Association of positive fluid balance and mortality in sepsis and septic shock in an Australian cohort.

In patients with septic shock, a correlation between positive fluid balance and worsened outcomes has been reported in multiple observational studies worldwide. No published data exists in an Australasian cohort. We set out to explore this association in our institution. We conducted a retrospective audit of patient records from August 2012 to May 2015 in a single-centre, 24-bed surgical and medical intensive care unit (ICU) in Sydney, Australia. All patients with septic shock were included. Exclusion criteria included length of stay less than 24 hours or vasopressors needed for less than six hours. Data was gathered on fluid balance for the first seven days of ICU admission, biochemical data and other clinical indices. The primary outcome measure was survival to hospital discharge. One hundred and eighty-six patients with septic shock were included, with an overall hospital mortality of 23.7%. Seventy-five percent of patients required mechanical ventilation, and 27.4% required haemodialysis. The mean daily fluid balance on the first day of admission was positive 1,424 ml and 1,394 ml for ICU and hospital survivors, respectively. On average, the daily fluid balance for non-survivors was higher than the survivors: ICU non-survivors were 602 (95% confidence intervals 230, 974) ml (P=0.0015) and hospital non-survivors were 530 [95% confidence intervals 197, 863] ml (P=0.0017) more than the survivors. In line with other recently published data, after adjustment for confounders (severity of illness based on the Acute Physiology and Chronic Health Evaluation score) we found a correlation between positive fluid balance and worsened hospital mortality in critically ill patients with sepsis and septic shock. Further research investigating rational use of fluids in this patient group is needed.

Surviving sepsis campaign: international guidelines for management of sepsis and septic shock: 2016

OBJECTIVE: To provide an update to "Surviving Sepsis Campaign Guidelines for Management of Sepsis and Septic Shock: 2012". DESIGN: A consensus committee of 55 international experts representing 25 international organizations was convened. Nominal groups were assembled at key international meetings (for those committee members attending the conference). A formal conflict-of-interest (COI) policy wasdeveloped at the onset of the process and enforced throughout. A stand-alone meeting was held for all panel members in December 2015. Teleconferences and electronic-based discussion among subgroupsand among the entire committee served as an integral part of the development. METHODS: The panel consisted of five sections: hemodynamics, infection, adjunctive therapies, metabolic, and ventilation. Population, intervention, comparison, and outcomes (PICO) questions were reviewed and updated as needed, and evidence profiles were generated. Each subgroup generated a list of questions, searched for best available evidence, and then followed the principles of the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system to assess the quality of evidence from high to very low, and to formulate recommendations as strong or weak, or best practice statement when applicable. RESULTS: The Surviving Sepsis Guideline panel provided 93 statements on early management and resuscitation of patients with sepsis or septic shock. Overall, 32 were strong recommendations, 39 were weak recommendations, and 18 were best-practice statements. No recommendation was provided for four questions. CONCLUSIONS: Substantial agreement exists among a large cohort of international experts regarding many strong recommendations for the best care of patients with sepsis. Although a significant number of aspects of care have relatively weak support, evidence-based recommendations regarding the acute management of sepsis and septic shock are the foundation of improved outcomes for these critically ill patients with high mortality.(AU)

Left ventricular outflow tract obstruction-be prepared!

The current trend to treat hypotension in critically ill patients is to place a greater emphasis on inotropic support and less on fluid resuscitation in order to limit the potential harm from fluid overload. This combination may trigger left ventricular outflow tract obstruction (LVOTO) in susceptible patients. Although LVOTO is classically described in patients with hypertrophic cardiomyopathy it has been reported in other conditions including septic shock, apical ballooning syndrome, myocardial infarction, respiratory failure, and post valvular surgery. It is more common in the elderly, females, and in patients with hypertension, diabetes, and chronic vascular disease because of predisposing anatomical conditions such as left ventricular hypertrophy, small left ventricle size, sigmoid septum and alterations in the positions of the aortic and mitral valve annular planes. The onset of LVOTO is largely unpredictable due to a complex interplay between preload, afterload, heart rhythm and rate in susceptible patients. The consequences of missing this treatable condition may lead to life-threatening hypotension refractory to, or exacerbated by, a further increase in inotropic support. Dynamic LVOTO should be considered in any hypotensive intensive care patient. Echocardiography is perhaps the best tool to assess LVOTO and its underlying pathophysiology in the critically ill. Detection of LVOTO is a relatively simple task using a combination of two-dimensional, M-mode and spectral Doppler imaging by an operator alert to the possible diagnosis.

