Early increase of procalcitonin after cardiovascular surgery in patients with postoperative complications

OBJECTIVE: Type and frequency of postoperative abnormalities were registered after cardiovascular surgery to evaluate the aetiology and diagnostic value of increased concentrations of procalcitonin (PCT) and C-reactive protein (CRP) during the early postoperative period. DESIGN: Prospective, observational study. PATIENTS: Two hundred and eight patients undergoing coronary artery bypass grafting or valve replacement requiring cardiopulmonary bypass were monitored for 7 days postoperatively for various types of infectious or non-infectious complications. Plasma PCT and CRP levels were measured on day 1 and day 2 after surgery and, when increased, until day 7. RESULTS: More patients with PCT above 2 ng/ml on day 1 or 2 (n=55) had postoperative abnormalities (95%) than patients with lower PCT (59%). Specifically, the incidence of three or more criteria of the "systemic inflammatory response syndrome" was 45% versus 4% (area under the curve of the receiver operating characteristic 0.866); positive inotropic support was needed in 65% versus 9% (0.870); respiratory insufficiency (PaO(2)/FIO(2)<200) 38% versus 12% (0.704); proven and suspected bacterial infection 9% versus 1% (0.900) and 24% versus 1% (0.897), respectively. For CRP, the respective areas under the curve were all below 0.63, while all patients had elevated CRP levels, whether they had a complication or not. CONCLUSIONS: Elevated PCT, but not CRP, correlates with evidence of systemic inflammation and other complications early postoperatively after cardiac surgery. Although the PCT levels do not rise as quickly as the criteria of the systemic inflammatory response syndrome appear, they do reflect systemic inflammation. Early identification and quantification of a systemic inflammatory response may help reduce postoperative complications.     

Exhaled nitrite/nitrate levels as a marker of respiratory complications after heart valve surgery

Purpose

The purposes of this study are to measure the nitric oxide metabolites nitrite and nitrate (NOx) in the exhaled breath condensates (EBCs) of patients submitted to heart valve surgery and to assess the correlation between NOx levels and postoperative respiratory complications.

Materials and Methods

Exhaled breath condensate and blood samples were collected from each patient during spontaneous breathing preoperatively, during invasive mechanical ventilation in the fourth hour after surgery and 12, 24, 48, and 72 hours after the operation. Nitrite and nitrate levels in the EBC and serum were measured by chemiluminescence.

Results

Thirty-two patients were included in the study. In patients who presented with postoperative respiratory complications, the postoperative levels of NOx were significantly higher in the EBC from the fourth postoperative hour compared with those who experienced uneventful postoperative periods (P = .027). However, the preoperative and postoperative serum levels of NOx were not significantly different in between-group analyses (P = .995).

Conclusion

Our results suggest that the postoperative NOx level in the EBC is an early marker of respiratory complications after heart valve surgery. Additional studies using large cohorts are necessary to corroborate our results and to better define the clinical usefulness of assessing NOx in the EBC after cardiac surgery.     

Low levels of urinary albumin excretion are associated with cardiovascular risk factors in the general population.

Microalbuminuria is associated with both an increased prevalence of cardiovascular risk factors and greater renal and cardiovascular morbidity. We questioned whether in the general population such associations can be found at lower levels of urinary albumin excretion than that of classically defined microalbuminuria. To that purpose urinary albumin concentration was measured in 40619 subjects aged 28 to 75 years. The subjects filled in a questionnaire on cardiovascular risk factors and events and were divided in deciles according to their urinary albumin concentration. Smoking was associated with albuminuria in the fifth or higher decile of urinary albumin concentration, that is with an albumin concentration of 5.1 mg/l and higher. The lower cut-off point for a positive association with hypertension was 8.8 mg/l, and for diabetes 11.2 mg/l. Family history for cardiovascular disease and hyperlipidaemia were not associated with albuminuria. We conclude that urinary albumin concentrations far below the microalbuminuric range are associated with increased prevalence of established cardiovascular risk factors. Family history for cardiovascular disease and hyperlipidaemia seems to behave differently. These data emphasize the need for more studies on the impact of albuminuria on the prediction of cardiovascular and renal disease in the general population.     

