SARS-CoV-2 seroprevalence survey among health care providers in a Belgian public multiple-site hospital.

Although the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic is lasting for more than 1 year, the exposition risks of health-care providers are still unclear. Available evidence is conflicting. We investigated the prevalence of antibodies against SARS-CoV-2 in the staff of a large public hospital with multiple sites in the Antwerp region of Belgium. Risk factors for infection were identified by means of a questionnaire and human resource data. We performed hospital-wide serology tests in the weeks following the first epidemic wave (16 March to the end of May 2020) and combined the results with the answers from an individual questionnaire. Overall seroprevalence was 7.6%. We found higher seroprevalences in nurses [10.0%; 95% confidence interval (CI) 8.9-11.2] than in physicians 6.4% (95% CI 4.6-8.7), paramedical 6.0% (95% CI 4.3-8.0) and administrative staff (2.9%; 95% CI 1.8-4.5). Staff who indicated contact with a confirmed coronavirus disease 2019 (COVID-19) colleague had a higher seroprevalence (12.0%; 95% CI 10.7-13.4) than staff who did not (4.2%; 95% CI 3.5-5.0). The same findings were present for contacts in the private setting. Working in general COVID-19 wards, but not in emergency departments or intensive care units, was also a significant risk factor. Since our analysis points in the direction of active SARS-CoV-2 transmission within hospitals, we argue for implementing a stringent hospital-wide testing and contact-tracing policy with special attention to the health care workers employed in general COVID-19 departments. Additional studies are needed to establish the transmission dynamics.

A Clinician's Guide to Management of Intra-abdominal Hypertension and Abdominal Compartment Syndrome in Critically Ill Patients.

This article is one of ten reviews selected from the Annual Update in Intensive Care and Emergency Medicine 2020. Other selected articles can be found online at https://www.biomedcentral.com/collections/annualupdate2020. Further information about the Annual Update in Intensive Care and Emergency Medicine is available from http://www.springer.com/series/8901.

Nexfin noninvasive continuous hemodynamic monitoring: validation against continuous pulse contour and intermittent transpulmonary thermodilution derived cardiac output in critically ill patients.

INTRODUCTION: Nexfin (Bmeye, Amsterdam, Netherlands) is a noninvasive cardiac output (CO) monitor based on finger arterial pulse contour analysis. The aim of this study was to validate Nexfin CO (NexCO) against thermodilution (TDCO) and pulse contour CO (CCO) by PiCCO (Pulsion Medical Systems, Munich, Germany). PATIENTS AND METHODS: In a mix of critically ill patients (n = 45), NexCO and CCO were measured continuously and recorded at 2-hour intervals during the 8-hour study period. TDCO was measured at 0-4-8 hrs. RESULTS: NexCO showed a moderate to good (significant) correlation with TDCO (R (2) 0.68, P < 0.001) and CCO (R (2) 0.71, P < 0.001). Bland and Altman analysis comparing NexCO with TDCO revealed a bias (± limits of agreement, LA) of 0.4 ± 2.32 L/min (with 36% error) while analysis comparing NexCO with CCO showed a bias (±LA) of 0.2 ± 2.32 L/min (37% error). NexCO is able to follow changes in TDCO and CCO during the same time interval (level of concordance 89.3% and 81%). Finally, polar plot analysis showed that trending capabilities were acceptable when changes in NexCO (ΔNexCO) were compared to ΔTDCO and ΔCCO (resp., 89% and 88.9% of changes were within the level of 10% limits of agreement). CONCLUSION: we found a moderate to good correlation between CO measurements obtained with Nexfin and PiCCO.

Comparison of Bioelectrical Impedance Analysis (BIA)-Derived Parameters in Healthy Volunteers and Critically Ill Patients.

