scholarly journals Physiological effects and subjective tolerability of prone positioning in COVID-19 and healthy hypoxic challenge

2021 ◽  
pp. 00524-2021
Author(s):  
Akhilesh Jha ◽  
Fangyue Chen ◽  
Sam Mann ◽  
Ravi Shah ◽  
Randa Abu-Youssef ◽  
...  
Keyword(s):  
Heart Rate ◽  
Respiratory Rate ◽  
Supine Position ◽  
Subjective Symptom ◽  
Prone Positioning ◽  
Hospitalised Patients ◽  
Single Centre Study ◽  
Healthy Control ◽  
End Tidal ◽  
Ventilated Patients

BackgroundProne positioning has a beneficial role in COVID-19 patients receiving ventilation but lacks evidence in awake non-ventilated patients, with most studies being retrospective, lacking control populations and information on subjective tolerability.MethodsWe conducted a prospective, single-centre study of prone positioning in awake non-ventilated patients with COVID-19 and non-COVID-19 pneumonia. The primary outcome was change in peripheral oxygenation in prone versus supine position. Secondary outcomes assessed effects on end-tidal CO2, respiratory rate, heart rate, and subjective symptoms. We also recruited healthy volunteers to undergo proning during hypoxic challenge.Results238 hospitalised patients with pneumonia were screened; 55 were eligible with 25 COVID-19 patients and 3 non-COVID-19 patients agreeing to undergo proning – the latter insufficient for further analysis. 10 healthy control volunteers underwent hypoxic challenge. Patients with COVID-19 had a median age of 64 years (interquartile range [IQR] 53–75). Proning led to an increase in SpO2 compared to supine position (difference +1.62%; p=0.003) and occurred within 10 min of proning. There were no effects on end-tidal CO2, respiratory rate, or heart rate. There was an increase in subjective discomfort (p=0.003), with no difference in breathlessness. Among healthy controls undergoing hypoxic challenge, proning did not lead to a change in SpO2 or subjective symptom scores.ConclusionIdentification of suitable patients with COVID-19 requiring oxygen supplementation from general ward environments for awake proning is challenging. Prone positioning leads to a small increase in SpO2 within 10 min of proning though is associated with increased discomfort.

Developmental pattern of hypercapnic and hypoxic ventilatory responses from childhood to adulthood

1994 ◽  
Vol 76 (1) ◽  
pp. 314-320 ◽  
Author(s):  
C. L. Marcus ◽  
W. B. Glomb ◽  
D. J. Basinski ◽  
S. L. Davidson ◽  
T. G. Keens
Keyword(s):  
Heart Rate ◽  
Body Weight ◽  
Body Size ◽  
Respiratory Rate ◽  
Body Surface ◽  
Vital Capacity ◽  
Developmental Pattern ◽  
Ventilatory Responses ◽  
End Tidal ◽  
Arterial O2 Saturation

The developmental pattern of ventilatory responses, through childhood and puberty into adulthood, is not known. Therefore we studied hypercapnic (HCVR) and hypoxic ventilatory responses (HOVR) in 59 subjects (29 males and 30 females) 4–49 yr of age, of whom 35 were children ( < 18 yr old). There was a significant correlation between HCVR and weight (r = 0.33, P < 0.02), vital capacity (r = 0.30, P < 0.05), and body surface area (r = 0.30, P < 0.05) but not height (r = 0.22, NS). There was no correlation between HOVR and any of the correcting factors. To account for disparities in body size, volume-related results were scaled for body weight. The HCVR corrected for weight (HCVR/WT) decreased with age (r = -0.57, P < 0.001). HCVR/WT was significantly higher in children than in adults (0.056 +/- 0.024 vs. 0.032 +/- 0.015 l.kg-1 x min-1. Torr end-tidal PCO2-1, P < 0.001). The (tidal volume/inspiratory duration)/weight, respiratory rate, and heart rate responses to hypercapnia were increased in the children, and the CO2 threshold was lower (36 +/- 5 vs. 40 +/- 6 Torr, P < 0.05). Similarly, the HOVR corrected for weight (HOVR/WT) decreased with age (r = 0.34, P < 0.05), and HOVR/WT was significantly higher in children than in adults (-0.035 +/- 0.017 vs. -0.024 +/- 0.016 l.kg-1 x min-1.% arterial O2 saturation-1, P < 0.02). The respiratory rate and heart rate responses to hypoxia were increased in the children. We conclude that rebreathing HCVR and HOVR are higher during childhood than during adulthood.

scholarly journals Changes in Respiratory Rate, Blood Pressure and Heart Rate Variability in Rabbits during Orthostasis

