End-of-life practices in Hong Kong intensive care units: results from the Ethicus-2 study.

INTRODUCTION: The need for end-of-life care is common in intensive care units (ICUs). Although guidelines exist, little is known about actual end-of-life care practices in Hong Kong ICUs. The study aim was to provide a detailed description of these practices. METHODS: This prospective, multicentre observational sub-analysis of the Ethicus-2 study explored end-of-life practices in eight participating Hong Kong ICUs. Consecutive adult ICU patients admitted during a 6-month period with life-sustaining treatment (LST) limitation or death were included. Follow-up continued until death or 2 months from the initial decision to limit LST. RESULTS: Of 4922 screened patients, 548 (11.1%) had LST limitation (withholding or withdrawal) or died (failed cardiopulmonary resuscitation/brain death). Life-sustaining treatment limitation occurred in 455 (83.0%) patients: 353 (77.6%) had decisions to withhold LST and 102 (22.4%) had decisions to withdraw LST. Of those who died without LST limitation, 80 (86.0%) had failed cardiopulmonary resuscitation and 13 (14.0%) were declared brain dead. Discussions of LST limitation were initiated by ICU physicians in most (86.2%) cases. Shared decision-making between ICU physicians and families was the predominant model; only 6.0% of patients retained decision-making capacity. Primary medical reasons for LST limitation were unresponsiveness to maximal therapy (49.2%) and multiorgan failure (17.1%). The most important consideration for decision-making was the patient's best interest (81.5%). CONCLUSION: Life-sustaining treatment limitations are common in Hong Kong ICUs; shared decision-making between physicians and families in the patient's best interest is the predominant model. Loss of decision-making capacity is common at the end of life. Patients should be encouraged to communicate end-of-life treatment preferences to family members/surrogates, or through advance directives.

End-of-life practices in 11 German intensive care units : Results from the ETHICUS-2 study.

BACKGROUND: End-of-life care is common in German intensive care units (ICUs) but little is known about daily practice. OBJECTIVES: To study the practice of end-of-life care. METHODS: Prospectively planned, secondary analysis comprising the German subset of the worldwide Ethicus­2 Study (2015-2016) including consecutive ICU patients with limitation of life-sustaining therapy or who died. RESULTS: Among 1092 (13.7%) of 7966 patients from 11 multidisciplinary ICUs, 967 (88.6%) had treatment limitations, 92 (8.4%) died with failed CPR, and 33 (3%) with brain death. Among patients with treatment limitations, 22.3% (216/967) patients were discharged alive from the ICU. More patients had treatments withdrawn than withheld (556 [57.5%] vs. 411 [42.5%], p < 0.001). Patients with treatment limitations were older (median 73 years [interquartile range (IQR) 61-80] vs. 68 years [IQR 54-77]) and more had mental decision-making capacity (12.9 vs. 0.8%), advance directives (28.6 vs. 11.2%), and information about treatment wishes (82.7 vs 33.3%, all p < 0.001). Physicians reported discussing treatment limitations with patients with mental decision-making capacity and families (91.3 and 82.6%, respectively). Patient wishes were unknown in 41.3% of patients. The major reason for decision-making was unresponsiveness to maximal therapy (34.6%). CONCLUSIONS: Treatment limitations are common, based on information about patients' wishes and discussion between stakeholders, patients and families. However, our findings suggest that treatment preferences of nearly half the patients remain unknown which affects guidance for treatment decisions.

