Goal-directed therapy in cardiac surgery: a systematic review and meta-analysis

BACKGROUND

Perioperative mortality after cardiac surgery has decreased in recent years although postoperative morbidity is still significant. Although there is evidence that perioperative goal-directed haemodynamic therapy (GDT) may reduce surgical mortality and morbidity in non-cardiac surgical patients, the data are less clear after cardiac surgery. The objective of this review is to perform a meta-analysis on the effects of perioperative GDT on mortality, morbidity, and length of hospital stay in cardiac surgical patients.

METHODS

We conducted a systematic review using Medline, EMBASE, and the Cochrane Controlled Clinical Trials Register. Additional sources were sought from experts. The inclusion criteria were randomized controlled trials, mortality reported as an outcome, pre-emptive haemodynamic intervention, and cardiac surgical population. Included studies were examined in full and subjected to quantifiable analysis, subgroup analysis, and sensitivity analysis where possible. Data synthesis was obtained by using odds ratio (OR) and mean difference (MD) for continuous data with 95% confidence interval (CI) utilizing a random-effects model.

RESULTS

From 4986 potential studies, 5 met all the inclusion criteria (699 patients). The quantitative analysis showed that the use of GDT reduced the postoperative complication rate (OR 0.33, 95% CI 0.15-0.73; P=0,006) and hospital length of stay (MD -2.44, 95% CI -4.03 to -0.84; P=0,003). There was no significant reduction in mortality.

CONCLUSION

The use of pre-emptive GDT in cardiac surgery reduces morbidity and hospital length of stay.

Raised serum cardiac troponin I concentrations predict hospital mortality in intensive care unit patients

BACKGROUND

Recent work suggests that increased plasma concentrations of cardiac troponin I (cTnI) are common in critically ill patients and are associated with poor outcome. We measured the frequency of increased plasma cTnI concentrations during patients' stay in a mixed medical/surgical intensive care unit (ICU) and compared our findings with hospital mortality.

METHODS

Basic details, organ support, and hospital mortality were recorded for all patients treated in ICU during a 6 month period. cTnI concentrations were sampled daily for all patients, using 0.04 µg litre(-1) as the upper limit of normal, and 0.12 µg litre(-1) as an additional stratification point.

RESULTS

Of 663 patients, 54% were male, with a mean (sd) age of 60 (18) yr, 65% were surgical patients, and the median Acute Physiology and Chronic Ill Health II (APACHE II) score was 15 (inter-quartile range 12-20). Increased cTnI concentrations were found in 345 patients (52%) while in ICU. One hundred and twenty patients (18%) died in hospital. cTnI concentration >0.04 µg litre(-1) was associated with reduced odds of hospital survival, independent of age, medical admission, unplanned admission, APACHE II score, mechanical ventilation, and haemofiltration (adjusted odds ratio 0.25, 95% confidence interval 0.08-0.75, P=0.014). Stratification by the degree of cTnI increase revealed an incremental trend towards a lower odds of hospital survival, including for patients with 'minor' elevations of cTnI (0.05-0.12 µg litre(-1)).

CONCLUSIONS

Increased serum cTnI concentrations during ICU stay independently predicts hospital mortality, even when the threshold is low. We found a trend towards an association between 'minor' elevations in cTnI and higher in-hospital mortality.

Efficacy of functional hemodynamic parameters in predicting fluid responsiveness with pulse power analysis in surgical patients

BACKGROUND

In this study we quantify the ability of dynamic cardiovascular parameters measured by the PulseCO™ algorithm of the LiDCO™plus monitor to predict the response to a fluid challenge in post-operative patients.

METHODS

Surgical patients, admitted to the Intensive Care Unit from the operating theatre were monitored with the LiDCO™plus system. A number of static and dynamic cardiovascular measurements were recorded before and after a fluid challenge. Receiver Operator Characteristic (ROC) curve analysis was used to identify the baseline values, with optimum sensitivity and specificity, to predict responsiveness to a fluid challenge.

