Renal dysfunction associated with intra-abdominal hypertension and the abdominal compartment syndrome

[Abdominal compartment syndrome in visceral surgery and intensive care medicine : Causes, prevention, detection, treatment]

An increased intra-abdominal pressure can result in a manifest abdominal compartment syndrome (ACS) with significant organ damage, which is a life-threatening situation associated with a high mortality. Although the etiology is manifold and critically ill patients on the intensive care unit are particularly endangered, the disease is often not diagnosed even though the measurement of bladder pressure is available as a simple and standardized method; however, particularly the early detection of an increased intra-abdominal pressure is decisive in order to prevent the occurrence of a manifest ACS with (multi)organ failure by means of conservative measures. In cases of a conservative refractory situation, decompressive laparotomy is indicated.

Abdominal compartment syndrome: what radiologist needs to know

The intra-abdominal hypertension (IAH) and the abdominal compartment syndrome (ACS) are life-threatening conditions with a significant rate of mortality; therefore, early detection is paramount in their optimal management. IAH is diagnosed when the intra-abdominal pressure (IAP) is more than 12 mmHg. It can occur when the intra-abdominal volume increases (ileus, ascites, trauma, pancreatitis, etc.) and/or the abdominal wall compliance decreases. IAH can cause decreased venous flow, low cardiac output, renal impairment, and decreased respiratory compliance. Consequently, these complications can lead to multiple organ failure and induce the abdominal compartment syndrome (ACS) when IAP rises above 20 mmHg. The diagnosis is usually made with intravesical pressure measurement. However, this measurement was not always possible to obtain; therefore, alternative diagnostic techniques should be considered. In this setting, computed tomography (CT) may play a crucial role, allowing the detection and characterization of pathological conditions that may lead to IAH. This review is focused on the pathogenesis, clinical features, and radiological findings of ACS, because their presence allows radiologists to raise the suspicion of IAH/ACS in critically ill patients, guiding the most appropriate treatment.

Abdominal compartment syndrome in critically ill patients

Intra-abdominal hypertension can have severe consequences, including abdominal compartment syndrome, which can contribute to multi-organ failure. An increase in intra-abdominal hypertension is influenced by factors such as diminished abdominal wall compliance, increased intraluminal content, and certain systemic conditions. Regular measurement of intra-abdominal pressure is essential, and particular attention must be paid to patient positioning. Nonsurgical treatments, such as decompression of intraluminal content using a nasogastric tube, percutaneous drainage, and fluid balance optimization, play crucial roles. Additionally, point-of-care ultrasonography aids in the diagnosis and treatment of intra-abdominal hypertension. Emphasizing the importance of regular measurements, timely decompressive laparotomy is a definitive, but complex, treatment option. Balancing the urgency of surgical intervention against potential postoperative complications is challenging.

The Association Between Intra-abdominal Pressure and Diuretic Response in Heart Failure

PURPOSE OF THE REVIEW

An efficient diuretic response is vital during cardiac decompensation in heart failure (HF) patients. The increase in intra-abdominal pressure (IAP) could be one of the keys for understanding cardiorenal syndrome and guiding diuretic treatment during hospitalization. In this review, we analyze the relationship between IAP and diuretic response in HF patients.

RECENT FINDINGS

Increased IAP is associated with worsening renal function (WRF) in patients with advanced HF. Furthermore, the persistence of a rise in IAP after the first 72 h of intravenous diuretic treatment has been correlated with a worse diuretic response, a higher degree of congestion, and an impaired prognosis. The rise in IAP in HF patients has been associated with impaired renal function and a lower diuretic response. Nonetheless, more studies are needed to elucidate the actual role of IAP in congestive nephropathy and whether it may help guide diuretic therapy during acute decompensations.

Development of a predictive nomogram for acute respiratory distress syndrome in patients with acute pancreatitis complicated with acute kidney injury

BACKGROUND

Acute respiratory distress syndrome (ARDS) is a common complication in patients with acute pancreatitis (AP), especially when patients complicated with acute kidney injury (AKI), resulting in increased duration of hospitalization and mortality. It is of potential clinical significance to develop a predictive model to identify the the high-risk patients.

METHOD

AP patients complicated with AKI from January 2019 to March 2022 were enrolled in this study and randomly divided into training cohort and validation cohort at a ratio of 2:1. The Least absolute shrinkage and selection operator(LASSO) regression and machine learning algorithms were applied to select features. A nomogram was developed based on the multivariate logistic regression. The performance of the nomogram was evaluated by AUC, calibration curves, and decision curve analysis.

RESULTS

A total of 292 patients were enrolled in the study, with 206 in the training cohort and 86 in the validation cohort. Multivariate logistic analysis showed that IAP (Odds Ratio (OR)=4.60, 95%CI:1.23-18.24, p = 0.02), shock (OR = 12.99, 95%CI:3.47-64.04, p < 0.001), CRP(OR= 26.19, 95%CI:9.37-85.57, p < 0.001), LDH (OR = 13.13, 95%CI:4.76-40.42, p < 0.001) were independent predictors of ARDS. The nomogram was developed based on IAP, shock, CRP and LDH. The nomogram showed good discriminative ability with an AUC value of 0.954 and 0.995 in the training and validation cohort, respectively. The calibration curve indicating good concordance between the predicted and observed values. The DCA showed favorable net clinical benefit.

CONCLUSION

This study developed a simple model for predicting ARDS in AP patients complicated with AKI. The nomogram can help clinicians identify high-risk patients and optimize therapeutic strategies.

Pathophysiology of Hepatorenal Syndrome - Acute Kidney Injury

Hepatorenal syndrome is a complication of liver cirrhosis with ascites that results from the complex interplay of many pathogenetic mechanisms. Advanced cirrhosis is characterized by the development of hemodynamic changes of splanchnic and systemic arterial vasodilatation, with paradoxical renal vasoconstriction and renal hypoperfusion. Cirrhosis is also an inflammatory state. The inflammatory cascade is initiated by a portal hypertension-induced increased translocation of bacteria, bacterial products, and endotoxins from the gut to the splanchnic and then to the systemic circulation. The inflammation, whether sterile or related to infection, is responsible for renal microcirculatory dysfunction, microthrombi formation, renal tubular oxidative stress, and tubular damage. Of course, many of the bacterial products also have vasodilatory properties, potentially exaggerating the state of vasodilatation and worsening the hemodynamic instability in these patients. The presence of cardiac dysfunction, related to cirrhotic cardiomyopathy, with its associated systolic incompetence, can aggravate the mismatch between the circulatory capacitance and the circulation volume, worsening the extent of the effective arterial underfilling, with lower renal perfusion pressure, contributing to renal hypoperfusion and increasing the risk for development of acute kidney injury. The presence of tense ascites can exert an intra-abdominal compartmental syndrome effect on the renal circulation, causing renal congestion and hampering glomerular filtration. Other contributing factors to renal dysfunction include the tubular damaging effects of cholestasis and adrenal dysfunction. Future developments include the use of metabolomics to identify metabolic pathways that can lead to the development of renal dysfunction, with the potential of identifying biomarkers for early diagnosis of renal dysfunction and the development of treatment strategies.

Sánchez-Margallo F, Eugenia Candanosa-Aranda I, Poelaert J, Castellanos G, L. N. G. Malbrain M. The pathophysiological impact of intra-abdominal hypertension in pigs

BACKGROUND

Intra-abdominal hypertension and abdominal compartment syndrome are common with clinically significant consequences. We investigated the pathophysiological effects of raised IAP as part of a more extensive exploratory animal study. The study design included both pneumoperitoneum and mechanical intestinal obstruction models.

METHODS

Forty-nine female swine were divided into six groups: a control group (Cr; n = 5), three pneumoperitoneum groups with IAPs of 20mmHg (Pn20; n = 10), 30mmHg (Pn30; n = 10), 40mmHg (Pn40; n = 10), and two mechanical intestinal occlusion groups with IAPs of 20mmHg (MIO20; n = 9) and 30mmHg (MIO30; n = 5).

RESULTS

There were significant changes (p<0.05) noted in all organ systems, most notably systolic blood pressure (SBP) (p<0.001), cardiac index (CI) (p = 0.003), stroke volume index (SVI) (p<0.001), mean pulmonary airway pressure (MPP) (p<0.001), compliance (p<0.001), pO2 (p = 0.003), bicarbonate (p = 0.041), hemoglobin (p = 0.012), lipase (p = 0.041), total bilirubin (p = 0.041), gastric pH (p<0.001), calculated glomerular filtration rate (GFR) (p<0.001), and urine output (p<0.001). SVV increased progressively as the IAP increased with no obvious changes in intravascular volume status. There were no significant differences between the models regarding their impact on cardiovascular, respiratory, renal and gastrointestinal systems. However, significant differences were noted between the two models at 30mmHg, with MIO30 showing worse metabolic and hematological parameters, and Pn30 and Pn40 showing a more rapid rise in creatinine.

CONCLUSIONS

This study identified and quantified the impact of intra-abdominal hypertension at different pressures on several organ systems and highlighted the significance of even short-lived elevations. Two models of intra-abdominal pressure were used, with a mechanical obstruction model showing more rapid changes in metabolic and haematological changes. These may represent different underlying cellular and vascular pathophysiological processes, but this remains unclear.

Intra-abdominal hypertension and abdominal compartment syndrome in acute pancreatitis

Intra-abdominal hypertension (IAH) and abdominal compartment syndrome (ACS) are underrecognized entities in patients of acute pancreatitis (AP). IAH develops in 30% to 60% and ACS in 15% to 30% of all AP patients and they are markers of severe disease with high morbidity and mortality. The detrimental effect of increased IAP has been recognized in several organ systems, including the central nervous system, cardiovascular, respiratory, renal and gastrointestinal systems. The pathophysiology of IAH/ACS development in patients with AP is multifactorial. Pathogenetic mechanisms include over-zealous fluid management, visceral edema, ileus, peripancreatic fluid collections, ascites and retroperitoneal edema. Laboratory and imaging markers are neither sensitive nor specific enough to detect IAH/ACS and intra-abdominal pressure (IAP) monitoring is vital for early diagnosis and the management of patients of AP with IAH/ACS. The treatment of IAH/ACS requires a multi-modality approach with both medical and surgical attention. Medical management consists of nasogastric/rectal decompression, prokinetics, fluid management and diuretics or hemodialysis. If conservative management is not effective, percutaneous drainage of fluid collection or ascites is necessary. Despite medical management, if IAP worsens, surgical decompression is warranted. The review discusses the relevance of IAH/ACS in patients of AP and its management.

Severe Acute Pancreatitis Treated with Negative Pressure Wound Therapy System: Influence of Laboratory Markers

(1) Background: An open abdomen is a serious medical condition that requires prompt and effective treatment to prevent complications and improve patient outcomes. Negative pressure therapy (NPT) has emerged as a viable therapeutic option for temporary closure of the abdomen, offering several benefits over traditional methods. (2) Methods: We included 15 patients with pancreatitis who were hospitalized in the I-II Surgery Clinic of the Emergency County Hospital "St. Spiridon" from Iasi, Romania, between 2011-2018 and received NPT. (3) Results: Preoperatively, the mean IAP level was 28.62 mmHg, decreasing significantly postoperatively to 21.31 mmHg. The mean level of the highest IAP value recorded in pancreatitis patients treated with VAC did not differ significantly by lethality (30.31 vs. 28.50; p = 0.810). In vacuum-treated pancreatitis patients with a IAP level > 12, the probability of survival dropped below 50% during the first 7 days of stay in the ICU, so that after 20 days the probability of survival was approximately 20%. IAP enters the determinism of surgery with a sensitivity of 92.3% and a specificity of 99%, the cut-off value of IAP being 15 mmHg. (4) Conclusions: The timing of surgical decompression in abdominal compartment syndrome is very important. Consequently, it is vital to identify a parameter, easy to measure, within the reach of any clinician, so that the indication for surgical intervention can be made judiciously and without delay.

Intra-abdominal hypertension in cardiac surgery patients: a multicenter observational sub-study of the Accuryn registry

Intra-abdominal hypertension (IAH) is frequently present in the critically ill and is associated with increased morbidity and mortality. Conventionally, intermittent 'spot-check' manual measurements of bladder pressure in those perceived as high risk are used as surrogates for intra-abdominal pressure (IAP). True patterns of IAH remain unknown. We explored the incidence of IAH in cardiac surgery patients and describe the intra-and postoperative course of IAP using a novel, high frequency, automated bladder pressure measurement system. Sub-analysis of a prospective, multicenter, observational study (NCT04669548) conducted in three large academic medical centers. Continuous urinary output (CUO) and IAP measurements were observed using the Accuryn Monitoring System (Potrero Medical, Hayward, CA). Data collected included demographics, hemodynamic support, and high-frequency IAP and CUO. One Hundred Thirty-Seven cardiac surgery patients were analyzed intraoperatively and followed 48 h postoperatively in the intensive care unit. Median age was 66.4 [58.3, 72.0] years, and 61% were men. Median Foley catheter dwell time was 56.0 [46.8, 77.5] hours, and median baseline IAP was 6.3 [4.0, 8.1] mmHg. 93% (128/137) of patients were in IAH grade I, 82% (113/137) in grade II, 39% (53/137) in grade III, and 5% (7/137) in grade IV for at least 12 cumulative hours. For maximum consecutive duration of IAH, 84% (115/137) of patients spent at least 12 h in grade I, 62% (85/137) in grade II, 18% (25/137) in grade III, and 2% (3/137) in grade IV IAH. During the first 48 h after cardiac surgery, IAH is common and persistent. Improved and automated monitoring of IAP will increase the detection of IAH-which normally would remain undetected using traditional intermittent monitoring methods.

Effect of Aggressive Intravenous Fluid Resuscitation Versus Nonaggressive Fluid Resuscitation in the Treatment of Acute Pancreatitis: A Systematic Review and Meta-Analysis

OBJECTIVES

Despite the need for active fluid therapy, fluid management of most acute pancreatitis (AP) cases is still supportive. The aim of this review is to compare the effect of aggressive versus nonaggressive intravenous (IV) fluid resuscitation in the treatment of acute pancreatitis.

METHODS

A systematic search of medical databases, such as Medline, Google Scholar, Science Direct, Cochrane Central, was conducted for publication until April 2022. We included randomized controlled trials or cohort (prospective and retrospective) studies reporting the outcomes of AP in patients that were managed with aggressive and nonaggressive IV fluid resuscitation. The primary outcome of interest was in-hospital mortality.

RESULTS

Fourteen trials involving 3423 acute pancreatitis patients were included in the review. We did not observe any differences in the risk of mortality, persistent organ failure, and systemic inflammatory response syndrome in both study groups. However, there was an increased risk of development of pancreatic necrosis, renal failure, and respiratory failure in the aggressive fluid therapy group compared with nonaggressive therapy. The funnel plot showed no publication bias.

CONCLUSIONS

Aggressive fluid therapy did not improve mortality rates in acute AP patients and was associated with an increased risk of acute renal failure, and respiratory failure.

Selection of appropriate reference creatinine estimate for acute kidney injury diagnosis in patients with severe trauma

BACKGROUND

In patients with severe trauma, the diagnosis of acute kidney injury (AKI) is important because it is a predictive factor for poor prognosis and can affect patient care. The diagnosis and staging of AKI are based on change in serum creatinine (SCr) levels from baseline. However, baseline creatinine levels in patients with traumatic injuries are often unknown, making the diagnosis of AKI in trauma patients difficult. This study aimed to enhance the accuracy of AKI diagnosis in trauma patients by presenting an appropriate reference creatinine estimate (RCE).