OBJECTIVE: To compare bioelectrical impedance analysis (BIA)-derived parameters in healthy volunteers and critically ill patients and to assess its prognostic value in an ICU patient cohort. DESIGN: Retrospective, observational data analysis. SETTING: Single centre, tertiary-level ICU (Ziekenhuis Netwerk Antwerpen, ZNA Stuivenberg Hospital). PATIENTS: 101 patients and 101 healthy subjects, participants of International Fluid Academy Days. MEASUREMENTS AND MAIN RESULTS: Compared to healthy volunteers, both male and female ICU patients had significantly higher values for total body water (TBW), extracellular water (ECW), extracellular fluid (ECF), plasma, and interstitial fluid volumes. The phase angle was significantly lower and the malnutrition index was significantly higher in ICU patients, regardless of gender. Non-survivors in the ICU had significantly higher extracellular water content (ECW, 50.7 ± 5.1 vs. 48.9 ± 4.3%, p = 0.047) and accordingly significantly lower intracellular water (ICW, 49.2 ± 5.1 vs. 51.1 ± 4.3%, p = 0.047). The malnutrition index was also significantly higher in non-survivors compared to survivors (0.94 ± 0.17 vs. 0.87 ± 0.16, p = 0.048), as was the capillary leak index (ECW/ICW). CONCLUSIONS: Compared to healthy volunteers, this study observed a higher malnutrition index and TBW in ICU patients with an accumulation of fluids in the extracellular compartment. ICU non-survivors showed similar results, indicating that ICU patients and a fortiori non-survivors are generally overhydrated, with increased TBW and ECW, and more undernourished, as indicated by a higher malnutrition index.

A retrospective evaluation of three ethical triage tools for the allocation of ICU resources during the first wave of the COVID-19 pandemic.

PURPOSE: To retrospectively evaluate the effect of ethical triage tools (ETT), designed to streamline the admission of patients during the first wave of the COVID-19 pandemic. We aimed to determine the characteristics and outcomes of the patients who would have been denied admission to the ICU according to these protocols, including the cumulative number of saved ICU days. METHODS: We retrospectively identified the ethical triage status in every patient who was admitted to our 31-bed mixed ICU in Antwerp, Belgium during the first wave of the COVID-19 pandemic, regardless of the reason for admission. This study was possible since the capacity of our ICU had not been threatened, still enabling our usual case-per-case decision. We evaluated three different ETTs that were designed in our and two other hospitals during the COVID-19 pandemic. RESULTS: During the 81-day study period, 182 patients were admitted to the ICU. Of the patients, 9-23% would have been denied ICU admission according to the three assessed ETTs (WBD cohort), responsible for 8-18% (n = 116-257) of the total number of ICU days. Of the WBD patients, 44-55% eventually survived their hospital stay, compared to 71-74% of the patients that would have been allowed admission. Of the WBD patients admitted for respiratory failure due to COVID-19, 18-25% survived, a number that decreased to 0-20% when these patients required mechanical ventilation. CONCLUSION: An ETT effectively reduces ICU bed occupancy but it does not accurately discriminate between survivors and non-survivors, as a substantial percentage of patients who are being denied admission to the ICU would eventually survive their hospital stay.

Intra-abdominal Hypertension and Abdominal Compartment Syndrome.

Increased intra-abdominal pressure (IAP), also referred to as intra-abdominal hypertension (IAH), affects organ function in critically ill patients and may lead to abdominal compartment syndrome (ACS). Although initially described in surgical patients, IAH and ACS also occur in medical patients without abdominal conditions. IAP can be measured easily and reliably in patients through the bladder using simple tools. The effects of increased IAP are multiple, but the kidney is especially vulnerable to increased IAP because of its anatomic position. Although the means by which kidney function is impaired in patients with ACS is incompletely elucidated, available evidence suggests that the most important factor involves alterations in renal blood flow. IAH should be considered as a potential cause of acute kidney injury in critically ill patients; its role in other conditions, such as hepatorenal syndrome, remains to be elucidated. Because several treatment options (both medical and surgical) are available, IAH and ACS should no longer be considered irrelevant epiphenomena of severe illness or critical care. An integrated approach targeting IAH may improve outcomes and decrease hospital costs, and IAP monitoring is a first step toward dedicated IAH management. IAH prevention, most importantly during abdominal surgery but also during fluid resuscitation, may avoid ACS altogether. However, when ACS occurs and medical treatment fails, decompressive laparotomy is the only option.