2006 ◽  
Vol 75 (1) ◽  
pp. 3-12 ◽  
Author(s):  
J. Mokrý ◽  
T. Remeňová ◽  
K. Javorka
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Heart Rate Variability ◽  
Respiratory Rate ◽  
Supine Position ◽  
Spectral Power ◽  
Systemic Blood Pressure ◽  
Microcomputer System ◽  
Systemic Blood ◽  
Frequency Bands

The purpose of the study was to evaluate the changes of respiratory rate, systemic blood pressure and heart rate variability parameters (HRV) during orthostasis in anaesthetized rabbits. Furthermore, these changes were influenced by affecting the renin-angiotensin-aldosterone (RAA) system and autonomic nervous system (ANS) to study the mechanisms participating in activity of spectral frequency bands of HRV in rabbits. Ten adult rabbits (Chinchilla) were anaesthetized by ketamine and flunitrazepam. The systemic blood pressure, tidal volume and respiratory rate were measured. HRV was evaluated by microcomputer system VariaPulse TF3E. The R-R intervals were derived from the electrocardiogram signal from subcutaneous needle electrodes. The evaluation of HRV in very low (VLF; 0.01-0.05 Hz), low (LF; 0.05-0.15 Hz) and high frequency bands (HF; 0.15-2.0 Hz) was made and parameters of frequency and time analysis were calculated. The measurements were made in horizontal (supine) position, in orthostasis (the angle of 60 °) and again in supine position before and after enalapril (0.5 mg/kg b.w.), metipranolol (0.2 mg/kg b.w.), and after subsequent bilateral cervical vagotomy. The orthostasis in anaesthetized rabbits is accompanied by depression of respiratory rate reversed only by vagotomy. Furthermore, decrease of systemic blood pressure, unchanged heart rate and increased characteristics of heart rate variability were found, with predominant increase of spectral power in LF and VLF bands. This elevation can be eliminated only by complete blockade of ANS. Although the participation of ANS or RAA system in modification of individual HRV frequency bands is not as specific as in humans, we confirmed the participation of RAA system in determination of the VLF band.

Psychophysiologic responses of mechanically ventilated patients to music: a pilot study

1995 ◽  
Vol 4 (3) ◽  
pp. 233-238 ◽  
Author(s):  
LL Chlan
Keyword(s):  
Heart Rate ◽  
Respiratory Rate ◽  
Repeated Measures ◽  
Mood States ◽  
Profile Of Mood States ◽  
Music Listening ◽  
Mechanically Ventilated ◽  
Mechanically Ventilated Patients ◽  
Over Time ◽  
Ventilated Patients

BACKGROUND: Although mechanically ventilated patients experience numerous stressors, they have not been included in music therapy stress reduction and relaxation studies. OBJECTIVE: To examine selected psychophysiologic responses of mechanically ventilated patients to music. METHODS: A two-group experimental design with pretest, posttest, and repeated measures was used. Twenty mechanically ventilated patients were randomized to a music-listening group or a nonmusic (headphones only) group. Physiologic dependent measures--heart rate and rhythm, respiratory rate, systolic and diastolic blood pressure, oxygen saturation, and airway pressure--were collected at timed intervals. Psychologic data were collected before and after intervention using the Profile of Mood States. RESULTS: Using repeated measures analysis of variance, results for heart rate and respiratory rate over time and over time between groups were significant. Between-group differences were significant for respiratory rate. Significant differences were found via t test for the music group's Profile of Mood States scores. No adverse cardiovascular responses were noted for either group. CONCLUSIONS: Data indicated that music listening decreased heart rate, respiratory rate, and Profile of Mood States scores, indicating relaxation and mood improvement.

Comparison of effects of exercise and hyperventilation on leukocyte kinetics in humans

1993 ◽  
Vol 75 (6) ◽  
pp. 2425-2428 ◽  
Author(s):  
M. S. Fairbarn ◽  
S. P. Blackie ◽  
R. L. Pardy ◽  
J. C. Hogg
Keyword(s):  
Heart Rate ◽  
Respiratory Rate ◽  
Minute Ventilation ◽  
Mechanical Effect ◽  
Blood Samples ◽  
Healthy Men ◽  
Wbc Count ◽  
End Tidal ◽  
Isocapnic Hyperpnea ◽  
End Tidal Co2

