Changes In SpO2 Research Articles

The role of capnography in endoscopy patients undergoing nurse-administered propofol sedation: a randomized study

Objective. Standard benzodiazepine/opioid cocktail has proven inferior to propofol sedation during complicated endoscopic procedures and in low-tolerance patients. Propofol is a short-acting hypnotic with a potential risk of respiratory depression at levels of moderate to deep sedation. The existing literature on capnography for endoscopy patients sedated with nurse-administered propofol sedation (NAPS) is limited. Can the addition of capnography to standard monitoring during endoscopy with NAPS reduce the number, duration, and level of hypoxia. Materials and methods.This study was a randomized controlled trial with an intervention group (capnography) and a control group (without capnography). Eligible subjects were consecutive patients for endoscopy at Gentofte Hospital compliant with the criteria of NAPS. Results. Five hundred and forty patients, 263 with capnography and 277 without capnography, were included in the analysis. The number and total duration of hypoxia was reduced by 39.3% and 21.1% in the intervention group compared to the control group (p > 0.05). No differences in actions taken against insufficient respiration were found. Changes in end-tidal carbon dioxide (R = 0.177, p-value < 0.001) and respiratory rate (R = 0.092, p-value < 0.001) were correlated to oxygen saturation (SpO2) up to 36 s prior to changes in SpO2. Conclusions.Capnography seems to reduce the number and duration of hypoxia in NAPS patients (p > 0.05). Capnography is able to detect insufficient respiration that may lead to hypoxia prior to changes in pulse oximetry. However, due to a limited clinical benefit and additional costs associated with capnography, we do not find capnography necessary during the use of NAPS.

Influence of body position on percutaneous nephrolithotomy

Objective To explore the influence of body position on percutaneous nephrolithotomy and its nursing countermeasures.Methods 380 patients undergoing percutaneous nephrolithotomy,including 278 ones(162 taking prone position and 116 taking oblique supine position)whose operation time ≤ 2 hours and 102 ones(70 taking prone position and 32 taking oblique supine position)whose operation time ＞ 2 hours,were retrospective analyzed.Comparisons of the two surgical positions were done in comfort index and the changes of blood pressure(BP),heart rate(HR),and oxygen saturation(SpO2).Results When the operation time ≤ 2 hours,there were no significant differences in BP,HR,SpO2,and comfort index between the patients taking prone position and the patients taking oblique supine position.When the operation time was more than 2 hours,the comfort index was(2.8 ± 1.06)and(1.25 ± 0.6),the change of HR was(17.8 ± 16.0)beats/min and(9.68 ± 10.3)beats/min,and the change of SpO2 was(2.0 ± 1.3)％ and(1.4 ± 0.87)in the patients taking prone position and the patients taking oblique supine position,respectively,with statistical differences(P＜0.01or P＜0.05).Conclusions After taking appropriate nursing countermeasure,the influence of position on vital signs and comfort index can be ignored when the operation time ≤ 2 hours.when prone position is taken and operation time ＞2 hours,cooperation with anesthesiologist should be taken to minimize the influence of body position on vital signs and improve the patients' comfort. Key words: Percutaneous nephrolithotomy; Surgical position; Nursing

Kinetics of Changes in Oxyhemoglobin Saturation During Walking and Cycling Tests in COPD

