Use of single-frequency bioimpedance at 50 kHz to estimate total body water in patients with multiple organ failure and fluid overload

OBJECTIVE

To investigate the relationship between single-frequency bioimpedance at 50 kHz (both total body impedance and segmental impedance) and total body water, measured using tritiated water in the presence of the severe fluid retention seen in multiple organ failure.

DESIGN

Prospective, controlled study.

SETTING

General intensive care unit.

SUBJECTS

Twenty patients with multiple organ failure and 30 normal volunteers, of whom a subgroup of ten had total body water measured.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Total body water and total and segmental bioimpedance values at 50 kHz were measured using tritiated water and a Holtain body composition analyzer in 20 patients with multiple organ failure and in ten normal volunteers. An additional 20 normal volunteers also had segmental and total body impedance measured. There was no difference in the linear regression lines constructed for the patients and the volunteers, but the SEM in the patients (7.6 L) was four times that seen in the normal subjects (1.9 L). In a further seven patients, the impedance technique overestimated the change in total body water, deduced from acute changes in weight, by between 0% and 46% (median, 12%). In the patients, who were supine, the knee-ankle segment contributed significantly more to total body impedance than it did in the normal volunteers (42.5% vs. 34.4%; p < .001), who were upright and mobile immediately before the measurement.

CONCLUSIONS

Although single-frequency bioimpedance does give an indication of total body water and change in total body water, it is neither precise nor accurate enough to be the sole guide to fluid therapy. The proportion of total impedance contributed by the knee-ankle segment, which contains relatively little water, was significantly greater in the patients than in the controls, probably reflecting better drainage of fluid from the lower limb in the supine position.

A comparison of two airway aids for emergency use by unskilled personnel. The Combitube and laryngeal mask

Many non-anaesthetists find airway control and intubation difficult. The laryngeal mask has been advocated for use by non-anaesthetists at cardiorespiratory arrests, whilst the Combitube is said to provide protection from aspiration. We wished to determine which device was easiest for unskilled staff to use. Staff not previously trained in airway support were briefly taught insertion of each device. Twenty-six ASA 1 or 2 adults, requiring muscle relaxation and tracheal intubation for surgery, were recruited to this randomised crossover study. Both devices were inserted in random order and the time to successful ventilation of the lungs recorded. Both devices were successfully placed in 24/26 patients. The median times to insertion were 40 s and 45 s for the laryngeal mask and Combitube, respectively, with two failures, both with the Combitube (p > 0.05); these were due to faulty operator technique. The Combitube may be a suitable alternative to the laryngeal mask for use in resuscitation by unskilled staff.

An evaluation of intercostal nerve blockade for analgesia following renal transplantation

In a double-blinded study we examined the effect of supplementing patient-controlled morphine analgesia with intercostal nerve blockade to identify if this improved analgesia and reduced morphine requirements following renal transplantation. Fifty patients were randomized to receive unilateral intercostal nerve block with either 0.5% bupivacaine or saline to the lower five intercostal nerves. Each block was performed on the side of surgical incision following the completion of surgery. Patients receiving bupivacaine blockade reported reduced pain scores and used less morphine in the initial 4 h following renal transplantation, but did not demonstrate a significant reduction in overall pain scores, total 24 h morphine requirements, or sedation scores. Two patients developed a pneumothorax, neither of which were clinically apparent at the time of diagnosis, and only detected by chest radiography. A chest radiograph should therefore be considered mandatory after intercostal nerve blockade.

Drug resistance mechanisms and MRP expression in response to epirubicin treatment in a human leukaemia cell line

A drug resistant series of sublines were developed by treating the human leukaemia CCRF-CEM cell line with 16-1000 ng/ml of the anthracycline, epirubicin. The sublines developed resistance in two stages, neither involving detectable levels of P-glycoprotein. Treatment with up to 50 ng/ml epirubicin produced sublines with cross resistance limited to the anthracyclines and etoposide. Treatment with 100-1000 ng/ml epirubicin produced sublines with increased expression of the mrp gene, increased resistance to the anthracyclines and etoposide, additional cross resistance to vincristine and colchicine, decreased drug accumulation and reversal of resistance by verapamil and by buthionine sulphoximine (BSO; an inhibitor of glutathione synthesis). Our results indicate an interaction between MRP and glutathione metabolism as a mechanism for multidrug resistance.

Partners in policymaking: the first five years

Many individuals with disabilities and their families are becoming empowered by learning effective self-advocacy strategies. In this article one enpowerment and self-advocacy training program, Partners in Policymaking, for parents of young children and adults with disabilities was described. Initially developed in Minnesota, the Partners program has completed its fifth year, has 163 graduates, and is being replicated in several other states. Follow-up data, qualitative and quantitative, were collected from program graduates. Results indicated both satisfaction with the program and the presence of many active citizen-advocates in the community.