Prevention of renal insufficiency after abdominal aortic aneurysm resection by optimal volume loading

Risk Factors and Management for Biliary Complications Following Adult Living-Donor Liver Transplantation

BACKGROUND Biliary complications (BCs) following liver transplantation are very serious. Nevertheless, it is still uncertain which components influence the incidence of BCs the most. MATERIAL AND METHODS A consecutive sample of 74 adult recipients who underwent living-donor liver transplantation were enrolled in this study. BCs that were Clavien-Dindo classification grade II or higher were determined as BCs. RESULTS There were 11 out of the 74 recipients who experienced BCs. There were no differences in preoperative background factors between the BCs+ and BCs- group. Unexpectedly, the number of bile duct orifices did not contribute to the BCs (p=0.722). In comparison with the BCs- group, the frequency of post-operative bleeding requiring re-operation was relatively higher (27.3% vs. 7.9%, p=0.0913) and this complication was the only independent risk factor (p=0.0238) for the onset of BCs. Many of the BCs+ recipients were completely treated by endoscopic or radiological intervention (81.8%). However, surgical revision was required for 2 recipients (18.2%). CONCLUSIONS Given these results, it is reasonable to believe that definite hemostasis is required to prevent future BCs. In addition, bile duct multiplicity was not associated with BCs.

Risk Factors and Management for Biliary Complications Following Adult Living-Donor Liver Transplantation

BACKGROUND Biliary complications (BCs) following liver transplantation are very serious. Nevertheless, it is still uncertain which components influence the incidence of BCs the most. MATERIAL AND METHODS A consecutive sample of 74 adult recipients who underwent living-donor liver transplantation were enrolled in this study. BCs that were Clavien-Dindo classification grade II or higher were determined as BCs. RESULTS There were 11 out of the 74 recipients who experienced BCs. There were no differences in preoperative background factors between the BCs+ and BCs- group. Unexpectedly, the number of bile duct orifices did not contribute to the BCs (p=0.722). In comparison with the BCs- group, the frequency of post-operative bleeding requiring re-operation was relatively higher (27.3% vs. 7.9%, p=0.0913) and this complication was the only independent risk factor (p=0.0238) for the onset of BCs. Many of the BCs+ recipients were completely treated by endoscopic or radiological intervention (81.8%). However, surgical revision was required for 2 recipients (18.2%). CONCLUSIONS Given these results, it is reasonable to believe that definite hemostasis is required to prevent future BCs. In addition, bile duct multiplicity was not associated with BCs.

Management of Thoracic Aneurysm

A review of the literature on the management of thoracic aneurysm is presented. These patients have various comorbid conditions and need thorough work-ups. Aneurysms can be classified according to shapes and locations. Various methods to maintain hemodynamic stability with adequate endorgan perfusion are presented. The success of the operation depends upon preoperative anticipation and preparation for adequate organ perfusion and hemodynamic stability along with good communication between the anesthesiologist and the surgical team.

Renal ischemia: does sex matter?

Renal ischemia is a common complication in the perioperative period that leads to a high rate of morbidity and mortality. As in other forms of ischemia (i.e., cardiac, neurologic), the incidence and outcome of renal ischemia is strikingly sex-specific. Sexual dimorphism in response to renal injury has been noted for many years, but is now the subject of both clinical and experimental research. Clinically, women experience a lower incidence of perioperative acute renal failure, with the exception of cardiac surgery. Experimental science is now producing tantalizing clues that sex steroids, both male and female, play a role in the kidney's response to ischemia. In this review, we evaluated sex differences in perioperative renal failure and in the pathophysiology of renal ischemia/reperfusion injury. Although much work remains to characterize the biological mechanisms involved, the data are sufficient to support consideration of gender and the use of medications that impact steroid availability in the perioperative plan of care.

Randomized clinical trial comparing the effects on renal function of hydroxyethyl starch or gelatine during aortic aneurysm surgery

Background

The optimal colloid for renal protection during abdominal aortic aneurysm (AAA) surgery is not known. This study compared the effects of two hydroxyethyl starch (HES) solutions and gelatine on perioperative renal function.

