The effects of antivenom and verapamil on the haemodynamic actions of Chironex fleckeri (box jellyfish) venom

The efficacy of antivenom and verapamil against Chironex fleckeri (box jellyfish) venom was investigated in monitored mechanically ventilated piglets. Chironex fleckeri tentacle extract alone, a mixture of tentacle extract with antivenom, and verapamil before tentacle extract were administered intravenously to groups of animals. Tentacle extract caused severe systemic hypotension, cardiac dysrrhythmias, pulmonary hypertension, haemolysis and hyperkalaemia. These effects were prevented by pre-incubation of tentacle extract with antivenom. Verapamil did not prevent any effect of venom, exacerbated cardiovascular collapse and increased mortality. We conclude that antivenom neutralizes the cardiovascular, haemolytic and hyperkalaemic effects of box jellyfish venom. Verapamil does not prevent any of these effects and is contra-indicated for treatment of envenomation.

When the balloon goes up: the materials technology of balloon catheters

Balloons and catheters together form an increasingly important combination in diagnostic and therapeutic minimally invasive procedures. This article discusses how these simple devices have risen in stature over the last decade.

The use of cold compression dressings after total knee replacement: a randomized controlled trial

This prospective, controlled study compared cold compressive dressings with wool and crepe in the postoperative management of patients undergoing total knee replacement (TKR). Forty TKR patients were assessed for blood loss, pain, swelling, and range of motion. Patients in the cold compression group had less blood loss through suction drainage (982 mL versus 768 mL). A higher proportion of patients in the treatment group did not require blood transfusion postoperatively. Mean opiate requirements were lower in the cold compression group (0.57 versus 0.71 mg/kg/48 hours). The cold compression device appeared to reduce blood loss and pain following TKR.

Resident perspectives of EMS as a subspecialty

OBJECTIVE

Emergency medical services (EMS) is frequently considered to be a subspecialty of emergency medicine (EM) despite the unavailability of subspecialty certification. An assessment of future interest in EMS subspecialization and the perceived educational needs of potential EMS physicians was performed in order to provide data to leaders responsible for development of this subspecialty area.

METHODS

A survey concerning EMS subspecialization issues was distributed to 2,464 members of the Emergency Medicine Residents Association (EMRA). Questions addressed demographic information, interest in EMS, educational issues, and desired credentials. The response rate was 30% (n = 737). All surveys were analyzed by the Pearson chi-square probability and Mantel-Haenszel tests for linear association.

RESULTS

A moderate to very high interest in EMS medical direction was expressed by 84% of the respondents, with 14% interested in full-time EMS positions. This interest increased with years of training (p < 0.0001). Almost 89% believed that EMS physicians should have special preparations prior to practice beyond EM residency training. Fewer than half (44%) thought that an EM residency provided sufficient preparation for a significant role in EMS, and this perception increased in intensity with years of training (p < 0.0052). Interest in EMS fellowships (24%) would increase to 36% if subspecialty certification were available (p < 0.0001). Thirty-nine percent believed subcertification should be required of all EMS medical directors if available.

CONCLUSIONS

Many EM residents have an interest in active participation in EMS on either a part-time or a full-time basis. Most respondents think EMS is a unique area requiring focused education beyond an EM residency. Interest in EMS fellowships would greatly increase if subspecialty certification were available.

Engineering a concept: the creation of tissue engineering

Tissue engineering is a fashionable phrase and a new concept. This article analyses what is meant by this term and discusses some of the products that may emerge from the translation of this concept into clinical reality.

Gowning: effects on patient satisfaction

BACKGROUND

Given an extensive literature regarding the doctor-patient relationship, it appears curious that gowning status has received so little attention. The present study examined potential effects of gowning as opposed to not gowning patients at the point of presenting problem. Specifically, effects that gowning status might have on patients' trust in their physician, as well as overall duration of clinic visit, were investigated.

METHODS

Patients (N = 1500) were randomly assigned to gown or non-gown status on arrival for clinic visit. Subsequent screening following predetermined guidelines resulted in 895 subjects participating in the study. Fifty-one percent of these patients (n = 455) fully completed the Trust in Physician Scale. Total time data from check-in to checkout, by gowning status, were kept on all patients.

