundreds of carotid TEA’s during your career, a non-zero number of patients will have postoperative strokes. As the anesthesiologist, you have control of the patient’s blood pressure and heart rate. Extremes of blood pressure that are outside the range of autoregulation of cerebral perfusion can contribute to cerebral ischemia. But most strokes will be surgical complications. Per Sabiston, (Textbook of Surgery, 2001, p 1348), “neurologic deficits within the first 12 hours of operation are almost always the result of thromboembolic phenomena stemming from the endarterectomy site or damaged internal, common, or external carotid arteries.”
I learned from my experiences not to extubate the carotid TEA patient until he proves he is awake and can move the contralateral extremities. If there is a stroke, you need only to give more drugs to resume anesthesia, instead of the risks of repeat laryngoscopy and intubation as in the case above.
The most popular posts for laypeople on The Anesthesia Consultant include:
The most popular posts for anesthesia professionals on The Anesthesia Consultant include:
Published in September 2017: The second edition of THE DOCTOR AND MR. DYLAN, Dr. Novak’s debut novel, a medical-legal mystery which blends the science and practice of anesthesiology with unforgettable characters, a page-turning plot, and the legacy of Nobel Prize winner Bob Dylan.
In this debut thriller, tragedies strike an anesthesiologist as he tries to start a new life with his son.
Dr. Nico Antone, an anesthesiologist at Stanford University, is married to Alexandra, a high-powered real estate agent obsessed with money. Their son, Johnny, an 11th-grader with immense potential, struggles to get the grades he’ll need to attend an Ivy League college. After a screaming match with Alexandra, Nico moves himself and Johnny from Palo Alto, California, to his frozen childhood home of Hibbing, Minnesota. The move should help Johnny improve his grades and thus seem more attractive to universities, but Nico loves the freedom from his wife, too. Hibbing also happens to be the hometown of music icon Bob Dylan. Joining the hospital staff, Nico runs afoul of a grouchy nurse anesthetist calling himself Bobby Dylan, who plays Dylan songs twice a week in a bar called Heaven’s Door. As Nico and Johnny settle in, their lives turn around; they even start dating the gorgeous mother/daughter pair of Lena and Echo Johnson. However, when Johnny accidentally impregnates Echo, the lives of the Hibbing transplants start to implode. In true page-turner fashion, first-time novelist Novak gets started by killing soulless Alexandra, which accelerates the downfall of his underdog protagonist now accused of murder. Dialogue is pitch-perfect, and the insults hurled between Nico and his wife are as hilarious as they are hurtful: “Are you my husband, Nico? Or my dependent?” The author’s medical expertise proves central to the plot, and there are a few grisly moments, as when “dark blood percolated” from a patient’s nostrils “like coffee grounds.” Bob Dylan details add quirkiness to what might otherwise be a chilly revenge tale; we’re told, for instance, that Dylan taught “every singer with a less-than-perfect voice…how to sneer and twist off syllables.” Courtroom scenes toward the end crackle with energy, though one scene involving a snowmobile ties up a certain plot thread too neatly. By the end, Nico has rolled with a great many punches.
Nuanced characterization and crafty details help this debut soar.
Click on the image below to reach the Amazon link to The Doctor and Mr. Dylan:
Learn more about Rick Novak’s fiction writing at ricknovak.com by clicking on the picture below: