RESUMEN
Spontaneous pneumothorax is one cause of aeronautical unfitness in flight personnel, because of the risk of recurrence in flight, making it an issue of flight safety. Specific treatment is required for fighter pilots, pilots flying single-pilot and pilots in professional training: surgical synthesis via video-thoracoscopy is obligatory from the first episode. Considering the exposure to an accumulation of aeronautical factors that are likely to encourage pneumothorax recurrence in flight, it is apical pleurectomy together with abrasion of the remaining pleura and resection of bullae/blebs that is required for fighter pilots to allow them to recover aeronautical fitness unrestrictedly. For all other categories of flight personnel, treatment is no different from that of the common patient. Knowledge of these treatment specifics is essential, to avoid unnecessary systematic surgical indication for all flight personnel, or jeopardise professional fitness in some of them due to inappropriate treatment.
Asunto(s)
Aviación , Enfermedades Profesionales/cirugía , Neumotórax/cirugía , Humanos , Personal Militar , Enfermedades Profesionales/prevención & control , Aptitud Física , Pleura/cirugía , Neumotórax/prevención & control , Recurrencia , Factores de Riesgo , Seguridad , ToracoscopíaRESUMEN
Aerobatics is an aerial sport which has many physiological constraints, principally cardiovascular, with a risk if not adapted of sudden mid-air incapacity which could jeopardise aviation safety, and thus justifies the selection and surveillance of pilots. The aeronautical constraints during flight are multiple, related to the environment traversed, how the aircraft functions and its movements. Those which cause accelerations (+G in particular) pose the problem of haemodynamic tolerance because they can induce loss of consciousness due to cerebral hypoxia. Tolerance of acceleration varies among individuals; it can be improved with training, certain protective manoeuvres, and is reduced by hypoxia, certain medications, dehydration and heat. Moreover, in aerobatics certain tricks require manoeuvres which reduce this tolerance to +G accelerations. This is the "push-pull" effect (_G acceleration immediately followed by +G acceleration). This leads to a risk of sudden loss of consciousness with a load factor much lower than that which the pilot knows he is capable of tolerating. Besides the haemodynamic effects, the existence of an actual acceleration cardiomyopathy has been suggested but has not been proven in man. Finally, while changes in cardiac rhythm during accelerations are usual and relate to changes in vaso-sympathetic balance, ventricular and supra-ventricular rhythm disturbances are rare and are related to the intensity and duration of the acceleration.
Asunto(s)
Medicina Aeroespacial , Cardiomiopatías/etiología , Hipergravedad/efectos adversos , Deportes , Aeronaves , Deshidratación , Hemodinámica , Humanos , Hipoxia , Fenómenos Físicos , Física , Factores de RiesgoRESUMEN
The electrocardiographic appearances and the significance of right bundle branch block were described at the beginning of the 20th century. Typical appearances include prolongation > 0.12 s of the QRS complex, RR' or rR' or Rr' appearances in V1 and widened S waves in the leads exploring the left ventricle (SI, aVL, V5 and V6). A delay in the appearance of the intrinsic deflection > 0.08 s may also be observed in the right precordial leads and negative T waves with ST depression may be seen in V1 and sometimes in V2. Left axis deviation of the QRS complex greater than - 45 degrees suggests associated left anterior hemiblock. Right axis deviation beyond + 120 degrees is equivocal. The principal differential ECG diagnosis is the Brugada syndrome, a familial arrhythmogenic autosomal dominant cardiomyopathy of variable penetration. This diagnosis is suggested when ECG abnormalities are observed in patients with a personal or family history of sudden death. Right bundle branch block only seems to have haemodynamic consequences in cardiac failure with associated asynchrony of the left ventricle or in certain cases of right ventricular dilatation encountered in congenital heart disease. The prognosis of right bundle branch block in the absence of underlying cardiac disease is good but it may be poor in other cases, particularly coronary artery disease. Moreover, the prognosis of right bundle branch block to complete atrioventricular block is rare in the absence of associated cardiac disease.
Asunto(s)
Bloqueo de Rama/diagnóstico , Bloqueo de Rama/fisiopatología , Electrocardiografía , Bloqueo de Rama/mortalidad , Diagnóstico Diferencial , Humanos , PronósticoRESUMEN
The chloroquine is the mainly and most frequently drug used as antimalaric in the world, in spite of the extension of resistance phenomena. Besides, the chloroquine is also commonly indicated in rheumatology and dermatology as a chronic treatment of some connective tissue disease. The chloroquine has three main cardiovascular effect: membrane stabilizer, direct negative inotropic effect and direct arterial vasodilator. Thus, these cardiovascular iatrogenic effects of the chloroquine are important both through their potential frequency and seriousness. Personal clinical cases and medical review enables to identify the main effects, observed either with prophylactic, or curative, or even toxic dosages. The more often, there are some rhythm and conductance disorders, myocardiopathy, even sometimes vasoplegic shocks. A list of the commercial patent medicine including chloroquine enables to be aware, to prevent and to take into account the cardiovascular risks of a treatment newly set or carried on for long years.
Asunto(s)
Antimaláricos/efectos adversos , Enfermedades Cardiovasculares/inducido químicamente , Cloroquina/efectos adversos , Antimaláricos/farmacología , Sistema Cardiovascular/efectos de los fármacos , Cloroquina/farmacología , HumanosRESUMEN
INTRODUCTION: The efficacy of Dexedrine for sustaining aviator performance despite 64 h of extended wakefulness was investigated. This study was conducted to extend the findings of earlier research that had proven the efficacy of Dexedrine during shorter periods (i.e., 40 h) of sleep deprivation. METHODS: Dexedrine (10 mg) or placebo was given at midnight, 0400, and 0800 hours on two deprivation days in each of two 64-h cycles of continuous wakefulness. Test sessions consisting of simulator flights, electroencephalographic evaluations, mood questionnaires, and cognitive tasks were conducted at 0100, 0500, 0900, 1300, and 1700 hours on both deprivation days. Two nights of recovery sleep separated the first and second 64-h sleep-deprivation cycles. RESULTS: Simulator flight performance was maintained by Dexedrine throughout sleep deprivation. The most benefit occurred at 0500 and 0900 hours (around the circadian trough) on the first deprivation day, but continued throughout 1700 hours (after 58 h awake) on the second day. Dexedrine suppressed slow-wave EEG activity which occurred under placebo after 23 h awake and continued to exert this effect throughout 55 h (and sometimes 59 h) of deprivation. The drug sustained self-perceptions of vigor while reducing fatigue and confusion. Recovery sleep was slightly less restful under Dexedrine. CONCLUSIONS: Dexedrine sustained aviator performance and alertness during periods of extended wakefulness, but its use should be well controlled. Although effective, Dexedrine is no replacement for adequate crew rest management or restful sleep.
Asunto(s)
Medicina Aeroespacial , Estimulantes del Sistema Nervioso Central/farmacología , Dextroanfetamina/farmacología , Personal Militar , Vigilia/efectos de los fármacos , Adulto , Afecto/efectos de los fármacos , Aeronaves , Estimulantes del Sistema Nervioso Central/efectos adversos , Dextroanfetamina/efectos adversos , Método Doble Ciego , Electroencefalografía , Femenino , Humanos , Masculino , Polisomnografía , Privación de Sueño , Factores de TiempoRESUMEN
Female aviators now are able to serve in combat roles, but few studies have addressed potential differences between the ability of males and females to withstand combat stressors. This study examined responses of men and women to one operational stressor, sleep deprivation. Pilots were tested on flight performance and mood during 40-h periods of sustained wakefulness. Baseline and recovery sleep also were examined. Gender produced no operationally-significant effects of flight performance or recovery sleep. Although mood tests showed that women felt less tense and more energetic than men, there were no interactions between sleep deprivation and gender on either flight performance or psychological mood.
