Interdisciplinary perspectives on computed tomography in sepsis: survey among medical doctors at a large university medical center

OBJECTIVES

This study aims to describe physicians' perspectives on the use of computed tomography (CT) in patients with sepsis.

METHODS

In January 2022, physicians of a large European university medical center were surveyed using a web-based questionnaire asking about their views on the role of CT in sepsis. A total of 371 questionnaires met the inclusion criteria and were analyzed using work experience, workplace, and medical specialty of physicians as variables. Chi-square tests were performed.

RESULTS

Physicians considered the ability to detect an unknown focus as the greatest benefit of CT scans in sepsis (70.9%, n = 263/371). Two clinical criteria - "signs of decreased vigilance" (89.2%, n = 331/371) and "increased catecholamine demand" (84.7%, n = 314/371) - were considered highly relevant for a CT request. Elevated procalcitonin (82.7%, n = 307/371) and lactate levels (83.6%, n = 310/371) were consistently found to be critical laboratory values to request a CT. As long as there is evidence of infection in one organ region, most physicians (42.6%, n = 158/371) would order a CT scan based on clinical assessment. Combined examination of the chest, abdomen, and pelvis was favored (34.8%, n = 129/371) in cases without clinical clues of an infection source. A time window of ≥ 1-6 h was preferred for both CT examinations (53.9%, n = 200/371) and CT-guided interventions (59.3%, n = 220/371) in patients with sepsis.

CONCLUSION

Despite much consensus, there are significant differences in attitudes towards the use of CT in septic patients among physicians from different workplaces and medical specialties. Knowledge of these perspectives may improve patient management and interprofessional communication.

KEY POINTS

Despite interdisciplinary consensus on the use of CT in sepsis, statistically significant differences in the responses are apparent among physicians from different workplaces and medical specialties. The detection of a previously unknown source of infection and the ability to plan interventions and/or surgery based on CT findings are considered key advantages of CT in septic patients. Timing of CT reflects the requirements of specific disciplines.

Impact of Continuous Veno-Venous HemoDiALYsis with Regional Citrate Anticoagulation on Non-NUTRItional Calorie Balance in Patients on the ICU-The NUTRI-DAY Study

Background: Malnutrition as well as overfeeding can have negative impacts on clinical outcomes in critically ill patients. Continuous veno-venous hemodialysis (CVVHD) with regional citrate anticoagulation (RCA) using trisodium citrate 4% (TSC) might play a role in nutrient disposition in patients in the ICU. Methods: In 33 consecutive patients on CVVHD with RCA, energy uptake or loss was calculated. Three macronutrients (lactate, glucose and citrate) were analyzed by taking prefilter blood and effluent samples. Results: Glucose and lactate clearance through CVVHD made up for a loss of 61 kcal/d (IQR 25−164 kcal/d) and 38 kcal/d (IQR 23−59 kcal/d), respectively. Two patients with hyperglycemic state (>350 mg/dL) lost around 600 kcal/d during CVVHD. Net post-filter citrate caloric delivery through RCA was 135 kcal/d (IQR: 124−144 kcal/d). Adding the three macronutrients, net caloric gain through CVVHD was 10 kcal/d (IQR: −63−75 kcal/d). Conclusion: In non-hyperglycemic patients on CVVHD with RCA, the metabolic contribution of the three macronutrients lactate, glucose and citrate is neglectable.

[Hypo- and hypernatremia in the intensive care unit : Pitfalls in volume management]

Hypo- and hypernatremias are very frequent in intensive care unit (ICU) patients and are closely related to volume disturbances and volume management in the ICU. They are associated with longer ICU stays and significant increases in mortality. Treating them is more complex than it may initially appear. Hyponatremias are differentiated based on tonicity and volume status. With hypertonic and isotonic hyponatremias, the primary focus of treatment is the underlying hyperglycemia. In case of hypotonic hypovolemic hyponatremia, the condition is treated with balanced crystalloid solutions. In eu-/hypervolemic hypotonic hyponatremias acute treatment with hypertonic saline is necessary. Hypervolemic hypernatremia occurs almost exclusively in ICU patients, often due to infusion of hypertonic solutions. There is little evidence to guide treatment, although hypotonic infusions in conjunction with diuretics may represent a legitimate approach. Great emphasis should be placed on prevention and the infusion of hypertonic solutions should be avoided. Disturbances in plasma sodium concentrations are common, requiring close attention. Exact diagnostic classification needs to be made and volume managed accordingly.