The patterns and kinetics of changes in SpO2 in the 6-min walk test (6MWT) and cycling test have not been addressed in patients with COPD. We studied 60 COPD subjects, with a mean ± SD FEV1 of 54 ± 18% of predicted. We compared the changes in SpO2 (ΔSpO2) within and between the 2 tests, and the differences between the desaturators and non-desaturators. In the 6MWT there were 4 patterns of SpO2. Desaturation then resaturation was the most common (46%). ΔSpO2 ≥ 3% occurred at approximately 1.2 min, and the nadir was at 3.5 min where resaturation occurred thereafter. The ΔSpO2 between the start and the nadir (start-vs-nadir ΔSpO2) was greater than the start-vs-end ΔSpO2 (P < .001). The desaturators had less inspiratory muscle strength, worse dyspnea, and shorter 6-min walk distance, whereas the resaturators had greater FEV1/FVC and less functional residual capacity (all P < .05). In the cycling test there were 3 patterns of SpO2. Desaturation was the most common (57%). The ΔSpO2 ≥ 3% and nadir SpO2 occurred at 4.6 min and 6.6 min, respectively, of the 6.8-min cycling exercise duration. The desaturators had lower body mass index, lower oxygen-cost diagram score, less post-exercise inspiratory muscle strength, lower diffusing capacity, lower SpO2, lower work during 6MWT, and lower peak exercise performance (all P < .05). In both tests, the start-vs-nadir ΔSpO2 during the 6MWT was greater (P = .02) but the start-vs-end ΔSpO2 was similar (P = .79). The desaturators in both tests had lower oxygen-cost-diagram scores (P < .01) and poorer peak exercise performance. Measurement of start-vs-nadir ΔSpO2 rather than start-vs-end ΔSpO2 during the 6MWT is recommended, because start-vs-nadir ΔSpO2 is greater, and the nadir SpO2 is earlier. In both the 6MWT and the cycling exercise test, desaturation can be predicted with the oxygen-cost-diagram score, which has more capability to predict peak exercise performance than the 6MWT.

A randomized, double-masked, multi-center clinical trial of the injection of the bupivacaine hydrochloride compound for ocular local anaesthesia

Background The injection of the bupivacaine hydrochloride compound ithe preferred method fooculatopical anaesthesiabroad.However,in China,an injection of mixture of lidocaine hydrochloride and bupivacaine hydrochloride iused fothe anesthesia.The mixture injection solution needto be prepared jusprioto surgery.The bupivacaine hydrochloride compound used foinjection habeen approved to producdomestically,buitclinical effectivenesand safety needto be studied.Objective Thiclinical trial wato evaluate the application and safety of the injection of the bupivacaine hydrochloride compound aoculatopical anaesthesia.MethodThe Protocol Review Committee and EthiCommittee approved thitrial.Written informed consenwaobtained from each subjecprioto entering the study.randomized and double-masked multi-centeclinical trial wadesigned by personnel irrelevanto the trial.The unilateral eyeof 223 patientwere included and randomized into the bupivacaine hydrochloride compound group (trial group) and the 2％ lidocaine hydrochloride +0.75％ bupivacaine hydrochloride mixture group (control group).The primary end pointincluded the total score of oculamotility and eyelid activity 2,4,6,8 o10 minuteaftethe injection and athe end of the operation to determine the optimal beginning time of operation.The secondary end poinwathe scoring fopain levelduring the operation.Drug safety waassessed by recording the incidence of oculaand systemiadverse event.The variationin the assessed parameteranalyzed by the intention to treaanalysi(ITT) and per-protocol analysi(PP) between the trial group and the control group were compared by the Wilcoxon rank sum test.ResultOne hundred and eighty-eighpatientwere enrolled in the ITseafteone of them wawithdrawn due to drug response;while 120 patientwere enrolled in the control group.Fothe PP set,109 patientwere included in the trial group afte9 patientwere pulled oudue to non-conformity to the trial parameters,and in the control group,114 patientwere included afte6 patientwere removed due to nonconformity to the trial parameters.There were no significandifferencein the scoreof oculamotility and eyelid activity 2,4,6,8 o10 minuteaftedrug administration and athe end of the operation,awell athe optimal beginning time of operation between the two groups,whetheiwathe ITseand PP se(all aP＞0.05).Oculaand systemiadverse eventwere recorded in 5 patients,with 4 in the trial group and 1 in the control group,withousignificandifference between them (P＞0.05).No statistically significandifferencewere found in the incidenceof pulse abnormality,respiratory change,blood pressure alteration,SPO2 change and electrocardiogram abnormality between the trial group and the control group (all aP＞0.05).ConclusionThe clinical efficacy and safety of the injection of the domestically-made bupivacaine hydrochloride compound aoculalocal anaesthesiare identical to the injection of the mixture of lidocaine hydrochloride and bupivacaine hydrochloride.Iifeasible,economiand easy-to-use during eye surgery. Key words: Drugs and agents; Anesthesia and analgesia; Bupivacaine hydrochloride/compound, injection; Lidocaine hydrochloride/injection; Randomized double-masked multicenter trail; Efficacy; Safety

