6 Restricted diet causing irreversible visual impairment in children with autistic spectrum disorder: case series and review

Though micronutrient deficiency is recognized to cause visual system dysfunction, avoidant/restrictive food intake disorder (ARFID) has been poorly described in relation to this.Review of 18 previously published similar cases highlights the importance of identifying other micronutrient deficiencies, even when vitamin A deficiency accounts for the presenting features. We present four patients with permanent visual loss as a result of highly restricted diets due to avoidant/restrictive food intake disorder (ARFID), and with autistic spectrum disorder (ASD).The four cases reported here make a total of 22 reported cases of visual impairment due to ARFID-like restricted diets in boys with ASD. The severity of ASD varied widely across the 22 cases, but all had extremely restricted diets, in some cases tolerating only one or two food items. The most avoided food groups in children with ASD and food selectivity have been reported from the USA as vegetables, fruit, dairy and protein, with the most preferred food items being bread, chicken, cereal and yoghurt. In the 22 cases reviewed or reported here, tolerated foods tended to be predominately carbohydrate based, with dry or crunchy textures and beige or pale colouring, i.e. French fries, potato waffles, potato chips (crisps), rice, white bread, bagels, biscuits or cookies.This case series and review highlights the need for heightened vigilance for visual problems in individuals with ASD-related ARFID and early and complete assessment of micronutrient deficiency.

OX40 and 4-1BB delineate distinct immune profiles in sarcoma

Systemic relapse after radiotherapy and surgery is the major cause of disease-related mortality in sarcoma patients. Combining radiotherapy and immunotherapy is under investigation as a means to improve response rates. However, the immune contexture of sarcoma is understudied. Here, we use a retrospective cohort of sarcoma patients, treated with neoadjuvant radiotherapy, and TCGA data. We explore therapeutic targets of relevance to sarcoma, using genomics and multispectral immunohistochemistry to provide insights into the tumor immune microenvironment across sarcoma subtypes. Differential gene expression between radioresponsive myxoid liposarcoma (MLPS) and more radioresistant undifferentiated pleomorphic sarcoma (UPS) indicated UPS contained higher transcript levels of a number of immunotherapy targets (CD73/NT5E, CD39/ENTPD1, CD25/IL2RA, and 4-1BB/TNFRSF9). We focused on 4-1BB/TNFRSF9 and other costimulatory molecules. In TCGA data, 4-1BB correlated to an inflamed and exhausted phenotype. OX40/TNFRSF4 and 4-1BB/TNFRSF9 were highly expressed in sarcoma subtypes versus other cancers. Despite OX40 and 4-1BB being described as Treg markers, we identified that they delineate distinct tumor immune profiles. This was true for sarcoma and other cancers. While only a limited number of samples could be analyzed, spatial analysis of OX40 expression identified two diverse phenotypes of OX40+ Tregs, one associated with and one independent of tertiary lymphoid structures (TLSs). Patient stratification is of intense interest for immunotherapies. We provide data supporting the viewpoint that a cohort of sarcoma patients, appropriately selected, are promising candidates for immunotherapies. Spatial profiling of OX40+ Tregs, in relation to TLSs, could be an additional metric to improve future patient stratification.

P103 Impact of the COVID-19 pandemic on the sleep of patients of a multidisciplinary sleep clinic

Introduction

This study aimed to assess the impact of the COVID-19 pandemic on the sleep of adult patients of a multidisciplinary sleep clinic.

Methods

Patients were invited to complete online surveys: Survey 1 in October 2020 (increased COVID-19 restrictions) followed by Survey 2 in February 2021 (after easing of restrictions for a COVIDSafe summer).

Results

Of the 746 patients invited to participate, 73 completed and 8 partially returned Survey 1 (mean age 50.1 years, range 21–83 years, 58% female). Subsequently, 46 completed and 5 partially answered Survey 2. In Survey 1, 22/74 (29.7%) reported reduced sleep quantity and 31/75 (41.3%) indicated worse sleep quality compared with prior to the pandemic. In Survey 2, 33/46 (71.7%) described unchanged sleep quantity whilst 5/46 (10.9%) reported increased sleep quantity since easing COVID-19 restrictions. 36/46 (78.3%) indicated unchanged sleep quality whereas 5/46 (10.9%) described improved sleep quality since easing restrictions. However, 9/46 (19.6%) reported that their sleep remained worse compared with pre-pandemic. For patients who completed both surveys, there was no significant change in Insomnia Severity Index scores (Survey 1 mean 13.6, Survey 2 mean 12.9, mean difference -0.67 [95%CI -2.02, 0.68], p=0.32) or PROMIS Sleep-Related Impairment 8a T-scores (Survey 1 mean 59.0, Survey 2 mean 59.5, mean difference 0.44 [95%CI -1.55, 2.42], p=0.66).

Discussion

The COVID-19 pandemic has negatively affected the sleep of 44% of patients. Following easing of restrictions, symptoms of insomnia and sleep-related impairment did not change significantly, and 19.6% reported that their sleep was not back to their pre-pandemic baseline.

P057 Virus aerosol propagation by CPAP is proportional to mask leak and can be prevented by use of a hood and air filtration system

Introduction

Nosocomial transmission of SARS-CoV-2 has caused significant morbidity/mortality in the COVID-19 pandemic. Because patients auto-emit aerosols containing viable virus, these aerosols can be further propagated when patients undergo certain treatments including continuous positive airway pressure (PAP) therapy. This study aimed to assess the degree of viable virus propagated from mask leak in a PAP circuit.

Methods

Bacteriophage PhiX174 (108copies/mL) was nebulised into a custom PAP circuit. Mask leak was systematically varied to 0, 7, 21, 28 and 42 L/min at the mask interface. Plates containing Escherichia coli assessed the degree of viable virus settling on surfaces around the room. In order to contain virus spread a ventilated headboard and high efficiency particulate air (HEPA) filter was tested.

Results

Increasing mask leak was associated with virus contamination in a dose response manner (χ2= 58.24, df=4, p<0.001). Clinically relevant levels of leak (≥21 L/min) were associated with virus counts equivalent to using PAP with a standard vented mask. Viable viruses were recorded on all plates (up to 3.86m from source). A plastic hood with HEPA filtration significantly reduced viable viruses on all plates. HEPA exchange rates of 170 and 470m3/hr eradicated all evidence of virus contamination.

Discussion

Mask leak from PAP circuits may be a major source of environmental contamination and nosocomial spread of infectious respiratory diseases. Subclinical levels of leak should be treated as an infectious risk. Cheap and low-cost patient hoods with HEPA filtration are an effective countermeasure.

Upgraded flowing liquid lithium limiter for improving Li coverage uniformity and erosion resistance in EAST device

We report on design and technology improvements for a flowing liquid lithium (FLiLi) limiter inserted into auxiliary heated discharges in the experimental advanced superconducting tokamak device. In order to enhance Li coverage uniformity and erosion resistance, a new liquid Li distributor with homogenous channels was implemented. In addition, two independent electromagnetic pumps and a new horizontal capillary structure contributed to an improvement in the observed Li flow uniformity (from 30% in the previous FLiLi design to >80% in this FLiLi design). To improve limiter surface erosion resistance, hot isostatic press technology was applied, which improved the thermal contact between thin stainless steel protective layers covering the Cu heat sink. The thickness of the stainless steel layer was increased from 0.1 mm to 0.5 mm, which also helped macroscopic erosion resilience. Despite the high auxiliary heating power up to 4.5 MW, no Li bursts were recorded from FLiLi, underscoring the improved performance of this new design.

Refractive index determination by coherence scanning interferometry

Coherence scanning interferometry is established as a powerful noncontact, three-dimensional, metrology technique used to determine accurate surface roughness and topography measurements with subnanometer precision. The helical complex field (HCF) function is a topographically defined helix modulated by the electrical field reflectance, originally developed for the measurement of thin films. An approach to extend the capability of the HCF function to determine the spectral refractive index of a substrate or absorbing film has recently been proposed. In this paper, we confirm this new capability, demonstrating it on surfaces of silicon, gold, and a gold/palladium alloy using silica and zirconia oxide thin films. These refractive index dispersion measurements show good agreement with those obtained by spectroscopic ellipsometry.

Sleep difficulty mediates effects of vasomotor symptoms on mood in younger breast cancer survivors

OBJECTIVE

Treatment-induced early menopause occurs in > 80% of premenopausal women diagnosed with breast cancer. This study explored the relationship between vasomotor symptoms (VMS), sleep and mood in women aged 40-51 years with non-metastatic breast cancer.

METHODS

Cross-sectional study using validated questionnaires (Greene Climacteric scale and Hospital Anxiety and Depression Scale, HADS). Women (n = 114) were recruited from the community and hospital outpatient clinics. Frequency determination and structural equation modeling (SEMod) were used to examine the relationship between the latent variables: VMS, anxiety, and depression, and the indicator variable: difficulty sleeping.

RESULTS

Participants' mean age was 47 years and 94% became menopausal after breast cancer diagnosis. Difficulty sleeping was reported by 82% of women with 46% reporting (Likert scale) 'quite a bit/extremely'. Most women reported night sweats (77% of women: 47% reporting 'quite a bit/extremely') and hot flushes (84% of women: 50% reporting 'quite a bit/extremely'). HADS scores indicated clinically relevant depression and anxiety in 98% and 99% of women, respectively. SEMod revealed that VMS contributed to difficulty sleeping (standardized coefficient = 0.54; p < 0.001) and difficulty sleeping mediated the relationship between VMS and anxiety (standardized coefficient = 0.34; p = 0.03). However, difficulty sleeping did not have a significant direct impact on depression (standardized coefficient = -0.03; p = 0.8), although anxiety was a strong predictor of depression (standardized coefficient = 0.83; p = 0.015).

CONCLUSIONS

VMS, sleep and mood disturbance are commonly experienced by younger women with breast cancer. Using SEMod, we demonstrate for the first time that VMS may directly influence sleep in these women. VMS may have an indirect effect on mood, partly mediated by sleep difficulty.

Oncolytic Vaccinia virus and radiotherapy in head and neck cancer

OBJECTIVE

Oncolytic forms of attenuated Vaccinia virus are now in clinical development, assessing the compatibility of this novel treatment with radiotherapy may reveal exploitable synergistic relationships.

MATERIALS AND METHODS

In vitro analyses of cell killing, cell cycle effects and caspase activation were carried out on HN3, HN5, CAL27, Detroit, SIHN5B, and PJ41 cells. In vivo studies of the virus and X-radiation were performed on H&N xenografts in CD1 nude mice.

RESULTS

Cell killing in vitro was demonstrated to be dose- and time-dependent. Infection causes an increase in S-phase and sub-G1 cells. A dose dependent increase in active caspase-3 indicated induction of apoptosis. Xenografts injected with Vaccinia stabilised and frequently completely regressed. Combination with radiation generated additional cell death, induction of caspase activity and in vivo further improved long term regression rates.

CONCLUSIONS

These data support continued exploration of this therapy combination and indicates potential for clinical trials in head and neck cancer.

Synergistic cytotoxicity of oncolytic reovirus in combination with cisplatin-paclitaxel doublet chemotherapy

Oncolytic reovirus is currently under active investigation in a range of tumour types. Early phase studies have shown that this agent has modest monotherapy efficacy and its future development is likely to focus on combination regimens with cytotoxic chemotherapy. Indeed, phase I/II clinical trials have confirmed that reovirus can be safely combined with cytotoxic drugs, including a platin-taxane doublet regimen, which is currently being tested in a phase III clinical trial in patients with relapsed/metastatic head and neck cancer. Therefore, we have tested this triple (reovirus, cisplatin, paclitaxel) combination therapy in a panel of four head and neck cancer cell lines. Using the combination index (CI) method, the triple therapy demonstrated synergistic cytotoxicity in vitro in both malignant and non-malignant cell lines. In head and neck cancer cell lines, this was associated with enhanced caspase 3 and 7 cleavage, but no increase in viral replication. In vitro analyses confirmed colocalisation of markers of reovirus infection and caspase 3. Triple therapy was significantly more effective than reovirus or cisplatin-paclitaxel in athymic nude mice. These data suggest that the combination of reovirus plus platin-taxane doublet chemotherapy has significant activity in head and neck cancer and underpin the current phase III study in this indication.

The Importance of Informed Consent in Patients with Wet Age-related Macular Degeneration considering Intravitreal Anti-vascular Endothelial Growth Factor Treatments

Retinal pigment epithelial (RPE) tears are now a documented potential complication following the intravitreal injection of anti-vascular endothelial growth factor (VEGF) treatments for neovascular age-related macular degeneration. Patients are often not well consented regarding this risk and thus we retrospectively analyzed the data from all of our patients undergoing this treatment over a six month period. Our findings highlighted the fact that the three patients (out of thirty) who had developed this RPE tear complication were initially all diagnosed with a pigment epithelial detachment (which is a type of macular degeneration in question). Therefore, we have adjusted our informed consent procedure such that all patients with “wet” macular degeneration and especially those with pigment epithelial detachments are now fully consented regarding the risks of the intravitreal treatment, which could potentially damage their vision further.

Coloured filters and reading accuracy, comprehension and rate: a placebo-controlled study

Literature suggests that visuoperceptual deficits not normally assessed by eye examinations may be responsible for certain reading disabilities. Previous studies indicate that the use of nonoptical coloured filters may reduce these deficits and improve reading performance. Present research involved 49 participants with visuo-perceptual reading disabilities. Participants were divided into a control group who received no intervention, a placebo group who received filters in a colour complementary to the individual's optimal colour, and an experimental group who received specifically matched coloured filters. At posttest the experimental group reported statistically significantly fewer visual discomfort symptoms. The remainder of the results were, however, inconsistent. Some potential explanations are explored.

Enhanced energy confinement and performance in a low-recycling tokamak

Extensive lithium wall coatings and liquid lithium plasma-limiting surfaces reduce recycling, with dramatic improvements in Ohmic plasma discharges in the Current Drive Experiment-Upgrade. Global energy confinement times increase by up to 6 times. These results exceed confinement scalings such as ITER98P(y,1) by 2-3 times, and represent the largest increase in energy confinement ever observed for an Ohmic tokamak plasma. Measurements of Dalpha emission indicate that global recycling coefficients decrease to approximately 0.3, the lowest documented for a magnetically confined hydrogen plasma.

Acute Effects of Continuous Positive Airway Pressure on Cardiac Sympathetic Tone in Congestive Heart Failure

Background —Depressed ventricular performance and neurohormonal activation are key pathophysiological features of congestive heart failure (CHF). Although angiotensin-converting enzyme inhibitors and β-adrenoceptor blockers exert beneficial effects in CHF, mortality remains unacceptably high, and the development of further therapeutic approaches is warranted. Recent data suggest that continuous positive airway pressure (CPAP) may be of benefit in the treatment of CHF, although the mechanism for this action is incompletely understood.

Methods and Results —In the present study, we examined the effect of short-term CPAP (10 cm H 2 O for 10 minutes) on hemodynamics (Swan Ganz catheter) and total systemic and cardiac sympathetic activity (norepinephrine spillover method) in 14 CHF patients in New York Heart Association class III. The application of CPAP was associated with a fall in cardiac output (4.8±0.3 to 4.4±0.2 L/min; P <0.05) and a significant reduction in cardiac norepinephrine spillover (370±58 to 299±55 pmol/min; P <0.05), although total systemic norepinephrine spillover was unchanged.

Conclusion —The short-term application of CPAP results in an inhibition of cardiac sympathetic nervous activity. Further investigation into the potential value of long-term CPAP in CHF patients is warranted.

"Glaucoma affecting each crystalline lens": a long-lost manuscript by Dr. William Mackenzie

Dr. William Mackenzie was one of the great pioneers of British ophthalmology in the 19th century. We present a newly-discovered manuscript in which Mackenzie described how he performed surgery for bilateral nuclear sclerosis of the lens, in 1842-1843. This case became the focus for a discussion of the nature of "cataract" and "glaucoma" in the fourth edition of Mackenzie's great work, A practical treatise on diseases of the eye. Mackenzie is generally remembered as a great compiler of knowledge, but the text Mackenzie built around this case shows him pursuing original arguments based on his own observation. This case report gives us a vignette of Mackenzie that illustrates aspects of Mackenzie's character and achievements in an intimate way, and it dramatizes in a lively manner how some of the most fundamental concepts in ophthalmology evolved.

Effects of continuous positive airway pressure on lung function in patients with chronic obstructive pulmonary disease and sleep disordered breathing

OBJECTIVE

Sleep disordered breathing (SDB), namely hypoventilation and obstructive sleep apnoea, occur in about 50% of patients with severe chronic obstructive pulmonary disease (COPD). Previous studies that have investigated the reversal of SDB in such patients with nasally applied intermittent positive airway pressure have reported a fall in PaCO2 but little change in airflow obstruction. We reasoned that the lack of improvement in airflow obstruction may be due to insufficient expiratory pressure. Accordingly, we sought to determine the effects of chronic nasal continuous positive airway pressure (CPAP), at highest tolerable levels, upon blood gases and airflow obstruction in patients with severe COPD and SDB.

METHODOLOGY

Fourteen patients were studied, ten of whom were able to tolerate CPAP (10.2 +/- 0.9 cmH2O) for at least 3 months.

