Forced fluid removal in intensive care patients with acute kidney injury: The randomised FFAKI feasibility trial.

BACKGROUND: Accumulation of fluids is frequent in intensive care unit (ICU) patients with acute kidney injury and may be associated with increased mortality and decreased renal recovery. We present the results of a pilot trial assessing the feasibility of forced fluid removal in ICU patients with acute kidney injury and fluid accumulation of more than 10% ideal bodyweight. METHODS: The FFAKI-trial was a pilot trial of forced fluid removal vs standard care in adult ICU patients with moderate to high risk acute kidney injury and 10% fluid accumulation. Fluid removal was done with furosemide and/or continuous renal replacement therapy aiming at net negative fluid balance > 1 mL/kg ideal body weight/hour until cumulative fluid balance calculated from ICU admission reached less than 1000 mL. RESULTS: After 20 months, we stopped the trial prematurely due to a low inclusion rate with 23 (2%) included patients out of the 1144 screened. Despite the reduced sample size, we observed a marked reduction in cumulative fluid balance 5 days after randomisation (mean difference -5814 mL, 95% CI -2063 to -9565, P = .003) with forced fluid removal compared to standard care. While the trial was underpowered for clinical endpoints, no point estimates suggested harm from forced fluid removal. CONCLUSIONS: Forced fluid removal aiming at 1 mL/kg ideal body weight/hour may be an effective treatment of fluid accumulation in ICU patients with acute kidney injury. A definitive trial using our inclusion criteria seems less feasible based on our inclusion rate of only 2%.

Should blood flow during cardiopulmonary bypass be individualized more than to body surface area?

Blood flow during cardiopulmonary bypass (CPB) is calculated on body surface area (BSA). Increasing comorbidity, age and weight of today's cardiac patients question this calculation as it may not reflect individual metabolic requirement. The hypothesis was that a measured cardiac index (CI) prior to normothermic CPB is a better estimate. A cross-over study, with random allocation to CPB blood flow for 20 minutes based on either a calculation (2.4 L/min/m(2)) or on CI, with a switch to the opposite flow for another 20 minutes, was performed. Twenty-two elective cardiac surgery patients with normal ventricular function were included. Effect parameters were cerebral oxygenation, mixed venous saturation and arterial lactate. CI varied from 1.9 to 3.1 L/min/m(2) (median 2.4 L/min/m(2)). No differences in effect parameters were seen. In conclusion, a CPB blood flow based on an individual estimate did not improve cerebral and systemic oxygenation compared to a blood flow based on BSA.

Oxygenation and release of inflammatory mediators after off-pump compared with after on-pump coronary artery bypass surgery.

BACKGROUND: In a previous study, we showed that oxygenation was impaired for up to 5 day after conventional coronary artery bypass grafting (CABG). As cardiopulmonary bypass (CPB) may have a detrimental effect on pulmonary function, we hypothesized that coronary revascularization grafting without the use of CPB (OPCAB) would affect post-operative oxygenation and release of inflammatory mediators less compared with CABG. METHODS: Low-risk patients scheduled for elective coronary revascularization were randomly assigned to one of two groups (CABG, n = 17 or OPCAB, n = 18). Two parameters of oxygenation, shunt (%) and ventilation-perfusions mismatch, described as DeltaPO(2) (kPa), were estimated for up to 5 days post-operatively. Systemic release of interleukin (IL)-6, -8 and -10, C-reactive protein (CRP) and neutrophils were measured in peripheral blood samples for up to 3 days post-operatively. The lungs participation in the cytokine response was evaluated from mixed venous blood samples taken within the first 16 h post-operatively. RESULTS: OPCAB was followed by a higher shunt (P = 0.047), with no difference (P = 0.47) in the deterioration of DeltaPO(2) between the groups. OPCAB was followed by an attenuated systemic release of IL-8 (P = 0.041) and IL-10 (P = 0.006), while the release of IL-6 (P = 0.94), CRP (P = 0.121) and neutrophils (P = 0.078) did not differ between the groups. Indications of an uptake of cytokines in the lungs were found after OPCAB. CONCLUSIONS: When comparing OPCAB with CABG, oxygenation was more affected and only part of the systemic inflammatory response was attenuated.

Oxygenation within the first 120 h following coronary artery bypass grafting. Influence of systemic hypothermia (32 degrees C) or normothermia (36 degrees C) during the cardiopulmonary bypass: a randomized clinical trial.