Small increases in the urinary excretion of glutathione S-transferase A1 and P1 after cardiac surgery are not associated with clinically relevant renal injury

Objective: Cardiac surgery is an important risk factor for the development of acute renal failure. Cytosolic enzymes glutathione S-transferase (GST) A1 and P1 are present selectively in proximal and distal tubular cells, respectively. We determined the extent and site of tubular injury and examined if GST excretion may predict a clinically relevant change in renal function. Design and setting: A prospective, observational study in 84 consecutive patients in the cardiac surgery intensive care unit of the University Medical Centre Nijmegen. Measurements and results: Urinary GST enzyme excretion was determined 0–4 h and 20–24 h after cardiac surgery by enzyme-linked immunosorbent assay. Data are expressed as median and 5–95% range. Urinary excretion of GSTA1 was increased: 1.25 g/mmol [0.31–10.20] creatinine at t =0–4 h ( p <0.0001, compared with controls; 0.25 [0.1–0.8]) and returned to normal values at t =20–24 h. Excretion of GSTP1 was 2.11 g/mmol [0.52–17.82] creatinine ( p <0.0001) at t =0–4 h and remained significantly elevated: 0.84 [0.30–16.86] at t =20–24 h ( p =0.01) compared with controls (0.5 [0.2–1.1]). The ten patients with the highest urinary excretion of GSTA1 or GSTP1 did not demonstrate a different plasma creatinine level on postoperative day 3, compared with the ten patients with the lowest urinary excretion of GSTA1 or GSTP1. Conclusion : Uncomplicated cardiac surgery results in a statistically significant increase in the urinary excretion of GSTA1 and GSTP1 as compared with healthy controls, indicating proximal and distal tubular damage. However, this small increase in urinary excretion of GSTs is not associated with clinically relevant renal injury.P. Pickkers is a recipient of a Clinical Fellowship grant of the Netherlands Organisation for Scientific Research (ZonMw). J.J.A.E. and L.T.G.J.v.E. equally contributed to the writing of this paper     

Increased insulin resistance is associated with increased urinary excretion of chromium in non-diabetic, normotensive Saudi adults

The role of trivalent chromium in improving glucose tolerance is well documented. Increased urinary chromium has been reported in type 2 diabetes mellitus, but it was not clear whether this had preceded diabetes mellitus, or was caused by it. Aim was to investigate the relationship between urinary chromium and the degree of insulin resistance in non-diabetic normotensive Saudi adults. 357 healthy adults aged 18-50 years were recruited randomly in a cross-sectional study design. Anthropometric and demographic information were taken. Insulin, glucose and free fatty acids were measured in fasting blood samples. Fasting urinary chromium and creatinine were also determined. Using modified QUICKI, subjects were labeled as high insulin resistant, or low insulin resistant. High insulin resistant subjects were matched for age and sex to low insulin resistant subjects. High insulin resistant subjects had higher mean BMI (p<0.001), mean waist circumference (p<0.01), and median urinary chromium (p<0.001) compared to low insulin resistant subgroup. Higher urinary chromium in high insulin resistant subgroup indicates a renal lesion leading to chromium deficiency and possibly diabetes mellitus eventually. Chromium supplementation might help to protect against the development of diabetes mellitus in this group of high insulin resistant non-diabetic Saudi individuals.     