METHODS

We reviewed adult patients with severe trauma requiring intensive care unit admission between 2015 and 2019 (n=3,228) at a single regional trauma center in South Korea. AKI was diagnosed based on the current guideline published by the Kidney Disease: Improving Global Outcomes organization. AKI was determined using the following RCEs: estimated SCr75-modification of diet in renal disease (MDRD), trauma MDRD (TMDRD), admission creatinine level, and first-day creatinine nadir. We assessed inclusivity, prognostic ability, and incrementality using the different RCEs.

RESULTS

The incidence of AKI varied from 15% to 46% according to the RCE used. The receiver operating characteristic curve of TMDRD used to predict mortality and the need for renal replacement therapy (RRT) had the highest value and was statistically significant (0.797, P<0.001; 0.890, P=0.002, respectively). In addition, the use of TMDRD resulted in a mortality prognostic ability and the need for RRT was incremental with AKI stage.

CONCLUSIONS

In this study, TMDRD was feasible as a RCE, resulting in optimal post-traumatic AKI diagnosis and prognosis.

Abdominal Compartment Syndrome in Acute Pancreatitis: A Narrative Review

Abdominal compartment syndrome (ACS) represents a severe complication of acute pancreatitis (AP), resulting from an acute and sustained increase in abdominal pressure >20 mmHg, in association with new organ dysfunction. The harmful effect of high intra-abdominal pressure on regional and global perfusion results in significant multiple organ failure and is associated with increased morbidity and mortality. There are several deleterious consequences of elevated intra-abdominal pressure on end-organ function, including respiratory, cardiovascular, gastrointestinal, neurologic, and renal effects. It is estimated that about 15% of patients with severe AP develop intra-abdominal hypertension or ACS, with a mortality rate around 50%. The treatment of abdominal compartment syndrome in acute pancreatitis begins with medical intervention and percutaneous drainage, where possible. Abdominal compartment syndrome unresponsive to conservatory treatment requires immediate surgical decompression, along with vacuum-assisted closure therapy techniques, followed by early abdominal fascia closure.

Spontaneous peritoneal drainage following paracentesis in a hospitalized patient with resolution of type 1 hepatorenal syndrome

The hepatorenal syndrome develops in a small percentage of patients with advanced liver disease. The pathogenesis involves intravascular volume contraction secondary to pooling of blood in the splanchnic vessels, stimulation of the sympathetic nervous system and the renin-angiotensin-aldosterone pathway, and increased intra-abdominal pressure secondary to the formation of large volumes of ascitic fluid. The treatment options are limited, and liver transplant is the only definitive form of management. Here we suggest an alternative approach to treating hepatorenal syndrome based on the unexpected continuous peritoneal drainage in a 36-year-old man hospitalized with hepatic encephalopathy and hepatorenal syndrome. A total of 11.2 L ascitic fluid drained over 5 days from a paracentesis puncture site with marked improvement in renal function; the creatinine decreased from 3.3 mg/dL to 0.7 mg/dL and the BUN decreased from 42 mg/dL to 10 mg/dL. The discussion with this case report summarizes the pathogenesis, including the effect of intra-abdominal pressure, of the hepatorenal syndrome, outlines medical management, and makes a proposal for clinical study based on this case.

Risk factors for abdominal compartment syndrome in trauma – A review

" Background and Aim: Abdominal compartment syndrome is a life-threatening complication that can occur in trauma patients and greatly increase their mortality. Although there is a better scientific understanding of the general phenomena involved in the pathogenesis of this complication, the particular risk factors and their implications in the trauma patient population are yet to be deciphered. Methods: The authors conducted research through 3 electronic databases (PubMed, Scopus, and ScienceDirect) using the following search formula: “(ACS OR abdominal compartment syndrome) AND (*trauma*) AND (risk factor)”. Subsequently, additional search formulas were used, including the risk factors taken into consideration (i.e. “shock”, “hypotension”, “acidosis”, “base deficit”, ”coagulopathy”, “retroperitoneal hematoma”, “HOB elevation”, “fluid resuscitation”, “damage control laparotomy”). Results: Throughout the 41 articles analyzed in this paper, 7 risk factors transcended and were further discussed: head of bed elevation/patient positioning, fluid resuscitation, the “lethal triad” of acidosis hypothermia and coagulopathy, Damage Control Laparotomy, shock/hypotension, retroperitoneal hematoma and demographics (age, gender, and race). Conclusions: To summarize, many potential risk factors were evaluated for the envisagement of the present paper, but the ones that prevailed the most were excessive fluid resuscitation, shock/hypotension, retroperitoneal hematomas, and the lethal triad. Consistent with other studies, no connection was found between age, gender, or race and the development of ACS. Further studies should focus more on the likely involvement of damage control laparotomy and patient positioning, as well as hypocalcemia, in the unfolding of ACS in trauma patients"

COVID-19 and hepatorenal syndrome

Coronavirus disease 2019 (COVID-19) is a highly infectious disease which emerged into a global pandemic. Although it primarily causes respiratory symptoms for affected patients, COVID-19 was shown to have multi-organ manifestations. Elevated liver enzymes appear to be commonly observed during the course of COVID-19, and there have been numerous reports of liver injury secondary to COVID-19 infection. It has been established that patients with pre-existing chronic liver disease (CLD) are more likely to have poorer outcomes following COVID-19 infection compared to those without CLD. Co-morbidities such as diabetes, hypertension, obesity, cardiovascular and chronic kidney disease frequently co-exist in individuals living with CLD, and a substantial population may also live with some degree of frailty. The mechanisms of how COVID-19 induces liver injury have been postulated. Hepatorenal syndrome (HRS) is the occurrence of kidney dysfunction in patients with severe CLD/fulminant liver failure in the absence of another identifiable cause, and is usually a marker of severe decompensated liver disease. Select reports of HRS following acute COVID-19 infection have been presented, although the risk factors and pathophysiological mechanisms leading to HRS in COVID-19 infection or following COVID-19 treatment remain largely unestablished due to the relative lack and novelty of published data. Evidence discussing the management of HRS in high-dependency care and intensive care contexts is only emerging. In this article, we provide an overview on the speculative pathophysiological mechanisms of COVID-19 induced HRS and propose strategies for clinical diagnosis and management to optimize outcomes in this scenario.

Edema formation in congestive heart failure and the underlying mechanisms

Congestive heart failure (HF) is a complex disease state characterized by impaired ventricular function and insufficient peripheral blood supply. The resultant reduced blood flow characterizing HF promotes activation of neurohormonal systems which leads to fluid retention, often exhibited as pulmonary congestion, peripheral edema, dyspnea, and fatigue. Despite intensive research, the exact mechanisms underlying edema formation in HF are poorly characterized. However, the unique relationship between the heart and the kidneys plays a central role in this phenomenon. Specifically, the interplay between the heart and the kidneys in HF involves multiple interdependent mechanisms, including hemodynamic alterations resulting in insufficient peripheral and renal perfusion which can lead to renal tubule hypoxia. Furthermore, HF is characterized by activation of neurohormonal factors including renin-angiotensin-aldosterone system (RAAS), sympathetic nervous system (SNS), endothelin-1 (ET-1), and anti-diuretic hormone (ADH) due to reduced cardiac output (CO) and renal perfusion. Persistent activation of these systems results in deleterious effects on both the kidneys and the heart, including sodium and water retention, vasoconstriction, increased central venous pressure (CVP), which is associated with renal venous hypertension/congestion along with increased intra-abdominal pressure (IAP). The latter was shown to reduce renal blood flow (RBF), leading to a decline in the glomerular filtration rate (GFR). Besides the activation of the above-mentioned vasoconstrictor/anti-natriuretic neurohormonal systems, HF is associated with exceptionally elevated levels of atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP). However, the supremacy of the deleterious neurohormonal systems over the beneficial natriuretic peptides (NP) in HF is evident by persistent sodium and water retention and cardiac remodeling. Many mechanisms have been suggested to explain this phenomenon which seems to be multifactorial and play a major role in the development of renal hyporesponsiveness to NPs and cardiac remodeling. This review focuses on the mechanisms underlying the development of edema in HF with reduced ejection fraction and refers to the therapeutic maneuvers applied today to overcome abnormal salt/water balance characterizing HF.

