Randomised controlled trial and cost consequences study comparing initial physiotherapy assessment and management with routine practice for selected patients in an accident and emergency department of an acute hospital.

OBJECTIVE: The Department of Health is reviewing the effectiveness of accident and emergency (A&E) departments. This study aimed to compare health and economic effects of physiotherapy initial assessment and management with routine practice in an A&E department. METHODS: Randomised controlled trial and cost and consequences study. Patients presenting at A&E were eligible if suspected at triage to have soft tissue injury without fracture. The efficacy end point was "days to return to usual activities". Secondary end points included patient satisfaction with their care and further health outcomes and cost data. RESULTS: 766 of 844 (915) patients were randomised. The median days before return to usual activities (available for 73% of those randomised) was greater in the physiotherapist group (41 days compared with 28.5 days; hazard ratio 0.85 p = 0.071). The physiotherapy group expressed greater satisfaction with their A&E care (on a scale of 1 to 5, median was 4.2 compared with 4.0, p<0.001), were more likely to be given advice and reassurance, and more likely to be provided with aids and appliances. Costs were the same between the two arms. CONCLUSION: There is evidence that physiotherapy leads to a prolonged time before patients return to usual activities. This study shows no clear danger from physiotherapy intervention and long term outcomes may be different but given these findings, a best estimate is that introducing physiotherapist assessment will increase costs to the health service and society. Routine care should continue be provided unless there is some reason why it is not feasible to do so and an alternative must be found.

Formation of natural pH gradients in a microfluidic device under flow conditions: model and experimental validation.

A new isoelectric focusing technique has been developed that incorporates natural pH gradient formation in microfluidic channels under flowing conditions. In conjunction, a one-dimensional finite difference model has been developed that solves a system of algebraic-ordinary differential equations that describe the phenomena occurring in the system, including hydrolysis at the electrodes, buffering effects of weak acids and bases, and mass transport due to both diffusion and electrophoresis. A quantitative, noninvasive, optically based method of monitoring pH gradient formation is presented, and the experimental data generated by this method are found to be in good agreement with model predictions. In addition, the model provides a theoretical explanation for initially unexpected experimental results. Model predictions are also shown to match well with experimental results of microfluidic isoelectric focusing of a single protein species. Accounting for the nonuniform velocity profile, characteristic of pressure-driven flow in microfluidic channels, is found to improve predictions of dynamic pH changes close to the electrodes and overall time required to reach steady state, but to reduce the accuracy of dynamic pH change predictions in other regions of the channel.

Triage nurse requested x rays--the results of a national survey.

OBJECTIVE: To ascertain the prevalence and experiences of triage nurse requested x ray systems among accident and emergency (A&E) departments in the UK. METHOD: A descriptive study of a postal survey of 225 major A&E departments listed in the British Association for Accident and Emergency Medicine directory. RESULTS: Altogether 165 (73%) questionnaires were returned. Fifty nine (35%) departments indicated that they currently had a triage nurse requested radiology system. Of those departments that did not have such a system, the main reasons were that it was not necessary, radiologists or A&E consultants were opposed to the idea, that nurses were not capable/did not want the system, or that it would delay triage. Of those departments that do operate a nurse requesting system, most have started doing so in the last three years, and allow nurses of E grade and above who have completed an in house training course and radiation protection certificate to request x rays. Protocols vary, but usually allow requests for limb radiology in patients over 5 years old. Many departments have audited their system, with positive results. In all departments that currently operate the system, staff and patients felt that the system was either good or excellent. One department abandoned the system, after a trial, because they felt that x ray requesting was not a nursing role. CONCLUSION: The system of triage nurse requested x rays is generally well received and departments considering adopting this system can be reassured. Pitfalls and possible protocols for A&E departments intending to start triage nurse requested x rays are suggested.

Triage nurse requested x rays--are they worthwhile?

