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- Leiter, Robert, et al.
(author)
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Comparison of superimposed high-frequency jet ventilation with conventional jet ventilation for laryngeal surgery
- 2012
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In: British Journal of Anaesthesia. - : Elsevier BV. - 0007-0912 .- 1471-6771. ; 108:4, s. 690-697
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Journal article (peer-reviewed)abstract
- BackgroundNew ventilators have simplified the use of supraglottic superimposed high-frequency jet ventilation (SHFJVSG), but it has not been systematically compared with other modes of jet ventilation (JV) in humans. We sought to investigate whether SHFJVSG would provide more effective ventilation compared with single-frequency JV techniques.MethodsA total of 16 patients undergoing minor laryngeal surgery under general anaesthesia were included. In each patient, four different JV techniques were applied in random order for 10-min periods: SHFJVSG, supraglottic normal frequency (NFJVSG), supraglottic high frequency (HFJVSG), and infraglottic high-frequency jet ventilation (HFJVIG).Chest wall volume variations were continuously measured with opto-electronic plethysmography (OEP), intratracheal pressure was recorded and blood gases were measured.ResultsChest wall volumes were normalized to NFJVSG end-expiratory level. The increase in end-expiratory chest wall volume (EEVCW) was 239 (196) ml during SHFJVSG (P<0.05 compared with NFJVSG). EEVCW was 148 (145) and 44 (106) ml during HFJVSG and HFJVIG, respectively (P<0.05 compared with SHFJVSG). Tidal volume (VT) during SHFJVSG was 269 (149) ml. VT was 229 (169) ml (P=1.00 compared with SHFJVSG), 145 (50) ml (P<0.05), and 110 (33) ml (P<0.01) during NFJVSG, HFJVSG, and HFJVIG, respectively.Intratracheal pressures corresponded well to changes in both EEVCW and VT. All JV modes resulted in adequate oxygenation. However, PACO2was lowest during HFJVSG [4.3 (1.3) kPa; P<0.01 compared with SHFJVSG].ConclusionSHFJVSG was associated with increased EEVCW and VT compared with the three other investigated JV modes. All four modes provided adequate ventilation and oxygenation, and thus can be used for uncomplicated laryngeal surgery in healthy patients with limited airway obstruction.
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- Sütterlin, Robert, et al.
(author)
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Frequency dependence of lung volume changes during superimposed high-frequency jet ventilation and high-frequency jet ventilation
- 2014
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In: British Journal of Anaesthesia. - : Elsevier BV. - 0007-0912 .- 1471-6771. ; 112:1, s. 141-149
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Journal article (peer-reviewed)abstract
- Background. Superimposed high-frequency jet ventilation (SHFJV) has proved to be safe and effective in clinical practice. However, it is unclear which frequency range optimizes ventilation and gas exchange. The aim of this study was to systematically compare high-frequency jet ventilation (HFJV) with HFJV by assessing chest wall volume variations (Delta EEVCW) and gas exchange in relation to variable high frequency. Methods. SHFJV or HFJV were used alternatively to ventilate the lungs of 10 anaesthetized pigs (21-25 kg). The low-frequency component was kept at 16 min(-1) in SHFJV. In both modes, high frequencies ranging from 100 to 1000 min(-1) were applied in random order and ventilation was maintained for 5 min in all modalities. Chest wall volume variations were obtained using opto-electronic plethysmography. Airway pressures and arterial blood gases were measured repeatedly. Results. SHFJV increased Delta EEVCW compared with HFJV; the difference ranged from 43 to 68 ml. Tidal volume (V-T) was always >240 ml during SHFJV whereas during HFJV ranged from 92 ml at theventilation frequency of 100 min(-1) to negligible values at frequencies >300 min(-1). We observed similar patterns for Pa-O2 and Pa-CO2. SHFJV provided generally higher, frequency-independent oxygenation (Pa-O2 at least 32.0 kPa) and CO2 removal (Pa-CO2 similar to 5.5 kPa), whereas HFJV led to hypoxia and hypercarbia at higher rates (Pa-O2 < 10 kPa and Pa-CO2 > 10 kPa at f(HF) > 300 min(-1)). Conclusions. In a porcine model, SHFJV was more effective in increasing end-expiratory volume than single-frequency HFJV, but both modes may provide adequate ventilation in the absence of airway obstruction and respiratory disease, except for HFJV at frequencies >= 300 min(-1).
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