Methods

Sixty-two patients undergoing AAA surgery were randomized to 6 per cent HES of molecular weight 200/0·62 kDa or 130/0·4 kDa, or 4 per cent gelatine for plasma expansion. Measurements were taken of serum urea and creatinine to mark glomerular filtration, urinary immunoglobulin G : creatinine ratio to mark glomerular membrane function and α1-microglobulin : creatinine ratio to mark tubular dysfunction before, and for 5 days after, surgery.

Results

Serum urea was lower in both HES groups than the gelatine group. Serum creatinine was lower with HES 130/0·4 compared with gelatine at days 1, 2 and 5 after surgery (P = 0·020, P = 0·045 and P = 0·045 respectively). Urinary α1-microglobulin : creatinine ratio was lower with HES 200/0·62 compared with gelatine at 4 and 8 h (P < 0·050) and lower with HES 130/0·4 compared with gelatine at 4 to 24 h, and on days 4 and 5 (P < 0·050). Urinary immunoglobulin G : creatinine was lower in both HES groups compared with gelatine. There was no difference between the two starch groups.

Conclusion

Compared with gelatine, volume expansion with both types of HES during AAA surgery improved renal function and reduced renal injury.

Preoperative intravenous hydration confers renoprotection in patients with chronic kidney disease undergoing cardiac surgery

Patients with chronic kidney disease (CKD) are at risk to develop acute renal failure (ARF) after open heart surgery. This complication is associated with high morbidity, mortality, and cost. Because the ability to concentrate urine is lost early in the progression of CKD, renal patients kept on fluid restriction prior to surgery may develop severe dehydration, a situation consistently found to be one of the most critical risk factors for postoperative ARF. Our goal was to investigate whether intravenous hydration for 12 h prior to cardiac surgery could prevent acute renal injury in patients with CKD. This is a prospective study in a tertiary cardiac surgery center. Forty-five patients admitted for elective open heart surgery with moderate-to-severe CKD, as evidenced by a quantified glomerular filtration rate less than 45 mL/min, were assigned using a 2/1 randomization process, to either receive an intravenous infusion of half-isotonic saline (1 mL/kg/h) for 12 h before the operation (hydration group, n = 30, 29 men, 64 + 1.7 years old), or to be simply kept on fluid restriction (control group, n = 15, 14 men, 64.2 + 2.8 years old). Groups were not different in clinical and intraoperative variables associated with postoperative renal injury. ARF developed in 8 of 15 (53%) patients in the control group, but in only 9 of the 30 (30%) patients in the hydration group. Four patients in the control group (27%), but no one in the hydration group, required dialysis after the operation (P < 0.01). Peak creatinine and blood urea nitrogen values were two to three times higher in the control group than in the hydration group. Preoperative intravenous hydration may ameliorate renal damage in patients with moderate-to-severe renal insufficiency undergoing cardiac surgery.

A Comparison of Fenoldopam with Dopamine and Sodium Nitroprusside in Patients Undergoing Cross-Clamping of the Abdominal Aorta

Fenoldopam, a selective dopamine-1-receptor agonist, decreases arterial blood pressure rapidly, with a brief duration of action similar to sodium nitroprusside (SNP), but in contrast to SNP, it increases renal blood flow. We compared the hemodynamic and renal effects of fenoldopam in patients undergoing abdominal aortic surgery requiring cross-clamping of the aorta with another therapeutic option, dopamine and SNP. Fenoldopam or 2 mcg x kg(-1) x min(-1) of dopamine and SNP was infused before incision in 60 randomly selected patients in a double-blind fashion. Hemodynamic variables were recorded before incision, immediately before clamping the aorta, 5 min after cross-clamp release and upon completion of surgery. Urine output, serum creatinine, and creatinine clearance were measured intraoperatively and postoperatively. Characteristics were compared between groups using two-sample rank sum test for continuous variables and Fisher's exact test for discrete variables. The occurrence of severe hypotension, maximum systolic blood pressure, and need for additional antihypertensive drugs were not different between the groups. Most intraoperative hemodynamic variables and all indices of renal function did not differ according to treatment. Therefore, fenoldopam has no therapeutic advantage compared with similar therapies in patients undergoing major vascular surgery involving cross-clamping of the aorta.

