The availability,condition and employability of automated external defibrillators in large city centres in the Netherlands

Background

In the Netherlands there are, at the time of writing, no clear guidelines about the implementation of automated external defibrillators (AEDs). An observational study was conducted to investigate the current status of AEDs in city centres in the Netherlands looking specifically at the availability, condition and employability of the AEDs.

Methods and results

The shopping areas in the old city centres of the six largest cities in the Netherlands were included in the study. After the AEDs had been identified, a questionnaire was used to determine the availability, condition and employability of the AED. In total 130 AEDs were found and 122 included in the study. The following results were found: 40% of the AEDs were not visible (range 21–64), 29% were not indicated with a sign (range 19–41), 7% had an empty battery (range 0–23), 16% of the defipads had expired (range 0–31) and in 98% of the AEDs a trained employee was present (range 96–100). After combining these results, 71% of the AEDs were available for use (range 61–93), 70% were in a good condition (range 46–82) and 70% were employable (range 58–93). The results show a major variability between cities.

Conclusion

Our study demonstrates that although national guidelines have not been implemented, a reasonable amount of AEDs can be found. However there is certainly room for improvement in the current availability, condition and employability of AEDs in city centres in the Netherlands.     

Hypocalcaemia in severe meningococcal infections

AIM: To determine the incidence of hypocalcaemia in critically ill children with meningococcal disease. METHODS: In a prospective cohort study, 70 of 80 patients admitted consecutively with a clinical diagnosis of meningococcal disease to intensive care had measurements of total and ionised calcium on admission. Parathormone and calcitonin were measured in a proportion of the children. RESULTS: Total and ionised calcium concentrations were low in 70% of the children. There was a weak relation of calcium concentration to the volume of blood derived colloid which had been given, but a good relation to disease severity, where sicker children had lower calcium concentrations. Although the parathormone concentration was higher in children with lower calcium concentrations, some children had low ionised calcium concentrations, without an increase of parathormone concentration. Serum calcitonin concentration was not related to calcium concentrations. CONCLUSION: Hypocalcaemia is common in meningococcal disease.     

Conductance Method for the Measurement of Cross-Sectional Areas of the Aorta

A modified conductance method to determine the cross-sectional areas (CSAs) of arteries in piglets was evaluated in vivo. The method utilized a conductance catheter having four electrodes. Between the outer electrodes an alternating current was applied and between the inner electrodes the induced voltage difference was measured and converted into a conductance. CSA was determined from measured conductance minus parallel conductance, which is the conductance of the tissues surrounding the vessel times the length between the measuring electrodes of the conductance catheter divided by the conductivity of blood. The parallel conductance was determined by injecting hypertonic saline to change blood conductivity. The conductivity of blood was calculated from temperature and hematocrit and corrected for maximal deformation and changes in orientation of the erythrocytes under shear stress conditions. The equations to calculate the conductivity of blood were obtained from in vitro experiments. In vivo average aortic CSAs, determined with the conductance method CSA _(G) in five piglets, were compared to those determined with the intravascular ultrasound method CSA_(IVUS). The regression equation between both values was CSA _(G) =–0.09+1.00·CSA_(IVUS) r=0.97, n=53. The mean difference between the values was –0.29% · 5.57% (2 standard deviations). We conclude that the modified conductance method is a reliable technique to estimate the average cross-sectional areas of the aorta in piglets. © 1999 Biomedical Engineering Society. PAC99: 8780-y, 8437+q, 8719Nn     

Identification of malaria hot spots for focused intervention in tribal state of India: a GIS based approach

Background  

In India, presently malaria shows a declining trend whereas Plasmodium falciparum (Pf) cases show an up trend. In central India, specifically, Madhya Pradesh (M.P.) a forested and tribal area, control of malaria is logistically difficult and outbreaks are frequently recorded, reasons for this being inadequate surveillance, poor reporting, a time lag in reporting to decision makers and a lack of geo referenced information to pin point the trouble spots for a timely preventive action.     

On-line mapping system for the visualization of the electrical activation of the heart

A simple but still versatile datalogging system based on a VCR (video cassette recorder) has been developed. The VCR allows mass storage of data originating from a maximum of 256 channels as used, for example, in the recording of the time-dependent potential distribution at the surface of the myocardium [1,2]. Incorporated in the system is a display memory allowing on-line simultaneous visualization of the assessed recordings of 16 channels. On an interactive base display parameters (time-window, channel-selection) can be altered without loss of data. A link with a personal computer allows modification of system parameters and storage of data for off-line analysis of the recorded data. The high data rate to and from the VCR (4.3 MHz) fully utilizes the bandwidth available. A normal videotape can, therefore, contain up to 2 Gigabyte of data. Despite this, the use of the tapecounter and the decoding of the time-code inserted into the signal allows quick retrieval of the stored data without needing expensive equipment. The system described brings mass data logging within the reach of a vast number of laboratoria and cardiovascular centers.     

Preoperative cardiac testing before major vascular surgery

Conclusions  Preoperative risk assessment with a noninvasive stress test (MPS or DSE) is necessary only in high-risk patients without unnecessary delay for vascular surgery. High-risk patients can easily be selected through the risk score index. Prophylactic revascularization should only be performed in those with unstable coronary artery disease. The optimal perioperative medical treatment, especially tight heart-rate control, is essential for decreasing perioperative and postoperative cardiac risk.     

Musculoskeletal modelling in determining the effect of botulinum toxin on the hamstrings of patients with crouch gait

This study aimed to determine the effect of hamstring botulinum toxin A (Btx-A) injection in 10 children with crouch gait in terms of changes in muscle length and lower-limb kinematics. Before Btx-A injection limb kinematics were recorded. Maximum hamstring lengths and excursions were calculated by computer modelling of the lower limb. Data were compared with the averaged hamstring lengths of 10 control children. Hamstrings were denned as short if their length was shorter than the average maximum length minus one standard deviation. Gait analysis was repeated 2 weeks after isolated hamstring Btx-A injection. Pre- and postinjection kinematic data and muscle lengths were then compared. Four of 18 injected limbs in three subjects had short medial hamstring before injection, none of the subjects had short lateral hamstrings. Muscle excursion was significantly reduced in the short and adequate maximum muscle length groups. A significant increase in the semimembranosus and semitendinosus length in all of the injected limbs was noted. Only in the short muscle group was a significant increase in muscle excursion observed. Knee extension improved by 13° in the adequate muscle length group and by 15.6° in the short muscle length group. Pelvic tilt and hip flexion increased in both groups non-significantly. Average walking speed postinjection increased from 0.60 ms^-1 to 0.71 ms^-1. Short hamstrings are over-diagnosed in crouch gait. Hamstring Btx-A injection in patients with crouch gait produces significant, repeatable muscle lengthening and improved ambulatory function.