RESULTS

Thirty-one patients were enrolled, and received protocol-based fluid challenges. Twelve (38%) responded by demonstrating an increase in stroke volume of >15%. Heart rate (HR) and central venous pressure (CVP) were not statistically different between responders and non-responders. Mean arterial pressure (mAP), systolic pressure variation (SPV), pulse pressure variation (PPV) and stroke volume variation (SVV) were statistically different between responders and non-responders. Parameters with a ROC area under the curve (AUC) significantly >0.5 included SPV 0.70 (0.52-0.88) P=0.046, PPV 0.87 (0.76-0.99) P<0.0002 and SVV 0.84 (0.71-0.96) P=0.0005. The best cut-off values (sensitivity and specificity) to predict fluid were SPV >9 mmHg (73%, 76%), PPV >13% (83%, 74%) and SVV >12.5% (75%, 83%). ROC analysis did not show the AUC to be significantly >0.5 for HR, mAP and CVP CONCLUSION: Dynamic indices measured by PulseCO™ (LiDCO) have a high sensitivity and specificity in predicting fluid responsiveness in sedated and mechanically ventilated patients. A cut-off value for PPV of 13% is the most sensitive and specific indicator of fluid responsiveness.

Severity assessment tools in ICU patients with 2009 influenza A (H1N1) pneumonia

The aim of this study was to determine if severity assessment tools (general severity of illness and community-acquired pneumonia specific scores) can be used to guide decisions for patients admitted to the intensive care unit (ICU) due to pandemic influenza A pneumonia. A prospective, observational, multicentre study included 265 patients with a mean age of 42 (±16.1) years and an ICU mortality of 31.7%. On admission to the ICU, the mean pneumonia severity index (PSI) score was 103.2 ± 43.2 points, the CURB-65 score was 1.7 ± 1.1 points and the PIRO-CAP score was 3.2 ± 1.5 points. None of the scores had a good predictive ability: area under the ROC for PSI, 0.72 (95% CI, 0.65-0.78); CURB-65, 0.67 (95% CI, 0.59-0.74); and PIRO-CAP, 0.64 (95% CI, 0.56-0.71). The PSI score (OR, 1.022 (1.009-1.034), p 0.001) was independently associated with ICU mortality; however, none of the three scores, when used at ICU admission, were able to reliably detect a low-risk group of patients. Low risk for mortality was identified in 27.5% of patients using PIRO-CAP, but above 40% when using PSI (I-III) or CURB65 (<2). Observed mortality was 13.7%, 13.5% and 19.4%, respectively. Pneumonia-specific scores undervalued severity and should not be used as instruments to guide decisions in the ICU.

P5-07-01: Novel Alternative Splice Variants of HER2 in Invasive Breast Cancer

Background: The Human Epidermal Growth Factor Receptor 2 (HER2) is an oncogene expressed in 25–30% of invasive breast cancers. HER2 shares extensive homology with other members of the HER family (HER1, HER3 and HER4), and is constitutively active as an homo- and heterodimer. The HER2 gene encodes an 185kDa transmembrane protein with tyrosine kinase activity. Gene amplification or protein expression of HER2 is a predictor of poor clinical outcome and decreased survival in women with breast cancer, and also indicates a favourable response to Trastuzumab (Herceptin) therapy, or a combinational therapy comprising Herceptin plus chemotherapy. However, resistance to Trastuzumab remains the case in approximately 50% of HER2 amplified/overexpressing tumours. Understanding the molecular mechanisms of Trastuzumab resistance and identifying more effective therapies, is critical in the treatment of patients whose breast cancers express this aggressive disease phenotype. In this study, it is postulated that the abnormal generation of mRNA splice variants may be responsible for the continued tumour growth and progression.

Aims: The aim of this study is to increase our understanding of the role of HER-2 splice variants in the development and progression of breast cancer. This will inform the development of more sophisticated and effective therapies that target specific HER-2 isoforms, rather than Herceptin, which targets just the generic wild type HER-2 protein. Materials and Methods: The entire coding region of HER-2 cDNA was PCR amplified using 12 sets of HER-2 specific primers in HER-2 positive cell lines (SKOV-3, SKBR-3, MDA-MB-453 and MDA-MB-361).

