Jenshen Cheng, Susmita Roy Chowdhury, Aliviya Dutta, R Ponampalam

1 SingHealth Emergency Medicine Residency Programme, Singapore Health Services, Singapore 2 Department of Emergency Medicine, Singapore General Hospital, Singapore

Dear editor,

The coronavirus disease 2019 (COVID-19) pandemic has enveloped the globe with ferocious pace, prompting lockdowns of countries and continents. Consequently, up to one-third of the world’s population is living in some forms of coronavirus mass quarantine, which brings new and unprecedented challenges to healthcare systems worldwide. One of these is the potentially deleterious effects of physical inactivity due to enacted restrictions.

A period of physical inactivity and prolonged immobility is recognized as one of the major risk factors for the development of venous thromboembolism (VTE).[1]Other risk factors include a prior VTE, use of oral contraceptives,obesity, thrombophilia, smoking, recent long-haul f lights,and malignancy.[2]In this report, we present a case of a 40-year-old man who developed an extensive pulmonary embolism (PE) associated with a significantly changed lifestyle and decreased mobility due to lockdown measures.

CASE

A 40-year-old physical education teacher (body mass index 26.5 kg/m2) was seen at the emergency department(ED) for shortness of breath associated with reduced effort tolerance and diaphoresis of three days’ duration.He denied any chest pain or palpitations. There were no recent respiratory symptoms or fever. In addition,he did not have leg swelling, trauma, or recent surgical procedures. His past medical history was unremarkable.No family history of pro-thrombotic disorders existed.He had no recent ingestion of new medications,recreational drugs, or traditional medication. He gave a history of having traveled to Bali (approximately 3-hour flight duration) a month prior to his ED consultation upon his return to Singapore. He was placed on stay home notice (SHN) for 2 weeks, equivalent to home selfisolation, which he completed uneventfully. However,this resulted in significantly reduced physical activity status. His usual baseline physical activities had involved daily 3-hour exercise regiments with his students,including running and football as well as the occasional 1-hour evening jogs every other day. During his home quarantine period, the patient was involved in deskbound work for 9 hours consecutively with occasional toilet breaks, with the remaining 5–6 hours of the day being spent on watching TV, as well as 1–2 hours naps daily. There was no history or overt signs suggestive of dehydration, but he noted a mild decrease in urine output with no change in urine concentration. He did not keep track of his daily fluid intake and output, but he conscientiously tried to drink as much fluid as possible in school but had not been strict about his fluid intake during SHN. He utilized a fan during the day with room temperature hovering around 25–28 °C and had set the air-conditioning at 24 °C at night. After SHN, the patient returned to work for a week, with less strenuous physical education undertakings limited to indoor court activities.On April 7, 2020, Singapore enacted “Circuit Breaker”measures, consisting of restrictions on interactions and movements in the community with complete closure of non-essential services, including schools.This further limited his activities for four days prior to his presentation. Figure 1 is a timeline of events that chronicled the patient’s experience from home quarantine to the ED.

At the ED, the patient was afebrile with a heart rate of 136 beats/minute, blood pressure of 153/116 mmHg,respiratory rate of 32 breaths/minute, and oxygen saturation of 93% on room air. He was otherwise alert,comfortable, and not in distress. Cardiovascular and respiratory examinations were unremarkable. Lower limb examination was normal, with no tenderness, swelling or edema noted. His electrocardiogram (ECG) (Figure 2) showed sinus tachycardia with right ventricular strain pattern and S wave in lead I, a Q wave in lead III, and an inverted T wave in lead III. His chest X-ray was normal.A bedside goal-directed echocardiography (Figure 2) performed at the ED indicated right ventricular dilatation with an RV:LV ratio of 1:1 and demonstrated McConnell’s sign. An emergent CT pulmonary angiogram (CTPA) (Figure 2) showed extensive bilateral PE with saddle embolus and evidence of right heart strain. The patient was admitted to the Cardiothoracic Surgery ICU where he eventually underwent suction thrombectomy and thrombolytic infusion. Ultrasound of the lower extremities showed left-sided superf icial femoral and popliteal deep vein thrombosis (DVT). He was discharged several days later with oral rivaroxaban for six months. His thrombophilia workup was negative with no predisposing etiologies discovered despite an extensive workup.

DISCUSSION

This is the f irst reported case of an association between the pandemic lockdown and life-threatening VTE in the context of a healthy, COVID-19 negative patient.The incidence of this ailment may be substantial when contemplating the widespread imposition of home quarantine and lockdown measures on communities worldwide.

Figure 2. Patient’s ECG, bedside goal-directed echocardiography, and emergent CT pulmonary angiogram.

Figure 1. A timeline of the patient’s experience from home quarantine to the emergency department.

The link between prolonged immobilization associated with a sedentary lifestyle and VTE has been highlighted over the recent decade, with increasing cases of computer-related seated immobility, giving rise to a phenomenon called “eThrombosis” which was first described in 2003.[1]A case-control study by Healy et al[3]in 2010 revealed the 2.8-time increased risk of VTE in those seated at work and on the computer at home for 10 hours in a 24-hour time period, and for at least two hours at a time without getting up. Braithwaite et al[4]carried out a cross-sectional study, which analyzed 200 patients with a history of VTE in the past six months, as well as 200 controls treated for an upper limb injury for the same duration. A multivariate analysis indicated that work/computer seated immobility per hour was correlated with an 8% increased risk of developing VTE. The risk of prolonged seated immobility in cars was described in 2016 after the earthquakes in Kumamoto, Japan.[5]Many victims were reluctant to return to their homes due to the high risk of aftershocks with some choosing to stay in their vehicles. The occurrence of PE was signif icantly higher in the night-in-vehicle group. Therefore, these developments should be considered and reflected in both Wells and Geneva scores to make it relevant in the context of modern PE diagnostics.

Whilst decision aids such as the Pulmonary Embolism Rule-out Criteria (PERC), Wells, and Geneva scores assist with determining the pre-test probability of VTE, research has shown that these are not in any way superior to clinical gestalt.[6]Therefore, the astute physician should consider the diagnosis of PE in young patients who complain of dyspnoea in the context of relative physical inactivity for a variety of reasons.

CONCLUSIONS

The year 2020 will be remembered as a seismic shift in human history for a pandemic that has caused worldwide lockdowns forcing millions to stay indoors.The unintended consequence of this restrained lifestyle measures is an increased risk of VTE. The physician must continue to have a high index of suspicion for acute PE under lockdown conditions.

Funding:None.

Ethical approval:Not needed.

Conf licts of interest:There was no conf lict of interest related to this study.

Contributors:The manuscript has been read and approved by all the authors.