Non-invasive Oscillometry-Based Estimation of Cardiac Output - Can We Use It in Clinical Practice?

While invasive thermodilution techniques remain the reference methods for cardiac output (CO) measurement, there is a currently unmet need for non-invasive techniques to simplify CO determination, reduce complications related to invasive procedures required for indicator dilution CO measurement, and expand the application field toward emergency room, non-intensive care, or outpatient settings. We evaluated the performance of a non-invasive oscillometry-based CO estimation method compared to transpulmonary thermodilution. To assess agreement between the devices, we used Bland–Altman analysis. Four-quadrant plot analysis was used to visualize the ability of Mobil-O-Graph (MG) to track CO changes after a fluid challenge. Trending analysis of CO trajectories was used to compare MG and PiCCO^® calibrated pulse wave analysis over time (6 h). We included 40 patients from the medical intensive care unit at the Charité – Universitätsmedizin Berlin, Campus Benjamin Franklin between November 2019 and June 2020. The median age was 73 years. Forty percent of the study population was male; 98% was ventilator-dependent and 75% vasopressor-dependent at study entry. The mean of the observed differences for the cardiac output index (COI) was 0.7 l^∗min^–1*m^–2 and the lower, and upper 95% limits of agreement (LOA) were -1.9 and 3.3 l^∗min^–1*m^–2, respectively. The 95% confidence interval for the LOA was ± 0.26 l^∗min^–1*m^–2, the percentage error 83.6%. We observed concordant changes in CO with MG and PiCCO^® in 50% of the measurements after a fluid challenge and over the course of 6 h. Cardiac output calculation with a novel oscillometry-based pulse wave analysis method is feasible and replicable in critically ill patients. However, we did not find clinically applicable agreement between MG and thermodilution or calibrated pulse wave analysis, respectively, assessed with established evaluation routine using the Bland–Altman approach and with trending analysis methods. In summary, we do not recommend the use of this method in critically ill patients at this time. As the basic approach is promising and the CO determination with MG very simple to perform, further studies should be undertaken both in hemodynamically stable patients, and in the critical care setting to allow additional adjustments of the underlying algorithm for CO estimation with MG.

Fluconazole Increases Osmotic Water Transport in Renal Collecting Duct through Effects on Aquaporin-2 Trafficking

BACKGROUND

Arginine-vasopressin (AVP) binding to vasopressin V2 receptors promotes redistribution of the water channel aquaporin-2 (AQP2) from intracellular vesicles into the plasma membrane of renal collecting duct principal cells. This pathway fine-tunes renal water reabsorption and urinary concentration, and its perturbation is associated with diabetes insipidus. Previously, we identified the antimycotic drug fluconazole as a potential modulator of AQP2 localization.

METHODS

We assessed the influence of fluconazole on AQP2 localization in vitro and in vivo as well as the drug's effects on AQP2 phosphorylation and RhoA (a small GTPase, which under resting conditions, maintains F-actin to block AQP2-bearing vesicles from reaching the plasma membrane). We also tested fluconazole's effects on water flow across epithelia of isolated mouse collecting ducts and on urine output in mice treated with tolvaptan, a VR2 blocker that causes a nephrogenic diabetes insipidus-like excessive loss of hypotonic urine.

RESULTS

Fluconazole increased plasma membrane localization of AQP2 in principal cells independent of AVP. It also led to an increased AQP2 abundance associated with alterations in phosphorylation status and ubiquitination as well as inhibition of RhoA. In isolated mouse collecting ducts, fluconazole increased transepithelial water reabsorption. In mice, fluconazole increased collecting duct AQP2 plasma membrane localization and reduced urinary output. Fluconazole also reduced urinary output in tolvaptan-treated mice.

CONCLUSIONS

Fluconazole promotes collecting duct AQP2 plasma membrane localization in the absence of AVP. Therefore, it might have utility in treating forms of diabetes insipidus (e.g., X-linked nephrogenic diabetes insipidus) in which the kidney responds inappropriately to AVP.

Nurse-Directed Blood Glucose Management in a Medical Intensive Care Unit

BACKGROUND

Insulin-delivery algorithms for achieving glycemic control in the intensive care unit require frequent checks of blood glucose level and thus increase nursing workload. Hypoglycemia is a serious complication associated with intensive insulin therapy.

OBJECTIVES

To evaluate a nurse-directed protocol for blood glucose management that allows individualized insulin delivery within a predefined blood glucose corridor, intended to avoid hypoglycemia while maintaining adequate control of blood glucose level without increasing nursing workload.

METHODS

A nurse-directed protocol for blood glucose management was developed by an interprofessional team, and the protocol's performance was investigated in 175 patients compared with 384 historical controls.

RESULTS

With the nurse-directed protocol, hypoglycemia incidents declined significantly (31% vs 12%, P < .001), and minimum blood glucose levels increased significantly (80 mg/dL vs 93 mg/dL, P < .001). Mean and maximum blood glucose levels, the proportion of glucose readings within the target range (31% vs 26%, P = .06), and the number of blood glucose checks (59 vs 58, P = .85) remained unchanged with use of the protocol.

CONCLUSION

Implementation of the nurse-directed protocol for blood glucose management did not increase nursing workload but reduced hypoglycemia incidents significantly while maintaining adequate glycemic control.

Noninvasive oscillometric cardiac output determination in the intensive care unit - comparison with invasive transpulmonary thermodilution

Assessment of the cardiac output (CO) is usually performed with invasive techniques requiring specialized equipment in the intensive care unit (ICU). With TEL-O-GRAPH (TG), CO can be derived from the oscillometrically obtained brachial pulse wave during the measurement of brachial blood pressure. CO and stroke volume (SV) determinations with TG were compared with transpulmonary thermodilution measurements with the PICCO system (PICCO) in 38 haemodynamically unstable ICU patients with a total of 84 comparison measurements performed. SV (33.3 ± 9.0 ml/m² vs. 44.3 ± 14.4 ml/m², p < 0.001) and CO (2.7 ± 0.5 l/min/m² vs. 3.8 ± 1.2 l/min/m², p < 0.001) were underestimated significantly with TG and oscillometric brachial systolic blood pressure (BP) was significantly lower and diastolic BP significantly higher than invasive femoral artery pressure. A linear correlation was found between CO dimension and CO underestimation with TG. Correct tracking of CO changes with a fluid challenge was possible in 69.5% of measurements. Oscillometric noninvasive CO is possible in the ICU, but accuracy and precision of this new method are lacking. Implementation of a correction factor accounting for the linear increase in CO underestimation observed with increasing CO could improve CO assessment with TG in haemodynamically unstable patients.

Analysis of Transpulmonary Thermodilution Data Confirms the Influence of Renal Replacement Therapy on Thermodilution Hemodynamic Measurements

BACKGROUND

Transpulmonary thermodilution (TPTD) is used frequently in the intensive care unit to determine cardiac index (CI), intrathoracic blood volume index (ITBVI), and extravascular lung volume index (EVLWI). Renal replacement therapy (RRT) influences TPTD results, but the underlying mechanisms are not completely understood. We hypothesized that RRT blood flow induces errors in TPTD measurements.

METHODS

We analyzed TPTD data available from the PiCCO® plus hemodynamic measurement device on a personal computer using a proprietary Pulsion Medical Systems software. By using the dialysis catheter to inject the thermal indicator, 20 measurement series were performed in 12 intensive care unit patients determining CI, ITBVI, and EVLWI during RRT with the blood pump stopped, and at flows of 100 and 200 mL/min, respectively.

RESULTS

Data export was successful in 17 measurement series and showed a significant decrease in measured CI (6.5 ± 2.5 vs 5.4 ± 1.9 L/min/m, P < 0.001) and ITBVI (1358.8 ± 274.5 vs 1132.8 ± 218.3 mL/m, P < 0.001) with RRT and a significant increase in EVLWI (8.6 ± 4.4, 10.2 ± 4.5 mL/kg, P < 0.001). Blood temperature before and the temperature decrease after injection of the thermal indicator were unchanged by RRT. Mean transit time and downslope time of the thermodilution curve, however, were both increased with the RRT blood pump running (P ≤ 0.001).

CONCLUSIONS

Analysis of TPTD data shows that thermodilution curve forms are modified with RRT, resulting in an erroneous calculation of thermodilution-derived hemodynamic parameters.

Changes in volumetric hemodynamic parameters induced by fluid removal on hemodialysis in critically ill patients

Management of volume status is difficult in critically ill patients with renal failure. Volumetric hemodynamic indices are increasingly being used to guide fluid therapy in the intensive care unit (ICU), but are not established to monitor hemodialysis-induced fluid removal in critically ill patients. Using volumetric hemodynamic monitoring, changes in extravascular lung water index (EVLWI) and intrathoracic blood volume index (ITBVI) were measured immediately before and after hemodialysis sessions in 35 ICU patients. Additional hemodynamic and oxygenation related parameters were recorded at the same time, and online relative blood volume (RBV) monitoring was performed during hemodialysis. EVLWI decreased significantly with fluid removal (median 10.0 vs. 9.6 mL/kg, P = 0.001), whereas ITBVI remained stable (median 1012 vs. 1029 mL/m(2) , P = 0.402). Significant changes were also observed in stroke volume variation (median 12.0 vs. 13.0 %, P = 0.012), cardiac index (median 4.2 vs. 3.5 mL/min/m(2) , P = 0.003), mean arterial pressure (median 77 vs. 85.5 mmHg, P = 0.006), norepinephrine dose (median 0.092 vs. 0.114 μg/kg per min, P = 0.043), and hemoglobin values (median 9.5 vs. 10.4 gm/dL, P = 0.036). RBV decreased by 7.8% (median); there was no correlation with either the volumetric measurements or the other hemodynamic parameters recorded. EVLWI reduction with dialysis reflects the removal of excess body fluid, whereas preservation of cardiac preload is indicated by ITBVI stability. Volumetric hemodynamic measurements provide additional information concerning fluid status and are thus potentially useful to guide fluid removal on hemodialysis in critically ill patients.

Use of a nutrition support protocol to increase enteral nutrition delivery in critically ill patients

BACKGROUND

Early enteral nutrition is recommended for patients in intensive care units, but nutrition provision is often hindered by a variety of unit-specific problems.

OBJECTIVES

To evaluate the impact of a nutrition support protocol on nutrition prescription and delivery in the intensive care unit.

METHODS

Nutrition-related data from 73 patients receiving mechanical ventilation who were treated in an adult medical intensive care unit before introduction of an enteral nutrition support protocol were retrospectively compared with data for 87 patients admitted after implementation of the protocol.

RESULTS

After implementation of the protocol, enteral nutrition was started significantly earlier (P = .007) and enteral feeding goals were reached significantly faster (6 vs 10 days, P < .001) than before. Prescription of enteral nutrition on the first day of invasive mechanical ventilation increased from 38% before to 54% after (P = .03) implementation of the protocol. Prescribed and delivered nutrition doses on the first 2 days of mechanical ventilation also increased significantly (P < .001) after the protocol was implemented. Nasojejunal feeding tubes were used in 52% of patients before and 56% of patients after protocol implementation P = .63). Jejunal tubes were placed earlier after the protocol was implemented than before (median 5 vs 6.5 days), and when a jejunal tube was in place, feeding goals were reached faster (median 2 vs 3 days, P = .002).

CONCLUSION

Implementing an enteral nutrition support protocol shortened the time to reach feeding goals. Jejunal feeding tubes were necessary in more than half of the patients, and with a jejunal feeding tube in place, feeding goals were reached rapidly.

Impact of Atrial Fibrillation on the Accuracy of Oscillometric Blood Pressure Monitoring

The introduction of automated oscillometric blood pressure monitors was the basis for today’s widespread use of blood pressure self-measurement. However, in atrial fibrillation, there is a controversial debate on the use of oscillometry because there is a high variability of heart rate and stroke volume. To date, the accuracy of oscillometric blood pressure monitoring in atrial fibrillation has only been investigated using auscultatory sphygmomanometry as reference method, which may be biased by arrhythmia as well. We performed a cross-sectional study in 102 patients (52 sinus rhythm, 50 atrial fibrillation) assessing the accuracy of an automated and validated oscillometric upper arm (M5 Professional, Omron) and wrist device (R5 Professional, Omron) to invasively assessed arterial pressure. Blood pressure values were calculated as the mean of 3 consecutive measurements. Systolic and diastolic blood pressure did not significantly differ in patients with sinus rhythm and atrial fibrillation, independent of the method of measurement ( P >0.05 each). The within-subject variability of the oscillometric measurements was higher in patients with atrial fibrillation compared with sinus rhythm ( P <0.01 each). The biases of systolic and diastolic blood pressure, however, did not significantly differ in presence or absence of atrial fibrillation in Bland-Altmann analysis ( P >0.05 each). In conclusion, atrial fibrillation did not significantly affect the accuracy of oscillometric measurements, if 3 repeated measurements were performed.

Native nephrectomy in transplant patients with autosomal dominant polycystic kidney disease

INTRODUCTION

This study examined the clinical indications and timing for native nephrectomy (NN), together with the associated pathological findings in transplant patients with autosomal dominant polycystic kidney disease (ADPKD) at our institute over a period of 20 years.

METHODS

A retrospective review was performed of ADPKD patients who had undergone both kidney transplantation and NN. Patients were identified from the kidney transplant database between 1988 and 2008 at Guy's and St Thomas' Hospital and the notes reviewed. All NN specimens were re-reviewed and reported according to current guidelines.

RESULTS

There were 157 kidney transplants performed for ADPKD (114 cadaveric and 43 living donor). Of these, 31 required NN (28 bilateral). The timing of NN was pre-transplant in 10 cases, at the time of the transplant in 1 case and post-transplant in 20 cases. The indications for NN were urinary tract infection (n=14, 45%), pain (n=12, 39%), tumour suspicion (n=3, 10%), haematuria (n=1, 3%) and space (n=1, 3%). Mortality in this NN series was 3%, with a 65% surgical morbidity rate. The length of hospital stay post-NN was significantly longer with open compared with laparoscopic techniques (p=0.003). There were two renal cell carcinomas (RCCs) in this series. Both patients presented with macroscopic haematuria (bilateral pT1a papillary RCCs in one case and a pT3b clear cell RCC in the other case). The incidence of RCC in this series of ADPKD transplant patients was 1.3%.

CONCLUSIONS

We have demonstrated that the majority of ADPKD patients do not require NN, with only 20% of our series undergoing this procedure. The timing of NN is variable and dictated by indication. NN was only required to make space for transplantation in one case (combined kidney and pancreas transplant). The main indications for NN were recurrent infection and pain, where NN can provide a successful outcome. Laparoscopic NN can be performed safely in patients with ADPKD. Haematuria in such patients should not be assumed to be of benign origin and requires exclusion of urinary tract malignancy as the incidence of RCC in this population is at least as common as in the general population.

Intraoperative assessment of kidney allograft perfusion by laser-assisted indocyanine green fluorescence videography

BACKGROUND

Kidney allograft function crucially depends on the quality of organ perfusion. Duplex sonography, however, frequently reveals hypoperfused segments that remained undetectable to visual inspection intraoperatively. To date, no imaging system supplementing the surgeon's experience has achieved clinical acceptance. The present work examines whether laser-assisted indocyanine green (ICG) fluorescence-videography can be used as a safe and sensitive technique for the intraoperative assessment of renal allograft perfusion.

METHODS

Intraoperative assessment of organ perfusion by laser-assisted ICG fluorescence videography (IC-VIEW) was performed in 10 consecutive de novo renal transplantations. The IC-VIEW system allows the visualization of graft perfusion by the fluorescein dye ICG that emits infrared light after exposure to laser light.

RESULTS

Perfusion measurements were successful in all 10 transplant recipients. Fluorescence videography produced brilliant, sharply contrasted images of the organs, allowing the detection of even small perfusion deficits. Remarkably, this technique detected 1 large perfusion defect that had remained imperceptible to visual inspection. Repositioning of the graft led to a homogeneous overall perfusion. There were no complications with the ICG injection or the imaging device.

CONCLUSION

Laser-assisted ICG fluorescence videography is a feasible and safe technique for the intraoperative assessment of renal allograft perfusion.

Noninvasive cardiac output determination: broadening the applicability of hemodynamic monitoring

Although cardiac output (CO) monitoring is usually only used in intensive care units (ICUs) and operating rooms, there is increasing evidence that CO should be determined and optimized as early as possible, even before admission to the ICU, in the care of hemodynamically compromised patients. A variety of different minimally or noninvasive CO determination techniques have been developed, but not all of them are suitable for early hemodynamic monitoring outside the ICU. In this review, the different available methods for CO monitoring are presented and their potential for early hemodynamic assessment is discussed.

Noninvasive cardiac output determination using applanation tonometry-derived radial artery pulse contour analysis in critically ill patients

Conventional thermodilution cardiac output (CO) monitoring is limited mainly to intensive care units and operating rooms because it requires the use of invasive techniques. To reduce the potential for complications and to broaden the applicability of hemodynamic monitoring, noninvasive methods for CO determination are being sought. Applanation tonometry allows noninvasive CO estimation through pulse contour analysis, but the method has not been evaluated in critically ill patients. We therefore performed noninvasive radial artery applanation tonometry in 49 critically ill medical intensive care unit patients and compared CO estimates to invasive CO measurements obtained using a pulmonary artery catheter or the PiCCO transpulmonary thermodilution system. One-hundred-sixteen measurements were performed, and patients were receiving vasopressor support during 78 measurements. When the data were analyzed with bias and precision statistics, a large bias of 2.03 L x min(-1) x m(-2) and a high percentage error of 85% were found between the invasive measurements and applanation tonometry-derived CO estimates, with the noninvasive CO results being significantly lower than the invasive ones (P < 0.001). There was no significant difference in bias between the patients who were receiving vasopressor support and those who were not (P = 0.874) or between patients with good and poor applanation tonometry pressure waveform signal quality (P = 0.071). Whereas a significant increase in the invasively determined CO was observed when a fluid bolus was administered (n = 7, P = 0.016), these changes were not reflected by the noninvasive method. We conclude that radial artery applanation tonometry is not suitable to determine CO in critically ill hemodynamically unstable patients.

Noninvasive pulse wave analysis for the determination of central artery stiffness

Central artery stiffness predicts cardiovascular structural damage and clinical outcome. It is controversial whether central artery stiffness can be determined by noninvasive measurements. We compared noninvasive determination of central artery stiffness obtained from applanation tonometry of the peripheral radial artery waveform with invasive measurements of the ratio of pulse-pressure-to-stroke-volume. A total of 112 invasive measurements of the ratio of pulse-pressure-to-stroke-volume and noninvasive determinations of central artery stiffness were performed in 49 patients on the intensive care unit. In 13 out of 112 attempts of noninvasive measurements (12%) radial pulse could not be obtained using applanation tonometry because of cardiac arrhythmia or radial pulse could not be detected. These 13 failing noninvasive measurements were attempted in 7 patients. In the remaining cases we found a significant correlation between noninvasively obtained central artery stiffness and invasive measurements of the ratio of pulse-pressure-to-stroke-volume (Spearman r=0.40; p<0.0001). The association between invasive and noninvasive measurements was confirmed using Bland-Altman plots. Furthermore, a norepinephrine-induced increase of arterial stiffness was detected both invasively and noninvasively. Noninvasive determination of central artery stiffness obtained from peripheral radial artery waveform should be useful in clinical practice although it cannot be performed in every patient.

Validität der Waterlow-Skala zur Dekubitusrisikoeinschätzung auf der Intensivstation: eine prospektive Untersuchung an 698 Patienten

Patienten von Intensivstationen bilden eine besondere Risikogruppe für die Entwicklung von Dekubiti. Dennoch existieren für Intensivpatienten bislang keine ausreichend spezifischen, validierten Instrumente für die Dekubitusrisikoeinschätzung. In einer prospektiven Studie an 698 Patienten einer internistischen Intensivstation der Maximalversorgung wurde untersucht, inwieweit die Waterlow-Dekubitusrisikoskala für die Anwendung auf der Intensivstation geeignet ist. Es wurden ausschließlich Patienten eingeschlossen, bei denen zum Aufnahmezeitpunkt auf die Intensivstation keine Dekubiti bestanden. Die Waterlow-Skala wurde zur Einschätzung des Dekubitusrisikos bei Aufnahme auf die Intensivstation eingesetzt, und die auf der Skala erreichte Punktzahl in Hinblick auf im Verlauf der Intensivbehandlung aufgetretene Dekubiti (121 Patienten) ausgewertet. Die Ergebnisse zeigen, dass eine ausreichende Dekubitusrisikoeinschätzung mit der Waterlow-Skala zum Aufnahmezeitpunkt auf die Intensivstation nicht möglich ist. Sensitivität und Spezifität waren mit 64.4% bzw. 48.8% bei einer vergleichsweise hohen Waterlow-Punktzahl von 30 maximiert (positive und negative Likelihood Ratio von 1.26 bzw. 0.73). Die Fläche unter der Kurve (AUC) betrug in der Receiver-Operator-Characteristic-Kurve 0.59. Durch zusätzliche Verwendung intensivmedizinischer Parameter ließ sich die Risikoeinschätzung zwar verbessern (AUC 0.69), die Entwicklung und Validierung einer spezifisch intensivmedizinischen Dekubitusrisikoskala erscheint jedoch weiterhin erforderlich, um eine zuverlässige Dekubitusrisikostratifizierung auf der Intensivstation zu ermöglichen.

Volumetric hemodynamic parameters to guide fluid removal on hemodialysis in the intensive care unit

Estimation of removable excess body fluid is difficult in critically ill patients with renal failure. Volumetric hemodynamic parameters are increasingly being used to guide fluid therapy in the intensive care unit, but their suitability to monitor fluid removal with hemodialysis in critically ill patients is not known. Changes in the extravascular lung water index (EVLWI) and intrathoracic blood volume index (ITBVI) measured with transpulmonary thermodilution immediately before and after hemodialysis were analyzed from 39 hemodialysis sessions of 9 patients consecutively treated in the medical intensive care unit of a German University Hospital. Additional hemodynamic, ventilation, and oxygenation-related parameters were recorded at the same time. Online relative blood volume (RBV) monitoring was performed in 29 sessions. Comparisons of pre and postdialysis values showed a significant reduction of the EVLWI with fluid removal (p=0.009), with only a slight nonsignificant decrease in the ITBVI. The cardiac index (CI) also decreased significantly (p=0.010), whereas blood pressure remained stable. Oxygenation improved significantly (p=0.005), and the hematocrit increased significantly with dialysis (p=0.039). There was no correlation between hematocrit changes and RBV measurements. Significant correlations existed between ITBVI and CI changes (p<0.001), but not to EVLWI reduction. The removal of excess body fluid on hemodialysis is reflected by the EVLWI reduction, whereas the preservation of cardiac preload is shown by ITBVI stability. Volumetric hemodynamic parameters could be useful to guide fluid removal with hemodialysis in the intensive care unit.

Effect of the venous catheter site on transpulmonary thermodilution measurement variables

OBJECTIVE

Transpulmonary thermodilution is increasingly used for hemodynamic monitoring of critically ill patients. Injection of a cold saline bolus in the central venous circulation is a prerequisite for transpulmonary thermodilution measurements. Superior vena cava access is typically used for injection. This access, however, is not feasible or available in all intensive care patients (e.g., in burn victims or due to contraindications for Trendelenburg position). The present study investigates whether femoral vein access can be used to obtain clinically acceptable values.

DESIGN

Open prospective trial performed between September 2005 and April 2006.

SETTINGS

Medical intensive care unit at a university hospital.

PATIENTS

Eleven critically ill patients monitored by transpulmonary thermodilution.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

A total of 44 measurements in 11 intensive care patients were performed with the Pulsion PICCO Plus device to compare cardiac output, extravascular lung water index, and global end-diastolic volume index after central venous injection of the cold saline bolus via femoral and jugular venous access. Bland-Altman analysis revealed that catheter insertion site does not relevantly influence cardiac output and extravascular lung water index. The bias between femoral and jugular injection was +0.16 L/min for cardiac output and +0.23 mL/kg for extravascular lung water index. Global end-diastolic volume index values, however, show a constant overestimation of +140.73 mL/m2 after femoral injection, as obtained by Bland-Altman analysis. This overestimation can be explained by a longer mean transit time due to a longer distance of catheter tip and right atrium for a femoral catheter.

CONCLUSIONS

Transpulmonary thermodilution measurements with a cold saline bolus via a femoral catheter provide clinically reliable cardiac output and extravascular lung water index values. Concerning global end-diastolic volume index, there is a good correlation as well, but in the interpretation of the results, an overestimation has to be taken into account.

A systematic review of hand-assisted laparoscopic live donor nephrectomy

We provide a systematic review of hand-assisted laparoscopic live donor nephrectomy (HALDN), a relatively new procedure. Medline search of HALDN between 1995 and 2002 was conducted. Published studies were scored by two independent assessors using a modified form of 11 generic questions. All questions required one of three responses: 0--criterion not reported, 1--criterion reported but inadequate, 2--criterion reported and adequate. The studies were placed according to their scores in category A (score 20-22), category B (17-19) and category C (16 or less). Higher scores indicate better quality of studies. Where possible, statistical analysis of comparative data was performed. Most reports of HALDN are expert series, some comparative and a few prospective. There was good correlation between the assessors (r = 0.91), and of the seven published series on HALDN, two fell into category B and five into category C. At present, there is only one published randomised-controlled trial of HALDN vs. open donor nephrectomy; this is the only such trial in laparoscopic urology. HALDN allows kidneys to be harvested with short operating and warm ischaemia times and fewer ureteric complications. HALDN is a relatively new and effective technique, designed to make kidney donation more attractive and minimally invasive without affecting recipient outcomes. More prospective data of this technique is needed, and wide variation in reported outcome parameters need to be standardised to allow meaningful comparison.

Renal function following pregnancy in renal transplant recipients

We set out to analyse the effect of pregnancy and hypertension in renal transplant recipients and review serum creatinine levels as a marker of graft function, before, during and after pregnancy. The study was conducted at a major tertiary referral centre in London. This was a retrospective analysis of renal transplant patients who had achieved a successful pregnancy. During the period 1967-1998, there have been 272 women of childbearing age with successful renal transplants functioning for over 1 year. Within this population there have been 66 pregnancies in 41 patients resulting in 53 births. Among the pregnancies that progressed beyond 24 weeks, preterm delivery occurred in 32 (60.4%). The mean gestation was 35.7 (range 30-41), mean birth weight was 2365 grams (range 908-3430 grams) with 47%of infants weighing <2500 grams. There were vaginal deliveries in 14 (26%), the rest delivered by caesarean section. Patients that developed hypertension in late pregnancy tended to have higher pre-pregnancy creatinine levels and a deterioration of graft function postpartum. Serum creatinine levels greater than 130 micromol/l before pregnancy predict deteriorating renal function postpartum. Kaplan-Meier life survival analysis showed that the risk of subsequent graft loss is associated with increased serum creatinine levels (130-180 micromol/l) before pregnancy. Pregnancy figures in our unit are favourable compared to those reported in the literature. Poor pre-pregnancy renal function (creatinine 130-180 micromol/l) and previous hypertension is associated with a significant risk of graft failure. Creatinine levels currently deemed as being acceptable during the pregnancy of renal transplant recipients may need to be reappraised.

The ontogeny of adhesion molecules expressed on the vascular endothelium of the developing human skin

One of the important functions of adhesion molecules is to regulate the trafficking of lymphocytes and other leucocytes between the different organs and tissues of the body. These molecules are expressed on both the endothelial cells and the leucocytes, enabling them to adhere to one another and ultimately lead to extravasation of the leucocytes from the circulation into the surrounding tissue. P and E-selectin promote 'rolling' of leucocytes along the blood vessel walls, whereas ICAM-1 and VCAM-1 mediate subsequent firm adhesion, thus committing the leucocytes to extravasation. We have investigated the expression of the above endothelial adhesion molecules in relation to the developing dermal vasculature of fetal skin using histology and immunocytochemistry. This study showed that already at 11 wk of gestation some dermal vessels expressed P-selectin and ICAM-1. However, by 18 wk these molecules were identified on a significant number of vessels, including small capillaries supplying the forming dermal pegs. In contrast, E-selectin and VCAM-1 molecules were rarely seen in all specimens examined. Our results show that even at 11 wk of gestation, the fetal skin has a mechanism in place for circulating leucocytes to extravasate and provide primitive immunosurveillance. Furthermore, the similarities between the distribution of P-selectin and ICAM-1 in the 18 wk fetal skin and in the normal adult skin were striking. These findings may shed light on our understanding of how the fetus detects and reacts to infections and may, in the future, lead to advances in the management of some intrauterine infections.