Diagnostic Adjunct Techniques in the Assessment of Hypovolemia: A Prospective Pilot Project

INTRODUCTION

Measuring the hypovolemic resuscitation end point remains a critical care challenge. Our project compared clinical hypovolemia (CH) with three diagnostic adjuncts: 1) noninvasive cardiac output monitoring (NICOM), 2) ultrasound (US) static IVC collapsibility (US-IVC), and 3) US dynamic carotid upstroke velocity (US-C). We hypothesized US measures would correlate more closely to CH than NICOM.

METHODS

Adult trauma/surgical intensive care unit patients were prospectively screened for suspected hypovolemia after acute resuscitation, excluding patients with burns, known heart failure, or severe liver/kidney disease. Adjunct measurements were assessed up to twice a day until clinical improvement. Hypovolemia was defined as: 1) NICOM: ≥10% stroke volume variation with passive leg raise, 2) US-IVC: <2.1 cm and >50% collapsibility (nonventilated) or >18% collapsibility (ventilated), 3) US-C: peak systolic velocity increase 15 cm/s with passive leg raise. Previously unknown cardiac dysfunction seen on US was noted. Observation-level data were analyzed with a Cohen's kappa (κ).

RESULTS

44 patients (62% male, median age 60) yielded 65 measures. Positive agreement with CH was 47% for NICOM, 37% for US-IVC and 10% for US-C. None of the three adjuncts correlated with CH (κ -0.045 to 0.029). After adjusting for previously unknown cardiac dysfunction present in 10 patients, no adjuncts correlated with CH (κ -0.036 to 0.031). No technique correlated with any other (κ -0.118 to 0.083).

CONCLUSIONS

None of the adjunct measurements correlated with CH or each other, highlighting that fluid status assessment remains challenging in critical care. US should assess for right ventricular dysfunction prior to resuscitation.

Near-Infrared Spectroscopy Monitoring to Detect Changes in Cerebral and Renal Perfusion During Hypovolemic Shock, Volume Resuscitation, and Vasoconstriction

INTRODUCTION

Rapidly changing hemodynamic conditions, such as uncontrolled hemorrhage and the resulting hypovolemic shock, are a common contributor to active duty military deaths. These conditions can cause cerebral desaturation, and outcomes may improve when regional cerebral oxygen saturation (CrSO2) is monitored using near-infrared spectroscopy (NIRS) and desaturation episodes are recognized and reversed. The purpose of this porcine study was to investigate the ability of NIRS monitoring to detect changes in regional cerebral and regional renal perfusion during hypovolemia, resuscitation by volume infusion, and vasoconstriction.

MATERIALS AND METHODS

Hemorrhagic shock was induced by removing blood through a central venous catheter until mean arterial pressure (MAP) was <40 mmHg. Each blood removal step was followed by a 10-minute stabilization period, during which cardiac output, blood pressure, central venous pressure, blood oxygen saturation, and CrSO2 and regional renal oxygen saturation (RrSO2) were measured. Shock was reversed using blood infusion and vasoconstriction separately until MAP returned to normal. Statistical comparisons between groups were performed using the paired t-test or the Wilcoxon signed-rank test.

RESULTS

Using volume resuscitation, both CrSO2 and RrSO2 returned to normal levels after hypovolemia. Blood pressure management with phenylephrine returned CrSO2 levels to normal, but RrSO2 levels remained significantly lower compared to the pre-hemorrhage values (P < .0001). Comparison of the percent CrSO2 as a function of MAP showed that CrSO2 levels approach baseline when a normal MAP is reached during volume resuscitation. In contrast, a significantly higher MAP was required to return to baseline CrSO2 during blood pressure management with phenylephrine (P < .0001). Evaluation of carotid blood flow and CrSO2 indicated that during induction of hypovolemia, the two measures are strongly correlated. In contrast, there was limited correlation between carotid blood flow and CrSO2 during blood infusion.

CONCLUSIONS

This study demonstrated that it is possible to restore CrSO2 by manipulating MAP with vasoconstriction, even in profound hypotension. However, MAP manipulation may result in unintended consequences for other organs, such as the kidney, if the tissue is not reoxygenated sufficiently. The clinical implications of these results and how best to respond to hypovolemia in the pre-hospital and hospital settings should be elucidated by additional studies.

Fluid therapy in the acute brain injured patient

Adequate fluid therapy in the acute brain injured (ABI) patient is essential for maintaining an adequate brain and systemic physiology and preventing intra- and extracranial complications. The target of euvolemia, implying avoidance of both hypovolemia and fluid overloading (or "hypervolemia," by definition associated with fluid extravasation leading to tissue edema) is of key importance. Primary brain injury can be aggravated by secondary brain injury and systemic deterioration through diverse pathways which can challenge appropriate fluid management, e.g. neuroendocrine and electrolyte disorders, stress cardiomyopathy (also known as cardiac stunning) and neurogenic pulmonary edema. This is an updated expert opinion aiming to provide a practical overview on fluid therapy in the ABI patient, partly based on more recent work and stressing the fact that intravenous fluids should be regarded as drugs, with their inherent potential for both benefit and (unintended) harm.

Fluid therapy for severe malaria

Fluid therapy is an important supportive measure for patients with severe malaria. Patients with severe malaria usually have normal cardiac index, vascular resistance, and blood pressure and a small degree of hypovolaemia due to dehydration. Cell hypoxia, reduced kidney function, and acidosis result from microcirculatory compromise and malarial anaemia, which reduce tissue oxygenation, not hypovolaemia. Hence, aggressive fluid loading does not correct acid-base status, enhance kidney function, or improve patient outcomes, and it risks complications such as pulmonary oedema. Individualised conservative fluid management is recommended in patients with severe malaria. Physical examination and physiological indices have limited reliability in guiding fluid therapy. Invasive measures can be more accurate than physical examination and physiological indices but are often unavailable in endemic areas, and non-invasive measures, such as ultrasound, are mostly unexplored. Research into reliable methods applicable in low-resource settings to measure fluid status and response is a priority. In this Review, we outline the current knowledge on fluid management in severe malaria and highlight research needed to optimise fluid therapy and improve survival in severe malaria.

The Intensivist's Perspective of Shock, Volume Management, and Hemodynamic Monitoring

One of the primary reasons for intensive care admission is shock. Identifying the underlying cause of shock (hypovolemic, distributive, cardiogenic, and obstructive) may lead to entirely different clinical pathways for management. Among patients with hypovolemic and distributive shock, fluid therapy is one of the leading management strategies. Although an appropriate amount of fluid administration might save a patient's life, inadequate (or excessive) fluid use could lead to more complications, including organ failure and mortality due to either hypovolemia or volume overload. Currently, intensivists have access to a wide variety of information sources and tools to monitor the underlying hemodynamic status, including medical history, physical examination, and specific hemodynamic monitoring devices. Although appropriate and timely assessment and interpretation of this information can promote adequate fluid resuscitation, misinterpretation of these data can also lead to additional mortality and morbidity. This article provides a narrative review of the most commonly used hemodynamic monitoring approaches to assessing fluid responsiveness and fluid tolerance. In addition, we describe the benefits and disadvantages of these tools.

Vancomycin prophylaxis for revision hip arthroplasty in penicillin and cephalosporin sensitive patients: Is dose adjustment necessary in accordance with blood loss and fluid replacement?