Results: RT-PCR results showed multiple bands in various regions of the HER2 mRNA. Sequencing of these bands revealed novel alternative splice variants with deletions in exons 13 and 18 of the HER2 gene expressed in addition to the wild type HER2. Bioinformatic analysis of the deletions revealed a cassette exon deletion in exon 13, and a loss of 42 base pairs in the 3’ end of exon 18 compared to the full length HER2. Both the full length HER2 sequence and the sequence containing the deletions were translated using the ExPASy Translate Tool. This revealed an in-frame deletion of 14 amino acids and revealed a novel splice isoform with a deletion in the HER2 protein which encompasses the entire ATP binding pocket. This was determined by analysis using UniProtKB to identify the composition of amino acids for each domain of HER2. Discussion: Our studies have identified novel splice variants in the tyrosine-kinase domain of the HER-2 gene using HER-2 positive cell lines. The loss of an ATP binding site in the HER2 gene may lead to a less active HER2 isoform which may play a significant role in prognosis. Current work is being carried out to study the regulation of these splice variants and to study the role of splice factors ASF/SF2 and SRPK1 in the regulation of HER2 splicing, and to elucidate any significant changes in the HER2 signalling pathways. In addition, the expression of these isoforms are currently being investigated in tissues from formalin fixed, paraffin embedded and frozen breast tumours.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P5-07-01.

Epidemiology and outcome following post-surgical admission to critical care

PURPOSE

To describe the factors related to outcome in patients admitted to the intensive care unit (ICU) after major surgery at a national level (in Austria).

METHODS

Analysis of a prospectively collected database of ICU admissions over an 11-year period. Factors associated with mortality and how this changed with time were explored using logistic multilevel modelling.

RESULTS

A total of 88,504 surgical patients had a mean ICU length of stay of 6.5 days and total hospital stay of 31.3 days. They had an ICU mortality of 7.6% and a hospital mortality of 11.8%. Factors associated with hospital mortality included age (odds ratio (OR) 1.42 per 10 years of age), urgency of operation (2.02 for emergency when compared to elective), SAPS II score (OR 1.09), reason for admission being a medical cause and the specific nature of the surgery itself: thoracic (OR 1.81), cardiovascular (OR 1.25), trauma (OR 1.22) or gastrointestinal surgery (OR 1.71). In addition patients who had pre-existing chronic renal (OR 1.40), respiratory (OR 1.20) or cardiac failure (OR 1.29), cirrhosis (OR 2.50), alcoholism (OR 1.42), acute kidney injury (OR 1.88) and/or non-metastatic cancer (OR 1.20) were associated with higher hospital mortality than patients without this co-morbidity. There was a reduction in the OR for death over the whole 11-year period. This improved outcome remained valid even after adjusting for the identified risk factors for mortality (OR per year 0.96).

CONCLUSIONS

This study has shown the high level of demand for critical care for this patient group and an improving rate of survival.

Comparison of breast cancer in Indonesia and Malaysia--a clinico-pathological study between Dharmais Cancer Centre Jakarta and University Malaya Medical Centre, Kuala Lumpur

INTRODUCTION

The age standardised incidence rate (ASR) of breast cancer in Malaysia which is a high middle- income country is similar to Indonesia, a low middle-income country. (Globocan 2008) It is however unknown whether the presentation of breast cancer differs between these two countries.

OBJECTIVE

We compared the stage, age at presentation, and pathological characteristics of breast cancer between two tertiary hospitals in Indonesia and Malaysia; Dharmais Cancer Centre (DCC), which is the national cancer referral centre in Indonesia, and University Malaya Medical Centre (UMMC), which is an academic hospital with established breast oncology services in Kuala Lumpur. One thousand, one hundred and fourteen consecutive women (477 in UMMC: 637 in DCC) who were newly diagnosed with breast cancer between January and December, 2010 were included. Patient's age, TNM stage at presentation, and pathological characteristics were compared. Estrogen receptor (ER) and progesterone receptor (PR) were considered positive if 10% or greater of invasive cell nuclei were stained while HER2 was considered positive with an immunohistochemistry staining intensity of 3+ . Logistic regression analyses were performed to identify differences.

