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Spontaneous Breathing (spontaneous + breathing)

Distribution by Scientific Domains

Medical Sciences	75%
Life Sciences	25%

Selected Abstracts

Eine erweiterte Evaluation der Neurolept-Anästhesie für Meerschweinchen mit einer Analyse gemischt-exspiratorischer Gase während Spontanatmung.

JOURNAL OF ANIMAL PHYSIOLOGY AND NUTRITION, Issue 1-2 2004
Wirkung des Fastens auf das kardiorespiratorische System und den Metabolismus
Zusammenfassung Das beatmete Meerschweinchen wurde oft für neurophysiologische und respiratorische Studien eingesetzt. Diese Spezies ist auch für eine Evaluation künstlicher Sauerstoffträger, entwickelt aus Hämoglobin, geeignet, weil seine Sauerstoff-Hämoglobin-Bindung der des Menschen sehr ähnlich ist. Andererseits ist eine Narkose dieser Tiere wegen kardio-respiratorischer Depression mit herkömmlichen Verfahren schwierig. Bewährt hat sich die folgende intraperitoneal zu verabreichende Neurolept-Anästhesie: 0,2 mg Fentanyl (Janssen/D), 10 mg Droperidol (Janssen/D) sowie 400 mg Urethan in 10 ml isotonischer Natriumchlorid-Lösung pro kg Körpergewicht. Unser neues Tier-Modell ermöglicht, mit einem speziellen Ventilsystem den Gasaustausch unter Spontanatmung, kardiovaskuläre wie auch Blutgaswerte und damit den Säure-Basen-Status zu messen. Die vitalen Parameter der Tiere, blieben über mehr als 6 Stunden stabil und nahe bei Werten wacher Tiere, insbesondere der mittlere arterielle Blutdruck. Deswegen ist diese etablierte Neurolept-Anästhesie des Meerschweinchens für Forschungszweck zu bevorzugen. Nüchterne Tiere zeigten signifikant erniedrigte Blut-pH- (7,345 bzw. 7,401) sowie Herzfrequenz- (244 bzw. 277 min,1) und Ventilationswerte (167 bzw. 205 ml/min) im Vergleich zu nicht nüchternen Tieren. Summary An Extended Evaluation of a Neuroleptanesthesia for the Guinea Pig with Analysis of Mixed Expiratory Gases during Spontaneous Breathing. Effects of Fasting on the Cardiorespiratory System and Metabolism The artificially ventilated guinea pig was frequently used for neurophysiological and respiratory studies. This species is also preferable for an evaluation of hemoglobin based artificial oxygen carriers, because its oxygen hemoglobin binding is very similar to that of man. But the narcosis of this animal-species is very difficult, because of cardiorespiratory depression induced by conventional procedures. The following intraperitoneal administered neuroleptanesthesia was proved in guinea pigs: 0,2 mg Fentanyl (Janssen/D), 10 mg Droperidol (Janssen/D) and 400 mg Urethan in 10 ml isotonic sodium chloride solution per kg body weight. Our new animal model with a special valve system enables to assess the gas exchange under spontaneous breathing, cardiovascular and the acid-base parameters. The vital parameters of animals were stable over 6 hours and very close to those of awake animals, especially the arterial average blood pressure. For that reason, this established neuroleptanesthesia of guinea pigs is preferable for research purpose. The fasted animals show significantly decreased values of arterial blood pH (7,345 vs. 7,401), of heart frequency (244 vs. 277 min,1), and of ventilation value (167 vs. 205 ml/min) compared to non-fasted animals. [source]

Early administration of surfactant in spontaneous breathing with nCPAP: feasibility and outcome in extremely premature infants (postmenstrual age ,27 weeks)

PEDIATRIC ANESTHESIA, Issue 4 2007
ANGELA KRIBS MD
Summary Background:, Spontaneous breathing supported by nasal continuous positive airway pressure (nCPAP) is thought to have some advantages compared with mechanical ventilation in extremely premature infants. In addition, early or prophylactic surfactant administration has been shown to be superior to delayed use. A strategy to combine these two principles was tested in our neonatal intensive care unit (NICU). The aim of this feasibility study was to describe the procedure and compare short-term results with a historical control. Methods:, The study took place in a level III NICU. In the observational period all extremely premature infants with clinical signs of moderate to severe respiratory distress syndrome despite nCPAP received 100 mg·kg,1 of a natural surfactant preparation via an intratracheal catheter during spontaneous breathing. In the historical control period those infants were intubated and ventilated to receive surfactant. Results:, Twenty-nine of 42 infants fulfilled the criteria and were treated with the new approach. In five cases ventilation with manual bag was necessary after administration of surfactant but all infants could be retransferred to nCPAP within a few minutes. Ten infants were intubated later during the first 3 days. Mortality was 7% in the group of infants treated in this way and 12% in all infants treated during the observational period. Mortality was 35% in the historical control period. Morbidity was within ranges reported by other authors. Conclusions:, Surfactant administration during nCPAP is feasible. First results indicate that early complications are rare. This warrants a prospective randomized trial. [source]

Measurement of respiratory function by impulse oscillometry in horses

EQUINE VETERINARY JOURNAL, Issue 1 2004
E. Van Erck
Reasons for performing study: Due to technical implementations and lack of sensitivity, pulmonary function tests are seldom used in clinical practice. Impulse oscillometry (IOS) could represent an alternative method. Objectives: To define feasibility, methodology and repeatability of IOS, a forced oscillation technique that measures respiratory resistance (Rrs) and reactance (Xrs) from 5 to 35 Hz during spontaneous breathing, in horses. Methods: Using 38 healthy horses, Rrs and Xrs reference values were defined and influence of individual biometrical parameters was investigated. In addition, IOS measurements of 6 horses showing clinical signs of heaves were compared to those of 6 healthy horses. Results: Airtightness and minimal dead space in the facemask were prerequisites to IOS testing and standardisation of head position was necessary to avoid variations in Rrs due to modified upper airway geometry. In both healthy and diseased animals, measurements were repeatable. In standard-type breeds, the influence of the horse's size on IOS parameters was negligible. An increase in R5Hz greater than 0.10 kPa/l/sec and R5Hz>R10Hz, combined with negative values of Xrs between 5 and 20 Hz, was indicative of heaves crisis. Conclusions: IOS is a quick, minimally invasive and informative method for pulmonary function testing in healthy and diseased horses. Potential relevance: IOS is a promising method for routine and/or field respiratory clinical testing in the equine species. [source]

Eine erweiterte Evaluation der Neurolept-Anästhesie für Meerschweinchen mit einer Analyse gemischt-exspiratorischer Gase während Spontanatmung.

Respiration can be monitored by photoplethysmography with high sensitivity and specificity regardless of anaesthesia and ventilatory mode

ACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 8 2005
L. Nilsson
Background:, Photoplethysmography (PPG) is a non-invasive optical technique used, for instance, in pulse oximetry. Beside the pulse synchronous component, PPG has a respiratory synchronous variation (PPGr). Efforts have been made to utilize this component for indirect monitoring of respiratory rate and volume. Assessment of the clinical usefulness as well as of the physiological background of PPGr is required. We evaluated if anaesthesia and positive-pressure ventilation would affect PPGr. Methods:, We recorded reflection mode PPGr, at the forearm, and the respiratory synchronous changes in central venous pressure (CVP), peripheral venous pressure (PVP) and arterial blood pressure (ABP) in 12 patients. Recordings for each patient were made on three occasions: awake with spontaneous breathing; anaesthetized with spontaneous breathing; and anaesthetized with positive-pressure ventilation. We analyzed the sensitivity, specificity, coherence and time relationship between the signals. Results:, PPGr sensitivity for breath detection was [mean (SD)] >86(21)% and specificity >96(12)%. Respiratory detection in the macrocirculation (CVP, PVP and ABP) showed a sensitivity >83(29)% and specificity >93(12)%. The coherence between signals was high (0.75,0.99). The three measurement situations did not significantly influence sensitivity, specificity or time shifts between the PPGr, PVP, ABP, and the reference CVP signal despite changes in physiological data between measurements. Conclusion:, A respiratory synchronous variation in PPG and all invasive pressure signals was detected. The reflection mode PPGr signal seemed to be a constant phenomenon related to respiration regardless of whether or not the subject was awake, anaesthetized or ventilated, which increases its clinical usefulness in respiratory monitoring. [source]

