Influence of patients’ clinical features at intensive care unit admission on performance of cell cycle arrest biomarkers in predicting acute kidney injury

Objectives

Identification of acute kidney injury (AKI) can be challenging in patients with a variety of clinical features at intensive care unit (ICU) admission, and the capacity of biomarkers in this subpopulation has been poorly studied. In our study we examined the influence that patients’ clinical features at ICU admission have over the predicting ability of the combination of urinary tissue inhibitor of metalloproteinase-2 (TIMP2) and insulin-like growth factor binding protein 7 (IGFBP7).

Methods

Urinary [TIMP2]•[IGFBP7] were measured for all patients upon admission to ICU. We calculated the receiver operating characteristics (ROC) curves for AKI prediction in the overall cohort and for subgroups of patients according to etiology of ICU admission, which included: sepsis, trauma, neurological conditions, cardiovascular diseases, respiratory diseases, and non-classifiable causes.

Results

In the overall cohort of 719 patients, 239 (33.2%) developed AKI in the first seven days. [TIMP2]•[IGFBP7] at ICU admission were significantly higher in AKI patients than in non-AKI patients. This is true not only for the overall cohort but also in the other subgroups. The area under the ROC curve (AUC) for [TIMP2]•[IGFBP7] in predicting AKI in the first seven days was 0.633 (95% CI 0.588–0.678), for the overall cohort, with sensitivity and specificity of 66.1 and 51.9% respectively. When we considered patients with combined sepsis, trauma, and respiratory disease we found a higher AUC than patients without these conditions (0.711 vs. 0.575; p=0.002).

Conclusions

The accuracy of [TIMP2]•[IGFBP7] in predicting the risk of AKI in the first seven days after ICU admission has significant variability when the reason for ICU admission is considered.

Routine Adoption of Urinary [IGFBP7]∙[TIMP-2] to Assess Acute Kidney Injury at Any Stage 12 hours After Intensive Care Unit Admission: a Prospective Cohort Study

The urinary tissue inhibitor of metalloproteinases-2 and insulin-like growth factor-binding protein 7 ([TIMP-2]∙[IGFBP7]) have been introduced to improve risk prediction of severe acute kidney injury (AKI) within 12 hours of measurement. We performed a prospective cohort study to evaluate if the predictive value of [TIMP-2]∙[IGFBP7] for AKI might continue after 12 hours. We enrolled 442 critically ill adult patients from June to December 2016. Urine samples were collected at admission for [TIMP-2]∙[IGFBP7] measurement. Baseline patient characteristics were recorded including patients' demographics, prior health history, and the main reason for admission to build a logistic regression model to predict AKI. AKI occurrence differed between patients with [TIMP-2]∙[IGFBP7] ≤0.3 and >0.3 (ng/ml)2/1000 (31.9% and 68.10% respectively; p < 0.001). Patients with AKI had higher biomarker values compared to those without AKI (0.66 (0.21-2.84) vs 0.22 (0.08-0.63) (ng/ml)2/1000; p < 0.001). [TIMP-2]∙[IGFBP7] at ICU admission had a lower performance in predicting AKI at any stage within 48 hours and 7 days after measurement (area under the receiver operating characteristic curve (AUC) equal to 0.70 (95%CI 0.65-0.76), AUC 0.68 (95%CI 0.63-0.73)). In the logistic regression model, 0.1 (ng/ml)2/1000-unit increment was likely to increase the risk of AKI by 2% (p = 0.002).

Predicting Acute Kidney Injury in Intensive Care Unit Patients: The Role of Tissue Inhibitor of Metalloproteinases-2 and Insulin-Like Growth Factor-Binding Protein-7 Biomarkers

<b><i>Background:</i></b> Acute kidney injury (AKI) diagnosis is based on a rise in serum creatinine and/or fall in urine output. It has been shown that there are patients that fulfill AKI definition but do not have AKI, and there are also patients with evidence of renal injury who do not meet any criteria for AKI. Recently the innovative and emerging proteomic technology has enabled the identification of novel biomarkers that allow improved risk stratification. <b><i>Methods:</i></b> Tissue inhibitor of metalloproteinases-2 (TIMP-2), insulin-like growth factor-binding protein 7 (IGFBP7) were measured to a cohort of 719 consecutive patients admitted to Intensive Care Unit (ICU). The primary endpoint was the evaluation of clinical performances of the biomarkers focusing on the probability do develop AKI in the first 7 days. <b><i>Results:</i></b> The Kaplan-Meier analysis considering the first 7 days of ICU stay suggested a lower risk of developing AKI (<i>p</i> &#x3c; 0.0001) for patients with a negative (&#x3c;0.3; TIMP-2*IGFBP7) test. <b><i>Conclusion:</i></b> (TIMP-2*IGFBP7) at ICU admission has a good performance in predicting AKI, especially in the first 4 days in ICU.

