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Johnston, Smith L.

Publications and source records attributed to Johnston, Smith L..

Flight Crew Health Stabilization Program

This document establishes the policy and procedures for the HSP and is authorized through the Director, Johnson Space Center (JSC). This document delineates the medical operations requirements for the HSP. The HSP goals are accomplished through an awareness campaign and procedures such as limiting access to flight crewmembers, medical screening, and controlling flight crewmember activities. NASA's Human Space Flight Program uses strategic risk mitigation to achieve mission success while protecting crew health and safety. Infectious diseases can compromise crew health and mission success, especially in the immediate preflight period. The primary purpose of the Flight Crew Health Stabilization Program (HSP) is to mitigate the risk of occurrence of infectious disease among astronaut flight crews in the immediate preflight period. Infectious diseases are contracted through direct person-to-person contact, and through contact with infectious material in the environment. The HSP establishes several controls to minimize crew exposure to infectious agents. The HSP provides a quarantine environment for the crew that minimizes contact with potentially infectious material. The HSP also limits the number of individuals who come in close contact with the crew. The infection-carrying potential of these primary contacts (PCs) is minimized by educating them in ways to avoid infections and avoiding contact with the crew if they are or may be sick. The transmission of some infectious diseases can be greatly curtailed by vaccinations. PCs are strongly encouraged to maintain updated vaccinations.

Johnston, Smith L.

Cardiac Atrophy and Diastolic Dysfunction During and After Long Duration Spaceflight: Functional Consequences for Orthostatic Intolerance, Exercise Capability and Risk for Cardiac Arrhythmias

Cardiac Atrophy and Diastolic Dysfunction During and After Long Duration Spaceflight: Functional Consequences for Orthostatic Intolerance, Exercise Capability and Risk for Cardiac Arrhythmias (Integrated Cardiovascular) will quantify the extent of long-duration space flightassociated cardiac atrophy (deterioration) on the International Space Station crewmembers.

Levine, Benjamin D.

Cardiopulmonary Resuscitation in Microgravity: Efficacy in the Swine During Parabolic Flight

INTRODUCTION: The International Space Station will need to be as capable as possible in providing Advanced Cardiac Life Support (ACLS) and cardiopulmonary resuscitation (CPR). Previous studies with manikins in parabolic microgravity (0 G) have shown that delivering CPR in microgravity is difficult. End tidal carbon dioxide (PetCO2) has been previously shown to be an effective non-invasive tool for estimating cardiac output during cardiopulmonary resuscitation. Animal models have shown that this diagnostic adjunct can be used as a predictor of survival when PetCO2 values are maintained above 25% of pre-arrest values. METHODS: Eleven anesthetized Yorkshire swine were flown in microgravity during parabolic flight. Physiologic parameters, including PetCO2, were monitored. Standard ACLS protocols were used to resuscitate these models after chemical induction of cardiac arrest. Chest compressions were administered using conventional body positioning with waist restraint and unconventional vertical-inverted body positioning. RESULTS: PetCO2 values were maintained above 25% of both 1-G and O-G pre-arrest values in the microgravity environment (33% +/- 3 and 41 +/- 3). No significant difference between 1-G CPR and O-G CPR was found in these animal models. Effective CPR was delivered in both body positions although conventional body positioning was found to be quickly fatiguing as compared with the vertical-inverted. CONCLUSIONS: Cardiopulmonary resuscitation can be effectively administered in microgravity (0 G). Validation of this model has demonstrated that PetCO2 levels were maintained above a level previously reported to be predictive of survival. The unconventional vertical-inverted position provided effective CPR and was less fatiguing as compared with the conventional body position with waist restraints.

Weightlessness

Efficacy of Cardiopulmonary Resuscitation in the Microgravity Environment

End tidal carbon dioxide (EtCO 2) has been previously shown to be an effective non-invasive tool for estimating cardiac output during cardiopulmonary resuscitation (CPR). Animal models have shown that this diagnostic adjunct can be used as a predictor of survival when EtCO 2 values are maintained above 25% of prearrest values.

Johnston, Smith L.