Prognostic value of bioelectrical impedance analysis for assessment of fluid overload in ICU patients: a pilot study.

INTRODUCTION: The non-invasive analysis of body fluid composition with bio-electrical impedance analysis (BIA) provides additional information allowing for more persona-lised therapy to improve outcomes. The aim of this study is to assess the prognostic value of fluid overload (FO) in the first week of intensive care unit (ICU) stay. MATERIAL AND METHODS: A retrospective, observational analysis of 101 ICU patients. Whole-body BIA measurements were performed, and FO was defined as a 5% increase in volume excess from baseline body weight. RESULTS: Baseline demographic data, including severity scores, were similar in both the fluid overload-positive (FO+, n = 49) patients and in patients without fluid overload (FO-, n = 52). Patients with FO+ had significantly higher cumulative fluid balance during their ICU stay compared to those without FO (8.8 ± 7.0 vs. 5.5 ± 5.4 litres; P = 0.009), VE (9.9 ± 6.5 vs. 1.5 ± 1.5 litres; P < 0.001), total body water (63.0 ± 9.5 vs. 52.8 ± 8.1%; P < 0.001), and extracellular water (27.0 ± 7.3 vs. 19.6 ± 3.7 litres; P < 0.001). The presence of 5%, 7.5%, and 10% fluid overload was directly associated with increased ICU mortality rates. The percentage fluid overload (P = 0.039) was an independent predictor for hospital mortality. CONCLUSIONS: A higher mortality rate in ICU-patients with FO was observed. FO is an independent prognostic factor because neither APACHE-II, SOFA, nor SAPS-II significantly differed on admission between survivors and non-survivors. Further research is needed to confirm these data prospectively and to evaluate whether BIA-guided deresuscitation in the subacute phase will improve mortality rates.

Intravenous fluid therapy in the perioperative and critical care setting: Executive summary of the International Fluid Academy (IFA).

Intravenous fluid administration should be considered as any other pharmacological prescription. There are three main indications: resuscitation, replacement, and maintenance. Moreover, the impact of fluid administration as drug diluent or to preserve catheter patency, i.e., fluid creep, should also be considered. As for antibiotics, intravenous fluid administration should follow the four Ds: drug, dosing, duration, de-escalation. Among crystalloids, balanced solutions limit acid-base alterations and chloride load and should be preferred, as this likely prevents renal dysfunction. Among colloids, albumin, the only available natural colloid, may have beneficial effects. The last decade has seen growing interest in the potential harms related to fluid overloading. In the perioperative setting, appropriate fluid management that maintains adequate organ perfusion while limiting fluid administration should represent the standard of care. Protocols including a restrictive continuous fluid administration alongside bolus administration to achieve hemodynamic targets have been proposed. A similar approach should be considered also for critically ill patients, in whom increased endothelial permeability makes this strategy more relevant. Active de-escalation protocols may be necessary in a later phase. The R.O.S.E. conceptual model (Resuscitation, Optimization, Stabilization, Evacuation) summarizes accurately a dynamic approach to fluid therapy, maximizing benefits and minimizing harms. Even in specific categories of critically ill patients, i.e., with trauma or burns, fluid therapy should be carefully applied, considering the importance of their specific aims; maintaining peripheral oxygen delivery, while avoiding the consequences of fluid overload.

Can the abdominal perimeter be used as an accurate estimation of intra-abdominal pressure?

