Prevention, susceptibility, and clinical features of coronavirus disease 2019 in postoperative patients

To the editor,

The coronavirus disease 2019 (COVID-19) has rapidly spread worldwide and is now a global pandemic. Surgeries were curtailed in many hospitals during the pandemic, and the recommendation to delay all elective surgeries was issued in account of the increased mortality rate in peri-operative patients with COVID-19.^{1 , 2}

Before Tongji Hospital of Tongji Medical College, in Wuhan, China was designated to treat patients with COVID-19 and canceled all elective surgeries, few procedural measures were adopted to prevent the spread of SARS-CoV-2 infection form December 15, 2019, to February 15, 2020 in our center. We reviewed 37,783 inpatients with accessible medical documents. The incidence of COVID-19 was 0.028% (7/25,135 patients) among non-surgical patients and 0.158% (20/12,648 patients) among postoperative patients, with a relative risk of 5.685 (P < 0.001; 95% confidence interval, 2.403–13.449) when compared to the non-surgical inpatient counterparts. Anatomically, patients who underwent thoracic operation showed the highest incidence of the infection, with 9 out of 575 patients (1.56%) diagnosed with COVID-19 during the post-surgical periods. And we found a significant increase in neutrophils (P < 0.001), decreased lymphocytes (P < 0.001), and dramatically greater neutrophil to lymphocyte ratio (NLR) (P = 0.001) in the day one after surgery, which demonstrated an immunological change indicating a higher incidence of infection and poor outcomes for COVID-19 patients. And in our analysis, 40% (8/20) of post-surgical patients with COVID-19 developed severe pneumonia, in particular, 66.7% (6/9) of patients who had thoracic surgery progressed to severe pneumonia after COVID-19 diagnosis and three finally died from COVID-19. The laboratory results showed statistical differences in lymphocyte count, prothrombin time, D-dimer, and interleukin-2R between patients with severe pneumonia and mild pneumonia (Table 1 ).

Table 1.

Clinical characteristics of postoperative patients with COVID-19.