Asunto(s)
Medicina Aeroespacial , Afecto/fisiología , Atención/fisiología , Personal Militar , Desempeño Psicomotor/fisiología , Privación de Sueño/fisiología , Adulto , Corteza Cerebral/fisiopatología , Fatiga/fisiopatología , Femenino , Humanos , Masculino , Polisomnografía , Psicofisiología , Factores SexualesRESUMEN
The authors selected articles from those published between 1975 and 1994 that specifically documented psychostimulant abuse in patients determined to be schizophrenic according to recent and relatively uniform diagnostic criteria. These articles indicated that the incidence of psychostimulant abuse in schizophrenics is 2-5 times higher than that of the general public. Additionally, unlike the decline in stimulant use seen in older adults in the general population, high rates of abuse appeared to be maintained in schizophrenics. Although the incidence of abuse in this group was high, comparisons of abuse rates generated by self report with those obtained by urinalysis indicated that the frequency of abuse is being underestimated by 15-21%. Potential factors contributing to stimulant abuse in schizophrenics, including the disease process, and the influence of chronic neuroleptic medication, were evaluated. Results indicated that the incidence of psychostimulant abuse was neither a common property of psychiatric patients, nor exclusive to schizophrenics, but appeared to be related to chronic treatment with neuroleptic drugs. Symptom severity was generally similar in schizophrenic abusers and non-abusers, which also suggested a degree of independence from the disease process. In a majority of the studies surveyed, abuse of stimulants followed disease onset. It was also found that stimulant abuse was associated with marked increases in hospitalization in this patient group, including those known to be neuroleptic medication compliant. Possible explanations for the initiation and maintenance of psychostimulant abuse in schizophrenics are discussed in relation to clinical and preclinical evidence on drug addiction.
Asunto(s)
Psicotrópicos/farmacología , Esquizofrenia/fisiopatología , Trastornos Relacionados con Sustancias , Humanos , Psicología del EsquizofrénicoRESUMEN
Rats with limbic system damage display increases in responsivity to sensory stimulation and changes in the sensitivity to amphetamine, suggesting that their condition may parallel that of human schizophrenia. This experiment examined locomotion and stereotyped behavior in mature, male rats that had received aspirative lesions of the hippocampus, control lesions of the overlying parietal cortex, or were unoperated controls. Locomotion, measured as photocell beam breaks, was recorded during 2- or 3-h test sessions. Behavioral stereotypy was simultaneously rated. Hippocampal lesioned rats exhibited a selective enhancement in locomotion following D-amphetamine (0.0-5.6 mg/kg) when compared to animals in the control groups. Similar results were observed following injections of apomorphine (0.0-0.25 mg/kg), a mixed D1 and D2 agonist. In order to determine if D1 or D2 receptors were involved in this increased locomotion, the D1 agonist SKF 38393 (0.0-15 mg/kg) and the D2 agonist quinpirole (0.0-0.5 mg/kg) were tested alone and in combination. Hippocampal-ablated rats showed significantly increased locomotion only in response to quinpirole, suggesting that these lesion-induced increases were largely mediated by D2 receptors. When both drugs were administered together, SKF 38393 further enhanced the locomotor stimulating effects of quinpirole in hippocampal lesioned rats, indicating a synergistic interaction between D1 and D2 receptors in the modulation of locomotion. These findings provide further evidence of hippocampal modulation of locomotion and suggest that dopaminergic mechanisms in the nucleus accumbens, probably involving changes in receptor sensitivity, are involved. The results are discussed in relation to the functional roles of the nucleus accumbens and in terms of their implications for mental diseases including schizophrenia.