Surviving sepsis campaign: international guidelines for management of sepsis and septic shock: 2016

OBJECTIVE: To provide an update to "Surviving Sepsis Campaign Guidelines for Management of Sepsis and Septic Shock: 2012". DESIGN: A consensus committee of 55 international experts representing 25 international organizations was convened. Nominal groups were assembled at key international meetings (for those committee members attending the conference). A formal conflict-of-interest (COI) policy wasdeveloped at the onset of the process and enforced throughout. A stand-alone meeting was held for all panel members in December 2015. Teleconferences and electronic-based discussion among subgroupsand among the entire committee served as an integral part of the development. METHODS: The panel consisted of five sections: hemodynamics, infection, adjunctive therapies, metabolic, and ventilation. Population, intervention, comparison, and outcomes (PICO) questions were reviewed and updated as needed, and evidence profiles were generated. Each subgroup generated a list of questions, searched for best available evidence, and then followed the principles of the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system to assess the quality of evidence from high to very low, and to formulate recommendations as strong or weak, or best practice statement when applicable. RESULTS: The Surviving Sepsis Guideline panel provided 93 statements on early management and resuscitation of patients with sepsis or septic shock. Overall, 32 were strong recommendations, 39 were weak recommendations, and 18 were best-practice statements. No recommendation was provided for four questions. CONCLUSIONS: Substantial agreement exists among a large cohort of international experts regarding many strong recommendations for the best care of patients with sepsis. Although a significant number of aspects of care have relatively weak support, evidence-based recommendations regarding the acute management of sepsis and septic shock are the foundation of improved outcomes for these critically ill patients with high mortality.(AU)

The status of intensive care medicine research and a future agenda for very old patients in the ICU.

The "very old intensive care patients" (abbreviated to VOPs; greater than 80 years old) are probably the fastest expanding subgroup of all intensive care unit (ICU) patients. Up until recently most ICU physicians have been reluctant to admit these VOPs. The general consensus was that there was little survival to gain and the incremental life expectancy of ICU admission was considered too small. Several publications have questioned this belief, but others have confirmed the poor long-term mortality rates in VOPs. More appropriate triage (resource limitation enforced decisions), admission decisions based on shared decision-making and improved prediction models are also needed for this particular patient group. Here, an expert panel proposes a research agenda for VOPs for the coming years.

Surviving sepsis campaign: international guidelines for management of severe sepsis and septic shock, 2012

