To the Editor,

Coronavirus disease 2019 (COVID-19) which originated in Wuhan city, China in December 2019 has spread to more than 190 countries affecting millionsof people worldwide. COVID-19 is caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) which belongs to CoV β-speciespossessing spike protein and positive-strand RNA. In the majority of patients, infection with SARS-CoV-2 results in asymptomatic or mild disease. However, the disease may cause pneumonia, acute respiratory distresssyndrome (ARDS), and multiple complicationsin a significant number of patients. Also, the morbidity, due to the disease, may last for a few months in some patients. Those patients who recovered from COVID-19 may return to hospitals for elective or emergency surgeries unrelated to the disease. These patients are more susceptible to perioperative complications because of disabilities due to COVID-19, pre-existing comorbidities, and risks associated with surgery and anesthesia. By meticulous planning of anesthetic management according to the patient’s condition and proposed surgery, perioperative complicationscan be reduced. The aim is to address the anesthetic concerns in patients who recovered from COVID-19.

As there is no definitive treatment of the COVID-19, management is mainly supportive depending on the severity of infection. Patients largely return to their previous state of health in 14–21 days but a small number of cases may remain unwell for several weeks.^1,2 Some of the patients who recovered from COVID-19 will have clinical sequelae.³ Approximately 20% of the hospitalized patients get admitted to the intensive care unit (ICU) for severe disease. These patients admitted to ICU may later develop physical and cognitive dysfunction known as post-intensive care syndrome. There have also been instances where patients developed reinfection or there was reactivation due to possibly long-standing viral carriage.⁴ The patients who recovered from COVID-19 who come for the surgery may have a lot of issues which have to be evaluated carefully by anesthesiologists to prevent perioperative complications. Thus preoperative assessment by detailed medical history, physical examination, and analysis of organ function and surgical conditions are necessary for identification of high-risk patients and optimization of patient’s condition before undergoing sedation and anesthesia.

There is evidence that suggests survivors may develop lung fibrosis and damage. Data regarding lung scar after SARS-CoV-2 infection is very limited, but researchers are going on to find out the answer. According to some studies, a computed tomography (CT) scan abnormality persisted 3 months after hospital discharge of COVID-19 patients.^5,6 Other lung function abnormalities like restrictive pattern, muscle weakness, and reduced diffusion capacity were observed at the time of discharge from hospitals.⁷ Patients who recovered from COVID-19 ARDS are at much higher risk of developing lung function impairment. Pulmonary risk assessment is necessary by inquiring about coughing patterns, worsening of dyspnea, and recent infection. Any abnormal respiratory rate, breath sounds, oxygen saturation (SpO2), and peak expiratory flow rate need further investigation for underlying lung pathology. Routine imaging with X-ray and CT scan may not be required in all patients, but it needs to be considered in patients with positive clinical findings. Lung ultrasound can be a useful tool for screening high-risk patients and patients posted major surgery. In severe COVID-19 survivors, pulmonary function tests may provide useful information. These investigations can help in defining the post-COVID-19 lung injury and assist in altering anesthesia plans. Patients may need specific therapy for the optimization of the condition. Patients with persistent bronchospasm should receive bronchodilator at a fixed schedule and those having evidence of bacterial infection require treatment with antibiotics. Incentive spirometry and deep breathing exercise if started before surgery may help in reducing the postoperative complication.

A significant number of COVID-19 patients also have an impact on their cardiovascular systems.⁸ The mechanism for cardiac involvement can be multifactorial resulting from viral myocardial injury, hypoxia, hypotension, and acute systemic inflammatory response.⁹ Both young healthy patients and those with pre-existing cardiovascular diseases may have various cardiac manifestations such as myocardial ischemia, myocarditis, arrhythmias, and cardiomyopathy.^10,11 For patients who recovered from severe COVID-19, cardiac dysfunction can be present for several weeks. It is logical to evaluate the cardiac function before surgery to identify the cardiac abnormality. Also, the severity of cardiovascular dysfunction is directly related to the risk of anesthesia. Preoperative screening to detect any cardiac issues must be done by careful history as some survivors may have complaints of chest pain, dyspnea, and palpitations after COVID-19. Also, clinical signs like peripheral edema, heart murmur, and basal crackles are sometimes present. Based on signs and symptoms, further investigations such as blood tests, an electrocardiogram, and an echocardiogram should be ordered. Cardiology consultation and opinion may be required in cases where there is a diagnostic dilemma. For patients who are on β-blocker or antiarrhythmic, it is prudent to continue their medication during the perioperative period. For patients who are on anticoagulation or antiplatelet agents, dose adjustment before surgery can be considered.

Studies suggest that the human kidney is also affected during SARS-CoV-2 infection. Acute kidney injury (AKI) has been observed in 37% of hospitalized COVID-19 patients and incidence could be as high as 70% in critically ill patients.^12,13 The potential causes of AKI can be due to viral entry to renal cells, microvascular dysfunction, or damage due to hyperimmune responses.^14-16 In around 50% of patients with renal injury, the prognosis is good, and remission occurs in 3 weeks.¹⁷ However, it is still not clear in how many patients the renal dysfunction will persist even after recovery. Therefore, it becomes imperative to check for renal function in patients who have a history of AKI and hemodialysis during COVID-19 treatment.

Venous thromboembolism has also been seen commonly in COVID-19 patients which would be the result of viral-mediated effects or inflammatory responses. Studies from China have shown that thrombotic complications can be seen in up to 30% of cases.¹⁸ How long the hypercoagulable state lasts is still a mystery, so appropriate precaution to prevent deep vein thrombosis should be taken in patients undergoing major surgeries. As neurologic, endocrine, and gastrointestinal systems can also be affected due to COVID-19, and the recovery time is unknown, careful evaluation of these organ systems is also necessary to rule out any abnormality.^19,20

Anesthetic methods and agents should be wisely chosen in COVID-19 recovered patients as some of the patients may have been lasting morbidity. The type of anesthesia will also depend upon the site, type, and urgency of surgery. In addition to standard monitoring like pulse oximetry, capnography, blood pressure monitoring, electrocardiogram, and temperature, advanced monitoring may be required depending on the planned procedure and patient’s condition. Whenever feasible regional or neuraxial anesthesia should be used to reduce chances of pulmonary complications with general anesthesia. Two big advantages of regional and neuraxial anesthesia are that they avoid airway handling and mechanical ventilation. Neuraxial anesthesia also has the benefit of avoiding airway, pulmonary, and hemodynamic complications related to intubation. Regional anesthesia is safe, but for patients having pulmonary impairment secondary to COVID-19, ultrasound guidance helps limit the total dose of local anesthetics in brachial plexus blocks. General anesthesia may still be needed in many patients due to the site of surgery. It alters the pulmonary function by impacting the gaseous exchange and respiratory mechanics.²¹ Anesthetic drugs reduce the ventilatory response of patients to carbon dioxide which makes them prone to hypoxia in the postoperative period. For patients with residual cardiac dysfunction, anesthetic drugs should be selected carefully to maintain in order to avoid any hemodynamic instability. Patients having multiple problems after recovery from COVID-19, or those who are undergoing major surgery need to be monitored in a high dependency unit after surgery.

More research and detailed analysis will be also required to decide the timing of elective surgery for patients recovered from COVID-19. Many times these patients present with post-COVID-19 sequelae which should be assessed for pulmonary, cardiovascular, and renal and venous thromboembolism risks involved in the procedure to be performed under anesthesia. It is crucial to optimize patients before surgery to reduce the risk and closely monitor postoperatively.

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