Regional cerebral blood flow in humans at high altitude: gradual ascent and 2 wk at 5,050 m

The interindividual variation in ventilatory acclimatization to high altitude is likely reflected in variability in the cerebrovascular responses to high altitude, particularly between brain regions displaying disparate hypoxic sensitivity. We assessed regional differences in cerebral blood flow (CBF) measured with Duplex ultrasound of the left internal carotid and vertebral arteries. End-tidal Pco2, oxyhemoglobin saturation (SpO2), blood pressure, and heart rate were measured during a trekking ascent to, and during the first 2 wk at, 5,050 m. Transcranial color-coded Duplex ultrasound (TCCD) was employed to measure flow and diameter of the middle cerebral artery (MCA). Measures were collected at 344 m (TCCD-baseline), 1,338 m (CBF-baseline), 3,440 m, and 4,371 m. Following arrival to 5,050 m, regional CBF was measured every 12 h during the first 3 days, once at 5-9 days, and once at 12-16 days. Total CBF was calculated as twice the sum of internal carotid and vertebral flow and increased steadily with ascent, reaching a maximum of 842 ± 110 ml/min (+53 ± 7.6% vs. 1,338 m; mean ± SE) at ∼ 60 h after arrival at 5,050 m. These changes returned to +15 ± 12% after 12-16 days at 5,050 m and were related to changes in SpO2 (R(2) = 0.36; P < 0.0001). TCCD-measured MCA flow paralleled the temporal changes in total CBF. Dilation of the MCA was sustained on days 2 (+12.6 ± 4.6%) and 8 (+12.9 ± 2.9%) after arrival at 5,050 m. We observed no significant differences in regional CBF at any time point. In conclusion, the variability in CBF during ascent and acclimatization is related to ventilatory acclimatization, as reflected in changes in SpO2.

Application of nanometer calcium phosphate ceramic artificial bone in percutaneous kyphoplasty: a short-term clinical observation

Objective To observe the clinical effects of nanometer calcium phosphate ceramic artificial bone(NCPCAB) in percutaneous kyphoplasty for treatment of osteoporotic vertebral compression fractures. Methods Totally 33 cases of osteoporotic vertebral compression fractures were selected in the present study.All cases were injected with NCPCAB for percutaneous kyphoplasty via bilateral transpedicular balloon approach.Anterior vertebral reset rate and kyphosis correction rate were calculated after treatment.The visual analogue scales(VAS) were observed preoperatively and postoperatively.The changes of blood pressure and SPO2 were observed preoperatively,at injection of the artificial bone,5 min after injection and at the end of surgery. Results The postoperative vertebra reduction rate and kyphosis correction rate were(24.90±3.02)% and(45.80±7.13)%,respectively.The pain was greatly reduced after operation.The blood pressure was stable after injection of the artificial bone,and SPO2 was not markedly different at each time point. Conclusion Application of NCPCAB in percutaneous kyphoplasty is safe and effective for treatment of osteoporotic vertebral compression fractures,with little influence on the vital signs of patients.

Development and evaluation of a video exercise program for locomotive syndrome in the elderly.