Speckle tracking echocardiography in the critically ill: enticing research with minimal clinical practicality or the answer to non-invasive cardiac assessment?

Echocardiography is developing rapidly. Speckle tracking echocardiography is the latest semi-automatic tool that has potential to quantitatively describe cardiac dysfunction that may be unrecognised by conventional echocardiography. It is a non-Doppler, angle-independent, feasible and reproducible method to evaluate myocardial function in both non-critically ill and critically ill populations. Increasingly it has become a standard measure of both left and right ventricle function in specific patient groups, e.g. chemotherapy-induced cardiomyopathy or pulmonary hypertension. To date there are few studies in the critically ill, predominantly in sepsis, yet all describe dysfunction beyond standard measures. Other areas of interest include heart-lung interactions, right ventricle function and twist and torsion of the heart. A word of caution is required, however, in that speckle tracking echocardiography is far from perfect and is more challenging, particularly in the critically ill, than implied by many published studies. It takes time to learn and perform and most values are not validated, particularly in the critically ill. We should be cautious in accepting that the latest software used in cardiology cohorts will automatically be the answer in the critically ill. Even with these limitations the technology is enticing and results fascinating. We are uncovering previously undescribed dysfunction and although it currently is essentially a research-based activity, there is great promise as a clinical tool as echocardiography analysis becomes more automated, and potentially speckle tracking echocardiography could help describe cardiac function in critical illness more accurately than is possible with current techniques.

Comparison of cardiac output measurements in critically ill patients: FloTrac/Vigileo vs transthoracic Doppler echocardiography.

Measurement of cardiac output is an integral part of patient management in the intensive care unit. FloTrac/Vigileo is a continuous cardiac output monitoring device that does not need re-calibration. However its reliability has been questioned in some studies, especially involving surgical patients. In this study, we evaluated the comparability of FloTrac/Vigileo and transthoracic Doppler echocardiography in 53 critically ill patients requiring continuous cardiac output monitoring. Most of these patients had septic or cardiogenic shock. Cardiac output was measured by both FloTrac/Vigileo and transthoracic Doppler echocardiography. The bias and precision (mean and SD) between the two devices was 0.35 +/- 1.35 l/minute. The limits of agreement were -2.3 to 3.0 l/minute (%error = 49.3%). When patients with irregular heart rhythms and aortic stenosis were excluded, the bias and precision was 0.02 +/- 0.80 l/minute (n = 42). The limits of agreement were -1.55 to 1.59 l/minute (%error = 29.5%). Patient demographics (body surface area, gender and age) did not affect the bias, but there was a mild tendency for FloTrac/ Vigileo to register a higher cardiac output at high heart rates. Changes in cardiac output for two consecutive days correlated well between the two methods (r = 0.86; P < 0.001). In summary, with the exceptions of patients with irregular heart rhythms and significant aortic stenosis, FloTrac/Vigileo is clinically comparable to transthoracic Doppler echocardiography in cardiac output measurements in critically ill patients.

Endotoxin stimulated interleukin-10 production is enhanced by adenosine. Possible key to septic shock associated immune deficiency?

The aim of this bench study was to investigate whether adenosine influences secretion of interleukin-10 (IL-O) in human whole blood culture stimulated with lipopolysaccharide. Whole blood from healthy human volunteers was mixed ex vivo in 1:1 ratio with RPMI 1640 culture medium and subsequently cultured at 37 degrees C with or without adenosine (total of 120 microM added in four aliquots over two hours) in the presence or absence of 100 ng/ml lipopolysaccharide for four and eight hours, respectively. There was only a minimal IL-10 production after four hours of culture regardless of the experimental conditions. However, lipopolysaccharide stimulated whole blood cultures with added adenosine released large amounts of IL-lO after eight hours. The response was similar whether adenosine was added before (5.99 pg/ml/10(6) leucocytes) or after (10.35 microg/ml/10(6) leucocytes) stimulation with lipopolysaccharide and interindividual variation was present. In conclusion adenosine enhances lipopolysaccharide stimulated IL-10 production in whole human blood and may contribute to the IL-10 mediated immune dysfunction in sepsis.

