Accuracy and precision of buccal pulse oximetry.

OBJECTIVE: We sought to describe the accuracy and precision of buccal pulse oximetry (SbpO(2)) compared with arterial oxygen saturation (SaO(2)) and pulse oximetry (SpO(2)) in healthy adults at normoxemia and under 3 induced hypoxemic conditions. METHODS: In this prospective, correlational study, SbpO(2), SaO(2), and SpO(2) values were recorded at normoxemia and at three hypoxemic conditions (SpO(2)=90%, 80%, and 70%) for 53 healthy, nonsmoking adults who were without cardiac or pulmonary disease, baseline hypoxemia, peripheral edema, dyshemoglobinemia, and fever. Bland-Altman analyses were used to assess agreement and precision between SbpO(2) and SaO(2) measures and between SbpO(2) and SpO(2) measures. Data were adjusted to account for a lag time between buccal and finger sites. RESULTS: When comparing SbpO(2) and SaO(2) values, mean differences of -1.8%, .3%, 2.4%, and 2.6% were evident at the normoxemia, 90%, 80%, and 70% levels, respectively. When comparing SbpO(2) and SpO(2) values, the mean differences were -1.4%, .1%, 3.3%, and 4.7% at the normoxemia, 90%, 80%, and 70% levels, respectively. The SbpO(2) and SaO(2) values met a priori precision criteria (1.6%; 95% confidence limit, -4.9% to 1.3%) at normoxemia. The SbpO(2) and SpO(2) values met precision criteria at normoxemia (1.5%; 95% confidence limit, -4.4% to 1.5%) and 90% (1.9%; 95% confidence limit, -3.6% to 3.8%) conditions, but exceeded precision criteria at the other tested conditions. On average, SpO(2) lagged 21 seconds behind SbpO(2). CONCLUSION: Buccal oximetry is an inaccurate and imprecise method of assessing SpO(2) when oxygen saturation is <90%. The divergence between SbpO(2) and both SaO(2) or SpO(2) values increased as hypoxemia worsened. The buccal method overestimated oxygen saturation in proportion to the degree of hypoxemia. Such overestimates may lead nurses to conclude falsely that a patient's arterial oxygen saturation is acceptable when further assessment or intervention is warranted.

Military nursing research: translation to disaster response and day-to-day critical care nursing.

Where to begin? How do you identify nursing care requirements for military operations, disaster, and humanitarian response, and how do you modify care under these unique conditions? This article presents a framework for identifying areas of critical care nursing that are performed on a day-to-day basis that may also be provided during a contingency operation, and discusses how that care may be changed by the austere conditions associated with a contingency response. Examples from various disasters, military operations, and military nursing research are used to illustrate the use of this framework. Examples are presented of how the results of this military nursing research inform disaster nursing and day-to-day critical care nursing practice.

Comparison of three strategies for preventing hypothermia in critically injured casualties during aeromedical evacuation.

Critically injured patients are at risk for hypothermia. This study determined the efficacy of three hypothermia prevention strategies: the ChillBuster warming blanket, ChillBuster with a reflective blanket, and two wool blankets. A quasi-experimental design was used to compare changes in core temperature. Following resuscitation from hypovolemic shock, 20 swine were assigned to one of the three interventions, placed in an environmental chamber set to reproduce in-flight conditions onboard a military cargo aircraft (50 degrees F/airspeed 0.2 m/s), and monitored for 6 hours. A repeated measures analysis of variance and least-squared difference post hoc were performed. The ChillBuster/reflective blanket group was significantly warmer than the ChillBuster only group and the wool blanket group (p < 0.01). After 6 hours of cold exposure, the ChillBuster/reflective blanket group remained warm while the ChillBuster only and wool blanket groups developed mild hypothermia. Combined use of a warming blanket and reflective blanket was effective in preventing hypothermia over 6 hours and is feasible in a deployed military environment.

Efficacy of the blizzard blanket or blizzard blanket plus thermal angel in preventing hypothermia in a hemorrhagic shock victim (Sus scrofa) under operational conditions.

