Preventing Contrast Nephropathy With Sodium Bicarbonate in Patients With Pulmonary Edema,Heart Failure,Uncontrolled HTN

Radio Contrast Induced Nephropathy (RCIN) remains a well recognized complication in patients undergoing diagnostic or interventional procedures requiring radiographic contrast agents. Recent studies have shown benefit in administering Sodium Bicarbonate over normal saline( the uniformly accepted prophylaxy) in preventing RCIN.But most studies have excluded patients with history of pulmonary edema, severe heart failure(NYHA 3-4), uncontrolled hypertension or ejection fraction less than 30%. Therefore the aim of this study is to evaluate the efficacy of sodium bicarbonate solved in half saline compared with infusion of half saline in prevention of RCIN in these groups of patients.

Radio Contrast Induced Nephropathy (RCIN) remains a well recognized complication in patients undergoing diagnostic or interventional procedures requiring radiographic contrast agents and is the third leading cause of acquired acute renal failure in hospitalized patients. Strategies for the prevention of radiocontrast nephropathy have focused on countering vasoconstriction (pre-hydration, fenoldopam, and theophylline), enhancing flow through the nephron (diuretics), or protection against oxygen-free-radical injury (urinary alkalinization and N-acetylcysteine).

Among all prophylactic measures that have been proposed, adequate preprocedural and postprocedural hydration has demonstrated effectiveness in the prevention of radiocontrast nephropathy. Thus, it remains the most frequently applied measure in clinical practice.

A Recent study in May 2004 have shown benefit in administering Sodium Bicarbonate over normal saline as a prophylaxy.Since alkalizing renal tubular fluid with bicarbonate may reduce injury .

Most studies have excluded patients with history of pulmonary edema, severe heart failure(NYHA 3-4), uncontrolled hypertension or ejection fraction less than 30% and no specific protocol is tested for this group of patients. This study focuses on preventing RCIN in this specific group of patients .

Comparisons:1075 cc NaCl 0.45% or 75 cc of sodium bicarbonate 8.4% solved in one liter of NaCl 0.45%. Each fluid is infused at the rate of 3 ml/kg/ hour one hour before the angiographic procedure, continuing at the rate of 1 ml/kg/ hour for 6 hours after the procedure. Maximum rate of fluid permitted is that for a body weight of 110 Kg.

Eligibility Criteria:
Inclusion Criteria:

* individuals aged 18 years or older with serum creatinine levels of at least 1.5 mg/dl , who were scheduled to undergo diagnostic or therapeutic coronary artery angiography.
* Patients with a history of Pulmonary edema or
* Patients with severe Heart Failure ( NYHA 3-4) or
* Patients with ejection fraction of less than 30% on Echocardiography ( done in the previous month of admission) or
* Patients with uncontrolled hypertension (treated systolic blood pressure more than 160 mmHg, or diastolic blood pressure more than 100mmHg )

Exclusion Criteria:

* serum creatinine levels of more than 8 mg/dl
* previous history of dialysis
* GFR \< 20 ( as calculated with this formula: ((140-Age)(Weight(Kg)) / Serum Creatinine(mg/dl) ×72 ) , in females GFR was multiplied by 0.85 )
* emergency catheterization
* recent exposure to radiographic contrast agents (within previous two days of the study)
* radiocontrast agent dosage needed more than 300 gr during the procedure
* allergy to radiocontrast agent
* pregnancy
* administration of dopamine, mannitol , fenoldopam or N-Acetyl Cystein during the intended time of study
* need for continuous hydration therapy (e.g. sepsis )
* history of Multiple myeloma