RESULTS

Median age at diagnosis was 52 years in UMMC and 47 years in DCC, whereby patients in DCC were more likely to be very young at diagnosis (aged < 35 years) compared to their counterparts in UMMC (Odds ratio (OR): 2.09; 95%CI: 1.32-3.31). Approximately one third of patients in UMMC presented with TNM stage III or IV, compared to 63% in DCC. Patients in DCC were three times more likely to present with metastatic breast cancer compared to patients in UMMC (OR: 3.01; 95% CI: 2.02-4.48). The percentage of low grade tumours in DCC was higher than in UMMC (28% vs 11% respectively), and the difference persisted even after multivariate adjustment. Although the frequency of ER and PR positivity appeared to be higher in UMMC (65% and 55% respectively) compared to DCC (48% and 40% respectively), these differences were not statistically significant following adjustment for age, stage, HER2 status and grade. The frequency of HER2 positivity was 45% in DCC compared to 26% in UMMC, and remained significantly higher even after multivariate adjustment (multivariate OR:1.76; 95%CI:1.25-2.47, in DCC compared to UMMC). The proportion of triple negative breast cancer was however similar in the two centres (19% in UMMC vs 21% in DCC).

CONCLUSION

Indonesian women with breast cancer seem to present at a younger age and at later stages compared to Malaysian women. Their tumors were more likely to be of low grade and HER2 positive, even after adjustment for other factors, while hormone receptor positivity proved similar in the two groups. The higher HER2 positivity rate in Indonesian patients warrants further study.

A prospective study of the accuracy and precision of continuous cardiac output monitoring devices as compared to intermittent thermodilution

BACKGROUND

Pulse pressure (PP) analysis from a radial arterial line is available with the LiDCO plus monitor (LiDCO, Cambridge, UK) and FloTrac/Vigileo (Edwards Lifesciences, Irvine, CA, USA). The aim of this study was to investigate the agreement of continuous PP analysis against intermittent thermodilution (ITD) using the pulmonary artery catheter (PAC).

METHODS

This was a six-hour study in 29 patients monitored with a PAC. All measurements were referenced against CO measured from the average of four ITD curves from the PAC. The LiDCO plus was calibrated with a lithium dilution (PulseCOLi) and with ITD (PulseCOITD) at baseline. Measurements from Vigileo software 1.03 (APCO), LiDCO plus (PulseCOLi and PulseCOITD), CCO and ITD were taken every hour for the next six hours. The bias and precision between the two devices were calculated as well as the percentage error (PE) of agreement between the tested device and the reference. The coefficient of variation (CV) of the tested device was then derived.

RESULTS

The average bias, PE and coefficient of variation for CCO vs. ITD of the tested device were 0.3 L/min, 28% and 13%, respectively; for APCO vs. ITD the calculations were -1.1 L/min, 55% and 27%; for PulseCOLi Cardiac output Blood pressure Thermodilution. ITD they were 0.5 L/min, 40% and 19%; and for PulseCOITD vs. ITD they were 0.2 L/min, -31% and 15%.

CONCLUSION

APCO (Vigileo software 1.03) and PulseCOLi showed a moderate agreement with the PAC. When PulseCO was calibrated with ITD (PulseCOITD) it showed excellent agreement, demonstrating that PulseCO performs well against ITD when the calibration process is optimally performed.

Use of early corticosteroid therapy on ICU admission in patients affected by severe pandemic (H1N1)v influenza A infection

INTRODUCTION

Early use of corticosteroids in patients affected by pandemic (H1N1)v influenza A infection, although relatively common, remains controversial.

METHODS

Prospective, observational, multicenter study from 23 June 2009 through 11 February 2010, reported in the European Society of Intensive Care Medicine (ESICM) H1N1 registry.

RESULTS

Two hundred twenty patients admitted to an intensive care unit (ICU) with completed outcome data were analyzed. Invasive mechanical ventilation was used in 155 (70.5%). Sixty-seven (30.5%) of the patients died in ICU and 75 (34.1%) whilst in hospital. One hundred twenty-six (57.3%) patients received corticosteroid therapy on admission to ICU. Patients who received corticosteroids were significantly older and were more likely to have coexisting asthma, chronic obstructive pulmonary disease (COPD), and chronic steroid use. These patients receiving corticosteroids had increased likelihood of developing hospital-acquired pneumonia (HAP) [26.2% versus 13.8%, p < 0.05; odds ratio (OR) 2.2, confidence interval (CI) 1.1-4.5]. Patients who received corticosteroids had significantly higher ICU mortality than patients who did not (46.0% versus 18.1%, p < 0.01; OR 3.8, CI 2.1-7.2). Cox regression analysis adjusted for severity and potential confounding factors identified that early use of corticosteroids was not significantly associated with mortality [hazard ratio (HR) 1.3, 95% CI 0.7-2.4, p = 0.4] but was still associated with an increased rate of HAP (OR 2.2, 95% CI 1.0-4.8, p < 0.05). When only patients developing acute respiratory distress syndrome (ARDS) were analyzed, similar results were observed.

