Using vital signs measurements to identify patients with COVID-19 who require early continuous positive airway pressure.

BACKGROUND: The coronavirus disease 2019 (COVID-19) can result in severe pneumonia, leading to acute respiratory distress syndrome, which are treated using continuous positive airway pressure (CPAP). Patients must be evaluated quickly to commence early CPAP if required. AIM: To identify patients with COVID-19 in the emergency department (ED) who require early CPAP, using vital signs measurements during triage. METHOD: This was a retrospective, observational, single-centre cohort study of patients with COVID-19 admitted to the ED of a university hospital in Lombardy, Italy, between 21 February 2020 and 30 April 2020. These patients were divided into two groups: those who required CPAP and those did not require CPAP. Recordings of their vital signs were retrieved from triage medical records. The vital signs values recorded in the two groups on their arrival at the ED were compared. RESULTS: Of 601 patients, 120 (20%) required CPAP. It was identified that the typical characteristics of patients requiring early CPAP were: male (P=.013) with a median age of 68 years (P=.000), oxygen saturation of 92% (P=.000), temperature ≥38°C (P=.008), respiratory rate of 26 breaths per minute (P=.000) and had received pre-hospital oxygen therapy before arriving at the ED (P=.000). The CPAP group was divided into two subgroups: patients who had received pre-hospital oxygen therapy and those who had not. The median respiratory rate values between the two subgroups presented a statistically significant difference (P=.004). CONCLUSION: This study identified the characteristics of a typical patient with COVID-19 who requires early CPAP. Based on the results, the authors have devised a triage flow chart that uses selected vital signs measurements (oxygen saturation, respiratory rate and receipt of pre-hospital oxygen therapy) to identify patients requiring early CPAP. This flow chart should be trialled in a prospective study before it is used to inform clinical decision-making.

Diagnostic performance of chest radiography in high COVID-19 prevalence setting: experience from a European reference hospital.

PURPOSE: The study's aim is to analyse the diagnostic performance of chest radiography (CXR) in patients with suspected coronavirus disease 19 (COVID-19). METHODS: We retrospectively considered 826 consecutive patients with suspected COVID-19 presenting to our emergency department (ED) from February 21 to March 31, 2020, in a high disease prevalence setting. We enrolled patients who underwent CXR and rhino-oropharyngeal swab for real-time reverse transcription-polymerase chain reaction (rRT-PCR). CXRs were evaluated by an expert radiologist; a second independent analysis was performed by two residents in consensus. All readers, blinded to rRT-PCR results, classified CXRs positive/negative depending on presence/absence of typical findings of COVID-19, using rRT-PCR as reference standard. RESULTS: We finally analysed 680 patients (median age 58); 547 (80%) tested positive for COVID-19. The diagnostic performance of CXR, interpreted by the expert reader, was as follows: sensitivity (79.0%; 95% CI: 75.3-82.3), specificity (81.2%; 95% CI: 73.5-87.5), PPV (94.5%;95% CI: 92.0-96.4), NPV (48.4%; 95% CI: 41.7-55.2), and accuracy (79.3%; 95% CI: 76.0-82.2). For the residents: sensitivity (75.1%; 95% CI: 71.2-78.7), specificity (57.9%; 95% CI: 49.9-66.4), PPV (88.0%; 95% CI: 84.7-90.8), NPV (36.2%; 95% CI: 29.7-43.0), and accuracy (71.6%; 95% CI: 68.1-75.0). We found a significant difference between the reporting sensitivity (p = 0.013) and specificity (p < 0.0001) of expert radiologist vs residents. CXR sensitivity was higher in patients with symptom onset > 5 days before ED presentation compared to ≤ 5 days (84.4% vs 70.7%). CONCLUSIONS: CXR showed a sensitivity of 79% and a specificity of 81% in diagnosing viral pneumonia in symptomatic patients with clinical suspicion of COVID-19. Further studies in lower prevalence settings are needed.

