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.

One goal of theanesthesiaconsultant.com is to make the practice of anesthesia safer. The practice of anesthesia on healthy patients is quite safe, but we want to do everything we can to avoid preventable errors.


The safety of anesthesia on ASA I and II patients has been compared to the safety record of commercial aviation. Few passengers board an airplane and worry they will die before they land at their destination. But planes do crash, and so do anesthetized patients.

In August 2107 the journal Anesthesiology published the study “Frequency and Type of Situational Awareness Errors Contributing to Death and Brain Damage,” authored by Christian M. Schulz MD et al. . This was an important study which documented what experienced anesthesiologists already know—although our specialty has never been safer, preventable deaths still occur.

The study analyzed the United States Anesthesia Closed Claims Project database of 10,546 malpractice claims between 2001-2013. A total of 266 cases of brain damage or death during anesthesia care in the operating room under the care of a solo anesthesiologist occurred. Of these 266 cases, 198 (74%) had a situational error by the solo anesthesia provider. Malpractice payments were made in 85% of these situational error cases, compared to only 46% in other cases. The total of 198 patients in 12 years averaged more than16 preventable deaths per year.

What was the definition of a situational error? The article sited three types: perception, comprehension, and projection.

PERCEPTION ERROR. A failure to gather information via history, the patient’s chart, physical exam, diagnostic tests, imaging, or monitors, including the absence of monitors.

COMPREHENSION ERROR. The information was available, but there was a failure to understand and diagnose the significance of information obtained from history, physical exam, diagnostic tests, imaging findings, or monitors.

PROJECTION ERROR. A failure to forecast future events or scenarios based on a high-level understanding of a problematic situation.

Of the 198 situational errors, perception errors were most common (42% of the cases), followed by comprehension errors (29%) and projection errors (29%).

72% of the errors occurred during general anesthetics, 23% occurred during monitored anesthesia care, and 5% occurred during regional anesthetics.

The primary damaging event differed in the 198 error cases vs. the 68 other cases. In the 198 situational error cases, respiratory events were the dominant category (p<.001), including inadequate oxygenation/ventilation (24%), difficult intubation (11%), and pulmonary aspiration (10%). In the 68 non-error cases, cardiovascular events were the dominant category. All the anesthesiologists were single practitioners, that is, they were not part of an anesthesia care team with a nurse anesthetist.

The authors of the study made the following points in their discussion of the findings:

  1. Many perception errors stemmed from lack of or lack of attention to respiratory monitoring. Key respiratory monitors were pulse oximetry and end-tidal CO2 monitors.
  2. Other common perception errors were missing preoperative information, which led to inadequate preoperative evaluation.
  3. The most common comprehension error was failure to comprehend an ongoing clinical difficulty related to respiratory problems.
  4. Many projection errors involved lack of appreciation of difficult airways.
  5. Projection errors also included procedures taking place in inappropriate environments, such as very sick patients having surgery in an office or an outpatient surgery center.

The authors made the following suggestions to decrease preventable errors:

  1. Perception errors may be prevented by regular scanning and processing of all the information available prior to and during every anesthetic.
  2. A “call for help” and the use of cognitive aides (e.g. emergency checklists or an emergency manual) may help when a patient deteriorates.
  3. Situational awareness training can be addressed in anesthesia crisis resource management education, including simulation training.

There were limitations to the Schulz study. The assembled data was retrospective and nonrandom. The Anesthesia Closed Claims Project may not reflect the true incidence of situational errors in anesthesia practice in the United States. As well, the 198 patients found in this study are only those countable via the closed malpractice claims. The true number of uncaptured cases of preventable deaths is unknown.

I have a busy practice of medical-legal consultation. I evaluate 8-10 cases per year of preventable death or brain death, and I’m just one person with one medical-legal practice. I believe there are far more cases that exceed my reach.

