Does Bicarbonate in Addition to Theophylline Reduce CIN?

Study Overview
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Brief Summary
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Contrast-induced nephropathy (CIN) is the third most frequent cause of hospital-acquired acute renal failure. Different regimes in the prophylaxis of CIN have been investigated in the last years. Recent Meta-analysis show a reduced incidence of CIN when theophylline is administered to the patients especially in patients with already existing renal impairment. Furthermore hydration with bicarbonate seems to to be superior to hydration with sodium chloride alone. The combination of the two prophylaxis has not been investigated yet. Aim of this prospective randomized trial is to investigate the effect of hydration with sodium bicarbonate compared to saline in addition to theophylline prophylaxis which all patients receive.

Official Title
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Does Bicarbonate in Addition to Theophylline Reduce Contrast Induced Nephropathy Compared to Sodium Chloride?

Conditions
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Radiographic Contrast Agent Nephropathy

Intervention / Treatment
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* Other: Hydration with bicarbonate in addition to theophylline
* Other: Hydration with sodium chloride in addition to theophylline


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Increased risk for contrast induced nephropathy defined as: Serum creatinine level ≥ 1.1 mg/dl OR Serum creatinine level ≥ 0.8 mg/dl plus an additional risk factor like diabetes mellitus, renal failure in past medical history or nephrotoxic medication (aminoglycoside, vancomycin, amphotericin B, diuretic) Exclusion Criteria: pre-existing renal replacement therapy unstable serum creatinine levels (difference of more than ±0.4 mg/dl within 3 days before contrast application) contraindications for theophylline or sodium bicarbonate (allergies, tachycardia, alkalosis, hypokalemia) additional interventions that might influence renal function

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
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Bicarbonate and theophylline<br>Hydration with bicarbonate in addition to theophylline | Other: Hydration with bicarbonate in addition to theophylline<br>* 0.154-molar sodium bicarbonate; 3 ml per kg bodyweight (maximum 330 ml) one hour before contrast exposure; additionally 200 mg theophylline as a short infusion; after contrast application hydration with another 1 ml per kg bodyweight per hour (maximum 110 ml per hour) for 6 hours<br>|
| Active Comparator: Sodium and theophylline<br>Hydration with sodium chloride in addition to theophylline | Other: Hydration with sodium chloride in addition to theophylline<br>* 0.9% sodium chloride; 3 ml per kg bodyweight (maximum 330 ml) one hour before contrast exposure; additionally 200 mg theophylline as a short infusion; after contrast application hydration with another 1 ml per kg bodyweight per hour (maximum 110 ml per hour) for 6 hours<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Contrast induced nephropathy | Raise in serum creatinine of ≥25% or ≥0.5 mg/dl | 48 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change of serum creatinine levels over time |  | 48 hours | 
| Change of creatinine clearance over time |  | 48 hours | 
| Change in blood pH |  | 48 hours | 
| Change in blood bicarbonate-concentration |  | 48 hours | 
| Change in blood sodium-concentration |  | 48 hours | 
| Change in urine pH |  | 48 hours | 
| Change in urine bicarbonate-concentration |  | 48 hours | 
| Change in urine pH sodium-concentration |  | 48 hours | 
| Incidence of patients with need for dialysis | The patients medical record was reviewed to determine whether dialysis was performed within 30 days after contrast media application. | 30 days |