Case Report: Tachycardia, Hypoxemia and Shock in a Severely Burned Pediatric Patient

Background

Severely burned children are at high risk of secondary intraabdominal hypertension and abdominal compartment syndrome (ACS). ACS is a life-threatening condition with high mortality and requires an effective, minimally invasive treatment to improve the prognosis when the condition is refractory to conventional therapy.

Case presentation

A 4.5-year-old girl was admitted to our hospital 30 h after a severe burn injury. Her symptoms of burn shock were relieved after fluid resuscitation. However, her bloating was aggravated, and ACS developed on Day 5, manifesting as tachycardia, hypoxemia, shock, and oliguria. Invasive mechanical ventilation, vasopressors, and percutaneous catheter drainage were applied in addition to medical treatments (such as gastrointestinal decompression, diuresis, sedation, and neuromuscular blockade). These treatments did not improve the patient's condition until she received continuous renal replacement therapy. Subsequently, her vital signs and laboratory data improved, which were accompanied by decreased intra-abdominal pressure, and she was discharged after nutrition support, antibiotic therapy, and skin grafting.

Conclusion

ACS can occur in severely burned children, leading to rapid deterioration of cardiopulmonary function. Patients who fail to respond to conventional medical management should be considered for continuous renal replacement therapy.

Chryseobacterium Indologenes Sepsis and Acute Renal Failure Secondary to Abdominal Compartment Syndrome in a Confirmed COVID-19 Patient

Sepsis due to nosocomial pathogens markedly increases morbidity and mortality in the critically ill patient. The SARS-CoV-2 (COVID-19) pandemic has increased the number of patients requiring intensive care unit (ICU) in-patient management. Chryseobacterium indologenes (C. indologenes) is a group of multiresistant gram-negative bacteria associated with in-hospital environment and catheter-associated infections of increasing importance in the ICU. SARS-CoV-2 severe infection in the critically ill patient increases the risk of abdominal compartment syndrome (ACS) and acute kidney injury (AKI). We hereby report a case of a patient with SARS-CoV-2 severe infection, C. indologenes sepsis, abdominal compartment syndrome, and secondary renal failure.

Abdominal compartment syndrome: an often overlooked cause of acute kidney injury

Abdominal compartment syndrome (ACS) is defined as any organ dysfunction caused by intra-abdominal hypertension (IAH), referred as intra-abdominal pressure (IAP) ≥ 12 mm Hg according to the World Society of Abdominal Compartment Syndrome. Abdominal compartment syndrome develops in most cases when IAP rises above 20 mmHg. Abdominal compartment syndrome, while being a treatable and even preventable condition if detected early in the stage of intra-abdominal hypertension, is associated with high rates of morbidity and mortality if diagnosis is delayed: therefore, early detection is essential. Acute kidney injury (AKI) is a common comorbidity, affecting approximately one in every five hospitalized patients, with a higher incidence in surgical patients. AKI in response to intra-abdominal hypertension develops as a result of a decline in cardiac output and compression of the renal vasculature and renal parenchyma. In spite of the high incidence of intra-abdominal hypertension, especially in surgical patients, its potential role in the pathophysiology of AKI has been investigated in very few clinical studies and is commonly overlooked in clinical practice despite being potentially treatable and reversible. Aim of the present review is to illustrate the current evidence on the pathophysiology, diagnosis and therapy of intra-abdominal hypertension and abdominal compartment syndrome in the context of AKI.

Impact of intra-abdominal pressure on early kidney transplant outcomes

Increased intra-abdominal pressure (IAP) is common among post-surgical patients and may cause organ dysfunction. However, its impact after kidney transplantation on early postoperative complications and graft recovery remains unclear. We designed a prospective, observational cohort study to describe the prevalence and determinants of IAP, as well as its effect on delayed graft function, postoperative complications, and graft recovery. IAP was measured in 205 kidney transplant recipients every 8 h during the first 72 h after surgery using the urinary bladder technique. Intra-abdominal hypertension was defined as IAP ≥ 12 mmHg. Patients were followed for 6 months or until graft failure/death. Mean IAP was 12 ± 3.3 mmHg within the first 24 h. 78% of subjects presented with intra-abdominal hypertension during the first 72 h. Increased IAP was associated with higher renal resistive index [r = 0.213; P = 0.003] and lower urine output [r =  - 0.237; P < 0.001]. 72 h mean IAP was an independent risk factor for delayed graft function [OR: 1.31; 95% CI: 1.13-1.51], postoperative complications [OR: 1.17; 95% CI: 1.03-1.33], and absence of graft function recovery [HR for graft function recovery: 0.94; 95% CI: 0.88-0.99]. Increased IAP was highly prevalent after transplantation and was independently associated with delayed graft function, postoperative complications, and absence of graft function recovery. Routine IAP monitoring should be considered post-transplantation to facilitate early recognition of relevant complications.

Urinary catheter monitoring of intra-abdominal pressure after major abdominal surgery, a cost-benefit analysis

OBJECTIVE

To estimate costs and benefits associated with measurement of intra-abdominal pressure (IAP).

METHODS

We built a cost-benefit analysis from the hospital facility perspective and time horizon limited to hospitalization for patients undergoing major abdominal surgery for the intervention of urinary catheter monitoring of IAP. We used real-world data estimating the likelihood of intra-abdominal hypertension (IAH), abdominal compartment syndrome (ACS), and acute kidney injury (AKI) requiring renal replacement therapy (RRT). Costs included catheter costs (estimated $200), costs of additional intensive care unit (ICU) days from IAH and ACS, and costs of CRRT. We took the preventability of IAH/ACS given early detection from a trial of non-surgical interventions in IAH. We evaluated uncertainty through probabilistic sensitivity analysis and the effect of individual model parameters on the primary outcome of cost savings through one-way sensitivity analysis.

RESULTS

In the base case, urinary catheter monitoring of IAP in the perioperative period of major abdominal surgery had 81% fewer cases of IAH of any grade, 64% fewer cases of AKI, and 96% fewer cases of ACS. Patients had 1.5 fewer ICU days attributable to IAH (intervention 1.6 days vs. control of 3.1 days) and a total average cost reduction of $10,468 (intervention $10,809, controls $21,277). In Monte Carlo simulation, 86% of 1,000 replications were cost-saving, for a mean cost savings of $10,349 (95% UCI $8,978, $11,720) attributable to real-time urinary catheter monitoring of intra-abdominal pressure. One-way factor analysis showed the pre-test probability of IAH had the largest effect on cost savings and the intervention was cost-neutral at a prevention rate as low as 2%.

CONCLUSIONS

In a cost-benefit model using real-world data, the potential average in-hospital cost savings for urinary catheter monitoring of IAP for early detection and prevention of IAH, ACS, and AKI far exceed the cost of the catheter.

Intra-abdominal pressure during and after cardiac surgery: a single-centre prospective cohort study

PURPOSE

While intra-abdominal hypertension (IAH) has been associated with adverse outcomes in multiple settings, the epidemiology and clinical implications of IAH in the context of cardiac surgery are less known. In this study, we aimed to describe the prevalence of IAH in patients undergoing cardiac surgery and determine its association with patient characteristics and postoperative outcomes.