Asunto(s)
Dopaminérgicos/farmacología , Hipocampo/efectos de los fármacos , Actividad Motora/efectos de los fármacos , Receptores de Dopamina D1/efectos de los fármacos , Receptores de Dopamina D2/efectos de los fármacos , Esquizofrenia/inducido químicamente , Psicología del Esquizofrénico , 2,3,4,5-Tetrahidro-7,8-dihidroxi-1-fenil-1H-3-benzazepina/farmacología , Animales , Apomorfina/farmacología , Nivel de Alerta/efectos de los fármacos , Nivel de Alerta/fisiología , Mapeo Encefálico , Dextroanfetamina/farmacología , Modelos Animales de Enfermedad , Relación Dosis-Respuesta a Droga , Ergolinas/farmacología , Hipocampo/fisiopatología , Masculino , Actividad Motora/fisiología , Quinpirol , Ratas , Receptores de Dopamina D1/fisiología , Receptores de Dopamina D2/fisiología , Esquizofrenia/fisiopatología , Conducta Estereotipada/efectos de los fármacos , Conducta Estereotipada/fisiologíaRESUMEN
This experiment investigated the possibility that rats maintained on chronic haloperidol treatment would show increased behavioral responsiveness to cocaine, similar to that observed in human stimulant abusers who are chronically treated with neuroleptics. Thus, the effects on locomotion and stereotyped behavior of intermittent injections of cocaine were investigated in female rats receiving chronic haloperidol treatment. Daily injections of haloperidol (0.2 mg/kg, IP) or vehicle were administered for 6, 12 or 18 days prior to the start of testing with cocaine and were then continued throughout cocaine testing. All rats received four doses of cocaine (0.0, 3.0, 7.5, or 15.0 mg/kg, IP) in random order with an intervening vehicle day between successive drug days. The four dose sequence of cocaine was repeated a total of four times. Initial cocaine administration produced dose dependent increases in locomotion and stereotyped behavior. When the sequence of cocaine doses was repeated, differences among treatment groups emerged. Groups treated with haloperidol exhibited heightened locomotion in response to cocaine and with repeated injections, showed a higher rate of behavioral sensitization than control animals. These differences in the behavioral response to cocaine were maintained for at least 2 months following termination of daily haloperidol treatment. In order to examine the mechanisms underlying this heightened responsiveness to cocaine, apomorphine-induced locomotion (dose range, 0-250 micrograms/kg, SC) was determined. Regardless of dose, rats treated with haloperidol showed different temporal patterns of locomotion in response to apomorphine suggesting that the increased response to cocaine was related to changes in dopaminergic receptor sensitivity.
Asunto(s)
Conducta Animal/efectos de los fármacos , Cocaína , Haloperidol/farmacología , Trastornos Relacionados con Sustancias/psicología , Animales , Modelos Animales de Enfermedad , Relación Dosis-Respuesta a Droga , Interacciones Farmacológicas , Femenino , Actividad Motora/efectos de los fármacos , Ratas , Receptores Presinapticos/efectos de los fármacos , Conducta Estereotipada/efectos de los fármacosRESUMEN
It was recently reported by Buhot et al. that presession cholinergic disruption with scopolamine decreases time spent in proximity to novel objects while increasing locomotor behavior. Male Long-Evans rats (Rattus norvegicus, 80 days old) were given low-light access to an arena containing objects but were not forced to remain in the arena. On day 1, each subject was injected with saline (SAL). This session was used for familiarization with the apparatus and procedure. On days 2 and 3, four groups were given saline (SAL) or scopolamine (SCO, 1 mg/kg or 0.25 mg/kg), resulting in SAL-SAL, SAL-SCO, SCO-SAL, and SCO-SCO groups. Videotapes of these sessions were scored according to a standard protocol that allows separate quantification of locomotion, general activity, and object interaction behaviors. Scopolamine suppressed object investigation (both gross contact measures and indices of interaction character) whenever present. In contrast to Buhot et al. (using a forced-exploration situation), in this free-exploration context SCO also suppressed locomotor behavior. This study supports the conclusion that anticholinergics impair information gathering instead of affecting memory directly, which calls into question memory-related explanations of cholinergic treatments.