Sepsis-associated acute kidney injury in patients with chronic kidney disease: Patient characteristics, prevalence, timing, trajectory, treatment and associated outcomes.

AIM: The features and outcomes of sepsis-associated acute kidney injury (SA-AKI) may be affected by chronic kidney disease (CKD). Accordingly, we aimed to compare SA-AKI in patients with or without CKD. METHODS: Retrospective cohort study in 12 intensive care units (ICU). We studied the prevalence, patient characteristics, timing, trajectory, treatment and outcomes of SA-AKI with and without CKD. RESULTS: Of 84 240 admissions, 7255 (8.6%) involved patients with CKD. SA-AKI was more common in patients with CKD (21% vs 14%; p < .001). CKD patients were older (70 vs. 60 years; p < .001), had a higher median Charlson co-morbidity index (5 vs. 3; p < .001) and acute physiology and chronic health evaluation (APACHE) III score (78 vs. 60; p < .001) and were more likely to receive renal replacement therapy (RRT) (25% vs. 17%; p < .001). They had less complete return to baseline function at ICU discharge (48% vs. 60%; p < .001), higher major adverse kidney events at day 30 (MAKE-30) (38% vs. 27%; p < .001), and higher hospital and 90-day mortality (21% vs. 13%; p < .001, and 27% vs. 16%; p < .001, respectively). After adjustment for patient characteristics and severity of illness, however, CKD was not an independent risk factor for increased 90-day mortality (OR 0.88; 95% CI 0.76-1.02; p = .08) or MAKE-30 (OR 0.98; 95% CI 0.80-1.09; p = .4). CONCLUSION: SA-AKI is more common in patients with CKD. Such patients are older, more co-morbid, have higher disease severity, receive different ICU therapies and have different trajectories of renal recovery and greater unadjusted mortality. However, after adjustment day-90 mortality and MAKE-30 risk were not increased by CKD.

Nasogastric tube placement under sonographic observation: A comparison study of ultrasound and chest radiography in mechanically ventilated patients.

BACKGROUND: Nasogastric tube insertion in the intensive care setting is common. Placement verification is required to avoid complications of bronchotracheal misplacement that range from aspiration of infused contents to death from associated causes. The gold standard of practice is chest radiography. Ultrasound is a growing modality and is readily available in most intensive care units. OBJECTIVE: The objective of this study was to examine the diagnostic accuracy of ultrasound imaging of nasogastric tube placements by nonradiologists compared with chest radiography in mechanically ventilated patients. METHODS: This is a dual-centre prospective, single-blind study. Correct placement was captured with a hyperechoic ultrasound image of a nasogastric tube in the oesophagus and epigastrium, which was compared with chest radiography. Patient enrolment included general adult intensive care unit admissions who were mechanically ventilated and required a nasogastric tube for either the treatment or monitoring of their illness. RESULTS: A total of 25 patients were enrolled (15 men, 10 women), and their mean age was 68.1 ± 13.8 years. Outcome measures were the percentage of correctly identified nasogastric tubes in the oesophagus and epigastrium. The sensitivity of oesophagus ultrasound was 88%, and the positive predictive value was 100%. The subxiphoid sensitivity was 64%, and the positive predictive value was 100%. Comparison sensitivity and specificity of oesophagus versus subxiphoid ultrasound was 64% and 33%, respectively. There was a positive predictive value of 88% and a negative predictive value of 11%. The results showed a variance in detection sensitivity in the ultrasound scans of the oesophagus (0.88) and subxiphoid (0.64) (N = 25, p = 0.012). CONCLUSION: Nasogastric tube placement verification via ultrasound in critically ill mechanically ventilated patients conducted by nonradiologists with minimal training is associated with diagnostic accuracy. These results add to the limited evidence in the current literature; however, they should be considered with awareness that placement in the stomach in this study was detected in 64% of cases, alongside the missed captured evidence of the sonographer's ability to identify misplacement.

Procalcitonin algorithm in critically ill adults with undifferentiated infection or suspected sepsis. A randomized controlled trial.

RATIONALE: The role of procalcitonin (PCT), a widely used sepsis biomarker, in critically ill patients with sepsis is undetermined. OBJECTIVES: To investigate the effect of a low PCT cut-off on antibiotic prescription and to describe the relationships between PCT plasma concentration and sepsis severity and mortality. METHODS: This was a multicenter (11 Australian intensive care units [ICUs]), prospective, single-blind, randomized controlled trial involving 400 patients with suspected bacterial infection/sepsis and expected to receive antibiotics and stay in ICU longer than 24 hours. The primary outcome was the cumulative number of antibiotics treatment days at Day 28. MEASUREMENTS AND MAIN RESULTS: PCT was measured daily while in the ICU. A PCT algorithm, including 0.1 ng/ml cut-off, determined antibiotic cessation. Published guidelines and antimicrobial stewardship were used in all patients. Primary analysis included 196 (PCT) versus 198 standard care patients. Ninety-three patients in each group had septic shock. The overall median (interquartile range) number of antibiotic treatment days were 9 (6-21) versus 11 (6-22), P = 0.58; in patients with positive pulmonary culture, 11 (7-27) versus 15 (8-27), P = 0.33; and in patients with septic shock, 9 (6-22) versus 11 (6-24), P = 0.64; with an overall 90-day all-cause mortality of 35 (18%) versus 31 (16%), P = 0.54 in the PCT versus standard care, respectively. Using logistic regression, adjusted for age, ventilation status, and positive culture, the decline rate in log(PCT) over the first 72 hours independently predicted hospital and 90-day mortality (odds ratio [95% confidence interval], 2.76 [1.10-6.96], P = 0.03; 3.20 [1.30-7.89], P = 0.01, respectively). CONCLUSIONS: In critically ill adults with undifferentiated infections, a PCT algorithm including 0.1 ng/ml cut-off did not achieve 25% reduction in duration of antibiotic treatment. Clinical trial registered with http://www.anzctr.org.au (ACTRN12610000809033).

Interventions to improve patient admission and discharge practices in adult intensive care units: A systematic review.

OBJECTIVES: To identify and synthesise interventions and implementation strategies to optimise patient flow, addressing admission delays, discharge delays, and after-hours discharges in adult intensive care units. METHODS: This systematic review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) reporting guidelines. Five electronic databases, including CINAHL, PubMed, Emcare, Scopus, and the Cochrane Library, were searched from 2007 to 2023 to identify articles describing interventions to enhance patient flow practices in adult intensive care units. The Critical Appraisal Skills Program (CASP) tool assessed the methodological quality of the included studies. All data was synthesised using a narrative approach. SETTING: Adult intensive care units. RESULTS: Eight studies met the inclusion criteria, mainly comprising quality improvement projects (n = 3) or before-and-after studies (n = 4). Intervention types included changing workflow processes, introducing decision support tools, publishing quality indicator data, utilising outreach nursing services, and promoting multidisciplinary communication. Various implementation strategies were used, including one-on-one training, in-person knowledge transfer, digital communication, and digital data synthesis and display. Most studies (n = 6) reported a significant improvement in at least one intensive care process-related outcome, although fewer studies specifically reported improvements in admission delays (0/0), discharge delays (1/2), and after-hours discharge (2/4). Two out of six studies reported significant improvements in patient-related outcomes after implementing the intervention. CONCLUSION: Organisational-level strategies, such as protocols and alert systems, were frequently employed to improve patient flow within ICUs, while healthcare professional-level strategies to enhance communication were less commonly used. While most studies improved ICU processes, only half succeeded in significantly reducing discharge delays and/or after-hours discharges, and only a third reported improved patient outcomes, highlighting the need for more effective interventions. IMPLICATIONS FOR CLINICAL PRACTICE: The findings of this review can guide the development of evidence-based, targeted, and tailored interventions aimed at improving patient and organisational outcomes.

Epidemiology of hypophosphatemia in critical illness: A multicentre, retrospective cohort study.