INTRODUCTION: Intra-abdominal pressure (IAP) is an important parameter and prognostic indicator of the patient's underlying physiologic status. Correct IAP measurement, therefore, is crucial. Most of the direct and indirect techniques are not free from risks and require some time and skills. This study looks at the possibility of using the abdominal perimeter (AP) as a quick estimation for IAP. METHODS: In total, 237 paired measurements were performed in 26 intensive care unit patients. The IAP was measured according to the recommendations of the World Society on Abdominal Compartment Syndrome via an indwelling bladder catheter using a pressure transducer. The AP was defined as the abdominal circumference at its largest point using body marks as reference for consecutive measurements. RESULTS: The male:female ratio was 1:1, age 69.8 +/- 15.2 yrs, Acute Physiology and Chronic Health Evaluation II score 26.5 +/- 9.2, and Simplified Acute Physiology Score II score 58 +/- 15.5. The number of measurements in each patient was 9.4 +/- 4.6. The IAP was 10.8 +/- 4.9 mm Hg, and the AP was 101 +/- 19.2 cm. There was a poor but statistically significant correlation between IAP and AP: AP = 1.8 x IAP + 81.6 (R2 = 0.21, p = 0.04), but the bias was considerable. The correlation was somewhat better between DeltaIAP (the difference between two consecutive IAP measurements) and DeltaAP (the difference between two consecutive AP measurements) in 210 paired measurements: DeltaAP = 0.4 x DeltaIAP + 0.1 (R2 = 0.24, p < 0.0001). The analysis according to Bland and Altman showed that DeltaIAP was almost identical to DeltaAP with a mean difference or bias of 0 +/- 3 (95% confidence interval: -0.4 to 0.4); however, the limits of agreement were large and thus reflect poor agreement. CONCLUSIONS: In view of the poor correlation between IAP and AP, the latter cannot be used as a clinical estimate for IAP. The correlation between DeltaIAP and DeltaAP was somewhat better, meaning that DeltaAP can be used as an estimate of the evolution of IAP over time; however, for making a definite diagnosis of intra-abdominal hypertension or abdominal compartment syndrome, the exact value of IAP needs to be measured.

The impact of body position on intra-abdominal pressure measurement: a multicenter analysis.

OBJECTIVE: Elevated intra-abdominal pressure (IAP) is a frequent cause of morbidity and mortality among the critically ill. IAP is most commonly measured using the intravesicular or "bladder" technique. The impact of changes in body position on the accuracy of IAP measurements, such as head of bed elevation to reduce the risk of ventilator-associated pneumonia, remains unclear. DESIGN: Prospective, cohort study. SETTING: Twelve international intensive care units. PATIENTS: One hundred thirty-two critically ill medical and surgical patients at risk for intra-abdominal hypertension and abdominal compartment syndrome. INTERVENTIONS: Triplicate intravesicular pressure measurements were performed at least 4 hours apart with the patient in the supine, 15 degrees , and 30 degrees head of bed elevated positions. The zero reference point was the mid-axillary line at the iliac crest. MEASUREMENTS AND MAIN RESULTS: Mean IAP values at each head of bed position were significantly different (p < 0.0001). The bias between IAPsupine and IAP15 degrees was 1.5 mm Hg (1.3-1.7). The bias between IAPsupine and IAP30 degrees was 3.7 mm Hg (3.4-4.0). CONCLUSIONS: Head of bed elevation results in clinically significant increases in measured IAP. Consistent body positioning from one IAP measurement to the next is necessary to allow consistent trending of IAP for accurate clinical decision making. Studies that involve IAP measurements should describe the patient's body position so that these values may be properly interpreted.

IAH/ACS: the rationale for surveillance.

Surveillance for intra-abdominal hypertension (IAH) and abdominal compartment syndrome (ACS) should be implemented in every intensive care unit (ICU), because it has been demonstrated that surveillance is effective. Several criteria that have led to the conclusion that IAH/ACS monitoring is of value: First, IAH is a frequent problem in critically ill patients that directly affects function of all organ systems to some degree, and that is associated with considerable mortality. Furthermore, simple tools for intra-abdominal pressure (IAP) monitoring are available, and it can be safely applied without the need for advanced tools. Finally, both ACS and IAH can be treated with either medical or surgical interventions. Treatment for IAH/ACS should be selected on the basis of the severity of symptoms and the cause of IAH. IAP monitoring should also be incorporated in the daily ICU management of the patient.