BACKGROUND: Lung function is often impaired after cardiac surgery performed under cardiopulmonary bypass (CPB). Normothermic CPB has become more common, but it remains unknown whether it reduces post-operative lung function compared with hypothermic CPB. The aim of this study was to investigate oxygenation within the first 120 h after systemic hypothermia and normothermia under CPB. METHODS: Thirty patients undergoing coronary artery bypass grafting (CABG) were randomized to either hypothermic (32 degrees C) or normothermic (36 degrees C) CPB. Oxygenation was studied by a simple method for the estimation of intrapulmonary shunt and ventilation-perfusion (V/Q) mismatch pre-operatively and 4, 48 and 120 h post-operatively by changing Fio2 in four to six steps. V/Q mismatch was described with DeltaPo2 (normal values, 0-2.38 kPa). RESULTS: Shunt and V/Q mismatch (DeltaPo2) increased post-operatively in both groups (P<0.01), with no differences between the groups, and with the nadir values 48 h after surgery, i.e. shunt of 15% (5.8-25%) and DeltaPo2 of 3.0 kPa (0.8-14 kPa) [values given as median (range)]. CONCLUSIONS: Impaired oxygenation is prevalent and prolonged following CABG, with equal intensity after hypothermic and normothermic CPB.

Myocardial structure as a determinant of pre- and postoperative ventricular function and long-term prognosis after valve replacement for aortic stenosis.

BACKGROUND: Long-term results after aortic value replacement for aortic stenosis can be correlated to a cardiac-related pre-operative risk profile. This predictability indicates that there is a common basis in subtle or overt structural abnormalities of left ventricular myocardium. METHODS AND RESULTS: Forty-nine patients aged 24-82 (mean 61) years, with aortic stenosis had a full wall thickness transmural biopsy of the left ventricular antero-lateral free wall during aortic valve replacement. Echocardiography and radionuclide ventriculography were performed prior to, and 18 months (n = 41) after, the operation. Postoperative follow-up to a maximum of 7.7 years was 100% complete. Pre-operatively, all patients had an increase in both the left ventricular mass index (202 +/- 67 g.m-2) and the muscle cell diameter (41 +/- 8 microns); other morphological data included a muscle cell nucleus volume of 752 +/- 192 microns3, a muscle cell mass index of 163 +/- 54.m-2, and a fibrous tissue mass index of 39 +/- 16 g.m-2. Patients with a pre-operative episode of clinical left ventricular failure (n = 19) had significantly greater morphological variables than those without. Pre-operative ejection fraction and other measures of systolic function correlated inversely with the morphological data, except for the fibrous tissue mass index; diastolic function indices correlated inversely with all the morphological variables. At the 18-month re-study, the same general picture was noted, but with an underlying strengthening, especially of the muscle cell mass index. Overall, the mass index dropped to 152 +/- 51 g.m-2 (P < 0.0001), but in 17% of the patients it became normal; the mass index at 18 months was directly correlated to morphological variables. A high muscle cell nucleus volume was identified as an independent predictor of early and late mortality. CONCLUSIONS: Abnormalities of the hypertrophied left ventricular muscle cell and the degree of muscle hypertrophy are, to some degree, underlying determinants of pre-operative symptomatology, pre- and postoperative ventricular function, and early and late mortality after valve replacement for aortic stenosis. Incomplete hypertrophy impaired results, was related to pre-operative myocardial structural abnormalities.

Impact of size mismatch and left ventricular function on performance of the St. Jude disc valve after aortic valve replacement.