INTRODUCTION: Hypophosphatemia is common in critically ill patients. We have described the epidemiology of hypophosphatemia in patients admitted to the Intensive Care Units. METHODS: A multicentre, retrospective cohort study of 12 ICUs in Queensland, Australia from January 1st, 2015, to December 31st, 2021. Exclusions included readmissions, renal replacement therapy, end-stage renal disease, and palliative intent admissions and transfers from other ICUs. Patients were classified into four groups based on the severity of the first episode of low serum phosphate (PO4): "None" (PO4: ≥0.81 mmol/L, "Mild" (PO4: ≥0.50 & <0.81 mmol/L) "Moderate" (PO4: ≥0.30 & <0.50 mmol/L) and "Severe" (PO4: <0.30 mmol/L). A mixed-effect logistic regression model, including hospital as a random effect, was developed to examine factors associated with 90-day case fatality. RESULTS: Of the 89,776 patients admitted, 68,699 patients were included in this study, with 23,485 (34.2%) having hypophosphatemia with onset mostly on Day 2 of ICU admission and correcting to normal 3 days after hypophosphatemia was identified. There was substantial variation among participating ICUs in phosphate replacement; the threshold, and the route by which it was replaced. Day-90 case fatality increased with severity of hypophosphatemia (None: 3974 (8.8%), Mild: 2306 (11%), Moderate: 377 (14%); Severe: 108 (21%) (p < 0.001)). Multivariable regression analysis showed that compared to those without hypophosphatemia, patients with moderate (odds ratio (OR) 1.24; 95% confidence intervals (CI) 1.07-1.44; p = 0.004) or severe (OR 1.49; 95% CI 1.13-1.97; p = 0.005) hypophosphatemia had increased risk of 90-day case fatality. CONCLUSION: Hypophosphatemia was common, and mostly occurred on day 2 with early correction of serum phosphate. Phosphate replacement practices were variable among ICUs. Moderate and severe hypophosphatemia was associated with increased 90-day case fatality.

Rapid uptake of adjunctive corticosteroids for critically ill adults with septic shock following publication of ADRENAL trial. A multicenter, retrospective analysis of prescribing practices in Queensland Intensive Care Units.

BACKGROUND: Septic shock is common and associated with significant morbidity and mortality. The ADRENAL trial examined the use of hydrocortisone in patients with septic shock, demonstrating no difference in patient-centred outcomes but a decrease in the time to shock resolution. The change in clinical practice related to the publication of the ADRENAL trial is currently unknown. METHODS: A retrospective cohort study examining the use of hydrocortisone in patients with septic shock was conducted in 12 intensive care units (ICUs). A segmented linear regression was performed to identify a stepwise change in hydrocortisone administration and 90-day mortality associated with the publication of the ADRENAL trial. RESULTS: We included 4,198 patients with a mean age of 58 years (standard deviation, SD17), and the median noradrenaline equivalent score (NEE) was 0.07 µg/kg/min (IQR 0.02 - 0.17). Segmented regression analysis for hydrocortisone administration identified two breakpoints, 3 months before and 6 months after publication, leading to three periods: Pre-publication, Transition and Post-publication. Compared to the pre-publication period, the Transition and Post-publication cohorts had a higher proportion of hydrocortisone administration (28% vs. 34% vs. 43%; p < 0.0001). Furthermore, after adjustment for temporal change, the transition period had a significant change in the slope of the proportion of patients receiving hydrocortisone (-0.1% per month vs. +1.4% per month; p = 0.026), whereas this was not statistically significant during the post-publication period (+0.1% per month, p = 0.66). After adjusting for confounders, the Transition and Post-publication periods were independently associated with an increase in hydrocortisone (OR 1.4, 95% CI 1.14 - 1.77; p = 0.0015 and OR 2.03; 95% CI 1.74 - 2.36; p < 0.001, respectively). Furthermore, after adjusting for confounders, when compared to the Pre-transition period, the use of hydrocortisone was associated with a statistically significant decrease in 90-day mortality (14% vs. 24% absolute difference, aHR for hydrocortisone effect -0.81; 95% CI 0.65 - 0.99; p = 0.044). CONCLUSION: Publication of the ADRENAL trial changed clinical practice in Queensland ICUs with increased prescription of hydrocortisone for patients with septic shock with an associated reduction in mortality.

Establishing critical care nursing research priorities for three Australian regional public hospitals: A mixed method priority setting study.

OBJECTIVE: To determine key priorities for critical care nursing research in three Australian regional public hospitals, representing the shared priorities of healthcare professionals and patient representatives. METHODS: A three phase priority setting study, including consensus methods (nominal group), survey, qualitative interviews and focus groups were conducted between May 2021 and March 2022. Healthcare professionals and patient representatives from critical care units in regional public hospitals in Australia participated. A patient representative contributed to research design and co-authored this paper. RESULTS: In phase one, 29 research topics were generated. In phase two, during a nominal group ranking process, the top 5 priority areas for each site were identified. In the final phase, three themes from focus groups and interviews included patient flow through intensive care, patient care through intensive care journey and intensive care patient recovery. CONCLUSION: Identifying context specific research priorities through a priority setting exercise provides insight into the topics that are important to healthcare professionals and to patients in critical care. The top research priorities for nursing research in critical care in regional Australian hospitals include patient flow, patient recovery, and evidence based patient care through the intensive care journey, such as delirium management, pain and sedation, and mobilisation. These shared priorities will be used to guide future nursing research in critical care over the next 3-5 years. IMPLICATIONS FOR CLINICAL PRACTICE: The method we used in identifying the research priorities can be used by other researchers and clinicians; close collaboration among researchers and clinicians will be beneficial for practice improvement; and how we can be reassured that our practice is evidence based is worthy of attention.

Sepsis-associated acute kidney injury in the intensive care unit: incidence, patient characteristics, timing, trajectory, treatment, and associated outcomes. A multicenter, observational study.

PURPOSE: The Acute Disease Quality Initiative (ADQI) Workgroup recently released a consensus definition of sepsis-associated acute kidney injury (SA-AKI), combining Sepsis-3 and Kidney Disease Improving Global Outcomes (KDIGO) AKI criteria. This study aims to describe the epidemiology of SA-AKI. METHODS: This is a retrospective cohort study carried out in 12 intensive care units (ICUs) from 2015 to 2021. We studied the incidence, patient characteristics, timing, trajectory, treatment, and associated outcomes of SA-AKI based on the ADQI definition. RESULTS: Out of 84,528 admissions, 13,451 met the SA-AKI criteria with its incidence peaking at 18% in 2021. SA-AKI patients were typically admitted from home via the emergency department (ED) with a median time to SA-AKI diagnosis of 1 day (interquartile range (IQR) 1-1) from ICU admission. At diagnosis, most SA-AKI patients (54%) had a stage 1 AKI, mostly due to the low urinary output (UO) criterion only (65%). Compared to diagnosis by creatinine alone, or by both UO and creatinine criteria, patients diagnosed by UO alone had lower renal replacement therapy (RRT) requirements (2.8% vs 18% vs 50%; p < 0.001), which was consistent across all stages of AKI. SA-AKI hospital mortality was 18% and SA-AKI was independently associated with increased mortality. In SA-AKI, diagnosis by low UO only, compared to creatinine alone or to both UO and creatinine criteria, carried an odds ratio of 0.34 (95% confidence interval (CI) 0.32-0.36) for mortality. CONCLUSION: SA-AKI occurs in 1 in 6 ICU patients, is diagnosed on day 1 and carries significant morbidity and mortality risk with patients mostly admitted from home via the ED. However, most SA-AKI is stage 1 and mostly due to low UO, which carries much lower risk than diagnosis by other criteria.

Esmolol for intractable ventricular arrhythmias in major amitriptyline toxicity.

A massive tricyclic overdose of 10 g of amitriptyline resulted in cardiovascular collapse with multiple episodes of ventricular tachycardia and ventricular fibrillation despite aggressive attention to current recommended therapy of sodium bicarbonate and hypertonic saline, and correction of electrolytes. Second-line antiarrhythmic therapies failed to reduce the recurrent deterioration to malignant ventricular rhythms. Progression to extracorporeal support was avoided by the use of a titrated esmolol infusion. We discuss the physiological rationale by which esmolol may prevent tachyarrhythmia and fibrillation in severe amitriptyline toxicity.

Unexpected survival after deliberate phosphine gas poisoning: An Australian experience of extracorporeal membrane oxygenation rescue in this setting.

