General characteristics and clinical presentations
A total of 104 outpatients were tested for SARS-CoV2 RT-PCR, including 36 (67.9%) males and 17 (32.1%) females in the positive PCR group and 38 (71.7%) males and 15 (28.3%) females in the negative PCR group. The mean age of the outpatients was 41.22±1.80 and 39.89±1.85 years for positive and negative PCR groups, respectively. General characteristics and clinical presentations are provided in Table 1.
We found a significant difference in the mean respiratory rate and SPO2 between negative and positive PCR groups. SPO2 was significantly lower in the positive PCR group than in the negative group (P = 0.03). However, the mean respiratory rate was significantly higher in the positive PCR group (P =0.001).
The COVID-19 pandemic has presented multiple challenges regarding clinical management. Accurate clinical monitoring is fundamental to inform both patient safety and management decisions. Of particular importance is the monitoring of blood oxygen saturation due to the direct impact of the disease on the respiratory system and complications such as thromboembolic disease.
Oximetry is an indirect way of measuring the oxygen concentration in the blood (i.e., what percentage of the blood is carrying oxygen). Using a pulse oximeter, we can quickly and easily measure oxygen levels and determine whether an individual needs to seek medical help, which is the case when their SPO2 is lower than 92%. Oximetry is a quick, non-invasive method of estimating oxygenation and has other benefits such as being continuous, meaning it can highlight sudden changes in a patient’s clinical status(12).
During the ongoing COVID-19 pandemic, reports in social media and the lay press indicate that a subset of patients is presenting severe hypoxemia in the absence of dyspnea, a problem unofficially referred to as “silent hypoxemia”(13). Oxygen is an essential aspect of treatment for patients with COVID-19 pneumonia. Indeed, the major mechanism for injury and death in COVID-19 is related to hypoxia(14).
Our results, in line with recent findings, certify the importance of SPO2 levels in the diagnosis of patient safety and management decisions. COVID-19 predominantly affects the respiratory system. It shows a wide range of clinical presentations ranging from asymptomatic/mild symptoms (fever, cough, dyspnea, myalgia, fatigue, anosmia, dysgeusia, and diarrhea) to severe illnesses like acute respiratory distress syndrome (ARDS), arterial and venous thrombosis, myocarditis, and varieties of neurological manifestations(15). COVID-19 can cause shortness of breath, lung damage, and impaired respiratory function.
Respiratory rate is a common screening tool used to identify lower respiratory tract infections in clinical settings. Given that COVID-19 impairs and damages the respiratory system, it is reasonable to suggest that changes in respiratory efficiency—and, therefore, resting respiratory rate—might occur in the early stages of infection(16), which is in line with our results.
The reliable monitoring of respiratory rate is also very important for the treatment and management of other respiratory issues like chronic obstructive pulmonary disease (COPD)(17). There was no significant difference in terms of age, sex, and mean pulse rate between the two evaluated groups (P ˃0.05). In line with our results, a case-control study comparing the COVID-19 infected patients and healthy matched controls reported that vital parameters like heart rate, systolic, and diastolic blood pressure showed no difference between the study groups(15).