Venous thromboembolism (VTE) is frequent in patients in the intensive care unit (ICU). Pharmacologic prophylaxis is sometimes contraindicated, and mechanical prophylaxis is used. The primary objective of the study is to compare Pulsed Electromagnetic Field Therapy (PEMF) with conventional mechanical prophylaxis for the prevention of VTE in patients in the ICU.

This study is a prospective, randomized, open-label, active-controlled study, patients with indication for mechanical VTE prophylaxis or combined mechanical and pharmacological in the ICU from 2 selected sites in Brazil (Vera Cruz Hospital and Felicio Rocho Hospital, both in Belo Horizonte-MG, Brazil) will be enrolled after signing informed consent. All data will be recorded with a pre-established clinical recording file (CRF - RedCap) to demographics, risk factors, and clinical aspects of the patient's comorbidities.

A trained team member will perform clinical diagnosis and standard clinical evaluations, including imaging when indicated. Patients will be considered eligible if they are> 18 years old, have a PADUA score > 4 (medical patients) and/or Caprini > of 3 (surgical patients), and have a contraindication to pharmacological prophylaxis or indication to combined (pharmacological and mechanical VTE prophylaxis).

After signing informed consent, the patients will be screened and included in the study. After ICU admission, the patient will be interviewed by study investigators or trained physicians or nurses; inclusion patients will be randomized to receive either PEMF or intermittent pneumatic compression.

The devices will be placed in the ICUs following institutional standards and operational procedures. After randomization, trained physiotherapy and nurse teams will place and monitor each device. The intermittent pneumatic compression group will use the devices Covidien Kendall SCD 700® (Cardinal Health) or Doctor Life 2600® (Venosan). This group will have the device placed in the lower limbs, following the manufacturer's instructions, and monitored for 24 hours according to previous institutional protocol. This device will be kept full-time working in the patients while in the ICU.

The PEMF will be carried out using the Hyperslim® device. The Hyperslim® device is produced by Medical San (Lageado, RS, Brazil). It generates electromagnetic pulses through its pads, leading to local muscular supra-maximal contractions sustained for several seconds, increasing stress and workload without muscular adaptation. Its pads will be placed in the patient's lower limbs and used for 30 minutes thrice daily.

The critical care team will monitor patients 24 hours/day for VTE signs and symptoms, laboratory changes, and adverse local effects caused by machines like skin lesions, burns, and edema. A tolerability scale will be applied to every awake patient able to answer using a scale: 1= well tolerated; 2= tolerate with little discomfort; 3= tolerate with discomfort; 4= Not tolerated.

At the end of mechanical prophylaxis, patients will be evaluated for thromboembolic events, including diagnosis by imaging, with a mandatory Doppler ultrasound of the lower limbs at ICU discharge and 30 days post-randomization.

The primary efficacy outcome is a combination of symptomatic + asymptomatic VTE events at day 30 post randomization.

Evaluation also includes major bleeding events, defined as leading to transfusion of 2 or more units of blood or packed red cells, decrease in hemoglobin of 2 g/dL, bleeding in critical sites, defined as spinal, epidural, intraocular, intracranial, pericardial or retroperitoneal, local adverse events, including adverse events related to the use of the devices.

For descriptive statistics, mean and SD will be calculated for data following a Gaussian distribution.

The difference in VTE events between the two groups at the end of mechanical prophylaxis and day 30 will be tested using the intention-to-treat principle.

The efficacy analysis tests will be one-sided, with a type I error rate of 2·5%, assuming a two-sided 95% CI. The cumulative incidence of the composite events will be compared between the test and control groups, and the relative risk (RR) or risk ratio will be estimated. For the safety analysis, statistical tests will be two-sided, with a type I error rate of 5% and a two-sided 95% CI.

Tolerability, security, and facility to implement PEMF will be compared with intermittent pneumatic compression using an unpaired t-test.

Inclusion Criteria:

1. Patients > 18 years old in ICU
2. PADUA score> 4 (medical patients) and/or Caprini score> 3 (surgical patients)
3. Contraindication to pharmacological prophylaxis or indication to combined (pharmacological and mechanical VTE prophylaxis)

Exclusion Criteria:

1. Patients < 18 years old in ICU
2. Unable to use mechanical prophylaxis due to trauma, burns, fracture, or problems in inferior members that prevent the use of mechanical prophylaxis
3. Life expectations less than 24 hours

Anonymized participant data can be made available upon requests directed to the corresponding author. Proposals will be reviewed based on scientific merit. After approval of a proposal, data can be shared through a secure online platform after signing a data access agreement.

March 2025 to March 2030

Anonymized participant data can be made available upon requests directed to the corresponding author. Proposals will be reviewed based on scientific merit. After approval of a proposal, data can be shared through a secure online platform after signing a data access agreement.