Characteristics of study subjects
From November 15th, 2020 to January 10th, 2021, 84 patients were enrolled (51 M, mean age 62.8 ± 12.0 years). Table 1 summarizes the baseline characteristics of the cohort. Most patients had one or more comorbidities (22.6% were obese, 23.8% had diabetes, 32.1% hypertension, 8.3% COPD).
Table 1
Baseline characteristics of the enrolled patients
Age
|
62.8 ± 12.0
|
Gender (M:F)
|
51 : 33
|
Number and type of comorbidities
|
Mean number 1 ± 0.8
Hypertension 27 (32.1%)
Obesity 19 (22.6%)
Diabetes 20 (23.8%)
COPD 7 (8.3%)
Neoplasms 3 (3.6%)
Immunodepression 2 (2.4%)
|
Days from symptoms onset
|
8.0 ± 3.0
|
Reported symptoms
|
Fever 81 (96.4%)
Cough 49 (58.3%)
Shortness of breath 29 (34.5%)
Fatigue 20 (23.8%)
GI symptoms 17 (20.2%)
Anosmia/ageusia 11 (13.1%)
|
Pulse oximetry (%)
|
96.8 ± 1.5
|
PaO2/FiO2 ratio
|
357 ± 38
|
Respiratory rate (breaths/min)
|
16.3 ± 1.8
|
HRCT > 25%
|
35 (41.7%)
|
C-reactive protein (mg/l)
|
49.1 ± 25.2
|
NLR
|
5.5 ± 4.6
|
D-dimer (mg/l)
|
877 ± 805
|
COPD chronic obstructive pulmonary disease; GI Gastrointestinal; HRCT high-resolution computed tomography of the chest; NLR neutrophil/lymphocyte count ratio |
At admission, the mean duration of symptoms attributable to SARS-CoV-2 infection was 8.0 ± 3.0 days. The most common reported symptoms were fever (96.4%), cough (58.3%), shortness of breath (34.5%), fatigue (23.8%), anosmia/ageusia (13.1%) and gastrointestinal involvement (20.2%). The mean peripheral oxygen saturation was 96.8 ± 1.5 %, the mean respiratory rate 16.3 ± 1.8 per minute, and the mean PaO2/FiO2 ratio 357.5 ± 38.6. A significant proportion of patients had an involvement > 25% at HRCT (41.6%). All patients were discharged after a mean ED stay of 16.3 ± 14.6 hours, with the above-mentioned instructions and a scheduled follow-up visit.
Main results
Six (6) patients (7.1%) were re-hospitalized before the planned visit (5 M, mean age 67.6 ± 9.04 y) after a mean 1.3 ± 0.5 days at home. Of the 78 patients that attended the first follow-up visit after a mean 3.3 ± 1.1 days from the index admission, only 1 had to start oxygen support at home. The peripheral oxygen saturation was 96.6 ± 1.8 %, the respiratory rate 16.5 ± 3.7 per minute, and the mean PaO2/FiO2 ratio 375.3 ± 55.1. Most patients were receiving heparin (82%) and steroids (74.3%). The majority of patients filled out the diary (88.4%), but only in 13/69 diaries warning signs were noted (18.8%). Four patients (5.13%) had to be admitted, 23 (29.5%) were deferred for a further visit and 51 (65.4%) were definitely discharged from hospital care. Of the 23 patients that had been referred to a second visit, 4 (17.4%) had to be admitted before the planned follow-up after a mean 4.5 ± 1.9 days. Of the 19 patients that attended the second visit after a mean of 7.4 ± 2.3 days from the index admission, only 2 (10.5%) needed oxygen supplementation at home. The majority of patients were still on heparin (73.7%) and steroids (68.4%). At the end of the hospital evaluation, 14 (73.6%) patients were definitely discharged, 1 admitted for persistent fever and 4 further deferred for another follow-up visit. Of the 17 patients that were managed in more than one follow-up visit, 14 showed a reduction trend or, at least, stationary in the lung ultrasonographic score. All patients were finally discharged after the third hospital visit. The mean duration of the ambulatorial management was 4.6 ± 2.7 days. Details of management of the single patients are summarized in Figs. 1 and 2.
At the 30-day follow-up call, all but one patients were alive. The deceased patient was a 84-year-old woman that had to be admitted after the second visit because of hypoxemic respiratory failure. After a hospitalization that lasted 12 days (6 in the Intensive Care Unit and 6 in the Sub-intensive Care Unit), she was discharged home. Two days later she was referred to ED for fever, chills, myalgias and shortness of breath. The investigations showed the presence of Enterococcus Faecium in the urine and Acinetobacter Baumannii in the lower respiratory tract. She died of septic shock after 36 hours.
A total of 15/84 (17.8%) patients had to be admitted by the end of the follow-up window. The mean duration of hospitalization was 6.1 ± 2.5 days. All but 3 institutionalized patients (one still receiving low flow oxygen supplementation) were at home at the time of the phone call. The 66 patients that could answer were also asked to rate the ambulatory service on a 10-point scale, with 10 representing the best possible. Overall, they rated the service with a mean of 9.1 ± 1.5 points.
