Lung transplantation: Preanesthetic consultation and preparation

INTRODUCTION — Over 4000 lung transplants are performed annually worldwide after increasing steadily for the past decade (figure 1). This topic will discuss the preanesthetic consultation and preparations for lung transplantation.

Guidelines for selection of recipients are discussed in separate topics. (See "Lung transplantation: An overview" and "Lung transplantation: General guidelines for recipient selection".)

Perioperative anesthetic management, surgical techniques, and postoperative management after lung transplantation are discussed in separate topics. (See "Lung transplantation: Anesthetic management" and "Lung transplantation: Disease-based choice of procedure" and "Lung transplantation: Procedure and postoperative management".)

PREANESTHETIC CONSULTATION

Preoperative assessment and communication — Anesthetic management of a patient undergoing lung transplantation is influenced by the planned surgical approach, urgency of the procedure (eg, need for preoperative extracorporeal membrane oxygenation [ECMO]), the patient's preoperative pulmonary status, and clinically significant comorbidities. Some transplant centers find it helpful to have a checklist for preoperative review (table 1).

Assessment of pulmonary status — Preoperative assessment of pulmonary status focuses on the etiology of respiratory failure and preoperative oxygen requirements [1], as well as the presence of pulmonary hypertension [2]. Patients deemed at risk for cardiopulmonary collapse during induction of anesthesia should be identified in the preoperative period [2,3].

Since patients may be on a waitlist for many months prior to receiving an organ, it is important to identify any recent changes in pulmonary status that might impact eligibility for transplantation (eg, untreated or uncontrolled pulmonary infection). Interval COVID-19 infection is discussed below. (See 'Considerations during the COVID-19 pandemic' below.)

Intraoperative management of patients who require high levels of oxygen (>4 L per minute) or airway secretion clearance therapy at home, and those with elevated baseline arterial partial pressure of carbon dioxide (PaCO₂) on arterial blood gases or elevated pulmonary artery pressure (PAP), will be challenging. For patients who have suffered acute deterioration of pulmonary status, preoperative or intraoperative initiation of venovenous (VV) ECMO as a bridge to urgent transplantation may be planned [4]. Management of such intraoperative cardiorespiratory support is discussed in advance with the surgical team. (See "Lung transplantation: General guidelines for recipient selection", section on 'Ventilator dependence and extracorporeal life support' and "Lung transplantation: Procedure and postoperative management", section on 'Extracorporeal life support' and 'Preoperative extracorporeal membrane oxygenation' below.)

Assessment of comorbidities — A number of comorbid conditions can affect lung transplant outcomes (see "Lung transplantation: General guidelines for recipient selection") [5]. These are generally addressed prior to listing for lung transplant. Preanesthetic review involves determining whether the status of comorbidities has changed since the most recent review.

●Anemia – It is important to treat anemia preoperatively when feasible [1].

●Frailty – Also, frailty related to age or chronic end-organ disease is typically identified and treated if possible (eg, physical rehabilitation, nutritional optimization) [6].

●Cardiovascular – Evaluation of cardiovascular status is typically accomplished with echocardiography, which is typically repeated every three to six months to assess right (and left) ventricular function in lung transplantation candidates; right heart catheterization is performed less frequently. In rare cases, results of these studies may determine that the patient is a candidate for heart-lung transplantation rather than lung transplantation. (See 'Need for heart-lung transplantation' below and "Lung transplantation: Disease-based choice of procedure", section on 'Heart-lung transplantation'.)

●Other organ systems – Many diseases that result in end-stage lung pathology requiring lung transplantation are systemic diseases that affect other organs. Examples include:

•Cystic fibrosis is a multisystem disease that can cause end-stage lung disease, as well as hepatobiliary disease, pancreatic disease, and gastrointestinal manifestations that should be evaluated in the preoperative assessment [7]. (See "Cystic fibrosis: Overview of gastrointestinal disease".)

•Pulmonary fibrosis resulting from rheumatologic diseases such as systemic sclerosis (scleroderma) or polymyositis typically has systemic manifestations including chronic kidney disease, cirrhosis, pulmonary hypertension, airway abnormalities (systemic sclerosis), or muscular abnormalities resulting in abnormal response to neuromuscular blocking agents (polymyositis). (See "Clinical manifestations and diagnosis of systemic sclerosis (scleroderma) in adults" and "Clinical manifestations of dermatomyositis and polymyositis in adults".)