OBJECTIVES: To develop and evaluate an exercise program that the elderly could sustainably perform in the community or at home to recover from locomotive syndrome. METHODS: We produced 2 types of teaching media, video and pamphlet, describing 10 physical and mobility training exercises. The pilot study examined changes in pulse rate, percutaneous oxygen saturation (SpO2), and the Borg scale rating of perceived exertion in 20 elderly volunteers. Separately, 120 elderly subjects were recruited and divided into 3 groups according to the teaching medium (video, groupV; pamphlet, groupP; none, groupC). Before and 3months after the intervention, visual analog scale (VAS) scores of low back and knee pain, single-leg standing time, 6-m walking time, Roland-Morris Disability Questionnaire, Oswestry Disability Index, Short Form-8, and 25-question Geriatric Locomotive Function Scale were evaluated. RESULTS: Pulse-rate changes before and after exercise did not exceed 20%, and SpO2 changes were within 4 points in all cases. The Borg scale ranged between 11 and 14. The intergroup comparison revealed the advantage of the video program in improving the VAS of low back pain, left-leg standing time, and 6-m walking time. CONCLUSION: A video exercise program can potentially aid recovery from locomotive syndrome in the elderly.

The Young Everest Study: preliminary report of changes in sleep and cerebral blood flow velocity during slow ascent to altitude in unacclimatised children

BackgroundCerebral blood flow velocity (CBFV) and sleep physiology in healthy children exposed to hypoxia and hypocarbia are under-researched.AimTo investigate associations between sleep variables, daytime end-tidal carbon dioxide (EtCO2) and CBFV...

Is resistance exercise with controlled frequency breathing superior to training of the same program with normal breathing? – future challenges

The specific internal environment in the body during exercise can influence the muscle hypertrophy and strength response. Unlike chronic hypoxic exposure, exercise training under intermittent hypoxia may lead to muscle hypertrophy with relatively low workloads. Objectives: The purpose of this brief review is to discuss how a hypoxic condition can be attained without providing ambient inspiratory hypoxic gases or inducing hypobaric hypoxia. Design and Methods: Evidence-based implications and future challenges. Results: Pulse oximetry is a simple method that measures percutaneous oxygen saturation (SpO2). Several studies reported that hypoxia is produced with increasing duration of apnea, especially in the last half of the breath-hold, with SpO2 reaching levels as low as 80%. Similarly, studies have reported changes in SpO2 during dynamic exercise at various workloads with controlled frequency breathing. Conclusions and future challenges: These results suggest a possibility that moderate- or high-intensity exercise combined with controlled frequency breathing may produce a low level of SpO2, which may be a model for muscle hypertrophy by moderate- or high-intensity exercise training with hypoxia. However, there are no published studies on the effects of resistance exercise with controlled frequency breathing on muscle size and function. Additionally, it is unclear the magnitude change in SpO2 during resistance exercise with a combination of different frequencies of breathing and various workloads. Furthermore, the safety of such a technique, particularly with respect to hypercapnia and the possible elevation of arterial pressures, is also unknown and should be investigated further.

Correlation of pulse oximetry and apgar scoring in the normal newborns.

Context:Apgar score (AS) is routinely used for assessment of newborns immediately after birth. Within acceptable limits, low saturations at birth are normal in vigorous newborn babies. Various studies have questioned the reliability of AS.Aims:To detect whether AS is an accurate indicator of hypoxemia and to study the correlation of different components of AS with the arterial oxygenation saturation (SpO2) levels of normal newborns in the delivery room.Settings and Design:A prospective cross-sectional observational study on normal healthy neonates delivered vaginally in a tertiary level referral medical college.Materials and Methods:SpO2 levels were monitored continuously in the newborns with a pulse oximeter and serial recording of SpO2 levels was done at 5 min intervals starting at 1 min of life until 30 min after birth. Simultaneously, AS was recorded in these newborns at 1 and 5 min of life.Statistical Analysis:Data was analyzed using the Mann-Whitney–U test.Results:AS at 1 and 5 min of life didn’t correlate with the changes in SpO2 of newborns. In AS; though respiratory efforts and muscle tone were significantly correlated with SpO2 of the newborns, body color did not have significant correlation with simultaneously recorded SpO2.Conclusions:A revised AS in which evaluation of color is replaced by pulse oximetry monitoring would prove to be a better tool for neonatal evaluation in the immediate postnatal period.

