Cognitive and psychomotor responses to high-altitude exposure in sea level and high-altitude residents of Ecuador.

BACKGROUND: High-altitude inhabitants have cardiovascular and respiratory adaptations that are advantageous for high-altitude living, but they may have impaired cognitive function. This study evaluated the influence of altitude of residence on cognitive and psychomotor function upon acute exposure to very high altitude. FINDINGS: Ecuadorians (31 residing at 0-1,500 m [LOW], 78 from 1,501-3,000 m [MOD], and 23 living >3,000 m [HIGH]) were tested upon their arrival to a hut at 4,860 m on Mount Chimborazo. Cognitive/psychomotor measurements included a go-no-go test (responding to a non-visual stimulus), a verbal fluency test (verbalizing a series of words specific to a particular category), and a hand movement test (rapidly repeating a series of hand positions). Mean differences between the three altitude groups on these cognitive/psychomotor tests were evaluated with one-way ANOVA. There were no significant differences (p = 0.168) between LOW, MOD, and HIGH for the verbal fluency test. However, the go-no-go test was significantly lower (p < 0.001) in the HIGH group (8.8 ± 1.40 correct responses) than the LOW (9.8 ± 0.61) or MOD (9.8 ± 0.55) groups, and both MOD (97.9 ± 31.2) and HIGH (83.5 ± 26.7) groups completed fewer correct hand movements than the LOW (136.6 ± 37.9) subjects (p < 0.001). CONCLUSIONS: Based on this field study, high-altitude residents appear to have some impaired cognitive function suggesting the possibility of maladaptation to long-term exposure to hypobaric hypoxia.

Results of a clinical practice algorithm for the management of thoracostomy tubes placed for traumatic mechanism.

INTRODUCTION: The management and removal of thoracostomy tubes for trauma-related hemothorax and pneumothorax is controversial. General recommendations exist; however, institutional data related to an algorithmic approach has not been well described. The difficulty in establishing an algorithm centers about individualized patients' needs for subsequent management after thoracostomy tube placement. In our institution, we use the same protocol for all trauma patients who receive a thoracostomy tube with minimal complications. PURPOSE: To present the clinical outcomes of patients who required a tube thoracostomy for traumatic injury and were managed by an institutional protocol. METHODS: A retrospective chart review of 313 trauma patients at a single level I trauma institution from January 2008 through June 2012 was conducted. Inclusion criteria were patient age ≥ 18 years, involvement in a trauma, and requirement of a thoracostomy tube. The patients' charts were reviewed for demographic data, injury severity score (ISS), length of stay (LOS), and chest-tube specific data. Thoracostomy tube complications were defined as persistent air leak, persistent pneumothorax, recurrent pneumothorax, and clotting of thoracostomy tube. The patients were managed per our institutional algorithm. Descriptive statistics were performed. RESULTS: Most of the patients who required a thoracostomy tube had blunt-related traumas (271/313; 86.6%), while 42 patients (13.4%) sustained penetrating injuries. There were 215 (68.7%) male patients. The average age at time of injury was 45.7 ± 21.1 years and the mean ISS was 24.9 ± 15.9 (mean ± SD). Elevated alcohol levels were found in 65 of the 247 patients who were tested upon admission (26.3%). Overall, 15 patients (4.8%) developed a thoracostomy tube related complication: persistent air leak in six patients, persistent pneumothorax in six patients, recurrent pneumothorax in two patients, and clotted thoracostomy tube in one patient. The average LOS was 10.4 ± 8.4 days, and the mean length of thoracostomy tube placement was 5.9 ± 4.3 days. CONCLUSIONS: Our algorithmic thoracostomy tube management protocol resulted in a complication rate of 4.8%. By managing thoracostomy tubes in a systematic manner, our patients have improved outcomes following placement and removal compared to other studies.

Orthostatic responses at 4860 m in low, moderate, and high altitude residents.

This study evaluated the influence of altitude of residence on orthostatic responses when exposed to high altitude. Data collection took place at the Carrel hut (4860 m) on Chimborazo in Ecuador. After being transported to the hut by vehicle, 69 people volunteered for the study. A 3-min stand test (rapid change from supine to standing) provided an orthostatic challenge while resting heart rate (RHR), systolic (SBP) and diastolic (DBP) blood pressures, and arterial oxygen saturation (SpO2) were measured. Participants were separated into four groups based on altitude of residence and ethnicity: LOW (<1500 m; n=15), MOD (1500-3000 m, n=30), and HIGH (>3000 m, n=11) Ecuadorians, and non-Ecuadorian lowlanders (NE-LOW, n=13). Supine and standing RHRs were lower (p<0.05) for HIGH compared to other groups. Furthermore, standing increased RHR in LOW, MOD, and NE-LOW by 11.9 ± 5.3, 9.5 ± 4.1, and 11.6 ± 7.4 bpm, respectively, while HIGH stayed the same (0.6 bpm increase ± 3.3). Additionally, mean arterial pressure decreased slightly but not significantly upon standing in all groups except HIGH. The difference in Spo2 among groups was not significant (p>0.05). Altitude of residence influences the cardiovascular responses to orthostatic stress with HIGH having blunted responses and greater tolerance.