Continuous passive paracentesis versus large-volume paracentesis in the prevention and treatment of intra-abdominal hypertension in the critically ill cirrhotic patient with ascites (COPPTRIAHL): study protocol for a randomized controlled trial

BACKGROUND

Critically ill patients with cirrhosis and ascites are at high risk for intra-abdominal hypertension (IAH) which increases mortality. Clinical guidelines recommend maintaining intra-abdominal pressure (IAP) below 16 mmHg; nonetheless, more than three quarters of critically ill patients with cirrhosis develop IAH during their first week of ICU stay. Standard-of-care intermittent large-volume paracentesis (LVP) relieves abdominal wall tension, reduces IAP, optimizes abdominal perfusion pressure, and is associated with short-term improvement in renal and pulmonary dysfunction. However, there is no evidence of the superiority of different paracentesis strategies in the prevention and treatment of IAH in critically ill patients with cirrhosis. This trial aims to compare the outcomes of continuous passive paracentesis versus LVP in the prevention and treatment of IAH in patients with cirrhosis and ascites.

METHODS

An investigator-initiated, open label, randomized controlled trial, set in a general ICU specialized in liver disease, was initiated in August 2022, with an expected duration of 36 months. Seventy patients with cirrhosis and ascites will be randomly assigned, in a 1:1 ratio, to receive one of two methods of therapeutic paracentesis. A stratified randomization method, with maximum creatinine and IAP values as strata, will homogenize patient baseline characteristics before trial group allocation, within 24 h of admission. In the control group, LVP will be performed intermittently according to clinical practice, with a maximum duration of 8 h, while, in the intervention group, continuous passive paracentesis will drain ascitic fluid for up to 7 days. The primary endpoint is serum creatinine concentration, and secondary endpoints include IAP, measured creatinine clearance, daily urine output, stage 3 acute kidney injury and multiorgan dysfunction assessed at day 7 after enrollment, as well as 28-day mortality rate and renal replacement therapy-free days, and length-of-stay. Prespecified values will be used in case of renal replacement therapy or, beforehand ICU discharge, liver transplant and death. Safety analysis will include paracentesis-related complication rate and harm. Data will be analyzed with an intention-to-treat approach.

DISCUSSION

This is the first trial to compare the impact of different therapeutic paracentesis strategies on organ dysfunction and outcomes in the prevention and treatment of IAH in critically ill patients with cirrhosis and ascites.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04322201 . Registered on 20 December 2019.

Abdominal perfusion pressure in critically ill cirrhotic patients: a prospective observational study

In critical patients, abdominal perfusion pressure (APP) has been shown to correlate with outcome. However, data from cirrhotic patients is scarce. We aimed to characterize APP in critically ill cirrhotic patients, analyze the prevalence and risk factors of abdominal hypoperfusion (AhP) and outcomes. A prospective cohort study in a general ICU specialized in liver disease at a tertiary hospital center recruited consecutive cirrhotic patients between October 2016 and December 2021. The study included 101 patients, with a mean age of 57.2 (± 10.4) years and a female gender proportion of 23.5%. The most frequent etiology of cirrhosis was alcohol (51.0%), and the precipitant event was infection (37.3%). ACLF grade (1-3) distribution was 8.9%, 26.7% and 52.5%, respectively. A total of 1274 measurements presented a mean APP of 63 (± 15) mmHg. Baseline AhP prevalence was 47%, independently associated with paracentesis (aOR 4.81, CI 95% 1.46-15.8, p = 0.01) and ACLF grade (aOR 2.41, CI 95% 1.20-4.85, p = 0.01). Similarly, AhP during the first week (64%) had baseline ACLF grade (aOR 2.09, CI 95% 1.29-3.39, p = 0.003) as a risk factor. Independent risk factors for 28-day mortality were bilirubin (aOR 1.10, CI 95% 1.04-1.16, p < 0.001) and SAPS II score (aOR 1.07, CI 95% 1.03-1.11, p = 0.001). There was a high prevalence of AhP in critical cirrhotic patients. Abdominal hypoperfusion was independently associated with higher ACLF grade and baseline paracentesis. Risk factors for 28-day mortality included clinical severity and total bilirubin. The prevention and treatment of AhP in the high-risk cirrhotic patient is prudential.

Biosurfactants: Sustainable and Versatile Molecules

Biosurfactants are amphipathic molecules produced by plants, animals, and microorganisms, that present emulsifying properties and may act reducing surface and interfacial tensions. When compared to synthetic surfactants, these biological analogues have high biodegradability potential, and may be produced from renewable raw materials within overall biotechnological processes involving low generation of residues. The production and application of microbial surfactants have been recently considered in several industrial sectors, as these low toxicity versatile compounds find applications in food, pharmaceutical, cosmetic, and petrochemical products, in nanotechnology and agriculture, and in the bioremediation of xenobiotic-contaminated areas. Herein, the main conceptual aspects and physicochemical properties, as well as the classifications of biosurfactants according to their origin and their chemical structures, are addressed. The production of microbial biosurfactants through sustainable processes are also described, with particular focus on new applications and on the increasing relevance of such bioproducts for the sustainable development of modern society.

Intra-abdominal hypertension and abdominal compartment syndrome in the critically ill liver cirrhotic patient-prevalence and clinical outcomes. A multicentric retrospective cohort study in intensive care

Background

Liver cirrhosis and ascites are risk factors for intra-abdominal hypertension (IAH) and abdominal compartment syndrome (ACS); however, data is scarce. We aimed to determine the prevalence of IAH/ACS in a population of critically ill cirrhotic patients with acute medical illness in intensive care and to assess for risk factors and clinical outcomes.