METHODS

We conducted a single-centre prospective cohort study in which intra-abdominal pressure was measured in the operating room after general anesthesia (T1), after the surgical procedure (T2), and two hours after intensive care unit (ICU) admission (T3) in a subset of patients. Intra-abdominal hypertension was defined as intra-abdominal pressure (IAP) ≥ 12 mm Hg. Postoperative outcomes included death, acute kidney injury (AKI), and length of stay in the ICU and hospital.

RESULTS

A total of 513 IAP measurements were obtained from 191 participants in the operating room and 131 participants in the ICU. Intra-abdominal hypertension was present in 105/191 (55%) at T1, 115/191 (60%) at T2, and 31/131 (24%) at T3. Intra-abdominal pressure was independently associated with body mass index, central venous pressure, and mean pulmonary artery pressure but was not associated with cumulative fluid balance. Intraoperative IAH was not associated with adverse outcomes including AKI.

CONCLUSIONS

Intra-abdominal hypertension is very common during cardiac surgery but its clinical implications are uncertain.

Point of care venous Doppler ultrasound: Exploring the missing piece of bedside hemodynamic assessment

Accurate assessment of the hemodynamic status is vital for appropriate management of patients with critical illness. As such, there has been a constant quest for reliable and non-invasive bedside tools to assess and monitor circulatory status in order to ensure end-organ perfusion. In the recent past, point of care ultrasonography (POCUS) has emerged as a valuable adjunct to physical examination in various specialties, which basically is a clinician-performed bedside ultrasound to answer focused questions. POCUS allows visualization of the internal anatomy and flow dynamics in real time, guiding apt interventions. While both arterial (forward flow) and venous (organ outflow or afterload) limbs of hemodynamic circuit are important for tissue perfusion, the venous side remains relatively under-explored. With recent data underscoring the deleterious consequences of iatrogenic volume overload, objective evaluation of venous congestion is gaining attention. Bedside Doppler ultrasound serves this purpose and aids in diagnosing and monitoring the congestion/venous blood flow pattern. In this article, we summarize the rationale for integrating this technology into routine care of patients with volume-related disorders, discuss the normal and abnormal waveforms, limitations, and future directions.

Intra-abdominal hypertension and abdominal compartment syndrome in critically ill patients: A narrative review of past, present, and future steps

BACKGROUND AND OBJECTIVE

Intra-abdominal hypertension is frequently present in critically ill patients and is an independent predictor for mortality. In this narrative review, we aim to provide a comprehensive overview of current insights into intra-abdominal pressure monitoring, intra-abdominal hypertension, and abdominal compartment syndrome. The focus of this review is on the pathophysiology, risk factors and outcome of intra-abdominal hypertension and abdominal compartment syndrome, and on therapeutic strategies, such as non-operative management, surgical decompression, and management of the open abdomen. Finally, future steps are discussed, including propositions of what a future guideline should focus on.

CONCLUSIONS

Pathological intra-abdominal pressure is a continuum ranging from mild intra-abdominal pressure elevation without clinically significant adverse effects to substantial increase in intra-abdominal pressure with serious consequences to all organ systems. Intra-abdominal pressure monitoring should be performed in all patients at risk of intra-abdominal hypertension. Although continuous intra-abdominal pressure monitoring is feasible, this is currently not standard practice. There are a number of effective non-operative medical interventions that may be performed early in the patient's course to reduce intra-abdominal pressure and decrease the need for surgical decompression. Abdominal decompression can be life-saving when abdominal compartment syndrome is refractory to non-operative treatment and should be performed expeditiously. The objectives of open abdomen management are to prevent fistula and to achieve delayed fascial closure at the earliest possible time. There is still a lot to learn and change. The 2013 World Society of Abdominal Compartment Syndrome guidelines should be updated and multicentre studies should evaluate the effect of intra-abdominal hypertension treatment on patient outcome.

Surgery in the Obese Pregnant Patient

This chapter reviews issues which complicate surgery in obese pregnant patients. Maternal obesity is prevalent in the United States and is associated with numerous adverse health outcomes. When surgery is indicated during pregnancy, the presence of maternal obesity increases surgical risks for both the fetus and mother. Specific risks are identified and strategies to avoid them are evaluated. The prognosis and management of pregnant women who have undergone bariatric surgery is also discussed, and practical guidelines for obstetric management of these patients are presented.

Disorders in blood circulation as a probable cause of death in dogs infected with Babesia canis

Introduction

The purpose of the study was to investigate post-mortem changes in dogs infected with Babesia canis and to establish the probable cause of death of the affected animals.

Material and Methods

Cadavers of six dogs that did not survive babesiosis were collected. Necropsies were performed and samples of various organs were collected for histological examination.

Results

Necropsies and histological examinations revealed congestion and oedemata in various organs. Most of the dogs had ascites, hydrothorax or hydropericardium, pulmonary oedema, pulmonary, renal, hepatic, and cerebral congestion, and necrosis of cardiomyocytes.

Conclusion

These results suggested disorders in blood circulation as the most probable cause of death. However, the pulmonary inflammatory response and cerebral babesiosis observed in some of these dogs could also be considered possible causes of death. This study also showed a possible role for renal congestion in the development of renal hypoxia and azotaemia in canine babesiosis.

Intra-abdominal hypertension and increased acute kidney injury risk: a systematic review and meta-analysis

OBJECTIVE

The present meta-analysis aimed to determine the relationship between intra-abdominal hypertension (IAH) and an increased prevalence of acute kidney injury (AKI) and identify the associated risk factors in various patient populations, regardless of whether they were admitted to an intensive care unit.

METHODS

We used three databases for the following search terms: "IAH," "abdominal compartment syndrome," "AKI," "acute kidney failure," and others. The articles retrieved were compared to identify appropriate studies published until 7 May 2020. The main outcome was AKI.

RESULTS

Six studies with 344 individuals were included. The patients were divided into two main groups: the IAH and non-IAH groups. Compared with patients without IAH, patients with IAH had a higher risk of AKI (odds ratio = 2.57, 95% confidence interval: 1.55-4.26). In the subgroup and meta-regression analyses, body mass index, age, the presence or absence of burns, and cardiac surgery did not affect the risk of AKI.

CONCLUSION

IAH was associated with AKI risk, and this association was not influenced by age, body mass index, the presence or absence of burns, or cardiac surgery.

Pathophysiology of Cardiorenal Syndrome and Use of Diuretics and Ultrafiltration as Volume Control

Acute deterioration in kidney function in the setting of decompensated heart failure, known as cardiorenal syndrome, results from venous congestion. Although diuretics or ultrafiltration are effective measures in decreasing venous congestion and improving symptoms in patients with cardiorenal syndrome, the impact of decongestive therapy on kidney function or mortality remains uncertain. A precise assessment of venous congestion is required to assess the adequacy of patients' response to decongestive therapy and to guide therapeutic decision making.

Acute or chronic dysfunction of the heart or kidneys can cause dysfunction of other organs. This interaction between the heart and kidneys is characterized as cardiorenal syndrome (CRS). Recently, a preponderance of data indicated that venous congestion plays an important role in the combination of renal and cardiac diseases. This review aims to focus on the pathophysiology of venous congestion that leads to renal impairment in heart failure and the use of diuretics or ultrafiltration as decongestive therapy in CRS. We found that although clinical studies have confirmed that decongestive therapy has a definite role in decreasing volume overload and the consequent symptom improvement in patients with CRS, the impact of diuretics or ultrafiltration on the improvement of kidney function or mortality remains uncertain. A precise assessment of volume status is required to determine the adequacy of decongestion. Objective measures of renal venous congestion may be a future metric to assess the adequacy of the diuretic response in patients and guide therapeutic decision making.

