Bioimpedance-measured volume overload predicts longer duration of mechanical ventilation in intensive care unit patients.

PURPOSE: Bioelectrical impedance analysis (BIA) is a technology that provides a rapid, non-invasive measurement of volume in body compartments and may aid the physician in the assessment of volume status. We sought to investigate the effect of BIA-measured volume status on duration of mechanical ventilation, 28-day mortality, and acute kidney injury requiring renal replacement therapy in a population of medical/surgical patients admitted to the intensive care unit (ICU). METHODS: Prospective observational study of adult patients who required mechanical ventilation within 24 hr of admission to ICU. Bioelectrical impedance analysis measured extracellular water (ECW) and total body water (TBW) and these measurements were recorded on days 1, 3, 5, and 7. RESULTS: A total of 36 patients were enrolled. Mean (standard deviation) age was 61.8 (21.3) years and 31% of patients were female. The majority were admitted from the emergency department or operating room. The most common diagnosis was sepsis. At 28 days, eight patients (22%) had died. There was no association between ECW/TBW ratio at day 1 and 28-day mortality (odds ratio, 1.2; 95% confidence interval [CI], 0.6 to 2.3) after adjusting for age, sex, and Acute Physiology and Chronic Health Evaluation II score. The median [interquartile range] number of ventilator days was 5 [2.5-7.5]. On day 1, for each 1% increase in the ECW/TBW ratio, there was a 1.2-fold increase in ventilator days (95% CI, 1.003 to 1.4; P = 0.05). It is notable that 20% of eligible patients could not be enrolled because medical equipment interfered with correct electrode placement. CONCLUSION: Bioimpedance-measured ECW/TBW on day 1 of admission to the ICU is associated with time on the ventilator. While this technology may be a useful adjunct to the clinical assessment of volume status, there are technical barriers to its routine use in a general ICU population.

Urinary NGAL levels before and after coronary angiography: a complex story.

BACKGROUND: We describe urinary neutrophil gelatinase-associated lipocalin (uNGAL) values in association with clinical characteristics and urinary parameters in adults undergoing coronary angiography. METHODS: This is an observational study of consecutive patients who underwent elective coronary angiography during a 4-month period in a large urban tertiary care hospital. RESULTS: One hundred and thirteen patients were enrolled, and 100 had sufficient data to be included in the analyses. A large range of preprocedural uNGAL levels were observed (range 1-269 ng/mg Cr). Median preprocedural uNGAL was 8 ng/mg Cr. Age (P = 0.009), serum creatinine (P = 0.077) and albumin excretion (P = 0.009) were significant predictors of baseline uNGAL. Half the cohort demonstrated an increase and half a decrease in the absolute values of uNGAL after angiography, irrespective of preprocedural levels. CONCLUSIONS: We observed variable, but relatively low absolute levels of uNGAL prior to angiography in this 'cardiac' cohort. Only age, serum creatinine and albumin excretion could explain some of this variability. When designing studies of at-risk individuals where uNGAL may be used as a marker for acute kidney injury, this variability should be taken into account.

Focal segmental glomerulosclerosis in mild IgA nephropathy: a clinical-pathologic study.

BACKGROUND: The significance of focal segmental glomerulosclerosis (FSGS) in mild IgA nephropathy is uncertain. METHODS: All consecutive renal biopsies performed between 1996 and 2005 in adults with a diagnosis of mild IgA nephropathy (Lee Grade 1 or 2) at St Paul's Hospital, Vancouver, Canada, were reviewed. RESULTS: Seventy-five patients were included, 26 (35%) with IgA nephropathy and FSGS (FSGS+ group) and 49 (65%) with IgA nephropathy without FSGS (FSGS- group). The mean follow-up was 3 years. At the time of renal biopsy the FSGS+ group had a lower eGFR (60 versus 73 mL/min, P = 0.02), lower serum albumin (38 versus 41 g/L, P = 0.02), higher mean arterial pressure (103 versus 97 mmHg, P = 0.03) and greater protein excretion (3.0 versus 1.3 g/day, P < 0.01) than the FSGS- group. On histology, the FSGS+ group had a higher percentage of obsolete glomeruli (23.4% versus 12.7%, P < 0.01), and 31% of FSGS+ biopsies had >or=25% tubular atrophy/interstitial fibrosis while this was not observed in the FSGS- group (P < 0.01). The primary outcome measure, DeltaGFR, was -2.56 mL/ min/year in the FSGS+ group and +1.14 mL/min/year in the FSGS- group, difference: 3.70 mL/min/year (P = 0.03) (univariate). In the multivariate model, the FSGS+ group declined at 0.19 mL/min/year (-14.16, 13.78) and the FSGS- group improved at 2.85 mL/min/year (-11.64, 17.34), difference 3.04 mL/min/year, P = 0.18. CONCLUSIONS: Our study suggests that the focal segmental glomerulosclerosis lesion and associated clinical and pathologic findings in patients with mild IgA nephropathy are associated with a worse renal outcome.