Methods

This was a multicentric retrospective cohort study including two general ICUs and pooled data from a multicentric study between January 2009 and October 2019.

Results

A total of 9,345 patients were screened, and 95 were included in the analysis. Mean age was 56.7±1.3 years, and 79% were male. Liver cirrhosis etiology included alcohol in 45.3% and alcohol plus hepatitis C virus in 9.5%. Precipitating events included infection in 26% and bleeding in 21% of cases. Mean severity score MELD and SAPS II were 26.2±9.9 and 48.5±15.3, respectively, at ICU admission. The prevalence of IAH and ACS was respectively 82.1% and 23.2% with a mean value of maximum IAP of 16.0±5.7 mmHg and IAH grades: absent 17.9%, I 26.3%, II 33.7%, III 17.9%, and IV 4.2%. Independent risk factors for IAH were alcoholic cirrhosis (p = 0.01), West-Haven score (p = 0.01), and PaO2/FiO2 ratio (p = 0.02); as well as infection (p = 0.048) for ACS. Overall, 28-day mortality was 52.6% associated with higher IAP and ACS, and independent risk factors were MELD (p = 0.001), white blood cell count (p = 0.03), PaO2/FiO2 ratio (p = 0.03), and lactate concentration (p = 0.04) at ICU admission.

Conclusions

This study demonstrates a very high prevalence of IAH/ACS in the critically ill cirrhotic patient in intensive care. Increased IAP and ACS were associated with severity of disease and adverse outcomes and independent risk factors for IAH were alcoholic cirrhosis, hepatic encephalopathy and PO2/FiO2 ratio, as well as infection for ACS. Early diagnosis, prevention, and treatment of IAH/ACS might improve outcome in critically ill cirrhotic patients.

Approach to the liver transplant early postoperative period: an institutional standpoint

The liver transplant program in our center started in 1992, and post-liver transplant patients are still admitted to the intensive care unit. For the intensive care physician, a learning curve started then, skills were acquired, and a specific practice was established. Throughout this time, several concepts changed, improving the care of these patients. The practical approach varies between liver transplant centers, according to local specificities. Hence, we wanted to present our routine practice to stimulate the debate between dedicated teams, which can allow the introduction of new ideas and potentially improve each local standard of care.

Gene Silencing using siRNA for Preventing Liver Ischaemia-Reperfusion Injury

Background:

Ischaemia-reperfusion injury (IRI), a major complication occurring during organ transplantation, involves an initial ischemia insult, due to loss of blood supply, followed by an inflammation-mediated reperfusion injury. A variety of molecular targets and pathways involved in liver IRI have been identified. Gene silencing through RNA interference (RNAi) by means of small interference RNA (siRNA) targeting mediators of IRI is a promising therapeutic approach.

Objective:

This study aims at reviewing the use of siRNAs as therapeutic agents to prevent IRI during liver transplantation.

Method:

We review the crucial choice of siRNA targets and the advantages and problems of the use of siRNAs.

Results:

We propose possible targets for siRNA therapy during liver IRI. Moreover, we discuss how drug delivery systems, namely liposomes, may improve siRNA therapy by increasing siRNA stability in vivo and avoiding siRNA off-target effects.

Conclusion:

siRNA therapeutic potential to preclude liver IRI can be improved by a better knowledge of what molecules to target and by using more efficient delivery strategies.

Therapeutic activity of superoxide dismutase-containing enzymosomes on rat liver ischaemia-reperfusion injury followed by magnetic resonance microscopy

Liver ischaemia-reperfusion injury (IRI) may occur during hepatic surgery and is unavoidable in liver transplantation. Superoxide dismutase enzymosomes (SOD-enzymosomes), liposomes where SOD is at the liposomal surface expressing enzymatic activity in intact form without the need of liposomal disruption, were developed with the aim of having a better insight into its antioxidant therapeutic outcome in IRI. We also aimed at validating magnetic resonance microscopy (MRM) at 7T as a tool to follow IRI. SOD-enzymosomes were characterized and tested in a rat ischaemia-reperfusion model and the therapeutic outcome was compared with conventional long circulating SOD liposomes and free SOD using biochemical liver injury biomarkers, histology and MRM. MRM results correlated with those obtained using classical biochemical biomarkers of liver injury and liver histology. Moreover, MRM images suggested that the therapeutic efficacy of both SOD liposomal formulations used was related to prevention of peripheral biliary ductular damage and disrupted vascular architecture. Therefore, MRM at 7T is a useful technique to follow IRI. SOD-enzymosomes were more effective than conventional liposomes in reducing liver ischaemia-reperfusion injury and this may be due to a short therapeutic window.

Acute-on-Chronic Liver Failure: A Portuguese Single-Center Reference Review

Acute-on-chronic liver failure (ACLF) is a syndrome characterized by an acute deterioration of a patient with cirrhosis, frequently associated with multi-organ failure and a high short-term mortality rate. We present a retrospective study that aims to characterize the presentation, evolution, and outcome of patients diagnosed with ACLF at our center over the last 3 years, with a comparative analysis between the group of patients that had ACLF precipitated by infectious insults of bacterial origin and the group of those with ACLF triggered by a nonbacterial infectious insult; the incidence of acute kidney injury and its impact on the prognosis of ACLF was also analyzed. Twenty-nine patients were enrolled, the majority of them being male (89.6%), and the mean age was 53 years. Fourteen patients (48.3%) developed ACLF due to a bacterial infectious event, and 9 of them died (64.2%, overall mortality rate 31%); however, no statistical significance was found (p < 0.7). Of the remaining 15 patients (51.7%) with noninfectious triggers, 11 died (73.3%, overall mortality rate 37.9%); again there was no statistical significance (p < 0.7). Twenty-four patients (83%) developed acute kidney injury (overall mortality rate 65.5%; p < 0.022) at the 28-day and 90-day follow-up. Twelve patients had acute kidney injury requiring renal replacement therapy (41.37%; overall mortality rate 37.9%; p < 0.043). Hepatic transplant was performed in 3 patients, with a 100% survival at the 28-day and 90-day follow-up (p < 0.023). Higher grades of ACLF were associated with increased mortality (p < 0.02; overall mortality 69%).

Conclusions

ACLF is a heterogeneous syndrome with a variety of precipitant factors and different grades of extrahepatic involvement. Most cases will have some degree of renal dysfunction, with an increased risk of mortality. Hepatic transplant is an efficient form of therapy for this syndrome.

Acute liver failure: An up-to-date approach

Acute liver failure is a rare but potentially devastating disease. Throughout the last few decades, acute liver failure outcomes have been improving in the context of the optimized overall management. This positive trend has been associated with the earlier recognition of this condition, the improvement of the intensive care unit management, and the developments in emergent liver transplantation. Accordingly, we aimed to review the current diagnostic and therapeutic approach to this syndrome, especially in the intensive care unit setting.

Clinical outcomes and genetic expression profile in human liver graft dysfunction during ischemia/reperfusion injury

INTRODUCTION

This study aims to compare the molecular gene expression during ischemia reperfusion injury. Several surgical times were considered: in the beginning of the harvesting (T0), at the end of the cold ischemia period (T1), and after reperfusion (T2) and compared with graft dysfunction after liver transplant (OLT).

METHODS

We studied 54 patients undergoing OLT. Clinical, laboratory data, and histologic data (Suzuki classification) as well as the Survival Outcomes Following Liver Transplantation (SOFT) score were used and compared with the molecular gene expression of the following genes: Interleukin (IL)-1b, IL-6, tumor necrosis factor-α, perforin, E-selectin (SELE), Fas-ligand, granzyme B, heme oxygenase-1, and nitric oxide synthetase.

RESULTS

Fifteen patients presented with graft dysfunction according to SOFT criteria. No relevant data were obtained by comparing the variables graft dysfunction and histologic variables. We observed a statistically significant relation between SELE at T0 (P = .013) and IL-1β at T0 (P = .028) and early graft dysfunction.

CONCLUSIONS

We conclude that several genetically determined proinflammatory expressions may play a critical role in the development of graft dysfunction after OLT.

Three-dimensional co-culture of human hepatocytes and mesenchymal stem cells: improved functionality in long-term bioreactor cultures

The development of human cell models that can efficiently restore hepatic functionality and cope with the reproducibility and scalability required for preclinical development poses a significant effort in tissue engineering and biotechnology. Primary cultures of human hepatocytes (HHs), the preferred model for in vitro toxicity testing, dedifferentiate and have short-term viability in two-dimensional (2D) cultures. In this study, hepatocytes isolated from human liver tissue were co-cultured with human bone marrow mesenchymal stem cells (BM-MSCs) as spheroids in automated, computer-controlled, stirred-tank bioreactors with perfusion operation mode. A dual-step inoculation strategy was used, resulting in an inner core of parenchymal liver tissue with an outer layer of stromal cells. Hepatocyte polarization and morphology as well as the mesenchymal phenotype of BM-MSCs were maintained throughout the culture period and the crosstalk between the two cell types was depicted. The viability, compact morphology and phenotypic stability of hepatocytes were enhanced in co-cultures in comparison to monocultures. Gene expression of phase I and II enzymes was higher and CYP3A4 and CYP1A2 activity was inducible until week 2 of culture, being applicable for repeated-dose toxicity testing. Moreover, the excretory activity was maintained in co-cultures and the biosynthetic hepatocellular functions (albumin and urea secretion) were not affected by the presence of BM-MSCs. This strategy might be extended to other hepatic cell sources and the characterization performed brings knowledge on the interplay between the two cell types, which may be relevant for therapeutic applications. Copyright © 2015 John Wiley & Sons, Ltd.

Prophylactic use of liposomal amphotericin B in preventing fungal infections early after liver transplantation: a retrospective, single-center study

In this study the authors evaluated the efficacy of prophylaxis with liposomal amphotericin B (L-AmB) in the incidence of fungal infections (FI) during the first 3 months after liver transplant (LT). The study was retrospective and accessed a 4-year period from 2008 to 2011. All patients who died in the first 48 hours after LT were excluded. Patients were divided by the risk groups for FI: Group 1, high-risk (at least 1 of the following conditions: urgent LT; serum creatinine >2 mg/dL; early acute kidney injury [AKI] after LT; retransplantation; surgical exploration early post-LT; transfused cellular blood components [>40 U]); and Group 2, low-risk patients. Group 1 patients were further separated into those who received antifungal prophylaxis with L-AmB and those who did not. Prophylaxis with L-AmB consisted of intravenous administration of L-AmB, 100 mg daily for 14 days. Four hundred ninety-two patients underwent LT; 31 died in the first 48 hours after LT. From the remaining 461 patients, 104 presented with high-risk factors for FI (Group 1); of these, 66 patients received antifungal prophylaxis and 38 did not. In this group 8 FI were observed, 5 in patients without antifungal prophylaxis (P = .011). Three more FI were identified in Group 2. By logistic regression analysis, the categorical variable high-risk group was independently related to the occurrence of invasive FI (P = .006). We conclude that prophylaxis with L-AmB after LT was effective in reducing the incidence of FI. No influence on mortality was detected.