In vitro validation of a novel method for continuous intra-abdominal pressure monitoring.

OBJECTIVE: Intra-abdominal pressure (IAP) measurement is important in daily clinical practice. Most measurement techniques vary in automaticity and reproducibility. This study tested a new fully automated continuous technique for IAP measurement, the CiMON. METHODS: Three IAP measurement catheters (a Foley manometer and two balloon-tipped catheters) contained in a 50-ml infusion bag were placed on the bottom of a half open 3-l container. To simulate IAH the container was filled with water using 5 cmH2O increments (0-30 cmH2O). Pressure was estimated by observers using the Foley manometer (IAP(FM)) and simultaneously recorded using two IAP monitors: IAP(spie) with Spiegelberg and IAP(CiM) with CiMON. Observers were blinded to the reference levels. Fifteen observers (three intensivists, four residents, two medical students, and six nurses) conducted three pressure readings at each of the seven pressure levels with the FM technique, giving 315 readings. These were paired with the automated IAP(spie) and IAP(CiM) readings and the height of the H2O column. RESULTS: The intra- and interobserver coefficients of variation (COVA) were low for all methods. There was no difference in the results between specialists, physicians in training, andnurses. Spearman's correlation coefficient (R2) values for all paired measurements were greater than 0.9, and Bland-Altman analysis comparing the reference H2O column, IAP(FM), and IAP(spie) to IAP(CiM) showed a very good agreement at all pressure levels (bias -0.1+/-0.6 cmH2O, 95%CI -0.2 to 0). There was a consistent, low underestimation of the reference H2O pressure by the Spiegelberg technique and a low overestimation at pressures below 20 cmH2O by both other techniques. CONCLUSIONS: All three measurement techniques, IAP(FM), IAP(spie), and IAP(CiM) have good agreement with the applied hydrostatic pressure in this in vitro model of IAP measurement.

The effect of different reference transducer positions on intra-abdominal pressure measurement: a multicenter analysis.

OBJECTIVE: To investigate the effect of different reference transducer positions on intra-abdominal pressure (IAP) measurement. Three reference levels were studied: the symphysis pubis; the phlebostatic axis; and the midaxillary line at the level of the iliac crest. DESIGN: Prospective cohort study. SETTING: The intensive care units of participating hospitals PATIENTS AND PARTICIPANTS: One hundred thirty-two critically ill patients at risk for intra-abdominal hypertension (IAH). INTERVENTIONS: In each patient, three sets of IAP measurements were obtained in the supine position, using the different reference levels. The IAP measurements obtained at the different reference levels were compared using a paired t-test and Bland-Altman statistics were calculated. MEASUREMENTS AND RESULTS: IAP(phlebostatic) (9.9 +/- 4.67 mmHg) and IAP(pubis) (8.4 +/- 4.60 mmHg) were significantly lower that IAP(midax) (12.2 +/- 4.66 mmHg; p < 0.0001 for both comparisons). The bias between the IAP(midax) and IAP(pubis) was 3.8 mmHg (95% CI 3.5-4.1) and 2.3 mmHg (95% CI 1.9-2.6) between the IAP(midax) and the IAP(phlebostatic). The precision was 3.03 and 3.40, respectively. CONCLUSIONS: In the supine position, IAP(midax) is higher than both IAP(phlebostatic) and IAP(pubis), differences found to be clinically significant; therefore, the symphysis pubis or phlebostatic axis reference lines are not interchangeable with the midaxillary level.

Current insights in intra-abdominal hypertension and abdominal compartment syndrome: open the abdomen and keep it open!