OBJECTIVE

The aims of this study were (1) to investigate the changes in the serum concentration of prophylactically administrated vancomycin in the perioperative period of revision hip arthroplasty in penicillin/cephalosporin-allergic patients, (2) to assess whether the postoperative re-administration of vancomycin is needed, and (3) to determine the relationships of vancomycin serum concentration with blood loss, body weight, and fluid replacement in such patients.

METHODS

This study consisted of 29 patients (20 females, 9 males; mean age=63.3 years; age range=45-79 years) with a history of penicillin/cephalosporin allergy undergoing revision hip arthroplasty secondary to aseptic loosening or periprosthetic fractures. Serum vancomycin levels were measured (1) before administration of vancomycin, (2) at the time of skin incision, (3) every 1,5 hours thereafter until the end of the operation, (4) during the skin closure, and (5) after three and 12 hours from the initial dosage. Data regarding body weight, amounts of intraoperative blood loss, fluid and blood replacements and postoperative wound drainage were recorded.

RESULTS

The average blood loss, fluid replacement, and drain volume were 1280.3±575.8 (500-2700) mL, 2922.6±768.8 (1700-4600) mL, and 480.2±163.7 (200-850) mL, respectively. The mean levels of serum vancomycin were 46.3±21.8 (14.1-80.7) mg/L at the time of skin incision, 17.9±4.7 (9.4-30.9) and 9.8±2.2 (4.3-13.8) mg/L after 1.5 and 3 hours from the beginning of the surgery and 5.1±1.1 (2.9-6.8)mg/L after 12th hour postoperatively. The measured vancomycin levels were below the effective serum concentrations (< 5 mg/L) for 18 patients at 12 hours the administration of the first dose. A moderate level negative correlation between the blood loss/body weight ratio and vancomycin levels was found (p=0.004, r=-0.493). Predictive ROC curve analysis resulted in determining a blood loss volume higher than 1150 ml and a blood loss/body weight ratio higher than 18,5 is significant to estimate the vancomycin level below the minimum effective serum level at 12th hour postoperatively (AUC=0.793±0.16, p=0.009, AUC=0.753) 26±0.12, p=0.025, respectively).

CONCLUSION

Evidence from this study has indicated vancomycin concentration at 12th hour is below the effective level in most patients. Thus, earlier repetitive infusion of vancomycin seems to be necessary in penicillin/cephalosporin-allergic patients undergoing revision hip arthroplasty, especially in those with high blood loss.

LEVEL OF EVIDENCE

Level III, Therapeutic Study.

Phases of fluid management and the roles of human albumin solution in perioperative and critically ill patients

OBJECTIVE

Positive fluid balance is common among critically ill patients and leads to worse outcomes, particularly in sepsis, acute respiratory distress syndrome, and acute kidney injury. Restrictive fluid infusion and active removal of accumulated fluid are being studied as approaches to prevent and treat fluid overload. Use of human albumin solutions has been investigated in different phases of restrictive fluid resuscitation, and this narrative literature review was undertaken to evaluate hypoalbuminemia and the roles of human serum albumin with respect to hypovolemia and its management.

METHODS

PubMed/EMBASE search terms were: "resuscitation," "fluids," "fluid therapy," "fluid balance," "plasma volume," "colloids," "crystalloids," "albumin," "hypoalbuminemia," "starch," "saline," "balanced salt solution," "gelatin," "goal-directed therapy" (English-language, pre-January 2020). Additional papers were identified by manual searching of reference lists.

RESULTS

Restrictive fluid administration, plus early vasopressor use, may reduce fluid balance, but in some cases fluid overload cannot be entirely avoided. Deresuscitation, with fluid actively removed through diuretics or ultrafiltration, reduces duration of mechanical ventilation and intensive care unit stay. Combining hyperoncotic human albumin solution with diuretics increases hemodynamic stability and diuresis. Hyperoncotic albumin corrects hypoalbuminemia and raises colloid osmotic pressure, limiting edema formation and potentially improving endothelial function. Serum levels of albumin relative to C-reactive protein and lactate may predict which patients will benefit most from albumin therapy.

CONCLUSIONS

Hyperoncotic human albumin solution facilitates restrictive fluid therapy and the effectiveness of deresuscitative measures. Current evidence is mostly from observational studies, and more randomized trials are needed to better establish a personalized approach to fluid management.

An evidence-based approach to nonoperative management of traumatic hemorrhagic shock in the emergency department

The management of traumatic hemorrhagic shock has evolved, with increasing emphasis on damage control resuscitation principles. Despite these advances, hemorrhage is still the leading preventable cause of death in trauma. This issue provides evidence-based recommendations for the assessment and treatment of traumatic hemorrhagic shock. Hemostatic techniques as well as correction of hemorrhagic hypovolemia and traumatic coagulopathy are presented. The safety and efficacy of practices such as resuscitative endovascular balloon occlusion of the aorta (REBOA), viscoelastic clot testing, and whole blood resuscitation are also reviewed.

Management of extracellular volume in patients with end-stage kidney disease and severe hyperglycemia

This commentary addresses volume replacement in hyperglycemic crises in patients with end-stage kidney disease (ESKD). The management of volume issues in this group of patients should not be based on guidelines for management of hyperglycemic crises, but should be individualized and based on directed patient medical history, physical examination, and imaging of the heart and lungs. A scheme for combining information from these three sources is provided.

Hypovolemic Hyponatremia

The etiology of hyponatremia is often multifactorial. The most common causes include hypovolemia from gastrointestinal (GI) or other fluid losses, thiazide diuretics, and SIAD [<citeref rid="ref1">1</citeref>]. In this chapter, we will discuss hypovolemic hyponatremia, as well as the clinical parameters that help distinguish between hypovolemic and euvolemic states. These include not only the urine [Na+] concentration but also the fractional uric acid excretion, a parameter that can be employed even when diuretics have been prescribed [<citeref rid="ref2">2</citeref>,<citeref rid="ref3">3</citeref>,<citeref rid="ref4">4</citeref>,<citeref rid="ref5">5</citeref>,<citeref rid="ref6">6</citeref>,<citeref rid="ref7">7</citeref>]. Among the common causes of hypovolemic hyponatremia are GI fluid loss, a range of endocrinopathies [<citeref rid="ref7">7</citeref>], and thiazide-induced hyponatremia, which is best considered as a distinct entity, in particular because recent data suggest that it has a genetic predisposition. Also, the discontinuation of thiazide is a key step in treatment [<citeref rid="ref2">2</citeref>,<citeref rid="ref7">7</citeref>]. The management of hypovolemic hyponatremia starts with confirming its presence and determining the underlying cause. Correction focuses on the appropriate use of isotonic fluid to effect volume repletion while avoiding an overly rapid rise in serum [Na+] concentration.

Respiratory variations in pulse pressure and photoplethysmographic waveform amplitude during positive expiratory pressure and continuous positive airway pressure in a model of progressive hypovolemia

PURPOSE

Respiratory variations in pulse pressure (dPP) and photoplethysmographic waveform amplitude (dPOP) are used for evaluation of volume status in mechanically ventilated patients. Amplification of intrathoracic pressure changes may enable their use also during spontaneous breathing. We investigated the association between the degree of hypovolemia and dPP and dPOP at different levels of two commonly applied clinical interventions; positive expiratory pressure (PEP) and continuous positive airway pressure (CPAP).