Is there a relationship between intraoperative hemodynamic instability and calcineurin inhibitor-related toxicity, early after liver transplantation? A single-center observational study

This study evaluated the relationship between intraoperative hemodynamic instability (IOHI) and the development of calcineurin inhibitor (CNI) toxicity in the early postoperative period after liver transplantation (LT). Eighty-two patients were enrolled during a 1-year period and a 3-month follow-up. IOHI, requiring continuous infusion of vasopressors, was observed in 31 patients (38%, group 1; control group 2, n = 51). Acute kidney injury (AKI) developed in 28 patients (52% in group 1 vs 24% in group 2, P = .02), and CNI-related neurotoxicity (CNI-NT) in 26 (48% in group 1 vs 22% in group 2, P = .03). Group 1 patients received mainly deceased donor grafts (87% vs 57% in group 2, P < .001). An independent association between IOHI and CNI-NT (P = .029) and AKI (P = .016) was observed. The receiver-operator characteristic curve revealed an area under the curve of 0.63 for IHI (sensitivity 56%; specificity 75%) and 0.65 for AKI (sensitivity 56%; specificity 70.2%). In conclusion, patients undergoing LT with IOHI may be more prone to developing CNI-NT and AKI in the early postoperative period.

Superoxide dismutase enzymosomes: carrier capacity optimization, in vivo behaviour and therapeutic activity

PURPOSE

A strategy not usually used to improve carrier-mediated delivery of therapeutic enzymes is the attachment of the enzymes to the outer surface of liposomes. The aim of our work was to design a new type of enzymosomes with a sufficient surface-exposed enzyme load while preserving the structural integrity of the liposomal particles and activity of the enzyme.

METHODS

The therapeutic antioxidant enzyme superoxide dismutase (SOD) was covalently attached to the distal terminus of polyethylene glycol (PEG) polymer chains, located at the surface of lipid vesicles, to obtain SOD-enzymosomes.

RESULTS

The in vivo fate of the optimized SOD-enzymosomes showed that SOD attachment at the end of the activated PEG slightly reduced the residence time of the liposome particles in the bloodstream after IV administration. The biodistribution studies showed that SOD-enzymosomes had a similar organ distribution profile to liposomes with SOD encapsulated in their aqueous interior (SOD-liposomes). SOD-enzymosomes showed earlier therapeutic activity than both SOD-liposomes and free SOD in rat adjuvant arthritis. SOD-enzymosomes, unlike SOD-liposomes, have a therapeutic effect, decreasing liver damage in a rat liver ischemia/reperfusion model.

CONCLUSIONS

SOD-enzymosomes were shown to be a new and successful therapeutic approach to oxidative stress-associated inflammatory situations/diseases.

Transthyretin proteins regulate angiogenesis by conferring different molecular identities to endothelial cells

Familial amyloidotic polyneuropathy (FAP) has a high prevalence in Portugal, and the most common form of hereditary amyloidosis is caused by an amyloidogenic variant of transthyretin (TTR) with a substitution of methionine for valine at position 30 (V30M). Until now, the available efficient therapy is liver transplantation, when performed in an early phase of the onset of the disease symptoms. However, transplanted FAP patients have a significantly higher incidence of early hepatic artery thrombosis compared with non-FAP transplanted patients. Because FAP was described as an independent risk factor for early hepatic artery thrombosis, more studies to understand the underlying mechanisms involved in this outcome are of the utmost importance. Knowing that the liver is the major site for TTR production, we investigated the biological effects of TTR proteins in the vasculature and on angiogenesis. In this study, we identified genes differentially expressed in endothelial cells exposed to the WT or V30M tetramer. We found that endothelial cells may acquire different molecular identities when exposed to these proteins, and consequently TTR could regulate angiogenesis. Moreover, we show that V30M decreases endothelial survival by inducing apoptosis, and it inhibits migration. These findings provide new knowledge that may have critical implications in the prevention of early hepatic artery thrombosis in FAP patients after liver transplantation.

The evolving concepts of haemodynamic support: from pulmonary artery catheter to echocardiography and theragnostics

Echocardiography is a non-invasive tool, aimed towards the anatomical and functional characterization of the heart. In Intensive Care it is considered nowadays as a necessary tool for patient evaluation. However, the information obtained using echocardiography is not the same as provided by other means, namely the invasive ones. In recent years there has been a significant evolution in the general concepts of haemodynamic support for the critically ill patient. In this new environment, echocardiography has gained particular relevance. In this text the new positioning of echocardiography in the light of the new concepts for hemodynamic support is described, as well as, the need for a specific formative program directed towards Intensive Care physicians. A new generation of biomarkers can also add relevant information and start a new era in haemodynamic support. They may help to further characterize the disease process, identifying patients at risk, as well as, characterize specific organ failure as well as monitoring therapy.