Airway management with Fastrach laryngeal mask versus Spritztube: a prospective randomized manikin-based study

BACKGROUND

A new promising device, the Spritztube (ST), was developed combining the ability to perform both supraglottic ventilation and orotracheal fibreoptic intubation using the same device, allowing an easy passage from supraglottic ventilation to tracheal ventilation avoiding apnea. The present study aims to compare the speed and the subjective ease of insertion of the novel tracheal tube (Spritztube®) compared to the intubating laryngeal mask airway Fastrach™ (FT-LMA) in a simulation environment.

METHODS

Each participant received verbal instruction and practical demonstration concerning "technique of insertion" for both devices on manikin and, in a randomized order, used both devices. Time of placement (T1), time of inflation (T2), the elapsed procedural time (T3), ease of insertion, time of exchange maneuver for intubation (T4), success rates and number of attempts were recorded for each EAD.

RESULTS

Forty-seven participants were enrolled. The ST was judged as easier insertion than FT-LMA (P<0.001) having also a significant higher success rate than FT-LMA (P<0.001). Number of attempts for insertion was similar. Number of attempts for exchange to ETI was significantly more for FT-LMA (P<0.001). FT-LMA was applied 11 s faster than the ST (median T3 Fastrach: 13 s, ST: 24 s, P<0.001) as the exchange maneuver for ETI (median T4 FT-LMA: 13 s, ST: 24 s, P<0.001).

CONCLUSIONS

In a manikin simulation setting, insertion and intubation with and ST was performed 11 s slower than with use of a FT-LMA.

Impact of hyperhydration on the mortality risk in critically ill patients admitted in intensive care units: comparison between bioelectrical impedance vector analysis and cumulative fluid balance recording

BACKGROUND

Studies have demonstrated a positive correlation between fluid overload (FO) and adverse outcomes in critically ill patients. The present study aims at defining the impact of hyperhydration on the Intensive Care Unit (ICU) mortality risk, comparing Bioelectrical Impedance Vector Analysis (BIVA) assessment with cumulative fluid balance (CFB) recording.

METHODS

We performed a prospective, dual-centre, clinician-blinded, observational study of consecutive patients admitted to ICU with an expected length of ICU stay of at least 72 hours. During observational period (72-120 hours), CFB was recorded and cumulative FO was calculated. At the admission and daily during the observational period, BIVA was performed. We considered FO between 5% and 9.99% as moderate and a FO ≥ 10% as severe. According to BIVA hydration scale of lean body mass, patients were classified as normohydrated (>72.7%-74.3%), mild (>71%-72.7%), moderate (>69%-71%) and severe (≤ 69%) dehydrated and mild (>74.3%-81%), moderate (>81%-87%) and severe (>87%) hyperhydrated. Two multivariate logistic regression models were performed: the ICU mortality was the response variable, while the predictor variables were hyperhydration, measured by BIVA (BIVA model), and FO (FO model). A p-value <0.05 was considered to indicate statistical significance.

RESULTS

One hundred and twenty-five patients were enrolled (mean age 64.8 ± 16.0 years, 65.6% male). Five hundred and fifteen BIVA measurements were performed. The mean CFB recorded at the end of the observational period was 2.7 ± 4.1 L, while the maximum hydration of lean body mass estimated by BIVA was 83.67 ± 6.39%. Severe hyperhydration measured by BIVA was the only variable found to be significantly associated with ICU mortality (OR 22.91; 95% CI 2.38-220.07; p < 0.01).

CONCLUSIONS

The hydration status measured by BIVA seems to predict mortality risk in ICU patients better than the conventional method of fluid balance recording. Moreover, it appears to be safe, easy to use and adequate for bedside evaluation. Randomized clinical trials with an adequate sample size are needed to validate the diagnostic properties of BIVA in the goal-directed fluid management of critically ill patients in ICU.