•Pulmonary fibrosis resulting from telomerase mutations may result in thrombocytopenia from bone marrow suppression, cirrhosis, or enteropathies [8]. (See "Dyskeratosis congenita and other telomere biology disorders".)

•Sarcoidosis is a multisystem disease that predominantly affects the lung parenchyma and mediastinal lymph nodes, but may also lead to pulmonary hypertension, restrictive cardiomyopathy, cardiac arrhythmias, kidney dysfunction, hepatic disease, and neurologic symptoms. (See "Clinical manifestations and diagnosis of sarcoidosis" and "Overview of extrapulmonary manifestations of sarcoidosis" and "Clinical manifestations and diagnosis of cardiac sarcoidosis".)

Any severe comorbidities that may affect the candidate's suitability for transplantation are discussed with the lung transplantation medical and surgical teams. (See "Lung transplantation: General guidelines for recipient selection".)

Risk for allosensitization — Possible allosensitization is assessed by the lung transplantation team. Current and historical human leukocyte antigen (HLA) antibody screening tests and the specificity of any pre-formed HLA antibodies should be reviewed. (See "Lung transplantation: General guidelines for recipient selection", section on 'Allosensitization' and 'Crossmatching for blood products' below and "Evaluation and treatment of antibody-mediated lung transplant rejection", section on 'Laboratory'.)

Communication regarding planned surgical approach — The surgeon and lung transplantation team determine whether the patient will have a single lung transplant, bilateral lung transplant, or heart-lung transplantation based on underlying disease [9]. The incision may be a transverse thoracosternotomy also known as a clamshell incision (figure 2), unilateral or bilateral anterolateral thoracotomy (figure 3), or median sternotomy (which requires full cardiopulmonary bypass [CPB]) (figure 4). For single lung transplant, the side to be transplanted should be clearly marked.

These decisions influence anesthetic management, as discussed separately:

●(See "Lung transplantation: Anesthetic management", section on 'Overview of surgical techniques'.)

●(See "Lung transplantation: Disease-based choice of procedure".)

In addition, plans for preoperative or intraoperative use of mechanical respiratory or circulatory support influence anesthetic management:

●(See 'Preoperative extracorporeal membrane oxygenation' below.)

●(See "Lung transplantation: Anesthetic management", section on 'Mechanical cardiorespiratory support'.)

●(See "Lung transplantation: Procedure and postoperative management", section on 'Extracorporeal life support'.)

Crossmatching for blood products — We crossmatch four units of packed red blood cells (RBCs) and four units of fresh frozen plasma (FFP) for bilateral lung transplantation or single lung transplantation with planned mechanical cardiorespiratory support, either CPB or intraoperative ECMO.

For single lung transplant surgery without cardiorespiratory support, two units of packed RBCs are typically sufficient.

Pretransfusion testing is required before surgery in order to have compatible blood products available for transfusion once the patient is in the operating room and ready for anesthetic induction. (See 'Planning timing of anesthetic induction' below and "Pretransfusion testing for red blood cell transfusion".)

Although use of perioperative blood transfusion during lung transplantation has decreased over the last few decades, up to 70 percent of lung transplant recipients receive at least one RBC unit within 24 hours of surgery [10,11]. Approximately one-quarter of patients may need massive transfusion (defined >10 units of RBCs within 24 hours) [10]. Patient-related factors for increased transfusion risk include cystic fibrosis, pulmonary hypertension, Eisenmenger syndrome, and low body mass index (BMI), while procedure-related factors include requirement for mechanical circulatory support, bilateral transplantation, or retransplantation procedures [1,10].

Preoperative medication management

Chronically administered medications — General considerations for management of chronically administered medications are discussed in a separate topic. (See "Perioperative medication management".)

Many lung transplant recipients have chronic obstructive pulmonary disease and receive chronic bronchodilator therapy, which is continued in the preoperative period at the usual doses up to the time of surgery. For single lung recipients, these medications are continued after surgery, but can usually be discontinued after bilateral lung transfusion. Some patients may need additional doses of short-acting inhaled bronchodilators in the perioperative period. (See "Anesthesia for patients with chronic obstructive pulmonary disease", section on 'Inhaled bronchodilators and glucocorticoids'.)

