Amnon Gil

Performance of Infusion Pumps during Hyperbaric Conditions

Background Many hyperbaric facilities use infusion pumps inside the chamber. It is therefore important to ensure that this equipment will perform accurately during hyperbaric conditions. The authors tested the function and accuracy of the Imed 965 and Infutec 520 volumetric infusion pumps, the Easy-pump MZ-257 peristaltic infusion pump, and the Graseby 3100 syringe pump. Methods The authors calculated the deviations of infused volumes at low and high rates (12–18 and 60–100 ml/h) on three different hyperbaric protocols (up to 2.5, 2.8, and 6 atmospheres absolute [ATA]), resembling a standard hyperbaric oxygen treatment and US Navy treatment tables used for decompression illness and for arterial gas embolism. Two examples of each pump model were examined in every experiment. Results The Easy-pump MZ-257 failed to function completely beyond a chamber pressure of 1.4 ATA, making it unsuitable for use inside the hyperbaric chamber. The Graseby 3100 failed to respond to all keyboard functions at 2.5–2.8 ATA, making it unsuitable for use in most hyperbaric treatments. The Imed 965 performed within an acceptable volume deviation (≤10%) during most hyperbaric conditions. During the compression phase of the profiles used, and for the low infusion rates only, exceptional volume deviations of 20–40% were monitored. The Infutec 520 demonstrated an acceptable deviation (within 10%) throughout all the hyperbaric profiles used, unaffected by changes in ambient pressure or infusion rate. Conclusions Commercially available infusion pumps operating during hyperbaric conditions demonstrate substantial variations in performance and accuracy. It is therefore important that the hyperbaric facility staff make a careful examination of such instruments to anticipate possible deviations in the accuracy of the equipment during use.

Artificial Horizon Effects on Motion Sickness and Performance

Hypothesis To investigate whether the projection of Earth-referenced scenes during provocative motion can alleviate motion sickness severity and prevent motion sickness-induced degradation of performance. Background Exposure to unfamiliar motion patterns commonly results in motion sickness and decreased performance. Methods Thirty subjects with moderate-to-severe motion sickness susceptibility were exposed to the recorded motion profile of a missile boat under moderate sea conditions in a 3-degrees-of-freedom ship motion simulator. During a 120-minute simulated voyage, the study participants were repeatedly put through a performance test battery and completed a motion sickness susceptibility questionnaire, while self-referenced and Earth-referenced visual scenes were projected inside the closed simulator cabin. Results A significant decrease was found in the maximal motion sickness severity score, from 9.83 ± 9.77 (mean ± standard deviation) to 7.23 ± 7.14 (p < 0.03), when the visual display better approximated the full scale of the roll, pitch, and heave movements of the simulator. Although there was a significant decrease in sickness severity, substantial symptoms still persisted. Decision making, vision, concentration, memory, simple reasoning, and psychomotor skills all deteriorated under the motion conditions. However, no significant differences between the projection conditions could be found in the scores of any of the performance tests. Conclusion Visual information regarding the vessel’s movement provided by an artificial horizon device might decrease motion sickness symptoms. However, although this device might be suitable for passive transportation, the continued deterioration in performance measures indicates that it provides no significant advantage for personnel engaged in the active operation of modern vessels.

Safety of double-dose transdermal scopolamine.

Study Objective. To evaluate the safety of double‐dose transdermal scopolamine patch therapy.

A comparison of cinnarizine and transdermal scopolamine for the prevention of seasickness in naval crew: a double-blind, randomized, crossover study.

ObjectivesThe objective of the study was to compare the efficacy of transdermal scopolamine and cinnarizine in the prevention of seasickness and their adverse reactions. MethodsSeventy-six naval crew members participated in a double-blind, randomized, crossover study. On 2 voyages, they were administered either a transdermal scopolamine patch containing 1.5 mg scopolamine and placebo tablets or 25-mg cinnarizine tablets and a placebo patch. Subjects completed questionnaires for each voyage, reporting on the efficacy of the drugs, the severity of their adverse reactions, and the preferred treatment. ResultsSubjects reported the scopolamine patch to be significantly more effective than the cinnarizine tablet (P = 0.029). A moderate to high degree of drowsiness was attributed more frequently to cinnarizine than to the scopolamine patch (34% and 17%, respectively; P < 0.02). Any adverse reaction, to at least a moderate degree, was more frequent with cinnarizine (38%) than with the scopolamine patch (22%), although the significance of this association was borderline. A significantly greater percentage of subjects preferred transdermal scopolamine to cinnarizine (41 vs 12%, P < 0.001). ConclusionsHigher efficacy, a lower rate of adverse reactions, and convenience all led the participants of this study to prefer the scopolamine patch to cinnarizine. Considering the 2 therapeutic options assessed in this study, and in light of the findings of previous studies, it is recommended that the scopolamine patch be used as the drug of choice for the treatment of seasickness among naval crew in particular and probably also among all other sea travelers.

Vestibular Neuronitis in Pilots: Follow‐up Results and Implications for Flight Safety

Objectives To report our experience over the past 12 years with the evaluation and follow‐up of pilots with vestibular neuronitis and to discuss points relevant to flight safety and the resumption of flying duties.