Renal protection strategies in the perioperative period

The development of acute renal failure (ARF) in the perioperative period continues to be a vexing condition associated with high morbidity and mortality rates which have been unchanged for several decades. In this article I briefly review recent research categorizing pathogenesis of ARF and mechanisms of recovery. Once ARF is established, its maintenance phase is dependent on several mechanisms that interact with cellular integrity. The main focus of the article is on assessing clinical and experimental interventions to prevent ARF. Unfortunately, existing pharmacological and other interventions show a rather limited efficacy in preventing ARF.

Practice parameters for hemodynamic support of sepsis in adult patients: 2004 update

OBJECTIVE

To provide the American College of Critical Care Medicine with updated guidelines for hemodynamic support of adult patients with sepsis.

DATA SOURCE

Publications relevant to hemodynamic support of septic patients were obtained from the medical literature, supplemented by the expertise and experience of members of an international task force convened from the membership of the Society of Critical Care Medicine.

STUDY SELECTION

Both human studies and relevant animal studies were considered.

DATA SYNTHESIS

The experts articles reviewed the literature and classified the strength of evidence of human studies according to study design and scientific value. Recommendations were drafted and graded levels based on an evidence-based rating system described in the text. The recommendations were debated, and the task force chairman modified the document until <10% of the experts disagreed with the recommendations.

CONCLUSIONS

An organized approach to the hemodynamic support of sepsis was formulated. The fundamental principle is that clinicians using hemodynamic therapies should define specific goals and end points, titrate therapies to those end points, and evaluate the results of their interventions on an ongoing basis by monitoring a combination of variables of global and regional perfusion. Using this approach, specific recommendations for fluid resuscitation, vasopressor therapy, and inotropic therapy of septic in adult patients were promulgated.

Impact of perioperative haemodynamic monitoring on cardiac morbidity after major vascular surgery in low risk patients. A randomised pilot trial

OBJECTIVE

to evaluate whether perioperative haemodynamic optimisation influences outcome from infrarenal abdominal aortic aneurysm repair.

METHODS

a consecutive series of 100 eligible patients were randomised to either haemodynamic optimisation through the use of a pulmonary artery catheter (CI > 3.0 l/min/sqm, PWP > 10 and <18 mmHg, SVR <1450 dyne/sec/cm(-5), DO(2)> 600 ml/min/sqm) or conventional treatment.

RESULTS

there were no differences in terms of in-hospital mortality, cardiovascular morbidity, postoperative renal failure or duration of hospital stay between the groups.

CONCLUSIONS

in this study perioperative haemodynamic optimisation was not beneficial.

Intraoperative management of renal function in the surgical patient at risk. Focus on aortic surgery

Although the search for effective methods of renal prophylaxis during aortic surgery spans many decades, definitive answers are scarce. The literature is voluminous, yet the amount of work clearly relevant to the specific clinical situation of perioperative prophylaxis is small. Given the significant morbidity and subsequent mortality involved with perioperative ARF, it is difficult to sit back and do nothing when pharmacologic agents empirically are believed to possibly benefit the patient. Care must be taken to apply data from different clinical scenarios in the literature to the situation at hand. Drugs felt to be innocuous, even in low doses, may be insidiously counterproductive or damaging if they are not managed properly. Maintaining an adequate preload and stable hemodynamics seems to be the most logical universal approach at this time. Furosemide treatment without maintaining an adequate volume status once diuresis commences may be detrimental, which is true with the diuretic effects induced by mannitol or dopamine. The tachycardia resulting from a relative hypovolemia and from the beta effects of dopamine can cause myocardial ischemia from increased oxygen demand. Low urine output does not portend a negative outcome in the face of an adequate intravascular volume any more than an induced diuresis prevents renal injury. Currently, minimization of renal ischemia and maintenance of an adequate intravascular volume and renal hemodynamics are the keys to optimizing renal outcome during aortic surgery. Other maneuvers are not definitive and should be cautiously undertaken.

Pathophysiology and management of renal insufficiency in the perioperative and critically ill patient

Acute renal failure remains a common, devastating complication of the postoperative period and in the critically ill patient. The most common cause is the progression of prerenal insufficiency to ATN. Despite improved understanding of the pathogenic mechanisms, including impaired hemodynamic autoregulation, medullary hypoxia, and proximal tubular obstruction and transtubular backleak, the treatment, to date, remains largely supportive. Avoidance by ensuring hemodynamic stability, with provision of adequate renal perfusion, provides the best means for minimizing the complications of this organ dysfunction.