METHODS

20 healthy volunteers were exposed to progressive hypovolemia by lower body negative pressure (LBNP). PEP of 0 (baseline), 5 and 10 cmH2O was applied by an expiratory resistor and CPAP of 0 (baseline), 5 and 10 cmH2O by a facemask. dPP was obtained non-invasively with the volume clamp method and dPOP from a pulse oximeter. Central venous pressure was measured in 10 subjects. Associations between changes were examined using linear mixed-effects regression models.

RESULTS

dPP increased with progressive LBNP at all levels of PEP and CPAP. The LBNP-induced increase in dPP was amplified by PEP 10 cmH20. dPOP increased with progressive LBNP during PEP 5 and PEP 10, and during all levels of CPAP. There was no additional effect of the level of PEP or CPAP on dPOP. Progressive hypovolemia and increasing levels of PEP were reflected by increasing respiratory variations in CVP.

CONCLUSION

dPP and dPOP reflected progressive hypovolemia in spontaneously breathing healthy volunteers during PEP and CPAP. An increase in PEP from baseline to 10 cmH2O augmented the increase in dPP, but not in dPOP.

Diagnosing hypovolemia and hypervolemia: from clinical examination to modern methods

In acutely ill patients, disturbances of circulating blood volume and water homeostasis are frequently encountered. In order to choose adequate treatment strategy a well based diagnostics of these disturbance sis necessary, because fluid therapy possess the potential not only to help but also to worsen patients state. Currently we have at hand several possibilities to diagnose hypovolemia or hypervolemia: besides standard clinical assessment novel approaches as dedicated laboratory markers or sonography. Tests of fluid responsiveness are other mean how to ensure that the acutely ill patient will receive just the right amount of fluids. In this review article we will present the current view of the circulating blood volume pathophysiology as well as contemporary diagnostic tools.

Hypovolemia due to cerebral salt wasting may contribute to stroke in tuberculous meningitis

BACKGROUND

Both stroke and cerebral salt wasting (CSW) are common in tuberculous meningitis (TBM), but there is paucity of studies evaluating their combined effect.

AIM

The present study has been undertaken to evaluate the spectrum of stroke in TBM and its relation to CSW.

DESIGN

Hospital-based prospective cohort study.

METHODS

Eighty-one patients with TBM diagnosed on the basis of clinical, cerebrospinal fluid and magnetic resonance imaging (MRI) criteria were prospectively included. Stroke was diagnosed on the basis of clinical, MRI findings or both. Stroke risk factors were noted. Patients with hyponatremia were categorized into CSW and other causes. Three and 6 months outcome was defined using modified Rankin Scale (mRS) as good (<2) or poor (≥2).

RESULTS

Out of 81 patients with TBM, 32 (39.5%) had ischemic stroke. CSW was the commonest cause of hyponatremia and occurred in 34 (42%) patients. Stroke occurred in tubercular zone in 10, ischemic zone in 15 and both in 7 patients. The patients with ischemic zone infarction were older and had stroke risk factors such as diabetes mellitus, hypertension and hyperlipidemia. Out of 16 (47%) patients with CSW, 10 (62.5%) had stroke during the polyuric phase. The patients with CSW had more frequent deep white matter infarcts (P = 0.01) which were in internal border zone in 4 (40%).

CONCLUSION

In TBM, stroke occurred in 39.5% of the patients, 50% of whom had CSW. Volume contraction due to CSW may contribute to stroke.

What is the evidence base for fluid resuscitation in acute medicine?

Intravenous fluids are commonly prescribed but uncertainty remains about how to assess when fluids are required and how much to give, particularly in our multimorbid, polymedicated and ageing population. Furthermore, studies have noted that fluid resuscitation can be harmful even if clinical evidence of hypervolaemia is not present. Two recent guidelines have acknowledged a limited evidence base to guide fluid assessment. A recommended means to assess hypovolaemia includes assessment of fluid responsiveness. Fluid responsiveness is a rise in stroke volume following an increase in preload, achieved using a fluid challenge or a passive leg raise. However, the means of defining fluid responsiveness and its ability to identify patients who would benefit from fluid resuscitation is currently unclear. This review discusses the current guidelines about, and the evidence base for the provision of, intravenous fluids in the acutely unwell medical patient. It highlights how little evidence is available to guide medical practice.

Expert statement for the management of hypovolemia in sepsis

Hypovolemia is frequent in patients with sepsis and may contribute to worse outcome. The management of these patients is impeded by the low quality of the evidence for many of the specific components of the care. In this paper, we discuss recent advances and controversies in this field and give expert statements for the management of hypovolemia in patients with sepsis including triggers and targets for fluid therapy and volumes and types of fluid to be given. Finally, we point to unanswered questions and suggest a roadmap for future research.

Noninvasive monitoring of physiologic compromise in acute appendicitis: New insight into an old disease

INTRODUCTION

Physiologic compromise in children with acute appendicitis has heretofore been difficult to measure. We hypothesized that the Compensatory Reserve Index (CRI), a novel adjunctive cardiovascular status indicator, would be low for children presenting with acute appendicitis in proportion to their physiological compromise, and that CRI would rise with fluid resuscitation and surgical management of their disease.

METHODS

Ninety-four children diagnosed with acute appendicitis were monitored with a CipherOx CRI™ M1 pulse oximeter (Flashback Technologies Inc., Boulder, CO). For clarity, CRI=1 indicates supine normovolemia, CRI=0 indicates hemodynamic decompensation (systolic blood pressure<80mmHg), and CRI values between 1 and 0 indicate the proportion of volume reserve remaining before collapse. Results are presented as counts with proportion (%), or mean with 95% confidence interval (CI).

RESULTS

Mean age was 11years old (95% CI: 10-12), and 49 (52%) of the children were male. Fifty-four (57%) had nonperforated appendicitis and 40 (43%) had perforated appendicitis. Mean initial CRI was significantly higher in those with nonperforated appendicitis compared to those with perforated appendicitis (0.57, 95% CI: 0.52-0.63 vs. 0.36, 95% CI: 0.29-0.43; P<0.001). The significant differences in mean CRI values between the two groups remained throughout the course of treatment, but lost its significance at 2h after surgery (0.63, 95% CI: 0.57-0.70 vs. 0.53, 95% CI: 0.46-0.61; P=0.05).

CONCLUSION

Low CRI values in children with perforated appendicitis are indicative of their lower reserve capacity owing to peritonitis and hypovolemia. CRI offers a real-time, noninvasive adjunctive tool to monitor tolerance to volume loss in children.

LEVEL OF EVIDENCE

Study of diagnostic test; Level of evidence: Level III.

Novel Insights into the Pathogenesis and Prevention of Intradialytic Hypotension

BACKGROUND

Intradialytic hypotension (IDH) is a common complication of haemodialysis (HD) and associated with adverse outcomes, especially when a nadir definition (systolic blood pressure <90 mm Hg) is used. The pathogenesis of IDH is directly linked to the discontinuous nature of the HD treatment, in combination with patient-related factors such as age, diabetes mellitus and cardiac failure.