Evaluation of hemodynamic and SpO2 variability during different stages of periodontal surgery

Background:Changes in pulse rate and blood pressure are common consequences during oral surgeries. Hypoxia during surgical process is another side effect. The objective of the present study was evaluation of blood hemoglobin oxygenation and hemodynamic changes during periodontal surgery.Materials and Methods:This clinical trial study was conducted upon 50 subjects aged 30-55 years who referred to the clinic of dental faculty of Babol University and needed periodontal surgery with modified widman flaps in the anterior section of the maxilla. Pulse rate, blood pressure, and pulse oximetric evaluations were recorded in five stages during surgery.Results:The average of systolic and diastolic blood pressure had been in their maximum amount in the second stage of evaluation and minimum amounts were in the first one; while pulse rate changes were greatest in the second stage and lowest in the fifth stage. Analyzing the data revealed no significant difference in Blood Oxygen Saturation (SpO2) measurements in none of the stages evaluated.Conclusions:Blood pressure and heart rate increased significantly after the injection of anesthetic drug and in further phases they were decreased after the elimination of stimulating effect of adrenaline. SpO2 changes were not significantly prominent.

Bradycardia during laparoscopic surgery due to high flow rate of CO2insufflation

Bradycardia during laparoscopic surgery due to high flow rate of CO₂insufflation

Role of Sucrose in Reducing Painful Response to Orogastric Tube Insertion in Preterm Neonates

To study whether orogastric tube (OGT) insertion elicits a painful response in preterm neonates, and the role of oral sucrose in reducing this pain. This double blinded, randomized control trial was conducted in the neonatal intensive care units of Kalawati Saran Children's Hospital. Clinically stable preterms within the first 7 postnatal days, who had not received painful stimulus 30 min prior to intervention, and who required routine OGT insertion were included. Lingual 24 % sucrose or distilled water (1 ml) was administered 2 min before OGT insertion. The primary outcome was painful response assessed by Premature Infant Pain Profile scale (PIPP), while the secondary outcomes were heart rate and SpO2 changes. The trial is registered with ClinicalTrials.gov ( NCT 00949104) RESULTS: Sixty preterms were randomized in each group. Final analysis was carried out on 52 subjects in the placebo group and 53 in the sucrose group. The mean intra-procedure PIPP scores were significantly higher than the mean pre-procedure PIPP scores, in the gestational age groups of more than 34 wk, and 32 wk to 33 wk, 6 d, in both the placebo (7.25 vs. 3, and 8.14 vs. 3.14, respectively) and sucrose arm (8.06 vs. 3.21, and 7.18 vs. 4.18, respectively). The mean PIPP scores assessed at 30 s post procedure in the sucrose group were significantly lower than the placebo group (4.32 vs. 5.6, p = 0.014). No significant adverse events were seen. OGT insertion causes pain in preterms and single dose lingual 24 % sucrose may alleviate this pain.

Transient decrease in PaCO2 and asymmetric chest wall dynamics in early progressing pneumothorax

Diagnosis of pneumothorax (PTX) in newborn infants has been reported as late. To explore diagnostic indices for early detection of progressing PTX, and offer explanations for delayed diagnoses. Progressing PTX was created in rabbits (2.3 ± 0.5 kg, n = 7) by injecting 1 ml/min of air into the pleural space. Hemodynamic parameters, tidal volume, EtCO(2), SpO(2), blood gas analyses and chest wall tidal displacements (TDi) on both sides of the chest were recorded. (Mean ± SD): A decrease in SpO(2) below 90 % was detected only after 46.6 ± 11.3 min in six experiments. In contrary to the expected gradual increase of CO(2), there was a prolonged transient decrease of 14.2 ± 4.5 % in EtCO(2) (p < 0.01), and a similar decrease in PaCO(2) (p < 0.025). EtCO(2) returned back to baseline only after 55.2 ± 24.7 min, and continued to rise thereafter. The decrease in CO(2) was a mirror image of the 14.6 ± 5.3 % increase in tidal volume. The analysis of endotracheal flow and pressure dynamics revealed a paradoxical transient increase in the apparent compliance. Significant decrease in mean arterial blood pressure was observed after 46.2 ± 40.1 min. TDi provided the most sensitive and earliest sign of PTX, decreasing on the PTX side after 16.1 ± 7.2 min. The TDi progressively decreased faster and lower on the PTX side, thus enabling detection of asymmetric ventilation. The counterintuitive transient prolonged decrease in CO(2) without changes in SpO(2) may explain the delay in diagnosis of PTX encountered in the clinical environment. An earlier indication of asymmetrically decreased ventilation on the affected side was achieved by monitoring the TDi.

Forehead-Mounted Reflectance Oximetry for In-Cockpit Hypoxia Early Detection and Warning

Effective hypoxia-related mishap prevention relies upon aircrew rapid recognition of hypoxia symptoms. The objectives of this experiment were twofold: to compare the effectiveness of a forehead-mounted reflectance oximeter and finger-mounted pulse oximeter for application in a hypoxia early warning detection system, and to determine whether the forehead-mounted sensor could be placed within an aviation helmet. Subjects donned an aviation flight mask and were instrumented with a forehead reflectance oximeter, a finger pulse oximeter, a blood pressure cuff, and a skin temperature sensor. Following instrumentation, subjects breathed ambient air for 10 min through the Reduced Oxygen Breathing Device (ROBD) to allow for acclimation. The baseline period was followed by one of two counterbalanced ascent profiles used to model rapid exposures to altitude. Data were collected at 1 Hz from both sensors for the duration of the protocol. Analyses indicated an exceptionally strong agreement between the forehead and finger sensors at all ranges of desaturation. The sensitivity data revealed that the forehead sensor was significantly faster when responding to rapid changes in SpO2 than the finger. The sensor was successfully integrated inside the helmet; however, once donned by the subject, there was considerable artifact due to pressure fluctuations. While these data may seem to suggest that the forehead sensor is accurate and sensitive to altitude induced changes in SpO2, major drawbacks exist for the technology utilized in the current study. Significant improvements aimed at diminishing noise, curbing motion artifact, and improving reliability are required to reduce errant measurements.

Domestic imipenem cilastatin sodium for the treatment of severe aspiration pneumonia, a curative effect observation