Ex Vivo Perfusion Treatment of Infection in Human Donor Lungs

Ex vivo lung perfusion (EVLP) is a platform to treat infected donor lungs with antibiotic therapy before lung transplantation. Human donor lungs that were rejected for transplantation because of clinical concern regarding infection were randomly assigned to two groups. In the antibiotic group (n = 8), lungs underwent EVLP for 12 h with high-dose antibiotics (ciprofloxacin 400 mg or azithromycin 500 mg, vancomycin 15 mg/kg, and meropenem 2 g). In the control group (n = 7), lungs underwent EVLP for 12 h without antibiotics. A quantitative decrease in bacterial counts in bronchoalveolar lavage (BAL) was found in all antibiotic-treated cases but in only two control cases. Perfusate endotoxin levels at 12 h were significantly lower in the antibiotic group compared with the control group. EVLP with broad-spectrum antibiotic therapy significantly improved pulmonary oxygenation and compliance and reduced pulmonary vascular resistance. Perfusate endotoxin levels at 12 h were strongly correlated with levels of perfusates tumor necrosis factor α, IL-1β and macrophage inflammatory proteins 1α and 1β at 12 h. In conclusion, EVLP treatment of infected donor lungs with broad-spectrum antibiotics significantly reduced BAL bacterial counts and endotoxin levels and improved donor lung function.

Inhaled nitric oxide versus sodium nitroprusside for preoperative evaluation of pulmonary hypertension in heart transplant candidates

OBJECTIVE

The development of pulmonary hypertension before heart transplantation increases the risk for postoperative right ventricular failure. Reversibility of pulmonary vascular resistance (PVR), which indicates the feasibility of heart transplantation, can be tested with the use of intravenous vasodilators, such as sodium nitroprusside (NaNTP) or prostacyclin. However, the drawback of these drugs is the development of systemic hypotension. The aim of this study was to evaluate the safely and feasibility of inhaled nitric oxide (iNO) compared with sodium nitroprusside to test PVR reversibility, while avoiding systemic hypotension.

MATERIALS AND METHODS

We included all patients who were affected by end stage heart failure undergoing evaluation for heart transplantation if they showed elevated PVR > 2.5 Wood units and mean pulmonary arterial pressure (mPAP) >25 mm Hg. The hemodynamic parameters measured by right heart catheterization were: systolic blood pressure (SBP), mPAP, pulmonary capillary wedge pressure, and cardiac index (CI). The following variables were derived: transpulmonary gradient (TPG) and PVR. All patients were tested by both iNO (20-40 ppm) and intravenous NaNTP, at increasing dosages which were titrated based on systemic pressure. We randomly assigned the order of administration of iNO and NaNTP.

RESULTS

The 9 male candidates has an average age of 56 ± 4 years. Seven of the 9 (71%) had postischemic cardiomyopathy, and 2 had idiopathic cardiomyopathy. We observed a reduction of mPAP (32% and 14%), PVR (41% and 32%), TPG (20% and 26%), and SBP (17% and 5%) and an increase of CI with administration of NaNTP and iNO, respectively.

CONCLUSIONS

We observed a reduction in PVR and mPAP with administration of either iNO and NaNTP. A better effect of NaNTP was attributed to reducted post-load of the left ventricle. However, the main advantage of iNO was the absence of systemic hypotension and its selectivity for pulmonary vascular system, as underscored by TPG reduction.

[The validation of C-POT (Critical-Care Pain Observation Tool) scale: a tool for assessing pain in intensive care patients]

Pain in intensive care units is a frequent and often undermanaged problem, mainly because appropriate pain assessment tools for non communicative patients are still missing. The Critical-Care Pain Observation Tool (C-POT) is currently considered one of the best scales, both for psychometric properties and clinical feasibility.

AIM

To preliminarily analyze the reliability and validity of the C-POT in a hospital setting, and its clinical feasibility.

METHODS

50 nursing staff members from three different critical care settings of Vicenza Hospital administered the C-POT to 121 in patients, at rest and after usual nursing care activities. In addition, NOPPAIN forms were completed during care activities and communicative patients were asked to rate their pain using numerical rating scale 0-10. Reliability, with Cronbach's alfa and inter-rater agreement (Spearman's non parametric rank correlation), as well as criterion, concurrent and discriminant validity were determined.

RESULTS

A good internal consistency and good levels of agreement between independent raters were observed (ρSpearman 0.55 at rest and 0.66 during activity). Moderate correlations between C-POT and numerical rating scale 0-10, and between C-POT and NOPPAIN were found. Moreover, C-POT scores varied from rest to activities, and from non painful to painful procedures.