Early administration of surfactant in spontaneous breathing with nCPAP: feasibility and outcome in extremely premature infants (postmenstrual age ,27 weeks)

The reliability of endtidal CO2 in spontaneously breathing children during anaesthesia with Laryngeal Mask AirwayTM, low flow, sevoflurane and caudal epidural

PEDIATRIC ANESTHESIA, Issue 5 2002
Per AASHEIM MD
Background: Noninvasive devices for monitoring endtidal CO2 (PECO2) are in common use in paediatric anaesthesia. Questions have been raised concerning the reliability of these devices in spontaneous breathing children during surgery. Our anaesthetic technique for elective infraumbilical surgery consists of spontaneous breathing through a Laryngeal Mask Airway (LMATM), low fresh gas flow, sevoflurane and a caudal epidural. We wanted to compare PECO2 and arterial CO2 (PaCO2) during surgery. Methods: Twenty children, aged 1,6 years, scheduled for infraumbilical surgery, were studied and one arterial sample was taken 45 min after induction of anaesthesia. PECO2, inspiratory PCO2, oxygen saturation, heart rate, respiratory rate, mean arterial blood pressure and expiratory sevoflurane concentration were measured every 5 min. The respiratory and circulatory parameters were stable during surgery. Results: The mean PaCO2 , PECO2 difference was 0.15 (0.16) kPa [1.1 (1.2 mmHg)]. Conclusions: PECO2 is a good indicator of PaCO2 in our anaesthetic setting. [source]

Comparison of spontaneous with controlled mode of ventilation in tonsillectomy

PEDIATRIC ANESTHESIA, Issue 2 2001
FRCA(UK), Fauzia A. Khan MB
Methods:,This randomized study compares spontaneous versus controlled ventilation in 60 ASA I and II patients undergoing tonsillectomy as regards haemodynamic stability, recovery characteristics, intra- and immediate postoperative complications and surgical impressions. Results:,The patients in the balanced anaesthesia (B) group showed less haemodynamic variability compared to baseline after tracheal intubation, mouth gag application and removal and incision. Two patients had dysrhythmias in the B group compared to six in the spontaneous breathing (S) group. Six patients in the S group had a rise in endtidal carbon dioxide concentration above 7.8 kPa (60 mmHg). Recovery scores were higher in the B group at 10 and 20 min into recovery. The surgical impression of bleeding and jaw relaxation was similar with both groups. The incidence of postoperative nausea and vomiting and agitation was higher in the S group but did not achieve statistical significance. Conclusions:,Use of balanced anaesthesia offered more haemodynamic stability and a rapid recovery. [source]

Vasomotor sympathetic neural control is maintained during sustained upright posture in humans

