Detection of Residual Pulmonary Alterations With Lung Ultrasound and Effects on Postoperative Pulmonary Complications for Patients With Asymptomatic SARS-CoV-2 Infection Undergoing Surgeries

Susana González-Suárez; Antonio Barbara Ferreras; Melissa Caicedo Toro; Macarena Aznar de Legarra


BMC Anesthesiol. 2022;22(186) 

In This Article


One hundred three post-COVID-19 patients were included in the study. The average number of days between COVID-19 diagnosis and surgery was 108.56 ± 82.02. The mean age was 60.18 ± 14.95 years. During SARS-CoV-2 infection, the number of days of admission to the ICU was 2.09 ± 8.82, IQR (0–1) and the total days of hospitalization were 14.43 ± 44.69, IQR (2–8). The commorbidities of the patients and their relationship with the pathological ultrasonographic findings and static compliance are shown in Table 1. Surgical and anesthetic characteristics are shown in Table 2.

At the time of surgery, 11.7% of the patients presented atelectasis, and 7.8% presented pleural effusion. The presence of ≥ 3 B-lines were observed in 25 (24%) of the patients. The global mean of B-lines score was 0.71 ± 1.56, IQR (0-0), and in patients with ≥ 3 B- lines was 2.84 ± 1.82, IQR (0–4). Sixteen patients (15.53%) presenting both, B-lines ≥ 3 and pleural thickening.

The global mean of pulmonary compliance obtained in 69 patients who required general anesthesia, was 50.39 ± 13.89 ml/cm H2O. For 15 patients (21.7%) the pulmonary compliance was < 40; for 20 patients (29%) it was between 40–49, and for 34 patients (49.2%) it was ≥ 50 ml/cm H2O. The pulmonary compliance values were higher as the time elapsed between COVID-19 diagnosis and surgery increased (rho= 0.24, p=0.04) (Figure 2). An inverse correlation was seen between pulmonary compliance and B lines (Figure 3) (rho= -0.24, p=0.04).

Figure 2.

Correlation between pulmonary static compliance and time elapsed from COVID diagnostic to surgery

Figure 3.

Correlation between pulmonary static compliance and B lines

The patients with pleural thickening presented more hospitalization days, a need for mechanical ventilation, more incidence of dyspnea, fever, pneumonia, SDRA and a need for vasoactive drugs during SARS-CoV2 infection (Table 3).

The patients with ≥ 3 B-lines had a higher incidence of ARDS, and they needed more days in intensive care unit (ICU) and vasoactive drugs during SARS-CoV-2 infection (Table 3).

There was no association between compliance < 50 ml/cmH2O and clinical course of COVID-19 infection (Table 4).

All patients survived 30 days after surgery. Hospital stay was 5.53 ± 15.67 days. The mean time for IMV was 1.29 ± 7.44, and for NIMV was 0.54 ± 2.13 days. Two patients presented emergent orotracheal intubation due to PPC.

Six patients (5.8%) presented PPC. In these patients, the mean age was 56.50 ± 17.97, one woman and five men (p = 0.17)). One patient was ASA II, four patients were ASA III, and one patient ASA IV (p = 0.05). Three patients presented a degree of type 2 surgical complexity, one patient presented type 3 and two patients presented type 4 (p = 0.32). Five patients with PPC received general anesthesia and one patient endovenous sedation (p= 0.64).

The patients presented six different types of PPC. Two of these patients required emergent orotracheal intubation; whilst only one patient presented several complications simultaneously: PTE, pneumonia, pneumothorax, and bronchospasm, with the need for IMV for 30 days and NIMV for 4 days. Moreover, one patient presented pneumonia, one patient presented bronchospasm, and one patient presented ARDS with the need for IMV for 7 days. Two patients presented atelectasis, one of which required NIMV for 4 days.

PPC and their relationship with pulmonary echographic findings and static compliance are shown in Table 5. Patients with both, ≥ 3 B-lines and pleural thickening, presented a higher occurrence of PPC.

The PnPC were gathered: 4 (3.9%) patients needed vasoactive drugs, 4 (3.9%) patients required a second surgery, 2 (1.9%) patients presented thrombosis, 3 (2.9%) patients presented surgical wound infection, 2 (1.9%) patients presented cardiac alteration and 1 (1%) patient presented renal alterations. 15 patients (14.56%) required red blood cell transfusion and 2 patients (1.94%) required fresh frozen plasma and platelets.