The role of transesophageal echocardiography in the intraoperative period

The goal of hemodynamic monitoring and management during major surgery is to guarantee adequate organ perfusion, a major prerequisite for adequate tissue oxygenation and thus, end-organ function. Further, hemodynamic monitoring should serve to prevent, detect, and to effectively guide treatment of potentially life-threatening hemodynamic events, such as severe hypovolemia due to hemorrhage, or cardiac failure. The ideal monitoring device does not exist, but some conditions must be met: it should be easy and operator-independently to use; it should provide adequate, reproducible information in real time. In this review we discuss in particular the role of intraoperative use of transesophageal echocardiography (TOE). Although TOE has gained special relevance in cardiac surgery, its role in major non cardiac surgery is still to be determined. We particularly focus on its ability to provide measurements of cardiac output (CO), and its role to guide fluid therapy. Within the last decade, concepts oriented on optimizing stroke volume and cardiac output mainly by fluid administration and guided by continuous monitoring of cardiac output or so called functional parameters of cardiac preload gained particular attention. Although they are potentially linked to an increased amount of fluid infusion, recent data give evidence that such pre-emptive concepts of hemodynamic optimization result in a decrease in morbidity and mortality. As TOE allows a real time direct visualization of cardiac structures, other potentially important advantages of its use also outside the cardiac surgery operation room can be postulated, namely the ability to evaluate the anatomical and functional integrity of the left and the right heart chambers. Finally, a practical approach to TOE monitoring is presented, based on a local experience.

Domino versus deceased donor liver transplantation: association with early graft function and perioperative bleeding

This study sought to evaluate the potential impact of domino liver transplantation (DLT) on initial graft function and early postoperative outcome in patients with cirrhosis in a Portuguese liver transplantation center. A retrospective comparative analysis was performed between 77 domino recipients (from familial amyloidotic polyneuropathy donors) and 91 deceased donor recipients, all submitted to primary elective whole liver transplantation, using the piggyback technique, in a 42-month period. Outcome parameters included graft dysfunction (defined as either primary nonfunction or initial poor function, according to the Ploeg-Maring criteria) and Clavien II-IV complications in the first postoperative week. Domino and deceased donor recipients had similar preoperative severity indices (Child-Pugh classification and Model for End-Stage Liver Disease score) and immediate postoperative severity scores (APACHE II [Acute Physiology and Chronic Health Evaluation II] and SAPS II [Simplified Acute Physiology Score II]). In DLT, donors were younger, cold ischemia time was shorter, and intraoperative transfusion requirements of packed red blood cells and fresh-frozen plasma were significantly lower. Graft dysfunction incidence was 3.4-fold lower in DLT: 5.2% (only 4 cases of initial poor function) versus 18.0% (1 primary nonfunction and 15 cases of initial poor function), P = 0.010. Postoperative bleeding was the most frequent early Clavien II-IV complication (n = 29, 17.3%), with an incidence 2.2-fold lower in domino recipients. A statistically significant difference was not found in the other analyzed Clavien II-IV complications, intensive care unit stay, mechanical ventilation time, intensive care unit mortality, and 1-year survival rate. In conclusion, in this study the younger donors and shorter ischemic time associated with DLT may provide a protective role in regards to graft dysfunction and perioperative bleeding, which are 2 important determinants of early morbidity after liver transplantation.

Cardiac tamponade secondary to methicillin-resistant Staphylococcus aureus pericarditis

Since the advent of antibiotics, bacterial pericarditis has become relatively rare. Cardiac tamponade is a potentially lethal complication, especially when caused by methicillin-resistant Staphylococcus aureus (MRSA). In the intensive care setting other predisposing factors for purulent pericarditis, besides immunosuppression, are the high incidence of nasal and skin colonization and invasive techniques such as indwelling catheters. We present two case reports of cardiac tamponade in young patients, with underlying immunosuppression of different etiologies (HIV infection and liver transplantation). In both, clinical evolution was complicated by severe sepsis, with MRSA being isolated in various biological products, followed by bacterial pericarditis and tamponade. The authors highlight the need for a high degree of suspicion for the diagnosis of bacterial pericarditis in immunosuppressed patients, an ever-growing population, as well as the importance of echocardiographic monitoring during clinical evolution.

Prevalence and clinical characterisation of patients with severe partial respiratory failure admitted to an intensive care unit

OBJECTIVE

The authors analysed patients with severe partial respiratory failure (SPRF) admitted to a general Intensive Care Unit (ICU). The prevalence and clinical characteristics of these patients were evaluated. This work aims to study the rate of and to clinically characterise the patient population admitted to an Intensive Care Unit with acute severe partial respiratory failure.

MATERIAL AND METHODS

In 16-bed ICU of a central Hospital in Lisbon, patients admitted in the year 2004 were analysed. Patients with SPRF were recruited form patients with an ICU stay> 24 hours. They were selected according to PaO2 and FiO2 and clinically characterized.

RESULTS

During the study period 472 patients were admitted, and 378 presented an ICU stay> 24 hours and were enrolled. From those, 142 (37.6%) met criteria for SPRF. Of these, 45 (31.7%) a pulmonary aetiology of SPRF was identified. Patients with SRPF were older, had longer ICU stay, and presented higher severity indexes and mortality. The prevalence of adult respiratory distress syndrome was possible to evaluate in the deceased patients with SPRF (n=52). In these we could find 12 (23%) patients that met criteria for that entity. By multivariate analysis the mortality of patients with SRPF correlated with older age and the presence of circulatory failure (p<0.001).

CONCLUSIONS

SPRF is a situation highly prevalent in the ICU studied. To better understand the prevalence of this entity, properly designed studies are needed in order to establish its epidemiology and clinical characteristics.