Effect of intra-aortic magnesium on renal function during and after abdominal aortic surgery: a pilot study

BACKGROUND

Infrarenal aortic cross-clamping causes renal vasoconstriction. Magnesium may protect against renal deterioration through its vasodilatory properties.

METHODS

Thirty patients with normal preoperative renal function undergoing infrarenal aortic cross-clamping for elective aortic surgery received magnesium (4 mmol) or saline into the aorta immediately after aortic cross-clamping and again just before unclamping in a double-blind fashion. Pulmonary artery occlusion pressure was maintained 215 mmHg. Five patients with magnesium were excluded due to need for intravenous nitroglycerine because of myocardial ischaemia during the study.

RESULTS

Postoperative creatinine clearance remained unchanged in both groups. Urinary N-acetyl-beta-D-glucosaminidase excretion increased before and decreased after aortic cross-clamping in both groups. The concentrations of glutathione peroxidase in serum were identical between the two groups.

CONCLUSIONS

These data indicate that intra-aortic magnesium had no effect on renal function during or after aortic cross-clamping.

Intraoperative fluid management--what and how much?

An approach to intraoperative fluid management based on a monitored physiologic application of the Starling principles of cardiac function is recommended to individualize therapy to optimize hemodynamic function and tissue perfusion. The complexity of intraoperative fluid administration, beginning with preoperative cardiovascular function followed by innumerable intraoperative considerations, including anesthetic pharmacology, positive pressure ventilation, operative site, and surgical technique may lead to serious intraoperative and postoperative complications. Emphasis must be given to intraoperative fluid shifts resulting in hidden fluid loss and intravascular hypovolemia that must be replaced. Explanations for this fluid redistribution have included tissue trauma, endotoxemia, and proinflammatory cytokines with resultant increased capillary permeability.

Ibuprofen does not impair renal function in patients undergoing infrarenal aortic surgery with epidural anaesthesia

OBJECTIVE

To investigate the effect of preoperative ibuprofen administration on renal function during and after infrarenal aortic surgery under thoracolumbar epidural anaesthesia (EPA).

DESIGN

A prospective randomised, double-blinded clinical study.

SETTING

Operation room and intensive care unit in a university hospital.

PATIENTS

Twenty-six consecutive patients scheduled for elective infrarenal aortic surgery.

INTERVENTIONS

The patients were prospectively randomised to receive 400 mg ibuprofen intravenously (i.v.) or a placebo aliquot before surgery.

MEASUREMENTS AND RESULTS

We assessed renal function by calculating creatinine clearance, and fractional sodium excretion before surgery (baseline), 1 h after cross-clamping (intraoperative), 6 h after cross-clamping (postoperative) and 24 h after cross-clamping (on the 1 st postoperative day). At each point in time, we additionally registered haemodynamics and determined the plasma concentration of 6-keto-PGF1alpha (stable metabolite of prostacyclin, PGI2), bicyclic PGE2 (stable metabolite of PGE1 E2), active renin, aldosterone and vasopressin by radioimmunoassays. Throughout the observation period the renal function parameters mostly remained within the normal range without a significant difference between ibuprofen- and placebo-treated patients (creatinine clearance: baseline 41 +/- 3 vs 38 +/- 6, intraoperative 57 +/- 8 vs 64 +/- 11, postoperative 64 +/- 9 vs 56 +/- 9, first postoperative day 43 +/- 5 vs 47 +/- 6 ml x min x m(-2), means +/- SEM). The plasma levels of 6-keto-PGF1alpha (68 +/- 8 vs 380 +/- 71* ng x l(-1)), bicyclic PGE2 (57 +/- 5 vs 88 +/- 9* ng x l(-1)) and vasopressin (14 +/- 7 vs 45 +/- 10* ng x l(-1), p < 0.0125), however, were significantly higher during the intraoperative period in the placebo-treated patients.

CONCLUSION

The inhibition of endogenous prostaglandin release by ibuprofen does not substantially impair renal function during infrarenal aortic surgery under EPA.

Preoperative intensive care unit admission and hemodynamic monitoring in patients scheduled for major elective noncardiac surgery: a retrospective review of 95 patients

OBJECTIVE

To review experience with preoperative intensive care unit (ICU) admission and hemodynamic monitoring to determine which patients benefited and how.

DESIGN

Retrospective review over 32-month period (1991 to 1994).

