EDUCATION CORNER

Anesthetic Management of Craniopharyngioma in a 19-Year-Old COVID-19 Suspect: Clinical Decision Making and Dilemmas

Sung Min Kim, MD; James Blair, DO; and Letha Mathews, MD
Vanderbilt University Medical Center, Nashville, Tennessee

Dr. Kim
Sung Min Kim, MD
Dr. Blair
James Blair, DO
Dr. Mathews
Letha Mathews, MD

Introduction
Coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) which was first reported in Wuhan, China and has since developed into a global pandemic. As of this writing, COVID-19 has produced more than 4 million cases world-wide with > 280,000+ deaths.1 With the cases increasing daily, the United States has become the epicenter of the disease with almost 1.4 million cases and >82,000 deaths.2 Patients who are immune compromised, e.g., the elderly and those with comorbidities – diabetes, hypertension, COPD, OSA, etc. – may be the most susceptible. Patients commonly present with cough, fever, and shortness of breath. Other symptoms may include sore throat, headache, muscle pain, and new loss of taste or smell.3 In the extreme, the condition may progress to pneumonia requiring intubation, intensive care and could result in death.4

Otherwise healthy patients who have been in relatively close contact with a carrier, may contract the virus and present with very mild or even no symptoms.5 It is this aspect of COVID-19’s clinical profile that makes it dangerous to healthcare workers, especially anesthesia providers during direct airway management. Infected patients are at higher risk of developing perioperative morbidity and mortality.6

We discuss the decision-making process involved in the care of a 19-year-old male with a history of wet cough and fever (a COVID-19 suspect) for open pterional craniotomy and resection of a sellar mass.

Case Description
The patient is a right-handed, previously healthy 19-year-old male who was referred for neurosurgical and neuroendocrine evaluation of a newly diagnosed cystic, 2 cm sellar mass compressing the optic apparatus. The patient had subtle visual decline over the preceding eight months, but in the immediate three months prior to evaluation, had more rapidly deteriorating vision necessitating urgent surgery. Ophthalmologic evaluation prior to admission found bitemporal hemianopsia and a brain MRI demonstrated a 2 cm cystic mass emanating from the pituitary stalk, likely representing a craniopharyngioma.

Routine preoperative telephonic and laboratory assessment, eight days prior to surgery, were unremarkable, except for an elevated PTT (39.8), which was repeated and found to be normal. Except for visual changes, neurological exam was unremarkable. COVID-19 screening performed six days pre-op revealed a score of one. He denied shortness of breath but confirmed a productive cough (1 pt.). He continued to have a cough up to the day of surgery.

Neuroendocrine evaluation was without symptoms of adrenal insufficiency, diabetes insipidus, or secretory abnormality, though he did report bilateral tinnitus. He was 182.9 cm tall and 67.3 kg attaining normal pubertal development. Of note at his initial evaluation at the referring hospital, the patient reportedly had a productive cough and fever for the two weeks prior to that evaluation. He was placed on oral steroids for one week prior to surgery. COVID-19 testing from the referral hospital was performed eight days prior to the procedure which was negative.

This 19-year-old was scheduled for a right pterional craniotomy and right posterior orbitotomy for resection of craniopharyngioma. During the preoperative discussion with the surgical team, it was determined that surgery was urgent due to his progressively worsening vision. He was treated as a person under investigation for COVID-19 (PUI) since the surgery would involve frontal sinus drilling, an aerosol generating procedure (AGP), and he continued to have a productive cough.

During the preoperative evaluation we were faced with the following clinical dilemmas:

  • Considering that the patient had a score of one on screening, should we repeat COVID-19 testing prior to surgery?
  • Considering that the patient has been symptomatic, but SARS Co-V2 negative, should we assume that patients is COVID-19 negative?
  • What should be the options for airway management – pre-oxygenation/intubation and extubation?
  • Would you consider deep extubation in a COVID-19 suspect patient after craniotomy to minimize aerosolization at extubation?
  • Should the patient be treated as a Covid-19 suspect in the postoperative period?

Anesthetic Description
Routine pre-op check was unremarkable except as noted in pre-hospital assessment.  Patient appeared calm and was fully aware of his PUI status. He understood the risks and benefits of surgery.  Airway was a Mallampati Grade 2 with adequate mouth opening and full range of motion. Pre-op vital signs and pulmonary and cardiac exams were within normal limits.  Preoperative chest x-ray performed on the morning of surgery was unremarkable. His temperature was normal and reported no fevers for the last four days.