Table 2 summarizes the comparisons between patients that have been hospitalized and patients that were managed home, considering the variables at the index admission and at the first follow-up visit. Overall, there were no differences between the two groups at the index admission except for age (higher for the hospitalized group). Conversely, considering only patients that attended the first follow-up visit (n = 78), the group that had been hospitalized showed higher mean NEWS2, lower peripheral oxygen saturation at rest and after a walking test, lower PaO2/FiO2 ratio and, more importantly, their diary was more likely to be positive for warning signs while at home.
Table 2
Difference between patients that have been hospitalized or patients managed at home, at the index admission (n = 84) or the first follow-up admission (n = 78)
INDEX ADMISSION
|
Hospitalized patients (n = 15)
|
Home-managed patients (n = 69)
|
p
|
Age
|
69.5 ± 10.6
|
61.5 ± 11.9
|
.01
|
Male
|
10 (66.7%)
|
41 (59.4%)
|
ns
|
Number of comorbidities
|
1.2 ± 0.7
|
0.9 ± 0.8
|
ns
|
Days from symptoms onset
|
8.4 ± 2.7
|
8 ± 2.1
|
ns
|
NEWS2
|
0.8 ± 0.7
|
0.7 ± 0.8
|
ns
|
Pulse oximetry (%)
|
97.2 ± 1.5
|
96.8 ± 1.5
|
ns
|
Post-effort pulse oximetry (%)*
|
95.7 ± 1.5
|
95.3 ± 1.9
|
ns
|
PaO2/FiO2 ratio
|
356.5 ± 33.5
|
357.8 ± 39.9
|
ns
|
HRCT > 25%
|
5 (33.3%)
|
30 (43.5%)
|
ns
|
C-reactive protein (mg/l)
|
4.0 ± 3.4
|
5.1 ± 3.6
|
ns
|
NLR
|
6 ± 5.7
|
5.4 ± 4.4
|
ns
|
D-dimer (mg/l)
|
728 ± 485
|
910 ± 859
|
ns
|
FOLLOW-UP ADMISSION
|
Hospitalized patients (n = 9)
|
Home-managed patients (n = 69)
|
p
|
Age
|
70.6 ± 11.9
|
61.5 ± 11.9
|
.03
|
Male
|
5 (55.6%)
|
41 (59.4%)
|
ns
|
Number of comorbidities
|
1.1 ± 0.7
|
0.9 ± 0.8
|
ns
|
Days from symptoms onset
|
11.4 ± 3
|
11.3 ± 3.4
|
ns
|
NEWS2
|
1.5 ± 1.6
|
0.2 ± 0.5
|
< .001
|
Pulse oximetry (%)
|
94 ± 2
|
97 ± 1.5
|
< .001
|
Post-effort pulse oximetry (%)*
|
91.4 ± 3.4
|
95.7 ± 2.4
|
< .001
|
PaO2/FiO2 ratio
|
314 ± 36
|
384 ± 51
|
< .001
|
HRCT > 25%
|
2 (22.2%)
|
30 (43.5%)
|
ns
|
Warning at the diary§
|
6 (85.7%)
|
7 (11.3%)
|
< .001
|
NEWS2 Nationally Early Warning Score 2; HRCT high-resolution computed tomography of the chest. Data were analysed by t test or chi square as appropriate. *measured after Quick Walking Test; §Only 69 patients filled out the diary as instructed. |
At univariate analysis, no variables were significant predictors of hospitalization within the follow-up period at the index ED admission, except for age (OR 1.06, 95% CI 1.01–1.11). Considering the first follow-up visit, age (OR 1.11, 95% CI 1.00-1.23) and NEWS2 (OR 7.76, 95% CI 1.76–36.1) were significant predictors of hospitalization after adjusting for gender and number of comorbidities (Table 3).
Table 3
Results of the logistic regression model: predictors of hospital admission at the first follow-up visit (n = 78)
Variable
|
OR
|
95%CI
|
St. err
|
Z
|
p
|
Age
|
1.11
|
1.00-1.23
|
0.05
|
2.09
|
0.037
|
Gender (M)
|
0.50
|
0.04–5.58
|
0.62
|
-0.55
|
0.579
|
Number of comorbidities
|
0.51
|
0.15–1.72
|
0.31
|
-1.07
|
0.283
|
NEWS2
|
7.76
|
1.66–36.1
|
6.09
|
2.61
|
0.009
|
NEWS2 Nationally Early Warning Score 2; OR Odds Ratio |
We next compared the group of patients that have been managed with the Early Discharge and Re-Evaluation protocol and a historical cohort of patients that were admitted to the ED and hospitalized, marched for age, sex, number of comorbidities, evidence of pneumonia at HRCT and absence of respiratory failure (considered as PaO2/FiO2 ratio > 300). The cohorts were comparable for all other variables (data not shown). Although the mean duration of hospitalization was not different between groups (6.2 ± 5.5 vs 8.8 ± 5.2 days), in our cohort only 15/84 (17.8%) patients were hospitalized, compared to the totality of the 63 patients of the historical cohort.