For recipients with pulmonary arterial hypertension (PAH), it is critically important to continue throughout the perioperative period all chronically administered medications that are prescribed for pulmonary hypertension. Patients with type 1 PAH are typically receiving parental, oral, and inhaled PAH-targeted therapies (table 2), which should be continued without interruption until CPB is initiated.

These PAH-targeted agents include:

●Prostacyclin pathway agonists (eg, epoprostenol, treprostinil, iloprost, selexipag)

●Endothelin receptor antagonists (eg, bosentan, macitentan, ambrisentan)

●Nitric oxide-cyclic guanosine monophosphate enhancers (eg, the phosphodiesterase-5 inhibitors sildenafil and tadalafil, or the guanylate cyclase activator riociguat).

Inhaled nitric oxide (iNO) may be used in addition or as a substitute for these medications during the perioperative period.

Notably, PAH-targeted therapies, particularly prostacyclin pathway agonists (eg, epoprostenol, treprostinil, iloprost, selexipag) can also cause systemic vasodilation and exacerbate intraoperative hypotension. Treatment with norepinephrine and/or vasopressin infusion is typically necessary to maintain systemic vascular resistance and blood pressure (table 3).

After reperfusion of the lung allograft(s), these targeted therapies for PAH can usually be tapered and discontinued. (See "Anesthesia for noncardiac surgery in patients with pulmonary hypertension or right heart failure", section on 'Management of chronic medications' and "Lung transplantation: Anesthetic management", section on 'Hemodynamic management'.)

Premedication — Any preoperative sedative is cautiously administered in small doses, with continuous monitoring of oxygenation and blood pressure. Lung transplant recipients typically have chronic hypercapnia and are very susceptible to respiratory depression. Development of hypoxemia or more importantly hypercarbia due to respiratory depression increases pulmonary vascular resistance (PVR) and worsens pre-existing pulmonary hypertension and right ventricular (RV) dysfunction. (See "Anesthesia for patients with chronic obstructive pulmonary disease", section on 'Premedication'.)

Planning for postoperative analgesia — At our center, we usually use thoracic epidural analgesia (TEA) for postoperative pain control and place the catheter after reversal of anticoagulation. This generally occurs in the intensive care unit to facilitate tracheal extubation. However, the optimal approach to postoperative analgesia has not been determined and randomized trials have not been performed.

Pain following unilateral or bilateral transverse thoracotomy necessitates planning for postoperative analgesia (see "Anesthesia for open pulmonary resection", section on 'Post-thoracotomy pain management'), and pain after transverse thoracosternotomy (ie, clamshell) incision is particularly severe. No consensus exists regarding the optimal approach to analgesia, and no randomized trials examining this question have been performed [12]. (See "Lung transplantation: Anesthetic management", section on 'Postoperative analgesia'.)

Placement of a catheter for TEA is employed in many centers to reduce the amount of systemic opioid needed for analgesia [12-16]. Placement of a continuous paravertebral block (PVB) catheter is an alternative technique to provide postoperative analgesia after thoracotomy [17-19]. Since PVB is a deep block in a noncompressible space, considerations for timing of catheter placement are similar to those for an epidural in patients receiving anticoagulants. Although the incidence of hemorrhagic complications after PVB is unknown, case reports have described this complication. (See "Neuraxial anesthesia/analgesia techniques in the patient receiving anticoagulant or antiplatelet medication".)

Considerations for timing of TEA or PVB catheter placement include the risk of epidural hematoma, particularly if systemic heparinization for preoperative or intraoperative ECMO or use of CPB is planned:

●(See 'Preoperative extracorporeal membrane oxygenation' below.)

●(See "Lung transplantation: Anesthetic management", section on 'Intraoperative venovenous (VV) ECMO support'.)

●(See "Lung transplantation: Anesthetic management", section on 'Intraoperative venoarterial ECMO support'.)

●(See "Lung transplantation: Anesthetic management", section on 'Use of cardiopulmonary bypass'.)

Thus, in many centers, including ours, postoperative placement of epidural or paravertebral catheters is preferred because the risk of systemic anticoagulation is no longer present [14]. However, institutional preferences and protocols vary, and discussion with the surgical team regarding the planned incision(s), possible need for intraoperative systemic anticoagulation, and likelihood of postoperative mechanical cardiorespiratory support requiring systemic anticoagulation is important. (See "Lung transplantation: Anesthetic management", section on 'Thoracic epidural analgesia'.)