THE JOURNAL OF PHYSIOLOGY, Issue 2 2006
Qi Fu
Vasomotor sympathetic activity plays an important role in arterial pressure maintenance via the baroreflex during acute orthostasis in humans. If orthostasis is prolonged, blood pressure may be supported additionally by humoral factors with a possible reduction in sympathetic baroreflex sensitivity. We tested the hypothesis that baroreflex control of muscle sympathetic nerve activity (MSNA) decreases during prolonged upright posture. MSNA and haemodynamics were measured supine and during 45 min 60 deg upright tilt in 13 healthy individuals. Sympathetic baroreflex sensitivity was quantified using the slope of the linear correlation between MSNA and diastolic pressure during spontaneous breathing. It was further assessed as the relationship between MSNA and stroke volume, with stroke volume derived from cardiac output (C2H2 rebreathing) and heart rate. Total peripheral resistance was calculated from mean arterial pressure and cardiac output. We found that MSNA increased from supine to upright (17 ± 8 (s.d.) versus 38 ± 12 bursts min,1; P < 0.01), and continued to increase to a smaller degree during sustained tilt (39 ± 11, 41 ± 12, 43 ± 13 and 46 ± 15 bursts min,1 after 10, 20, 30 and 45 min of tilt; between treatments P < 0.01). Sympathetic baroreflex sensitivity increased from supine to upright (,292 ± 180 versus,718 ± 362 units beat,1 mmHg,1; P < 0.01), but remained unchanged as tilting continued (,611 ± 342 and ,521 ± 221 units beat,1 mmHg,1 after 20 and 45 min of tilt; P= 0.49). For each subject, changes in MSNA were associated with changes in stroke volume (r= 0.88 ± 0.13, P < 0.05), while total peripheral resistance was related to MSNA during 45 min upright tilt (r= 0.82 ± 0.15, P < 0.05). These results suggest that the vasoconstriction initiated by sympathetic adrenergic nerves is maintained by ongoing sympathetic activation during sustained (i.e. 45 min) orthostasis without obvious changes in vasomotor sympathetic neural control. [source]

Awake tracheal intubation using the SensascopeÔ in 13 patients with an anticipated difficult airway

ANAESTHESIA, Issue 5 2010
R. Greif
Summary We present the use of the SensaScopeÔ, an S-shaped rigid fibreoptic scope with a flexible distal end, in a series of 13 patients at high risk of, or known to have, a difficult intubation. Patients received conscious sedation with midazolam or fentanyl combined with a remifentanil infusion and topical lidocaine to the oral mucosa and to the trachea via a trans-cricoid injection. Spontaneous ventilation was maintained until confirmation of tracheal intubation. In all cases, tracheal intubation was achieved using the SensaScope. The median (IQR [range]) insertion time (measured from the time the facemask was taken away from the face until an end-expiratory CO2 reading was visible on the monitor) was 58 s (38,111 [28,300]s). In nine of the 13 cases, advancement of the SensaScope into the trachea was easy. Difficulties included a poor view associated with a bleeding diathesis and saliva, transient loss of spontaneous breathing, and difficulty in advancing the tracheal tube in a patient with unforeseen tracheal narrowing. A poor view in two patients was partially improved by a high continuous flow of oxygen. The SensaScope may be a valuable alternative to other rigid or flexible fibreoptic scopes for awake intubation of spontaneously breathing patients with a predicted difficult airway. [source]

Early surfactant in spontaneously breathing with nCPAP in ELBW infants , a single centre four year experience

ACTA PAEDIATRICA, Issue 3 2008
Angela Kribs
Abstract Objective: To evaluate whether the experience with a method to administer surfactant during spontaneous breathing with nasal continuous positive airway pressure (nCPAP) as primary respiratory support in infants with respiratory distress syndrome (RDS) influences the frequency of its use and affects the outcome of patients. Methods: All inborn extremely low birthweight (ELBW) infants treated after introduction of the method were retrospectively studied (n = 196). The entire observational period was divided into four periods (periods 1,4) and compared with a control period (period 0) (n = 51). Primary respiratory support, demographics, prenatal risks and outcomes were compared. Results: There were no changes in demographics or prenatal risks over time. The choice of nCPAP as initial airway management significantly increased from 69% to 91% and for nCPAP with surfactant from 75% to 86%. The rate of nCPAP failure decreased from 46% to 25%. Survival increased significantly between periods 0 and 1 from 76% to 90% and survival without bronchopulmonary dysplasia (BPD) rose from 65% to 80%. No changes in nonpulmonary outcomes were observed. Conclusion: The success of nCPAP increased with increasing use of nCPAP with surfactant. Simultaneously, mortality decreased without deterioration of other outcomes indicating that the use of surfactant in spontaneous breathing with nCPAP could be beneficial. [source]