OBJECTIVE: To study an established triage nurse x ray requesting system to determine whether sending defined groups of patients for radiography before assessment by doctors or emergency nurse practitioners (ENPs) resulted in shorter waiting times for patients without compromising quality of care. METHODS: Prospective randomised controlled study of "walking wounded" patients attending a district general hospital. Data were collected over two separate two week periods, six months apart, in the middle of two senior house officer appointment periods. A total of 675 patients were entered into the study. Analysis of results was achieved using standard statistical methods. RESULTS: Altogether 335 patients were in the nurse x ray group and 340 in the control group. The triage categories of the groups were similar. A 36% mean time reduction of 37.2 min (95% confidence interval 30.2 to 44.2, p=0.000) from time of triage to time of treatment decision was achieved in the nurse requested group. Triage nurses requested 8% (p=0.002) fewer x rays than doctors or ENPs and had a 6% higher positive "hit" rate (p=0.03). In 7.8% (26 cases), patients in the triage nurse group were judged to require radiographs or further views by the doctor or ENP; of these, 11 cases showed a positive finding on radiography. The time from triage to assessment by doctor or ENP was not lengthened by prior requesting of radiography (nurse x ray group 64.4 min, control group 63.7 min, p=0.79). CONCLUSIONS: A triage nurse x ray requesting system speeds up the progress of walking wounded patients through the department without compromising service quality. Further benefits are staff and patient satisfaction and a greater sense of team working for all staff.

Quantitative analysis of molecular interaction in a microfluidic channel: the T-sensor.

The T-sensor is a recently developed microfluidic chemical measurement device that exploits the low Reynolds number flow conditions in microfabricated channels. The interdiffusion and resulting chemical interaction of components from two or more input fluid streams can be monitored optically, allowing measurement of analyte concentrations on a continuous basis. In a simple form of T-sensor, the concentration of a target analyte is determined by measuring fluorescence intensity in a region where the analyte and a fluorescent indicator have interdiffused. An analytical model has been developed that predicts device behavior from the diffusion coefficients of the analyte, indicator, and analyte--indicator complex and from the kinetics of the complex formation. Diffusion coefficients depend on the local viscosity which, in turn, depends on local concentrations of all analytes. These relationships, as well as reaction equilibria, are often unknown. A rapid method for determining these unknown parameters by interpreting T-sensor experiments through the model is presented.

Mathematical modeling of normal pharyngeal bolus transport: a preliminary study.

Dysphagia (difficulty in swallowing) is a common clinical symptom associated with many diseases, such as stroke, multiple sclerosis, neuromuscular diseases, and cancer. Its complications include choking, aspiration, malnutrition, cachexia, and dehydration. The goal in dysphagia management is to provide adequate nutrition and hydration while minimizing the risk of choking and aspiration. It is important to advance the individual toward oral feeding in a timely manner to enhance the recovery of swallowing function and preserve the quality of life. Current clinical assessments of dysphagia are limited in providing adequate guidelines for oral feeding. Mathematical modeling of the fluid dynamics of pharyngeal bolus transport provides a unique opportunity for studying the physiology and pathophysiology of swallowing. Finite element analysis (FEA) is a special case of computational fluid dynamics (CFD). In CFD, the flow of a fluid in a space is modeled by covering the space with a grid and predicting how the fluid moves from grid point to grid point. FEA is capable of solving problems with complex geometries and free surfaces. A preliminary pharyngeal model has been constructed using FEA. This model incorporates literature-reported, normal, anatomical data with time-dependent pharyngeal/upper esophageal sphincter (UES) wall motion obtained from videofluorography (VFG). This time-dependent wall motion can be implemented as a moving boundary condition in the model. Clinical kinematic data can be digitized from VFG studies to construct and test the mathematical model. The preliminary model demonstrates the feasibility of modeling pharyngeal bolus transport, which, to our knowledge, has not been attempted before. This model also addresses the need and the potential for CFD in understanding the physiology and pathophysiology of the pharyngeal phase of swallowing. Improvements of the model are underway. Combining the model with individualized clinical data should potentially improve the management of dysphagia.

Efficient numerical methods for nonlinear-facilitated transport and exchange in a blood-tissue exchange unit.