DISCUSSION

C-POT showed good psychometric properties in terms of reliability and validity; these results, added to positive nurses evaluations, support its utility and use in the clinical setting.

Incidence, predictors, and outcome of conduction disorders after transcatheter self-expandable aortic valve implantation

The aims of the present study were to investigate the incidence and characteristics of conduction disorders (CDs) after transcatheter aortic valve implantation (TAVI), to analyze the predictors of permanent pacemaker (PPM) implantation, and to evaluate the outcomes of CDs over time. In particular, we sought to investigate whether the depth of deployment and other technical aspects of valve implantation might predict the need for PPM implantation after TAVI. TAVI has been reported to favor the onset or worsening of CDs often requiring PPM implantation. A total of 70 patients with aortic stenosis due to dystrophic calcification underwent TAVI with third-generation CoreValve Revalving System from May 2007 to April 2009. We collected electrocardiograms at baseline, during TAVI, during hospitalization and at the 1-, 3-, 6-, and 12-month follow-up visits thereafter. The clinical, anatomic, and procedural variables were tested to identify the predictors of PPM implantation. The PPM dependency at follow-up was analyzed. Six patients were excluded from the analysis because of a pre-existing PPM. Of the 64 patients, 32 (50%) had one or more atrioventricular-intraventricular CDs at baseline. TAVI induced a worsening in the CDs in 49 (77%) of the 64 patients, with 25 (39%) requiring in-hospital PPM implantation. On multivariate analysis, the independent predictors of PPM implantation were the depth of the prosthesis implantation (p = 0.039) and the pre-existing right bundle branch block (p = 0.046). A trend in the recovery of the CDs over time was recorded, although 2 patients required PPM implantation 1 month after discharge for late complete atrioventricular block. In conclusion, TAVI often induces or worsens CDs, requiring PPM in more than one third of patients, although a trend in the recovery of CDs during the midterm was recorded. The independent predictors of PPM implantation were the depth of prosthesis implantation and pre-existing right bundle branch block.

Effects of fenoldopam on myocardial function (strain rate) in patients with coronary artery disease undergoing cardiac surgery

BACKGROUND

This study aimed to assess the effects of fenoldopam, an antihypertensive agent with nephroprotective properties, on myocardial function. The global systolic and diastolic function and the strain rate, a new parameter used to quantify regional myocardial function, were measured with transesophageal echocardiography.

METHODS

Forty patients undergoing elective coronary artery surgery were analyzed in a prospective nonrandomized clinical trial. Patients were divided into two groups, a group that received 0.05-mcg/kg/min fenoldopam (20 patients) and a control group (20 patients). Only patients with serum creatinine levels > or =120 micromol/L and critical coronary stenosis were selected. The ejection fraction (EF), the E and A waves, and the E/A ratio were measured with transesophageal echocardiography, and the strain rate was calculated using a strain quantification program to measure the peak systolic strain rate (PSSR) and the peak diastolic strain rate (PDSR).

RESULTS

Fenoldopam did not change the systolic and diastolic global function (EF, E wave, A wave and E/A). Regarding regional myocardial function, fenoldopam significantly increased the PSSR from -1.09+/-0.8 1/s to -2.24+/-2.26 1/s (P=0.038) and the PDSR from 1.04+/-0.69 1/s to 1.69+/-0.87 1/s (P=0.012).

CONCLUSION

Low doses of fenoldopam increased the regional myocardial function, as assessed by the myocardial strain rate, in patients undergoing cardiac surgery.

Interventional approach to reduce thromboembolic risk in patients with atrial fibrillation ineligible for oral anticoagulation

The annual incidence of stroke in patients with nonrheumatic atrial fibrillation averages 5% per year and increases with age, left ventricular dysfunction, hypertension, diabetes or prior stroke. Since in nonrheumatic atrial fibrillation 91% of left atrial thrombi are located in the left atrial appendage, in patients ineligible for oral anticoagulation it was suggested the percutaneous closure of left atrial appendage as a therapeutic option to reduce embolic risk. In this article we report our initial experience with this procedure, which was uneventful and efficacious at short-term follow-up. In conclusion, the interventional approach in patients with atrial fibrillation ineligible for oral anticoagulation seems feasible and promising, and deserves further investigation.