Objective: To provide an update to the "Surviving Sepsis Campaign Guidelines for Management of Severe Sepsis and Septic Shock," last published in 2008. Design: A consensus committee of 68 international experts representing 30 international organizations was convened. Nominal groups were assembled at key international meetings (for those committee members attending the conference). A formal conflict of interest policy was developed at the onset of the process and enforced throughout. The entire guidelines process was conducted independent of any industry funding. A stand-alone meeting was held for all subgroup heads, co- and vice-chairs, and selected individuals. Teleconferences and electronic-based discussion among subgroups and among the entire committee served as an integral part of the development. Methods: The authors were advised to follow the principles of the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system to guide assessment of quality of evidence from high (A) to very low (D) and to determine the strength of recommendations as strong (1) or weak (2). The potential drawbacks of making strong recommendations in the presence of low-quality evidence were emphasized. Recommendations were classified into three groups: (1) those directly targeting severe sepsis; (2) those targeting general care of the critically ill patient and considered high priority in severe sepsis; and (3) pediatric considerations. Results: Key recommendations and suggestions, listed by category, include: early quantitative resuscitation of the septic patient during the first 6 h after recognition (1C); blood cultures before antibiotic therapy (1C); imaging studies performed promptly to confirm a potential source of infection (UG); administration of broad-spectrum antimicrobials therapy within 1 h of the recognition of septic shock (1B) and severe sepsis without septic shock (1C) as the goal of therapy; reassessment of antimicrobial therapy daily for de-escalation, when appropriate (1B); infection source control with attention to the balance of risks and benefits of the chosen method within 12 h of diagnosis (1C); initial fluid resuscitation with crystalloid (1B) and consideration of the addition of albumin in patients who continue to require substantial amounts of crystalloid to maintain adequate mean arterial pressure (2C) and the avoidance of hetastarch formulations (1B); initial fluid challenge in patients with sepsis-induced tissue hypoperfusion and suspicion of hypovolemia to achieve a minimum of 30 mL/kg of crystalloids (more rapid administration and greater amounts of fluid may be needed in some patients (1C); fluid challenge technique continued as long as hemodynamic improvement is based on either dynamic or static variables (UG); norepinephrine as the first-choice vasopressor to maintain mean arterial pressure ≥65 mmHg (1B); epinephrine when an additional agent is needed to maintain adequate blood pressure (2B); vasopressin (0.03 U/min) can be added to norepinephrine to either raise mean arterial pressure to target or to decrease norepinephrine dose but should not be used as the initial vasopressor (UG); dopamine is not recommended except in highly selected circumstances (2C); dobutamine infusion administered or added to vasopressor in the presence of (a) myocardial dysfunction as suggested by elevated cardiac filling pressures and low cardiac output, or (b) ongoing signs of hypoperfusion despite achieving adequate intravascular volume and adequate mean arterial pressure (1C); avoiding use of intravenous hydrocortisone in adult septic shock patients if adequate fluid resuscitation and vasopressor therapy are able to restore hemodynamic stability (2C); hemoglobin target of 7­9 g/dL in the absence of tissue hypoperfusion, ischemic coronary artery disease, or acute hemorrhage (1B); low tidal volume (1A) and limitation of inspiratory plateau pressure (1B) for acute respiratory distress syndrome (ARDS); application of at least a minimal amount of positive end-expiratory pressure (PEEP) in ARDS (1B); higher rather than lower level of PEEP for patients with sepsis-induced moderate or severe ARDS (2C); recruitment maneuvers in sepsis patients with severe refractory hypoxemia due to ARDS (2C); prone positioning in sepsis-induced ARDS patients with a PaO 2/FiO 2 ratio of ≤100 mm Hg in facilities that have experience with such practices (2C); head-of-bed elevation in mechanically ventilated patients unless contraindicated (1B); a conservative fluid strategy for patients with established ARDS who do not have evidence of tissue hypoperfusion (1C); protocols for weaning and sedation (1A); minimizing use of either intermittent bolus sedation or continuous infusion sedation targeting specific titration endpoints (1B); avoidance of neuromuscular blockers if possible in the septic patient without ARDS (1C); a short course of neuromuscular blocker (no longer than 48 h) for patients with early ARDS and a PaO 2/FI O 2<150 mm Hg (2C); a protocolized approach to blood glucose management commencing insulin dosing when two consecutive blood glucose levels are >180 mg/dL, targeting an upper blood glucose ≤180 mg/dL (1A); equivalency of continuous veno-venous hemofiltration or intermittent hemodialysis (2B); prophylaxis for deep vein thrombosis (1B); use of stress ulcer prophylaxis to prevent upper gastrointestinal bleeding in patients with bleeding risk factors (1B); oral or enteral (if necessary) feedings, as tolerated, rather than either complete fasting or provision of only intravenous glucose within the first 48 h after a diagnosis of severe sepsis/septic shock (2C); and addressing goals of care, including treatment plans and end-of-life planning (as appropriate) (1B), as early as feasible, but within 72 h of intensive care unit admission (2C). Recommendations specific to pediatric severe sepsis include: therapy with face mask oxygen, high flow nasal cannula oxygen, or nasopharyngeal continuous PEEP in the presence of respiratory distress and hypoxemia (2C), use of physical examination therapeutic endpoints such as capillary refill (2C); for septic shock associated with hypovolemia, the use of crystalloids or albumin to deliver a bolus of 20 mL/kg of crystalloids (or albumin equivalent) over 5­10 min (2C); more common use of inotropes and vasodilators for low cardiac output septic shock associated with elevated systemic vascular resistance (2C); and use of hydrocortisone only in children with suspected or proven "absolute"' adrenal insufficiency (2C). Conclusions: Strong agreement existed among a large cohort of international experts regarding many level 1 recommendations for the best care of patients with severe sepsis. Although a significant number of aspects of care have relatively weak support, evidence-based recommendations regarding the acute management of sepsis and septic shock are the foundation of improved outcomes for this important group of critically ill patients.

Prospectively defined indicators to improve the safety and quality of care for critically ill patients: a report from the Task Force on Safety and Quality of the European Society of Intensive Care Medicine (ESICM).