SUMMARY

Although the decline in blood volume due to removal of fluid by ultrafiltration is the prime mover, thermally induced reflex vasodilation compromises the haemodynamic response to hypovolemia. Recent studies have stressed the relevance of changes in tissue perfusion during HD, which may translate in long-term organ damage. Monitoring changes in tissue perfusion, for which emerging evidence becomes available, appears to have great promise in the fine-tuning of the dialysis procedure. Key Messages: While it is unlikely that IDH can be completely prevented, reduction in inter-dialytic weight gain, prevention of an increase in core temperature by adjusting the dialysate temperature and more frequent or prolonged dialysis treatment remain cornerstones in providing a more comfortable and safe treatment.

Assessment of Fluid responsiveness in the Acute Medical Patient and the Role of Echocardiography

Both hyper and hypovolaemia have been associated with poor outcomes. Assessment of fluid responsiveness is challenging in the acute medical patient, due to time constraints, limited evidence and quite often the lack of accurate assessment tools on the Acute Medicine Unit (AMU). This article explains how focused echo assessment is quick and easy to use for this purpose on the acute medical take and highlights key principles to bear in mind when assessing for hypovolaemia and whether to administer fluid therapy. The increasing familiarity with focused echo such as Focused Intensive Care Echocardiography (FICE) and Point Of Care Ultrasound (POCUS) makes extension of these skill sets to assess for fluid responsiveness a relatively straightforward next step for acute physicians.

Hypertonic saline in critical illness - A systematic review

INTRODUCTION

The optimal approach to fluid management in critically ill patients is highly debated. Fluid resuscitation using hypertonic saline was used in the past for more than thirty years, but has recently disappeared from clinical practice. Here we provide an overview on the currently available literature on effects of hypertonic saline infusion for fluid resuscitation in the critically ill.

METHODS

Systematic analysis of reports of clinical trials comparing effects of hypertonic saline as resuscitation fluid to other available crystalloid solutions. A literature search of MEDLINE and the Cochrane Controlled Clinical trials register (CENTRAL) was conducted to identify suitable studies.

RESULTS

The applied search strategy produced 2284 potential publications. After eliminating doubles, 855 titles and abstracts were screened and 40 references retrieved for full text analysis. At total of 25 scientific studies meet the prespecified inclusion criteria for this study.

CONCLUSION

Fluid resuscitation using hypertonic saline results in volume expansion and less total infusion volume. This may be of interest in oedematous patients with intravascular volume depletion. When such strategies are employed, renal effects may differ markedly according to prior intravascular volume status. Hypertonic saline induced changes in serum osmolality and electrolytes return to baseline within a limited period in time. Sparse evidence indicates that resuscitation with hypertonic saline results in less perioperative complications, ICU days and mortality in selected patients. In conclusion, the use of hypertonic saline may have beneficial features in selected critically ill patients when carefully chosen. Further clinical studies assessing relevant clinical outcomes are warranted.

The importance of albumin infusion rate for plasma volume expansion following major abdominal surgery - AIR: study protocol for a randomised controlled trial

BACKGROUND

Administration of fluids to restore normovolaemia is one of the most common therapeutic interventions performed peri-operatively and in the critically ill, but no study has evaluated the importance of infusion rate for the plasma volume-expanding effect of a resuscitation fluid. The present study is designed to test the hypothesis that a slow infusion of resuscitation fluid results in better plasma volume expansion than a rapid infusion.

METHODS/DESIGN

The study is a single-centre, assessor-blinded, parallel-group, randomised prospective study. Patients over 40 years of age admitted to the post-operative care unit after a Whipple procedure or major gynaecological surgery and presenting with signs of hypovolaemia are eligible for inclusion. Patients are randomised in a 1:1 fashion with no stratification to either rapid (30 minutes) or slow (180 minutes) infusion of 5% albumin at a dose of 10 ml/kg ideal body weight. Plasma volume is measured using 125I human serum albumin at baseline (prior to albumin infusion) as well as at 30 minutes and 180 minutes after infusion start. The primary endpoint is change in plasma volume from baseline to 180 minutes after the start of 5% albumin infusion. Secondary endpoints include the integral of plasma volume over time from baseline to 180 minutes after the start of the infusion and transcapillary escape rate of albumin (%/h) from 180 minutes to 240 minutes after the start of albumin infusion. In addition, diuresis, change in central venous oxygen saturation, lactate and blood pressure will be evaluated. A total of 70 patients will be included in the study, and the study has 80% power to detect a difference of 4 ml/kg in plasma volume expansion between the two groups.

DISCUSSION

The present study is the first clinical investigation of the importance of infusion rate for the plasma volume-expanding effect of a resuscitation fluid.

TRIAL REGISTRATION

EudraCT identifier: 2013-004446-42 . Registration date: 20 December 2013. ClinicalTrials.gov identifier: NCT02728921 . Registration date: 31 March 2016.

Utility of transthoracic echocardiography (TTE) in assessing fluid responsiveness in critically ill patients - a challenge for the bedside sonographer

Transthoracic echocardiography (TTE) has become one of the most important diagnostic tools in the treatment of critically ill patients. It allows clinicians to recognise potentially reversible life-threatening situations and is also very effective in the monitoring of the fluid status of patients, slowly substituting invasive methods in the intensive care unit. Hemodynamic assessment is based on a few static and dynamic parameters. Dynamic parameters change during the respiratory cycle in mechanical ventilation and the level of this change directly corresponds to fluid responsiveness. Most of the parameters cannot be used in spontaneously breathing patients. For these patients the most important test is passive leg raising, which is a good substitute for fluid bolus. Although TTE is very useful in the critical care setting, we should not forget the important limitations, not only technical ones but also caused by the critical illness itself. Unfortunately, this method does not allow continuous monitoring and every change in the patient's condition requires repeated examination.

Hypertonic hydroxyethyl starch solution for hypovolaemia correction following heart surgery

Background. The aim of the study was to evaluate the effect of hypertonic NaCl hydroxyethyl starch solution on haemodynamics and cardiovascular parameters in the early postoperative period in patients for correction of hypovolaemia after heart surgery. Methods. Eighty patients undergoing myocardial revascularisation at the Clinic of Cardiac Surgery of the Heart Centre (Kaunas University of Medicine) were randomly divided into two groups. The HyperHaes® group (n = 40) received 250 ml 7.2% NaCl/6% HES solution and the control Ringer's acetate group (n = 40) received placebo (500ml Ringer's acetate solution) for volume correction after the surgery. Results. After infusion of HyperHaes® solution, cardiac index increased from 2.69 (0.7) to 3.52 (0.8)l/min/m2, systemic vascular resistance index, pulmonary vascular resistance index and the gradient between central and peripheral temperature decreased, and oxygen transport parameters improved. Ringer's group patients needed more intensive infusion therapy (4050.0 (1102.2) ml in the Ringer's group, 3513.7(762.5) ml in the HyperHaes® group). During the first 24 hours postoperatively, diuresis was significantly higher in the HyperHaes® group (3640.0 (1122.9) ml and 2736.0 (900.7) ml), total fluid balance was lower in HyperHaes® group (1405.6 (1519.0) ml and 2718.3 (1508.0) ml, respectively). After the infusion of HyperHaes ® solution, no adverse events were noted. Conclusions. HyperHaes ® solution had a positive effect on haemodynamic parameters and microcirculation. Oxygen transport was more effective after HyperHaes® solution infusion. Higher diuresis, lower need for the infusion therapy for the first 24 hours and lower total fluid balance were determined in the HyperHaes® group. No adverse effects were observed after HyperHaes® solution infusion. Perfusion (2007) 22, 121—127.