How an undiscovered extensive peripheral pulmonary venous thrombosis destroyed a heart transplant: a case report

This report details a recent experience with a 56-year-old man affected by an incompetent mitral valve due to Barlow's disease. The patient underwent a mitral valve repair and extracorporeal membrane oxygenator (ECMO) assistance due to postcardiotomy cardiogenic shock. During the ECMO assistance he experienced a left atrial thrombosis. A few days later, being unaware of the pulmonary vein thrombosis, we transplanted the patient, who ultimately died due to multiorgan failure and coagulopathy. This article highlights both the vain experience with ECMO and the uselessness of heart transplant, to avoid in the future an irresponsible waste of donor organs, as occurred in the current case.

Critical Aortic Stenosis in Early Infancy: Surgical Treatment for Residual Lesions After Balloon Dilation

BACKGROUND

The optimal management for critical aortic stenosis in early infancy continues to challenge cardiologists and cardiac surgeons. We present a review of our experience with the surgical treatment of residual aortic valve disease after percutaneous balloon dilation for critical aortic stenosis in early infancy.

METHODS

Since 1989, 11 of the 38 patients who survived aortic balloon dilation (28.9%) have undergone surgical treatment for residual aortic valve dysfunction. Median time from aortic balloon dilation to surgical intervention was 7 months (range 1 to 56 months). Residual aortic stenosis was the predominant problem in 8 patients and aortic regurgitation was predominant in 2 patients.

RESULTS

Aortic valvuloplasty was possible in 5 children; pulmonary autograft replacement of the aortic valve was performed in 6 children. Two children underwent a Ross-Konno procedure because of annulus hypoplasia and severe left ventricular outflow tract obstruction. Two early deaths occurred after a Ross-Konno procedure, both with findings of severe left ventricular fibroelastosis at the pathologic examination. Median follow-up time was 5 years (range 1 month to 11.9 years). No late deaths occurred. One patient with moderate-severe aortic valve regurgitation after aortic valvuloplasty underwent a successful Ross operation. All 9 patients are asymptomatic and are in good clinical condition.

CONCLUSIONS

We are convinced that the best aortic valve in the pediatric age group is the native one, provided it can function acceptably. However, in cases where conservative surgical treatment fails to yield a functional aortic valve, replacement of the valve is indicated, and the best aortic valve substitute in infants is the pulmonary autograft because of its potential for growth.

Tranexamic acid in primary CABG surgery: high vs low dose

AIM

Prophylactic administration of tranexamic acid decreases bleeding and transfusions after cardiac procedures but it is still unclear what the best dose and the most appropriate timing to get the best results are.

METHODS

We enrolled 250 patients scheduled for elective, primary coronary revascularization. They were randomly divided into 2 groups. Group H received tranexamic 30 mg x kg(-1) soon after the induction of anaesthesia and a further same dose was added to the prime solution of cardiopulmonary bypass (CPB). Group L received tranexamic acid 15 mg x kg(-1) after systemic heparinization followed by an infusion of 1 mg x kg(-1) h(-1) till the end of the operation. Transfusions of bank blood products, bleeding in the postoperative period and coagulation profile were recorded.

RESULTS

We did not find any difference between the groups either with respect to transfusion requirements or with respect to blood loss.

CONCLUSION

For elective, first time coronary artery bypass surgery, both dosages of tranexamic acid are equally effective. Theoretically, it seems safer to administer it when patients are protected from thrombus formation by full heparinization.

Ventriculo-arterial coupling and mechanical efficiency with remifentanil in patients with coronary artery disease

BACKGROUND

Optimum transfer of energy from the left ventricle to the arterial circulation requires appropriate matching of these mechanical systems. Left ventricular-arterial coupling describes this relationship between the ventricular elastance (Ees) and arterial elastance (Ea). The ratio of these elastances defines the efficiency of myocardium and provides in our study a useful technique for assessment of the actions of remifentanil. The purpose of this study was to evaluate the effects of remifentanil on ventriculo-arterial coupling in cardiac surgery in patients with coronary artery disease.

METHODS

Fourteen patients with coronary artery disease, submitted intraoperatively to cardiac anesthesia for myocardial revascularization, were examined prospectively. With the use of transesophageal echocardiography (TEE) and different dicrotic arterial pressures, we determined the ventricle elastance (Ees), the arterial elastance (Ea) and myocardial efficiency before and after administration of a slow-bolus of remifentanil (1 micro kg(-1)).

