CAN ANESTHESIA MACHINES BE USED FOR ICU VENTILATORS?

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.
email rjnov@yahoo.com
phone 650-465-5997

Can anesthesia machines be used as ICU ventilators for COVID-19 patients?

Yes, they can. 

Every anesthesia machine has a ventilator attached to it. The ventilator is not as complex a device as what is found in the ICU, but an anesthesia machine ventilator is fully capable of ventilating sick COVID-19 patients, who have the severe pneumonia known as Acute Respiratory Distress Syndrome (ARDS). For years physician anesthesiologists have transported sick patients from the intensive care unit (ICU) to the operating room (OR) when patients needed a surgical procedure. These sick patients have been successfully maintained on the anesthesia machine ventilator, and physician anesthesiologists have attended to them.

The most practical way to utilize an anesthesia machine as a ventilator would be to convert the existing operating room into a temporary ICU in this time of the COVID-19 pandemic, when we face a threat of inadequate numbers of ICU beds and ventilators. Who would staff these additional temporary ICUs? It could possibly be the customary staff of the operating room, i.e. a circulating nurse and an anesthesiologist. Ideally there would need to be consultation and care by a critical care attending physician, to make sure the proper management is applied to all of a patient’s physiologic systems, e.g. their heart, kidneys, lungs, their antibiotics and their nutrition.

The American Society of Anesthesiologists (ASA) held an online Town Hall meeting last Thursday night, March 19th, 2020 to discuss anesthesiology information pertaining to the COVID-19 pandemic. The question of using anesthesia machines for ICU ventilators was specifically discussed. ASA President Dr. Mary Dale Peterson said she’d already participated in a conference call with government leadership, including President Trump, regarding the pandemic. She said she’d suggested the use of anesthesia machines as ventilators for COVID-19 patients, as well as an increased role for physician anesthesiologists in the ICU care of infected patients.

A typical anesthesia machine is pictured above. The ventilator aspect of the machine is magnified below:

Anesthesia machine ventilators are capable of delivering variable amounts of oxygen, from room air 21%, to a full 100% oxygen if necessary. Most anesthesia machines are capable of delivering increasing amounts of Positive End Expiratory Pressure (PEEP) up to 20 cmH20, which is often necessary to oxygenate patients with severe ARDS. Anesthesia ventilators can function in volume control mode (by delivering a set volume of a tidal breath), or pressure control mode (by delivering a present inspiratory pressure of each tidal breath).

Anesthesia machines would need to be equipped with an inline bacterial/viral filter on the expiration limb of the disposable breathing hoses, to keep viruses from infecting the machine. This is easily done.

Will anesthesiologists be called to step forward at this time of crisis to man temporary operating rooms that are converted to ICUs? Perhaps. It will depend on the number of critical care MDs who are already available, and whether additional staffing is needed. It will depend on the supply of Personal Protective Equipment (PPE) available. (Asking anyone to step into a COVID-19 ICU without the required PPE is a dangerous request. The ongoing search for more N95 masks, face shields, gowns, and gloves is critical.) It will depend on the ages of the available anesthesia personnel. The death rate for COVID-19 infection increases markedly after age 60, so older anesthetists would be less than ideal. Is there a role for Certified Registered Nurse Anesthetists if ORs are converted into ICUs? Yes.

You can also read an earlier column I wrote on Coronavirus and ICU ventilators.

For more details on anesthesia machines and ventilators, this link will connect you to the website of North American Draeger, a leading manufacturer of anesthesia machines.

Specific information on Draeger anesthesia ventilators can be found here.

DO ANESTHESIOLOGISTS HAVE THE HIGHEST MALPRACTICE INSURANCE RATES?

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.
email rjnov@yahoo.com
phone 650-465-5997

How high are anesthesiology malpractice rates? Do Anesthesiologists pay the highest malpractice insurance rates?

In a word, “No.”

Anesthesia mishaps can lead to critical events such as death or coma, but in recent decades improvements in operating room technology and education have led to fewer such events.

Prior to 1985, anesthesia malpractice claims for death or brain death were most often due to lack of oxygen the patient’s heart or brain.  Two significant breakthroughs arrived in the 1980’s to help anesthesiologists care for you:  1) the pulse oximeter, and 2) the end-tidal carbon dioxide monitor.