If an epidural catheter or bilateral PVB catheters are placed in the preoperative period, intraoperative administration of local anesthetic is typically avoided as this may result in a sympathectomy with vasodilation and hypotension, thereby making it difficult to maintain a restrictive fluid management strategy (see "Lung transplantation: Anesthetic management", section on 'Fluid and transfusion management'). Thus, initiation of a local anesthetic infusion is generally deferred until the surgical procedure has been completed. (See "Lung transplantation: Anesthetic management", section on 'Postoperative analgesia'.)

Determination of fasting status — Since lung transplant recipients receive notification of a potential matched donor lung within hours of receiving the organ, preoperative fasting may be inadequate to allow for stomach emptying. A transplant is not elective and cannot be postponed since organ ischemic time is ideally minimized to less than six hours to avoid graft dysfunction that is more likely with longer ischemic times. (See "Lung transplantation: Donor lung procurement and preservation", section on 'Steps to optimize lung preservation'.)

If there is inadequate time to adhere to fasting guidelines (table 4), rapid sequence induction of anesthesia is performed, with appropriate additional precautions against aspiration, as described separately. (See "Preoperative fasting in adults" and "Rapid sequence induction and intubation (RSII) for anesthesia".)

Planning timing of anesthetic induction — Perioperative preparation of the transplant recipient and induction of anesthesia are carefully coordinated with donor lung procurement to minimize the time from resection to implantation (ie, cold ischemic time). The recipient proceeds to the operating room after the donor lungs are initially assessed and determined to be of sufficient quality to be suitable for transplantation. During the preoperative period, regular communication between the anesthesiologist and the surgeon or transplant coordinator ensures optimal timing for induction of anesthesia. However, the organ procurement team will make a final determination regarding whether the donor lungs are of sufficient quality to proceed with transplantation only after direct physical examination of the lungs on-site. (See "Lung transplantation: Procedure and postoperative management", section on 'Preparation'.)

Cold ischemic time begins when the donor pulmonary artery supplying the lung is cross-clamped, and ends at reperfusion after implantation in the recipient. Following removal from the donor, lungs are flushed with cold preservation solution, partially inflated, and chilled for transport. Depending on the travel distance from donor to recipient sites, final determination of allograft quality may occur after induction of anesthesia in the proposed recipient. Thus, preoperative discussion with the patient and family regarding final inspection of donor lungs and possible cancellation of the procedure is necessary to set realistic expectations. If the donor lungs do not meet criteria, the procedure is aborted, and the anesthesiology team is notified that the transplant has been cancelled.

The details of donor lung procurement and preservation are discussed separately. (See "Lung transplantation: Donor lung procurement and preservation", section on 'Steps to optimize lung preservation' and "Lung transplantation: Donor lung procurement and preservation", section on 'Normothermic ex-vivo perfusion (after cold static preservation)'.)

SPECIAL SITUATIONS

Preoperative extracorporeal membrane oxygenation — Patients with hypoxic or hypercapnic respiratory failure (eg, partial pressure of oxygen [PaO₂] <60 mmHg, partial pressure of carbon dioxide [PaCO₂] >60 mmHg, pH <7.20) may benefit from preoperative initiation of venovenous (VV) extracorporeal membrane oxygenation (ECMO) as a bridge to transplantation (figure 5 and image 1) [20-28]. Avoiding femoral cannulation by placing a dual-lumen right internal jugular cannula allows for active rehabilitation with ambulation during ECMO support, thereby avoiding deconditioning in patients who are hemodynamically stable and extubated (or breathing spontaneously through a tracheostomy) while awaiting transplantation surgery [29,30]. (See "Extracorporeal life support in adults in the intensive care unit: Overview" and "Lung transplantation: Procedure and postoperative management", section on 'Extracorporeal life support'.)

Much less commonly, a patient may be bridged to transplant with venoarterial (VA) ECMO in the setting of pulmonary arterial hypertension (PAH) and concomitant right ventricular (RV) dysfunction [28]. Although RV function often improves with the reduction in pulmonary vascular resistance (PVR) that occurs after reperfusion of transplanted lungs, assessment of preoperative RV function is necessary to plan likely intraoperative and postoperative pharmacologic and mechanical RV support. The latter option includes either continuing VA ECMO or transitioning to a RV assist device at the conclusion of surgery. Notably, patients with longstanding severe RV failure may not be candidates for lung transplantation alone, but may require a combined heart-lung transplantation.

