PATIENTS AND METHODS

This observational and retrospective study reviews clinical data from patients who had surgical procedures performed by members of the thoracic surgery department of the 12 de Octubre University Hospital in Madrid during the COVID-19 pandemic. The study analysed all the patients referred for surgery since the first case of COVID-19 was confirmed in our hospital, from 1 March 2020 to 24 April 2020.
We defined 3 periods of activity during the pandemic: an initial period of near-normal activity, an emergency-only period and finally a recovery period when the surgical staff resumed performing some oncological surgical cases.
During the first period, from 1 to 19 March, we continued with our scheduled surgical activity practically without modifications. After 20 March, hospital capacity was surpassed because of the COVID-19 pandemic, which led to the limitation of surgical procedures to emergencies only. From 20 March to 5 April, the second period, only 2 operations were carried out: for pneumothorax with persistent air leak. Until this date, in our hospital, only those patients with respiratory symptoms were screened for infection with SARS-CoV-2 because of the limitations of testing resources. As a result, only 1 patient was screened and had negative test results.
After 5 April, the third period, we developed a screening protocol for patients who were asymptomatic for SARS-CoV-2 infections, described in Fig. 1, in patients who were to undergo surgery. We established several measures before and during admission as well as after the surgical procedure [7, 8]. Before admission, we questioned each patient by telephone to detect those with COVID-19 symptoms. We also requested information about their exposure and confinement status. We recommended that patients record their temperature twice a day, comply with confinement, avoid exposure to family members and go to the hospital the day of the operation with mask and gloves. In the 48 h prior to the surgical procedure, patients went to the hospital for a nasopharyngeal polymerase chain reaction (PCR) test [9] and chest computed tomography (CT).
Figure 1:  Algorithm of screening patients with asymptomatic SARS-CoV-2 disease referred for surgery. COVID-19: coronavirus disease 2019; CT: computed tomography; PCR: polymerase chain reaction; SARS-CoV-2: severe acute respiratory syndrome coronavirus 2. On the day of admission, meaning 1 day before the operation, we confirmed that the patient was asymptomatic, and blood testing was requested with specific parameters for the detection of the SARS-CoV-2: C-reactive protein, creatinine kinase levels, lactate dehydrogenase levels, ferritin, D-dimer, human immunodeficiency virus and complement component serology.
After the surgical procedure, patients were treated in a COVID-free intensive care unit. Once they were moved to a hospital room, contact and droplet precautions were performed. Patients were also placed in an individual room whenever possible. Physical contact with the patient was avoided or minimized by reducing the number of professional staff during each visit and by always performing hand hygiene. Visits from family members were not allowed.
We based the criteria for surgical intervention on the guidelines of the European Society of Medical Oncology [10] and on the treatment protocols for bronchogenic cancer in our hospital [11], both of which are summarized in Table 1. Non-surgical treatment and follow-up of nodules <2 cm and of ground-glass opacifications were chosen because they were not a priority. Finally, all patients likely to have surgery were discussed in a multidisciplinary clinical session using redefined guidelines for surgical priority.
Table 1:  Eligibility criteria for surgical intervention [10]
Priorities in thoracic surgical oncology
T2NO solid tumours naïve from treatment or after induction chemotherapy
Resectable T3/T4 solid tumours naïve from treatment or after induction chemotherapy
Resectable N1/N2 disease naïve from treatment or after induction chemotherapy
Diagnostic procedure such as mediastinoscopy/thoracoscopy/pleural biopsy for diagnostic/staging work-up
Persistent air leak
Evacuation of empyema-abscess
Drainage ± pleurodesis of pleural effusion The following variables were collected from patients who had surgery, some of which are included in Table 2: age, sex, comorbidities, ethnic origin, physical status and oncological diagnosis, procedure, postoperative complications, length of hospital stay, postoperative respiratory symptoms, time from operation to symptoms, PCR test for SARS-CoV-2, chest CT, chest X-ray, need for hospital re-admission and death within 30 days after the surgical procedure.
Table 2:  Demographics of patients who had elective surgical procedures
N = 29 (%)
Age, average (years)  65, 17 (33–83)
Sex, n (%)
 Female  9 (31)
 Male  20 (69)
Ethnic origin, n (%)
 White  28 (97)
 Latin American  1 (3)
Comorbidity, n (%)  21 (72)
 Hypertension  11 (38)
 Dyslipidaemia  10 (34)
 COPD  5 (17)
 Diabetes  5 (17)
 Obesity  3 (10)
 Chronic kidney disease  2 (7)
 Cardiovascular disease  2 (7)
Physical status, ASA classification, n (%)
 I  1 (3)
 II  7 (24)
 III  19 (66)
 IV  2 (7)
Oncological status, n (%)  25 (86.2)
 Lung cancer  16 (55)
 Pulmonary metastases  4 (14)
 Mesothelioma  2 (7)
 Mediastinal lymph nodes  3 (10)
ASA: American Society of Anesthesiology; COPD: chronic obstructive pulmonary disease. A postoperative follow-up consultation is normally carried out 2 weeks after discharge. During the pandemic, our institution became a COVID-19 hotspot, so to reduce exposure to the virus, we performed remote consultations by telephone [12] 1 week after discharge. We also added questions to the follow-up telephone consultation to screen for COVID-19 respiratory symptoms. If COVID-19 symptoms were detected, we recommended that the patient go to the emergency room. Once in the emergency room, the patient was examined and if clinical suspicion of COVID-19 was high, diagnostic tests (chest radiography and PCR) were performed.

Ethics statement
This article is a description of our clinical practice and outcomes during the COVID-19 pandemic and does not constitute human subject research. According to the 12 de Octubre ethics committee for clinical research, there was no need for institutional review board approval.