RESULTS

Within the CPAP compliant group, there was a fall in PaCO2 (58.0 +/- 3.5 to 48.0 +/- 0.9 mmHg, P = 0.015) associated with a rise in PaO2 (54.8 +/- 3.8 to 63.2 +/- 1.8 mmHg, P = 0.015) and forced expiratory volume in 1 s (0.95 +/- 0.13 to 1.10 +/- 0.13 L, P < 0.005). Concurrent with these improvements was a substantial fall in hospitalization rates (from 3.85 to 0.73 admissions per annum).

CONCLUSION

Improvements in gas exchange, airflow obstruction and hospitalization rates were observed in patients with COPD and SDB treated with nasal CPAP during sleep.

Substitution of alanine543 with a threonine residue at the carboxy terminal end of the beta-chain is associated with thermolabile hexosaminidase B in a Jewish family of Oriental ancestry

Thermolabile forms of the lysosomal enzyme beta-hexosaminidase B (Hex B), likely to result from different genetic defects, have been described. Ten individuals in five generations of a family of Oriental Jewish ancestry were identified biochemically as carriers of a thermolabile Hex B form. The beta-chain thermolability was found to be associated with the presence of a G --> A transition at nucleotide 1627 of the HEX B gene causing the substitution of Ala543 with a threonine. Oriental Jew whose Hex B was heat labile. Since thermolabile Hex B has been shown to occur more frequently among Jews of Oriental origin, the Ala543 --> Thr mutation may be the common mutation associated with beta-chain thermolability in this ethnic group.

Carbon dioxide volume and intra-abdominal pressure determination before the creation of a pneumoperitoneum

Laparoscopic surgery generally is regarded as a safe procedure when a preset pressure is used in the carbon dioxide insufflator. However, a fixed pressure setting is not appropriate when insufflating a very large or a very small abdomen. Presently, extrapolation from the commonly used 15 mm Hg to an appropriate and safe pressure cannot be easily determined except by a crude trial and error method. We developed an anthropometric formula to calculate the total abdominal cavity capacity and the corresponding pressure necessary to obtain safe pneumoperitoneum. This anthropometric formula calculates the total abdominal capacity by measuring one diameter from the symphysis pubis to the xyphoid bone, a second diameter as half the initial measurement, and a third diameter by dividing the waist measurement (minus an estimated percentage of body fat) and dividing that product by pi. The product of the three diameters is then multiplied by a constant (K = 0.5). We studied prospectively 20 patients whose indications for laparoscopic surgery necessitated creation of a pneumoperitoneum. The patients were divided into two groups: group A (n = 10), patients who were observed with the intra-abdominal pressure fixed at 15 mm Hg while recording the amount of distension produced in the abdominal cavity during creation of the pneumoperitoneum; and group B (n = 10) in whom pneumoperitoneum was obtained based on the initial volume of carbon dioxide-insufflation previously calculated using our formula. Based on our observations, we conclude that this anthropometric formula can be used successfully in predicting a safe level of insufflation in relation to the patient's size.

Evidence that cell surface beta 1,4-galactosyltransferase spontaneously galactosylates an underlying laminin substrate during fibroblast migration

beta 1,4-Galactosyltransferase is unusual among the glycosyltransferases in that a subpopulation exists on the cell surface in addition to its traditional biosynthetic location within the Golgi complex. On the cell surface, galactosyltransferase is expressed in spatially restricted, cell type-specific domains, where it functions as a receptor for extracellular oligosaccharide ligands during selected cellular interactions. For example, galactosyltransferase is found on the leading and trailing edges of migrating cells, where it facilitates lamellipodia formation and cell spreading by binding to specific N-linked oligosaccharides within laminin. Although the ability of galactosyltransferase to serve as a laminin receptor is well documented, it is unclear whether it functions solely in a lectin-like capacity to bind laminin glycoside ligands or uses its intrinsic catalytic activity to release itself from and modify its oligosaccharide substrate. In this study, we determined whether cell surface galactosyltransferase spontaneously galactosylates laminin matrices during cell migration using endogenous galactose donors. Cells were prelabeled with [3H]galactose, washed, and transferred in small clusters onto laminin matrices. The prelabeled cells migrated out from the cell cluster, during which time they deposited covalently bound [3H]galactose residues onto the laminin matrix. The degree of galactosylation was both laminin- and time-dependent and required actively migrating, intact cells. The radioactivity released from the 3H-galactosylated laminin by acid hydrolysis comigrated with authentic galactose standards on paper chromatography. In parallel assays, there was no radioactivity deposited on laminin matrices when cells were prelabeled with [3H]fucose or [3H]leucine. Furthermore, [3H]galactosylation was dependent upon galactosyltransferase-mediated cell migration, since prelabeled cells did not deposit [3H]galactose when migrating on fibronectin, upon which migration is integrin-dependent and galactosyltransferase-independent. These results raise the possibility that galactosyltransferase functions catalytically during cell migration, either to dissociate from its oligosaccharide ligand and/or to modify the extracellular matrix.

