Effect of a single small volume fluid bolus with balanced or un-balanced fluids on chloride and acid-base status: a prospective randomized pilot study (the FLURES-trial).

OBJECTIVE: To compare the short-term effects on acid base, electrolyte status and urine output of a single fluid bolus of saline to that of the balanced solution Plasmalyte® in critically ill patients. METHODS: Prospective, randomized, controlled trial. Adult patients (≥ 18 years) admitted to the ICU receiving a fluid bolus were randomized to receive 1 L of saline (NaCl 0.9%, Baxter) or a balanced fluid [Plasmalyte® (Baxter)]. Blood samples and urine output were collected just before (T0), just after (T1), 2 h after (T2) (only for urinary output) and three hours after termination of the fluid bolus (T4). The effect of fluid boluses on serum chloride, apparent strong ion difference, base excess, urinary output and blood pressure or vasopressor need were analyzed. MAIN RESULTS: Patients who received a 1 L saline fluid bolus had a significant increase in serum chloride (1.60; 95% CI 1.10 to 2.10; P < 0.001) and short-term decrease in apparent strong ion difference (- 1.85; 95% CI - 2.71 to - 0.99; P < 0.001) and base excess (- 0.90; 95% CI - 1.31 to - 0.50; P < 0.001). We observed a 17% increase in patients developing hyperchloremia in the saline group (0.17; 95% CI 0.05 to 0.29; P = 0.005). No significant difference in urinary output, blood pressure or vasopressor need was observed in either group. CONCLUSION: Even a single, small bolus of saline, administered to critically ill patients, causes a significant increase in chloride concentration and a decrease in apparent strong ion difference and base excess, and an increase in the number of patients developing hyperchloremia. No difference in effect on urinary output, blood pressure or vasopressor need was observed between the two groups. EUDRACT NUMBER: 2014-001005-41; date of registration: 28/10/2014. LOCAL EC APPROVAL: EC project number 2014/038.

Report of the first AKI Round Table meeting: an initiative of the ESICM AKI Section.

PURPOSE: Critical Care Nephrology is an emerging sub-specialty of Critical Care. Despite increasing awareness about the serious impact of acute kidney injury (AKI) and renal replacement therapy (RRT), important knowledge gaps persist. This report represents a summary of a 1-day meeting of the AKI section of the European Society of Intensive Care Medicine (ESICM) identifying priorities for future AKI research. METHODS: International Members of the AKI section of the ESICM were selected and allocated to one of three subgroups: "AKI diagnosis and evaluation", "Medical management of AKI" and "Renal Replacement Therapy for AKI." Using a modified Delphi methodology, each group identified knowledge gaps and developed potential proposals for future collaborative research. RESULTS: The following key research projects were developed: Systematic reviews: (a) epidemiology of AKI with stratification by patient cohorts and diagnostic criteria; (b) role of higher blood pressure targets in patients with hypertension admitted to the Intensive Care Unit, and (c) specific clearance characteristics of different modalities of continuous renal replacement therapy (CRRT). Observational studies: (a) epidemiology of critically ill patients according to AKI duration, and (b) current clinical practice of CRRT. Intervention studies:( a) Comparison of different blood pressure targets in critically ill patients with hypertension, and (b) comparison of clearance of solutes with various molecular weights between different CRRT modalities. CONCLUSION: Consensus was reached on a future research agenda for the AKI section of the ESICM.

Saturable elimination of piperacillin in critically ill patients: implications for continuous infusion.

The study aimed to evaluate saturation of piperacillin elimination in critically ill adult patients. Seventeen critically ill adult patients received continuous and intermittent infusion of piperacillin/tazobactam. Piperacillin plasma concentrations (n = 217) were analysed using population pharmacokinetic (PopPK) modelling. Post-hoc simulations were performed to evaluate the type I error rate associated with the study. Unseen data were used to validate the final model. The mean error (ME) and root mean square error (RMSE) were calculated as a measure of bias and imprecision, respectively. A PopPK model with parallel linear and non-linear elimination best fitted the data. The median and 95% confidence interval (CI) for the model parameters drug clearance (CL), volume of central compartment (V), volume of peripheral compartment (Vp) and intercompartmental clearance (Q) were 9 (7.69-11) L/h, 6.18 (4.93-11.2) L, 11.17 (7.26-12) L and 15.61 (12.66-23.8) L/h, respectively. The Michaelis-Menten constant (Km) and the maximum elimination rate for Michaelis-Menten elimination (Vmax) were estimated without population variability in the model to avoid overfitting and inflation of the type I error rate. The population estimates for Km and Vmax were 37.09 mg/L and 353.57 mg/h, respectively. The bias (ME) was -20.8 (95% CI -26.2 to -15.4) mg/L, whilst imprecision (RMSE) was 49.2 (95% CI 41.2-56) mg/L. In conclusion, piperacillin elimination is (partially) saturable. Moreover, the population estimate for Km lies within the therapeutic window and therefore saturation of elimination should be accounted for when defining optimum dosing regimens for piperacillin in critically ill patients.

Prevention of acute kidney injury and protection of renal function in the intensive care unit: update 2017 : Expert opinion of the Working Group on Prevention, AKI section, European Society of Intensive Care Medicine.

BACKGROUND: Acute kidney injury (AKI) in the intensive care unit is associated with significant mortality and morbidity. OBJECTIVES: To determine and update previous recommendations for the prevention of AKI, specifically the role of fluids, diuretics, inotropes, vasopressors/vasodilators, hormonal and nutritional interventions, sedatives, statins, remote ischaemic preconditioning and care bundles. METHOD: A systematic search of the literature was performed for studies published between 1966 and March 2017 using these potential protective strategies in adult patients at risk of AKI. The following clinical conditions were considered: major surgery, critical illness, sepsis, shock, exposure to potentially nephrotoxic drugs and radiocontrast. Clinical endpoints included incidence or grade of AKI, the need for renal replacement therapy and mortality. Studies were graded according to the international GRADE system. RESULTS: We formulated 12 recommendations, 13 suggestions and seven best practice statements. The few strong recommendations with high-level evidence are mostly against the intervention in question (starches, low-dose dopamine, statins in cardiac surgery). Strong recommendations with lower-level evidence include controlled fluid resuscitation with crystalloids, avoiding fluid overload, titration of norepinephrine to a target MAP of 65-70 mmHg (unless chronic hypertension) and not using diuretics or levosimendan for kidney protection solely. CONCLUSION: The results of recent randomised controlled trials have allowed the formulation of new recommendations and/or increase the strength of previous recommendations. On the other hand, in many domains the available evidence remains insufficient, resulting from the limited quality of the clinical trials and the poor reporting of kidney outcomes.

Epidemiology of augmented renal clearance in mixed ICU patients.

BACKGROUND: Augmented renal clearance (ARC) or renal hyperfiltration is increasingly reported in intensive care unit (ICU) patients. The goal of this analysis was to study the epidemiology of ARC in a cohort of mixed ICU patients METHODS: Single center retrospective cohort study of adult ICU patients (12/2008-2/2010). When data were available, urinary creatinine clearance (CLCR) was calculated for all patients throughout their ICU stay. ARC was defined as a body surface adjusted CLCR≥130 mL/min/1.73m2. We sought to study the incidence of ARC and identify patient characteristics associated with ARC. RESULTS: A total of 1081 patients were included in the analysis, generating 4472 ICU patient days. Median age was 62 y (IQR 50-72), and 63% were male. The initial CLCR was 86 (39-151) mL/min and the maximal CLCR was 145 (76-237) mL/min. ARC occurred in 55.8% of patients, and was about as frequent in men and women (37%% vs. 35%%, P=0.73). Patients with ARC were younger (57 vs. 67 years, P<0.001) and were less frequently treated with vasopressors (27% vs. 39%, P<0.01). ARC incidence was 36.6 ARC days per 100 ICU days. ARC throughout the ICU stay occurred in 32.8% of patients. CONCLUSION: ARC was a frequent finding in this cohort of ICU patients, with more than half of the patient expressing ARC at least once during their ICU stay, and an incidence of 36.6 ARC days/100 patient days.

AKI in early sepsis is a continuum from transient AKI without tubular damage over transient AKI with minor tubular damage to intrinsic AKI with severe tubular damage.

PURPOSE: The pathophysiology of septic acute kidney injury (AKI) is incompletely understood, and there is controversy on the role of renal hypoperfusion in early sepsis. We hypothesized that renal hypoperfusion plays a role in early sepsis and that there is a continuum between transient AKI without tubular damage, transient AKI with minor tubular damage, and intrinsic AKI. METHODS: A total of 107 consecutive patients with sepsis were included. Fractional excretion of sodium (FENa), urinary, and serum neutrophil gelatinase-associated lipocalin were measured at admission (T0) and 4 h (T4) and 24 h later (T24). Patients were classified according to FENa quartiles (FENaQ). Transient and intrinsic AKI were respectively defined as AKI that did or did not recover to no AKI in the following 5 days. RESULTS: A total of 57 developed transient AKI, 22 developed intrinsic AKI, and 28 did not have AKI. Of the ten patients with transient AKI classified in the two lowest FENa quartiles (FENa < 0.36 %) and without signs of local tubular damage, seven still did not show signs of tubular damage 24 h later. Also, 50 % of patients with intrinsic AKI classified in the same FENaQ did not show signs of local tubular damage at admission but did so 24 h later. CONCLUSIONS: There is a continuum between transient AKI without tubular damage, transient AKI with minor tubular damage, and intrinsic AKI in sepsis. Renal hypoperfusion seems to be the instigator for the development of AKI in the majority of patients with early sepsis. Other mechanisms in some patients cannot be excluded.

Four phases of intravenous fluid therapy: a conceptual model.

I.V. fluid therapy plays a fundamental role in the management of hospitalized patients. While the correct use of i.v. fluids can be lifesaving, recent literature demonstrates that fluid therapy is not without risks. Indeed, the use of certain types and volumes of fluid can increase the risk of harm, and even death, in some patient groups. Data from a recent audit show us that the inappropriate use of fluids may occur in up to 20% of patients receiving fluid therapy. The delegates of the 12th Acute Dialysis Quality Initiative (ADQI) Conference sought to obtain consensus on the use of i.v. fluids with the aim of producing guidance for their use. In this article, we review a recently proposed model for fluid therapy in severe sepsis and propose a framework by which it could be adopted for use in most situations where fluid management is required. Considering the dose-effect relationship and side-effects of fluids, fluid therapy should be regarded similar to other drug therapy with specific indications and tailored recommendations for the type and dose of fluid. By emphasizing the necessity to individualize fluid therapy, we hope to reduce the risk to our patients and improve their outcome.

Extended versus bolus infusion of meropenem and piperacillin: a pharmacokinetic analysis.

BACKGROUND: Extended infusion of beta-lactam antibiotics has been advocated as a method for optimizing antibiotic exposure in critically ill patients. The objective of this study was to compare the pharmacokinetics/pharmacodynamics of extended infusion versus bolus infusion of piperacillin and meropenem in critically ill patients with normal renal function. METHODS: A prospective study of 3 hours extended infusion of meropenem and piperacillin in critically ill patients without renal dysfunction. Results from the extended infusion cohort were compared to previously published bolus infusion data in critically ill patients. RESULTS: Twenty extended infusion patients (15 piperacillin, 5 meropenem) were compared with 13 bolus infusion patients (8 piperacillin, 5 meropenem). The demographic and clinical characteristics between both groups were not statistically different. Significant pharmacokinetic differences were observed in median (interquartile range) Cmax for both meropenem (extended infusion 17 [12.6-21.9] vs. bolus 85.2 [66.7-140.3]; P=0.01) and piperacillin (extended infusion 76.2 [57.7-92.6] vs. bolus 240.2 [168.5-275.4]; P=0.001). Considerable pharmacokinetic variability existed in each group for both drugs. Compared to bolus infusion, fT>MIC using extended infusion was higher for both drugs: 96% (IQR 71-100%) compared to 77% (IQR 41-93%) for piperacillin (P=0.05) and 82% (IQR 63-89%) compared to 51% (IQR 48-63%) for meropenem (P=0.095); assuming a MIC of 16 mg/L and 2 mg/L respectively. CONCLUSION: This study confirms that extended infusion in critically ill patients result in advantageous pharmacokinetic profiles by increasing the fT>MIC for piperacillin and meropenem. In a significant subpopulation of critically ill patients with normal renal function, a 100% fT>MIC target is not reached, even with 3-hour extended infusions.

Therapeutic drug monitoring-based dose optimisation of piperacillin and meropenem: a randomised controlled trial.

PURPOSE: There is variability in the pharmacokinetics (PK) of antibiotics (AB) in critically ill patients. Therapeutic drug monitoring (TDM) could overcome this variability and increase PK target attainment. The objective of this study was to analyse the effect of a dose-adaption strategy based on daily TDM on target attainment. METHODS: This was a prospective, partially blinded, and randomised controlled trial in patients with normal kidney function treated with meropenem (MEM) or piperacillin/tazobactam (PTZ). The intervention group underwent daily TDM, with dose adjustment when necessary. The predefined PK/pharmacodynamic (PK/PD) target was 100% fT>4MIC [percentage of time during a dosing interval that the free (f) drug concentration exceeded 4 times the MIC]. The control group received conventional treatment. The primary endpoint was the proportion of patients that reached 100% fT>4MIC and 100 % fT>MIC at 72 h. RESULTS: Forty-one patients (median age 56 years) were included in the study. Pneumonia was the primary infectious diagnosis. At baseline, 100% fT>4MIC was achieved in 21% of the PTZ patients and in none of the MEM patients; 100% fT>MIC was achieved in 71% of the PTZ patients and 46 % of the MEM patients. Of the patients in the intervention group, 76 % needed dose adaptation, and five required an additional increase. At 72 h, target attainment rates for 100% fT>4MIC and 100% fT>MIC were higher in the intervention group: 58 vs. 16%, p = 0.007 and 95 vs. 68%, p = 0.045, respectively. CONCLUSIONS: Among critically ill patients with normal kidney function, a strategy of dose adaptation based on daily TDM led to an increase in PK/PD target attainment compared to conventional dosing.

Factors associated with inadequate early vancomycin levels in critically ill patients treated with continuous infusion.

Vancomycin administration using a loading dose and continuous infusion (CI) results in more rapid attainment of adequate concentrations. The aim of this retrospective study of ICU patients receiving vancomycin was to determine the efficacy of a vancomycin dosing protocol using a weight-based loading dose and to identify factors associated with inadequate concentrations. Patients received a loading dose (<65 kg, 1000 mg; ≥65 kg, 1500 mg), and 2000 mg/24 h CI with subsequent dose adaptation. Adequate levels were defined as concentrations ≥15 mg/L. In total, 227 patients (154 males) were included in the study (mean age 56.5 ± 16.1 years; mean APACHE II score 19.30 ± 7.7). The mean loading dose was 1129 ± 369 mg (15.07 ± 4.99 mg/kg). The dosing protocol was applied in 126 patients (55.5%). Mean vancomycin levels were 19.32 mg/L and 21.08 mg/L on Days 2 and 3, respectively. Vancomycin levels on Day 2 were adequate in 70.5% of patients, increasing to 84.1% on Day 3. Patients who received an appropriate loading dose more often had adequate vancomycin levels on Day 2. Older age, female sex, higher creatinine concentration, lower body temperature and use of a loading dose according to the vancomycin dosing protocol were independently associated with adequate vancomycin levels. A weight-based loading dose plus CI of vancomycin resulted in adequate concentrations in most patients and was superior compared with a non-standardised loading dose. Some patients may require higher doses, and factors other than weight, such as kidney function, age and sex, play a role.

Upregulation of CD26 expression in epithelial cells and stromal cells during wound-induced skin tumour formation.

We have previously described InvEE transgenic mice in which non-dividing, differentiating epidermal cells express oncogenically activated MAPK kinase 1 (MEK1). Skin wounding triggers tumour formation in InvEE mice via a mechanism that involves epidermal release of IL-1α and attraction of a pro-tumorigenic inflammatory infiltrate. To look for potential effects on the underlying connective tissue, we screened InvEE and wild-type epidermis for differential expression of cytokines and immune modulators. We identified a single protein, CD26 (dipeptidyl peptidase-4). CD26 serum levels were not increased in InvEE mice. In contrast, CD26 was upregulated in keratinocytes expressing mutant MEK1 and in the epithelial compartment of InvEE tumours, where it accumulated at cell-cell borders. CD26 expression was increased in dermal fibroblasts following skin wounding but was downregulated in tumour stroma. CD26 activity was stimulated by calcium-induced intercellular adhesion in keratinocytes, suggesting that the upregulation of CD26 in InvEE epidermis is due to expansion of the differentiated cell layers. IL-1α treatment of dermal fibroblasts stimulated CD26 activity, and therefore epidermal IL-1α release may contribute to the upregulation of CD26 expression in wounded dermis. Pharmacological blockade of CD26, via Sitagliptin, reduced growth of InvEE tumours, while combined inhibition of IL-1α and CD26 delayed tumour onset and reduced tumour incidence. Our results demonstrate that inappropriate activation of MEK1 in the epidermis leads to changes in dermal fibroblasts that, like the skin inflammatory infiltrate, contribute to tumour formation.

Abdominal decompression for abdominal compartment syndrome in critically ill patients: a retrospective study.

BACKGROUND: The abdominal compartment syndrome (ACS) refers to organ dysfunction that may occur as a result of increased intra-abdominal pressure (IAP). Successful management may require abdominal decompression and temporary abdominal closure (TAC). The aim of this study was to analyze the characteristics of patients requiring abdominal decompression, to describe the methods used for TAC, and to study the outcome of these patients. METHODS: A series of critically ill patients who required abdominal decompression for ACS between January 2000 and March 2007 were reviewed retrospectively. Age, gender, severity of organ dysfunction before decompression and the cause of ACS as well as the type of abdominal closure system and length of ICU-stay were recorded. Definitive abdominal closure and in-hospital mortality were the main outcome parameters. RESULTS: Eighteen patients with primary ACS and 6 with secondary ACS required decompressive Laparotomy. Patients' ages ranged from 18 to 89 years (mean 50.7). The median preoperative IAP was 26 mmHg, and IAP decreased to 13 mmHg after decompressive laparotomy. Organ function, as quantified by the SOFA scoring system, improved significantly after the intervention. Eight patients had immediate primary fascial closure after the decompressive procedure and 16 patients required TAC. The majority of the survivors underwent planned ventral hernia repair at a later stage. The mean length of stay in the ICU was 23 (+/- 16) days. Overall, fifteen patients survived (63%). CONCLUSIONS: Decompressive Laparotomy was effective in reducing IAP and was associated with an improvement in organ function. In most of the patients, the abdomen could not be closed after decompression, and fascial repair was delayed.

Abdominal decompression for intra-abdominal hypertension after simultaneous pancreas-kidney transplantation.

Intra-abdominal hypertension (IAH) is increasingly recognized in critically ill patients and can result in respiratory, hemodynamic or renal dysfunction. We report the case of a patient suffering from diabetic nephropathy who underwent simultaneous pancreas-kidney transplantation. Within 12 h after the operation, the patient developed IAH resulting in oliguria and a rise in serum creatinine. Surgical abdominal decompression was performed, resulting in immediate restoration of kidney graft function.

Service-oriented subscription management of medical decision data in the intensive care unit.

OBJECTIVES: This paper addresses the design of a platform for the management of medical decision data in the ICU. Whenever new medical data from laboratories or monitors is available or at fixed times, the appropriate medical support services are activated and generate a medical alert or suggestion to the bedside terminal, the physician's PDA, smart phone or mailbox. Since future ICU systems will rely ever more on medical decision support, a generic and flexible subscription platform is of high importance. METHODS: Our platform is designed based on the principles of service-oriented architectures, and is fundamental for service deployment since the medical support services only need to implement their algorithm and can rely on the platform for general functionalities. A secure communication and execution environment are also provided. RESULTS: A prototype, where medical support services can be easily plugged in, has been implemented using Web service technology and is currently being evaluated by the Department of Intensive Care of the Ghent University Hospital. To illustrate the platform operation and performance, two prototype medical support services are used, showing that the extra response time introduced by the platform is less than 150 ms. CONCLUSIONS: The platform allows for easy integration with hospital information systems. The platform is generic and offers user-friendly patient/service subscription, transparent data and service resource management and priority-based filtering of messages. The performance has been evaluated and it was shown that the response time of platform components is negligible compared to the execution time of the medical support services.

Costs and length of stay associated with antimicrobial resistance in acute kidney injury patients with bloodstream infection.

INTRODUCTION: Antimicrobial resistance negatively impacts on prognosis. Intensive care unit (ICU) patients, and particularly those with acute kidney injury (AKI), are at high risk for developing nosocomial bloodstream infections (BSI) due to multi-drug-resistant strains. Economic implications in terms of costs and length of stay (LOS) attributable to antimicrobial resistance are underevaluated. This study aimed to assess whether microbial susceptibility patterns affect costs and LOS in a well-defined cohort of ICU patients with AKI undergoing renal replacement therapy (RRT) who developed nosocomial BSI. METHODS: Historical study (1995-2004) enrolling all adult RRT-dependent ICU patients with AKI and nosocomial BSI. Costs were considered as invoiced in the Belgian reimbursement system, and LOS was used as a surrogate marker for hospital resource allocation. RESULTS: Of the 1330 patients with AKI undergoing RRT, 92 had microbiologic evidence of nosocomial BSI (57/92, 62% due to a multi-drug-resistant microorganism). Main patient characteristics were equal in both groups. As compared to patients with antimicro-4 bial-susceptible BSI, patients with antimicrobial-resistant BSI were more likely to acquire Gram-positive infection (72.6% vs 25.5%, P<0.001). No differences were found neither in LOS (ICU before BSI, ICU, hospital before BSI, hospital, hospital after BSI, and time on RRT; all P>0.05) or hospital costs (all P>0.05) when comparing patients with antimicrobial-resistant vs antimicrobial-susceptible BSI. However, although not statistically significant, patients with BSI caused by resistant Gram-negative-, Candida-, or anaerobic bacteria incurred substantial higher costs than those without. CONCLUSION: In a cohort of ICU patients with AKI and nosocomial BSI undergoing RRT, patients with antimicrobial-resistant vs antimicrobial-susceptible Gram-positive BSI did not have longer hospital stays, or higher hospital costs. Patients with resistant "other" (i.e. Gram-negative, Candida, or anaerobic) BSI were found to have a distinct trend towards increased resources use as compared to patients with susceptible "other" BSI, respectively.

Pharmacologic approaches for volume excess in acute kidney injury (AKI).

Volume management is an integral component of the care of patients with acute kidney injury (AKI). Considerable controversy exists regarding the use of pharmacological agents for volume management. Although overt fluid overload is often seen in AKI and may prompt attention for the use of diuretics, often these agents are used in the absence of fluid retention. Over the last decade several new agents have become available for volume removal. We reviewed the literature on this topic and addressed four key questions for the appropriate utilization of these agents. These include the drug targets and mechanism of action of available agents; clinical goals and criteria for timing of intervention; adaptation of therapy for specific clinical settings and measures required for monitoring effectiveness and patient safety. This report details our current knowledge in this area, provides evidence-based clinical practice recommendations where appropriate, and formulates a research agenda to address unanswered questions.

The epidemiology of cardiac surgery-associated acute kidney injury.

PURPOSE: To describe current knowledge on the epidemiology of cardiac surgery-associated acute kidney injury (CSA-AKI) and to formulate recommendations for clinical practice and a research agenda. METHODS: After a modified Delphi analysis by the Acute Dialysis Quality Initiative (ADQI), 4 questions on the epidemiology of CSA-AKI and recommendations for clinical practice and a research agenda were formulated and addressed. RESULTS: Existing studies on CSA-AKI use over 35 different definitions for CSA-AKI. In addition, there may be important differences in patient characteristics and procedures. This explains the significant variations in reported incidence. Most studies report on CSA-AKI as defined by the need for renal replacement therapy. However, even small decreases in kidney function are associated with a worsened outcome. The workgroup formulated the recommendation to use the AKIN consensus criteria for AKI. One should differentiate early CSA-AKI, caused by the procedure, and late CSA-AKI, associated with the procedure. There may be different clinical scenarios: acute on chronic CSA-AKI, AKI prior to CS, and AKI occurring post CS. Risk factors should be differentiated between pre-, intra-, and post-CS, and between patient-, process-, and procedure-related. Endpoints should include both short-term and long-term outcomes. CONCLUSIONS: Existing data on the epidemiology of CSA-AKI are difficult to compare due to variations in definition and patient cohort. A modified Delphi analysis resulted in a series of recommendations for future research on CSA-AKI.

Transvesical intra-abdominal pressure measurement using minimal instillation volumes: how low can we go?

OBJECTIVE: To determine the minimal instillation volume at which an intra-abdominal pressure (IAP) curve can be obtained and to compare this with the IAP measured at 20 ml instilled volume. DESIGN AND SETTING: Prospective cohort study in the Intensive Care Unit of Ghent University Hospital. PATIENTS: Twenty-five critically ill sedated and ventilated patients at risk for intra-abdominal hypertension (IAH). INTERVENTIONS: IAP was measured transvesically using a custom-designed IAP monitoring set. Measurement was started without any additional instillation of saline and was continued at 1-ml increments up to 10 ml. Finally, IAP was measured with 20 ml instillation volume. MEASUREMENTS AND RESULTS: After each instillation an "oscillation test" was performed. The minimal volume at which the oscillation test was positive was recorded. These values were compared to the IAP obtained using 20 ml saline (IAP20 ml). At 2 ml installed saline volume an oscillation curve could be obtained in all patients. Mean IAP2 ml) was 11.2+/-3.2 mmHg, IAP10 ml) 11.4+/-3.7 mmHg, and IAP20 ml) 11.7+/-3.2 mmHg. In four patients (16%) there was a clinically significant difference of 2 mmHg or more between IAP2 ml and IAP20 ml. The mean difference between IAP20 ml) and IAP2 ml was 0.60+/-0.91 mmHg (95% CI 0.22-0.98). CONCLUSIONS: In this sample of patients at risk for IAH 2 ml saline was sufficient for IAP signal transduction. Higher volumes for transvesical IAP measurement resulted in higher pressure readings in some patients.

Semicontinuous intra-abdominal pressure measurement using an intragastric Compliance catheter.

OBJECTIVE: To compare intra-abdominal pressure (IAP) measurements obtained from an intragastric Compliance catheter with the pressure measured directly in the abdominal cavity. DESIGN AND SETTING: Prospective cohort study in an operating room of the Ghent University Hospital PATIENTS: Seven patients undergoing elective laparoscopic cholecystectomy. INTERVENTIONS: IAP was obtained from both an intragastric catheter and directly from the peritoneal cavity at 1-minute intervals in patients undergoing elective cholecystectomy and compared using Bland-Altman analysis. MEASUREMENTS AND RESULTS: In 156 paired measurements obtained from 7 patients the mean difference between IAPgastric and IAPref was 0.12+/-0.70 mmHg (95% CI 0.01-0.23). CONCLUSIONS: IAP measured using an intragastric Compliance catheter reliably reflects the reference IAP in patients undergoing laparoscopic cholecystectomy.