SETTING

Surgical ICU of a university teaching hospital.

PARTICIPANTS

Ninety-five patients admitted to the surgical ICU before a major elective noncardiac, nonthoracic surgical procedure.

INTERVENTIONS

All patients underwent hemodynamic monitoring with a pulmonary artery catheter (PAC). Interventions were made at the discretion of the ICU attending and attending surgeon, based on a general algorithm. Patients were categorized based on history or hemodynamics. The historic classification was as follows: group I, patients with cardiac disease documented by history and cardiac imaging, n = 37; group II, patients with cardiac disease documented by history, but not cardiac imaging, n = 24; group III, patients without documented cardiac disease, but with other significant medical problems, n = 34. Hemodynamic classification considered patients to have subnormal parameters if the cardiac index was < 2.5 L/min/m2, the mixed venous oxygen saturation was < 65%, or the oxygen delivery index was < 350 mL/min/m2 (n = 45), and normal parameters if greater than these (n = 50).

MAIN RESULTS

There were no differences in APACHE II scores. Group I patients had greater Goldman Cardiac Risk Indices than group III patients (7.4 +/- 4.8 v 5.0 +/- 3.0). Patients in group I had a significantly greater incidence of subnormal initial hemodynamic values (63%) than patients in group II (47%) or group III (32%). The incidence of postoperative cardiovascular complications among groups was not different. Fifty patients (52%) had normal hemodynamics initially; two (4%) developed postoperative cardiovascular complications compared with 10 patients (22%) of the 45 with subnormal initial hemodynamic values. Of these 45 patients, 24 (52%) had their hemodynamic parameters corrected preoperatively with crystalloids, packed red blood cells, inotropes, and/or afterload reduction. Two of these 24 patients (8%) experienced postoperative cardiovascular complications, compared with 8 of the remaining 21 patients who had no attempt to normalize their hemodynamic values preoperatively other than maintaining a normal pulmonary artery occlusion pressure.

CONCLUSIONS

Patients who had normal initial preoperative hemodynamic parameters or abnormal initial parameters that were normalized preoperatively experienced significantly fewer perioperative cardiovascular complications than those with abnormal initial values that were not normalized preoperatively. These results suggest that there may be benefit to the practice of preoperative ICU admission, hemodynamic monitoring with a PAC, and "optimization" of cardiac function in selected patients undergoing major elective noncardiac surgery. Further studies are needed to better delineate the most appropriate patient populations and effective therapeutic protocol.

A prospective randomized trial of preoperative "optimization" of cardiac function in patients undergoing elective peripheral vascular surgery

BACKGROUND

Previous investigations have suggested that preoperative invasive hemodynamic monitoring with "optimization" of cardiovascular function may favorably affect the outcome among patients undergoing peripheral vascular surgery. The purpose of this study was to evaluate the effect of preoperative optimization of hemodynamic parameters on outcome in patients undergoing aortic reconstruction (AR) or limb salvage procedures (LSP) in a randomized, prospective clinical trial.

METHODS

All 72 patients who consented to participate in this study were admitted to the intensive care unit at least 12 hours before operation for placement of a pulmonary artery catheter (PAC). Patients who were randomized to the treatment group (n = 32) were "optimized" by adjusting their hemoglobin concentration, oxygen saturation (SaO2), cardiac output, or afterload until the mixed venous O2 saturation (SvO2) was at least 65%. The control group (n = 40) underwent placement of a PAC and had oxygen transport parameters measured without any attempt to optimize SvO2.

RESULTS

There were no significant differences between the treatment and control groups with respect to age, gender, type of operation, initial Acute Physiology and Chronic Health Evaluation (APACHE) II score, SvO2, pulmonary artery occlusion pressure, or cardiac index. All treatment patients achieved an SvO2 of at least 65% before operation. Comparing the treatment and control groups, postoperative cardiovascular complications occurred in 25% versus 27%, intraoperative complications in 28% versus 20%, and death in 9% versus 5%, respectively. None of these differences was statistically significant as a whole or within the subgroups undergoing AR or LSP.

CONCLUSIONS

These data suggest that preoperative optimization of cardiovascular function by using achievement of SvO2 above 65% as the end point does not result in any reduction of intraoperative or perioperative cardiac complications in patients undergoing PVS. Further studies with alternative assessments and manipulation of different cardiopulmonary parameters may yield additional information.