Prevalence and outcome of silent hypoxemia in COVID-19.

BACKGROUND: In the early stages of COVID-19 pneumonia, hypoxemia has been described in absence of dyspnea ("silent" or "happy" hypoxemia). Our aim was to report its prevalence and outcome in a series of hypoxemic patients upon Emergency Department admission. METHODS: In this retrospective observational cohort study we enrolled a study population consisting of 213 COVID-19 patients with PaO2/FiO2 ratio <300 mmHg at hospital admission. Two groups (silent and dyspneic hypoxemia) were defined. Symptoms, blood gas analysis, chest X-ray (CXR) severity, need for intensive care and outcome were recorded. RESULTS: Silent hypoxemic patients (68-31.9%) compared to the dyspneic hypoxemic patients (145-68.1%) showed greater frequency of extra respiratory symptoms (myalgia, diarrhea and nausea) and lower plasmatic LDH. PaO2/FiO2 ratio was 225±68 mmHg and 192±78 mmHg in silent and dyspneic hypoxemia respectively (P=0.002). Eighteen percent of the patients with PaO2/FiO2 from 50 to 150 mmHg presented silent hypoxemia. Silent and dyspneic hypoxemic patients had similar PaCO2 (34.2±6.8 mmHg vs. 33.5±5.7 mmHg, P=0.47) but different respiratory rates (24.6±5.9 bpm vs. 28.6±11.3 bpm respectively, P=0.002). Even when CXR was severely abnormal, 25% of the population was silent hypoxemic. Twenty-six point five percent and 38.6% of silent and dyspneic patients were admitted to the ICU respectively (P=0.082). Mortality rate was 17.6% and 29.7% (log-rank P=0.083) in silent and dyspneic patients. CONCLUSIONS: Silent hypoxemia is remarkably present in COVID-19. The presence of dyspnea is associated with a more severe clinical condition.

Retinal findings in patients with COVID-19: Results from the SERPICO-19 study.

BACKGROUND: Coronavirus disease 2019 (COVID-19) has been associated to microvascular alterations. We screened the fundus of patients with COVID-19 to detect alterations of the retina and its vasculature and to assess possible correlations with clinical parameters. METHODS: Cross-sectional study. The presence of retinal alterations in patients with COVID-19 and subjects unexposed to the virus was assessed using fundus photographs and their prevalence was compared. Mean arteries diameter (MAD) and mean veins diameter (MVD) were compared between patients and unexposed subjects with multiple linear regression including age, sex, ethnicity, body mass index, smoking/alcohol consumption, hypertension, hyperlipidaemia, diabetes as covariates. The influence of clinical/lab parameters on retinal findings was tested in COVID-19 patients. FINDINGS: 54 patients and 133 unexposed subjects were enrolled. Retinal findings in COVID-19 included: haemorrhages (9·25%), cotton wools spots (7·4%), dilated veins (27·7%), tortuous vessels (12·9%). Both MAD and MVD were higher in COVID-19 patients compared to unexposed subjects (98·3 ± 15·3 µm vs 91·9 ± 11·7 µm, p = 0.006 and 138·5 ± 21·5 µm vs 123·2 ± 13·0 µm, p<0.0001, respectively). In multiple regression accounting for covariates MVD was positively associated with COVID-19 both in severe (coefficient 30·3, CI95% 18·1-42·4) and non-severe (coefficient 10·3, CI95% 1·6-19·0) cases compared to unexposed subjects. In COVID-19 patients MVD was negatively correlated with the time from symptoms onset (coefficient -1·0, CI 95% -1·89 to -0·20) and positively correlated with disease severity (coefficient 22·0, CI 95% 5·2-38·9). INTERPRETATION: COVID-19 can affect the retina. Retinal veins diameter seems directly correlated with the disease severity. Its assessment could have possible applications in the management of COVID-19. FUNDING: None.