Phosphine poisoning is responsible for hundreds of thousands of deaths per year in countries where access to this pesticide is unrestricted. Metal phosphides release phosphine gas on contact with moisture, and ingestion of these tablets most often results in death despite intensive support. A 36-year-old woman presented to a regional hospital after ingesting multiple aluminium phosphide pesticide tablets and rapidly developed severe cardiogenic shock. In this case, serendipitous access to an untested Extracorporeal Membrane Oxygenation (ECMO) service of a regional hospital effected a successful rescue and prevented the predicted death. We discuss the toxicology, management and the evidence for and against using ECMO in this acute poisoning.

Recommendations for the development and use of imaging test sets to investigate the test performance of artificial intelligence in health screening.

Rigorous evaluation of artificial intelligence (AI) systems for image classification is essential before deployment into health-care settings, such as screening programmes, so that adoption is effective and safe. A key step in the evaluation process is the external validation of diagnostic performance using a test set of images. We conducted a rapid literature review on methods to develop test sets, published from 2012 to 2020, in English. Using thematic analysis, we mapped themes and coded the principles using the Population, Intervention, and Comparator or Reference standard, Outcome, and Study design framework. A group of screening and AI experts assessed the evidence-based principles for completeness and provided further considerations. From the final 15 principles recommended here, five affect population, one intervention, two comparator, one reference standard, and one both reference standard and comparator. Finally, four are appliable to outcome and one to study design. Principles from the literature were useful to address biases from AI; however, they did not account for screening specific biases, which we now incorporate. The principles set out here should be used to support the development and use of test sets for studies that assess the accuracy of AI within screening programmes, to ensure they are fit for purpose and minimise bias.

UK National Screening Committee's approach to reviewing evidence on artificial intelligence in breast cancer screening.

Artificial intelligence (AI) could have the potential to accurately classify mammograms according to the presence or absence of radiological signs of breast cancer, replacing or supplementing human readers (radiologists). The UK National Screening Committee's assessments of the use of AI systems to examine screening mammograms continues to focus on maximising benefits and minimising harms to women screened, when deciding whether to recommend the implementation of AI into the Breast Screening Programme in the UK. Maintaining or improving programme specificity is important to minimise anxiety from false positive results. When considering cancer detection, AI test sensitivity alone is not sufficiently informative, and additional information on the spectrum of disease detected and interval cancers is crucial to better understand the benefits and harms of screening. Although large retrospective studies might provide useful evidence by directly comparing test accuracy and spectrum of disease detected between different AI systems and by population subgroup, most retrospective studies are biased due to differential verification (ie, the use of different reference standards to verify the target condition among study participants). Enriched, multiple-reader, multiple-case, test set laboratory studies are also biased due to the laboratory effect (ie, radiologists' performance in retrospective, laboratory, observer studies is substantially different to their performance in a clinical environment). Therefore, assessment of the effect of incorporating any AI system into the breast screening pathway in prospective studies is required as it will provide key evidence for the effect of the interaction of medical staff with AI, and the impact on women's outcomes.

Sodium chloride or Plasmalyte-148 evaluation in severe diabetic ketoacidosis (SCOPE-DKA): a cluster, crossover, randomized, controlled trial.

PURPOSE: To determine whether treatment with Plasmalyte-148 (PL) compared to sodium chloride 0.9% (SC) results in faster resolution of diabetic ketoacidosis (DKA) and whether the acetate in PL potentiates ketosis. METHODS: We conducted a cluster, crossover, open-label, randomized, controlled Phase 2 trial at seven hospitals in adults admitted to intensive care unit (ICU) with severe DKA with hospital randomised to PL or SC as fluid therapy. The primary outcome, DKA resolution, was defined as a change in base excess to ≥ - 3 mEq/L at 48 h. RESULTS: Ninety-three patients were enrolled with 90 patients included in the modified-intention-to-treat population (PL n = 48, SC n = 42). At 48 h, mean fluid administration was 6798 ± 4850 ml vs 6574 ± 3123 ml, median anion gap 6 mEq/L (IQR 5-7) vs 7 mEq/L (IQR 5-7) and median blood ketones 0.3 mmol/L (IQR 0.1-0.5) vs 0.3 (IQR 0.1-0.5) in the PL and SC groups. DKA resolution at 48 h occurred in 96% (PL) and 86% (SC) of patients; odds ratio 3.93 (95% CI 0.73-21.16, p = 0.111). At 24 h, DKA resolution occurred in 69% (PL) and 36% (SC) of patients; odds ratio 4.24 (95% CI 1.68-10.72, p = 0.002). The median ICU and hospital lengths of stay were 49 h (IQR 23-72) vs 55 h (IQR 41-80) and 81 h (IQR 58-137) vs 98 h (IQR 65-195) in the PL and SC groups. CONCLUSION: Plasmalyte-148, compared to sodium chloride 0.9%, may lead to faster resolution of metabolic acidosis in patients with DKA without an increase in ketosis. These findings need confirmation in a large, Phase 3 trial.