Real-time monitoring of renal function during ischemic injury in the rhesus monkey

The presence of delayed graft function (DGF) following cadaver donor renal transplantation is associated with inferior graft survival as well as decreased patient survival. Delay in onset of function eliminates a valuable indicator of allograft viability, which is not easily replaced by standard diagnostic procedures. The purpose of this study was to demonstrate that a new clearance technique could be used to measure renal function minute to minute and under conditions similar to those observed in humans in the immediate posttransplantation period. A monkey model was used to provide controlled conditions. Increasing levels of ischemic injury were produced in 12 Rhesus monkeys by renal hilum cross-clamping. Real-time measurements of glomerular filtration rate (GFR) were obtained from the rate of clearance of the extracellular fluid of the GFR agent 99mTc-DTPA, as measured with a specially designed external radioactivity counting device called the ambulatory renal monitor, or ARM. GRF was measured every 2-5 min as the slope (k) of the log of activity measured minute to minute versus time. GFR measurements were correlated with blood urea nitrogen (BUN), plasma creatinine (Cr), routine light microscopy, and measurement of proliferating cell nuclear antigen (PCNA), a marker of cell proliferation. Large changes in renal function due to ischemia or ureteral obstruction were observed within minutes. In addition, the rate constant on Day 1 was predictive of peak serum Cr(R =--0.86, R2=.74, p = .0001). Acute tubular necrosis (ATN) resolution was reflected more quickly when using the rate constant (Day 1) than when using either BUN or plasma Cr (Day 3-4). Because of renal functional reserve, BUN and plasma Cr were relatively insensitive indicators of mild to moderate reductions in GFR as compared with the rate constant. We conclude that ARM is a simple method which provide an accurate, near real-time GFR readout with potential applications not only for the clinical management of patients with DGF, but also as a research tool in acute renal failure (ARF).

A randomised, clinical study of the effect of low-dose dopamine on central and renal haemodynamics in infrarenal aortic surgery

OBJECTIVE

To determine whether dopamine prevents deterioration of central haemodynamics and renal function in aortoiliac surgery.

DESIGN

Prospective, randomised and placebo-controlled.

SETTING

University hospital.

MATERIALS

Thirty patients for elective vascular surgery with implantation of an aortobifemoral or an aortobiiliac graft due to aortoiliac arteriosclerosis had infusion of dopamine 3 micrograms/kg/min or placebo during the operation and 24 h postoperatively. Thoracic epidural analgesia and general anaesthesia were used.

CHIEF OUTCOME MEASURES

Central haemodynamic measurements were registered. The effective renal plasma flow (ERPF), the glomerular filtration rate (GFR), angiotensin II, aldosterone, arginine vasopressin (AVP), atrial natriuretic peptide (ANP), endothelin and excretion of water and electrolytes were measured preoperatively, 1 h postoperatively and 24 h postoperatively.

MAIN RESULTS

During the operation the dopamine group had higher cardiac index and heart rate together with lower pulmonary artery wedge blood pressure. ERPF and GFR did not differ between the groups. In the dopamine group ERPF was increased in all patients at the first postoperative clearance. The fractional excretion of sodium, the per- and postoperative diuresis and AVP were increased in the dopamine group as compared to the placebo group. Postoperatively, ANP in the placebo group was raised as compared to the preoperative level.

CONCLUSIONS

Peroperatively, dopamine counteracted depression of left ventricular function. The increased ERPF at the first postoperative clearance in the dopamine group indicates either improved peroperative haemodynamics or a synergistic effect between dopamine and epidural sympathetic blockade. Dopamine also improved diuresis and natriuresis.

Anesthesia and ventilation for the uremic child

This article reviews the management of the uremic child from the perspective of an anesthesiologist and cardiopulmonary clinician. The acute stresses of anesthesia, surgery, and mechanical ventilation mandate a systematic, functional approach to addressing rapidly progressing complications that may occur in these patients. Chronic renal failure may be the result of many different renal diseases, but most share common implications during anesthesia. Furthermore, anesthesia can be associated with acutely decreased function of both normal and diseased kidneys.