The Schulz study listed 11 specific patient case examples of preventable errors. Based on these 11 cases, the multiple legal cases referred to me, my 31 years of practice, and my 25,000 personally administered anesthetics for all types of surgeries and patients, I’m qualified to give advice on how to decrease preventable errors in anesthesia. My advice follows:

  1. I see uninformed preoperative workups leading to errors. Be an outstanding preoperative physician. Your preoperative assessment of each patient needs to be complete and pertinent. Pay special attention to cardiac, respiratory, neurologic, and any other significant medical issues. If you’re uncomfortable with any lack of information, you must acquire that information before you begin an anesthetic. If you need a consultant such as a cardiologist, cancel the case and get a cardiac consult before you proceed.
  2. As part of your preoperative workup, ask every patient if they can climb two flights of stairs. Be wary when administering general anesthesia to any patient who cannot walk up two flights of stairs. If a patient develops shortness of breath at this modest exertion, this is evidence of a lack of cardiac or respiratory reserve. This requires preoperative workup to determine the diagnosis and to apply treatment prior to general anesthesia. Any patient who has significant knee, hip, foot, or back pain or who has claudication that prevents him or her from walking up two flights of stairs has not proven to you that they have adequate cardiac and/or respiratory reserve. A referral to a cardiologist/pulmonologist/internist for preoperative clearance testing may be indicated prior to surgery.
  3. Don’t let surgeons talk you into anesthetizing patients you believe are inadequately worked up for anesthesia. Don’t let surgeons talk you into anesthetizing patients using anesthesia techniques or anesthesia plans you’re not comfortable with. We give mock oral board exams to residents at Stanford, and a common exam question is to try to dupe the resident into doing something unsafe because the surgeon demanded it. The surgeon is not trained in anesthesiology. The surgeon does not pay your malpractice insurance, and he or she will not have to endure your malpractice lawsuit if the anesthetic goes awry.
  4. Don’t let surgeons talk you into anesthetizing patients in inappropriate locations or settings. Be careful anesthetizing sicker patients in offices or in freestanding outpatient surgery centers. These facilities lack ICUs, clinical labs, blood gases, respiratory therapists, radiology, and backup anesthesia professionals. Be wary of performing procedures which are too invasive or too extensive in these settings. Twenty years ago one of our orthopedic surgeons attempted to schedule an 80-year-old female for a total knee replacement in a freestanding outpatient surgery facility which had overnight capabilities. I refused to staff the case, and told him, “Cases like this—that’s why we have hospitals.” He hung up on me, but there were no further requests to schedule similar patients at that facility. There are pressures to perform increasingly difficult procedures on increasingly sicker patients in non-hospital settings. Resist these pressures. There can be no surgery without an anesthetic. Be consistent with the values you learned in your university residency program. These values haven’t changed—they’re called the standards of care—and they reflect what an adequately trained physician will do in any give situation. Stay within these standards of care, and you’re unlikely to ever lose a malpractice lawsuit.
  5. The highest number of malpractice cases I review involve airway disasters. Do not screw up airway management. This includes intubation, extubation, and mask ventilation. I’ve previously written on this topic, and I can’t emphasize it enough.
  6. Because the highest number of malpractice cases I review involve airway disasters, I’d advise you to commit the ASA Difficulty Airway Algorithm to memory. I recommend Dr. Phillip Larson’s approach to the difficulty airway, as presented in the Appendix to Richard Jaffe’s Anesthesiologists Manual of Surgical Procedures. Patients with airway emergencies deteriorate in minutes. Have a plan in mind before you begin.
  7. Because the highest number of malpractice cases I review involve airway disasters, I recommend you always have a videoscope available. All well-stocked hospital operating rooms will have a Glidescope or equivalent, but many freestanding outpatient surgery centers or office-based operating rooms will not. It’s not always possible to predict the difficulty of endotracheal intubation. If you work at facilities or offices without a videoscope, I recommend you carry a disposable single-use Airtraq in your briefcase. The devices are single-use, and can be invaluable or lifesaving when conventional laryngoscopy is unsuccessful.