Managing cardiovascular collapse in severe flecainide overdose without recourse to extracorporeal therapy.

Flecainide overdose can rapidly result in profound cardiovascular collapse, and is associated with a relatively high mortality. A case is described where a woman with major toxicity and high serum levels was managed without recourse to invasive modalities such as cardiopulmonary bypass or extracorporeal therapies. Hypertonic sodium bicarbonate is recognized as effective therapy for hypotension and arrhythmias. More recent case reports have concentrated on the use of cardiopulmonary bypass. In this report and other reports describing successful resuscitation, the total dose of sodium bicarbonate is conspicuously higher than in reports describing extracorporeal interventions. Sodium bicarbonate should be given early in the resuscitation, and re-administered as frequently as required, targeting an alkaline pH and improved cardiac output, while accepting hypernatraemia. This case demonstrates the maxim that the correct dose of hypertonic sodium bicarbonate is 'enough'. Cardiopulmonary bypass support can be considered as a salvage therapy.

Successful treatment of cytomegalovirus associated hemophagocytic lymphohistiocytosis with the interleukin 1 inhibitor - anakinra.

Hemophagocytic lymphohistiocytosis (HLH) is a rare, frequently under-recognized condition associated with multi-organ failure and very high mortality. A 44-year-old woman was admitted with a 4-day history of fever, headache, delirium, and dyspnea. She progressed rapidly to type 1 respiratory failure and required intubation and mechanical ventilation. Laboratory tests showed pancytopenia, abnormal liver enzyme levels, elevated triglyceride level, and elevated ferritin level. Bone marrow biopsy showed features of HLH. Computed tomography scan showed bilateral consolidation. Bronchoalveolar lavage was positive for cytomegalovirus. She was treated with ganciclovir, methylprednisolone, broad spectrum antibiotics, and cytomegalovirus hyperimmunoglobulin without clinical response. Given the poor prognosis and reports of success in pediatric HLH, anakinra 100 µg subcutaneously daily was commenced. There was rapid defervescence, resolution of delirium, and improvement in gas exchange, leading to complete recovery. This case illustrates successful treatment of HLH associated with cytomegalovirus pneumonitis with the interleukin 1 inhibitor anakinra.

Mechanism for defoaming by oils and calcium soap in aqueous systems.

The effect of oils, hardness, and calcium soap on foam stability of aqueous solutions of commercial surfactants was investigated. For conditions where negligible calcium soap was formed, stability of foams made with 0.1 wt% solutions of a seven-EO alcohol ethoxylate containing dispersed drops of n-hexadecane, triolein, or mixtures of these oils with small amounts of oleic acid could be understood in terms of entry, spreading, and bridging coefficients, i.e., ESB analysis. However, foams made from solutions containing 0.01 wt% of three-EO alcohol ethoxysulfate sodium salt and the same dispersed oils were frequently more stable than expected based on ESB analysis, reflecting that repulsion due to overlap of electrical double layers in the asymmetric oil-water-air film made oil entry into the air-water interface more difficult than the theory predicts. When calcium soap was formed in situ by the reaction of fatty acids in the oil with calcium, solid soap particles were observed at the surfaces of the oil drops. The combination of oil and calcium soap produced a synergistic effect facilitating the well-known bridging instability of foam films or Plateau borders and producing a substantial defoaming effect. A possible mechanism of instability involving increases in disjoining pressure at locations where small soap particles approach the air-water interface is discussed. For both surfactants with the triolein-oleic acid mixtures, calculated entry and bridging coefficients for conditions when calcium soap formed were positive shortly after foam generation but negative at equilibrium. These results are consistent with the experimental observation that most defoaming action occurred shortly after foam generation rather than at later times.