The OR was prepared for droplet and contact precautions per our institutional COVID-19 protocol. Patient was brought to OR by the anesthesia team and standard ASA monitors were placed.  Due to his PUI status, the anesthetic plan included a designated, PPE-protected COVID-19 airway team, who performed induction and intubation (7.5 mm OET) with standard McGrath Mac 4 x 1 with Gr 1 View. Following our COVID-19 protocol, all personnel other than the two members of the airway team waited outside the OR during induction until airway was secured and five minutes had passed.  An arterial line and an additional large bore IV were placed after securing the ETT. The patient was then positioned supine with head fixed in Mayfield head clamps. All personnel in the OR had N-95 masks and full PPE during the entire procedure, since the surgery involved frontal sinus fenestration. Anesthesia for the seven-hour case consisted of infusions of propofol, sufentanil, lidocaine and bolus rocuronium with inhaled isoflurane in oxygen and air. A right pterional craniotomy was performed to remove the perisellar mass without any adverse events. Intraoperative management was uneventful.

The extubation plans were no different from routine craniotomy except to exercise AGP precautions.  However, on emergence after reversal with sugammadex, the patient had to be restrained and sedated with 30 mg of propofol after he became very agitated and difficult to control.  It was not possible to extubate with a face shield or mask over the patient’s face. Once he calmed down and was stable, he was transported to the neurosurgical intensive care unit without further event by using a dexmedetomidine drip with nasal oxygen and face mask. He was discharged home on POD 4 with a prednisone and dexamethasone taper after an uneventful hospital stay. He was given strict instructions to monitor for adrenal insufficiency and diabetes insipidus.

Discussion
The discussion will focus primarily on COVID-19 status and perioperative implications.

  • Do we assume COVID-19 negative with a negative test, even if the patient is or has been symptomatic?

According to Consensus of AANA, ASA, and APSF

“Virus-carrying droplet particles become aerosolized into finer particles by airway procedures such as laryngoscopy, intubation, extubation, suctioning, and bronchoscopy, as well as by coughing and sneezing. These airway procedures and exposures carry a higher risk of infection for anesthesia professionals and other healthcare workers and require the use of rigorous PPE and environmental protection”.7 These situations include:

  • When caring for a patient with known or suspected COVID-19 infection
  • When patients with known or suspected COVID-19 infection need to be transported
  • When performing procedures on patients with known or suspected COVID-19 infection

PPE and Safety Precautions
Due to close patient contact and the need for airway instrumentation, anesthesia professionals are at increased risk of exposure and infection for all diagnostic, therapeutic, and surgical procedures. Also, identification of who is COVID-19 positive or negative with certainty is not possible in the setting of clinical care, especially if there is community transmission. Therefore, ASA recommends as optimal practice that all anesthesia professionals should utilize full PPE appropriate for aerosol-generating procedures for all patients when working near the airway.7
ASA and APSF has released a joint statement on perioperative testing for the COVID-19 Virus  Centers for Disease Control (CDC) guidance. “Discontinuation of Transmission-Based Precautions and Disposition of Patients with COVID-19 in Healthcare Settings (Interim Guidance)” advises that transmission-based precautions may be discontinued by healthcare facilities when patients have resolution of fever and respiratory symptoms and: have two negative COVID-19 tests more than 24 hours apart; or resolution of fever and respiratory symptoms for at least 72 hours and at least seven days since initial symptom presentation.7,8

Our patient continued to have a cough but had no fever and his COVID-19 test was done eight days prior to arrival at our institution. Therefore, we decided to treat him like a person under investigation (PUI) and follow institutional protocol based on ASA and APSF and CDC guidance.7,8,9 Additionally the surgeon had planned on drilling of the frontal sinus to access the tumor. Surgery in the sinus and air space carries a high risk for AGP generation for prolonged periods of time.  This would apply to all endoscopic surgeries such as “transphenoidal approach to pituitary tumors and other sellar masses”.  Most of the data to support this is anecdotal. However, a recent study from Massachusetts Eye and Ear Infirmary titled Endonasal Instrumentation and Aerosolization Risk in the Era of Covid-19: Simulation, Literature Review, and Proposed Mitigation Strategies concluded, “prolonged proximity to the patient and the evident concerns related to drilling indicate that endoscopic skull base procedures carry distinct risks”.10 Recommendations include these procedures be classified as “AGP and PPE protocols should reflect the unique dangers of aerosol based infectious transmissions to the team”.