	No. (%)			P-valueb
	Total patients (n = 20)a	Severe patients (n = 8)	Mild patients (n = 12)a
Symptom
Fever				0.315
>39 °C	9 (52.9)	6 (75.0)	3 (33.3)
≤39 °C	7 (41.2)	2 (25.0)	5 (55.5)
Cough	9 (52.9)	6 (75.0)	3 (33.3)	0.153
Chest distress	5 (29.4)	4 (50.0)	1 (11.1)	0.131
Dyspnea	5 (29.4)	5 (62.5)	0	0.009
Chest pain	2 (11.8)	1 (12.5)	1 (11.1)	1.000
Weak	5 (29.4)	5 (62.5)	0	0.009
Muscular soreness	4 (23.5)	4 (50.0)	0	0.029
Diarrhoea	2 (11.8)	1 (12.5)	1 (11.1)	1.000
Blood routine
Neutrophils (×109/L)	6.48 ± 4.21	6.58 ± 5.09	6.39 ± 3.59	0.929
Lymphocytes (×109/L)	0.92 ± 0.34	0.72 ± 0.21	1.09 ± 0.35	0.021
Neutrophil to lymphocyte ratio	8.33 ± 7.90	10.32 ± 10.64	6.55 ± 4.25	0.342
Coagulation function
Activated partial thromboplastin time (s)	42.16 ± 7.63	43.51 ± 7.33	40.81 ± 8.19	0.498
Prothrombin time (s)	13.68 ± 1.45	14.45 ± 1.25	12.90 ± 1.25	0.012
D-dimer (μg/L)	4.20 ± 3.93	6.40 ± 4.50	2.00 ± 1.37	0.019
Blood biochemistry
Albumin (g/L)	34.89 ± 4.74	36.04 ± 4.34	33.59 ± 5.16	0.335
Alanine aminotransferase (U/L)	34.40 ± 31.86	44.25 ± 40.05	23.14 ± 14.84	0.199
Aspartate aminotransferase (U/L)	39.53 ± 46.34	53.50 ± 60.65	23.57 ± 12.71	0.093
Lactate dehydrogenase (U/L)	229.60 ± 135.44	262.63 ± 170.95	191.86 ± 74.75	0.083
Inflammation profile
Procalcitonin (ng/mL)	0.09 ± 0.10	0.13 ± 0.12	0.07 ± 0.06	0.066
Erythrocyte sedimentation rate (mm/h)	45.27 ± 27.27	49.25 ± 30.50	40.71 ± 24.59	0.565
Serum ferritin (ug/L)	603.89 ± 610.10	875.78 ± 724.27	332.00 ± 341.92	0.140
C-reactive protein (mg/L)	63.74 ± 63.76	98.43 ± 75.55	36.76 ± 38.32	0.082
Cytokines
Interleukin-1β (pg/mL)				0.462
Increased	2 (15.4)	2 (28.6)	0
Within normal range	11 (84.6)	5 (71.4)	6 (100.0)
Interleukin-2R (U/mL)	781.46 ± 469.84	984.29 ± 557.02	544.83 ± 180.78	0.046
Increased	8 (61.5)	6 (85.7)	2 (33.3)
Within normal range	5 (38.5)	1 (14.3)	4 (66.7)
Interleukin-6 (pg/mL)	31.13 ± 34.78	46.92 ± 41.41	12.70 ± 9.38	0.073
Increased	10 (76.9)	6 (85.7)	4 (66.7)
Within normal range	3 (23.1)	1 (14.3)	2 (33.3)
Interleukin-8 (pg/mL)	17.85 ± 10.32	21.49 ± 12.11	12.76 ± 4.20	0.157
Increased	0	0	0
Within normal range	13 (100.0)	7 (100.0)	6 (100.0)
Interleukin-10 (pg/mL)				0.070
Increased	4 (30.8)	4 (57.1)	0
Within normal range	9 (69.2)	3 (42.9)	6 (100.0)
Tumor necrosis factor-α (pg/mL)	7.50 ± 2.22	7.91 ± 2.59	7.02 ± 1.80	0.491
Increased	5 (38.5)	3 (42.9)	2 (33.3)
Within normal range	8 (61.5)	4 (57.1)	4 (66.7)
Chest image
Scope				0.073
Bilateral	10 (58.8)	7 (87.5)	3 (33.3)
Unilateral	6 (35.3)	1 (12.5)	5 (55.5)
Without signs	1 (5.88)	0	1 (11.1)
Ground glass opacity	16 (94.1)	8 (100.0)	8 (88.8)	1.000
Consolidation	10 (58.8)	8 (100.0)	2 (22.2)	0.002
Pleural effusion	6 (35.3)	4 (50.0)	2 (22.2)	0.335
Clinical course, day
From surgery to symptom	11.5 ± 11.8	9.1 ± 8.2	13.0 ± 13.8	0.670
From symptom to severe type		6.8 ± 4.9
Complication
Acute Respiratory Distress Syndrome	2 (10.0)	2 (25.0)	0	0.147
Abnormal liver function	7 (35.0)	5 (62.5)	2 (16.7)	0.062
Septic	1 (5.0)	1 (12.5)	0	0.400
Others	0	0	0
Co-infection
Other virus	5 (29.4)	0	5 (55.5)	0.026
Bacteria	2 (11.8)	1 (12.5)	1 (11.1)	1.000
Fungus	0	0	0
Others	2 (11.8)	1 (12.5)	1 (11.1)	1.000
Treatment
Oxygen uptake	14 (70.0)	8 (100.0)	6 (50.0)	0.042
Mechanical ventilation	2 (10.0)	2 (25.0)	0	0.400
Antibiotic therapy	18 (90.0)	8 (100.0)	10 (83.3)	0.495
Antiviral therapy	18 (90.0)	8 (100.0)	10 (83.3)	0.495
Glucocorticoid	6 (30.0)	5 (62.5)	1 (8.3)	0.018
Outcome
Destination				0.049
Recovery	17 (85.0)	5 (62.5)	12 (100.0)
Died	3 (15.0)	3 (37.5)	0

Measurement data was presented as mean ± standard deviation.

^aThree mild patients were followed up in out-patient department and symptoms, lab tests and chest images of COVID-19 among these three patients were missing.

^bP values indicate differences between severe patients and mild patients. P < 0.05 was considered statistically significant.

With the fallen curve in a district, it was not appropriate to postpone the elective surgeries indefinitely. Our center resumed elective surgeries from April 1st, 2020. Several managements strategies were adopted to protect surgical patients because of the susceptibility and vulnerability to SARS-CoV-2 infection (Fig. 1 ). These are as follows:

• 1.Ward transformation: The two zones and passages were arranged in general wards: two-zones include the clean area and the semi-contaminated area; two-passages include the passage for medical staff and the passage for patients. The semi-contaminated area acts as a transition to hold new inpatients and monitor the respiratory symptoms while under medical treatment and care for a period of observation (3–7 days).
• 2.Pre-admission screening: Radiological and microbiological tests were conducted among patients and their companions before administrated in the semi-contaminated area of the general ward.
• 3.Enclosed managements: Adopting enclosed managements further eliminated the infection and transmission in the hospital.
• 4.Post-operative monitoring: Monitor the symptoms and laboratory results after receiving surgery according to our previous experience, especially the decreasing lymphocyte count, prolonged prothrombin time, and higher D-dimer.

Fig. 1.

Prevention managements and the data comparison.

The incidence of COVID-19 in surgical patients before and after taking prevention managements.

In conclusion, this study presents the clinical characteristics and severity of COVID-19 of perioperative case series. The learning experiences from managing these patients, some strategies adopted. And we provided practices to prevent COVID-19 among perioperative patients in hospital after resuming surgery.

Declaration of competing interest

The authors declare no conflict of interest.

Appendix A. Supplementary data

The following are the supplementary data related to this article: