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Spontaneous Ventilation (spontaneous + ventilation)
Selected AbstractsAwake tracheal intubation using the SensascopeÔ in 13 patients with an anticipated difficult airwayANAESTHESIA, Issue 5 2010R. 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] Clinical application of continuous spirometry with a pitot-based flow meter during equine anaesthesiaEQUINE VETERINARY EDUCATION, Issue 7 2010Y. P. S. Moens Summary This report documents the feasibility and clinical information provided by a new method for spirometric monitoring adapted for equine anaesthesia. Monitoring of ventilatory function was done with continuous spirometry during general anaesthesia of client-owned horses presented for various diagnostic and surgical procedures. An anaesthetic monitor with a spirometry unit for human anaesthesia was used. To allow the measurement of large tidal volumes, a remodelled larger version of the pitot tube- based flow sensor was used. This technology provided reliable spirometric data even during prolonged anaesthesia when water condensation accumulated in the anaesthetic circuit and the sensor. In addition to flow and volume measurement and respiratory gas analysis, the continuous display of flow-volume and pressure-volume loops offered visually recognisable information about compliance, airway resistance and integrity of the circuit. Continuous spirometry with this monitoring system was helpful in evaluating the efficacy of spontaneous ventilation, in adjusting intermittent positive pressure ventilation and detecting technical faults in the anaesthetic apparatus and connection with the patient. This adapted spirometry method represents a practical and reliable measuring system for use during equine anaesthesia. The variety of information provides an opportunity to optimise anaesthetic management in this species. [source] The Use of Cerebral Oximetry as a Monitor of the Adequacy of Cerebral Perfusion in a Patient Undergoing Shoulder Surgery in the Beach Chair PositionPAIN PRACTICE, Issue 4 2009Gregory W. Fischer MD Abstract Four cases of ischemic injury have been reported in patients undergoing orthopedic surgery in the upright position. We describe the use of cerebral oximetry as a monitor of the adequacy of cerebral perfusion in a 63-year-old woman who underwent arthroscopic rotator cuff surgery in a beach chair under general anesthesia. During positioning, a decrease in blood pressure was accompanied by a decrease in cerebral oxygen saturation (SctO2) and was treated with phenylephrine. When spontaneous ventilation resumed, an increase in end-tidal carbon dioxide was accompanied by an increase in SctO2. Cerebral oximetry may prove useful as a guide monitor and manage nonsupine patients. [source] A simple method to reduce the inspiratory oxygen fraction for high pulmonary blood flow patients in an operating roomPEDIATRIC ANESTHESIA, Issue 12 2007AYAKO ASAKURA MD Summary Background:, Low inspired oxygen acutely increases pulmonary vascular resistance and decreases pulmonary-systemic blood flow ratio. We present a simple method to lower inspired oxygen fraction (FIO2 < 0.21) without supplemental nitrogen, during mechanical ventilation by an anesthesia machine. Methods:, After institutional approval, seven healthy adult volunteers and three infants (0,12 month old) scheduled for congenital heart surgery were enrolled in this study. All the infants were diagnosed with congestive heart failure because of high pulmonary blood flow and were thought to benefit from low FIO2. The volunteers performed spontaneous ventilation (fresh air flow rate = 10 l·min,1, tidal volume = 600 ml, frequency = 10 br·min,1). The infants were mechanically ventilated with air (fresh air flow rate = 6 l·min,1, tidal volume = 10 ml·kg,1, 15 < frequency < 30 br·min,1 to adjust PaCO2 between 5.8 kPa and 6.5 kPa (45,50 mmHg), after induction of general anesthesia and tracheal intubation. The fresh gas flow rates were determined by the following formula. Fresh gas flow rate = (FIO2 , FEO2) EVE/(0.21 + FIO2 , FEO2 , target FIO2). We recorded FIO2 every 5 min for 30 min. When arterial oxygen saturation decreased >15%, fresh gas flow rates were increased to adjust FIO2 to 0.21. Results:, In all of the seven volunteers and three infants target FIO2 was achieved in <10 min. FIO2 was kept at 0.18 ± 0.01 (SD) by calculated fresh air flow rates. In one infant, SpO2 decreased >15% 20 min after lowering FIO2, we had to discontinue this study, and increase fresh gas flow to ventilate the infant with FIO2 0.21. In the other two infants, FIO2 was maintained throughout the study. Conclusions:, This simple and convenient method to decrease FIO2, has a utility in clinical situations, in which pulmonary vascular resistance is to be increased to improve systemic oxygen delivery in patients with high pulmonary blood flow during cardiac surgery. [source] Management of congenital tracheal stenosis , using spontaneous ventilation to facilitate cardiopulmonary bypassPEDIATRIC ANESTHESIA, Issue 4 2006KATHERINE TAYLOR FANZCA Summary We present an unusual case of an infant with life-threatening tracheal stenosis scheduled for repair utilizing cardiopulmonary bypass. After repeated attempts at intubation endtidal CO2 was absent. The child was eventually managed with spontaneous breathing sevoflurane via a facemask. The possible causes of absent endtidal CO2 after intubation are discussed. [source] EMLA® Cream coated on the rigid bronchoscope for tracheobronchial foreign body removal in childrenTHE LARYNGOSCOPE, Issue 1 2009Hai Yu MD Abstract Objectives: Removal of a tracheal or bronchial foreign body is a common emergent surgical procedure in children. The anesthetic management can be challenging. EMLA® Cream (EC) has been widely used to provide topical anesthesia. In the present study, we evaluate the efficacy and safety of EC coated on the rigid bronchoscope for tracheobronchial foreign body removal in children undergoing intravenous anesthesia with spontaneous ventilation. Study Design: The authors conducted a randomized, double-blind, placebo-controlled clinical trial. Methods: Thirty patients were randomized to receive either EC or placebo (lubricant ointment) coated on the rigid bronchoscope. Intravenous anesthesia and spontaneous ventilation were performed in all patients. Heart rate, blood pressure, pulse oxygen saturation (SpO2) and frequency and degree of breath holding were recorded. After surgery, the bronchoscopist rated overall surgical manipulation as excellent, fair, and poor. The durations of postoperative care were also recorded. Results: Episodes of oxygen desaturation (SpO2 < 90%) occurred in 3/15 (20%) patients in the EC group and in 9/15 (60%) patients in the control group (P < .05). Occurrences and degrees of breath holding were less in the EC group than that in the control group (P < .05). Ranks of surgical manipulation were excellent in 80% of patients in the EC group versus 13% of patients in the control group (P < .05). The durations of postoperative care were shorter in the EC group than that in the control group (P < .05). Conclusions: EC coated on the rigid bronchoscope combined with intravenous anesthesia could provide more efficacious and safer anesthesia for tracheobronchial foreign body removal in children under spontaneous ventilation. Laryngoscope, 119:158,161, 2009 [source] Ketamine or alfentanil administration prior to propofol anaesthesia: the effects on ProSealÔ laryngeal mask airway insertion conditions and haemodynamic changes in childrenANAESTHESIA, Issue 3 2009Z. Begec Summary This study was designed to compare the effects of ketamine and alfentanil administered prior to induction of anaesthesia with propofol, on the haemodynamic changes and ProSeal laryngeal mask airway® (PLMA) insertion conditions in children. Eighty children, aged between 3,132 months, were randomly allocated to receive either alfentanil 20 ,g.kg,1 (alfentanil group) or ketamine 0.5 mg.kg,1 (ketamine group) before induction of anaesthesia. Ninety seconds following the administration of propofol 4 mg.kg,1, a PLMA was inserted. In the ketamine group, heart rate and mean arterial pressure were higher during the study period compared with the alfentanil group (p < 0.05). The time for the return of spontaneous ventilation was prolonged in the alfentanil group (p = 0.004). In conclusion, we found that the administration of ketamine 0.5 