The circulating leukocyte (WBC) count increases with exercise, because WBCs enter the circulation from the marginated pool. The lung is a major source of the demarginating cells, but it is unclear whether this occurs because of increased ventilatory movements, increased cardiac output, or both. The present study examined the mechanical effect of ventilation (VE) in six healthy men with three different protocols on three separate occasions. First, the subjects cycled for 5-min intervals at 50, 100, 150, and 200 W, and we measured heart rate (HR), minute ventilation (VE), tidal volume (VT), respiratory rate, and end-tidal CO2. Second, each subject reproduced his exercise VE by matching VT, respiratory rate, and end-tidal CO2 on a circuit designed for isocapnic hyperpnea (matched VE). The subjects then performed a hyperventilation (hyper-VE) protocol with a minimum VT of 1.5 liters and a respiratory rate of 20 breaths/min. Blood samples were drawn at rest and throughout each protocol for measurement of WBCs, hematocrit, and band cells. During cycling, VE increased (9 +/- 1 to 66 +/- 7 l/min), HR increased (71 +/- 7 to 172 +/- 10 beats/min), and WBCs increased (5.5 +/- 0.9 to 7.8 +/- 1.3 x 10(9)/l). During matched VE, VE increased (11 +/- 2 to 69 +/- 11 l/min), but neither HR nor WBCs increased (67 +/- 13 to 78 +/- 12 beats/min and 5.3 +/- 1.6 to 5.7 +/- 1.5 x 10(9)/l, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Evaluation of the cardiorespiratory effects of the alpha-2 adrenoceptor agonists xylazine, medetomidine and dexmedetomidine in combination with ketamine in dogs

2018 ◽  
Vol 63 (No. 12) ◽  
pp. 546-554
Author(s):  
O. Guzel ◽  
D.A. Kaya ◽  
K. Altunatmaz ◽  
G. Sevim ◽  
D. Sezer ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Heart Rate ◽  
Oxygen Saturation ◽  
Respiratory Rate ◽  
Blood Gas ◽  
End Tidal Carbon Dioxide ◽  
Adrenoceptor Agonists ◽  
Blood Gas Parameters ◽  
Carbon Dioxide Levels ◽  
End Tidal

In this study, we compared the effects of xylazine, medetomidine and dexmedetomidine in combination with ketamine on heart rate, respiratory rate, blood gas values, temperature and sedation scores. A total of 30 dogs were evaluated. The dogs were randomly allocated into three anaesthesia groups, each of which included ten dogs. The first group, denoted the xylazine/ketamine group, intravenously received xylazine (0.5 mg/kg) for premedication and ketamine (5 mg/kg) for induction. The second group, the medetomidine/ketamine group, intravenously received medetomidine (10 µg/kg) followed by ketamine (5 mg/kg). The third group received the dexmedetomidine/ketamine combination. This group intravenously received dexmedetomidine (3 µg/kg) for premedication and ketamine (5 mg/kg). Heart rate, respiratory rate, oxygen saturation, blood gas parameters and temperature were recorded for all patients immediately before sedation onset (T<sub>0</sub>), five minutes after sedation onset (T<sub>1</sub>) and five minutes after endotracheal intubation following ketamine injection (T<sub>2</sub>). The end tidal carbon dioxide level was recorded at T<sub>2</sub>. A significant decrease in heart rate occurred following premedication in all groups. However, the decrease was most marked in the medetomidine/ketamine group. An increase was observed in venous partial pressure of carbon dioxide values at T<sub>2</sub> in the xylazine/ketamine group compared to the medetomidine/ketamine and dexmedetomidine/ketamine groups. The end tidal carbon dioxide levels were higher in the medetomidine/ketamine group than in the other two groups, and oxygen saturation of haemoglobin levels in the same group were found to be lower than in the others. It was determined that none of α<sub>2</sub>-agonists, namely xylazine, medetomidine or dexmedetomidine, had superior properties over the others. If medetomidine is used, special care should be taken because of the rapid decrease in heart rate.

scholarly journals Effect of a neck compression collar on cardiorespiratory and cerebrovascular function in postural orthostatic tachycardia syndrome (POTS)

2020 ◽  
Vol 128 (4) ◽  
pp. 907-913
Author(s):  
Massimo Nardone ◽  
Juan Guzman ◽  
Paula J. Harvey ◽  
John S. Floras ◽  
Heather Edgell
Keyword(s):  
Heart Rate ◽  
Blood Flow ◽  
Respiratory Rate ◽  
Postural Orthostatic Tachycardia Syndrome ◽  
Brain Blood Flow ◽  
Deep Breathing ◽  
Main Effect ◽  
End Tidal ◽  
Orthostatic Symptoms ◽  
Upright Tilt

