Hyperbaric Oxygen and Outcome After Below Knee Amputations

Study Overview
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Brief Summary
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This study is being conducted to assess the utility of hyperbaric oxygen as an adjunctive treatment to reduce postoperative complications. It is hypothesized that HBO2 given in the immediate postoperative period will reduce postoperative complications in patients undergoing below-the-knee amputations. The objective of this study will be to compare treatment and standard care groups, randomly created of eligible patients, to compare their postoperative complications and to assess their postoperative hospital length of stay, 90-day mortality, failure to heal at 4 and 8 week follow-up visits and ability to ambulate with a prosthesis at 6 months post amputation.

Detailed Description
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This is a clinical study to test the hypothesis that Hyperbaric Oxygen (HBO2) given in the immediate postoperative period for a total of 10 treatments after Below-the-Knee Amputation (BKA) for vascular disease will reduce postoperative complications. Patients scheduled for BKA at Duke University Medical Center will be reviewed for contraindications to HBO2. Patients for whom HBO2 is not contraindicated may choose to be enrolled in the study. Patients enrolled will be randomly assigned to receive treatment or standard postoperative care. Each patient receiving treatment will receive twice daily HBO2 for 2 hours at 2 ATA. Patients receiving HBO2 will breathe 100% oxygen via head tent while inside a hyperbaric chamber at Duke University Hospital. The statistical plan for this study will test non-directional hypotheses (two-sided tests). Bonferroni correction will be used to adjust for multiple tests. The main analysis of the primary efficacy hypotheses will include data from all randomized patients in the group to which random assignment is made. Hence, the analysis will be intention to treat. This study will primarily aim to assess whether patients receiving treatment suffer fewer complications, as defined by the Vascular Quality Initiative, vs. patients who receive standard care. The Vascular Quality Initiative (VQI) is a multicenter voluntary reporting system for outcomes related to vascular surgery. The primary outcome of this study, postoperative complications, will be those outcomes meeting the definition set out in the VQI data dictionary, the set of definitions for inclusion in the VQI database. This allows for a standard definition of complications recognized by a majority of US academic medical centers. Secondary outcomes include hospital length of stay, 90-day mortality, failure to heal at 4 and 8 week follow-up visits and ability to ambulate with a prosthesis at 6 months post amputation.

Official Title
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Hyperbaric Oxygen Therapy to Prevent Complications After Lower Limb Amputation

Conditions
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Amputation; Postoperative, Sequelae

Intervention / Treatment
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* Drug: Hyperbaric Oxygen


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Able to consent Non-traumatic indication for lower limb amputation Able to receive hyperbaric oxygen therapy Exclusion Criteria: Unable to consent Contraindication to hyperbaric oxygen End stage renal disease on dialysis Current renal failure as measured by creatinine levels vs baseline change of more than 1 mg/dL and for whom dialysis is expected to be required with the next month Calciphylaxis Traumatic injuries that are the cause of the amputation Cancer being treated by chemotherapy, scheduled to be treated, or being treated or scheduled to be treated by radiation. Limb amputation secondary to ischemic complications from other operations Second amputation or reoperation on prior amputation Pregnancy

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: Permuted block
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Hyperbaric Oxygen Plus Regular Care<br>Hyperbaric oxygen (2 hours at 2 atmospheres absolute) to be administered 1-2 times daily for up to 10 treatments after amputation. Usual care for patients with amputation will be administered in parallel. | Drug: Hyperbaric Oxygen<br>* Hyperbaric oxygen (HBO2) 1-2 times daily for up to 10 times after amputation<br>* Other names: HBO2;|
| No Intervention: Regular Care<br>Usual care for patients with amputation. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Inpatient death | Mortality during the inpatient period | During inpatient stay immediately after amputation | 
| Re-operation | Unplanned return to the OR for a surgical procedure | Up to 90 days after amputation | 
| Wound infection | Any wound site infection that was culture positive or required antibiotic treatment | Up to 90 days after amputation | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Hospital length of stay | Hospital length of stay immediately after amputation | Number of days in hospital after amputation, up to approximately 30 days | 
| 90-day mortality | Death within 90 days after amputation | Up to 90 days after amputation | 
| Complete healing of amputation wound healing at 4 weeks following surgery | Complete wound healing at 4 weeks after amputation | 4 weeks after amputation | 
| Complete healing of amputation wound healing at 8 weeks following surgery | Complete wound healing at 8 weeks after amputation | 8 weeks after amputation | 
| Ambulate with prosthesis | Ability to ambulate with a prosthesis at 6 months post amputation | Up to 6 months after amputation |