The pulse oximeter, developed by Nellcor and Stanford anesthesiologist William New, M.D., is a device that clips to a patient’s fingertip.  A light-emitting diode shines a red light through the finger, and a sensor on the opposite side of the finger measures the degree of redness in the pulsatile blood flow within the finger.  The more red the color of the blood, the more oxygen is present.  A computer in the pulse oximeter calculates a score, called the oxygen saturation, which is a number from 0-100%.  An oxygen saturation equal to or greater that 90% correlates with a safe amount of oxygen in the arterial blood.  A score of 89% or lower correlates with a dangerously low oxygen level in the blood.  The pulse oximeter monitor enables doctors to know, second-to-second, whether a patient is getting sufficient oxygen.  If the oxygen saturation goes below 90%, doctors will act quickly to diagnose and treat the cause of the low oxygen level.  A patient can usually sustain a short period low oxygen saturation, e.g. up to 2 or 3 minutes, without permanent damage to the brain or cardiac arrest by an oxygen-starved heart.

The end-tidal carbon dioxide (CO2) monitor is a device that measures the concentration of CO2 in the gas exhaled by a patient on every breath.  During normal ventilation, every exhaled breath contains CO2.  When no CO2 is measured, there is no ventilation, and the doctor must act quickly to diagnose and treat the cause of the lack of ventilation.

Prior to the invention of these two monitors, it was possible for an anesthesiologist to mistakenly place a breathing tube in a patient’s esophagus, instead of the trachea, and not know of the error until the patient sustained a cardiac arrest.  With the addition of the two monitors, the lack of CO2 (there is no CO2 in the stomach or esophagus) from the end-tidal CO2 monitor immediately indicates that the tube is in the wrong  place.  The anesthesiologist can then remove the tube, resume mask ventilation with oxygen, and attempt to replace the tube into the windpipe.  If the oxygen level to the patient’s blood dips below 90%, this is a second piece of data that indicates that the patient is in danger of brain damage or cardiac arrest.

In addition, in the early 1990’s the American Society of Anesthesiologists created the Difficult Airway Algorithm, which is a step-by-step approach for anesthesiologists to follow when the task of placing a breathing tube for an anesthetic is challenging or difficulty.  This Algorithm dictates a standard of care for practitioners, and this advance in education lowered the number of mismanaged airways.

In the 1980’s, surgical anesthesia claims were 80% of closed malpractice claims against anesthesiologists (American Society of Anesthesiologists Closed Claims database).  By the 2000’s, this number dropped to 65%.   Brain damage represented 9% of claims, and nerve injury accounted for 22% of claims (23% were permanent and disabling, including loss of limb function, or paraplegia or quadriplegia)  Less common claims were airway injury (7% of claims), emotional distress, (5% of claims), eye injuries including blindness (4% of claims), and awareness during general anesthesia (2% of claims).

Decreasing anesthesiologist malpractice premiums reflect the decrease in the number of catastrophic anesthesia claims for esophageal intubation, death, and brain death.

In 1985, the average malpractice insurance premium was $36,224 per year for a $1 Million per claim/$3 Million per year policy.   By 2009, this decreased to $21,480, a striking 40% drop.(Anesthesia in the United States 2009, Anesthesia Quality Institute)

Specialties with the highest risk of facing malpractice claims are neurosurgery (19.1 percent), thoracic and cardiovascular surgery (18.9 percent) and general surgery (15.3 percent). Specialties with the  lowest risks are family medicine (5.2 percent), pediatrics (3.1 percent) and psychiatry (2.6 percent).  Anesthesiologists rank in the middle of the pack, at 7%.  (Malpractice Risk According to Physician Specialty, Jena, et al, N Engl J Med 2011) From 1991 to 2005, this article identified 66 malpractice awards that exceeded $1 million dollars, which accounted for less than 1% of all payments. Obstetrics and gynecology accounted for the most payments (11), followed by pathology (10), anesthesiology (7), and pediatrics (7).

The take-home message is that anesthesia has serious risks, but those risks have decreased significantly in recent years because of improvements in monitoring and education.  Compared to other specialties, the risk of an anesthesiologist being sued is about average among American medical specialties.

 

The most popular posts for laypeople on The Anesthesia Consultant include:

How Long Will It Take To Wake Up From General Anesthesia?

Why Did Take Me So Long To Wake From General Anesthesia?

Will I Have a Breathing Tube During Anesthesia?

What Are the Common Anesthesia Medications?

How Safe is Anesthesia in the 21st Century?

Will I Be Nauseated After General Anesthesia?

What Are the Anesthesia Risks For Children?

 

The most popular posts for anesthesia professionals on The Anesthesia Consultant  include:

10 Trends for the Future of Anesthesia

Should You Cancel Anesthesia for a Potassium Level of 3.6?

12 Important Things to Know as You Near the End of Your Anesthesia Training

Should You Cancel Surgery For a Blood Pressure = 178/108?

Advice For Passing the Anesthesia Oral Board Exams

What Personal Characteristics are Necessary to Become a Successful Anesthesiologist?

 

 

Learn more about Rick Novak’s fiction writing at ricknovak.com by clicking on the picture below:  

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