To evaluate the efficacy and safety of domestic imipenem cilastatin sodium for the treatments of severe aspiration pneumonia. A randomize, open, parallel-controlled trial was conducted. Sixty-eight patients with severe aspiration pneumonia were divided into trial group (n=36) and control group (n=32) by random distribution method. The application of trial group domestic imipenem cilastatin sodium was 1.0 g intravenous drip, every 6-8 hours for 7-14 days. The control group application with imported injection imipenem cilastatin sodium was 1.0 g intravenous drip, every 6-8 hours for 7-14 days. The highest daily temperature (T), heart rate (HR), breathing rate (RR), pulse blood oxygen saturation (SpO(2)), blood oxygen partial pressure (PaO(2)), inhaled oxygen concentration (FiO(2)), oxygenation index (PaO(2)/FiO(2)), airway peak pressure (Paw), minute ventilation (MV) and white blood count (WBC), pro calcitonin (PCT), high-sensitivity C-reactive protein (hs-CRP) index before and 1, 3, 7 days after treatment, and liver and kidney function, chest X-rays, and sputum cultures of drug sensitive test were conducted. And the effectiveness and safety were determined according to the standards. After treatment indexes of the two groups were obviously improved, i. e. T, HR, RR, Paw, MV, the WBC, PCT, CRP were gradually declined, PaO(2)/FiO(2) was gradually raised. There were statistical significance before and 3 days after treatment in the trial and the control group [T: 37.35±0.91 centigrade vs. 38.43±1.06 centigrade, 37.28±0.88 centigrade vs. 38.35±1.11 centigrade; HR: 90.25±10.60 bpm vs. 118.94±15.46 bpm, 89.31±11.17 bpm vs. 124.34±17.87 bpm; RR: 25.14±3.17 bpm vs. 32.28±4.49 bpm, 24.81±2.43 bpm vs. 33.13±4.17 bpm; Paw: 23.03±3.04 cm H(2)O vs. 33.22±4.59 cm H(2)O, 22.75±3.22 cm H(2)O vs. 33.63±4.79 cm H(2)O; MV: 8.67±1.26 L/min vs. 11.80±2.01 L/min, 8.88±1.45 L/min vs. 13.21±2.90 L/min; WBC: 11.26±1.96 ×10(9)/L vs. 14.57±3.10 ×10(9)/L, 12.28±3.38 ×10(9)/L vs. 15.25±4.93 ×10(9)/L; PCT: 6.90±5.46 μg/L vs. 16.97±7.93 μg/L, 6.17±6.13 μg/L vs. 21.26±11.54 μg/L; CRP: 85.50±37.91 mg/L vs. 120.17±45.47 mg/L, 94.31±38.51 mg/L vs. 142.34±53.57 mg/L; PaO(2)/ FiO(2): 182.06±40.88 mm Hg vs. 98.67±20.62 mm Hg, 184.09±43.78 mm Hg vs. 96.22±22.59 mm Hg, all P<0.05]. There was no significant change in SpO(2) before and after treatment in two groups. And the total clinical effective rate in trial and control group were 83.4% and 81.2%, adverse reaction rate were 13.9% and 9.4%, bacterial removal rate were 90.3% and 87.0% respectively, and there was no significant difference between the two groups (all P>0.05). Domestic imipenem cilastatin sodium can effectively control severe aspiration pneumonia, and it is safe and effective antibiotics.

Effects of Commercial Air Travel on Patients With Pulmonary Hypertension

<h3>Background</h3> Limited data are available on the effects of air travel in patients with pulmonary hypertension (PH), despite their risk of physiologic compromise. We sought to quantify the incidence and severity of hypoxemia experienced by people with PH during commercial air travel. <h3>Methods</h3> We recruited 34 participants for a prospective observational study during which cabin pressure, oxygen saturation (Spo₂), heart rate, and symptoms were documented serially at multiple predefined time points throughout commercial flights. Oxygen desaturation was defined as Spo₂ < 85%. <h3>Results</h3> Median flight duration was 3.6 h (range, 1.0-7.3 h). Mean ± SD cabin pressure at cruising altitude was equivalent to the pressure 1,968 ± 371 m (6,456 ± 1,218 ft) above sea level (ASL) (maximum altitude=2,621 m [8,600 ft] ASL). Median change in Spo₂ from sea level to cruising altitude was −4.9% (range, 2.0% to −15.8%). Nine subjects (26% [95% CI, 12%-38%]) experienced oxygen desaturation during flight (minimum Spo₂ = 74%). Thirteen subjects (38%) reported symptoms during flight, of whom five also experienced desaturations. Oxygen desaturation was associated with cabin pressures equivalent to > 1,829 m (6,000 ft) ASL, ambulation, and flight duration (all <i>P</i> values < .05). <h3>Conclusions</h3> Hypoxemia is common among people with PH traveling by air, occurring in one in four people studied. Hypoxemia was associated with lower cabin pressures, ambulation during flight, and longer flight duration. Patients with PH who will be traveling on flights of longer duration or who have a history of oxygen use, including nocturnal use only, should be evaluated for supplemental in-flight oxygen.