Postural orthostatic tachycardia syndrome (POTS) is accompanied by reduced brain blood flow, autonomic dysfunction, and orthostatic intolerance. We hypothesized that wearing a neck compression collar would attenuate orthostatic symptoms, increase brain blood flow, and influence autonomic reflexes. Ten participants with POTS (9 women, age: 36 ± 10) underwent two trials of supine rest, paced deep breathing (6 breaths/min), Valsalva maneuver (40 mmHg for 15 s), and 70° upright tilt. For one trial, participants wore a neck compression device (Q30 Innovations). Blood pressure, heart rate (HR), brain blood flow velocity, stroke volume, respiratory rate, and end-tidal gases were continuously measured. The Vanderbilt Orthostatic Symptom Score was compiled at the end of tilt. The use of the collar reduced the orthostatic symptom score of participants with POTS during upright tilt (26.9 ± 12.5 to 18.7 ± 13.1, P = 0.04). Collar compression in the supine condition reduced the low-frequency domain of HR variability (60 ± 18 to 51 ± 23 normalized units, P = 0.04) and increased the change in HR (15 ± 5 to 17 ± 6 bpm, P = 0.02) and E:I ratio (1.2 ± 0.1 to 1.3 ± 0.1, P = 0.01) during paced deep breathing. Throughout tilt, wearing the collar reduced respiratory rate (baseline: 13 ± 3 to 12 ± 4 breath/min; tilt: 18 ± 5 to 15 ± 5 breath/min; main effect of collar P = 0.048), end-tidal oxygen (baseline: 115 ± 5 to 112 ± 5 mmHg; tilt: 122 ± 10 to 118 ± 11 mmHg; main effect of collar P = 0.026). In participants with POTS, wearing the Q-collar reduced orthostatic symptoms, increased the HR response to deep breathing, and decreased resting ventilation. NEW & NOTEWORTHY We found that using a neck compression collar alleviated orthostatic symptoms in upright posture in participants with postural orthostatic tachycardia syndrome (POTS). This could be due to compression of the baroreceptors and subsequent changes in autonomic function. Indeed, we observed increased heart rate responsiveness to paced deep breathing and reductions of respiratory rate and end-tidal O2 (suggesting reduced ventilation). Further, wearing the collar reduced mean blood velocity in the brain during Valsalva perhaps due to higher brain blood volume.

Can Non-Invasive Capnography and Integrated Pulmonary Index Contribute to Patient Monitoring in the Pediatric Emergency Department?

2021 ◽  
Author(s):  
Ramazan Gurlu ◽  
Ozlem Tolu Kendir ◽  
Omer Baspinar ◽  
Nilgun Erkek
Keyword(s):  
Emergency Department ◽  
Heart Rate ◽  
Emergency Room ◽  
Respiratory Rate ◽  
Large Scale ◽  
Pediatric Emergency ◽  
Pediatric Emergency Department ◽  
Life Saving ◽  
Significant Difference ◽  
End Tidal

Abstract Objectives Noninvasive capnography (NICG) devices can measure oxygen saturation, end-tidal carbon dioxide (EtCO2), respiratory rate, heart rate values and integrated pulmonary index (IPI). This study aimed to evaluate patients who were monitored using NICG for various indications in a pediatric emergency department and to determine its contribution to patient management in the pediatric emergency department (PED). Methods In this study, children aged <18 years who had been monitored with a NICG at the PED in our university between August 2018-May 2019 were evaluated. Of them 48 patients' file records and monitored capnography parameters such as heart rate, respiratory rate, blood pressure, capillary refill time, Glasgow Coma Score, SpO2, EtCO2, IPI recorded in the forms were reviewed. Results Patients most often presented to the emergency room due to seizures (35.4%), change in consciousness (22.9%), other neurological reasons (18.8%) with %50 were female. Seizure treatment(16.7%), circulatory–respiratory support(16.7%), and antiedema treatments(6.3%) were required for 39.5% patients as life-saving interventions, and 72.9% patients were hospitalized. Patients with low IPI(<8) values at the beginning and decreasing IPI (<8) measurements within monitoring period needed more life-saving treatments(p=0.005 and p=0.001, respectively). Low IPI values of the patients during monitoring showed a significant difference in the decision to be hospitalized(p=0.048). Conclusions The results of the present study indicate that monitoring with NICG in the pediatric emergency room can be an important early indicator in establishing clinical prediction. The study particularly points out that the IPI value can be a guide in decisions regarding life-saving treatment and hospitalization. Among the capnographic data of these patients who had a change in consciousness IPI values those measured at the beginning and within the monitorizarion period showed a significant correlation with low GCS (<8) (r=0.478, p=0.001 and r=0.456, p=0.02, respectively). Prospective comprehensive large scale studies are needed to examine the use of NICG and IPI in routine PED practice for various indications.