Fluid Management of Severefalciparum Malaria in African Children

Most African children with severe malaria who die do so on the day of admission as a result of the complications of falciparum malaria. We highlight the value of a rapid structured triage assessment to look for emergency signs that will prioritize initial management and implementation of basic life support. This can be delivered with few resources and by non-specialist medical personnel. Reduction in case fatality can only come through the wider appreciation of the need for and application of supportive therapies to treat the life-threatening complications. Hypovolaemia has emerged as a common feature of children presenting with severe malaria complicated by acidosis. Early recognition and prompt treatment may lead to improvements in outcome. We discuss the new evidence supporting the role of hypovolaemia in severe malaria and potential treatment options whilst awaiting the results of clinical trials.

Perioperative fluid volume optimization following proximal femoral fracture

BACKGROUND

Proximal femoral fracture (PFF) is a common orthopaedic emergency that affects mainly elderly people at high risk of complications. Advanced methods for managing fluid therapy during treatment for PFF are available, but their role in reducing risk is unclear.

OBJECTIVES

To compare the safety and effectiveness of the following methods of perioperative fluid optimization in adult participants undergoing surgical repair of hip fracture: advanced invasive haemodynamic monitoring, such as transoesophageal Doppler and pulse contour analysis; a protocol using standard measures, such as blood pressure, urine output and central venous pressure; and usual care.Comparisons of fluid types (e.g. crystalloid vs colloid) and other methods of optimizing oxygen delivery, such as blood product therapies and pharmacological treatment with inotropes and vasoactive drugs, are considered in other reviews.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2015, Issue 9); MEDLINE (October 2012 to September 2015); and EMBASE (October 2012 to September 2015) without language restrictions. We ran forward and backward citation searches on identified trials. We searched ClinicalTrials.gov and the World Health Organization (WHO) International Clinical Trials Registry Platform for unpublished trials. This is an updated version of a review published originally in 2004 and updated first in 2013 and again in 2015. Original searches were performed in October 2003 and October 2012.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) in adult participants undergoing surgical treatment for PFF that compared any two of advanced haemodynamic monitoring, protocols using standard measures or usual care, irrespective of blinding, language or publication status.

DATA COLLECTION AND ANALYSIS

Two review authors assessed the impact of fluid optimization interventions on outcomes of mortality, length of hospital stay, time to medical fitness, whether participants were able to return to pre-fracture accommodation at six months, participant mobility at six months and adverse events in-hospital. We pooled data using risk ratio (RR) or mean difference (MD) for dichotomous or continuous data, respectively, on the basis of random-effects models.

MAIN RESULTS

We included in this updated review five RCTs with a total of 403 participants, and we added two new trials identified during the 2015 search. One of the included studies was found to have a high risk of bias; no trial featured all pre-specified outcomes. We found two trials for which data are awaited for classification and one ongoing trial.Three studies compared advanced haemodynamic monitoring with a protocol using standard measures; three compared advanced haemodynamic monitoring with usual care; and one compared a protocol using standard measures with usual care. Meta-analyses for the two advanced haemodynamic monitoring comparisons are consistent with both increased and decreased risk of mortality (RR Mantel-Haenszel (M-H) random-effects 0.41, 95% confidence interval (CI) 0.14 to 1.20; 280 participants; RR M-H random-effects 0.45, 95% CI 0.07 to 2.95; 213 participants, respectively). The study comparing a protocol with usual care found no difference between groups for this outcome.Three studies comparing advanced haemodynamic monitoring with usual care reported data for length of stay and time to medical fitness. There was no statistically significant difference between groups for these outcomes in the two studies that we were able to combine (MD IV fixed 0.63, 95% CI -1.70 to 2.96); MD IV fixed 0.01, 95% CI -1.74 to 1.71, respectively) and no statistically significant difference in the third study. One study reported reduced time to medical fitness when comparing advanced haemodynamic monitoring with a protocol, and when comparing protocol monitoring with usual care.The number of participants with one or more complications showed no statistically significant differences in each of the two advanced haemodynamic monitoring comparisons (RR M-H random-effects 0.83, 95% CI 0.59 to 1.17; 280 participants; RR M-H random-effects 0.72, 95% CI 0.40 to 1.31; 173 participants, respectively), nor any differences in the protocol and usual care comparison.Only one study reported the number of participants able to return to normal accommodation after discharge with no statistically significant difference between groups.There were few studies with a small number of participants, and by using the GRADE (Grades of Recommendation, Assessment, Development and Evaluation Working Group) approach, we judged the quality of the outcome evidence as low. We had included one study with a high risk of bias, but upon applying GRADE, we downgraded the quality of this outcome evidence to very low.

AUTHORS' CONCLUSIONS

Five studies including a total of 403 participants provided no evidence that fluid optimization strategies improve outcomes for participants undergoing surgery for PFF. Further research powered to test some of these outcomes is ongoing.

Compensatory Reserve for Early and Accurate Prediction of Hemodynamic Compromise: Case Studies for Clinical Utility in Acute Care and Physical Performance

BACKGROUND

Humans are able to compensate for significant loss of their circulating blood volume, allowing vital signs to remain relatively stable until compensatory mechanisms are overwhelmed. The authors present several clinical and performance case studies in an effort to demonstrate real-time measurements of an individual's reserve to compensate for acute changes in circulating blood volume. This measurement is referred to as the Compensatory Reserve Index (CRI).

METHODS

We identified seven clinical and two physical performance conditions relevant to military casualty and operational medicine as models of intravascular volume compromise. Retrospective analysis of photoplethysmogram (PPG) waveform features was used to calculate CRI, where 1 represents supine normovolemia and 0 represents hemodynamic decompensation.

RESULTS

All cases had CRI values suggestive of volume compromise (<0.6) not otherwise evident by heart rate and systolic blood pressure. CRI decreased with reduced central blood volume and increased with restored volume (e.g., fluid resuscitation).

CONCLUSION

The results from these case studies demonstrate that machine-learning techniques can be used to (1) identify a clinical or physiologic status of individuals through real-time measures of changes in PPG waveform features that result from compromise to circulating blood volume and (2) signal progression toward hemodynamic instability, with opportunity for early and effective intervention, well in advance of changes in traditional vital signs.

[The use of pre-hospital tourniquets in life-threatening extremity traumas]

Tourniquets have been used for centuries. They have been called lifesavers and "an invention of the evil one". 90.9% of deaths on the battlefields result from haemorrhage. Lessons learned du­ring the wars in Iraq and Afghanistan have developed the treat­ment given to hypovolaemic patients on the battlefield. Treating bleeding and hypovolaemia is now considered as the primary intervention. The tourniquet has proven to be an indis­pensable tool treating wounded soldiers, with little risk of complications. The tourniquet might also show to be a valuable asset in a pre-hospital urban setting.

Individual goal-directed intraoperative fluid management of initially hypovolemic patients for elective major urological surgery

BACKGROUND

The impact of different approaches to fluid management during intraoperative volume resuscitation in patients undergoing major elective surgery is poorly defined. We compared volume effectiveness of crystalloid and colloid substitution aimed to maintain the cardiac index (CI) between 2.6 and 3.8 l/min/m(2) as measured by transesophageal Doppler (TED).