What Should be the Options for Airway Management -Pre-Oxygenation/Intubation and Extubation?
Protection of anesthesia providers and other personnel in the room is a priority while caring for COVID-19 confirmed or suspect cases. All personnel, other than the airway team,. should leave the operating room to reduce the risk of aerosolized spread and need for full PPE. Anesthesia providers should wear fit tested N95 respirator masks, goggles and gown or powered air purifying respirator (PAPR) during direct airway management.  In addition, precautions should be performed to avoid manual ventilation and potential aerosolization.

Preoxygenation should be performed for a minimum of five minutes with 100 % FiO2 with a High Efficiency Particulate Air (HEPA) filter in place.  A high-quality heat and moisture exchanging filter, fitted between either the facemask and breathing circuit or the facemask and reservoir bag, will remove at least 99.97% of airborne particles greater than 0.3 microns in diameter. All PUI patients should undergo a rapid sequence induction with trained anesthesiology staff, in order to improve the rate of first attempt successful intubation.

If ventilation is required, the use of a well-sealed mask and small tidal volumes are necessary. Intubation should be performed by the most experienced anesthesia provider in the team, especially if the patient is hemodynamically unstable or if a difficult airway is suspected. In our case, the airway team consisted of a senior faculty and resident who managed the airway without any problems. A video laryngoscope should be utilized if available to maximize the distance between the intubator and the patient’s oropharynx. The laryngoscope should immediately be re-sheathed after intubation by using the double glove technique. All used airway equipment should be placed in a double zip locked plastic bag and removed for decontamination and disinfection. All staff needs to carefully remove PPE without self-contamination.

During extubation, there is a high risk of aerosol generation and all non-anesthesia staff should once again leave the room. CDC environmental infection control guidelines include airborne contaminant removal times of 99% to 99.9 % efficiency based upon air exchange rates per hour.11 This may help guide the post intubation pause for room cleaning after an AGP.

Deep vs. Awake Extubation After Neuro Case in a Suspected COVID-19 Patient?
Following neurosurgical procedures, it is a common and safe practice to do a full neurological exam prior to extubation. Deep extubation is rarely done after craniotomies. But in the COVID-19 era, the usefulness of deep extubation could be debated as extubation is an AGP. Extubation after a patient is fully awake has the possibility of patient coughing, being agitated and delirious as was the case in this patient. To minimize aerosol contamination, patients could be extubated deep provided patient’s respiratory pattern is normal with adequate minute ventilation, is hemodynamically stable, has no increased risk of aspiration and no expectation of neurological injury resulting from surgery. The plan for deep extubation should be discussed with the surgical team.

To minimize agitation and delirium we could use certain drugs such as narcotics, alpha-2 agonists, such as dexmedetomidine (DEX). Due to its lack of respiratory depression and salutary cognitive benefits, a DEX infusion would be an appropriate addition to the anesthetic regimen in this case. DEX reduces propofol requirements, can be infused up to and even through emergence (0.2 – 0.7 mcg/kg/hr.), and may substantially aid in a quiet calm emergence.12,13

brainPost-Op Management-Does the patient need to continue to be treated as COVID-19 suspect?
The patient should be treated as a PUI since he reported a productive cough and did not have a COVID-19 test within 72 hours prior to surgery. This would involve use of additional resources in the Neuro Intensive Care Unit and healthcare workers who care for the patient should wear PPE. In our patient, the suspicion of index was low, however because we had not had a confirmatory negative COVID-19 test, we chose to treat him as a PUI.

Conclusion

  • Patients who are infected with SARS-CoV-2 are at increased risk for perioperative morbidity and mortality
  • Aerosol and droplet precautions should be exercised while caring for patients with suspected or confirmed COVID-19 and during intubations and extubations as part of a general anesthetic to protect healthcare workers (HCW). Surgery involving sinuses and endoscopic nasal surgeries are also considered high risk for aerosol generation. 
  • All patients scheduled to undergo elective surgery should ideally be tested for Covid-19, but a negative test by itself is not necessarily reassuring because of the possibility of false negative tests.
  • Viral shedding may occur up to three days before a patient may become symptomatic and these asymptomatic carriers cause risk to the people in the community and healthcare workers.
  • Anesthesia providers caring for COVID-19 confirmed or suspect patients should have a well thought out plan consistent with national and institutional guidelines to provide the best care for patients and protect HCWs.

References

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