The prevention of hypothermia in military casualties under field conditions is challenging. The efficacy of a baffled reflective Blanket (Blizzard Blanket), a portable intravenous fluid warmer (Thermal Angel), and wool Blankets (control) in preventing hypothermia was tested under military field conditions in a swine hemorrhagic shock model. Fifteen pigs were bled at 10 degrees C. After 45 minutes, Hextend was administered (groups 1 and 3, at 10 degrees C; group 2, via Thermal Angel); groups 2 and 3 were encircled with a Blizzard Blanket. After 120 minutes, the pigs were moved to 21 degrees C to simulate a field hospital; group 1 was covered with Blankets. Blood was administered (groups 1 and 3, at 4 degrees C; group 2, via Thermal Angel) with 180 minutes of monitoring. The core temperature was <35 degrees C in five of five control pigs, four of five Blizzard-only pigs, and one of five Thermal Angel plus Blizzard Blanket pigs. The Blizzard Blanket limited but did not prevent hypothermia. The Thermal Angel plus Blizzard Blanket combination prevented hypothermia. The Thermal Angel is useful for bolus administration when electricity is limited; its military field use is constrained by battery weight and battery life.

Critical care nursing expertise during air transport.

The purpose of this study was to describe the practical knowledge possessed by registered nurses that are part of the Air Force's Critical Care Air Transport Team (CCATT) and distinguish salient features of CCATT knowledge to critical care nursing in the hospital. This research study used descriptive, exploratory methods. Twelve CCATT nurses, identified as experts, were included in the study. Data were collected using written narratives by each participant; group interviews in which nurses discussed the written narratives; and individual interviews. Data were analyzed using interpretive phenomenology. Four major themes developed from the data. The knowledge embedded in CCATT nursing included: preflight preparation, in-flight assessment and environment, characteristics of CCATT nurse, and hospital vs. in-flight nursing practice. CCATT nurses improvise and provide nursing care based on past experiences using a broad critical care knowledge base. This has led to the development of a unique body of knowledge for nursing care. The areas of assessment and preparation described by the CCATT nurses can serve as a template for the Air Force's CCATT training program and CCATT orientation checklists. This study also identified several topics for future research.

Skin interface pressure on the NATO litter.

The NATO litter serves as a transport device and hospital bed during all types of operations. Little is known about the skin interface pressure on this litter. The purpose of this study was to determine whether various types of padding on the litter and body position affect the peak skin interface pressure and the total body area exposed to interface pressures above 30 mm Hg at different body areas. Thirty-two subjects participated. A repeated measures design was used. The surface effect was statistically significant for all peak pressure and surface area analyses (repeated-measures analysis of variance, p < 0.01). There was a significant decrease in peak pressure and surface area between the litter and litter plus aeromedical evacuation mattress. The addition of the blanket did not significantly reduce pressures and should not be considered a pressure-reducing measure. Conversely, an aeromedical evacuation mattress should be used for all high-risk patients if feasible. Preventive measures (turning, elevating the heels) are still required.

Care of the critically ill patient in a military unique environment: a program of research.

The goal of the Air Force Nursing Research Program at WHMC is to conduct research on topics unique to Air Force and military nursing. The nine stressors of flight and the military environment of care have been used as a conceptual model to guide the development of research studies. The studies conducted to date describe how the environment affects practice and when the environment directly affects the patient. The studies conducted are examples of the numerous military nursing research projects supported by funding from the TSNRP. The research funded by TSNRP contributes to the body of nursing knowledge by supporting scientific research, particularly knowledge that is unique to the military. As our nation faces the threat of chemical and biologic attacks, terrorism, and increased deployment of soldiers to battlefields in remote locations throughout the world, it is more important than ever that we ensure the advancement of military nursing research. Supporting research that advances healthcare in peace and in war is critical to the care of our military members and their families. This will require that research funds continue to be available to support military nursing research, that a strong infrastructure to provide resources in support of nursing research programs continues to exist, and that the military nursing corps continues to attract, train, and retain PhD prepared nurse researchers. Given the results of the research completed to date, the following evidence-based practice can be applied to the care of the patient described at the beginning of this article: The nurse positions the patient in the center of the cargo compartment, away from the bulkhead, toward the front of the aircraft, the warmest location during flight. While enroute, the patient will need to be positioned on an aerovac mattress, repositioned frequently, and have his/her heels elevated at all times. Additional padding may be needed for areas adjacent to the litter cross members to reduce pressure on the skin in areas prone to pressure ulcer formation. Should the patient need endotracheal suctioning, the nurse knows that hyperoxygenation-hyperinflation is effective in preventing suctioning-induced hypoxemia. In addition, the suction pressure will need to be increased to account for the effects of altitude without exceeding the pressure limits on the transport ventilator and causing catastrophic ventilator failure. Because there is not enough room on the litter for the chest tube drainage tubing to lay straight, it will be coiled and should dependent loops develop, they should be drained every 15 minutes. This is Air Force nursing research in practice.