Israel Medical Association Journal

Background: Decompression sickness (DCS) is a clinical syndrome caused by a substantial reduction in barometric pressure. DCS is more common among divers but may also occur during flight or altitude chamber (hypobaric chamber) training. DCS is classified according to symptoms as either Type 1 (musculoskeletal and skin involvement) or Type 2 (neurological and pulmonary involvement). DCS may be life threatening and often necessitates treatment with hyperbaric oxygen therapy (HBOT).

Objectives: To examine the risk for altitude decompression sickness (ADCS) in altitude chamber training and to compare ADCS symptoms and treatment to those of DCS in divers (DDCS).

Methods: We conducted a retrospective cohort study that included all cases of ADCS in the Israeli Air Force between 2015 to 2022. We collected demographic, flight platform, altitude chamber training, clinical manifestations, and treatment data. Data regarding DDCS was obtained via a literature review.

Results: There were 2279 altitude chamber trainees and aviation physiology instructors. Of these, 11 presented ADCS, leading to a calculated ADCS risk of 0.5%. An additional four cases were reported following combat flights. Musculoskeletal involvement was the most common symptom in both DDCS and ADCS. A shorter HBOT protocol was used in 53% of the ADCS cases but only in 30% of the DDCS cases.

Conclusions: Overall, ADCS is a rare event, occurring in less than 1% of altitude chamber trainees. The common manifestation is of musculoskeletal involvement, and the mainstay of treatment remains HBOT.

Serum sickness is an immune-complex-mediated hypersensitivity reaction that classically presents with fever, rash, polyarthritis, or poly arthralgias. Damage is caused by formation or deposition of antigen-antibody complexes in vessels or tissues. Deposition of immune complexes causes complement activation and/or recruitment of neutrophils by interaction of immune complexes with Fc immunoglobulin G receptors. The condition was first recognized as an entity in the early 1900s in patients who had received heterologous antisera, which was historically used to treat infectious diseases. The symptoms typically occur one to two weeks after exposure to an offending agent and resolve within several weeks of discontinuation [1].

Background: Seasickness is thought to result from conflicting inputs from the vestibular, visual and somatosensory systems. The otolithic organs, which are responsible for the sensation of linear acceleration and tilt, are important in the pathogenesis of seasickness. Vestibular evoked myogenic potentials test is an objective evaluation of saccular function.

Objective: To examine whether saccular function is related to the pathogenesis of seasickness.

Methods: VEMP1 was performed in 10 subjects susceptible to seasickness and in 14 non-susceptible subjects.

Results: Bilateral VEMP responses were obtained in 7 (50%) of the non-susceptible subjects and 1 (10%) of the susceptible subjects. No differences were found between the groups in P13 and N23 wave latencies, amplitudes, N13-P23 inter-peak latencies, and peak-to-peak asymmetry ratios. More subjects in the susceptible group had asymmetry ratios > 35%.   

Conclusions: The attenuated saccular response might be explained in the context of the neural-mismatch theory and/or the subjective vertical theory, as reflecting an adaptation effort to sea conditions. A larger study is necessary to determine whether a statistically significant difference in VEMP responses exists between seasickness-susceptible and non-susceptible subjects.
 

Rembrandt van Rijn (1606–1669) left behind the largest collection of self-portraits in the history of art. These portraits were painted over a period of 41 years, using a realistic technique. To evaluate Rembrandt's aging process we studied 25 uncontested Rembrandt oil self-portraits by means of objective and descriptive techniques. By measuring brow position changes through the years, we demonstrated that brow descent started in the second half of the third decade and began to level out in the fourth decade. Based on Rembrandts' aging physiognomy, from age 22 to 63, we believe that Rembrandt did not suffer from temporal arteritis, hypothyroidism, rosacea, or rhynophima and that no other facial signs of systemic diseases are evident, contrary to the opinions expressed by other medical professionals. We suggest that Rembrandt suffered from melancholia or mild depression, and propose the possibility of chronic lead poisoning as a theoretical illness that he might have had.

Background: Ventilator-dependent patients represent an increasing clinical, logistic and economic burden.  An alternative solution might be monitored home care with high-tech ventilatory support systems. 

Objectives: To explore the implications of such home-care management, such as its impact on quality of life and its cost-effectiveness, and to assess the practical feasibility of this mode of home care in Israel.

Methods: We surveyed 25 partly or fully home-ventilated patients (17 males and 8 females), average age 37.6 years (range 1–72), who were treated through a home-care provider during a 2 year period.

Results: Most patients (n=18) had a neuromuscular respiratory disorder.  The average hospital stay of these patients prior to entry into the home-care program was 181.2 days/per patient.  The average home-care duration was 404.9 days/per patient (range 60–971) with a low hospitalization rate of 3.3 ± 6.5 days/per patient.  The monthly expenditure for home care of these patients was one-third that of the hospital stay cost ($3,546.9 vs. $11,000, per patient respectively).  The patients reported better quality of life in the home-care environment, as assessed by the Sickness Impact Profile questionnaire. 

Conclusions: Home ventilation of patients in Israel by home-care providers is a practical and attractive treatment modality in terms of economic benefits and quality of life.