The effects of acute fluid loading on plasma B-type natriuretic peptide levels in a septic shock patient.

A 64-year-old female patient was admitted to a general intensive care unit with sustained hypotension resulting from severe sepsis. Her admission plasma B-type natriuretic peptide was elevated (407 pg/ml), and echocardiogram displayed normal ventricular dimensions and function. The right ventricular end-diastolic diameter increased with acute fluid loading, and this coincided with a parallel increase in B-type natriuretic peptide. Subsequent fluid depletion was accompanied by a reduction in both right ventricular end-diastolic diameter and B-type natriuretic peptide. The present case indicates that acute fluid loading may alter plasma B-type natriuretic peptide levels, and highlights the importance of taking the clinical context into account when interpreting these levels.

The correlation between airborne methicillin-resistant Staphylococcus aureus with the presence of MRSA colonized patients in a general intensive care unit.

Air sampling directly onto a methicillin-resistant Staphylococcus aureus (MRSA) selective agar was performed at six locations three times weekly over a period of 32 weeks in a new, initially MRSA-free Intensive Care Unit to examine if MRSA is present in air sample cultures and, if so, whether it is affected by the number of MRSA colonized patients present. A total of 480 air samples were collected on 80 days. A total of 39/480 (8.1%) samples were found to be MRSA positive of which 24/160 (15%) positive air samples were from the single rooms, where MRSA colonised patients were isolated, and 15/320 (4.7%) were from the open bed areas. A significant correlation was found between the daily number of MRSA colonized or infected patients in the Unit and the daily number of MRSA positive air samples cultures obtained (r2=0.128; P<0.005). The frequency of positive cultures was significantly higher in the single rooms than in the open bed areas (relative risk=3.2; P<0.001). The results from one of the single rooms showed a strong correlation between the presence of MRSA patients and MRSA positive air samples (relative risk=11.4; P<0. 005). Our findings demonstrate that the presence of airborne MRSA in our unit is strongly related to the presence and number of MRSA colonized or infected patients in the Unit.

Increased B-type natriuretic peptide (BNP) level is a strong predictor for cardiac dysfunction in intensive care unit patients.

Patients admitted to an Intensive Care Unit (ICU) frequently have underlying cardiac dysfunction. Early interventions are sometimes difficult to initiate because of diagnostic uncertainty as to whether cardiac failure is present As B-type natriuretic peptide (BNP) has been shown to be increased in cardiac dysfunction, we sought to demonstrate whether BNP can be used as a screening tool for cardiac dysfunction in patients admitted to ICU. All patients admitted to a combined medical and surgical ICU over a four-week period were included in the study. BNP was measured on the point of admission using a hand-held meter. Clinicians were blinded from the measurement when diagnoses were made as to whether or not the patients had clinically significant cardiac dysfunction. Patients with cardiac dysfunction had a significantly higher level of BNP when compared to the non-cardiac dysfunction group: 516 +/- 385 pg/ml (n = 26) v 67 +/- 89 pg/ml (n = 58) (P < 0.0001) A BNP cut-off value at 144 pg/ml exhibited a 92% sensitivity, 86% specificity and 96% negative predictive value. The sensitivity improved to 96% when the analysis was confined to patients > or = 55 years. At this cut-off value, BNP is a strong predictor of cardiac dysfunction. BNP measurement offers a rapid and affordable way to screen for cardiac dysfunction in patients admitted to ICU. An increased BNP level warrants further cardiac investigations so as to implement early interventions for cardiac decompensation in ICU patients.

Cardiac tamponade in a postpartum woman with Lemierre's syndrome.