OBJECTIVES: To define a set of indicators that could be used to improve quality in intensive care medicine. METHODOLOGY: An European Society of Intensive Care Medicine Task Force on Quality and Safety identified all commonly used key quality indicators. This international Task Force consisted of 18 experts, all with a self-proclaimed interest in the area. Through a modified Delphi process seeking greater than 90% consensual agreement from this nominal group, the indicators were then refined through a series of iterative processes. RESULTS: A total of 111 indicators of quality were initially found, and these were consolidated into 102 separate items. After five discrete rounds of debate, these indicators were reduced to a subset of nine that all had greater than 90% agreement from the nominal group. These indicators can be used to describe the structures (3), processes (2) and outcomes (4) of intensive care. Across this international group, it was much more difficult to obtain consensual agreement on the indicators describing processes of care than on the structures and outcomes. CONCLUSION: This document contains nine indicators, all of which have a high level of consensual agreement from an international Task Force, which could be used to improve quality in routine intensive care practice.

Time course of organ failure in patients with septic shock treated with hydrocortisone: results of the Corticus study.

INTRODUCTION: Corticosteroids have been proposed to decrease morbidity and mortality in patients with septic shock. An impact on morbidity should be anticipated to be earlier and more easily detected than the impact on mortality. METHODS: Prospective, randomized, double-blind, placebo-controlled study of 28-day mortality in patients with septic shock for <72 h who underwent a short high-dose ACTH test in 52 centers in 9 European countries. Patients received 11-day treatment with hydrocortisone or placebo. Organ dysfunction/failure was quantified by the use of the sequential organ failure assessment (SOFA) score. RESULTS: From March 2002 to November 2005, 499 patients were enrolled (hydrocortisone 251, placebo 248). Both groups presented a similar SOFA score at baseline (hydrocortisone 10.8 ± 3.2 vs. placebo 10.7 ± 3.1 points). There was no difference in 28-day mortality between the two treatment groups (hydrocortisone 34.3% vs. placebo 31.5%). There was a decrease in the SOFA score of hydrocortisone-treated patients from day 0 to day 7 compared to the placebo-treated patients (p = 0.0027), driven by an improvement in cardiovascular organ dysfunction/failure (p = 0.0005) and in liver failure (p < 0.0001) in the hydrocortisone-treated patients. CONCLUSION: Patients randomized to treatment with hydrocortisone demonstrated a faster decrease in total organ dysfunction/failure determined by the SOFA score, primarily driven by a faster improvement in cardiovascular organ dysfunction/failure. This organ dysfunction/failure improvement was not accompanied by a decreased mortality.

Use of early corticosteroid therapy on ICU admission in patients affected by severe pandemic (H1N1)v influenza A infection.

INTRODUCTION: Early use of corticosteroids in patients affected by pandemic (H1N1)v influenza A infection, although relatively common, remains controversial. METHODS: Prospective, observational, multicenter study from 23 June 2009 through 11 February 2010, reported in the European Society of Intensive Care Medicine (ESICM) H1N1 registry. RESULTS: Two hundred twenty patients admitted to an intensive care unit (ICU) with completed outcome data were analyzed. Invasive mechanical ventilation was used in 155 (70.5%). Sixty-seven (30.5%) of the patients died in ICU and 75 (34.1%) whilst in hospital. One hundred twenty-six (57.3%) patients received corticosteroid therapy on admission to ICU. Patients who received corticosteroids were significantly older and were more likely to have coexisting asthma, chronic obstructive pulmonary disease (COPD), and chronic steroid use. These patients receiving corticosteroids had increased likelihood of developing hospital-acquired pneumonia (HAP) [26.2% versus 13.8%, p < 0.05; odds ratio (OR) 2.2, confidence interval (CI) 1.1-4.5]. Patients who received corticosteroids had significantly higher ICU mortality than patients who did not (46.0% versus 18.1%, p < 0.01; OR 3.8, CI 2.1-7.2). Cox regression analysis adjusted for severity and potential confounding factors identified that early use of corticosteroids was not significantly associated with mortality [hazard ratio (HR) 1.3, 95% CI 0.7-2.4, p = 0.4] but was still associated with an increased rate of HAP (OR 2.2, 95% CI 1.0-4.8, p < 0.05). When only patients developing acute respiratory distress syndrome (ARDS) were analyzed, similar results were observed. CONCLUSIONS: Early use of corticosteroids in patients affected by pandemic (H1N1)v influenza A infection did not result in better outcomes and was associated with increased risk of superinfections.

