Adaptation to altitude as a vehicle for experiential learning of physiology by university undergraduates

2007 ◽  
Vol 31 (3) ◽  
pp. 270-278 ◽  
Author(s):  
David S. Weigle ◽  
Amelia Buben ◽  
Caitlin C. Burke ◽  
Nels D. Carroll ◽  
Brett M. Cook ◽  
...  

In this article, an experiential learning activity is described in which 19 university undergraduates made experimental observations on each other to explore physiological adaptations to high altitude. Following 2 wk of didactic sessions and baseline data collection at sea level, the group ascended to a research station at 12,500-ft elevation. Here, teams of three to four students measured the maximal rate of oxygen uptake, cognitive function, hand and foot volume changes, reticulocyte count and hematocrit, urinary pH and 24-h urine volume, athletic performance, and nocturnal blood oxygen saturation. Their data allowed the students to quantify the effect of altitude on the oxygen cascade and to demonstrate the following altitude-related changes: 1) impaired performance on selected cognitive function tests, 2) mild peripheral edema, 3) rapid reticulocytosis, 4) urinary alkalinization and diuresis, 5) impaired aerobic but not anaerobic exercise performance, 6) inverse relationship between blood oxygen saturation and resting heart rate, and 7) regular periodic nocturnal oxygen desaturation events accompanied by heart rate accelerations. The students learned and applied basic statistical techniques to analyze their data, and each team summarized its results in the format of a scientific paper. The students were uniformly enthusiastic about the use of self-directed experimentation to explore the physiology of altitude adaptation and felt that they learned more from this course format than a control group of students felt that they learned from a physiology course taught by the same instructor in the standard classroom/laboratory format.

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Jie Chang ◽  
Chun Yang

Sufficient propofol or fentanyl doses necessary to prevent the response to skin incision do not necessarily reduce hemodynamic responses during surgery. The purpose of this study was to characterize the pharmacodynamic interaction between propofol and fentanyl with respect to the sedative effects and safety during painless gastrointestinal endoscopy. From October 2018 to October 2020, 200 patients undergoing painless gastrointestinal endoscopy in our department’s outpatient or inpatient clinic were selected and randomly divided into a control group and an observation group, 100 patients per group. Prior to surgery, the patients in the two groups were required to be connected to an electrocardiogram monitor and then were instructed to lie on the left side and receive continuous oxygen infusion of 2-3 L/min with a nasal cannula. The control group was injected with propofol injection (100 mg/min). The observation group was given fentanyl intravenous injection at a dose of 0.1 μg/kg followed by propofol injection (100 mg/min). Painless gastrointestinal endoscopy was performed after the patients entered a sleep state and the eyelash reaction disappeared. Outcome analysis was performed on preoperative and intraoperative hemodynamic indicators, including heart rate, blood oxygen saturation, dose of propofol, time for endoscopy, recovery time, hospitalization after recovery, Montreal Cognitive Assessment (MoCA) score, and Mini-Mental State Examination (MMSE) score. The incidence rate of adverse reactions in the observation group was 6%, which was notably lower than that of the control group (18%). The total response rate of the observation group was 98%, which was significantly higher than that of the control group (90%) ( P < 0.05 ). The intraoperative heart rate and blood oxygen saturation of the observation group were higher than those of the control group ( P < 0.0 ss ). The patients receiving sedation with propofol plus fentanyl had fewer doses of propofol and shorter recovery time than those receiving propofol alone ( P < 0.05 ). It was also revealed that the patients receiving sedation with propofol plus fentanyl exhibited more MoCA and MMSE scores than those receiving propofol alone 30 min after sedation during painless gastrointestinal endoscopy. Taken together, sedation with propofol combined with fentanyl was more effective and safer than that with propofol alone in painless gastrointestinal endoscopy, which can ensure a wake-up state, stable breathing cycle, and better gastrointestinal painless procedure.