BACKGROUND AND AIMS: The abdominal compartment syndrome (ACS) is associated with organ dysfunction and mortality in critically ill patients. Furthermore, the deleterious effects of increased IAP have been shown to occur at levels of intra-abdominal pressure (IAP) previously deemed to be safe. The aim of this article is to provide an overview of all aspects of this underrecognized pathological syndrome for surgeons. METHODS AND CONTENTS: This review article will focus primarily on the recent literature on ACS as well as the definitions and recommendations published by the World Society for the Abdominal Compartment Syndrome. The definitions regarding increased IAP will be listed, followed by a brief but comprehensive overview of the different mechanisms of organ dysfunction associated with intra-abdominal hypertension (IAH). Measurement techniques for IAP will be discussed, as well as recommendations for organ function support in patients with IAH. Finally, surgical treatment and management of the open abdomen are briefly discussed, as well as some minimally invasive techniques to decrease IAP. CONCLUSIONS: The ACS was first described in surgical patients with abdominal trauma, bleeding, or infection, but in recent years ACS has also been described in patients with other pathologies such as burn injury and sepsis. Some of these so-called nonsurgical patients will require surgery to treat their ACS. This review article is intended to provide surgeons with a clear insight into the current state of knowledge regarding IAH, ACS, and the impact of IAP on the critically ill patient.

The effect of neuromuscular blockers in patients with intra-abdominal hypertension.

OBJECTIVE: The objective was to prospectively study the effect of neuromuscular blockers on intra-abdominal pressure (IAP) and a number of physiological variables in patients with increased IAP. DESIGN: Prospective cohort study. SETTING: Intensive care unit of the Ghent University Hospital. PATIENTS AND PARTICIPANTS: Ten critically ill patients with intra-abdominal hypertension (IAH). INTERVENTIONS: An intravenous bolus of cisatracurium at a dose of 0.15 mg/kg was administered, and IAP was measured just before administration and then at 15, 30, 60 and 120 min. The effect of cisatracurium on central venous pressure (CVP), mean arterial pressure (MAP), abdominal perfusion pressure (APP) and heart rate (HR) was also evaluated. Urinary output was recorded prior to administration and after 60 and 120 min. MEASUREMENTS AND RESULTS: The median age of the patients was 50 years (interquartile range 38-65); five of them were male. APACHE II score on admission was 29 (IQR 14-37). IAH was caused by massive fluid resuscitation without obvious abdominal problem in five patients, by abdominal trauma in three, and by burns and bowel distension in one patient each. Bolus administration of cisatracurium significantly decreased IAP from 18 mmHg (16-20) at baseline to 14 mmHg (12-16) at 15 min (p = 0.01) and to 14 mmHg (13-17) at 30 min (p = 0.02). MAP, APP, CVP and HR remained unchanged. No significant effect on urinary output was observed. In all patients, IAP returned to the baseline level after 2 h. CONCLUSIONS: Bolus administration of cisatracurium can be used to temporarily reduce IAP in patients with IAH.

Incidence and prognosis of intra-abdominal hypertension and abdominal compartment syndrome in severely burned patients: Pilot study and review of the literature.