Contrasting effects of isocapnic and hypocapnic hyperventilation on orthostatic circulatory control

2008 ◽  
Vol 105 (4) ◽  
pp. 1069-1075 ◽  
Author(s):  
Roland D. Thijs ◽  
Joost G. van den Aardweg ◽  
Robert H. A. M. Reijntjes ◽  
J. Gert van Dijk ◽  
Johannes J. van Lieshout
Keyword(s):  
Heart Rate ◽  
Supine Position ◽  
Healthy Subjects ◽  
Cerebral Blood Flow Velocity ◽  
Factors Affecting ◽  
Tilted Position ◽  
Circulatory Control ◽  
Head Up Tilt ◽  
End Tidal ◽  
Normal Ventilation

The effects of hyperventilation (HV) on mean arterial pressure (MAP) are variable. To identify factors affecting the MAP response to HV, we dissected the effects of hypocapnic HV (HHV) and isocapnic HV (IHV) and evaluated the effects of acute vs. prolonged HHV. In 11 healthy subjects the cardio- and cerebrovascular effects of HHV and IHV vs. normal ventilation were examined for 15 min in the supine position and also for 15 min during 60° head-up tilt. The end-tidal CO2 of the HHV condition was set at 15–20 mmHg. With HHV in the supine position, mean cerebral blood flow velocity (mCBFV) declined [95% confidence interval (CI) −43 to −34%], heart rate (HR) increased (95% CI 7 to 16 beats/min), but MAP did not change (95% CI −1 to 6 mmHg). However, an augmentation of the supine MAP was observed in the last 10 min of HHV compared with the first 5 min of HHV (95% CI 2 to 12 mmHg). During HHV in the tilted position mCBFV declined (95% CI −28 to −12%) and MAP increased (95% CI 3 to 11 mmHg) without changes in HR. With supine IHV, mCBFV decreased (95% CI −14 to −4%) and MAP increased (95% CI 1 to 13 mmHg) without changes in HR. During IHV in the tilted position MAP was further augmented (95% CI 11 to 20 mmHg) without changes in CBFV or HR. Preventing hypocapnia during HV resulted in a higher MAP, suggesting two contrasting effects of HV on MAP: hypocapnia causing vasodepression and hyperpnea without hypocapnia acting as a vasopressor.

scholarly journals Evaluation of cardiorespiratory parameters in dogs undergoing laparoscopic versus open gonadectomy with spontaneous ventilation anaesthesia: a pilot study

2020 ◽  
Vol 2 (2) ◽  
pp. 1-9
Author(s):  
Fabrizio di Virgilio ◽  
Sara Manfredini ◽  
Luca Formaggini
Keyword(s):  
Carbon Dioxide ◽  
Heart Rate ◽  
Laparoscopic Surgery ◽  
Pilot Study ◽  
Oxygen Saturation ◽  
Respiratory Rate ◽  
Spontaneous Ventilation ◽  
Invasive Technique ◽  
End Tidal Carbon Dioxide ◽  
End Tidal

This pilot study aims to compare cardiorespiratory parameters in female dogs that underwent either laparoscopic or open elective gonadectomy with spontaneous ventilation anaesthesia. Records of 77 client-owned female dogs were reviewed. Patients were divided into two groups: laparoscopic surgery (L group, n 47) and open abdominal surgery (O group, n 30). The end-tidal carbon dioxide, respiratory rate, oxygen saturation, heart rate, non-invasive arterial blood pressure and length of procedure were recorded and statistically evaluated. Once normality of the sample data has been assessed, equality between the groups was analysed with two-sample Student’s or Welch’s t-test, whether the hypothesis of variance equality, through an F-test, was verified or not. A value of p <0.05 was considered statistically significant. No statistically significant difference was found between groups regarding the end-tidal carbon dioxide, oxygen saturation, respiratory rate, heart rate, systolic and medium arterial pressure values. Mean diastolic pressure was lower in the L group. The procedure length between the two groups was statistically different: laparoscopy was shorter than open surgery. In spontaneously ventilating female dogs, the cardiorespiratory parameters evaluated seem not to be affected by the presence of pneumoperitoneum when intrabdominal pressure is kept between 8 and 10 mmHg. The pilot nature of the study and the shorter laparoscopic surgery length could bias these results. However, in the author’s opinion, these findings confirm the interest of laparoscopy and the small impact of this mini-invasive technique in healthy patients.

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