Browsing by Author "ORELLANA, P"

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    EFFECTS OF EXTRACORPOREAL-CIRCULATION ON RENAL-FUNCTION IN CORONARY SURGICAL PATIENTS
    (WILLIAMS & WILKINS, 1995) LEMA, G; MENESES, G; URZUA, J; JALIL, R; CANESSA, R; MORAN, S; IRARRAZAVAL, MJ; ZALAQUETT, R; ORELLANA, P
    We prospectively studied perioperative changes of renal function in 12 previously normal patients (plasma creatinine <1.5 mg/dL) scheduled for elective coronary surgery. Glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) were measured with inulin and I-125-hippuran clearances before induction of anesthesia, before cardiopulmonary bypass (CPB), during hypo- and normothermic CPB, after sternal closure, and 1 h postoperatively. Renal and systemic vascular resistances were calculated. Urinary N-acetyl-beta-D-glucosaminidase (NAG) and plasma and urine electrolytes were measured, and free water, osmolal, and (creatinine clearances, and fractional excretion of sodium and potassium were calculated before and after surgery. I-125-hippuran clearance was lower than normal in all patients before surgery. During hypothermic CPB, ERPF increased significantly (from 261 +/- 107 to 413 +/- 261 mL/min) and returned toward baseline values during normothermia. GFR was normal before and after surgery and decreased nonsignificantly during CPB. Filtration fraction was above normal before surgery and decreased significantly during CPB (038 +/- 0.09 to 0.18 +/- 0.06). Renal vascular resistance (RVR) was high before surgery and further increased after sternotomy (from 18,086 +/- 6849 to 30,070 +/- 24,427 dynes . s . cm(-5)), decreasing during CPB to 13,9647 +/- 14,662 dynes . s . cm(-5). Urine NAG, creatinine, and free water clearances were normal in all patients both pre- and postoperatively. Osmolal clearance and fractional excretion of sodium increased postoperatively from 1.54 +/- 0.06 to 12.47 +/- 11.37 mL/min, and from 0.44 +/- 0.3 to 6.07 +/- 6.27, respectively. We conclude that renal function does not seem to be adversely affected by CPB. Significant functional alterations, such as decreased ERPF and increased RVR, were found before and during surgery, preceding CPB. These periods could contribute to postoperative renal dysfunction.
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    USE OF RADIONUCLIDE RENAL IMAGING FOR CLINICAL FOLLOW-UP AFTER EXTRACORPOREAL SHOCK-WAVE LITHOTRIPSY OF RENAL STONES
    (1992) MICHAELS, EK; PAVEL, DG; ORELLANA, P; MONTES, A; OLEA, E
    Patients treated by extracorporeal shock wave lithotripsy (ESWL) are usually evaluated by excretory urography within 1 month after treatment to determine the clearance of stone debris and rule out asymptomatic obstruction. In an attempt to obtain more precise functional information, we used technetium-99m-diethylenetriaminepentaacetic acid and iodine-131-hippurate radionuclide renal imaging studies, and a plain abdominal radiograph as the initial followup study after ESWL of 64 kidneys in 55 patients. Of 53 kidneys studied within 60 days after ESWL 42 had abnormal radionuclide renal imaging studies demonstrating pelviocaliceal stasis, excretory delay or poor function, 8 of which required subsequent interventions for obstructing stone debris. Five patients had excretory delay after ESWL that was unexpected based on a pre-ESWL excretory urogram showing normal function without dilatation. A subset of 23 patients with large stone burden or anatomical deformity from a prior operation had baseline radionuclide renal imaging studies before ESWL; function improved in 4 and worsened in 5 by radionuclide renal imaging studies after completion of treatment. A total of 19 patients had radionuclide renal imaging studies earlier (within 17 days) after ESWL because of poor function and/or large stone burden, and as expected they had evidence of obstruction from stone debris, which necessitated further followup. Our experience suggests that followup of ESWL by radionuclide renal imaging studies provides specific functional information that is of particular value in the management of patients with obstructing stone debris and/or diminished renal function. Radionuclide renal imaging studies may also reveal unsuspected obstruction or functional impairment after ESWL of uncomplicated stones, and is recommended as routine followup after ESWL.