[Pneumocystis and cytomegalovirus pneumonia in HIV patients - two clinical cases]

Cytomegalovirus is capable of causing disease in immunocompromised patients. In people infected by the Human Immunodeficiency Virus (HIV) it becomes an important agent when there is advanced immunosupression. Its role as a pulmonary pathogen in these patients has been questioned. In the case of pneumocystosis the presence of Cytomegalovirus doesn't seem to worsen prognosis, except in cases where corticosteroids are used. Authors present two cases of patients with HIV infection and advanced immunosupression who were admitted in the intensive care unit for respiratory failure. In both Pneumocystis jirovecii was isolated from.

A ecocardiografia transtorácica na avaliação da hipotensão em cuidados intensivos polivalentes

a prospective study to determine the value of transthoracic echocardiography (TTE) in assessing hypotensive patients in a medical/surgical Intensive care Unit (ICU).a 16-bed medical/surgical ICU.patients with hypotension were studied (systolic arterial pressure < 90 mmHg or mean arterial pressure < 60 mmHg, non responsive to fluid therapy in a 30-minute period). TTE was aimed to: exclude severe cardiac dysfunction(abnormalities requiring immediate therapeutic decision); to evaluate other non severe cardiac alterations; to determine cardiac index (CI) and analyse inferior vena cava (IVC).Two hundred eight patients were studied, and 198 enrolled (4.5% of impossible examinations), with a mean age 63.4 +/- 16.2 years, 129 male, APACHE II score 30.1 +/- 9.9, SAPS II 68.8 +/- 20.5, SOFA 11.6 +/- 3.8, MODS 10.9 +/- 3.9. Mortality was 51% (n=101) and 168 (82.2%) patients were under mechanical ventilation. Forty four patients (44.4%) presented cardiac abnormalities, 28 of whom (14%) severe cardiac diseases. Of these, 18 (9%) presented unsuspected situations (aortic stenosis, 3; endocarditis, 4, dilated miocardiopathy, 9, cardiac tamponade, 2). Patients with cardiac abnormalities were older and presented higher severity scores and mortality. Most patients (158, 79.7%) presented a normal/high IC, all with low peripheral vascular resistance. Through logistic regression analysis, a statistically significant between IVC index and ICU stay (p=0.05); IC and IVC index correlated with overall mortality (p=0,008 and 0,041 respectively).Patients with hypotension in a medical/surgical ICU presented a high rate of cardiac abnormalities (44.4%, n=88), including 26 patients with severe diseases, requiring immediate therapeutic decisions. IC and IVC analysis may be useful to determine hemodynamic profile and several TTE parameters may have prognostic value.

Determinação não invasiva da pressão de encravamento da artéria pulmonar por ecocardiografia

Pulmonary capillary wedge pressure (Pw) is an important hemodynamic parameter frequently used in Intensive Care. Much effort was taken by investigators to noninvasively obtain this parameter particularly using echocardiography. The authors reviewed the published works in this field. There are a great number of correlations between echocardiographic variables and Pw, including equations for its precise assessment. Changes in echocardiographic parameters due to modifications in volume status and more recently tissue Doppler evaluation are also related fields. Despite the quality and quantity of investigation, no single method was established or accepted for non-invasive assessment of Pw using echocardiography. The major problems are related to the study of different populations regarding its basic clinical condition and to the complexity of equations described. Non-invasive assessment of Pw in clinical setting using echocardiography is still a hard task for this technique. Probably, the use of echocardiography as a non-invasive tool for hemodynamic assessment should use other methodologies, and not rely on Pw determination.

Non invasive evaluation of central venous pressure using echocardiography in the intensive care--specific features of patients with right ventricular enlargement and chronic exacerbated pulmonary disease

OBJECTIVES

To determine the possibility of non-invasive estimation of central venous pressure (CVP) through inferior vena cava (IVC) analysis, using transthoracic echocardiography (TTE).

DESIGN

A prospective 3-year study.

SETTING

A 16-bed medical/surgical Intensive Care Unit (ICU).

METHODS

Patients admitted to the ICU were enrolled. CVP measurement and TTE (determining cardiac chambers dimension and left ventricular shortening fraction) with IVC analysis (maximum dimension and IVC index) were performed simultaneously. Parametric and non-parametric statistical analysis was performed to establish correlations between variables.

RESULTS

560 patients were admitted to the study, including 477 in whom IVC was analysed, aging 62.2 +/- 17.3 years, a mean ICU stay 11.9 +/- 18.7 days, a APA- CHE II score 23.9 +/- 8.9 and a SAPS II score 55.7 +/- 20.4. Through linear regression analysis CVP was influenced by IVC index (p=0.001), IVC maximum dimension (p=0.013) and presence of mechanical ventilation (p=0.002). A statistically significant correlation was found between the following parameters: an IVC index < 25% and a CVP > 13 mmHg; an IVC index and a CVP 26%-50%; an IVC index > 51% and CVP < 7 mmHg; an IVC maximum dimension > 20mm and a CVP > 13 mmHg; an IVC maximum dimension < 10 mmHg and CVP < 7 mmHg. Patients with right ventricle enlargement presented a lack of agreement between IVC maximum dimension and CVP > 7 mmHg was observed, and in patients with chronic respiratory failure (who presented a high prevalence of right ventricular enlargement) a lack of agreement between IVC index > 50% and CVP < 7 mmHg was also observed.