mg.kg,1 with propofol 4 mg.kg,1 preserved haemodynamic stability, and reduced the time to the return of spontaneous ventilation, compared with alfentanil 20 ,g.kg,1 during PLMA placement. In addition, the conditions for insertion of the PLMA with ketamine were similar to those found with alfentanil. [source] DOSE,RESPONSE OF ROPIVACAINE ADMINISTERED CAUDALLY TO CHILDREN UNDERGOING SURGICAL PROCEDURES UNDER SEDATION WITH MIDAZOLAMCLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, Issue 7 2004F Tonatiu Aguirre-Garay SUMMARY 1.,In a double-blind randomized controlled design, 50 children were allocated to receive bupivacaine 0.25% or ropivacaine 0.25%, 0.32%, 0.40% or 0.50% by caudal block. 2.,Caudal block was performed after induction of anaesthesia with 2,5% sevoflurane, atropine 10 µg/kg and midazolam 100,300 µg/kg. During the surgical procedure, patients were maintained under spontaneous ventilation and no intravenous or inhalatory anaesthetic agent was administered. For transoperative sedation, midazolam 100,300 µg/kg was administered every 0.5,1.0 h. Transoperative cardiovascular response, postoperative analgesia and local and systemic complications were evaluated. 3.,Groups were similar (P > 0.05) in sex, age, weight and in the time elapsed from caudal block to the beginning of the surgical procedure. The surgical time was significantly lower in the ropivacaine 0.25% group. The duration of analgesia was 24 h with ropivacaine 0.25% and approximately 10 h in the other four groups (P < 0.001). Linear regression analysis revealed a significant relationship between the postoperative analgesic period produced by ropivacaine and the surgical time (r = , 0.48, two-sided P = 0.002). Systolic and diastolic blood pressures remained in the physiologically normal range for the duration of the transoperative period. Vomiting was present in only one patient receiving ropivacaine 0.50%. 4.,In children, the duration of analgesia produced by caudal block with ropivacaine may be affected by surgical time. At surgical times of 0.5,1 h, ropivacaine 0.25% produced at least 24 h postoperative analgesia. At similar surgical times, ropivacaine 0.32%, 0.40% and 0.50% produced similar analgesic times to bupivacaine 0.25%. [source] Regional cerebral blood flow during hyperventilation in patients with acute bacterial meningitisCLINICAL PHYSIOLOGY AND FUNCTIONAL IMAGING, Issue 5 2000K. Møller Mechanical hyperventilation is often instituted in patients with acute bacterial meningitis when increased intracranial pressure is suspected. However, the effect on regional cerebral blood flow (CBF) is unknown. In this study, we measured regional CBF (rCBF) in patients with acute bacterial meningitis before and during short-term hyperventilation. In 17 patients with acute bacterial meningitis, absolute rCBF (in ml/100 g min,1) was measured during baseline ventilation and hyperventilation by single-photon emission computed tomography (SPECT) using intravenous 133Xe bolus injection. Intravenous 99mTc-HMPAO (hexamethylpropyleneamine oxime) was subsequently given during hyperventilation. In 12 healthy volunteers, rCBF was measured by SPECT and 99mTc-HMPAO during spontaneous ventilation. Using standard templates to identify regions of interest (ROIs), we calculated rCBF in percentage of cerebellar (99mTc-HMPAO images) or mean hemispheric (133Xe images) flow for each ROI, the degree of side-to-side asymmetry for each ROI, and the anterior-to-posterior flow ratio. On 133Xe images, absolute rCBF decreased significantly during hyperventilation compared to baseline ventilation in all regions, but the relative rCBF did not change significantly from baseline ventilation (n=14) to hyperventilation (n=12), indicating that the perfusion distribution was unchanged. On 99mTc-HMPAO images (n=12), relative rCBF and the anterior-to-posterior flow ratio were significantly lower in patients than in controls in the frontal and parietal cortex as well as in the basal ganglia. Focal perfusion abnormalities were present in 10 of 12 patients. Regional cerebral blood flow abnormalities are frequent in patients with acute bacterial meningitis. Short-term hyperventilation does not enhance these abnormalities. [source] | ||||||||||