Abdominal compartment syndrome among surgical patients

Abdominal compartment syndrome (ACS) develops when organ failure arises secondary to an increase in intraabdominal pressure. The abdominal pressure is determined by multiple factors such as blood pressure, abdominal compliance, and other factors that exert a constant pressure within the abdominal cavity. Several conditions in the critically ill may increase abdominal pressure compromising organ perfusion that may lead to renal and respiratory dysfunction. Among surgical and trauma patients, aggressive fluid resuscitation is the most commonly reported risk factor to develop ACS. Other conditions that have also been identified as risk factors are ascites, hemoperitoneum, bowel distention, and large tumors. All patients with abdominal trauma possess a higher risk of developing intra-abdominal hypertension (IAH). Certain surgical interventions are reported to have a higher risk to develop IAH such as damage control surgery, abdominal aortic aneurysm repair, and liver transplantation among others. Close monitoring of organ function and intra-abdominal pressure (IAP) allows clinicians to diagnose ACS rapidly and intervene with target-specific management to reduce IAP. Surgical decompression followed by temporary abdominal closure should be considered in all patients with signs of organ dysfunction. There is still a great need for more studies to determine the adequate timing for interventions to improve patient outcomes.

Renal dysfunction in cardiovascular diseases and its consequences

It is well known that the heart and kidney and their synergy is essential for hemodynamic homeostasis. Since the early XIX century it has been recognized that cardiovascular and renal diseases frequently coexist. In the nephrological field, while it is well accepted that renal diseases favor the occurrence of cardiovascular diseases, it is not always realized that cardiovascular diseases induce or aggravate renal dysfunctions, in this way further deteriorating cardiac function and creating a vicious circle. In the same clinical field, the role of venous congestion in the pathogenesis of renal dysfunction is at times overlooked. This review carefully quantifies the prevalence of chronic and acute kidney abnormalities in cardiovascular diseases, mainly heart failure, regardless of ejection fraction, and the consequences of renal abnormalities on both organs, making cardiovascular diseases a major risk factor for kidney diseases. In addition, with regard to pathophysiological aspects, we attempt to substantiate the major role of fluid overload and venous congestion, including renal venous hypertension, in the pathogenesis of acute and chronic renal dysfunction occurring in heart failure. Furthermore, we describe therapeutic principles to counteract the major pathophysiological abnormalities in heart failure complicated by renal dysfunction. Finally, we underline that the mild transient worsening of renal function after decongestive therapy is not usually associated with adverse prognosis. Accordingly, the coexistence of cardiovascular and renal diseases inevitably means mediating between preserving renal function and improving cardiac activity to reach a better outcome.

Management of abdominal compartment syndrome in acute pancreatitis

Abdominal compartment syndrome (ACS), defined by the presence of increased intra-abdominal pressure>20mmHg in association with failure of at least one organ system, is a common and feared complication that may occur in the early phase of severe acute pancreatitis (AP). This complication can lead to patient death in the very short term. The goal of this review is to provide the surgeon and intensivist with objective information to help them in their decision-making. In the early phase of severe AP, it is essential to monitor intra-vesical pressure (iVP) to allow early diagnosis of intra-abdominal hypertension or ACS. The treatment of ACS is both medical and surgical requiring close collaboration between the surgical and resuscitation teams. Medical treatment includes vascular volume repletion, prokinetic agents, effective curarization and percutaneous drainage of large-volume ascites. If uncontrolled respiratory or cardiac failure develops or if maximum medical treatment fails, most teams favor performing an emergency xipho-pubic decompression laparotomy with laparostomy. This procedure follows the principles of abbreviated laparotomy as described for abdominal trauma.

Hemodynamically stable oliguric patients usually do not respond to fluid challenge

Objective

To evaluate renal responsiveness in oliguric critically ill patients after a fluid challenge.

Methods

We conducted a prospective observational study in one university intensive care unit. Patients with urine output < 0.5mL/kg/h for 3 hours with a mean arterial pressure > 60mmHg received a fluid challenge. We examined renal fluid responsiveness (defined as urine output > 0.5mL/kg/h for 3 hours) after fluid challenge.

Results

Forty-two patients (age 67 ± 13 years; APACHE II score 16 ± 6) were evaluated. Patient characteristics were similar between renal responders and renal nonresponders. Thirteen patients (31%) were renal responders. Hemodynamic or perfusion parameters were not different between those who did and those who did not increase urine output before the fluid challenge. The areas under the receiver operating characteristic curves were calculated for mean arterial pressure, heart rate, creatinine, urea, creatinine clearance, urea/creatinine ratio and lactate before the fluid challenge. None of these parameters were sensitive or specific enough to predict reversal of oliguria.

Conclusion

After achieving hemodynamic stability, oliguric patients did not increase urine output after a fluid challenge. Systemic hemodynamic, perfusion or renal parameters were weak predictors of urine responsiveness. Our results suggest that volume replacement to correct oliguria in patients without obvious hypovolemia should be done with caution.

Congestive nephropathy: a neglected entity? Proposal for diagnostic criteria and future perspectives

Venous congestion has emerged as an important cause of renal dysfunction in patients with cardiorenal syndrome. However, only limited progress has been made in differentiating this haemodynamic phenotype of renal dysfunction, because of a significant overlap with pre-existing renal impairment due to long-term hypertension, diabetes, and renovascular disease. We propose congestive nephropathy (CN) as this neglected clinical entity. CN is a potentially reversible subtype of renal dysfunction associated with declining renal venous outflow and progressively increasing renal interstitial pressure. Venous congestion may lead to a vicious cycle of hormonal activation, increased intra-abdominal pressure, excessive renal tubular sodium reabsorption, and volume overload, leading to further right ventricular (RV) stress. Ultimately, renal replacement therapy may be required to relieve diuretic-resistant congestion. Effective decongestion could preserve or improve renal function. Congestive acute kidney injury may not be associated with cellular damage, and complete renal function restoration may be a confirmatory diagnostic criterion. In contrast, a persistently low renal perfusion pressure might induce renal dysfunction and histopathological lesions with time. Thus, urinary markers may differ. CN is mostly seen in biventricular heart failure but may also occur secondary to pulmonary arterial hypertension and elevated intra-abdominal pressure. An increase in central venous pressure to >6 mmHg is associated with a steep decrease in glomerular filtration rate. However, the central venous pressure range that can provide an optimal balance of RV and renal function remains to be determined. We propose criteria to identify cardiorenal syndrome subgroups likely to benefit from decongestive or pulmonary hypertension-specific therapies and suggest areas for future research.

Intravesical monitoring of intra-abdominal pressure after renal transplantation in children: A safety and feasibility study

IAH after RTX can threaten graft viability. This study aimed to assess the feasibility and safety of longitudinal IAP measurements as an IAH screening method in children after RTX. A cohort of eight children with a mean ± SD [range] age 9.6 ± 6.2 [2-17] years who underwent RTX and 18 control patients were evaluated between May 2017 and February 2018. We compared longitudinal IAP measurements using a Foley manometer to other clinical monitoring data. In total, 29 IAP measurements were performed in RTX patients and 121 in controls. The mean post-operative IAP was 7.4 ± 4.3 [1-16] mm Hg following RTX and 8.1 ± 3.7 [1-19] mm Hg in controls. We noted IAH in 9 (31%) of 29 IAP measurements after RTX and in 41 (34%) of 121 IAP measurements in controls. No graft dysfunction occurred in RTX patients despite elevated IAP values. The mean ± SD [range] time expenditure for IAP measurement was 2.1 ± 0.4 [0.6-3.2] minutes. No severe complications occurred during the IAP measurements. Analysis of longitudinal IAP measurements demonstrated that IAP measurement is safe and feasible in children recovering from renal transplantation in the PICU.