The analysis of experimental data obtained by the multiple-indicator method requires complex mathematical models for which capillary blood-tissue exchange (BTEX) units are the building blocks. This study presents a new, nonlinear, two-region, axially distributed, single capillary, BTEX model. A facilitated transporter model is used to describe mass transfer between plasma and intracellular spaces. To provide fast and accurate solutions, numerical techniques suited to nonlinear convection-dominated problems are implemented. These techniques are the random choice method, an explicit Euler-Lagrange scheme, and the MacCormack method with and without flux correction. The accuracy of the numerical techniques is demonstrated, and their efficiencies are compared. The random choice, Euler-Lagrange and plain MacCormack method are the best numerical techniques for BTEX modeling. However, the random choice and Euler-Lagrange methods are preferred over the MacCormack method because they allow for the derivation of a heuristic criterion that makes the numerical methods stable without degrading their efficiency. Numerical solutions are also used to illustrate some nonlinear behaviors of the model and to show how the new BTEX model can be used to estimate parameters from experimental data.

Decreasing the risk of human immunodeficiency virus or hepatitis B virus infection during endoscopic surgery.

The risk of transmission of human immunodeficiency virus and hepatitis B virus infection is small but finite. Urological surgeons are exposed through needle punctures in open surgery and splashes during endoscopic surgery. Safety glasses are difficult to use during endoscopic surgery and they do not offer complete protection. The Steri-Shield, a facial shield designed to be fixed to the endoscope, is described.

Interaction energies in the coagulation of calcium oxalate monohydrate.

In the present work, Gregory's approximation was used to calculate the Hamaker constant (A131) for the van der Waals interactions between calcium oxalate monohydrate (COM) particles in water. An average value of 1.135 (+/- 0.341) x 10(-20) J for A131 was calculated for COM particles at 37 degrees C in aqueous solutions. Theoretical calculations predicting coagulation behavior based on the calculated A131 are consistent with experimental data.

Extracorporeal shock-wave lithotripsy in horseshoe kidneys.

Using the Dornier HM-3 lithotriptor, 10 patients (11 renal units) with calculi in horseshoe kidneys were treated with extracorporeal shock-wave lithotripsy (ESWL) and ancillary procedures. Six renal units (55%) underwent pre-ESWL manipulation consisting of a Double J stent, ureteral catheter, or percutaneous nephrostomy. The "blast path" was employed to treat five renal units which could not be positioned at F2. Good initial stone fragmentation was obtained in eight renal units (73%). There were two episodes of post-ESWL obstruction requiring intervention; both occurred in the same patient. A total of seven post-ESWL procedures were performed on two renal units. After all procedures, eight renal units (73%) were rendered stone-free, six (55%) with ESWL alone. The average follow-up interval was twelve months (range 1-28 months). ESWL can be used effectively to treat some patients with calculi in horseshoe kidneys. The ectopic location of these renal units may make it difficult to position calculi at F2, thus necessitating treatment on the blast path or placement of the patient in prone position. Multiple ancillary procedures may be necessary.

Renal transplantation: a 20-year experience at the University of Florida.

Substantial gains have been made in both patient and graft survival during 20 years of transplanting kidneys at the University of Florida. The number of transplant recipients yearly has increased from six in 1966 to more than 100 in 1986. The use of immunosuppression reflects our evolving understanding of transplant immunology, with current morbidity and mortality rates considerably improved over those of the early years. This paper summarizes our transplantation experience over the past two decades.

A review of trauma deaths in an accident and emergency department.

There were 56 deaths following trauma in the adult Accident and Emergency Department of the University Hospital, Nottingham, over a 5-year period from 1983 to 1987. Forty-six of these deaths followed road-traffic accidents. The trauma deaths made up 16% of all adult deaths and 0.13 per thousand new attenders. We found evidence of inappropriate management in four cases, all relating to inadequate volume replacement. In two patients, the degree of hypovolaemia was not appreciated and in the other two, volume replacement was not commenced within 30 min of arrival in the department. Prompt treatment of hypovolaemic shock with appropriate fluids in adequate quantities cannot be overemphasized.