METHODS

A total of 115 urological patients were enrolled in the prospective randomized trial and then randomized into 2 groups, one with volume therapy based on crystalloids (n = 57) and the other with colloids (n = 58). A TED probe was inserted and then hemodynamic optimization (therapy with Ringer's solution or hydroxyethyl starch 6 % 130/0.4 and administration of vasoactive drugs) was started according to TED variables to maintain the CI between 2.6 and 3.8 l/min/m(2).

RESULTS

We observed high incidence of CI < 2.6 l/min/m(2) after induction of anesthesia (75 %) in both groups. There were no significant differences in demographic characteristics, ASA classification, length of surgery, estimated blood loss and the CI during surgery. To maintain the CI within the requested interval, significantly different amounts of crystalloids were needed as compared to colloid (median: 5000 ml vs 1500 ml). In the CRY group, more patients were treated by vasodilatators (40.4 vs 20.7 %).

CONCLUSIONS

The study confirmed that crystalloids and colloids are effective in correcting flow-related perfusion abnormalities. The significant difference between volumes of crystalloids and colloids proved their different characteristics such as unequal distribution between compartments. The expansion of therapeutic algorithm by using vasoactive drugs allows us to avoid adverse events resulting from fluid overload (Tab. 1, Fig. 5, Ref. 35).

A rapid infusion pump driven by micro electromagnetic linear actuation for pre-hospital intravenous fluid administration

A rapid infusion pump with a maximum flow rate of 6 L/h was designed experimentally using a micro electromagnetic linear actuator, and its effectiveness was evaluated by comparing with that of a commercial Power Infuser under preset flow rates of 0.2, 2, and 6 L/h. The flow rate, air detection sensitivity, occlusion response time, quantitative determination of hemolysis, and power consumption of the infusion devices were extensively investigated using statistical analysis methods (p < 0.05). The experimental results revealed that the flow rate of the designed infusion pump was more stable and accurate, and the hemolysis was significantly less than that of the Power Infuser. The air detection sensitivity and the power consumption could be comparable to that of the Power Infuser except the occlusion response time. The favorable performance made the designed infusion pump a potential candidate for applications in pre-hospital fluid administration.

[The use of pre-hospital tourniquets in life-threatening in extremity traumas]

Tourniquets have been used for centuries. They have been called lifesavers and "an invention of the evil one". 90.9% of deaths on the battlefields result from haemorrhage. Lessons learned du-ring the wars in Iraq and Afghanistan have developed the treat-ment given to hypovolaemic patients on the battlefield. Treating bleeding and hypovolaemia is now considered as the primary intervention. The tourniquet has proven to be an indis-pensable tool treating wounded soldiers, with little risk of complications. The tourniquet might also show to be a valuable asset in a pre-hospital urban setting.

Diuretic response to colloid and crystalloid fluid loading in critically ill patients

AIMS

In the critically ill patient, fluid loading is commonly done to stabilise hemodynamics and increase diuresis, whereas the absence of diuresis may predispose to harmful overloading. The goal of the current study was to evaluate the diuretic response and determinants thereof upon crystalloid and colloid fluid loading.

SUBJECTS AND METHODS

This is a substudy on 42 clinically hypovolemic, septic or non-septic patients without acute kidney injury, who were randomly assigned, after stratification for sepsis, to a 90-min fluid loading protocol with either 0.9% saline or a colloid solution (gelatin, hydroxyethyl starch 200/0.5 or albumin). Hemodynamics, biochemical parameters and diuresis were recorded. A response was defined by an increase in diuresis of >10% during fluid loading.

RESULTS

Diuresis increased more during saline than colloid infusion, together with a decline in colloid osmotic pressure (COP) of plasma and less increase in plasma volume and global hemodynamics with saline, at similar fluid balance. Nine patients (82%) receiving saline had a diuretic response, compared to 13 patients (42%) receiving colloids (P = 0.04), and the response was not predicted by underlying condition, global hemodynamics, volume of fluid infused and COP.

CONCLUSION

In critically ill patients with clinical hypovolemia, diuresis increases more during saline than colloid fluid loading, only partly dependent of a fall in plasma COP.

Impact of reduced resuscitation fluid on outcomes of children with 10-20% body surface area scalds

'Permissive hypovolaemia' fluid regimes in adult burn care are suggested to improve outcomes. Effects in paediatric burn care are less well understood. In a retrospective audit, outcomes of children from the South West Children's Burn Centre (SWCBC) less than 16 years of age with scalds of 10-20% burn surface area (BSA) managed with a reduced volume fluid resuscitation regime (post-2007) were compared to (a) an historical local protocol (pre-2007) and (b) current regimes in burn services across England and Wales (E&W). Outcomes included length of stay per percent burn surface area (LOS/%BSA), skin graft requirement and re-admission rates. 92 SWCBC patients and 475 patients treated in 15 other E&W burn services were included. Median LOS/%BSA for patients managed with the reduced fluid regime was 0.27 days: significantly less than pre-2007 and other E&W burn services (0.54 days, 0.50 days, p<0.001). Skin grafting to achieve healing reduced post-2007 compared to pre-2007 and remains comparable with other E&W services. Re-admission rates were comparable between all groups. A reduced fluid regime has significantly shortened LOS/%BSA without compromising burn depth as measured by skin grafting to achieve healing. A prospective trial comparing permissive hypovolaemia to current regimes for moderate paediatric scald injuries would help clarify.

Volume replacement following severe postpartum hemorrhage

Severe postpartum hemorrhage (PPH) can be defined as a blood loss of more than 1500 mL to 2500 mL. While rare, severe PPH is a significant contributor to maternal mortality and morbidity in the United States and throughout the world. Due to the maternal hematologic adaptation to pregnancy, the hypovolemia resulting from hemorrhage can be asymptomatic until a large amount of blood is lost. Rapid replacement of lost fluids can mitigate effects of severe hemorrhage. Current evidence on postpartum volume replacement suggests that crystalloid fluids should be used only until the amount of blood loss becomes severe. Once a woman displays signs of hypovolemia, blood products including packed red blood cells, fresh frozen plasma, platelets, and recombinant factor VIIa should be used for volume replacement. Overuse of crystalloid fluids increases the risk for acute coagulopathy and third spacing of fluids. A massive transfusion protocol is one mechanism to provide a rapid, consistent, and evidence-based team response to this life-threatening condition.

Timing and volume of fluid administration for patients with bleeding

BACKGROUND

Treatment of haemorrhagic shock involves maintaining blood pressure and tissue perfusion until bleeding is controlled. Different resuscitation strategies have been used to maintain the blood pressure in trauma patients until bleeding is controlled. However, while maintaining blood pressure may prevent shock, it may worsen bleeding.

OBJECTIVES

To examine the effect on mortality and coagulation times of two intravenous fluid administration strategies in the management of haemorrhagic hypovolaemia, early compared to delayed administration and larger compared to smaller volume of fluid administered.

SEARCH METHODS

We searched the Cochrane Injuries Group Specialised Register, Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, Ovid MEDLINE(R), Ovid MEDLINE(R) In-Process & Other Non-Indexed Citations, Ovid MEDLINE(R) Daily and Ovid OLDMEDLINE(R), Embase Classic + Embase (OvidSP), ISI Web of Science (SCI-Expanded and CPCI-S) and clinical trials registries. We checked reference lists of identified articles and contacted authors and experts in the field. The most recent search was run on 5 February 2014.