If ECMO is to be initiated, the anesthesiology team typically provides assistance to accomplish insertion of the necessary cannulae using transesophageal echocardiography [28] as described in detail in a separate topic. (See "Extracorporeal life support in adults in the intensive care unit: The role of transesophageal echocardiography (TEE)".)

Some patients who did not require support in the preoperative period may need to have VV ECMO established electively or urgently during the intraoperative period, as discussed separately (see "Lung transplantation: Anesthetic management", section on 'Intraoperative venovenous (VV) ECMO support') [1,28]. Once initiated, support is typically maintained throughout the transplantation procedure. Intraoperative conversion to VA ECMO or to full cardiopulmonary bypass (CPB) may be necessary in patients with severe PAH [23,28]. (See "Lung transplantation: Anesthetic management", section on 'Intraoperative venoarterial ECMO support'.)

Need for heart-lung transplantation — In rare circumstances, combined heart-lung transplantation may be performed in a patient with both end-stage heart failure and end-stage lung disease refractory to medical therapy, usually due to PAH refractory to treatment and concomitant severe RV failure. Examples include patients with Eisenmenger syndrome or idiopathic PAH [31]. Only 51 heart-lung transplants were performed in the United States in 2022 [32]. Considerations affecting anesthetic management are discussed below, while general considerations for heart-lung transplantation are discussed in a separate topic. (See "Heart-lung transplantation in adults".)

The most common surgical approach for combined heart-lung transplantation is a bilateral thoracosternotomy (ie, clamshell) incision, although a sternotomy may be selected. The procedure is performed with full CPB, with the heart and lungs implanted en bloc.

Special considerations for anesthetic management of these patients include:

●Congenital heart disease – If an intracardiac shunt is present, a bubble-free technique for intravenous (IV) fluids and injection of drugs is critical to avoid cerebral air embolism. Worsening of right-to-left shunt from elevations in PVR during induction of anesthesia may cause hypoxia and is best treated by increasing systemic vascular resistance with vasopressors (norepinephrine, vasopressin, phenylephrine (table 3)) and decreasing PVR by minimizing sympathetic stimulation and treating hypoxemia, hypercapnia, and acidosis. (See "Anesthesia for adults with congenital heart disease undergoing noncardiac surgery", section on 'Precautions to avoid air embolism' and "Anesthesia for surgical repair of congenital heart defects in adults: Management of specific lesions and reoperation", section on 'Left-to-right shunt lesions'.)

●Pulmonary arterial hypertension with right ventricular failure – As noted above, patients with type 1 PAH are typically receiving chronically administered parental, oral, and inhaled PAH-targeted therapies (table 5), which should be continued without interruption until CPB is initiated. (See 'Chronically administered medications' above.)

Considerations during the COVID-19 pandemic — The International Society of Heart and Lung Transplantation (ISHLT) advises that heart and lung transplantation proceed with caution during the coronavirus disease 2019 (COVID-19) pandemic, taking into account the potential risks of virus transmission, high mortality should COVID-19 develop in the recipient, and the loss of an opportunity for transplant should an available organ not be used [33,34]. Vaccination is strongly recommended for eligible children and adult transplant recipients along with anyone living with a transplant recipient. When possible, the vaccination series should be completed two weeks prior to transplant [35].

The ISHLT also advises that patients who contract COVID-19 while on the waitlist for lung transplantation should become inactive temporarily [33]. Reactivation on the waitlist should await resolution of symptoms related to COVID-19 and two successive negative polymerase chain reaction (PCR) tests at least 24 to 48 hours apart.

If a transplant candidate has asymptomatic COVID-19, transplantation should be delayed for 14 days from diagnosis and after two successive negative PCR tests at least 24 to 48 hours apart. This timeframe is based on the higher acuity of heart and lung waitlisted patients and lesser opportunities for organ availability. (See "COVID-19: Issues related to solid organ transplantation".)

Considerations for anesthetic and airway management of patients who might be shedding viral particles are discussed in a separate topic. (See "Overview of infection control during anesthetic care", section on 'Considerations during aerosol-generating procedures' and "Overview of infection control during anesthetic care", section on 'Considerations with COVID-19 or other agents spread by aerosol'.)

