Simulator sickness among helicopter pilots: Incidence, threshold and severity using the SSQ.

BACKGROUND: Flight simulators have an essential role in aircrew training. Occasionally, symptoms of motion sickness, defined as simulator sickness, develop during training sessions. The reported incidence of simulator sickness ranged widely in different studies. OBJECTIVE: The aims of this study were to calculate the incidence of and to define a threshold value for simulator sickness among rotary-wing pilots using the validated Simulator Sickness Questionnaire (SSQ). METHODS: CH-53 and UH-60 helicopter pilots, who trained in helicopter simulators in the Israeli Air Force, were asked to fulfill SSQ. A score of 20 in the SSQ was defined as the threshold for simulator sickness. Simulator sickness incidence and average SSQ were calculated. Correlations between age and simulator training hours to SSQ scores were analyzed. RESULTS: A total of 207 rotary-wing aircrew participated in the study. Simulator sickness was experienced by 51.7% of trainees. The average SSQ score was 32.7. A significant negative correlation was found between age and SSQ score. CONCLUSIONS: Simulator sickness was experienced by more than half of helicopter pilots. A score of 20 in the SSQ was found to be suitable as the threshold for this condition.

Facial and trigeminal nerves neuropathy induced by atmospheric pressure changes: A meta-analysis.

BACKGROUND: Barometric pressure changes during flight or diving may cause facial barotrauma. Neuropathy of the fifth (CN5) or the seventh (CN7) cranial nerves is a rare manifestation of this condition. The aim of this study was to analyze risk factors for baroneuropathies of CN5 and CN7. METHODS: A search of PubMed and Cochrane Library databases was conducted to identify all published cases of CN5 and CN7 neuropathies. Only original case reports and series that documented events of neuropathies associated with the trigeminal nerve or facial nerve while flying, diving, or mountain climbing were included. Assessed variables included sex, medical history, age, setting (flight or diving), atmospheric pressure changes, number of episodes, symptoms, treatment, and recovery. RESULTS: We identified a total of 48 articles described >125 episodes in 67 patients. Mean age was 33.5 ± 12.1 years with a male predominance (76.1 %). Cases were equally distributed between flight and diving (50.7 %, 46.3 %, respectively). CN5 involvement was observed in 77.6 % of patients, with ear pain and facial numbness as the most common symptoms. The latter was correlated with positive otolaryngology medical history. CN7 was involved in 88.1 % of patients. Flying, as opposed to diving was correlated with spontaneous resolution of symptoms (86.7 % vs. 42.3 % of cases resolved spontaneously, respectively, p = 0.001). CONCLUSIONS: Flight is an equal risk factor to diving with respect to CN5 and CN7 barotrauma. Involvement of CN7 was observed in most cases, but possibly due to report-bias. Positive medical history is a risk factor for facial numbness.

Cognitive performance of air personnel following sleep deprivation.

Air forces have developed several methods for reducing fatigue-related accidents. In the Israeli Air Force, the "Dead Tired" workshop was developed with the purpose of presenting aircrew with their objective performance under sleep deprivation conditions. The aim of this study was to examine the cognitive abilities of both aircrew and unmanned aerial vehicle operators, both objectively and subjectively. All Israeli aircrew and unmanned aerial vehicle operators participated in a "Dead Tired" workshop. During the workshop, the participants performed the Psychomotor Vigilance Task, a task that tests their attention abilities, while gathering information on their subjective sleepiness in the form of a Karolinska Sleepiness Scale. Data of 366 participants (25 females), of whom 187 were unmanned aerial vehicle operators and 179 were aircrew, were obtained; and the mean age was 21.8 ± 1.2 years (range 19-26 years). A significant decline in task performance was seen following 20 hr of wakefulness in both unmanned aerial vehicle operators and aircrew (p < 0.001). Unmanned aerial vehicle operators' performance was significantly better throughout the majority of the workshop (p < 0.001). Recovery after the full-night's sleep was seen for unmanned aerial vehicle operators, but not for aircrew (p = 0.008). A high correlation was seen between Psychomotor Vigilance Task performance and Karolinska Sleepiness Scale responses (correlation coefficient = 0.93). Sleep deprivation negatively impacted the performance of both groups of participants. Unmanned aerial vehicle operators were found to be more resilient to the effects of sleep deprivation and were quicker to recover in comparison to aircrew.

Anticholinergic Versus Antihistaminic Treatment for Simulator Sickness Prevention.

Flight simulators have an essential role in aircrew training. Occasionally, symptoms of motion sickness, defined as simulator sickness, develop during these sessions. Preventive methods for motion sickness have been investigated thoroughly; however, only a few studies have examined preventive treatments for simulator sickness. The aim of this study was to examine the efficacy of scopolamine (an anticholinergic drug) compared with cinnarizine (an antihistaminic drug) for helicopter simulator sickness prevention. A validated simulator sickness questionnaire (SSQ) score was used to determine the severity of simulator sickness symptoms in this study. Preliminary SSQ scores and SSQ scores after each sortie were calculated. Each participant was given scopolamine, cinnarizine, or a placebo in a double-blind randomized manner before the first sortie of each training day. Forty-one helicopter pilots participated in the trial. The average age was 30.5 ± 7.1 years. SSQ values significantly improved from an average of 73.30 in the preliminary SSQ questionnaire to an average of 30.92 after 2 hours following the administration of cinnarizine (P = .012, 95%CI 8.071-76.703). Scopolamine was found to be less effective than both cinnarizine and the placebo in the alleviation of simulator sickness symptoms. This study is the first to compare scopolamine with cinnarizine for simulator sickness prevention. Based on the results of this study, we recommend the use of cinnarizine over scopolamine for simulator sickness prevention.

Dental tourism and the risk of barotrauma and barodontalgia.

Background and aim Dental tourism, which reflects the provision of health care services abroad, also includes a travelling component. Air travel after dental intervention may cause barotrauma and barodontalgia. This paper aimed to provide guiding principles regarding the minimal time interval between dental procedures and air travel to prevent these adverse effects.Methods A literature search was performed to reveal information with regards to complications related to flights following dental treatments. There is little research in this area and most of it has been conducted on the military aircrew population, which has different characteristics of flight and personnel than civilian commercial flights.Results The recommended time of flying is one week after most dental intervention and six weeks after a sinus lift procedure. The minimal time required between a procedure and flight is 24 hours after restorative treatment, 24-48 hours after simple extraction, 72 hours after nonsurgical endodontic procedure, surgical extraction, and implant placement, and at least two weeks after sinus lift procedure.Conclusions The provided guidelines may serve as a starting point for the clinician's decision-making. The tailoring of an individual treatment plan to the patient should take into consideration the patient's condition, dental procedure, complications and flight characteristics. Further research based on commercial flights is needed to formulate more accurate guidelines for the civilian population.

Mitigating Risks of Altitude Chamber Training.

INTRODUCTION: Altitude chambers are used for training aircrews in a hypobaric hypoxic environment to better prepare them for pressurization and oxygen malfunction incidents during flights. However, adverse effects may occur during training sessions, with decompression sickness (DCS) being a major concern. The aim of this study was to examine the risks of different adverse effects during altitude chamber trainings (ACT) in the Israeli Air Force (IAF) facility and to compare them to other training facilities.METHODS: We retrospectively reviewed the records of 1627 individuals in the IAF who were trained in the altitude chamber between 2015 and 2019. Data regarding adverse effects and training safety were extracted. Literature review of altitude chamber trainings was performed and adverse effects rates were compared.RESULTS: There were a total of 91 adverse effects cases in the IAF during the study period. The overall risk rate for an adverse effect was 5.59%. The most common adverse effect was middle ear and sinus barotrauma (69.3% of adverse effects cases), followed by breathing problems (14.3%) and DCS cases (9.9%).CONCLUSIONS: Mitigating the risk for DCS should be major concern during ACT. We recommend setting a standard protocol for an ACT which includes a 45-min preoxygenation period, a maximal ascent rate of 3000 ft · min-1 (914 m · min-1), and setting a maximum altitude of 25,000 ft (7620 m) for fixed-wing trainees.Nakdimon I, Ben-Ari O. Mitigating risks of altitude chamber training. Aerosp Med Hum Perform. 2022; 93(11):811-815.

Injuries associated with the use of ejection seats: a systematic review, meta-analysis and the experience of the Israeli Air Force, 1990-2019.

INTRODUCTION: All modern military jet aircraft are equipped with rocket-assisted ejection systems. Jet aircraft operate in the majority of the conflict regions throughout the world, and in nearly all modern countries during peacetime. Civilian and military emergency services may be called upon to treat aircrews that have ejected and should be familiar with the common injury patterns associated with aircraft ejection. METHODS: A systematic review and meta-analysis of the literature were undertaken using the preferred reporting for systematic reviews and meta-analyses (PRISMA) methodology. Peer-reviewed journal and conference papers published between 1 January 1971 and 15 June 2019 were included. Our primary outcomes of interest were mortality and major injury rates. The I2 test was used to assess heterogeneity among the included studies, and data were pooled under random effects models. In addition, all ejection cases in the Israeli Air Force (IAF) between 1990 and 2019 were studied. The data were manually extracted from the accident records and the electronic medical records system. RESULTS: We identified 14 studies that included 1710 aircrew ejections. Heterogeneity was high (I2>75%). Pooled mean mortality and major injury rates were 10.5% (95% CI 6.8-14.8%) and 29.8% (95% CI 20.1-40.6%), respectively. The major injuries included spinal fractures (61.6%), extremity trauma (27.3%), and head trauma (8.9%). During the IAF study period, a total of 37 aircrew ejected from 26 IAF aircraft. The fatality rate was 5.4% and 18.9% suffered major injuries. CONCLUSIONS: Although ejection is lifesaving, it is associated with unique injury patterns that should be addressed during clinical evaluation. Because of their high prevalence, spinal precautions are paramount until spinal injury can be ruled out, generally by advanced imaging. Looking forward, injury patterns will continue to evolve in parallel with improving ejection seat systems.