RESULTS

Remifentanil decreases significantly the ventricular elastance (from 6.09 mmHg ml-1 m(-2) to 4.88) (P < 0.05), with a less, but however, significant decrease of arterial elastance (from 3.68 mmHg ml(-1) m(-2) to 3.13) (P < 0.05). Despite causing simultaneous declines, maintains a good myocardial efficiency (0.64-0.68) with no significant difference.

CONCLUSION

Although remifentanil depresses ventricular and arterial elastance, preserves a good left ventricular-arterial coupling and mechanical efficiency, despite a little increase of coupling. However, these effects are maintained only during a slow intravenous infusion and are dose-dependent with impairment of coupling, that may contribute to decline in overall cardiovascular performance, at higher anesthetic dose and rapid infusion in patients with a severe myocardial dysfunction.

Surgical treatment of complete A-V canal defects in children before 3 months of age

OBJECTIVES

Surgical repair of complete A-V canal defects (CAVCD) is a well established procedure which is currently performed in infancy. The aim of this study is to evaluate surgical results of correction in early infancy in comparison to older age.

METHODS

From January 1985 to March 2001, 119 consecutive patients (age range 27 days to 83 months, mean 6.7 months) underwent repair of CAVCD in our Institution. Forms with unbalanced ventricles in association with Fallot's tetralogy or heterotaxia were excluded from this series. Fifty-eight patients (49%) underwent correction before 3 months of age (Group A), and 61 patients (51%) after 3 months (Group B). Surgical repair was accomplished with a double patch technique in 100 patients (84%). Associated surgical lesions were treated simultaneously in 48 patients (40%).

RESULTS

There were 11 operative deaths (<30 days) (two in Group A (3.4%) and nine in Group B (15%)) (P = 0.05). The remaining patients were discharged home in good haemodynamic condition. Reoperation for postoperative left A-V incompetence occurred in five patients in Group A and in eight patients in Group B. There were eight late deaths (three in Group A and five in Group B), of which four were non-cardiac related. At a mean follow-up time of 80 months (range 2-184 months) 100 patients are asymptomatic and well, and free from oral medication. Echocardiographic examination showed absent or mild residual left A-V valve incompetence in 91 patients (49 in Group A and 42 in Group B) and moderate left A-V valve incompetence in nine patients (four in Group A and five in Group B). Kaplan-Meier survival estimates at 10 years were 90% for Group A and 75% for Group B. Kaplan-Meier freedom from reoperation at 10 years was 89% for Group A and 84% for Group B.

CONCLUSIONS

Our data demonstrate that repair of CAVCD under 3 months of age is the ideal approach to this malformation with a lower mortality rate at operation compared to older patients. Logistic analysis showed that an operative age >3 months is, compared to an age < or =3 months, an incremental risk factor for hospital mortality with an odds ratio of 4.8 (95% confidence limit 1-23.5) (P = 0.05). In the long term, freedom from reoperation for left A-V valve incompetence is higher when compared to children repaired at an older age.

[Noncardiac surgery and congenital heart diseases: pathophysiological approach]

Aim of this paper is to describe an approach to the patient with congenital heart disease (CHD) who is undergoing noncardiac surgery. Emphasis is placed on the pathophysiology of the lesion in order to facilitate the development of an anesthetic planning. There are three general categories of CHD: obstructive lesions, increased pulmonary blood flow lesions and decreased pulmonary blood flow lesions. Alterations in systemic and/or pulmonary vascular resistances lead to alterations in the quantity of pulmonary blood flow and the ventricles' ability to pump against an obstruction. Selection of anesthetic medications which preserve ventricular function and vascular resistances in a fashion which best maintain pulmonary blood flow and oxygenation and forward cardiac output are the anesthesiologist's goals. No single simple unified approach can be taken when providing anesthesia for the patient with CHD for noncardiac surgery; however, by evaluating each patient's hemodynamic needs in relation to hemodynamic variables which the anesthesiologist may control, a rational and individualized approach can be developed.

[Alterations in left ventricular-arterial coupling and mechanical efficiency produced by remifentanil during cardiac anesthesia]

BACKGROUND

The performance of the cardiovascular system depends on the interaction of the left ventricle and arterial system. An appropriate coupling of these two components is important to quantify the efficiency of myocardium, determined by Ea/Ees. The end-systolic elastance of the left ventricle (Ees) is an index of contractility which is independent of loading conditions, while the arterial end-systolic elastance (Ea) represents the properties of the arterial system. The aim of our study is to investigate the effects of a bolus of remifentanil (R) on myocardial efficiency.