CONCLUSIONS

Early use of corticosteroids in patients affected by pandemic (H1N1)v influenza A infection did not result in better outcomes and was associated with increased risk of superinfections.

Patient safety in anesthesia

Medical mistakes have been identified as resulting from a breakdown in one or more of five major areas: equipment performance, communication, staffing levels, complex environments and workloads. Because many of these areas relate directly to the practice of anesthesiology, they can contribute significantly to the safety and quality of the use of anesthesia. The specialty of anesthesia has embraced a culture of safety, resulting in many beneficial improvements for patients. The avoidance of error has led to improved outcomes, with a decrease in directly attributable rates of morbidity and mortality. Despite these improved rates, there are still areas that can be improved. This paper describes the background of these issues, discusses areas where performance has improved and identifies the areas in which there is room for further improvement.

C-reactive protein as a predictor of outcome after discharge from the intensive care: a prospective observational study

BACKGROUND

Recent studies have found plasma C-reactive protein (CRP) to be a predictor of outcome after discharge from the intensive care unit (ICU). To assess the generalizability of this finding, we assessed the value of CRP on the day of ICU discharge as a predictor of unplanned ICU readmission and unexpected death within 2 weeks. Plasma albumin and white cell count at discharge were also considered as markers associated with ongoing inflammation.

METHODS

This was a single-centre observational study involving a medical-surgical ICU in a university teaching hospital. Data were prospectively collected from 1487 admissions involving 1401 patients over a 12 month period. Patients' admission details and APACHE II score were collected in addition to plasma CRP, white cell count, and albumin values from the day of discharge from ICU. We assessed the difference in these variables between patients who were readmitted, who died unexpectedly, and those who did not.

RESULTS

We found that 9.9% of patients discharged were either readmitted (7.0%) or died unexpectedly (2.9%). Patients who were readmitted had a lower plasma albumin concentration [20 (16, 24) vs 22 (19, 27), P<0.001] and a higher admission APACHE II score [median (inter-quartile range, IQR) 16.5 (13, 21) vs 15 (12, 18), P=0.02]. Patients who died unexpectedly on the ward were older [mean (sd): 76 (12) vs 59 (19), P<0.001] and had a higher APACHE II score [21 (17.25, 26) vs 15 (12, 18), P<0.001]. There was not a statistically significant difference in CRP concentration between patients who either required ICU readmissions or died unexpectedly on the ward and those who did not.

CONCLUSIONS

In a mixed medical-surgical intensive care, plasma CRP measured at the day of discharge from intensive care is not a predictor of readmissions or deaths.

Modelling the impact of an influenza A/H1N1 pandemic on critical care demand from early pathogenicity data: the case for sentinel reporting

Projected critical care demand for pandemic influenza H1N1 in England was estimated in this study. The effect of varying hospital admission rates under statistical uncertainty was examined. Early in a pandemic, uncertainty in epidemiological parameters leads to a wide range of credible scenarios, with projected demand ranging from insignificant to overwhelming. However, even small changes to input assumptions make the major incident scenario increasingly likely. Before any cases are admitted to hospital, 95% confidence limit on admission rates led to a range in predicted peak critical care bed occupancy of between 0% and 37% of total critical care bed capacity, half of these cases requiring ventilatory support. For hospital admission rates above 0.25%, critical care bed availability would be exceeded. Further, only 10% of critical care beds in England are in specialist paediatric units, but best estimates suggest that 30% of patients requiring critical care will be children. Paediatric intensive care facilities are likely to be quickly exhausted and suggest that older children should be managed in adult critical care units to allow resource optimisation. Crucially this study highlights the need for sentinel reporting and real-time modelling to guide rational decision making.