2018 ◽  
Vol 12 (3) ◽  
pp. 82-85
Author(s):  
Xiaoling Chen ◽  
Yuelan Qin ◽  
Fanghua Gong

BackgroundUndergoing general anesthesia and pneumoperitoneum could affect the lung function and comprise oxygenation in laparoscopic cholecystectomy patients. Position of patients after surgery may affect lung function of these patients.AimTo observe the effect of semi-recumbent position on blood oxygen saturation (SpO2) in postanesthetic patients after laparoscopic cholecystectomy.MethodsA number of 225 patients who admitted to postanesthetic care unit after laparoscopic cholecystectomy from September 2016 to May 2017 were randomly assigned into the intervention group and the control group. The intervention group adopted a semi-recumbent position with head bed elevation by 10 to 20°, while the control received a supine position without lying on a pillow. Both groups received routine postanesthesia care. Data on SpO2 before and after extubation were collected. Independent t-test was used for data analysis.ResultsThere was no vomiting and cough reactions before and after extubation in both groups. Intervention group reported a significantly higher level of SpO2 at 1 minute and 30 minutes after extubation, compared to the control group (both ps < 0.05).ConclusionSemi-recumbent position with the head bed elevation could significantly increase the SpO2 level of postanesthetic patients, thus ensuring the safety of patients when removing the endotracheal tube.


2021 ◽  
Vol 27 (5) ◽  
pp. 509-513
Author(s):  
Rui Li

ABSTRACT Introduction: Due to various uncertain and unexpected factors in life such as diseases, natural disasters, traffic accidents, and congenital disabilities, the number and proportion of lower limb amputations are still rising for many reasons, so the research on lower limb prostheses is particularly important. Objective: This work aimed to study the relationship between altitude exercise and cardiopulmonary function. Methods: A model of abnormal changes in cardiopulmonary function was established, and then 40 plateau exercisers were selected, all of whom arrived in Tibet in March 2017. The relationship between pulmonary circulation volume and internal pressure in the chest was observed and compared. The relationship between cardiopulmonary sensory reflex and exercise (high altitude) breathing and heart rate was analyzed. A comparison of the cardiopulmonary function of subjects of different genders was implemented. Moreover, the influence of different altitudes on the subjects’ cardiopulmonary function and the subjects’ cardiopulmonary function changes before departure and during the first, second, and third week after departure were observed and compared. Results: I. As the pressure in the thoracic cavity increased, the subjects’ pulmonary circulation blood volume gradually decreased, and the decrease was most obvious in the stage of thoracic pressure −50 to 0. II. As the cardiorespiratory reflex coefficient increased, the subjects’ breathing and heart rate compensatory acceleration appeared. III. Tracking and monitoring of the subjects’ cardiopulmonary indicators revealed that with the increase in altitude, the subjects’ average arterial pressure, respiratory frequency, and heart rate all showed an upward trend, while the blood oxygen saturation value showed a downward trend. IV. No matter how high the altitude was, the average arterial pressure, respiratory rate, and heart rate monitored of the subjects under exercise were significantly superior to the indicator values under resting state. In contrast, the blood oxygen saturation value showed the opposite trend. V. The subjects’ average arterial pressure, respiration, and heart rate in the first week were higher than other periods, but the blood oxygen saturation was relatively lower. In the second and third weeks, the changes in cardiopulmonary function were relatively smooth (all P<0.05). VI. The changes in the index of the cardiopulmonary function of subjects of different genders were small (p>0.05). Conclusion: Through modeling, the results of the plateau environment on the cardiopulmonary function of the body were made clearer, and these research data provided theoretical references for the training of the sports field in the plateau area. Level of evidence II; Therapeutic studies - investigation of treatment results.


Sensors ◽  
2020 ◽  
Vol 20 (23) ◽  
pp. 6849
Author(s):  
Marta Vicente-Rodríguez ◽  
Damián Iglesias Gallego ◽  
Juan Pedro Fuentes-García ◽  
Vicente Javier Clemente-Suárez

This study aims to analyze the psychophysiological stress response of a helicopter crew using portable biosensors, and to analyze the psychophysiological stress response differences of experienced and non-experienced crew members. We analyzed 27 participants (33.89 ± 5.93 years) divided into two different flight maneuvers: a crane rescue maneuver: 15 participants (three control and 12 military) and a low-altitude maneuver: 12 participants (five control and seven military). Anxiety, rating of perceived exertion, subjective perception of stress, heart rate, blood oxygen saturation, skin temperature, blood lactate, cortical arousal, autonomic modulation, leg and hand strength, leg flexibility, spirometry, urine, and short-term memory were analyzed before and after both helicopter flight maneuvers. The maneuvers produced a significant increase in stress and effort perception, state of anxiety, and sympathetic modulation, as well as a significant decrease in heart rate, blood oxygen saturation, leg and inspiratory muscle strength, and urine proteins. The use of biosensors showed how a crane rescue and low-altitude helicopter maneuvers produced an anticipatory anxiety response, showing an increased sympathetic autonomic modulation prior to the maneuvers, which was maintained during the maneuvers in both experienced and non-experienced participants. The crane rescue maneuver produced a higher maximal heart rate and decreased pulmonary capacity and strength than the low-altitude maneuver. The psychophysiological stress response was higher in the experienced than in non-experienced participants, but both presented an anticipatory stress response before the maneuver.


2006 ◽  
Vol 31 (4) ◽  
pp. 281-293 ◽  
Author(s):  
Soon-Cheol Chung ◽  
Sunao Iwaki ◽  
Gye-Rae Tack ◽  
Jeong-Han Yi ◽  
Ji-Hye You ◽  
...  

2021 ◽  
Author(s):  
Jing Zhang ◽  
Danyang Gao ◽  
Pengfei Liu ◽  
Tianzuo Li

Abstract Objective: To investigate the residual effects of cis-atracurium with different administrations in patients with hyperthermic intraperitoneal chemotherapy.Methods: 60 patients undergoing hyperthermic intraperitoneal chemotherapy were randomly divided into two groups with 30 cases in each group. All patients were induced with sufentanil 0.4ug/kg, propofol 2.0mg/kg and cis atracurium 0.2mg/kg. During the operation, sevoflurane and remifentanil were used to maintain anesthesia. BIS value was 45-55. The control group intermittently received cis-atracurium injection with 0.1mg/kg/h. The experimental group received continuous injection of cis-atracurium at a rate of 1.5ug/kg/min. Cis-atracurium was discontinued 30min before the end of the operation, sevoflurane inhalation was stopped 20min before the end of the surgery and remifentanil was discontinued 10min before the end. At the end of the operation, no muscle relaxant antagonism were applied. General information of patients was recorded. Mean arterial pressure (MAP), heart rate (HR), tidal volume (VT), respiratory rate (F), and blood oxygen saturation (SpO2) were recorded before anesthesia (T1) , at the time of tracheal catheter extraction (T2).Besides, the total amount of cis-atracurium, the time of recovery of spontaneous tidal volume to 6ml/kg (t1), the time of continuous lifting of the head for 5 s (t2), and the time from the withdrawal of muscle relaxant to the removal of the tracheal catheter (t3) were recorded. Blood gas analysis was also performed to record PaO2 and PaCO2 before anesthesia, when leaving the operating room and SICU. Moreover, relevant adverse reactions were recorded.Results: 1) general situation: there was no difference in body weight, operation time, ASA classification and other indicators between the two groups (P>0.05). 2) comparison of residual effects of muscle relaxants: the values of t1, t2 and t3 in the experimental group were significantly shorter than those in the control group (P<0.05). There was no significant difference between the two groups in PaO2 and PaCO2 before anaesthesia, when out of the operating room and when out of SICU (P>0.05). 3) hemodynamic comparison: there were no statistically significant differences in mean arterial pressure, heart rate, tidal volume, respiratory rate and blood oxygen saturation between the two groups at time points T1 and T2 (P>0.05). 4) comparison of adverse events: no adverse events occurred in either group.Conclusion: Compared with intermittent infusion, continuous infusion of cis-atracurium did not result in significant residual muscle relaxation and no significant histamine release. Therefore, continuous infusion is more suitable for long-term surgery.


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