• Study reports abnormally high VTE and high bleed risk in critically ill COVID-19 patients and calls for more effective prevention strategies.
  • Clinicians at NHS hospitals are supporting the care of COVID-19 patients with the use of geko™ devices to reduce the risk of blood clots in the most at risk patients.
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Blood clots are a life-threatening complication of the coronavirus, but doctors aren’t sure how to prevent them

24th April 2020

The number of clotting problems related to Covid-19 is unprecedented.

Since the outbreak of the Covid-19 virus, doctors have been forced to rapidly figure out how to treat the infection without a vaccine or medicines that provide cure, and most are still not sure of the best way to get oxygen into the damaged lungs of the most severely ill.

On top is this, they are also having to react to a remarkably high, life threatening blood clot risk affecting the lungs, heart and kidneys in critically ill C-19 patients – and conversely, deal with patients who are unable to actually form blood clots – resulting in a high bleed risk.


The exact cause of the severe clotting remains unclear – the complication is as novel as the virus itself. Doctors do however recognize the clotting pattern and have named the complications: COVID-19-associated coagulopathy, or CAC, which are notably associated with high inflammatory markers in the blood, like D-dimer and fibrinogen and stress to the respiratory system – which in some patients shows no shortness of breath but instead low oxygen in the tissue. This hypoxia (shortage of oxygen) has been compared to the effects of high altitude.

The vast majority of critically ill patients with C-19 have underlying medical problems, such as diabetes, heart disease and high blood pressure. These patients – whether they have coronavirus or not – have a higher tendency to clot than healthy patients. The gut feeling internationally is there’s probably a sub-set of C-19 patients who have abnormal clotting behaviour and that this is happening more frequently than would be expected.

Blood clots are not uncommon in severely ill patients. In intensive care units patients on breathing support and who are sedated have limited ability to move as they heal. Staying still significantly raises the blood clotting risk. This elevated risk was noted in Swine Flu and SARS, in the early 2000s where, as with C-19, most clots originated in the lungs. The difference this time is a clotting rate that is beyond anything seen before.

Ordinarily, doctors would rely on results from robust clinical trials to figure out which C-19 treatments are effective. Right now, however, most evidence is no better than anecdotal. Journals are inundated with opinion pieces and blood clot prevention strategies are reliant on shared clinical experience rather than peer reviewed evidence. Clinicians are basically driving blind on what they call very weak but very compelling data and mostly adopting two options to combat clotting:

Whilst a low dose of blood thinner is considered low risk, giving larger doses can, however, make a patient bleed excessively, which can be deadly. C-19 coagulation guidance therefore advocates stepping-up preventative dosing but reinforces the need for individual patient bleed risk assessment.

In the event of high bleed risk, the guidance also recommends use of mechanical thromboprophylaxis e.g. intermittent pneumatic compression (IPC*) and the geko™ device, when IPC devices are impractical or contraindicated.

IPC devices enclose the leg in a cuff filled with air from an electric pump. The cuff inflates and deflates in a repeating cycle moving blood through the veins towards the heart. The blood flow increase helps prevent the blood clot formation. Whilst IPC devices do not cause the same bleed complications as drug therapy, IPC is not suitable for all patients, due to fragile skin, a recent wound, leg ulcer or allergy to cuff materials. The electronic pump is also moved between patients, requiring decontamination – a potential source of virus transmission if not sterilized fully.

Conversely, the geko™ is a daily disposable, single-use device with no decontamination requirement or re-use between patients, minimizing the risk of infection transmission.

About the geko™ device:

The geko™ device is recommended by NICE (MTG19) and cleared by the FDA. NICE support use of the geko™ for VTE prevention when drugs and other methods mechanical prophylaxis are impractical or contraindicated.

Easy to use, the geko™ is a battery powered, disposable, neuromuscular electro-stimulation device designed to increase blood flow in the deep veins of the leg.

The geko™ device gently stimulates the common peroneal nerve activating the calf and foot muscle pumps resulting in increased blood flow, at rate equal to 60% of walking5, without a patient having to move.

 Highly portable, the geko™ device is:

  • Disposable – no need to sterilise after single patient use.
  • Small in size – no decontamination required compared to other mechanical devices.
  • Easy-to-fit – minimal training.
  • No tripping hazard – no leads or hoses.

The geko™ device is also clinically proven to decrease fibrinogen, D-dimer and tPA levels.

  • Barnes et al (Blood Coagulation and Fibrinolysis 2015), showed that the geko™ device decreased plasminogen activator inhibitor 1 (PAI-1) levels in patients, augmenting fibrinolysis and therefore reducing the risk of thrombotic events.
  • Jingwei et al (Chin J Bone Joint Injury, Jun 2017, Vol. 32, No. 6), showed that the geko™ device significantly reduced the D-dimer content of blood, an indicator reflecting the bloods hypercoagulability.
  • Huda M. Jawad. The effect of a novel electrical stimulation method for improving lower limb blood flow in healthy volunteers. Showed that the geko™ devices decreases tPA. Thesis. Published 2012.
  • Other studies; (Lavi, Xie) have also shown that using the geko™ to stimulate the muscle pumps of the lower leg has a beneficial vascular systemic effect.
  • The geko™ is also clinically proven to prevent VTE in immobile acute stroke patients: Williams et al. The use of the geko™ device and the activation of the foot and calf pumps for prevention of venous thromboembolism in patients with acute stroke.

Whilst NICE guidance recommends use of geko™ device in reducing the risk of deadly blood clots, results from other clinical studies, describing the ability for the geko™ device to increase tissue oxygen levels and support kidney function, demonstrates the impact increased systemic blood flow – generated by geko device – can have in an intensive care environment beyond DVT prevention.


Sue Davenport- VP Marketing & Communications
24th April 2020

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