How Much Fluid Do We Need For Immediate Post-operative Management In Tetralogy Of Fallot

How much fluid do we need for immediate post-operative management in Tetralogy of Fallot? J Figueira MD,I Machado MD, I Tolj MD, MA Arapé MD, Nakary Moreno RN BSN Fundación De Todo Corazón Richard Gibson Hospital de Especialidades Pediátricas

Background: Cardiopulmonary Bypass (CPB) produces a systemic inflammatory response with consequences: endovascular lesion, alterated vascular permeability, with increase of fluid pass from intravascular to interstitial space. This effect increases the total body water volume in the interstitial space. Our aim is to show how in a homogenous group of patients, under CPB and Aortic XClamp (AXC) stress, by monitorizing simple hemodynamic parameters, we establish a fluid-management strategy that leads to a brief ICU stay and avoid inotropes. Methods: From 231 patients submitted to cardiac surgery, we retrospectively selected from January 2007 to August 2009, 34 cases (14.72%) diagnosed with Tetralogy of Fallot (TOF). In order to assess intravascular space status and measure inflammatory response, we selected as variables: Blood Pressure (BP), Heart Rate (HR), Central Venous Pressure (CVP), Urinary Output (UO) and Urinary Density (UD). We related them to CPB and AXC times, blood glucose (BG) and white-blood count (WBC) to admission and discharge from our Intensive Care Unit (ICU).Results: All 34 cases underwent surgery on normothermia, with minicardioplegia. Infundibular patch (18 cases), transanular patch (10 cases), infundibular and pulmonary patch (6 cases),. Management protocol includes: 2000cc/m²BSA base hydration with saline 0.45% and dextrose 5%, NSAID (Ketoprofen 2 mg/Kg). Aim was to obtain normal UD, UO, HR, BP and CVP values. Our population (data expressed: median (min-max). Age: 2.1(0.9-9) years; Weight: 11.5(7.6-27.4) Kg; Height: 82.5(63-132) cm; CPB time: 55.5(38-109) minutes; AXC time: 39(20-80)min; Extubation time: 0(0-24) hours; ICU stay: 21.5(14-100)hours. UD (pre CPB): 1020(1006-1034), UD post CPB: 1021 (1006-1035), UD on ICU admission: 1025 (1010-1036), 6 hours later 1030 (1015-1040). BG on ICU admission: 113 (103-238) mg/dl. BG on discharge: 110mg/dl (76-197) mg/dl, p=0.46. HR: 118(93-135) x´; Systolic BP: 97(63-127) mmHg; Diastolic: 58(4894) mmHg; CVP: 10(7-13) mmHg. Total fluids in 6 hours: 1422(776-2379) cc/m²BSA; Theoretical total fluids calculated per patient: 257(189-499) cc/m²BSA; UO in 6 hours: 2.1(0.4-6.6) cc/kg/h; WBC on ICU admission: 15350(3600-32500)/mm3; WBC on discharge: 12975(3700-23800)/mm3 (p=0.117). There is a 5.72 times-increase in the total fluid administration during the first 6 postoperative hours compared to the theoretical-calculated values (median=5.53, p<0.05). One patient died (1/34; 2.94%). Conclusion: On selected patients, CPB and AXC time are no important variables to consider regarding severity of the inflammatory response. It can be better observed through clinical outcome, WBC and BG. With normal renal function, UD is not relevant as an isolated parameter, but together with all the before mentioned variables, it permits to properly assess intravascular space. Adequate values of UD, UO, BP, HR and CVP, carried about a five-fold increase of total fluid administration. Early extubation, a friendly environment with parental presence and adequate analgesia, led to a satisfactory final result: short ICU stay and good clinical outcomes. The amount of suministrated fluids given as part of a simplified cardiac surgery postoperative protocol is safe for our patients and does not cause late complications. Reduced ICU stay was possible obtaining final cost reduction, important aspect to be considered, especially in costconstrained environments.