Intra-abdominal hypertension and abdominal compartment syndrome in patients admitted to the ICU

BACKGROUND

Intra-abdominal hypertension is frequently present in critically ill patients and is an independent predictor for mortality. Risk factors for intra-abdominal hypertension and abdominal compartment syndrome have been widely investigated. However, data are lacking on prevalence and outcome in high-risk patients. Our objectives in this study were to investigate prevalence and outcome of intra-abdominal hypertension and abdominal compartment syndrome in high-risk patients in a prospective, observational, single-center cohort study.

RESULTS

Between March 2014 and March 2016, we included 503 patients, 307 males (61%) and 196 females (39%). Patients admitted to the intensive care unit with a diagnosis of pancreatitis, elective or emergency open abdominal aorta surgery, orthotopic liver transplantation, other elective or emergency major abdominal surgery and trauma were enrolled. One hundred and sixty four (33%) patients developed intra-abdominal hypertension and 18 (3.6%) patients developed abdominal compartment syndrome. Highest prevalence of abdominal compartment syndrome occurred in pancreatitis (57%) followed by orthotopic liver transplantation (7%) and abdominal aorta surgery (5%). Length of intensive care stay increased by a factor 4 in patients with intra-abdominal hypertension and a factor 9 in abdominal compartment syndrome, compared to patients with normal intra-abdominal pressure. Rate of renal replacement therapy was higher in abdominal compartment syndrome (38.9%) and intra-abdominal hypertension (8.2%) compared to patients with normal intra-abdominal pressure (1.2%). Both intensive care mortality and 90-day mortality were significantly higher in intra-abdominal hypertension (4.8% and 15.2%) and abdominal compartment syndrome (16.7% and 38.9%) compared to normal intra-abdominal pressure (1.2% and 7.1%). Body mass index (odds ratio 1.08, 95% confidence interval 1.03-1.13), mechanical ventilation at admission (OR 3.52, 95% CI 2.08-5.96) and Apache IV score (OR 1.03, 95% CI 1.02-1.04) were independent risk factors for the development of intra-abdominal hypertension or abdominal compartment syndrome.

CONCLUSIONS

The prevalence of abdominal compartment syndrome was 3.6% and the prevalence of intra-abdominal hypertension was 33% in this cohort of high-risk patients. Morbidity and mortality increased when intra-abdominal hypertension or abdominal compartment syndrome was present. The patient most at risk of IAH or ACS in this high-risk cohort has a BMI > 30 kg/m² and was admitted to the ICU after emergency abdominal surgery or with a diagnosis of pancreatitis.

Deresuscitation in Patients with Abdominal Sepsis Carries a Lower Mortality Rate and Less Organ Dysfunction than Conservative Fluid Management

Background: The relation between deresuscitative fluid management after the resuscitation phase and clinical outcome in patients with abdominal sepsis is not completely clear. The aim of this study was to assess the contribution of deresuscitative management to death and organ dysfunction in abdominal sepsis. Methods: Consecutive patients with abdominal sepsis requiring fluid resuscitation were included in this study. According to the fluid management given in the later stage of resuscitation, a conservative group and a deresuscitative fluid management group were compared. The primary outcome was in-hospital death, whereas secondary outcomes were categorized as organ dysfunction and other adverse events. Results: A total of 138 patients were enrolled in this study. Conservative fluid management was given to 47.8% of patients, whereas deresuscitative fluid management occurred in 52.2%. The deresuscitative strategy was associated with a markedly lower prevalence of new-onset acute kidney injury and a decrease in the duration of continuous renal replacement therapy (CRRT). There was a greater risk of needing new-onset intubation and the mechanical ventilation duration in the conservative group than in the deresuscitative group. However, the deresuscitative group did not differ from the conservative group with respect to open abdomen and intra-abdominal hypertension or new-onset abdominal compartment syndrome. The conservative treatment was associated with prolonged stays as well as a higher in-hospital mortality rate. A multivariable logistic regression model showed that deresuscitative fluid management imparts a protective effect against in-hospital death (odds ratio 4.343; 95% confidence interva1 1.466-12.866; p = 0.008), whereas septic shock, source control failure, and CRRT duration were associated with a higher mortality rate. Conclusions: Fluid balance achieved using deresuscitative treatment is correlated with better outcomes in patients with abdominal sepsis, indicating that this treatment may be useful as a therapeutic strategy.

Evaluation of Renal Disease in Patients With Cirrhosis

Renal dysfunction in cirrhosis is common and is associated with increased mortality. Identifying and treating reversible causes of renal disease can significantly improve outcomes. The etiology, approach, and evaluation of renal disease in this group of patients is similar to the noncirrhosis patient, with a few specific caveats. Renal disease may be unrelated to the cause of cirrhosis (eg, prerenal acute kidney injury, acute tubular necrosis), occur as a manifestation of the same systemic disease responsible for the liver disease (eg, chronic viral hepatitis B and C infection) or as a consequence of cirrhosis (hepatorenal syndrome). Kidney impairment may be underrecognized in patients with cirrhosis due to over-reliance on creatinine-based glomerular filtration rate equations used in clinical practice. The first steps of evaluation for the renal disease include a thorough medical history to identify the underlying cause of cirrhosis and any potential trigger for renal dysfunction, physical examination, and review of prior laboratory records for baseline renal function. Renal imaging and urinalysis should be performed on all cirrhotic patients with renal dysfunction to establish the presence of urinary obstruction, chronicity and intrinsic renal disease.

Is aggressive intravenous fluid resuscitation beneficial in acute pancreatitis? A meta-analysis of randomized control trials and cohort studies

BACKGROUND

There is conflincting evidence on the intravenous fluid (IVF) strategy for acute pancreatitis (AP). We perform a metaanalysis of the available evidence.

AIM

To investigate if aggressive IVF therapy in AP patients is beneficial to decrease mortality and improve outcomes.

METHODS

Metaanalysis of available randomized controlled trials and cohort studies comparing aggressive IVF vs non-aggressive IVF resuscitation.

RESULTS

There was no significant difference in mortality between the aggressive (n = 1229) and non-aggressive IVF (n = 1397) patients. Patients receiving aggressive IVF therapy had higher risk for acute kidney injury and acute respiratory distress syndrome. There also was no significant difference in the overall incidence of systemic inflammatory response syndrome, persistent organ failure, pancreatic necrosis when comparing both study groups.

CONCLUSION

Early aggressive IVF therapy did not improve mortality. Moreover, aggressive IVF therapy could potentially increase the risk for acute kidney injury and pulmonary edema leading to respiratory failure and mechanical ventilation. Studies are needed to investigate which subset of AP patients could benefit from aggressive IVF therapy.

Right Heart Failure and Cardiorenal Syndrome

Cardiorenal syndrome is a complex interplay of dysregulated heart and kidney interaction that leads to multiorgan system dysfunction, which is not an uncommon occurrence in the setting of right heart failure. The traditional concept of impaired perfusion and forward flow recently has been modified to include the recognition of systemic venous congestion as a contributor, with direct and indirect mechanisms, including elevated renal venous pressure, reduced renal perfusion pressure, increased renal interstitial pressure, tubular dysfunction, splanchnic congestion, and neurohormonal and inflammatory activation. Treatment options beyond diuretics and vasoactive drugs remain limited and lack supportive evidence.

Increased Intra-Abdominal Pressure During Laparoscopic Pneumoperitoneum Enhances Albuminuria via Renal Venous Congestion, Illustrating Pathophysiological Aspects of High Output Preeclampsia

Intra-abdominal hypertension (IAH) causes severe organ dysfunction. Our aim is to evaluate the effect of increased intra-abdominal pressure (IAP) on renal function, hypothesizing that venous congestion may increase proteinuria and fluid retention without endothelial dysfunction. Three urine samples were collected from 32 non-pregnant women undergoing laparoscopic-assisted vaginal hysterectomy (LAVH) and from 10 controls placed in Trendelenburg position for 60 min. Urine sampling was done before (PRE), during or immediately after (PER), and two hours after (POST) the procedure. Urinary albumin, protein and creatinine concentrations were measured in each sample, and ratios were calculated and compared within and between groups. During LAVH, the albumin/creatinine ratio (ACR) increased and persisted POST-procedure, which was not observed in controls. A positive correlation existed between the LAVH duration and the relative change in both ACR and protein/creatinine ratio (PCR) PER- and POST-procedure. Iatrogenic IAH increases urinary ACR and PCR in non-pregnant women via a process of venous congestion. This mechanism might explain the presentation of one specific subtype of late-onset preeclampsia, where no drop of maternal cardiac output is observed.