Defoaming effect of calcium soap.

The effect of calcium oleate on foam stability was studied for aqueous solutions of two commonly used surfactants (anionic and nonionic) under alkaline conditions in the absence of oil. For the anionic surfactant, defoaming by calcium oleate appears to involve two mechanisms. One is that oleate and calcium ions are presumably incorporated into the surfactant monolayers with a resulting decrease in the maximum of the disjoining pressure curve and therefore produces less stable thin films. The other is bridging of the films by calcium oleate particles. The latter mechanism was especially important in freshly made solutions where precipitation in the aqueous phase was still occurring when the foam was generated. Foams generated after aging (hours) when precipitation was nearly complete were more stable even though solution turbidities were greater. Foams of the nonionic surfactant were less stable than those of the anionic surfactant but were also destabilized by sufficient amounts of calcium oleate and exhibited a similar aging effect. A simplified model was developed for estimating the sodium oleate concentration at which precipitation commences in solutions of the anionic surfactant containing dissolved calcium. It includes enhancement of calcium content in the electrical double layers of the surfactant micelles. Predictions of the model were in agreement with experiment.

Micronutrient supplementation in maintenance haemodialysis patients enhances activity of antioxidant enzymes.

BACKGROUND: Haemodialysis patients are exposed to high levels of oxidative stress, perhaps contributing to increased rates of cardiovascular and malignant disease. In this context, the body's defence mechanisms against oxidative insult, including activity of the antioxidant enzymes superoxide dismutase (SOD) and glutathione peroxidase (GPx), are known to be deranged. METHODS: This randomised double-blind study assessed the effects of a novel micronutrient cocktail containing physiological doses of antioxidant vitamins and trace minerals on antioxidant enzyme activity in maintenance haemodialysis. Thirty-seven patients were randomised to receive placebo or micronutrient. SOD and GPx activity was analysed at baseline and after 6 months of treatment. RESULTS: SOD levels did not change in the treatment group but fell significantly (p=0.0443) in controls, while activity of GPx remained unchanged in controls but rose significantly (p=0.0123) in treated patients. CONCLUSIONS: These results are consistent with a beneficial effect of the cocktail on antioxidant enzyme activity and may contribute to an indication for large-scale studies to assess clinical outcome measures.

Envenoming by the rough-scaled snake (Tropidechis carinatus): a series of confirmed cases.

OBJECTIVE: To describe demographic, geographical and clinical features of envenoming by the rough-scaled snake (RSS) (Tropidechis carinatus). DESIGN, SETTING AND PARTICIPANTS: Prospective cohort study of RSS snakebite victims, recruited between January 2004 and December 2008, as part of the Australian Snakebite Project. RSS envenoming cases were confirmed by snake identification and/or venom-specific enzyme immunoassay. MAIN OUTCOME MEASURES: Clinical and laboratory features of envenoming. RESULTS: There were 24 confirmed cases of RSS envenoming, nearly all occurring in coastal areas between northern New South Wales and south-eastern Queensland. Twenty-three patients had local bite-site effects and 17 had at least three non-specific systemic effects (eg, nausea, headache). All 24 had venom-induced consumption coagulopathy (VICC), and 19 had an international normalised ratio>3.0. Six had bleeding from the bite site or intravenous cannula site, 10 had blood detected on urinalysis, and one had a major intra-abdominal haemorrhage. Mild neurotoxicity developed in two patients, and one patient developed myotoxicity with generalised myalgia, myoglobinuria and a peak creatine kinase level of 59 700 IU/L. Twenty-three patients were treated with antivenom (21 with tiger snake antivenom, two with polyvalent antivenom). Free venom was undetectable in 19 of 20 blood samples taken after antivenom administration. CONCLUSION: RSS envenoming occurs predominantly in coastal areas of northern NSW and southern Queensland, and within this range, most envenoming is due to the RSS rather than tiger snakes. Clinically it is characterised by VICC, with mild neurotoxicity and myotoxicity in some cases. Tiger snake antivenom appears to be effective against RSS envenoming.