Physician anesthesiologist at Stanford at Associated Anesthesiologists Medical Group
Richard Novak, MD is a Stanford physician board certified in anesthesiology and internal medicine.Dr. Novak is an Adjunct Clinical Professor in the Department of Anesthesiology, Perioperative and Pain Medicine at Stanford University, the Medical Director at Waverley Surgery Center in Palo Alto, California, and a member of the Associated Anesthesiologists Medical Group in Palo Alto, California.

You’re the anesthesiologist assigned to a freestanding ambulatory surgery center (ASC). Are you and the facility prepared for an emergency at a surgery center? Let’s examine this case study:

You meet your first patient of the morning, a 75-year-old female scheduled for lateral epicondylitis release surgery on her right elbow.  You review her medical record and interview her. You discover she had her aortic valve replaced with a small metal valve two years earlier. She is active, although she does experience mild shortness of breath on walking stairs. She is obese, weighing 200 pounds, with a BMI=35. She is on no medications. On physical exam, her vital signs are normal, her lungs are clear, and her heart exam is positive for the clicking sound of a mechanical valve and a 2/6 systolic murmur. She has a thick neck and a large tongue. The surgeon says he will only need to operate for 15 minutes. The patient refuses a regional nerve block, so she’ll need to be asleep.

You attach the standard vital sign monitors, preoxygenate the patient, and induce anesthesia with 150 mg of propofol, 50 micrograms of fentanyl, and 40 mg of rocuronium. You intubate her trachea with a 7.0 tube without difficulty, and place her on a ventilator delivering 1.5% sevoflurane and 50% nitrous oxide.

The patient’s arm is prepped and draped. The surgeon injects 2% lidocaine at the skin incision site, and the surgery begins. Vital signs remain normal with BP=110/70, P=80, and oxygen saturation=99%. The surgery concludes after 17 minutes. You discontinue the sevoflurane and reverse the paralysis with sugammadex. The patient’s blood pressure increases to 150/100 within three minutes. Three minutes later the oxygen saturation drops to 80% and thick frothy fluid bubbles into the endotracheal tube and the circle breathing hoses which connect the patient to the anesthesia machine. The blood pressure is now BP=180/120.

You call for help and attempt to suction the frothy fluid out of the breathing tubes. You listen to the lungs and hear loud rattling rales. You assess that you’re dealing with pulmonary edema (excess fluid in the lungs). The patient’s oxygen saturation drops to 70%. 

A second anesthesiologist responds to your call for help and arrives in the room. You explain what is going on, and while you do, the oxygen saturation becomes unmeasurable and the blood pressure machine fails to give any reading. Your colleague suggests you administer 20 mg of Lasix (furosemide) as a diuretic, and he injects this for you. You continue to ventilate the patient with 100% oxygen, and continue to suction copious fluid out of the patient’s lungs. The ECG monitor descends into a slow agonal rhythm, and when you check the carotid artery at the patient’s neck, there is no pulse. You call a Code Blue and begin CPR compressions on the patient’s chest. After thirty minutes of Advanced Cardiac Life Support (ACLS) drug administration, the pulses have not returned. You have no other therapies to offer, and the patient is declared dead.

Acute pulmonary edema on a chest X-ray

Did this have to happen? No, it did not. In a parallel universe with more competent clinicians, let’s look at how this patient should have been handled:

  1. First off, this case was inappropriate for a freestanding outpatient surgery center. This freestanding outpatient surgery center was located miles from the local hospital, and the hospital resources of an intensive care unit (ICU), respiratory therapists, arterial blood gas analysis, and chest X-rays were not available. The surgery was trivial enough—a brief procedure on the elbow—but the patient had a medical history which was too complex to approve a general endotracheal anesthetic at a freestanding ASC. Typically patients who have had a successful cardiac valve replacement are much improved after their surgery, and complaints of shortness of breath or extreme fatigue—symptoms of inadequate cardiac function—are absent. A 75-year-old patient who complains of shortness of breath on exertion was a poor candidate for anesthesia at an ASC. A pre-operative cardiology consult was indicated, and would likely include an echocardiogram and a stress test. In our parallel universe, the echocardiogram ordered by the cardiologist revealed a small aortic valve diameter—less that one centimeter—and a dilated left ventricle with an ejection fraction (LVEF) of 35% (a severely abnormal value, as the normal left ventricle can eject more than 50% of its volume). This patient with a low LVEF needed to have her surgery postponed until her cardiac function was improved via medications or a further surgical cardiac intervention was done. After that, when and if this elbow surgery ever does occur, it would need to be done in a hospital setting.
  2. What if the anesthesiologist did not adhere to #1 above, and the anesthetic led to pulmonary edema as described above? How could the anesthesiologist better manage the emergency? All acute medical care is managed by A-B-C, or Airway-Breathing-Circulation. In this case the Airway tube was in place. The Breathing was being done by the ventilator, but the breathing tube was occluded by pulmonary edema fluid. The treatment to improve the Breathing was both active suctioning to clear the airway of fluid and medical treatment to reverse the cause of the increased fluid. Diagnosis of the Breathing and Cardiac problems was as follows: discontinuation of anesthesia in this patient, who still had a breathing tube in her trachea as she awakened, stimulated markedly increased blood pressure –> the left ventricle could not eject against this high pressure –> this led to acute left heart failure with resulting backup of fluid into the lungs –> this caused pulmonary edema and dropping oxygen saturation. (Because of her airway anatomy, she was not a candidate for a deep extubation.) Treatment for both the Breathing problem and the Cardiac problem was an emergency afterload reducing drug such as nitroprusside. Every ASC must have a Code Blue cart with emergency drugs and equipment, and the anesthesiologist must call for the cart. He or she instructs one of the RNs to prepare a 250 ml bag of nitroprusside and to attach it to an intravenous infusion pump.
  3. We anesthesiologists are only as good as our monitoring devices. When the oximeter reports very low readings and the BP cuff stops working, we are in big trouble. Anesthesiologists cannot safely administer a potent intravenous infusion such as nitroprusside without an accurate second-to-second monitor of the patient’s blood pressure. One of the anesthesiologists quickly places an arterial line catheter in the left radial artery at the wrist. The arterial line is connected to the monitoring equipment, to reveal that the blood pressure is 240/140, for a mean blood pressure (MAP) of 173 mm Hg. The anesthesiologists connect the nitroprusside drip to the peripheral intravenous line, and infuse the drug to decrease the blood pressure to 140/80 (MAP=100) within minutes. The frothing fluid in the breathing tubes clears, and the oxygen saturation returns to 100%. 
  4. The anesthesiologists then place a central venous catheter in the right internal jugular vein and transfer the nitroprusside infusion to the central line. They titrate small doses of fentanyl and Versed into the peripheral IV line to sedate the patient because immediate extubation is not appropriate, and prepare to transfer the patient via ambulance to the nearest hospital ICU. The original anesthesiologist accompanies the patient in the ambulance to the ICU, while continuing to monitor the patient’s vital signs and manage the blood pressure, sedation, ventilation, and oxygenation.
  5. The patient’s sedation is discontinued the next morning in the hospital ICU, and she is extubated safely. She has no brain damage or cardiac damage. The anesthesiologist visits her that afternoon, and converses with her as she eats her lunch. She has questions about how this could have happened, and he answers each question honestly.