METHODS

In a period of 3 months we examined prospectively the effects of R in a group of 12 patients, ASA IV, 49-75 years old, submitted intraoperatively to cardiac anesthesia for revascularization of myocardium. After induction of anesthesia and before the beginning of surgery, a bolus of R (1 mg/kg/min) was administered and with the use of trans-esophageal echocardiography we determined both the left ventricle end-systolic volume and end-diastolic volume to assess, with different end-systolic arterial pressures, the ventricle elastance (Ees) and arterial elastance (Ea) before and after administration of R.

RESULTS

The present findings indicate that R decreases the ventricular elastance from 6.07 mmHg/ml/m2 to 4.8, with a less decrease of arterial elastance from 3.69 mmHg/ml/m2 to 3.07.

CONCLUSIONS

The results suggest that R preserves a good left ventricular-arterial coupling and mechanical efficiency, despite a little increase of coupling, probably because ventricular and arterial properties are so matched as to minimize the systolic work of the left ventricle.

[The value of transesophageal echocardiography during cardiac surgery]

The intraoperative use of two-dimensional transesophageal echocardiography has proved effective in the evaluation of left ventricular function after heart operations, in the assessment of adequacy of valve replacement or repair techniques, and in the detection of intracardiac air bubbles before discontinuation of cardiopulmonary bypass. We report here a patient in whom the presence of a tumor mass in the left leaflet of the aortic valve, which was missed at preoperative transthoracic echocardiogram and would have most likely been the cause of systemic embolization, was diagnosed by two-dimensional transesophageal echocardiographic monitoring. We hope that this experience may support the use of two-dimensional transesophageal echocardiography during cardiac surgery.

Intraoperative plasmapheresis in cardiac surgery

OBJECTIVE

To determine the effects of intraoperative plasmapheresis on total transfusion requirements, mediastinal drainage, and coagulation.

DESIGN

The trial was prospective, randomized, and controlled.

SETTING

Inpatient cardiac surgery at a university medical center.

PARTICIPANTS

Two hundred ninety-three consecutive patients undergoing cardiac surgery requiring cardiopulmonary bypass.

INTERVENTIONS

Intraoperative plasmapheresis (IP) was performed in 147 patients before heparinization; platelet-rich plasma was reinfused immediately after heparin reversal.

MEASUREMENTS AND MAIN RESULTS

Mediastinal chest tube drainage during the first 12 postoperative hours was significantly less in the IP group (p = 0.022), but no difference was noted in total postoperative blood loss between the two groups. The amount of packed red cells and fresh frozen plasma transfused to the IP group in the intensive care unit was significantly lower (p = 0.02, p = 0.002, respectively); 51.4% of patients required no transfusion compared with the control group (34.5%) (p = 0.006). No differences were noted for data collected in the intensive care unit in terms of the mean duration of chest tube drainage, ventilator time, or any hematologic variables at baseline or at any subsequent time in the study.

CONCLUSIONS

After cardiac surgery, intraoperative plasma-pheresis reduces early postoperative bleeding and decreases the need for homologous transfusions.

A comparison of period amplitude and power spectral analysis of sleep EEG in normal adults and depressed outpatients

Three experiments were carried out to evaluate the relationship between two techniques for quantifying electroencephalographic (EEG) data during sleep: period amplitude analysis (PAA) and power spectral analysis (PSA). In Experiment 1, canonical correlations and regression analyses were computed on PSA and PAA data from 40 undergraduate volunteers. The results yielded an average canonical correlation of 0.98. Further, multiple regression analyses demonstrated that the PSA variables accounted for approximately 66% of the variance in the PAA data, whereas PAA variables captured 88% of the variance in the PSA data. Epoch-to-epoch correlations were higher for PAA measures than for PSA data, perhaps indicating greater stability of PSA measures across epochs of sleep. In Experiment 2, PSA and PAA data were compared in 17 unmedicated outpatients with unipolar depression. Canonical correlations and regression analyses indicated that the overlap in variance between PSA and PAA did not exceed 50%, regardless of whether PSA or PAA variables were used as predictors. Epoch-to-epoch correlations between PAA measures were significantly higher than correlations among PSA variables, again suggesting greater stability of PAA data across epochs of sleep. The range of correlations for either data set was, however, substantially lower in the depressed than in the normal group. Experiment 3 evaluated the possibility that filter settings and artifact-rejection procedures had contributed to reduced overlap in PSA-PAA variance and reduced stability in depressed patients. An additional group of eight healthy volunteers served as subjects. Findings in Experiment 3 indicated that methodological differences between Experiments 1 and 2 did not account for the reduced correlations in the depressed group. It was concluded that PSA and PAA data should be comparable in normal subjects but are relatively independent in depressed patients. Epoch-to-epoch correlations were higher for PAA data than those found between PSA measures in both normal subjects and depressed patients, suggesting that PAA may be more stable across sleep epochs. Reduced stability may be a reflection of nonstationarity in the EEG of depressed patients.