Plasma nitrate/nitrite and endothelin-1 in patients with liver cirrhosis

The aims of this study were to examine the plasma nitrate/nitrite (NOx; two end products of nitric oxide metabolism) and endothelin-1 (ET-1) concentrations in patients with liver cirrhosis, and to investigate whether there is a relationship between these two vasoactive parameters and the course of disease. Twenty-eight patients with liver cirrhosis (11 HBV-related, four HCV-related, four alcohol-related, and nine with idiopathic etiology) and 25 healthy subjects (controls) were included in the study. The venous plasma concentrations of NOx and ET-1 were significantly higher (P<0.01 and P<0.001) in the patients with cirrhosis than in the controls. A significant increase in ET-1 was observed in the Child B subgroup vs. Child A (P<0.05), and in the Child C subgroup vs. either subgroup A or B (P<0.05). There were no statistical differences between study subgroups (Child A-C) in the mean of NOx values. Plasma NOx and ET-1 were significantly increased in patients with ascites compared to those without ascites (P<0.05 and P<0.01). Increased nitric oxide synthesis may be a compensation mechanism against endothelial injury. The highest ET-1 levels in Child C and moderately increased ET-1 levels in Child B, and the lower increase of ET-1 levels in Child A patients suggest that plasma ET-1 increases with the progression of the disease. The fact that NOx and ET-1 levels were higher in patients with decompensated cirrhosis (patients with ascites) than in those with compensated cirrhosis (patients without ascites), and the presence of a strong correlation between ET-1, NOx, and the degree of varices, supports the suggestion that there is a relationship between NOx, ET-1, and portal hypertension. Our study demonstrates that increased ET and nitric oxide metabolism is associated with the hemodynamic alterations induced by portal hypertension.     

Transfusion of ABO-nonidentical platelets is not associated with adverse clinical outcomes in cardiovascular surgery patients

BACKGROUND: Current blood transfusion standards in Canada and the United States permit transfusion of ABO-nonidentical platelets when ABO-identical platelets are not available. This practice increases the availability of platelets, a component in chronic shortage in Ontario, Canada because of the 5-day shelf-life. The impact of transfusing ABO-nonidentical platelets on patient outcomes is unknown. STUDY DESIGN AND METHODS. A retrospective review of 1721 patients who had cardiovascular surgery between November 1989 and December 1999 and who had also received a platelet transfusion perioperatively was conducted. The impact of platelet and plasma incompatibility on clinical outcomes was analyzed. RESULTS: The analysis included 1691 patients who were divided into two groups according to the compatibility of the first platelet transfusion received: ABO-identical platelet transfusion (n = 1008) and ABO-nonidentical platelet transfusion (n = 683). The only difference in baseline characteristics between the two groups was that there were more urgent cases in the ABO-identical platelet transfusion group (p = 0.04). There were no significant differences in mortality at 30 days (10% for both groups, p = NS) or in postoperative length of stay (median, 7.0 days for both groups, p = NS). No significant differences were found with respect to the use of blood components, indices of bleeding, incidence of infection, or platelet CCIs. CONCLUSION: Transfusion of ABO-nonidentical platelets in patients undergoing cardiovascular surgery is not associated with an adverse impact on patient outcome.     

Intensive care-acquired hypernatremia after major cardiothoracic surgery is associated with increased mortality

Purpose  

Hypernatremia is common in the medical Intensive Care Unit (ICU) and has been described as an independent risk factor for mortality. Hypernatremia has not yet been studied in a collection of ICU patients after cardiothoracic surgery. Therefore, we wanted to determine the incidence of hypernatremia in a surgical ICU and its association with outcomes of critically ill surgical patients.     

Increased oxygen consumption after cardiac surgery is associated with the inflammatory response to endotoxemia

Objective The aim of this study was to determine whether the increase in post-operative oxygen consumption (VO₂) in cardiac surgery patients in related to endotoxemia and subsequent cytokine release and whether VO₂ can be used as a parameter of post-perfusion syndrome.Design Prospective study.Setting Operating room and intensive care unit of a university hospital.Patients Twenty-one consecutive male patients undergoing elective coronary artery bypass surgery without major organ dysfunction and not receiving corticosteroids.Measurements and results Plasma levels of endotoxin, tumor necrosis factor (TNF) and interleukin-6 (IL-6) were measured before, during and for 18 h after cardiac surgery. Oxygen consumption, haemodynamics, the use of IV fluids and dopamine, body temperature and the time of extubation were also measured. Measurements from patients with high VO₂ (median value of the entire group) were compared with measurements from patients with low VO₂ (2 had higher levels of circulating endotoxin (P=0.004), TNF (P=0.04) and IL-6 (P=0.009) received more IV fluids and dopamine while in the ICU, and were extubated later than patients with low VO₂. Several hours after VO₂ the patient's body temperature rose, Forward stepwise regression analysis showed that circulating endotoxin and TNF explained 50% of the variability of VO₂.Conclusions This study demonstrates that patients with high post operative oxygen comsumption after elective cardiac surgery have higher circulating levels of endotoxin, TNF and IL-6 and also have more symptoms of post-perfusion syndrome. Early detection of high VO₂ might be used as a clinical signal to improve circulation in order to meet the high oxygen demand of inflammation. In addition, continuous measurement of VO₂ provides us with a clinical parameter of inflammation in interventional studies aiming at a reduction of endotoxemia or circulating cytokines.Part of this study was supported financially by Jaussen Pharmaceutica B.V. (Tilburg, The Netherlands)     