There are multiple take-home messages from this case study:

  1. The preoperative screening of patients at a freestanding ASC is crucial. No one wants to have a Code Blue or a near-Code Blue, miles away from any hospital. Surgery centers manage preoperative screening in various ways, but most community ASCs do not run an in-person preoperative anesthesia clinic. At our ASC, a preoperative caller contacts each patient two days prior to their scheduled surgery, and fills out a comprehensive history form based on the patient’s answers and any medical tests and/or consults available on that patient. If there are positive answers regarding important medical issues such as shortness of breath, chest pain, heart disease, obstructive sleep apnea, morbid obesity, chronic kidney or liver disease, cancer, or previous transplants, then the preoperative caller refers the case to the Medical Director. The Medical Director makes the decision whether the patient is appropriate for the scheduled surgery. If the patient is not appropriate, the case is cancelled two days ahead of time.
  2. If an acute respiratory or cardiac emergency occurs at an ASC, the first move is to call for help from a second anesthesiologist. Two minds and four hands are a better solution. The registered nurses bring a copy of the Stanford Emergency Manual into the room, as well as the code cart which includes the emergency drugs and monitoring equipment.
  3. In a true emergency, diagnosis and treatment must occur within minutes. No anesthesiologist wants to be the doctor who “draws a blank” when their patient is trying to die right in front of them. Stanford’s Dr. David Gaba pioneered acute anesthesia simulator training to improve anesthesiologist performance in emergency settings. You may inquire whether such simulations are available in your geographic area.  
  4. Always manage acute medical emergencies as A-B-C, or Airway-Breathing-Circulation, in that order. In this case the improvement in Breathing required suctioning and afterload reduction, and the improvement Cardiac required arterial line monitoring and afterload reduction.
  5. Realize that short simple surgeries exist, but some short simple surgeries on sick patients present significant anesthetic risks. The anesthesiologist must assess all medical risks and not be swayed by a surgeon who insists this will be “just a short simple case.” If an anesthesiology complication occurs, that surgeon will not likely be blamed, nor will he or she come to your defense. It will be “the anesthesiologist’s fault.”
  6. Every ASC must be prepared for acute unexpected emergencies. The code cart must be stocked with ACLS medications and monitoring equipment for arterial and/or central lines. The ASC should ideally have a copy of the Stanford Emergency Manual, and all drugs and equipment listed in that manual should be available, even though it is not a hospital setting.
  7. It’s important for ASCs to conduct mock-Code-Blue drills on a yearly basis so that staff is prepared when a real emergency occurs.
  8. Depending on cost, an ASC may choose to stock a nitroglycerin drip or a newer potent vasodilator medication such as Cleviprex (clevidipine) rather than nitroprusside in their code cart.
  9. Ideally, anesthesiologists who work at ASCs should also have medical staff privileges at an acute care setting in a hospital, and be performing anesthetics on sicker hospitalized patients there. If an anesthesia provider’s practice is reduced to only healthy patients for outpatient surgeries, that anesthesia provider may become less than competent if a patient develops an emergency in a surgery center.
  10. In case of an emergency at a surgery center, your goal is to stabilize the patient and transfer the patient to the nearest hospital as soon as it is safely possible. The hospital resources of an ICU, respiratory therapists, radiology, cardiology consultation, and a full laboratory service including arterial blood gas analysis are invaluable.

For those readers who are surgical patients, let me reassure you that the vast majority of patients cared for at freestanding ASCs have no anesthesia complications, and many ASCs are staffed by competent anesthesiologists and nurses prepared to save you in the rare event that something goes awry before, during, or after your outpatient surgery.




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