Recurrent thrombosis of Omniscience prostheses in the mitral position: a case report

We report a patient who experienced thrombotic obstruction of an Omniscience prosthesis three years after mitral valve replacement. At reoperation another Omniscience prosthesis was inserted which became thrombosed after eight months. Recurrent thrombosis of the same prosthesis in the same patient is unusual and raises the problem of which device to use when replacing a thrombosed valve. In our patient another mechanical prosthesis was inserted at second reoperation because of her young age and in the hope of reducing the risk of further thrombosis by using a valve with better flow characteristics such as a bileaflet prosthesis.

Propofol-fentanyl versus isoflurane-fentanyl anesthesia for coronary artery bypass grafting: effect on myocardial contractility and peripheral hemodynamics

To avoid intraoperative awareness and postoperative respiratory depression from high-dose opioid anesthesia, propofol (P), or isoflurane (I) has been combined with moderate-dose opioid with varying results. However, the effects of both P and I on myocardial contractility and left ventricular afterload have not been completely quantified. The end-systolic pressure-diameter relationship (ESPDR) of the left ventricle (LV) is a reliable method to quantitatively assess LV contractility because it is relatively independent of changes in preload and incorporates afterload changes. The purpose of this study was to quantify the cardiodynamic effects of propofol-fentanyl (PF) anesthesia in comparison with isoflurane-fentanyl (IF) anesthesia in patients undergoing coronary artery bypass grafting (CABG). Thirty patients with normal or moderately impaired LV function (ejection fraction > or = 40% with LV end-diastolic pressure < or = 18 mmHg, no preoperative akinesia or dyskinesia) undergoing elective CABG were studied. After premedication with flunitrazepam, 2 mg orally, all patients were induced with thiopental, 1 mg/kg, fentanyl, 20 micrograms/kg, and vecuronium, 0.1 mg/kg, and were ventilated with oxygen/air (F(1)O2 0.6). Anesthesia was maintained throughout the procedure with a zero-order intravenous (IV) continuous infusion of P, 3 mg/kg/h (PF group), or with isoflurane inhalation of 0.6% (IF group), supplemented by intermittent boluses (5 micrograms/kg) of fentanyl (up to a total maintenance dose of 30 micrograms/kg). After intubation, a cross-section of the LV was visualized by two-dimensional transesophageal echocardiography and an m-mode echocardiogram was obtained at the maximum anterior-posterior diameter. The radial artery pressure tracing and the ECG were simultaneously recorded with the M mode.(ABSTRACT TRUNCATED AT 250 WORDS)

[A case of neonatal extracorporeal membrane oxygenation after heart surgery]

There is international experience of Extracorporeal Membrane Oxygenation (ECMO) in children suffering acute Respiratory failure (eg. meconium aspiration syndrome); on the contrary there is a lack of consistent experience in pediatric ECMO application in cardiac surgery as bridge to cardiac transplantation and as heart mechanical support after postcardiotomy failure. In fact there are good standardization criteria for selection, inclusion and exclusion in ECMO application for neonatal respiratory failure; differently pediatric ECMO timing (that is when to start and to stop this ventricular support) is not clear and standardized. We present one case of pediatric ECMO application in a neonate, who underwent cardiac operation for pulmonary valve aplasia and who was impossible to wean from cardiopulmonary bypass.

[A case of double valve substitution in a female patient carrier of a factor X deficiency]

We present the clinical case of a patient affected by mitral and aortic valvular disease submitted to double valvular replacement. This patient was also affected by congenital deficiency of factor X. We describe the normal problems encountered in cardiac surgery and the specific implications of this clinical case.