RESULTS

No significant effects for gowning status were found with respect to patients' trust in their physician or duration of clinic visit. There were also no significant interactions between gowning status, patient sex, physician sex, patient age, or patient education. Significant findings were demonstrated whereby younger patients and patients seeing a doctor for the first time reported less trust in their physician.

CONCLUSIONS

There is not sufficient evidence, to date, to suggest that gowning status has a significant impact on the doctor-patient relationship or the duration of clinic visit.

Size and shape really matter: the influence of design on biocompatibility

Biocompatibility is normally equated with the characteristics of degradation and toxicity. However, there are many more ways by which a medical device can affect the host, including the way in which devices distribute stress in the tissues. This in turn implies that the design of the device can be influential in determining the host response.

Ceramics transformed: manipulating crystal structures to toughen bioceramics

Ceramics have tremendous potential as engineering materials for the construction of medical devices but are inhibited by their inherent brittleness. This article discusses how this problem has been addressed by the development of the process of transformation toughening and places this in the broader context of the new generation of "smart" materials.

Paroxetine increases heart rate variability in panic disorder

Panic patients have decreased heart rate variability, a risk factor for sudden cardiac death, and increased rates of cardiac death and stroke. Imipramine has been found to further reduce heart rate variability in panic. This study uses power spectral analysis to compare autonomic components of heart rate variability in 16 unmedicated control subjects and 17 panic patients before and after treatment with paroxetine at 20 mg/day for 4 weeks. Patients had higher predrug reclining and standing sympathetic activity than control subjects. After drug, patients' total sympathetic activity decreased. Predrug patients failed to increase sympathetic activity on orthostasis, lacking the normal baroreflex response found in control subjects. After drug, patients normalized this sympathetic component of the baroreflex response. Before drug, patients' parasympathetic reclining and standing activity did not differ from control subjects, and patients showed the normal orthostatic parasympathetic decrease. After drug, patients' total parasympathetic activity increased, whereas the baroreflex response was preserved. Nine medicated patients had more than a 50% reduction of panic attacks. In view of paroxetine's increase of heart rate variability, potential benefits of selective serotonin reuptake inhibitors in decreasing cardiac mortality in panic disorder are discussed.

The engineering of polysaccharides

Hyaluronan is a widely distributed and very important biological molecule of the polysaccharide family. Many of the functional characteristics of this substance can be retained when hyaluronan is transformed from a water-soluble substance into a structural biomaterial. This article highlights the potential applications of these materials in the regeneration of injured tissue.

Morphological and structural characteristics of the proximal femur in human and rat

Because the ovariectomized rat model of postmenopausal osteoporosis is the most commonly used small animal model to investigate consequences of bone loss on bone structure and strength, or to assess benefits of the various therapeutic strategies to improve bone mass and strength, the attempt was made to compare histoanatomical and structural characteristics of the femoral neck between human and rat models. In addition to different biomechanics, there is a significant difference in gross- and microanatomy of the proximal femur between humans and rats. Percent of the cortical bone component is much higher in rats (72.5%) relative to humans (12.5%). Also, cortical bone at the femoral neck in rats is evenly distributed, whereas in humans there is a considerable difference in the amount of the cortical bone between the superior half of the femoral neck with cortical thickness being only 0.3 mm, and the inferior half of the neck having 6-mm-thick cortex. Humans have far more cancellous bone at the femoral neck (22.7% average) relative to rats (6.8%). In addition, cancellous bone at the femoral neck in humans is unevenly distributed between the bone center and its periphery. Human samples exhibited striking differences in the cancellous bone structure between weight-bearing and tensile trabecular groups exhibiting clear trabecular orientation consisting of plates and rods, and trabeculae around the neutral bone axis with little mechanical activity exhibiting rod-like trabeculae only. Although humans and rats have a periosteum covering the femoral neck, and each lacks the muscular attachment at intracapsular portions of the femoral neck, rats, in contrast to humans, have the ability to quickly adapt cortical thickness and increase inertia to meet mechanical needs via modeling-dependent periosteal apposition.