Success Rates at an Air Force Pilot Academy and Its Relation to Methylphenidate Use.

BACKGROUND: Attention deficit hyperactivity disorder (ADHD) is a chronic neurological disorder characterized by persistent patterns of inattention, impulsivity, and hyperactivity. The most common treatment for this disorder is methylphenidate, which is a disqualifying medication for flight. Candidates with previous use of methylphenidate are not necessarily disqualified from the Israeli Air Force (IAF) flight academy.METHODS: Flight cadets from 12 consecutive flight courses who have used methylphenidate at least once in the past were identified according to their medical records. The graduation ratio of cadets with previous use of methylphenidate was compared with that of the rest of the cadets. A comparison was also made with regard to the causes of disqualification from the flight course. Statistical significance was assessed using the Fischer Test.RESULTS: Among the 90 flight cadets who have used methylphenidate, only 2 (2.2%) successfully graduated from the IAF flight academy. Among the 2983 flight cadets who have no history of methylphenidate use, 461 (15.4%) successfully graduated. We found no significant differences in the disqualification causes between the two groups.CONCLUSION: The IAF flight academy graduation rate was meaningfully and significantly lower among cadets who reported previous use of methylphenidate. The study design, however, limits the inference of causal relationship.Sarfati S, Nakdimon I, Tsodyks J, Assa A, Gordon B. Success rates at an air force pilot academy and its relation to methylphenidate use. Aerosp Med Hum Perform. 2019; 90(9):788-791.

Barodontalgia Among Aircrew and Divers.

BACKGROUND: Barodontalgia, barometric pressure-induced dental pain, may jeopardize diving/flight safety. The aim of this systematic review was to investigate the rate of barodontalgia among military and civilian divers and aircrews based on previous reports.METHODS: We analyzed the data of 4894 aircrew/divers reported in the literature. Barodontalgia rates (flight vs. diving, military vs. civilian, pressurized vs. non-pressurized aircrafts) were analyzed. The Chi-squared test was used to compare between groups.RESULTS: Of the 4894 individuals, 402 (8.2%) suffered from barodontalgia. Divers (9.8%) were more vulnerable than aircrews (5.8%). Barodontalgia experience rate was 5.4% and 6.5% in military and civilian aircrews, respectively, and 7.3% and 12.8% in military and civilian scuba divers, respectively. Barodontalgia was more common among aircrews of pressurized than non-pressurized aircrafts (7.3% vs. 3.2%, respectively).DISCUSSION: The greater amplitude of barometric pressure changes explains the higher rate of barodontalgia in divers than aircrew. The higher rate during pressurized flights is possibly because intracabin pressure in the pressurized cabin is still routinely higher than in nonpressurized aircrafts. Improved oral care and mandatory annual dental checkups may be the reason for the significantly lower rate of barodontalgia experienced among military aircrews and divers compared to their civilian counterparts. These results emphasize the essential role of atmospheric pressure change in the generation of pain during flight or diving and the importance of proper dental care.Nakdimon I, Zadik Y. Barodontalgia among aircrew and divers. Aerosp Med Hum Perform. 2019; 90(2):128-131.

Incidence and Features of Barodontalgia Among Military Divers.

OBJECTIVE: Divers are vulnerable to barodontalgia (atmospheric pressure change related dental pain), which may jeopardize diving safety and mission completion. Our aim was to investigate the experience of barodontalgia among western military divers. METHODS: French Armed Forces diving personnel were asked to answer a structured questionnaire including questions regarding their oral health, diving and career features, and barodontalgia while diving. For analysis, the participants were divided into commando/clearance divers (Group A) and ship divers (Group B). RESULTS: All the requested 1389 divers agreed to participate in the study (100%) and 1317 divers (94.8%) who fully completed the questionnaire were included in the analysis. Of these 1317 individuals, 96 (7.3%) suffered from at least 1 episode of barodontalgia while diving, with a total of 119 episodes of barodontalgia. Barodontalgia was more frequent in the upper (62.2%) than the lower dentition (37.8%) (OR = 2.7; 95% CI, 1.6-4.5) and appeared more common during descent (77.3%) than ascent (22.7%) (OR = 11.6; 95% CI, 6.3-31.3). Barodontalgia experience was higher in divers who have an examination less than once per year (14.5%) in comparison to divers who usually have a dental examination once a year or more (6.3%) (OR = 2.5; 95% CI, 1.5-4.2). DISCUSSION: Barodontalgia mostly appeared in the maxilla and during descent; therefore, a great role for barosinusitis in the etiology of oral pain while diving may be suggested. The infrequent experience of barodontalgia in divers who routinely visit the dentist once a year or more suggests that the risk of barodontalgia might decrease with the maintenance of a good oral status.