CONCLUSIONS

IVC analysis is a possible way to non-invasively estimate CVP in a medical /surgical ICU. However, patients with right ventricular enlargement and admitted with chronic respiratory failure present a lack of agreement between IVC parameters and low values of CVP. IVC dimension is a marker of chronic disease and IVC index correlated better with CVP.

[Transthoracic echocardiography for evaluation of hypotensive critically ill patient]

OBJECTIVES AND DESIGN

a prospective study to determine the value of transthoracic echocardiography (TTE) in assessing hypotensive patients in a medical/surgical Intensive care Unit (ICU).

SETTING

a 16-bed medical/surgical ICU.

MATERIAL AND METHODS

patients with hypotension were studied (systolic arterial pressure < 90 mmHg or mean arterial pressure < 60 mmHg, non responsive to fluid therapy in a 30-minute period). TTE was aimed to: exclude severe cardiac dysfunction(abnormalities requiring immediate therapeutic decision); to evaluate other non severe cardiac alterations; to determine cardiac index (CI) and analyse inferior vena cava (IVC).

RESULTS

Two hundred eight patients were studied, and 198 enrolled (4.5% of impossible examinations), with a mean age 63.4 +/- 16.2 years, 129 male, APACHE II score 30.1 +/- 9.9, SAPS II 68.8 +/- 20.5, SOFA 11.6 +/- 3.8, MODS 10.9 +/- 3.9. Mortality was 51% (n=101) and 168 (82.2%) patients were under mechanical ventilation. Forty four patients (44.4%) presented cardiac abnormalities, 28 of whom (14%) severe cardiac diseases. Of these, 18 (9%) presented unsuspected situations (aortic stenosis, 3; endocarditis, 4, dilated miocardiopathy, 9, cardiac tamponade, 2). Patients with cardiac abnormalities were older and presented higher severity scores and mortality. Most patients (158, 79.7%) presented a normal/high IC, all with low peripheral vascular resistance. Through logistic regression analysis, a statistically significant between IVC index and ICU stay (p=0.05); IC and IVC index correlated with overall mortality (p=0,008 and 0,041 respectively).

CONCLUSIONS

Patients with hypotension in a medical/surgical ICU presented a high rate of cardiac abnormalities (44.4%, n=88), including 26 patients with severe diseases, requiring immediate therapeutic decisions. IC and IVC analysis may be useful to determine hemodynamic profile and several TTE parameters may have prognostic value.

[Non invasive assessment of pulmonary capillary wedge pressure using echocardiography]

Pulmonary capillary wedge pressure (Pw) is an important hemodynamic parameter frequently used in Intensive Care. Much effort was taken by investigators to noninvasively obtain this parameter particularly using echocardiography. The authors reviewed the published works in this field. There are a great number of correlations between echocardiographic variables and Pw, including equations for its precise assessment. Changes in echocardiographic parameters due to modifications in volume status and more recently tissue Doppler evaluation are also related fields. Despite the quality and quantity of investigation, no single method was established or accepted for non-invasive assessment of Pw using echocardiography. The major problems are related to the study of different populations regarding its basic clinical condition and to the complexity of equations described. Non-invasive assessment of Pw in clinical setting using echocardiography is still a hard task for this technique. Probably, the use of echocardiography as a non-invasive tool for hemodynamic assessment should use other methodologies, and not rely on Pw determination.

[Hybrid or continuous renal replacement techniques for unstable haemodynamic patients in the intensive care unit]

OBJECTIVE

Comparative study to evaluate the impact of a hybrid renal replacement technique (HRRT) vs a continuous renal replacement technique (haemodiafiltration) on hemodynamic tolerance, azotemic control, and mortality in critical care patients with acute renal failure.

SETTING

a 14-bed Intensive Care Unit (ICU).

MATERIAL AND METHODS

Two groups of patients were retrospectively compared: patients submitted to continuous renal replacement techniques (CRRT) in 2003 (n = 26) and patients who underwent HRRT in 2004 (n = 27). Both groups had similar severity scores and underlying diseases, and were haemodynamically unstable. Urea and creatinine reduction ratio (URR and CRR) in both groups were evaluated.

RESULTS

Patients treated with HRRT presented a lower mortality (62% vs 84%), less heparin use, and a higher URR and CRR. Univariate logistic regression showed that an increase in APACHE II was related to an increase in mortality (CI 95%, 1.03-1.26). Odds for mortality for CRRT group were about 3 times higher (CI 95%, 0.86-12.11), but not statistically significant (p = 0.074).

CONCLUSION

HRRT is a valid alternative to CRRT in haemodynamically unstable critically ill patients.

Haemodynamic parameters obtained by transthoracic echocardiography and Swan-Ganz catheter: a comparative study in liver transplant patients

OBJECTIVE

To compare the haemodynamic measurements of cardiac output (CO), central venous pressure (CVP), pulmonary capillary wedge pressure (Pw) and pulmonary artery systolic pressure (PASP), obtained by Swan-Ganz catheter and transthoracic echocardiography.

MATERIAL AND METHODS

Prospective study in a Medical/Surgical Intensive Care Unit (ICU). A total of 41 post liver transplant patients were enrolled. CO, CVP, Pw and PASP, were simultaneously determined by two independent observers, utilizing a Swan-Ganz catheter and transthoracic echocardiography, using equations described in the literature. A linear correlation and a Bland-Altman analysis were performed.

RESULTS

A good correlation between invasive and non- invasive measurements for CO (r=0.97) and CVP (r=0.88) was found, but determinations of Pw (r=0.41) and PASP (r=0.18) did not correlate well. Bias and 95% confidence interval for CO were negligible namely when a CO<6 l/min was considered. Pulsed-wave Doppler-echocardiography underestimates the CO when compared with thermodilution, but the 2 techniques agree on average and can be used interchangeably.