H2AX phosphorylation screen of cells from radiosensitive cancer patients reveals a novel DNA double-strand break repair cellular phenotype.

BACKGROUND: About 1-5% of cancer patients suffer from significant normal tissue reactions as a result of radiotherapy (RT). It is not possible at this time to predict how most patients' normal tissues will respond to RT. DNA repair dysfunction is implicated in sensitivity to RT particularly in genes that mediate the repair of DNA double-strand breaks (DSBs). Phosphorylation of histone H2AX (phosphorylated molecules are known as gammaH2AX) occurs rapidly in response to DNA DSBs, and, among its other roles, contributes to repair protein recruitment to these damaged sites. Mammalian cell lines have also been crucial in facilitating the successful cloning of many DNA DSB repair genes; yet, very few mutant cell lines exist for non-syndromic clinical radiosensitivity (RS). METHODS: Here, we survey DNA DSB induction and repair in whole cells from RS patients, as revealed by gammaH2AX foci assays, as potential predictive markers of clinical radiation response. RESULTS: With one exception, both DNA focus induction and repair in cell lines from RS patients were comparable with controls. Using gammaH2AX foci assays, we identified a RS cancer patient cell line with a novel ionising radiation-induced DNA DSB repair defect; these data were confirmed by an independent DNA DSB repair assay. CONCLUSION: gammaH2AX focus measurement has limited scope as a pre-RT predictive assay in lymphoblast cell lines from RT patients; however, the assay can successfully identify novel DNA DSB repair-defective patient cell lines, thus potentially facilitating the discovery of novel constitutional contributions to clinical RS.

Hyperthermia and irradiation of head and neck squamous cancer cells causes migratory profile changes of tumour infiltrating lymphocytes.

PURPOSE: CD4(+)CD25(+)FoxP3(+) regulatory T-cells (Treg) are responsible for immunoevasion mechanisms induced by cancer. Specific chemokines such as CCL22 are presumed to mediate active Treg trafficking into the tumour site. In this context, the effects of irradiation and hyperthermia of tumour cells on Treg migration and the CCL22 concentration in the tumour cell supernatants after treatment were studied. Moreover, the relationship between CCL22 concentration and Treg cell migration was also examined. MATERIALS AND METHODS: Treg and CD4(+)CD25(-) T-cells were isolated from human peripheral blood. Supernatants were obtained from primary cell cultures derived from head and neck carcinoma patients. Tumour cell cultures were treated with a dose of 2 Gy and hyperthermia (41.5 degrees C) or with hyperthermia or irradiation alone. Cancer cell culture supernatants were then used for a transmigration assay. RESULTS: Treg and CD4(+)CD25(-) T-cells showed an increased transmigration towards supernatants of hyperthermia-treated tumour cells. After combined application of hyperthermia and irradiation, Treg migration was similar to control levels, but CD4(+)CD25(-) migration was still enhanced. Irradiation caused a significantly decreased Treg influx, whereas the CD4(+)CD25(-) T-cell migration was not altered after the same treatment. Changes of Treg chemotaxis could be attributed to a treatment-associated escalation of the CCL22 in the tumour cell supernatants. CONCLUSION: The combination of irradiation and hyperthermia is able to modify transmigration of tumour infiltrating lymphocytes beneficially and individually. In this in vitro system hyperthermia alone negatively impacts the immune response by selectively recruiting Treg, whereas hyperthermia with the addition of irradiation negates this effect.