  8. Keep a reference book of checklists for dealing with anesthesia disasters available in every anesthetizing location. My recommendation is the Stanford Anesthesia Cognitive Aid Group Emergency Aid. Should a disaster occur, all the steps to appropriate treatment are listed so that you can follow those steps.
  9. Review the Stanford Anesthesia Cognitive Aid Group Emergency Manual regularly, and memorize the steps to each algorithm. The checklists exist so that in a disaster clinicians will not forget any steps, but a solid anesthesiologist will know this information by heart. You had to learn all this information to pass your oral anesthesia board exam, so why would you allow yourself to forget them as your career proceeds? Why would you want to be anything less than the safest practitioner you can be?
  10. A high percentage of the malpractice cases I review involve obese patients. Be extra wary when attending to obese patients. Obese patients present multiple difficulties in terms of airway management, placement of anesthesia lines, safety of oxygenation and ventilation both in the operating room and postoperatively, and they also present increased challenges for your surgeon. Anesthetics on patients with a BMI > 30 are more difficult, and anesthetics on patients with a BMI >40 or >50 are always challenging. I refer you to a previous column on the risks of obese patients for anesthesia.
  11. If you’re ever wondering whether or not to place an arterial line for a non-cardiac case, I’d recommend you place one. I was a cardiovascular anesthetist at Stanford for 15 years, and during that time I placed countless radial arterial lines prior to induction. The procedure is relatively painless, and for the sickest patients the benefit/risk ratio is high. The second-to-second feedback regarding hypotension or hypertension can be essential in patients with limited cardiac reserve, in trauma patients, or in patients with shock. An arterial line will be much more difficult to place if you wait until your patient is already hypovolemic, vasoconstricted, or hypotensive. And if the patient’s arms are tucked or if the patient is in a position other than supine, you’ll have restricted access to the radial artery intraoperatively. My advice: if you’re pondering whether or not to place an arterial line prior to inducing a sick patient, just do it.
  12. Be vigilant. The maintenance phase of anesthesia can at times be long, tedious, and boring, but it’s mandatory we stay vigilant for developing problems. Scan all patient monitors and all aspects of the patient during anesthesia care. Look for trends, e.g. increases or decreases in blood pressure or heart rate. Note any decrease in oxygen saturation, airway pressures, or end-tidal CO2 patterns. Diagnose and treat any abnormalities early in their development.
  13. Don’t struggle alone. Call for help early if your patient deteriorates. In anesthesia residency programs, each resident has multiple faculty members and other residents to assist him or her if a patient becomes acutely ill. In community practice there is almost always a second anesthesiologist or a second acute care physician in the facility to help. A second pair of hands can be invaluable in assisting airway or vascular procedures. A second mind is useful in confirming diagnoses and therapies are correct. An anecdote from my own anesthesia practice: an 80-year-old patient developed severe hypertension leading to frothing pulmonary edema just prior to extubation at the conclusion of a twenty-minute elbow surgery. My colleague in the next operating room left his stable anesthetic, arrived in my room, and placed an arterial line while I tended to the heart and lung emergency. Once the arterial line was placed, I was able to acutely titrate a sodium nitroprusside drip to normalize the blood pressure, decrease the afterload, and regain adequate oxygenation. The patient recovered fully. Without my partner’s help, it’s likely the patient would have died of hypoxemia.
  14. I’ve seen several cases of undetected hemorrhagic shock. Don’t be afraid to speak up to your surgeon. If your surgeon is working in the abdomen or the chest and your patient develops an increasing heart rate and a decreasing blood pressure, this could be the presentation of hemorrhage. The surgeon needs to know if the vital signs are deteriorating. If major hemorrhage occurs, you’ll need to insert a second large-bore IV line, get help, and order a Massive Transfusion Pack from the blood bank.

The Schulz study was an important publication. Preventable errors do occur in anesthesia. It’s up to us to do everything we can to make the incidence of preventable errors in our practice approach zero. You’ll keep your patients safe, and you’ll stay away from bad outcomes and malpractice lawsuits.


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