Renal artery reconstruction and kidney autotransplantation for Takayasu arteritis-induced renal artery stenosis.

A young woman with Takayasu arteritis and complex renal artery stenosis in a solitary functional kidney underwent an ex vivo revascularization with autologous saphenous vein graft and renal autotransplantation. Before surgery, she had resistant hypertension and recurrent episodes of acute kidney injury. Two years later, her blood pressure is 123/77 mm Hg, and there have been no acute kidney injury episodes. Computed tomography scan demonstrates no abnormal thickening of the graft despite proximal progression of disease to involve the superior mesenteric artery. As Takayasu arteritis is a progressive disease, use of autologous vein graft, which is unlikely to become involved, is of paramount importance.

Acute hemodialysis in a young man with severe symptomatic hyponatremia and kidney injury.

A 35-year-old man presented with severe hypo-osmolar hyponatremia (serum sodium 99 mmol/L), profound nonoliguric renal failure (serum creatinine 1240 µmol/L), and nephrotic range proteinuria. Computed tomography of the abdomen revealed nephromegaly and no obstruction. The patient was admitted to the intensive care unit (ICU) and conventional hemodialysis was initiated. To avoid rapid sodium correction, we prescribed concurrent dialysate flow, a low dialysate sodium concentration, a small surface area dialyzer, and a low blood flow rate. We infused dextrose 5% water into the venous return line and adjusted the infusion rate according to hourly sodium concentration. The rate of sodium correction was 7.7 mmol/day over the first 3 days of admission. A subsequent renal biopsy revealed focal segmental glomerulosclerosis and interstitial infiltration with extranodal NK/T-cell lymphoma nasal type. The patient died of massive lower gastrointestinal bleeding secondary to lymphomatous involvement day 19 in the ICU. In the setting of acute kidney injury requiring renal replacement therapy and concomitant severe hyponatremia, it is challenging to avoid overcorrection of serum sodium. We describe several key prescription modifications to conventional hemodialysis, factors that affect sodium diffusion at the level of the dialyzer membrane, and the importance of frequent laboratory monitoring.

Outcomes of vascular access creation prior to dialysis: building the case for early referral.

A 2-year single institution experience of the successes and complications of arteriovenous fistula (AVF) creation before dialysis initiation is reported. Study cohort: all patients who underwent AVF creation before need for dialysis (AVF group, n = 125). "Control" group: all patients with a sustained glomerular filtration rate (GFR) 12 months in both groups and mean eGFR at creation (AVF group) was 12 ml/min. In the AVF group, 72% underwent a successful first AVF creation, 11% suffered AVF thrombosis, and 17% had a nonmaturing AVF before need for dialysis. Sixty-six percent (n = 23) of these latter patients underwent a second AVF creation and 48% were mature at dialysis initiation. During the study period, 70% (n = 88, AVF group) and 61% (n = 121, no AVF group) commenced dialysis. Impressively, 72% (n = 66) of the AVF group used a mature fistula as their first dialysis access. A snapshot of "access in use" at the 6-month mark of dialysis revealed the AVF group had a higher number of patients using an AVF (81% vs. 44%) and a lower number with catheters (19% vs. 56%, respectively, p = 0.001). In conclusion, the success rate of early AVF creation is reasonable and complications when identified can be remedied without the need for a catheter, thus ultimately maximizing the use of AVF in dialysis patients.