A comparison of high vs standard tidal volumes in ventilator weaning for individuals with sub-acute spinal cord injuries: a site-specific randomized clinical trial.

STUDY DESIGN: Prospective, randomized, controlled parallel group trial with single-blinded data analysis. OBJECTIVES: To determine the safety and efficacy of higher (20 ml kg(-1) ideal body weight (IBW)) vs standard (10 ml kg(-1) IBW) tidal volumes (Vt) for patients with sub-acute traumatic tetraplegia during ventilator weaning using a 14-day (minimum) weaning protocol. SETTING: United States regional spinal cord injury treatment center. METHODS: Thirty-three ventilator requiring inpatients were randomized to either the higher (Group 1) or the standard (Group 2) Vt protocol. Initially, all patients were ventilated at 10 ml kg(-1) IBW Vt and 5 cm H(2)O [corrected] of PEEP for 72 h. For Group 1, Vt was raised 100 ml kg(-1) until reaching target Vt of 20 ml kg(-1) IBW. Group 2 was maintained at Vt of 10 ml kg(-1) IBW. Plateau pressures were kept at or below 30 cm H(2)O. [corrected]. Safety outcomes included incidence of adverse events. RESULTS: Because of smaller than expected enrollment, evaluation of efficacy was not possible. Therefore, we report the safety outcomes of 33 study participants. The 16 patients in Group 1 and 17 patients in Group 2 were demographically similar at baseline, except for age. The average age was 39.3 years in Group 1 and 27.2 years in Group 2, (P=0.002). There was no difference in median days to wean: 14.5 days in Group 1 and 14 days in Group 2. The incidence of adverse pulmonary events was similar between groups. CONCLUSION: Higher tidal volumes can be safely utilized during weaning of patients with tetraplegia from mechanical ventilation using a 14-day weaning protocol.

Are missionaries at risk for AIDS? Evaluation for HIV antibodies in 3,207 protestant missionaries.

Serum specimens (n = 6,045) obtained from 3,207 Protestant missionaries serving in 57 countries, including 28 African nations, between 1967 and 1984 were assayed for antibodies to the human immunodeficiency virus (HIV) by enzyme-linked immunosorbent assay (ELISA) screening and Western blot confirmatory testing. Seventy sera (1.2%) from 51 missionaries (1.6%) were ELISA positive; however, on Western blot confirmatory testing none was diagnostic of HIV infection. Twenty-two (43%) of the Western blot tests were read as indeterminate, with band p17 occurring with the greatest frequency (57%), followed by p24 (23%), either alone or in combination. The significance of these equivocal results is unclear, but they do not appear to be a consequence of exposure to either HIV or the related retrovirus HTLV-I. Based on this seroprevalence survey, we conclude that missionary staff and their families were not at high risk of HIV infection between 1967 and 1984, even when serving in regions of high HIV endemicity.

Missionary health: the great omission.

North American mission boards were surveyed to identify and prioritize missionary medical problems and determine initiatives for improving health. Malaria was the most common nontrivial medical complaint, and viral hepatitis the most serious. Nevertheless, only 72 percent of boards recommend malaria prophylaxis, 57 percent ascribe to regular immune globulin use, and 31 percent advocate hepatitis B immunization. Sub-Saharan Africa was considered the region of the world where missionary health was most in peril. Besides strategies to minimize the risks of malaria and hepatitis, recommendations for improving missionary health include greater use of rabies and typhoid vaccines; increased attention to mental health concerns and accident prevention, particularly seat belt use; increased health education regarding both clinical issues and public health principles; improved scheduling for relaxation and family time; and greater availability of comprehensive health services before departing, while abroad, and upon returning from an overseas assignment.

The prevalence of serological markers to hepatitis A and hepatitis B in drug abuse personnel.

A seroepidemiologic survey was conducted in 25 clinical and 31 nonclinical personnel engaged in substance abuse research and treatment. The antibody to hepatitis A virus (anti-HAV) was identified in 16 percent of the clinical employees and 39 percent of the nonclinical personnel, for a total prevalence of 29 percent. The prevalence of anti-HAV was age related, and the overall frequency was not greater than expected attack rates. Hepatitis B virus (HBV) markers were present in 16 percent of the clinical personnel tested but in only 3 percent of nonclinical personnel, for a total prevalence of 9 percent among the two groups. The nonclinical risk did not exceed the background prevalence of the disease, but the risk for clinical employees was three to five times greater. This risk appeared to be associated with exposure to blood and other potentially infectious body fluids; however, in no case could an employee with HBV markers recall a percutaneous injury, and covert means of transmission could not be excluded. Only one case (20 percent) of HBV infection manifested clinical symptomatology. Even though proper environmental safety measures may decrease the incidence of HBV infection in at-risk groups, some health care workers and researchers in the field of substance abuse may be at sufficiently increased risk of HBV infection to warrant immunization with hepatitis B vaccine.

Travelers' diarrhea. Controversy and consensus.

In view of all the controversy surrounding travelers' diarrhea, how should patients be counseled regarding its prevention and treatment? First, all patients should be instructed on the importance of eating and drinking only safe food and water and on methods of dietary manipulation and oral rehydration therapy. The travelers listed in table 4, as well as short-term visitors to Mexico, may be candidates for prophylactic medication unless such treatment is contraindicated. All patients can be offered an antimotility agent for discriminant use as discussed, and a prescription for trimethoprim-sulfamethoxazole is generally a good idea in the event of a severe bout of illness during travel. A traveler can go overboard in an attempt to avoid diarrheal illness. Such overconcern can detract from the enjoyment of travel and limit the spectrum of activities and cuisine. One report noted that diarrhea seemed to occur more frequently the more a traveler tried to elude it! This could well set the stage for the biggest controversy of all.

Precautionary measures for the wise traveler. Some common hazards.

Several risks can be posed by travel, even when the stay is not protracted nor the destination exotic. Air travelers should consider the potential problems associated with decreased cabin pressure, hypoxia, and circadian dysrhythmia, problems that can contraindicate flying for some. Motion sickness can affect those traveling by air, sea, or land; medications are available to combat the symptoms, and several other remedies such as changing visual stimuli are also worth trying. Persons staying in hotels, particularly high rises, should review several general guidelines for defensive action in case of fire and should become familiar with the physical layout and escape routes of the building in which they are staying.

The little black bag. Medical travel kits for patient and physician.

The medical supplies appropriate for travel will quite naturally depend on the individual and on the nature, scope, and duration of the trip being planned. A basic kit containing nonmedicinal supplies, nonprescription drugs, and prescription medications can be a starting point in planning for both lay and physician travelers, however. Although medical responsibility for assisting in emergency situations during travels as well as liability differ from location to location, in general the physician should not hesitate to give aid in perceived situations of need.

Immunization. Around the world in 80 shots.

Physicians counseling patients who are planning major travels should make sure that baseline immunizations (diphtheria-tetanus-pertussis, polio, measles, rubella) and any necessary boosters are current. In addition, several other immunizations may be warranted (yellow fever, typhoid, and cholera), depending on destination(s) and itinerary, and prophylaxis for malaria may be advisable. As worldwide requirements for immunization do change, the physician should verify current requirements before planning an immunization schedule for a particular patient.

Before the patient packs.

Various medical conditions--cardiovascular and pulmonary problems, thrombosis, diabetes, and others--can present special risks and/or problems in travel. These should be discussed as part of a thorough predeparture evaluation with affected patients who are planning overseas travel. In addition, certain travelers may require medical follow-up on their return. Various travel medicine resource organizations, booklets, and books should be made known to all travelers.