Overview of surgical treatment of urolithiasis with special reference to lithotripsy.

In the early 1980s, 2 elegant innovations were added to open surgery in the management of stones: endourology and extracorporeal shock wave lithotripsy. The decision strategy for treating stones is not yet codified and it depends on several factors, such as equipment, type and size of stones, needs of the patient and skills of the surgeon. After open stone surgery convalescence lasts approximately 4 to 6 weeks and repeated surgery is more difficult. With endourology convalescence can be reduced to a few days in an uncomplicated case, the risk of complication is approximately 10 per cent and retreatment is not more complicated. Convalescence with extracorporeal shock wave lithotripsy often is negligible and some extracorporeal shock wave lithotripsy units are run on an outpatient basis. However, as with all stone surgeries, extracorporeal shock wave lithotripsy causes renal bleeding of varying degrees. There are reports of diastolic hypertension after extracorporeal shock wave lithotripsy in up to 8 per cent of the patients. Retreatment is easy but the late consequences of retreatment are unknown. Extracorporeal shock wave lithotripsy is the dominant means of surgical management for stones in the western world; 87 per cent of our patients are treated with extracorporeal shock wave lithotripsy and 4 per cent with open surgery.

A model system for assessing physicochemical factors affecting calcium absorbability from the intestinal tract.

An in vitro model system was utilized to critically examine physicochemical factors that could play a role in determining the amount of potentially absorbable ionic calcium as well as soluble complexes in the proximal jejunum following ingestion of tricalcium dicitrate, calcium carbonate, or tricalcium diphosphate. The solubility of calcium salts (500 mg calcium each) was tested in 300 ml water containing varying amounts of hydrochloric acid (0, 0.72, 2.4, 7.26, and 24.2 mEq) intended to mimic achlorhydric to peak acid secretory states. Whereas 20% of calcium citrate dissolved in the absence of hydrochloric acid, a negligible amount of calcium carbonate and calcium phosphate underwent dissolution. In solutions containing 0.72-7.26 mEq hydrochloric acid, calcium citrate was more than twofold soluble than calcium carbonate, and calcium phosphate had intermediate solubility. At simulated peak acid secretion, all three salts were completely soluble, or nearly so. To simulate pancreatic bicarbonate secretion, the filtrates obtained from solubility studies were titrated to pH 5, 6, and 7 with sodium hydroxide. Reprecipitation of calcium citrate and calcium carbonate did not occur. However, substantial calcium phosphate reprecipitation took place especially at high pH and in filtrates derived from high hydrochloric acid content. In filtrates derived from reprecipitation experiments (at pH 6 and 7), anionic complexation of calcium was calculated in order to estimate the amount of ionic and complexed calcium. Considerable amount of calcium from dissolved calcium citrate was complexed (60-65%), principally as soluble CaCit-, whereas calcium complexation was negligible in the calcium carbonate and calcium phosphate systems.

Use of the computer program EQUIL to estimate pH in model solutions and human urine.

The computer program EQUIL was designed to calculate relative supersaturations of solute components of common urinary stones. In an extended software version, quantitative consideration of charge balance for a priori or a posteriori pH estimation was added. The reliability of this computation was tested with hydrogen ion titration of buffer solutions containing HEPES [N-(2-hydroxyethyl)piperaizine-N'-ethanesulfonic acid] as well as samples of normal human urine. In the model solutions with HEPES, the difference between calculated pH values and the measured pH was smaller than 1.2% for any titration step within the buffer zone (pH 8.5-6.8). The pH values calculated for whole urine differed from the measured pH by 7% to 53%, and the calculated charge inbalance ranged from 2.6 to 9.6 mM. This net cation inbalance indicates that there is a need to account for other anionic components, including hippurate, amino acids, and isocitrate. In experimental solutions, charge balance calculations with EQUIL can be of great utility because they permit a priori estimation of pH or computation of the composition at a desired pH.