International medical leadership, collaboration and communication.

BACKGROUND: International social networking is eminent in medical practice, mainly in sharing knowledge and mutual inspiring and in social and professional bonding. Since 2006, the International Medical Course is taking place in Commander Branch at the Military Medicine Academy of the Medical Corps, Israeli Defense Forces; in which medical officers from other military forces are participating along with Israeli officers. One of the course's objectives is international networking. The purpose of this study was to assess the level of networking in the International Medical Course compared to others means of networking, and to examine which components in the course are the most important in networking formation. METHODS: Questionnaires were e-mailed to the course participants. Demographic data and data regarding the networking possibilities in the international medical course was collected. RESULTS: The answers of 35 participants (17 Majors, 12 Lieutenant-Colonels, and 6 Colonels; mean age of 44.1 years) were included in this study. Response rate was 42%. Of the participants, 24 were Israelis and 11 from other military forces. Most of the responders (88.6%) reported the course is a major networking tool, with no influence of age, sex, rank, education profession or origin. Networking potential among participants from the same origin country was significantly higher in Israeli officers in comparison to officers from other countries (p = 0.001). Clinical practice and research purposes were the reason for communication in one fifth of the participants. CONCLUSIONS: The International Medical Course fulfils its purpose in forming international military medical networking.

Dental Barotrauma in French Military Divers: Results of the POP Study.

OBJECTIVE: The aim of the POP (odontological problems among divers) study was to assess dental barotrauma among French military divers exposed to an underwater environment. METHODS: A questionnaire on dental barotrauma was completed by the divers who presented at the SMHEP (Centre for Hyperbaric Medicine and Diving Expertise) for their quadrennial medical exam from March 2011 to July 2014. RESULTS: There were 1317 questionnaires completed, representing 60.6% of all French military divers. A total of 5.3% of divers had a dental barotrauma (70/1317), mainly fracture and/or loss of dental restoration. Dental barotrauma disrupted diving in 34.3% of cases. A total of 76.4% of divers were informed by a military physician of the importance of maintaining good oral health and 88.5% of divers consult their dentist at least once a year. Of the participants, 82.5% made their dentist aware they are divers, but only 4.9% of the dental practitioners advised their patient not to dive after some types of dental treatments and 12.8% indicated that, as divers, they need adapted dental treatments. CONCLUSIONS: Dental barotrauma was experienced by 1 in 19 military divers. Nevertheless, a contradiction exists between the frequency of dental barotraumas and the rigorous medical and dental follow-up of military divers. We note that there is inadequate dental management of divers when dental issues are identified. To avoid this unsatisfactory situation, "diving dentistry" should be taught to military and civilian dentists and physicians to make them aware of the potential dental complications and preventive measures associated with operating in a subaquatic environment.

Back symptoms in aviators flying different aircraft.

INTRODUCTION: Back pain is a common complaint among military aviators of various aircraft. We attempted to define the epidemiologic characteristics of this complaint in military aviators of the Israeli Air Force. METHODS: Aviators of various aircraft (fighter, attack helicopter, utility helicopter, and transport and cargo) completed 566 questionnaires. The questionnaires included various demographic variables as well as questions specifically addressing type of aircraft, location, and severity of pain. Questionnaires were analyzed according to aircraft type, weekly and total number of flight hours. RESULTS: Back pain was significantly more common among utility and attack helicopter pilots. Compared with only 64.02% of fighter pilots, 89.38% of utility and 74.55% of attack helicopter pilots reported some degree of back pain. Cervical region pain was more common among fighter pilots (47.2%) and utility helicopter pilots (47.3%) compared with attack helicopter (36.4%) and transport (22.3%) pilots. Cervical region pain of moderate-severe degree was more common among utility helicopter pilots (7.1%). Mid and low back pain at all degrees of severity were more common among helicopter pilots. A significant proportion of subjects suffered from pain in multiple regions, particularly among utility helicopter pilots (32.74%). Severity of pain was graded higher in all three regions (cervical, mid, and lower back) in utility helicopter pilots. CONCLUSIONS: Utility helicopter pilots have more prevalent and more severe back pain than pilots of other platforms. Yet, it is difficult to make a clear association between type of aircraft and the region of back pain.