CONCLUSIONS

The non-invasive determination of CO in critical care post liver transplant patients correlates well with the invasive determinations. Transthoracic echocardiography was not appropriate for calculating filling parameters studied. Although the data was obtained in post liver transplant patients, they could be useful in defining the role of echocardiography in the ICU.

[Cardiac influence on mechanical ventilation time and mortality in exacerbated chronic respiratory failure patients. The role of echocardiographic parameters]

OBJECTIVE

To study the influence of cardiac status on the length of mechanical ventilation, outcome and disease severity in patients admitted to an Intensive Care Unit (ICU) with exacerbation of chronic respiratory failure.

DESIGN AND SETTING

A 30-month prospective study in a 14 bed ICU PATIENTS AND METHODS: Fifty nine patients were enrolled, with a mean age 74.7 +/- 9.7 years, mean length of ventilator support 10.8 +/- 12.6 days, and mean APACHE II score 23 +/- 8.3. Within the first 24 hours of admittance, cardiac chamber dimensions, inferior vena cava (IVC), and mitral transvalvular Doppler were evaluated using transthoracic echocardiography; the cardiac rhythm was recorded (presence of sinus rhythm or atrial fibrillation). Blood gases were evaluated at discharge.

RESULTS

Greater length of ventilation was observed in patients presenting atrial fibrillation (p=0.027), particularly when a dilated IVC was also present (>20mm, p=0.004). A high level of serum bicarbonate (>35 mEq/l), was also related with longer ventilation (p=0. 04). Twelve patients died. Mortality was related to the presence of a dilated right ventricle (p=0. 03) and a ratio between right and left ventricle> 0. 6 (p=0.04).

CONCLUSION

Patients submitted to mechanical ventilation due to exacerbation of chronic respiratory failure which present atrial fibrillation require a longer ventilation period, particularly if a dilated IVC is also present. Patients with dilated right cardiac chambers are at an increased risk of a fatal outcome.

Linfopenia em doentes submetidos a ventilação mecânica por exacerbação de insuficiência respiratória crónica: estudo prospectivo

OBJECTIVES

Evaluate and characterize lymphopenia in patients admitted to the Intensive Care Unit (ICU) for mechanical ventilation due to aggravated chronic respiratory failure and its probable relation to severity.

MATERIAL AND METHODS

Prospective study over a period of 6 months with another 6 months follow-up after ICU discharge. The study included 24 patients, 22 males, with mean APACHE II of 19,7, three of whom with capacity for outpatient follow-up. Lymphocyte subpopulations were determined on admission and every 7 days after mechanical ventilation. Patients with evidence of infection or previous immunossupression, with the exception of steroids, were excluded from the study.

RESULTS

Lymphopenia was found in 79,2% of patients with depletion of all lymphocyte series, although with greater expression for B lymphocytes CD19+. This depletion showed no relation with serum steroid levels, and although related to greater clinical severity, no correlation was found with mortality. Lymphocyte values recovered progressively during admission.

CONCLUSIONS

Lymphopenia is frequent among ventilated patients with chronic respiratory exacerbation. It's a non-selective depletion, more evident with CD19+ B lymphocytes. These patients present higher severity scores but no difference in mortality. Outpatient follow-up was difficult and inconclusive.

Case report: purple urine bag syndrome

Purple urine bag syndrome (PUBS) was first reported in 1978. PUBS is rare, occurs predominantly in constipated women, chronically catheterized and associated with some bacterial urinary infections that produce sulphatase/phosphatase. The etiology is due to indigo (blue) and indirubin (red) or to their mixture that becomes purple. A chain reaction begins in the gastrointestinal tract with tryptophan as described in the article.

Cardiac Doppler variation with volume status changes in general intensive care

The authors studied the effect of volume status modification on cardiac Doppler features, with negative fluid balance and corresponding central venous pressure change. This was carried out in 64 patients admitted to the Intensive Care Unit, 24 of whom were under mechanical ventilation. With volume status change, the mitral E/A ratio showed a tendency to decrease, mitral E wave deceleration time decreased, isovolumic relaxation time increased, and the expiratory diameter of the inferior vena cava reduced and its inspiratory collapse increased. No significant correlation was observed between the parameters studied and volume changes, or between central venous pressure and fluid balance. Volume changes in critical care patients modify certain features of Doppler echocardiography, but the magnitude of such variations is unpredictable.

Pulmonary artery catheter--what role in the 21st century?

The pulmonary artery catheter is a diagnostic tool used routinely in cardiological and general intensive care. Since its implementation in the 1970s, serious doubts have been raised concerning its use and efficacy. These problems are a legacy of the 20th century, and may not be solved in this century, but they cannot be ignored. The authors present an overview of this subject, recording in chronological order the principal events and publications concerning the pulmonary artery catheter, highlighting some controversies, most of them unresolved.

The influence of cardiac diastole on weaning from mechanical ventilation

Hemodynamic changes occur during weaning from mechanical ventilation, especially after disconnection from positive pressure ventilation. Their importance has been insufficiently studied, although some refer to their role in weaning. The authors studied the hemodynamic implications after ventilator disconnection, using echocardiography. They found isovolumetric relaxation time to be a good predictor of successful weaning, proving the importance of the diastole changes with the hemodynamic adaptation in the transition to negative pressure ventilation.