Detection and monitoring of biofilm formation in water treatment systems by quartz crystal microbalance sensors.

Investigations are presented for the development and testing of a sensor for the early stage detection and monitoring of biofilm formation. The sensor is based on the well known quartz crystal microbalance technology (QCM). The QCM detectors are integrated into the water flow system and provide continuous in-situ signals. The main objectives of the research are the evaluation of optimal operation conditions and the modification of the quartz resonator surface promoting a preferred cell attachment onto the quartz sensor surface. The miniaturization degree of the mass sensitive detector modules permits the integration into industrial plants, e.g., in order to control and ensure perfect hygienic conditions. First results of the lab study using Pseudomonas putida cultures are presented and discussed.

The impact of regional culture on intensive care end of life decision making: an Israeli perspective from the ETHICUS study.

BACKGROUND: Decisions of patients, families, and health care providers about medical care at the end of life depend on many factors, including the societal culture. A pan-European study was conducted to determine the frequency and types of end of life practices in European intensive care units (ICUs), including those in Israel. Several results of the Israeli subsample were different to those of the overall sample. OBJECTIVE: The objective of this article was to explore these differences and provide a possible explanation based on the impact of culture on end of life decision making. METHOD: All adult patients admitted consecutively to three Israeli ICUs (n = 2778) who died or underwent any limitation of life saving interventions between 1 January 1999 and 30 June 2000 were studied prospectively (n = 363). These patients were compared with a similar sample taken from the larger study (ethics in European intensive care units: ETHICUS) carried out in 37 European ICUs. Patients were followed until discharge, death, or 2 months from the decision to limit therapy. End of life decisions were prospectively organised into one of five mutually exclusive categories: cardiopulmonary resuscitation (CPR), brain death, withholding treatment, withdrawing treatment, and active shortening of the dying process (SDP). The data also included patient characteristics (gender, age, ICU admission diagnosis, chronic disorders, date of hospital admission, date and time of decision to limit therapy, date of hospital discharge, date and time of death in hospital), specific therapies limited, and the method of SDP. RESULTS: The majority of patients (n = 252, 69%) had treatment withheld, none underwent SDP, 62 received CPR (17%), 31 had brain death (9%), and 18 underwent withdrawal of treatment (5%). The primary reason given for limiting treatment was that the patient was unresponsive to therapy (n = 187). End of life discussions were held with 132 families (36%), the vast majority of which revolved around withholding treatment (91% of the discussions) and the remainder concerned withdrawing treatment (n = 11, 9%). There was a statistically significant association (chi2 = 830.93, df = 12, p < 0.0001) between the type of end of life decision and region-that is, the northern region of Europe, the central region, the southern region, and Israel. CONCLUSIONS: Regional culture plays an important part in end of life decision making. Differences relating to end of life decision making exist between regions and these differences can often be attributed to cultural factors. Such cultures not only affect patients and their families but also the health care workers who make and carry out such decisions.

Holy consent--a dilemma for medical staff when maternal consent is withheld for emergency caesarean section.

A parturient (grand multipara) developed arrested labour complicated by severe fetal heart rate decelerations. Senior physicians explained the need for a caesarean section, but she chose to deliver vaginally since rabbinical blessing could not be obtained. Forcing the mother to have a cesarean section without consent is considered "civil battery." The dilemma faced by medical staff and the implications of her refusal for the treating medical staff are described.

Increased risk of bloodstream and urinary infections in intensive care unit (ICU) patients compared with patients fitting ICU admission criteria treated in regular wards.