BACKGROUND: Burn patients are at high risk for secondary intra-abdominal hypertension (IAH) and abdominal compartment syndrome (ACS) due to capillary leak and large volume fluid resuscitation. Our objective was to examine the incidence the incidence of IAH and ACS and their relation to outcome in mechanically ventilated (MV) burn patients. METHODS: This observational study included all MV burn patients admitted between April 2007 and December 2009. Various physiological parameters, intra-abdominal pressure (IAP) measurements and severity scoring indices were recorded on admission and/or each day in ICU. Transpulmonary thermodilution parameters were also obtained in 23 patients. The mean and maximum IAP during admission was calculated. The primary endpoint was ICU (burn unit) mortality. RESULTS: Fifty-six patients were included. The average Simplified Acute Physiology Score (SAPS II) and Sequential Organ Failure Assessment (SOFA) scores were 43.4 (± 15.1) and 6.4 (± 3.4), respectively. The average total body surface area (TBSA) affected by burns was 24.9% (± 24.9), with 33 patients suffering inhalational injuries. Forty-four (78.6%) patients developed IAH and 16 (28.6%) suffered ACS. Patients with ACS had higher TBSAs burned (35.8 ± 30 vs. 20.6 ± 21.4%, P = 0.04) and higher cumulative fluid balances after 48 hours (13.6 ± 16L vs. 7.6 ± 4.1 L, P = 0.03). The TBSA burned correlated well with the mean IAP (R = 0.34, P = 0.01). Mortality was notably high (26.8%) and significantly higher in patients with IAH (34.1%, P = 0.014) and ACS (62.5%, P < 0.0001). Most patients received more fluids than calculated by the Parkland Consensus Formula while, interestingly, non-survivors received less. However, when patients with pure inhalation injury were excluded there were no differences. Non-surgical interventions (n = 24) were successful in removing body fluids and were related to a significant decrease in IAP, central venous pressure (CVP) and an improvement in oxygenation and urine output. Non-resolution of IAH was associated with a significantly worse outcome (P < 0.0001). CONCLUSION: Based on our preliminary results we conclude that IAH and ACS have a relatively high incidence in MV burn patients compared to other groups of critically ill patients. The percentage of TBSA burned correlates with the mean IAP. The combination of high CLI, positive (daily and cumulative) fluid balance, high IAP, high EVLWI and low APP suggest a poor outcome. Non-surgical interventions appear to improve end-organ function. Non-resolution of IAH is related to a worse outcome.

What's new in medical management strategies for raised intra-abdominal pressure: evacuating intra-abdominal contents, improving abdominal wall compliance, pharmacotherapy, and continuous negative extra-abdominal pressure.

In the future, medical management may play an increasingly important role in the prevention and management of intra-abdominal hypertension (IAH). A review of different databases was used (PubMed, MEDLINE and EMBASE) with the search terms 'Intra-abdominal Pressure' (IAP), 'IAH', ' Abdominal Compartment Syndrome' (ACS), 'medical management' and 'non-surgical management'. We also reviewed all papers with the search terms 'IAH', 'IAP' and 'ACS' over the last three years, only extracting those papers which showed a novel approach in the non-surgical management of IAH and ACS.IAH and ACS are associated with increased morbidity and mortality. Non-surgical management is an important treatment option in critically ill patients with raised IAP. There are five medical treatment options to be considered to reduce IAP: 1) improvement of abdominal wall compliance; 2) evacuation of intra-luminal contents; 3) evacuation of abdominal fluid collections; 4) optimisation of fluid administration; and 5) optimisation of systemic and regional perfusion. This paper will review the first three treatment arms of the WSACS algorithm: abdominal wall compliance; evacuation of intra-luminal contents and evacuation of abdominal fluid collections. Emerging medical treatments will be analysed and finally some alternative specific treatments will be assessed. Other treatment options with regard to optimising fluid administration and systemic and regional perfusion will be described elsewhere, and are beyond the scope of this review. Medical management of critically ill patients with raised IAP should be instigated early to prevent further organ dysfunction and to avoid progression to ACS. Many treatment options are available and are often part of routine daily management in the ICU (nasogastric, rectal tube, prokinetics, enema, sedation, body position). Some of the newer treatments are very promising options in specific patient populations with raised IAP. Future studies are warranted to confirm some of these findings.

Fluid therapy and perfusional considerations during resuscitation in critically ill patients with intra-abdominal hypertension.