Inhaled Fentanyl Aerosol in Healthy Volunteers

Rapid delivery of potent opioid to the systemic circulation is an important feature for the effective treatment of acute and acute-on-chronic breakthrough pain. The delivery of different opioids by the pulmonary route has been inconsistent, usually resulting in low bioavailability of the drug. Staccato® Fentanyl for Inhalation is a handheld inhaler producing a single metered dose of aerosolized fentanyl during a single inspiration. The aerosol is of high purity (≥98%) at a particle size (1 to 3.5 microns) shown to be best for pulmonary absorption. We conducted the study in healthy volunteers in 2 stages. In the crossover stage, 10 subjects received IV fentanyl 25 µg and inhaled fentanyl 25 µg on separate occasions. The dose escalation stage was a multidose, randomized, double-blind, placebo-controlled, single-period dose escalation study of inhaled fentanyl (50 to 300 µg). Serial blood sampling was performed over an 8-hour period after drug administration to determine the pharmacokinetic profile, and serial pupillometry was performed as a measure of pharmacodynamic effect. In the crossover stage the pharmacokinetic profiles of the inhaled and IV fentanyl showed similar peak arterial concentrations and areas under the curve. The time to maximum concentration was slightly shorter for the inhaled than IV fentanyl, 20.5 and 31.5 seconds, respectively. In the dose escalation stage the administration of repeated doses resulted in predictable, dose-dependent serum concentrations. This study has demonstrated that the pharmacokinetic profile of single doses of inhaled fentanyl is comparable to IV administration.

Evaluation of cerebral ischemia using near-infrared spectroscopy with oxygen inhalation

Conventional methods presently used to evaluate cerebral hemodynamics are invasive, require physical restraint, and employ equipment that is not easily transportable. Therefore, it is difficult to take repeated measurements at the patient's bedside. An alternative method to evaluate cerebral hemodynamics was developed using near-infrared spectroscopy (NIRS) with oxygen inhalation. The bilateral fronto-temporal areas of 30 normal volunteers and 33 patients with cerebral ischemia were evaluated with the NIRS system. The subjects inhaled oxygen through a mask for 2 min at a flow rate of 8 L/min. Principal component analysis (PCA) was applied to the data, and a topogram was drawn using the calculated weights. NIRS findings were compared with those of single-photon-emission computed tomography (SPECT). In normal volunteers, no laterality of the PCA weights was observed in 25 of 30 cases (83%). In patients with cerebral ischemia, PCA weights in ischemic regions were lower than in normal regions. In 28 of 33 patients (85%) with cerebral ischemia, NIRS findings agreed with those of SPECT. The results suggest that transmission of the changes in systemic SpO2 were attenuated in ischemic regions. The method discussed here should be clinically useful because it can be used to measure cerebral ischemia easily, repeatedly, and noninvasively.

Correlation between cognitive ability measured by response time of 1‐back task and changes of SpO2 by supplying three different levels of oxygen in the elderly

This study investigated the correlation between response time of the 1-back task and changes of blood oxygen saturation (SpO2 ) by supplying three different levels of oxygen (21%, 1 L/min; 93%, 1 L/min; 93%, 5 L/min) in the elderly. A total of 17 older adults (mean age 72.9 ± 4.7 years) participated in the experiment. A 1-back task was used as a cognitive task. The experiment consisted of three phases, which included the adaptation phase (3 min) after oxygen administration, the control phase (2 min) that maintained a stable condition before the task, and the task phase (2 min) where the 1-back task was carried out. SpO2 was measured during each phase. As concentration level and supply of oxygen increased, SpO2 increased and response time of the 1-back task decreased. Highly concentrated oxygen administration can increase SpO2 in the elderly and an increase in cognitive performance, such as a decrease in response time, can be observed.