SELECTION CRITERIA

Randomised trials of the timing and volume of intravenous fluid administration in trauma patients with bleeding. Trials in which different types of intravenous fluid were compared were excluded.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data and assessed trial quality.

MAIN RESULTS

Six trials involving a total of 2128 people were included in this review. We did not combine the results quantitatively because the interventions and patient populations were so diverse. Early versus delayed fluid administration Three trials reported mortality and two reported coagulation data.In the first trial (n = 598) the relative risk (RR) for death with early fluid administration was 1.26 (95% confidence interval (CI) 1.00 to 1.58). The weighted mean differences (WMD) for prothrombin time and partial thromboplastin time were 2.7 (95% CI 0.9 to 4.5) and 4.3 (95% CI 1.74 to 6.9) seconds, respectively.In the second trial (n = 50) the RR for death with early blood transfusion was 5.4 (95% CI 0.3 to 107.1). The WMD for partial thromboplastin time was 7.0 (95% CI 6.0 to 8.0) seconds. In the third trial (n = 1309) the RR for death with early fluid administration was 1.06 (95% CI 0.77 to 1.47). Larger versus smaller volume of fluid administration Three trials reported mortality and one reported coagulation data.In the first trial (n = 36) the RR for death with a larger volume of fluid resuscitation was 0.80 (95% CI 0.28 to 22.29). Prothrombin time and partial thromboplastin time were 14.8 and 47.3 seconds in those who received a larger volume of fluid, as compared to 13.9 and 35.1 seconds in the comparison group.In the second trial (n = 110) the RR for death with a high systolic blood pressure resuscitation target (100 mm Hg) maintained with a larger volume of fluid as compared to a low systolic blood pressure resuscitation target (70 mm Hg) maintained with a smaller volume of fluid was 1.00 (95% CI 0.26 to 3.81). In the third trial (n = 25) there were no deaths.

AUTHORS' CONCLUSIONS

We found no evidence from randomised controlled trials for or against early or larger volume of intravenous fluid administration in uncontrolled haemorrhage. There is continuing uncertainty about the best fluid administration strategy in bleeding trauma patients. Further randomised controlled trials are needed to establish the most effective fluid resuscitation strategy.

Diagnosis and management of shock in the emergency department

Shock is a state of acute circulatory failure leading to decreased organ perfusion, with inadequate delivery of oxygenated blood to tissues and resultant end-organ dysfunction. The mechanisms that can result in shock are divided into 4 categories: (1) hypovolemic, (2) distributive, (3) cardiogenic, and (4) obstructive. While much is known regarding treatment of patients in shock, several controversies continue in the literature. Assessment begins with identifying the need for critical interventions such as intubation, mechanical ventilation, or obtaining vascular access. Prompt workup should be initiated with laboratory testing (especially of serum lactate levels) and imaging, as indicated. Determining the intravascular volume status of patients in shock is critical and aids in categorizing and informing treatment decisions. This issue reviews the 4 primary categories of shock as well as special categories, including shock in pregnancy, traumatic shock, septic shock, and cardiogenic shock in myocardial infarction. Adherence to evidence-based care of the specific causes of shock can optimize a patient's chances of surviving this life-threatening condition.

[Clinical effects of packed red blood cells transfusion according to storage life and time of transfusion]

It was studied 66 males aged 39.5±5.3 years with hemorrhagic shock II degree. Gas composition of arterial and venous blood was studied twice (before and after transfusion). It was revealed that succinct transfusion of packed red blood cells (to 2 doses) with storage life to 3 days after bleeding stop and hypovolemia filling is the most effective correction of hemorrhagic shock II degree. Replacement therapy in operating room in condition of stopped bleeding and unrepaired hypovolemia is burdening factor because it does not conducive to transfer of oxygen at the tissue level and inhibits stimulation of bone marrow in response to hypoxia.

Outbreak of epidemic dropsy in Ethiopia: the clinical and therapeutic observation

INTRODUCTION

Epidemic dropsy results from ingestion of argemone oil contaminated food staffs. The oil from Argemone Mexican seeds contains toxic alkaloids called sanguinarine and dehydrosangunarine. These cause wide spread capillary dilatation, proliferation and leakages. This leads to oedema, hypovolemia and hypotension.

OBJECTIVE

To describe the socio-demographic and clinical manifestations of the patients affected with epidemic dropsy in Tikur Anbessa specialized Hospital (TASH).

METHODS

A case series study was conducted in an outbreak with unusual cases which was later diagnosed to be epidemic dropsy. Clinical evaluation of suspects was done and optimal therapy given for the complications detected and information was filled in structured format by medical residents and medial chart records review was made for occurrence of new complications in the end of 9 months.

RESULTS

A total of 164 patients were seen at TASH from 26 households, in 8 sub-cities of Addis Ababa. A wide range of age group was affected with 70% from 16 to 40 years of age. There was no case among less than 5 years of age. Females were affected more than threefold as compared to males. All the patients manifested with bilateral leg swelling and pitting oedema. It was tender in 50 (30.4%) of them while 43 (26.2%) had erythema. Tachycardia was the next common manifestation occurring in 135 (82.3%), followed by cough in 123 (75%), anaemia in 59 (36%), headache in 58 (35.4%), shortness of breathing in 52 (31.2%), hair loss in 44 (26.8%) and respiratory distress in 35 (21.3%). Abdominal pain, hepatomegally, nausea and vomiting were also seen. There was abnormality in the chest X-ray of 31 (27.2%). Hair loss, tingling and burning extremities, difficulty of standing, hyperpigmentation, pruritic rash and eye symptoms were observed lately during follow up. Five of the patients died while in hospital care due to acute respiratory distress syndrome (ARDS).

CONCLUSIONS

The commonest clinical manifestation in our patients is bilateral leg swelling which is similar to other outbreaks of epidemic dropsy elsewhere. The mortality rate is also comparable with other series but all cases died by ARDS in our series which is unusual in other reports. As this is the first reported epidemics in Ethiopia the findings will create awareness of clinical features of epidemic dropsy among clinicians, and therefore, helps for diagnoses of similar problems in the future.

Perioperative fluid volume optimization following proximal femoral fracture

BACKGROUND

Proximal femoral fracture (PFF) is a common orthopaedic emergency, affecting mainly elderly people at high risk of complications. Advanced methods for managing fluid therapy during treatment for PFF are available, but their role in reducing risk is unclear.

OBJECTIVES

To compare the safety and effectiveness of different methods of perioperative fluid optimization in adult participants undergoing surgical repair of hip fracture. We considered the following methods: advanced invasive haemodynamic monitoring, such as transoesophageal Doppler and pulse contour analysis; a protocol using standard measures, such as blood pressure, urine output and central venous pressure; and usual care.Comparisons of fluid types (e.g. crystalloid vs colloid) and other methods of optimizing oxygen delivery, such as blood product therapies and pharmacological treatment with inotropes and vasoactive drugs, are considered elsewhere.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2012, Issue 9); MEDLINE (1966 to October 2012); and EMBASE (1980 to October 2012) without language restrictions. We ran forward and backward citation searches on identified trials. We contacted authors and searched ClinicalTrials.gov and the WHO International Clinical Trials Registry Platform for unpublished trials. This is an updated version of a review published in 2004. The original search was performed in October 2003.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) in adult participants undergoing surgical treatment for PFF, which compared any two of advanced haemodynamic monitoring, protocols using standard measures or usual care, irrespective of blinding, language or publication status.