Effects of low versus standard pressure pneumoperitoneum on renal syndecan-1 shedding and VEGF receptor-2 expression in living-donor nephrectomy: a randomized controlled study

Background

Laparoscopic nephrectomy is a preferred technique for living kidney donation. However, positive-pressure pneumoperitoneum may have an unfavorable effect on the remaining kidney and other distant organs due to inflamed vascular endothelium and renal tubular cell injury in response to increased systemic inflammation. Early detection of vascular endothelial and renal tubular response is needed to prevent further kidney injury due to increased intraabdominal pressure induced by pneumoperitoneum. Transperitoneal laparoscopic living donor nephrectomy represented a human model of mild increasing intraabdominal pressure. This study aimed to assess the effect of increased intraabdominal pressure on vascular endothelium and renal tubular cells by comparing the effects of low and standard pressure pneumoperitoneum on vascular endothelial growth factor receptor-2 (VEGFR-2) expression and the shedding of syndecan-1 as the early markers to a systemic inflammation.

Methods

We conducted a prospective randomized study on 44 patients undergoing laparoscopic donor nephrectomy. Subjects were assigned to standard (12 mmHg) or low pressure (8 mmHg) groups. Baseline, intraoperative, and postoperative plasma interleukin-6, syndecan-1, and sVEGFR-2 were quantified by ELISA. Syndecan-1 and VEGFR-2 expression were assessed immunohistochemically in renal cortex tissue. Renal tubule and peritubular capillary ultrastructures were examined using electron microscopy. Perioperative hemodynamic changes, end-tidal CO₂, serum creatinine, blood urea nitrogen, and urinary KIM-1 were recorded.

Results

The low pressure group showed lower intra- and postoperative heart rate, intraoperative plasma IL-6, sVEGFR-2 levels and plasma syndecan-1 than standard pressure group. Proximal tubule syndecan-1 expression was higher in the low pressure group. Proximal-distal tubules and peritubular capillary endothelium VEGFR-2 expression were lower in low pressure group. The low pressure group showed renal tubule and peritubular capillary ultrastructure with intact cell membranes, clear cell boundaries, and intact brush borders, while standard pressure group showed swollen nuclei, tenuous cell membrane, distant boundaries, vacuolizations, and detached brush borders.

Conclusion

The low pressure pneumoperitoneum attenuated the inflammatory response and resulted in reduction of syndecan-1 shedding and VEGFR-2 expression as the renal tubular and vascular endothelial proinflammatory markers to injury due to a systemic inflammation in laparoscopic nephrectomy.

Trial registration

ClinicalTrials.gov NCT:03219398, prospectively registered on July 17th, 2017.

Factors associated with increased intra-abdominal pressure in patients undergoing cardiac surgery

Background

The aim of this study was to investigate the intra-abdominal pressure changes and risk factors associated with increased intra-abdominal pressure in patients undergoing cardiac surgery.

Methods

Between July 2016 and January 2017, a total of 100 patients (74 males, 26 females; mean age 55.9±14.3 years; range, 19 to 75 years) who underwent cardiac surgery under cardiopulmonary bypass were included in the study. Patients" data including demographic and clinical characteristics and intra- and postoperative data were recorded. Intra-abdominal pressure was measured via a urinary catheter after anesthesia induction, on admission to the intensive care unit, and at postoperative 12 and 24 h. The patients were divided into two groups according to the intraabdominal pressure as Group 1 (≥12 mmHg; n=49) and Group 2 (<12 mmHg; n=51).

Results

In the univariate regression analysis, high intra-abdominal pressure was related to intra-abdominal pressure measured after anesthesia induction (Odds Ratio =0.70, p=0.001), age (odds ratio=0.95, p=0.004), hypertension (odds ratio=4.51, p=0.0001), duration of cardiopulmonary bypass (odds ratio=0.97, p=0.0001), intraoperative lactate levels (odds ratio=0.53, p=0.0001), use of red blood cells (odds ratio=0.24, p=0.0001), use of dopamine (odds ratio=0.21, p=0.002), dobutamine (odds ratio=0.28, p=0.005), use of noradrenaline (odds ratio=0.25, p=0.016), postoperative lactate levels (odds ratio=0.60, p=0.0001), duration of cross-clamp (odds ratio=0.97, p=0.0001), atrial fibrillation (odds ratio=5.89, p=0.004), and acute kidney injury (odds ratio=8.33, p=0.048). In the multivariate analysis, the intra-abdominal pressure at baseline (odds ratio=0.70, p=0.045), age (odds ratio=0.93, p=0.032), hypertension (odds ratio=6.87, p=0.023), duration of cardiopulmonary bypass (odds ratio=0.98, p=0.062), intraoperative lactate levels (odds ratio=0.57, p=0.035), and use of red blood cells (odds ratio=0.19, p=0.003) remained statistically significant.

Conclusion

Our study results suggest that age, hypertension, duration of cardiopulmonary bypass, intraoperative lactate levels, and use of red blood cells are risk factors associated with elevated intra-abdominal pressure in patients undergoing cardiac surgery. Increased awareness of these risk factors and the addition of intra-abdominal pressure measurement to the standard follow-up scheme in patients with variable hemodynamics, low cardiac output, and high lactate levels in the intensive care unit may be useful in early diagnosis of complications and in decreasing morbidity.

A narrative review of the impact of surgery and anaesthesia on acute kidney injury

The epidemiology of peri-operative acute kidney injury varies depending on the definition, type of surgery and acute and chronic comorbidities. Haemodynamic instability, disturbance of the microcirculation, endothelial dysfunction, inflammation and tubular cell injury are the main factors contributing to the pathogenesis. There are no specific therapies. The most effective strategies to protect renal function during the peri-operative period are: the avoidance of nephrotoxic insults; optimisation of haemodynamics; prevention of hypotension; and meticulous fluid management, including avoidance of both hypovolaemia and hypervolaemia. Peri-operative acute kidney injury is associated with an increased risk of short- and long-term postoperative complications, including a longer stay in hospital, development of premature chronic kidney disease and increased mortality. Resource utilisation and healthcare costs are also higher. In future, the development of advanced clinical prediction scores, new imaging and monitoring techniques and the application of new biomarkers for acute kidney injury have the prospect of identifying acute kidney injury earlier and allowing a more personalised management approach with the aim of reducing the global burden of acute kidney injury.

Abdominal Compartment Syndrome: Improving Outcomes With A Multidisciplinary Approach - A Narrative Review

Abdominal compartment syndrome (ACS) refers to a severe increase in intra-abdominal pressure associated with single or multiorgan failure. ACS with specific pathophysiological processes and detrimental outcomes may occur in a variety of clinical conditions. Patients with ACS are predominantly managed in critical care settings, however, a wide range of multidisciplinary interventions are frequently required from medical, surgical, radiological and nursing specialties. The medical management, aiming to prevent the progression of intra-abdominal hypertension to ACS, is extensively reviewed. Timing and techniques of surgical decompression techniques, as well as management of open abdomen, are outlined. In summary, the current narrative review provides data on history, definitions, epidemiology and pathophysiology of the syndrome and highlights the importance of multidisciplinary approach in the management of ACS in adults.