INFORMATION FOR PATIENTS — UpToDate offers patient education materials. "The Basics" patient education pieces are written in plain language, at the 5^th to 6^th grade reading level, and they answer the four or five key questions a patient might have about a given condition. These articles are best for patients and families who want a general overview and who prefer short, easy-to-read materials. Here is the patient education article relevant to this topic (see "Patient education: Lung transplant (The Basics)"). (You can also locate patient education articles on a variety of subjects by searching on "patient info" and the keyword(s) of interest.)

SUMMARY AND RECOMMENDATIONS

●Preoperative assessment – Preoperative assessment for lung transplantation focuses on (see 'Preoperative assessment and communication' above):

•Pulmonary status – Including etiology of respiratory failure, presence of pulmonary arterial hypertension (PAH), and preoperative oxygen requirements. (See 'Assessment of pulmonary status' above.)

•Comorbidities – Includes determining whether the status of comorbidities has changed since the most recent review. (See 'Assessment of comorbidities' above.)

•Communication – Includes discussion of the surgical team's planned approach (eg, single lung transplant, bilateral lung transplant, or heart-lung transplant) and planned use of mechanical cardiopulmonary support (eg, extracorporeal membrane oxygenation [ECMO], cardiopulmonary bypass [CPB]). (See 'Communication regarding planned surgical approach' above.)

Some transplant centers find it helpful to have a checklist for preoperative review (table 1).

•Preparing for transfusion – We crossmatch four units of packed red blood cells (RBCs) and four units of fresh frozen plasma (FFP) for bilateral lung transplantation or single lung transplantation with planned mechanical cardiorespiratory support. Two units of RBCs are crossmatched for single lung transplantation. (See 'Crossmatching for blood products' above.)

•Medication management – Chronically administered medications for chronic obstructive pulmonary disease (eg, bronchodilators) are continued throughout the perioperative period and for PAH (eg, pulmonary vasodilators) are continued in the preoperative and intraoperative periods, but are typically tapered and discontinued after reperfusion of the lung allograft(s). Premedication with a sedative is minimized and carefully titrated to avoid worsening hypercapnia and hypoxemia. (See 'Preoperative medication management' above.)

●Analgesia – At our center, we usually use thoracic epidural analgesia (TEA) to control postoperative pain and reduce systemic opioid dosing. We place the catheter after reversal of anticoagulation to reduce risk for epidural hematoma. Other centers use a continuous paravertebral block (PVB). Even if a TEA or PVB catheter is placed preoperatively, dosing with local anesthetics during the intraoperative period is typically avoided to prevent sympathectomy-induced vasodilation and resultant hypotension. (See 'Planning for postoperative analgesia' above.)

●Timing

•Minimize cold ischemic time – Donor lung procurement is carefully coordinated to minimize time from resection to implantation (cold ischemic time). Preoperative communication with the surgeon is necessary before transport of the patient to the operating room to establish that the donor lung has been assessed and is of sufficient quality. (See 'Planning timing of anesthetic induction' above.)

•Fasting – Notification of a potential matched organ within hours of organ availability may not allow a preoperative fasting period adequate for stomach emptying (table 4); thus, rapid sequence induction is frequently necessary. (See 'Determination of fasting status' above and "Lung transplantation: Anesthetic management", section on 'Induction and intubation'.)

●Special considerations

•ECMO for respiratory failure – Patients with hypoxic or hypercarbic respiratory failure (eg, partial pressure of oxygen [PaO₂] <60 mmHg, partial pressure of carbon dioxide [PaCO₂] >60 mmHg, pH <7.20) may benefit from preoperative initiation of venovenous (VV) ECMO as a bridge to transplantation (figure 5 and image 1). The anesthesiology team typically assists with insertion of cannulae to initiate ECMO support using transesophageal echocardiography. (See 'Preoperative extracorporeal membrane oxygenation' above.)

•COVID-19 – Patients who contract COVID-19 while waitlisted for lung transplantation typically become inactive on the waitlist until at least 14 days after initial diagnosis if asymptomatic, or until symptom resolution if symptomatic. In both cases, two successive negative polymerase chain reaction (PCR)-based tests should be documented 24 to 48 hours apart before the patient is reentered on the waitlist. Anesthetic and airway management of possibly infectious patients are discussed separately. (See 'Considerations during the COVID-19 pandemic' above and "COVID-19: Perioperative risk assessment, preoperative screening and testing, and timing of surgery after infection".)