Measurement of acute edema shifts in human burn survivors--the reliability and sensitivity of bioimpedence spectroscopy as an objective clinical measure.

Improvements in treatment for acute burn edema have stalled in comparison with other areas of burn care. Designing acute edema treatment studies in humans is hindered by the lack of objective, sensitive methods of measurement in the burn population. Bioimpedence spectroscopy (BIS) is a noninvasive method of measuring fluid volumes in the body. The aim of this study was to examine the reliability and sensitivity of BIS in the measurement of acute edema shifts in burn survivors, including assessment across different wound conditions. BIS measurements were collected in triplicate from 21 burn patients in total. Phase I (n = 13) examined BIS under three different dressing conditions. Phase II (n = 8) considered only patients with dressings intact. Sensitivity (minimum detectable difference [MDD]) was examined with total body water, extracellular fluid (ECF), and intracellular fluid volume measurements. BIS demonstrated excellent reliability across all dressings conditions, including when open wounds were present (intraclass correlation coefficient = 0.975-1.00, 95% confidence intervals = 0.938-1.00). Clinically useful levels of sensitivity, or MDD, were calculated. BIS MDD for total body water (open wounds) = 360 ml, ECF (open wounds) = < or = 10 ml, ECF (new dressings) = 540 ml, and intracellular fluid (open wounds) = 310 ml. BIS analysis is clinically applicable for real-time, noninvasive monitoring of whole-body fluid shifts in acute burn survivors with < or = 30% TBSA.

Volume measurement using the Polhemus FastSCAN 3D laser scanning: a novel application for burns clinical research.

UNLABELLED: The Polhemus FastSCAN system offers a noncontact method of quantifying limb edema volume by combining laser scanning with 3D spatial orientation. The aim of this study was to investigate the reliability, validity and clinical utility of this assessment technique in the burn environment. Pilot Studies: Completed in order to develop a standardised scanning procedure. Intertester Reliability: Two testers each scanned 30 uninjured upper limbs. Intratester Reliability: One tester conducted repeated scans for burn survivors (n = 6). VALIDITY: The scan volumes were compared with water displacement measures for all volunteers (n = 36). Intertester reliability was moderate for whole arm scans (R = .59; 95% confidence intervals [CI] = 0.28-0.78) and excellent with hand truncated (R = .95; 95% CI = 0.90-0.98; minimum detectable difference = 242.1 cm3). Intratester reliability was inconclusive (R = .72; 95% CI = -0.07-0.96) but qualitative assessment confirmed poorer quality scans. The FastSCAN system overstated the arm volume by 49.3 cm3 on average, but 95% limits of agreement when compared with water displacement demonstrated the limitations as a clinical or research tool in the burn environment. The Polhemus FastSCAN system provides a noncontact method of limb volume measurement. The reliability was good only with the hand removed from calculations. The accuracy of the system compared poorly with water displacement measures in the burn clinical environment. Using the currently available software and method, the change detectable by this technique was too large for monitoring the efficacy of acute burn edema interventions.

The sugar glider (Petaurus breviceps): a laboratory host for the nematode Parastrongyloides trichosuri.

Parastrongyloides trichosuri is a nematode parasite of the Australian brush-tailed possums that can be propagated through many generations in vitro. This makes P. trichosuri uniquely suited for genetic investigations, including those involving transgenesis. However, an obstacle to its use as an experimental model has been the fact that its host is limited to Australia and New Zealand and that it cannot be exported because of its status as a protected species or agricultural pest, respectively. In previous studies, conventional laboratory animals such as rats, mice, rabbits, ferrets, and chickens have failed to support infections. In the present study, gerbils and short-tailed opossums proved similarly refractory to infection. In contrast, the sugar glider (Petaurus breviceps, family Petauridae) proved to be a good host for P. trichosuri. Patent infections resulted using as few as 6 infective larvae (L3i) and as many as 2,000 L3i. Large numbers of L3i (1,000-2,000) produced patent infections of much shorter duration than those seen when 100 L3i were initially given to the sugar glider. In one case, an infection initiated with 100 L3i was patent for over 1 yr. Parastrongyloides trichosuri is easily cryopreserved using a method developed for Strongyloides stercoralis. Thus, we have identified an experimental host for P. trichosuri that will make it possible to conduct research on this parasite in laboratories outside the endemic sites.

Ornithonyssus bacoti infestation and elimination from a mouse colony.