A comparison of conventional dialytic therapy and acute continuous hemodiafiltration in the management of acute renal failure in the critically ill

OBJECTIVE

To compare and contrast the clinical outcomes in critically ill patients with acute renal failure managed with either acute continuous hemodiafiltration or conventional dialytic therapies.

DESIGN

Retrospective review of the medical records of 167 consecutive cases of acute renal failure treated at a single center (July 1982-July 1991). Scoring for illness severity (APACHE II, number of failing organs) and assessment of outcome in terms of biochemical control of azotemia, ARF therapy-related morbidity, and overall morbidity and mortality.

SETTING

Tertiary institution.

PATIENTS

167 consecutive critically ill patients with multiorgan failure and acute renal failure.

MEASUREMENTS AND MAIN RESULTS

84 patients received conventional dialytic therapy (CDT) (1982-1988) and 83 acute continuous hemodiafiltration (ACHD) (1988-1991). The etiology of ARF and illness severity indices were similar in both groups (organ failure scores: CDT 3.9 vs. ACHD 4.1; NS). All patients were critically ill, with more severely ill patients within the ACHD groups (mean APACHE II score: CDT 25.8 vs. ACHD 28.1; p < .01). There were no significant differences in pretreatment serum creatinine, glucose, bicarbonate and phosphate, white cell and platelet counts, incidence of disseminated intravascular coagulation, prevalence of sepsis, or evidence of pulmonary and/or peripheral edema. Overall survival was 29.8% for the CDT groups and 41% for the ACHD group (NS). When patients were stratified by severity of illness, survival in those with 2 to 4 failing organs was significantly greater in the ACHD group (CDT 31.1% vs. ACHD 53.8%; p < .025). Similarly, overall survival in patients with intermediate APACHE II scores (24 to 29) was significantly better in those treated with ACHD (CDT 12.5% vs. ACHD 46.4%; p < .025). During the course of ARF, in comparison to CDT, ACHD was associated with greater overall reductions in serum creatinine, and in phosphate and plasma urea, and an increased net nutritional intake.

CONCLUSIONS

ACHD provided biochemical and outcome indicator advantages over conventional dialytic therapy. In patients with 2 to 4 failing organs or an intermediate APACHE II score (24 to 29) a significant survival advantage was demonstrated for ACHD over CDT. Although this study is a retrospective analysis, with all the inherent limitations of such studies, it suggests that ACHD is the treatment of choice for ARF in the critically ill, with maximum benefits seen in those with 2 to 4 failing organs and/or intermediate APACHE II scores.

Acute renal failure in critical illness. Conventional dialysis versus acute continuous hemodiafiltration

The dialytic therapy of choice in critically ill patients with acute renal failure (ARF) is a matter of controversy. The clinical outcome of such patients managed with either conventional dialytic therapy (CDT) or acute continuous hemodiafiltration (ACHD) was compared through retrospective review of medical records from the intensive care unit of a tertiary institution. Records from 167 critically ill patients with ARF consecutively treated in the same intensive care unit were reviewed. Eighty-four patients with ARF treated by CDT were compared to 83 treated with ACHD. The etiology of ARF and the degree of illness severity were similar in both groups (failing organs: CDT 3.9 vs. ACHD 4.1; mean APACHE II score: CDT 25.8 vs. ACHD 28.1). Overall survival was 29.8% for the CDT patients and 41% for the ACHD group (NS). In those with two to four failing organs, survival was greater in the ACHD group (53.8% vs. 31.1%; p < 0.025). This was also true for patients with an intermediate APACHE II score (24-29) who demonstrated better survival when treated by ACHD (46.4% vs. 12.5%; p < 0.025). Acute continuous hemodiafiltration was associated with better control of azotemia and hyperphosphatemia and increased nutritional intake. This retrospective study suggests that ACHD may offer clinically significant advantages over CDT, particularly in patients with an intermediate degree of critical illness severity.