A 23-year-old primigravida with Lemierre's syndrome developed pericardial tamponade secondary to mediastinal infection and anticoagulant therapy. Intrathoracic echocardiographic diagnosis during a period of cardiac arrest led to urgent pericardiocentesis and successful resuscitation.

Transoesophageal echocardiography in the intensive care unit.

The role of transoesophageal echocardiography (TOE) in a general intensive care unit was examined by reviewing all studies performed in a major metropolitan hospital over a two-year period. TOE was performed on 53 patients where transthoracic studies were inadequate, the indications being cardiac source of embolus (13/53), thoracic aorta abnormalities (5/53), left ventricular systolic function (22/53), endocarditis (6/53), right heart pathology (2/53), pulmonary embolus (2/53), or a potentially surgical correctable lesion (3/53). Findings were categorized into three groups: confirming suspected pathology (18/53), major incidental findings (6/53), or normal (29/53). Patient management was altered, not only by the finding of positive pathology, but also after identifying normal left ventricular systolic function (14/53). Echocardiography has become an invaluable tool in the ICU setting.

Estimation of cardiac output by noninvasive echocardiographic techniques in the critically ill subject.

We evaluated the accuracy of cardiac output estimations by three transthoracic echocardiographic techniques in critically ill subjects. This study was a prospective comparison study carried out in a general intensive care unit of a teaching hospital. The subjects had a broad range of diagnoses including pulmonary embolus, cardiogenic shock, septic shock, Legionnaire's disease and perioperative myocardial infarction. All patients requiring pulmonary artery catheterization underwent echocardiographic cardiac assessment with comparison of findings to those obtained by thermodilution techniques. Nineteen studies on eighteen patients were performed, with cardiac output calculated by the two-chamber Simpson's, four-chamber Simpson's, and left ventricular outflow tract (LVOT) Doppler methods. Acceptable data was obtained in those patients without mitral regurgitation. There was good correlation between the thermodilution technique and Simpson's two-chamber method (r = 0.91), but less so with the Simpson's four-chamber method (r = 0.77). All studies were included in the LVOT Doppler method with a good correlation (r = 0.94). A plot of differences between methods using the Bland and Altman statistical method indicated that only the LVOT Doppler method demonstrated acceptable agreement with a mean of 0.2 litres/minute, standard deviation of 0.82 litres/minute and 95% limits of agreement of -1.5 to +1.9 litres/minute. We concluded that the LVOT Doppler method was the only one which demonstrated acceptable agreement between the thermodilution method and echocardiographic techniques in all critically ill patients studied.

Echocardiography assessment of left ventricular function in the critically ill.

Echocardiography is fast becoming the technique of choice for noninvasive evaluation of left ventricular function in the critically ill patient. Current technology allows for assessment of overall left ventricular performance and for diastolic and systolic function. Doppler technology has greatly enhanced the diagnostic capability of two-dimensional echocardiography. The critical care physician should be aware not only of currently available techniques, but also those which will be used in the routine care of the critically ill subject in the foreseeable future.

Australian intensive care educational links with Asian countries.

A survey examining the level of Australian Intensive Care Unit involvement in the education of Asian critical care doctors and nurses was performed. Of the 49 hospitals surveyed, 34% have ongoing links. An analysis of countries involved, proportion of medical and nursing numbers, and whether the teaching was performed in Australia or the Asian country was undertaken. The survey revealed that a high proportion of Australian Intensive Care Units are actively involved, or would consider future participation, in educational links with Asian units.

Vasopressor therapy in cardiac resuscitation.

The standard 0.5 to 1.0 mg dose of adrenaline used in cardiac resuscitation may be inadequate on the basis of theoretical and experimental evidence. Well designed clinical trials are indicated to test the hypothesis that higher doses of adrenaline could be more effective in specific subgroups of people experiencing cardiac arrest. The success in resuscitation is related to the aortic diastolic pressure and the effectiveness of adrenaline relates to its peripheral vasopressor effect. Other catecholamines such as noradrenaline may be more efficacious, as could be non-adrenergic vasopressors. Clinical studies are required, however, to evaluate these potential alternatives.