Blood Volume Analysis
Conditions
Brief summary
Hypotensive Anesthesia is a type of regional anesthesia performed routinely at our hospital. This type of anesthesia reduces the average arterial pressure. Benefits include reduced bleeding and lower risk of blood clots. The purpose of this study is to determine the effect of intravenous fluids administered with hypotensive anesthesia on your blood volume. With this parameter we will be able to understand how much of your blood is lost because of bleeding and how much of the drop is related to dilution. Study hypothesis: Hemodilution associated with intravenous fluid substitution during hypotensive anesthesia results in decreased postoperative hemoglobin (Hb) levels
Detailed description
Recent technology allows the measurement of patients' total blood volume with 98% accuracy within 90 minutes or less. This is key to understanding the effect of hypotensive anesthesia on patients undergoing total hip arthroplasty. The drop in blood pressure enhances the dilutional effect of intravenous fluid given during the procedure. Increases in TBV could result in decreases of postoperative hemoglobin. Understanding the effect of hypotensive anesthesia on postoperative hemoglobin levels and TBV will enhance our understanding of postoperative blood management and transfusion triggers.
Interventions
RADIATION1mL of I-131 Human Serum Albumin is injected prior to the measurements
Sponsors
Hospital for Special Surgery, New York
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
PREVENTION
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
50 Years to 75 Years
Healthy volunteers
No
Inclusion criteria
* Non- inflammatory degenerative joint disease of the hip * Patients scheduled for unilateral primary total hip arthroplasty * Age between 50 and 75 years * Hypotensive Spinal-epidural anesthesia with systolic BP \< 95 and diastolic BP \< 65. * Adequate intraoperative fluid loading: a minimum of 3 L within 6 hours of surgery
Exclusion criteria
* Pregnant women or nursing mothers. * Women of childbearing potential not using adequate birth control methods * Known hypersensitivity to I-131 albumin or any other component of the Volumex injection kit * Blood coagulopathies resulting in a hypocoagulable state (hemophilia, von Willebrand disease, etc.) * Blood coagulopathies resulting in a hypercoagulable state (factor V leiden, antithrombin III deficiency, protein C deficiency, protein S deficiency) * Patients on anti-coagulants (coumadin, plavix, pradaxa, heparin) * Congestive Heart Failure (at least one medication to treat congestive heart failure) * Coronary artery disease (s/p bypass, stent or AMI) * Kidney insufficiency (creatinine \> 1.5) * Aortic or mitral valve disease * Pulmonary hypertension * Revision Hip Surgery * Inadequate intravenous fluid substitution within the first 6 hrs (\<3 liters) * Inadequate hypotensive anesthesia (mean arterial pressure above 65 for more than 33% of the surgical time
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change in Total Blood Volume | preoperatively and 6 hours postoperatively | The primary outcome is the change in total blood volume (TBV) during the first 6 hours after primary THA utilizing hypotensive anesthesia. Preoperative TBV will be compared to values 6 hours postoperatively. |
Other
| Measure | Time frame | Description |
|---|---|---|
| Change IN Plasma Volume PV | preoperative and 6 hours postoperatively | An indicator dilution technique was used to measure the blood volume, plasma volume and red cell blood volume. Approved by the Food and Drug Administration in 1998, the BVA-100 blood volume analyzer (Daxor Corp.) is a semi-automated system for blood volume analysis. Prepared standards and injectates were used. The injectate consists of 31I-labeled HSA (370- 1,295 kBq \[10-30 mCi\]) in saline. Measurement was performed directly before surgery in the holding area and 6 hours after surgery. Each time, before injection of the tracer a baseline sample was taken. After injection of the tracer via standard i.v. line, the first sample was drawn from an arterial line after 12 minutes waiting time. Afterwards every 6 minutes a sample was taken. In a whole 5 samples were sent for analysis to Daxor® Corp.. Each sample is counted in duplicate. |
Countries
United States
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| Pilot Study 14 patients (7men, 7 women) between 52 and 74 years were enrolled in the study (Table 1).
Exclusion criteria were blood coagulopathies, medication with anti-coagulants, coronary artery disease, congestive heart failure, kidney insufficiency (creatinine \> 1.5 mg/dl), aortic or mitral valve disease, pulmonary hypertension, and known hypersensitivity to the tracer.
All of them underwent total hip arthroplasty by one high-volume surgeon using a posterior or anterior approach. | 14 |
| Total | 14 |
Baseline characteristics
| Characteristic | Pilot Study |
|---|---|
| Age, Continuous | 63.8 years |
| Sex: Female, Male Female | 7 Participants |
| Sex: Female, Male Male | 7 Participants |
Adverse events
| Event type | EG000 affected / at risk |
|---|---|
| deaths Total, all-cause mortality | 0 / 14 |
| other Total, other adverse events | 0 / 14 |
| serious Total, serious adverse events | 0 / 14 |
Outcome results
Primary
Change in Total Blood Volume
The primary outcome is the change in total blood volume (TBV) during the first 6 hours after primary THA utilizing hypotensive anesthesia. Preoperative TBV will be compared to values 6 hours postoperatively.
Time frame: preoperatively and 6 hours postoperatively
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Pilot Study | Change in Total Blood Volume | 487 ml | Standard Deviation 455 |
Other Pre-specified
Change IN Plasma Volume PV
An indicator dilution technique was used to measure the blood volume, plasma volume and red cell blood volume. Approved by the Food and Drug Administration in 1998, the BVA-100 blood volume analyzer (Daxor Corp.) is a semi-automated system for blood volume analysis. Prepared standards and injectates were used. The injectate consists of 31I-labeled HSA (370- 1,295 kBq \[10-30 mCi\]) in saline. Measurement was performed directly before surgery in the holding area and 6 hours after surgery. Each time, before injection of the tracer a baseline sample was taken. After injection of the tracer via standard i.v. line, the first sample was drawn from an arterial line after 12 minutes waiting time. Afterwards every 6 minutes a sample was taken. In a whole 5 samples were sent for analysis to Daxor® Corp.. Each sample is counted in duplicate.
Time frame: preoperative and 6 hours postoperatively
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Pilot Study | Change IN Plasma Volume PV | 214 ml | Standard Deviation 324 |