DATA COLLECTION AND ANALYSIS

Two review authors assessed the impact of fluid optimization interventions on outcomes of mortality, length of hospital stay, return of participant to pre-fracture accommodation and mobility at six months and adverse events in hospital. We pooled data using risk ratio or mean difference for dichotomous or continuous data, respectively, based on random-effects models.

MAIN RESULTS

We included three RCTs with a total of 200 participants. One of these included studies was found to have a high risk of bias; no trial featured all pre-specified outcomes. We found one trial for which data are awaited for classification and two ongoing trials. One included study with low risk of bias found that compared with usual care, time to medical fitness for discharge was shorter with the use of advanced haemodynamic monitoring (mean reduction 6.20 days, 95% CI 2.3 to 10.1 days; 59 participants, one trial) and with the use of protocols that apply standard measures (mean reduction 3.9 days, 95% CI 0.75 to 7.05; 57 participants, one trial). Our results are consistent with both increased and decreased risk of mortality and adverse events in participants receiving the intervention. No data for other outcomes were available. Our results are limited by the quantity of available data.

AUTHORS' CONCLUSIONS

Three studies considering a total of 200 participants reveal an absence of evidence that fluid optimization strategies improve outcomes for participants undergoing surgery for PFF. Length of hospital stay may be improved, but lack of good quality data leaves uncertainty. Further research powered to test some of these outcomes is ongoing.

Variable assessment of the circulation in intensive care unit patients with shock

INTRODUCTION

Circulatory failure is frequent in intensive care unit (ICU) patients and is associated with a high mortality and morbidity. There is no current consensus on which parameters best evaluate circulatory failure, and clinical practice regarding haemodynamic assessment is unknown. This study describes current clinical practice regarding circulatory assessment in ICU patients with shock.

MATERIAL AND METHODS

This was a prospective, observational cohort study conducted in a university hospital ICU over a four-month period. Doctors working in the ICU were divided into two groups: trainees and specialists. They registered their circulatory assessments of consecutive patients with shock. The parameters included type of shock, kind of parameters used (markers of hypoperfusion, hypovolaemia and flow), which parameter was considered to be most important and the clinical action taken.

RESULTS

A total of 23 doctors performed 210 patient assessments, which was equivalent to a median of eight (interquartile range: 5-14) per doctor. Trainees used six (5-8) parameters compared with five (3-6) parameters per assessment among specialists (p < 0.01). Mean arterial pressure (MAP) was the most frequently assessed parameter (n = 178) and both specialist (in 23% of assessments) and trainees (30%) considered MAP to be the most important parameter. Hypoperfusion markers were assessed in 99% of the cases, and a marker of hypovolaemia was also assessed in 83% (95% confidence interval (CI) 78-88) of these cases. Fluid was the most frequent clinical action taken, and was given after 150 assessments, but a marker of hypovolaemia was not assessed in 13% (95% CI 9-20) of these situations. Trainees assessed heart rate (76% versus 54%; p < 0.01), diastolic (45% versus 28%, p < 0.01) and systolic blood pressure (70% versus 46%; p < 0.01) and central venous oxygen saturation (63% versus 35%; p < 0.01) more frequently than specialists.

CONCLUSION

MAP was the most frequently used parameter and fluid the most frequently given treatment by ICU doctors assessing patients with shock. The study indicates that assessment of hypoperfusion leads to the use of a marker of hypovolaemia, but in some cases fluid was given without this assessment. The haemodynamic assessment differed between ICU specialists and trainees.

FUNDING

Righospitalet's Research Council supported the study.

TRIAL REGISTRATION

not relevant.

[Impact of red blood cells transfusion on upper gastrointestinal bleeding]

Upper gastrointestinal bleeding is a major digestive emergency. The compensation of hypovolemia represents the cornerstone of the initial treatment, according to international recommendations. In contrast, use of red blood cells transfusion and target hemoglobin vary considerably across different centers. The real impact of blood transfusions on the rate of rebleeding and mortality is still unknown. However, several studies suggest that transfusion may have a deleterious effect in patients with hemodynamically stable condition during upper gastrointestinal bleeding, promoting recurrent bleeding.

Diagnosis and management of hyponatremia in cancer patients

Hyponatremia, a common electrolyte abnormality in oncology practice, may be a negative prognostic factor in cancer patients based on a systematic analysis of published studies. The largest body of evidence comes from small-cell lung cancer (SCLC), for which hyponatremia was identified as an independent risk factor for poor outcome in six of 13 studies. Hyponatremia in the cancer patient is usually caused by the syndrome of inappropriate antidiuretic hormone (SIADH), which develops more frequently with SCLC than with other malignancies. SIADH may be driven by ectopic production of arginine vasopressin (AVP) by tumors or by effects of anticancer and palliative medications on AVP production or action. Other factors may cause hypovolemic hyponatremia, including diarrhea and vomiting caused by cancer therapy. Hyponatremia may be detected on routine laboratory testing before or during cancer treatment or may be suggested by the presence of mostly neurological symptoms. Treatment depends on several factors, including symptom severity, onset timing, and extracellular volume status. Appropriate diagnosis is important because treatment differs by etiology, and choosing the wrong approach can worsen the electrolyte abnormality. When hyponatremia is caused by SIADH, hypertonic saline is indicated for acute, symptomatic cases, whereas fluid restriction is recommended to achieve a slower rate of correction for chronic asymptomatic hyponatremia. Pharmacological therapy may be necessary when fluid restriction is insufficient. The orally active, selective AVP receptor 2 (V(2))-receptor antagonist tolvaptan provides a mechanism-based option for correcting hyponatremia caused by SIADH or other conditions with inappropriate AVP elevations. By blocking AVP effects in the renal collecting duct, tolvaptan promotes aquaresis, leading to a controlled increase in serum sodium levels.

[Nephrotic crisis--an urgent condition in patients with nephrotic syndrome]

The lecture considers mechanisms of potassium and water retention underlying nephrotic syndrome, clinical differences between hypo- and hypervolemic variants of nephrotic syndrome, risk factors of nephrotic crisis and its clinical symptoms, current approaches to its treatment.

Interpreting lactate measurement in critically ill horses: diagnosis, treatment, and prognosis

In hospitalized horses, hypovolemia and the resulting decrease in tissue perfusion is the most common cause of hyperlactatemia. Therefore, measurement of blood lactate concentration can be a useful tool for guiding fluid therapy. Similarly, measuring blood lactate concentration can be used to assess the need for and adequacy of transfusions in horses receiving whole blood. Inflammatory leukocytes within closed body cavities consume glucose and produce lactate. Simultaneous measurement of blood lactate concentration and lactate concentration of peritoneal, pleural, or synovial fluid has been used to help differentiate septic from nonseptic effusions. A fluid lactate concentration higher than the blood lactate concentration provides evidence for a bacterial cause of the effusion. In horses evaluated for colic, a peritoneal lactate concentration higher than the simultaneously measured blood lactate concentration is indicative of intestinal strangulation and ischemia. Veterinary studies have suggested that serial blood lactate measurements might be a more useful prognostic indicator than a single lactate measurement. In hospitalized adult horses and foals, blood lactate concentration is higher at all time points in nonsurvivors compared with survivors, although the differences tend to be subtle. Measuring the rate at which lactate concentrations return to normal might also prove useful in equine medicine, but this requires further investigation.