Critically ill patients, eligible for admission into intensive care units (ICUs), are often hospitalized in other wards due to a lack of ICU beds. Differences in morbidity between patients managed in ICUs and elsewhere are unknown, specifically the morbidity related to hospital-acquired infection. Patients fitting ICU admission criteria were identified by screening five entire hospitals on four separate days. Hospital infections within a 30-day follow-up period were compared in ICU patients and in patients on other wards using Kaplan-Meier curves. Residual differences in the patients' case mix between ICUs and other wards were adjusted for utilizing multivariate Cox models. Of 13415 patients screened, 668 were critically ill. The overall infection rates (per 100 patient-days) were 1.2 for bloodstream infection (BSI) and 1.9 for urinary tract infection (UTI). The adjusted hazard ratios in ICU patients compared with patients on regular wards were 3.1 (P<0.001) for BSI and 2.5 (P<0.001) for UTI. This increased risk persisted even after adjusting for the disparity in the number of cultures sent from ICUs compared with ordinary wards. No interdepartmental differences were found in the rates of pneumonia, surgical wound infections and other infections. Minimizing the differences between characteristics of patients hospitalized in ICUs and in other wards, and controlling for the higher frequency of cultures sent from ICUs did not eliminate the increased risk of BSI and UTI associated with admission into ICUs.

The enigma of underdrainage in shunting with hydrostatic valves and possible solutions.

OBJECTIVE: Hydrostatic devices have considerable advantages compared to "conventional" differential-pressure-valves concerning overdrainage, but are thought to imply a tendency to underdrain or to clog. The aim of this study was to evaluate the ability of the hydrostatic gravitational Dual-Switch-Valve (DSV) to minimize overdrainage-related complications without increasing the danger of underdrainage. RESULTS: In a series of 202 adult patients with different etiologies treated with a ventriculo-peritoneal shunt including the hydrostatic Dual-Switch-valve (DSV), 21 cases were suspected of suffering from underdrainage. Using a new algorithm we were able to differentiate obstruction in 6 patients from functional underdrainage in 15 cases, thus we saw an indication to reimplant a DSV with a lower opening pressure in the latter. CONCLUSION: The reasons for functional underdrainage were multifold in our series, especially the intraperitoneal pressure is still a "black box". Despite the ability of the DSV to avoid clogging and to minimize overdrainage by its high-pressure-chamber, it remains difficult to determine the optimal opening pressure of the low-pressure-chamber of the DSV for ideal clinical improvement. Therefore a new hydrostatic gravitational "programmable" valve (proGAV), entitled on avoiding the disadvantages of other adjustable devices, has been developed and implanted in 16 patients with promising results.

Induction of lacI mutations in Big Blue Rat-2 cells treated with 1-(2-hydroxyethyl)-1-nitrosourea: a model system for the analysis of mutagenic potential of the hydroxyethyl adducts produced by 1,3-bis (2-chloroethyl)-1-nitrosourea.

We have investigated the genotoxic effects of 1-(2-hydroxyethyl)-1-nitrosourea (HENU). We have chosen this agent because of its demonstrated ability to produce N7-(2-hydroxyethyl) guanine (N7-HOEtG) and O(6)-(2-hydroxyethyl) 2'-deoxyguanosine (O(6)-HOEtdG); two of the DNA alkylation products produced by 1,3-bis (2-chloroethyl)-1-nitrosourea (BCNU). For these studies, we have used the Big Blue Rat-2 cell line that contains a lambda/lacI shuttle vector. Treatment of these cells with HENU produced a dose dependent increase in the levels of N7-HOEtG and O(6)-HOEtdG as quantified by HPLC with electrochemical detection. Treatment of Big Blue Rat-2 cells with either 0, 1 or 5mM HENU resulted in mutation frequencies of 7.2+/-2.2x10(-5), 45.2+/-2.9x10(-5) and 120.3+/-24.4x10(-5), respectively. Comparison of the mutation frequencies demonstrates that 1 and 5mM HENU treatments have increased the mutation frequency by 6- and 16-fold, respectively. This increase in mutation frequency was statistically significant (P<0.001). Sequence analysis of HENU-induced mutations have revealed primarily G:C-->A:T transitions (52%) and a significant number of A:T-->T:A transversions (16%). We propose that the observed G:C-->A:T transitions are produced by the DNA alkylation product O(6)-HOEtdG. These results suggest that the formation of O(6)-HOEtdG by BCNU treatment contributes to its observed mutagenic properties.