The mortality increase in cardiac surgery patients associated with shrunken pore syndrome correlates with the eGFRcystatin C/eGFRcreatinine-ratio

Shrunken pore syndrome (SPS) is a condition in which estimated glomerular filtration rate (eGFR) based upon cystatin C is lower than eGFR based upon creatinine. It has been associated with increased mortality even in the presence of normal GFR in both a cardiac surgical population and a general population. No systematic studies of the variation in eGFR_{cystatin C}/eGFR_creatinine-ratio used for SPS diagnosis have been published. This study aims to evaluate whether early and midterm mortality following elective cardiac surgery varies with the ratio used to identify SPS. Preoperative levels of cystatin C and creatinine were analysed in 4007 patients undergoing elective coronary artery bypass grafting (CABG) and/or surgical aortic valve replacement (sAVR). The eGFR_{cystatin C}/eGFR_creatinine-ratio was calculated based on the equation pairs CKD-EPI_{cystatin C}/CKD-EPI_creatinine and CAPA/LMrev. The overall 1- and 3-year all-cause mortality was 2.9 and 6.8%, respectively. Mean follow-up time was 3.6 years. Mortality markedly and progressively increased with a decrease in the eGFR_{cystatin C}/eGFR_creatinine-ratio for both equation pairs. An increase in mortality was noted already when the ratio decreased from 1.0 to 0.90. To facilitate the clinical decisions based upon the SPS-defining eGFR_{cystatin C}/eGFR_creatinine-ratio, we calculated both the ratios defining the highest combined sensitivity and specificity and the ratios producing a high specificity of 95%, finding different cut-off for these scenarios.     

Admission hyperglycemia is associated with poor outcome after emergent coronary bypass grafting surgery

PurposeHyperglycemia during or after cardiac surgery is a common finding that is associated with poor outcome. Very few data, however, are available regarding a correlation between admission blood glucose and outcomes after coronary artery bypass grafting (CABG). Thus, the goal of the current study was to examine the relationship between admission blood glucose and outcome after emergency CABG surgery.Materials and MethodsA retrospective analysis to evaluate whether admission hyperglycemia associated with increased morbidity or mortality was performed in patients after emergency CABG surgery. The records of all the patients undergoing emergency CABG surgery between January 1999 and December 2010 at the University of Virginia Health System were reviewed. Postoperative in-hospital mortality and complications were considered as study end points.ResultsA total of 240 patients met the final inclusion criteria. Overall mortality was 14.1%. The median admission blood glucose in patients who died 7.4 (interquartile range, 5.9-10.1) mmol/L was significantly higher compared with survivors 6.1 (interquartile range, 5.4-7.2; P < .01). Furthermore, 59% of the patients who died had admission blood glucose levels higher than 6.6 mmol/L, whereas only 35% of the patients who survived had similar blood glucose levels (P = .01). On multivariable analysis, admission blood glucose was identified as an independent risk factor for death after emergency CABG (P = .01; odds ratio, 1.16; 95% confidence interval, 1.04-1.29). Admission blood glucose was further identified as independently associated with increased risk for a composite outcome of death, postoperative renal failure or stroke (P = .01; odds ratio, 1.14; 95% confidence interval, 1.03-1.27).ConclusionsOur study shows for the first time that admission blood glucose is correlated with increased morbidity and mortality among patients undergoing emergency CABG surgery.     

