Deep-Venous Thrombosis, Pulmonary Embolism, Venous Thromboembolism
Conditions
Brief summary
The purpose of this study is to determine if fixed dose heparin infusions at a rate of 500 units/hour are sufficient to maintain a target anti-Xa of 0.1-0.35 IU/mL for venous thromboembolism (VTE) prophylaxis in patients undergoing microvascular surgery. Additionally, a pilot protocol has been developed to titrate these heparin infusions to ensure patients have sufficient VTE prophylaxis. All patients will be enrolled in the observational arm of the study and receive anti-Xa level monitoring. Patients with out-of-range anti-Xa levels will cross over to the interventional arm of the study and receive real time heparin infusion dose adjustments per the pilot protocol. The primary outcome measured will be the percentage of patients with anti-Xa levels in the target range of 0.1-0.35 IU/mL while on a heparin infusion at 500 units/hour.
Interventions
Patients will have steady state anti-Xa levels drawn at least 6 hours after initiation of heparin infusion. Patients with out of range anti-Xa levels will receive real time heparin dose adjustment followed by repeat anti-Xa levels.
Patients will be placed on heparin infusions per their surgeon's discretion.
Sponsors
University of Utah
Study design
Allocation
NON_RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
PREVENTION
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Patients undergoing surgical procedures * Initiation of a heparin infusion at a rate of 500 units/hour intraoperatively or postoperatively
Exclusion criteria
* Age \<18 years old * Pregnant * Incarcerated * Mentally disabled
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Number of Participants With Anti-Xa Levels Within Target Range (0.1-0.35 IU/mL) | Through study completion, an average of 1 year. | Anti-Xa levels are used to monitor anticoagulant therapy. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Number of Rate Adjustments | Through study completion, an average of 1 year. | Heparin rate adjustments were made for out of range anti-Xa levels (\<0.1 and \>0.35) |
Countries
United States
Participant flow
Pre-assignment details
All 20 patients that were enrolled in the standard heparin dose arm crossed over into the real time heparin dose adjustment arm per the pilot protocol with undetectable anti-Xa levels (\<0.10).
Participants by arm
| Arm | Count |
|---|---|
| Standard Heparin Dose Followed by Dose Adjustment The investigators will identify surgical patients placed on fixed dose heparin infusions at their attending surgeon's discretion-the proposed research will not dictate the initiation of the heparin drip intraoperatively. However, the investigators will identify patients already on heparin, evaluate steady state heparin anti-Xa levels and adjust patient's dose if necessary based on steady state anti-Xa levels.Steady state anti-Xa levels will be drawn at least 6 hours after initiation of heparin infusion. Goal anti-Xa levels will be 0.1-0.35 IU/mL. Patients with identified out of range levels will receive pharmacist-driven real time heparin dose adjustment and will receive follow-up steady state anti-Xa levels. Anti-Xa level monitoring will be discontinued when in range peak levels are obtained, when heparin infusions are discontinued at surgeon discretion, or when the patient is discharged. | 20 |
| Total | 20 |
Baseline characteristics
| Characteristic | Standard Heparin Dose Followed by Dose Adjustment | — |
|---|---|---|
| Age, Categorical <=18 years | 0 Participants | — |
| Age, Categorical >=65 years | 0 Participants | — |
| Age, Categorical Between 18 and 65 years | 20 Participants | — |
| Race and Ethnicity Not Collected | — | — Participants |
| Sex: Female, Male Female | 13 Participants | — |
| Sex: Female, Male Male | 7 Participants | — |
| Weight | 20 Kilograms | — |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 0 / 20 | 0 / 20 |
| other Total, other adverse events | 1 / 20 | 1 / 20 |
| serious Total, serious adverse events | 1 / 20 | 1 / 20 |
Outcome results
Primary
Number of Participants With Anti-Xa Levels Within Target Range (0.1-0.35 IU/mL)
Anti-Xa levels are used to monitor anticoagulant therapy.
Time frame: Through study completion, an average of 1 year.
| Arm | Measure | Group | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|---|
| Standard Heparin Dose Followed by Dose Adjustment | Number of Participants With Anti-Xa Levels Within Target Range (0.1-0.35 IU/mL) | Standard Heparin Dose | 0 Participants |
| Standard Heparin Dose Followed by Dose Adjustment | Number of Participants With Anti-Xa Levels Within Target Range (0.1-0.35 IU/mL) | Dose adjustment | 12 Participants |
Secondary
Number of Rate Adjustments
Heparin rate adjustments were made for out of range anti-Xa levels (\<0.1 and \>0.35)
Time frame: Through study completion, an average of 1 year.
Population: During the dose adjustment period, anti-Xa levels were monitored and dose adjustments made per the pilot protocol.
| Arm | Measure | Value (MEAN) |
|---|---|---|
| Standard Heparin Dose Followed by Dose Adjustment | Number of Rate Adjustments | 4.5 Rate adjustments |