Skin lesions, consisting of nonspecific bites with intense pruritus and excoriation of the skin, were found on personnel working in an animal colony primarily housing mice. The tropical rat mite, Ornithonyssus bacoti, was diagnosed from mites trapped on insect-monitoring sticky traps and collected from mouse cages in the colony. Because these mites do not live on mice but only come to feed when the animals are in their nest, an initial attempt was made to eliminate the mites with a thorough cleaning of the facility. Clidox foam was applied to the entire room with a foaming machine. Then the mice were transferred into the sanitized cages in the cleaned room. The numbers of mites were reduced to the point that they were no longer noticed in the colony, but the mites returned within 2 weeks. The mites were successfully eliminated with the use of permethrin-impregnated cotton balls in the mouse cages for 8 weeks and treatment of the premises. Treatment of the premises included spraying floors and walls of all rooms housing mice and adjacent hallways in the colony with pyrethrin spray by a commercial pest control company. To prevent one room of rabbits from maintaining the infestation, they were treated weekly with an organic pyrethrin dust. Insect sticky traps have remained negative for mites for more than 3 years after treatment.

Plantar pressure and radiographic changes to the forefoot after the Austin bunionectomy.

We describe the effects of the Austin bunionectomy on plantar pressure distribution and radiographic measurements in the forefoot in 31 subjects (44 feet) with mild-to-moderate hallux valgus deformity and 36 control subjects (36 feet). Plantar pressure measurements before and 24 months after surgery showed peak pressure beneath the hallux reduced to normal values. Peak pressure measurements beneath the first, second, and third metatarsal heads in hallux valgus feet were relatively unchanged after surgery and remained higher than normal values. The operation produced significant decreases in mean preoperative radiographic measurements of hallux abductus, metatarsus primus varus, and first metatarsal protrusion distance in these patients to below-normal values.

Plantar pressure and joint motion after the Youngswick procedure for hallux limitus.

The effects of the Youngswick osteotomy on plantar peak pressure distribution in the forefoot are presented for 17 patients (23 feet) with mild-to-moderate hallux limitus deformity and 23 control subjects (23 feet). During 2 years of follow-up, the operation produced a significant increase in the range of dorsiflexion of the first metatarsophalangeal joint in these patients, reaching near-normal values. Preoperative and postoperative measurements, using a pressure-distribution measurement system, show that peak pressure beneath the hallux and the first metatarsal head remained unchanged. However, peak pressure was significantly increased beneath the second metatarsal head and decreased beneath the fifth metatarsal head. These findings suggest that the foot functioned in a less inverted manner postoperatively. Compared with normal feet, hallux limitus feet demonstrated significantly higher peak pressure beneath the fourth metatarsal head preoperatively and postoperatively.

Neuromotor development and the physiologic effects of positioning in very low birth weight infants.

OBJECTIVE: To provide a comprehensive literature review of neuromotor development and related physiologic effects of positioning in very low birth weight infants. DATA SOURCES: MEDLINE, CINHAL, Health Star, Current Contents, and the Australian Medical Index (1966-2000) databases were searched. Unpublished studies (e.g., dissertations, conference proceedings) and all relevant references listed in articles also were examined. STUDY SELECTION: One hundred and eighty theoretical writings, research studies, and clinical papers related to neuromotor development, the physiologic effects of positioning, and interventions to minimize or prevent short- and long-term effects of positioning in very low birth weight infants were reviewed. DATA EXTRACTION: Studies were assessed for scientific rigor, evidence of theoretical foundation, and clinical relevance. Comparisons were made across data sources to determine the most reliable, valid, and consistent findings. DATA SYNTHESIS: Three compelling results emerged: (a) The development of posture and mobility in newborn infants requires an optimal balance between active and passive muscle tone, (b) the prone position is physiologically more beneficial for the preterm infant than supine and lateral positions, and (c) the prone position can lead to short- and long-term postural and associated developmental problems. CONCLUSION: Use of empirically tested postural interventions appropriate for an infant's gestational age, health status, and overall organizational capacity is recommended.

Scarf ratio: A method of measuring the Scarf sign in preterm born infants.

A new method of measuring the Scarf sign called the Scarf ratio is described in which data derived were reported on a continuous scale. The Scarf ratio is the distance of the olecranon process of the arm being tested as it moves across the trunk compared with the infant's own biacromial width. Longitudinal data for the Scarf ratio were measured in a cohort of 111 Thai preterm born infants. The data were collapsed into four age ranges ie 28-31, 32-36, 37-39 and 40 weeks post-conceptional age (PCA) according to the trends from the longitudinal plots. As the means of the Scarf ratio increased with age, it can be described that the resistance to the passive movements of the arm increased when the infants grew up. Data were also converted to a newly developed categorical scoring system. All infants between the age of 28 and 31 weeks PCA recorded a score of 1 (low tone). Most infants aged 32-36 and 37-39 weeks PCA recorded a score of 2 while most infants aged 40 weeks PCA obtained a score of 3 (high tone). Thus, this method can be an alternative when continuous data for the Scarf sign are desirable.