Intra-abdominal hypertension (IAH) and abdominal compartment syndrome (ACS) are consistently associated with morbidity and mortality among the critically ill or injured. Thus, avoiding or potentially treating these conditions may improve patient outcomes. With the aim of improving the outcomes for patients with IAH/ACS, the World Society of the Abdominal Compartment Syndrome recently updated its clinical practice guidelines. In this article, we review the association between a positive fluid balance and outcomes among patients with IAH/ACS and how optimisation of fluid administration and systemic/regional perfusion may potentially lead to improved outcomes among this patient population.Evidence consistently associates secondary IAH with a positive fluid balance. However, despite increased research in the area of non-surgical management of patients with IAH and ACS, evidence supporting this approach is limited. Some evidence exists to support implementing goal-directed resuscitation protocols and restrictive fluid therapy protocols in shocked and recovering critically ill patients with IAH. Data from animal experiments and clinical trials has shown that the early use of vasopressors and inotropic agents is likely to be safe and may help reduce excessive fluid administration, especially in patients with IAH. Studies using furosemide and/or renal replacement therapy to achieve a negative fluid balance in patients with IAH are encouraging. The type of fluid to be administered in patients with IAH remains far from resolved. There is currently insufficient evidence to recommend the use of abdominal perfusion pressure as a resuscitation endpoint in patients with IAH. However, it is important to recognise that IAH either abolishes or increases threshold values for pulse pressure variation and stroke volume variation to predict fluid responsiveness, while the presence of IAH may also result in a false negative passive leg raising test.Correct fluid therapy and perfusional support during resuscitation form the cornerstone of medical management in patients with abdominal hypertension. Controlled studies determining whether the above medical interventions may improve outcomes among those with IAH/ACS are urgently required.

Awareness and knowledge of intra-abdominal hypertension and abdominal compartment syndrome: results of an international survey.

BACKGROUND: Surveys have demonstrated a lack of physician awareness of intra-abdominal hypertension and abdominal compartment syndrome (IAH/ACS) and wide variations in management of these conditions, with many intensive care units (ICUs) reporting that they do not measure intra-abdominal pressure (IAP). We sought to determine the association between publication of the 2006/2007 World Society of the Abdominal Compartment Syndrome (WSACS) Consensus Definitions and Guidelines and IAH/ACS clinical awareness and management. METHODS: The WSACS Executive Committee created an interactive online survey with 53 questions, accessible from November 2006 until December 2008. The survey was endorsed by the WSACS, the European Society of Intensive Care Medicine (ESICM) and the Society of Critical Care Medicine (SCCM). A link to the survey was emailed to all members of the supporting societies. Participants of the 3rd World Congress on Abdominal Compartment Syndrome meeting (March 2007, Antwerp, Belgium) were also asked to complete the questionnaire. No reminders were sent. Based on 13 knowledge questions an overall score was calculated (expressed as percentage). RESULTS: A total of 2244 of the approximately 10,000 clinicians sent the survey responded (response rate, 22.4%). Most of the 2244 respondents (79.2%) completing the survey were physicians or physicians in training and the majority were residing in North America (53.0%). The majority of responders (85%) were familiar with IAP/IAH/ACS, but only 28% were aware of the WSACS consensus definitions for IAH/ACS. Three quarters of respondents considered the cut-off for IAH to be at least 15 mm Hg, and nearly two thirds believed the cut-off for ACS was higher than the currently suggested consensus definition (20 mm Hg). In 67.8% of respondents, organ dysfunction was only considered a problem with IAP of 20 mm Hg or higher. IAP was measured most frequently via the bladder (91.9%), but the majority reported that they instilled volumes well above the current guidelines. Surgical decompression was frequently used to treat IAH/ACS, whereas medical management was only attempted by about half of the respondents. Decisions to decompress the abdomen were predominantly based on the severity of IAP elevation and presence of organ dysfunction (74.4%). Overall knowledge scores were low (43 ± 15%), respondents that were aware of the WSACS had a better score compared to those who were not (49.6% vs. 38.6%, P < 0.001). CONCLUSIONS: This survey showed that although most responding clinicians claim to be familiar with IAH and ACS, knowledge of published consensus definitions, measurement techniques, and clinical management are inadequate.