Preoperative optimization of cardiovascular hemodynamics improves outcome in peripheral vascular surgery. A prospective, randomized clinical trial

The hypothesis that optimizing hemodynamics using pulmonary artery (PA) catheter (preoperative 'tune-up') would improve outcome in patients undergoing limb-salvage arterial surgery was tested. Eighty-nine patients were randomized to preoperative tune-up either in the surgical intensive care unit (SICU) (group 1) or the preinduction room (group 2) or to control (group 3). The tune-up consisted of fluid loading, afterload reduction, and/or inotropic support to achieve predetermined endpoints. Patients with a PA catheter had significantly fewer adverse intraoperative events (p less than 0.05), less postoperative cardiac morbidity (p less than 0.05), and less early graft thrombosis (p less than 0.05) than the control group. The overall study mortality rate was 3.4%, with a mortality rate of 9.5% in the control group and 1.5% in the PA catheter groups. There were no differences in ICU length of stay (LOS), hospital LOS, or total hospital costs, although the percentage of cost from complications was higher in group 3 (p greater than 0.05). In this group of patients, preoperative cardiac assessment and optimization is associated with improved outcome.

Renal failure after operation for abdominal aortic aneurysm

Among 656 patients undergoing surgery for abdominal aortic aneurysm, 81 patients (12%) developed postoperative renal failure. Before operation hypotension and shock occurred in 88% of the patients with ruptured aneurysm, whereas none of the patients operated electively were hypotensive. Dialysis was performed in 32 patients, while the remaining 49 patients were managed without dialysis. Within 30 days after the operation 47 patients (58%) had died. There was no difference in mortality between patients in dialysis and patients managed without dialysis. Thirteen patients died during follow-up. In six cases the death was caused by renal failure only or in combination with failure of other organs. Analysis of the cumulative survival shows that, if the patients survive the postoperative period, their life expectancy is comparable to that of patients without renal complications.

Comparison of creatinine and inulin clearances in multiple trauma

Creatinine clearance (Ccr) is a good predictor of renal dysfunction. However, numerous analytical interferences have been observed with the classical measurement of creatinine by Jaffé's procedure. This prospective study was conducted to compare 4 methods for determining creatinine; and also endogenous creatinine clearance with inulin clearance (Cin) to estimate the glomerular filtration rate. The 4 different techniques for measuring creatinine were: 1) 2 techniques using Jaffé's colorimetric reaction: one with rapid and the other with slow kinetics: 2) 2 more selective methods: enzymatic procedure and high performance liquid chromatography (HPLC). Measurements were performed in 13 multiple trauma patients after stabilization and in 5 comatose patients (control group) over a 3-day period, with strict 24-h urine collection. On the second day, inulin clearance and para-aminohippuric acid clearance (Cpah) were measured. Measurement of creatinine by Jaffé's procedure yields significantly higher levels than those obtained by the other methods. Higher levels of both plasma and urinary creatinine were observed in the multiple trauma patients with all the methods used. There were no significant differences in Ccr, Cin, Cpah between the multiple trauma patients and the control patients. The best correlations between inulin clearance and creatinine clearance were observed for Jaffé's rapid kinetics (r = 0.90) in the control group and for the enzymatic procedure in the multiple trauma group (r = 0.55). Plasma creatinine is not a useful indicator in multiple trauma. The correlation between creatinine clearance and inulin clearance is not very strong in multiple trauma, indicating that the relative evolution (not the absolute values) of creatinine clearance is of interest.

Intraoperative management of abdominal aortic aneurysms. The anesthesiologist's viewpoint

Factors that influence the choice of anesthetic, monitoring methods, and fluid management for aneurysm repair are reviewed, with particular attention to epidural anesthesia and analgesia and the pulmonary artery catheter. Management of bleeding, renal preservation, temperature control, and myocardial ischemia are discussed, and special anesthetic issues associated with ruptured aneurysms and juxtarenal and suprarenal surgery are summarized.

Abnormal pre-operative creatinine levels and renal failure following abdominal aortic aneurysm repair

Renal failure is a well-documented complication of abdominal aortic aneurysm surgery. This study examined the use of pre-operative creatinine levels as a predictor of the development of acute postoperative renal failure. There was a statistically significant association between raised pre-operative creatinine levels and the subsequent development of acute renal failure (P less than 0.05). The results of this study demonstrate the need for particular attention to be diverted to the protection of renal function in patients with pre-operative raised creatinine levels.