Bacteriuria is associated with urge urinary incontinence in older women

Objective

To investigate the association between bacteriuria and frequency and type of urinary incontinence in elderly people living in the community. Bacteriuria and urinary incontinence are common conditions and often coexisting in this population; the authors have previously reported the prevalence of bacteriuria to be 22.4% in women and 9.4% in men.

Design

Cross-sectional study.

Setting

The catchment area of a primary healthcare centre in a Swedish middle-sized town.

Subjects

Residents, except for those in nursing homes, aged 80 and over. Participation rate: 80.3% (431/537).

Main outcome measures

Urinary cultures and questionnaire data on urinary incontinence.

Results

In women the OR for having bacteriuria increased with increasing frequency of urinary incontinence; the OR was 2.83 (95% CI 1.35–5.94) for women who were incontinent daily as compared with continent women. Reporting urge urinary incontinence increased the risk of having bacteriuria: 3.36 (95% CI 1.49–7.58) in comparison with continent women while there was no significant association between stress urinary incontinence and bacteriuria. The prevalence of bacteriuria among men was too low to make any meaningful calculations about the association between bacteriuria and frequency and type of incontinence.

Conclusion

Bacteriuria is associated with more frequent leakage and predominantly with urge urinary incontinence. The causes of this association and their clinical implications remain unclear. There might be some individuals who would benefit from antibiotic treatment, but further studies are warranted.     

Macrophage migration inhibitory factor is associated with positive cultures in patients with sepsis after cardiac surgery

This prospective consecutive observational study describes the blood levels of macrophage migration inhibitory factor (MIF), other cytokines, and markers of acute-phase response in 49 consecutive patients who developed the clinical syndrome of sepsis after cardiac surgery. Before starting antimicrobial treatment, all patients underwent microbiologic screening, and blood samples were collected. These samples subsequently were assayed for MIF, macrophage chemoattractant protein-1 (MCP-1), tumor necrosis factor-alpha (TNF-alpha), interleukin (IL)-6 and -10, procalcitonin (PCT), and C-reactive protein (CRP). Patients with positive cultures (n = 25) had a higher mortality (P = 0.046) and higher levels of MIF (P < 0.001) than those with negative cultures (n = 24). We could not detect significant difference between the groups concerning the levels of CRP, PCT, IL6, IL10, MCP-1, or TNF-alpha. MIF levels showed an area under receiver operator curve of 0.823 for the prediction of culture-proven bacterial infection, with the best cut-off value at 988.5 pg/mL. In conclusion, circulating levels of MIF could be indicated as a valuable marker of microbiologically documented sepsis in patients after cardiac surgery, which suggests that MIF may be prospectively explored as a useful diagnostic tool in this setting.     

Ventilation-induced lung injury is associated with an increase in gut permeability

Mechanical ventilation is associated with several harmful effects mainly related to high tidal volumes (Vt). Ventilator-induced lung injury can be responsible for an increased production of inflammatory mediators. We evaluated remote consequences on the gut of lung triggered inflammatory response, neutralizing anti-tumor necrosis factor (TNF) antibody was administered to assess the role of TNF in lung and gut permeability changes. Rats were anesthetized and ventilated for 2 h. A control group (Con: Vt = 10 mL/kg) was compared with a high Vt group (HV: Vt = 30 ml/kg). One microCi of I125-labeled human serum albumin was injected to measure extravascular albumin space. Gut permeability was evaluated by plasma-to-lumen ratio leakage of I125 human serum albumin. Extravascular albumin space increased in the HV group from 446 +/- 50 microL to 2783 +/- 887 microL. Gut index of permeability increased from 5.1 +/- 1.2 to 14.2 +/- 4.9. Anti-TNF antibody prevented both lung and gut increase in permeability. High tidal volume ventilation resulted in an increase in lung edema and gut permeability, antagonism of TNF with neutralizing antibodies abrogated the increase in gut permeability as well as lung edema.