BACKGROUND: The hemodynamic function of the St. Jude valve may change relative to changes in left ventricular function after aortic valve replacement for aortic stenosis. From theoretical reasons one may hypothesize that prosthetic valve hemodynamic function is related to left ventricular failure and mismatch between valve size and patient/ventricular chamber size. METHODS: Forty patients aged 24 to 82 years who survived aortic valve replacement for aortic stenosis with a standard St. Jude disc valve (mean size, 23.5 mm; range, 19 to 29 mm) were followed up prospectively with Doppler echocardiography and radionuclide left ventriculography preoperatively and 9 days, 3 months, and 18 months after the operation with assessment of intravascular hemolysis at 18 months. Follow-up to a maximum of 7.4 years (mean, 6.3 years) was 100% complete. RESULTS: Left ventricular muscle mass index decreased from 198 +/- 62 g.m-2 preoperatively to 153 +/- 53 g.m-2 at 18 months (p < 0.001), paralleled by a significant increase in left ventricular ejection fraction, peak ejection rate, and peak filling rate; only 18% of the patients had normal left ventricular muscle mass index and only 32% normal ventricular function (normal left ventricular ejection fraction, peak ejection rate, peak filling rate, early filling fraction, and late filling fraction during atrial contraction) at 18 months. Prosthetic valve peak Doppler gradient dropped from 20 +/- 6 mm Hg at 9 days to 17 +/- 5 mm Hg at 18 months (p < 0.05). Reduction of left ventricular muscle mass index was unrelated to peak gradient and size of the valve. Peak gradient at 18 months rose with valve orifice diameter of 17 mm or less (by 6 mm Hg), orifice diameter/body surface area of 9 mm.m-2 or less (by 5 mm Hg), left ventricular enddiastolic dimension (by 23 mm Hg per 10 mm increase), and impaired ventricular function (by 3 mm Hg). All but 2 patients (5%) had intravascular hemolysis; none had anemia. Two patients with moderate paravalvular leak had the highest serum lactic dehydrogenase levels; 4 patients with trivial leak had higher serum lactic dehydrogenase levels than those without leak. Serum lactic dehydrogenase levels rose with moderate paravalvular leak, impaired ventricular function, and valve orifice diameter. Six patients with trivial or moderate paravalvular leak had a cumulative 7-year freedom from bleeding and thromboembolism of 44% +/- 22% compared with 87% +/- 5% for those without leak (p < 0.05). CONCLUSIONS: The peak gradient of the St. Jude aortic valve dropped marginally over the first 18 postoperative months in association with incomplete left ventricular hypertrophy regression and marginal improvement of ventricular function. Mismatch between valve size and ventricular cavity size or patient size and impaired function of a dilated ventricle significantly compromised the performance of the St. Jude valve. Probably explained by platelet destruction or activation, paravalvular leak was related to bleeding and thromboembolic complications.

[Data and quality assurance tools from a new cardiac center in Denmark]. / Data samt kvalitetsstyringsredskab fra et nyt hjertecenter i Danmark.

Open heart surgery was established at Aalborg Hospital in 1992. In the time period March to December 1992 cardiac anaesthesia was administered in 98 operations utilizing extracorporeal circulation and cardiopulmonary bypass. Mortality in coronary artery surgery was 1.6%. All patients were prospectively registered using a new dataform allowing registration of 228 patients related variables concerning preoperative status, course of anaesthesia and perfusion, surgery and postoperative intensive care. Quality assurance in cardiac surgery requires risk factor analysis, and registration of numerous data is a necessary tool. The software for our database system has been developed and programmed using the database programme dBASE IV from the Ashton/Tate Corporation.

[Surgical treatment of hydronephrosis. Late results after surgery using the Anderson-Hynes method]. / Kirurgisk behandling af hydronefrose. Senresultatet efter operation ad modum Anderson-Hynes.

Twenty-one patients with hydronephrosis mean age 37 years (11-72) were operated using Anderson-Hynes pyeloplasty, without routine use of a nephrostomy catheter. One patient developed urinary leakage postoperatively, which ceased after insertion of a ureteric catheter. Follow-up assessment was performed after a mean observation time of 85 months (44-142). Clinical examination, laboratory investigations, urography and renography were performed preoperatively and at follow-up. No signs of stones or stenosis in the pelvis were found. The patients operated upon before the age of 30 showed improved postoperative renal function. All patients had symptoms preoperatively, but only one had symptoms postoperatively. It can be concluded that the results of surgical intervention in hydronephrosis are excellent, especially in patients below 30 years.

Postspinal headache in young and elderly patients. Two randomised, double-blind studies that compare 20- and 25-gauge needles.

In two randomised, double-blind studies of elderly patients with a mean age of 68.9 (range 21-88) years and young patients, mean age 29.4 (range 20-40) years, the effect of needle size on the incidence of postspinal headache was compared. The two needle groups, 20- and 25-gauge, were comparable in both studies with regard to number, sex, age and type of surgery. The incidence of postspinal headache in young patients was 27.6% when a 20-gauge needle was used and 12.6% with a 25-gauge needle. There was no significant difference in either the incidence of headache in the elderly patients (10.8% and 7.8%, respectively) or between the sexes. It is concluded that it does not matter if a 20- or a 25-gauge needle is used for spinal analgesia in elderly patients with regard to postspinal headache, but if spinal analgesia is indicated in young patients a fine needle is preferred.