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- Enekvist, Bruno
(författare)
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Abstracts.
- 2011
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Ingår i: Acta Anaesthesiologica Scandinavica. - : Wiley. - 0001-5172. ; 55:9, s. 1152-1152
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Tidskriftsartikel (refereegranskat)
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- Enekvist, Bruno
(författare)
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Influence of tidal volume on pulmonary gas exchange during general anaesthesia
- 2011
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background and objective: General anaesthesia impairs respiratory function. The present studies were performed to compare arterial concentration of sevoflurane, oxygen and carbon dioxide in normal and overweight patients ventilated with increased tidal volume (VT), or normal tidal volume with and without PEEP. Methods: Prospective, randomised, clinical studies. ASA І and II abdominal surgery patients were randomly assigned to be ventilated with normal VT (NVT) with and without PEEP to 10 cmH2O or with increased VT (IVT) achieved by increasing inspired plateau pressure 0.04 cm H2O kg-1. Extra apparatus dead space was added to maintain PETCO2 at 4.5 kPa. Arterial oxygenation, sevoflurane tension (Pasevo, Fisevo, PETsevo), PaCO2, PETCO2, stroke volume, cardiac output, VT and airway pressure were measured. Results: The groups of patients compared were similar regarding gender, age, and BMI. Arterial oxygen and sevoflurane tension was generally higher in the IVT group (P < 0.05) whereas mean FiO2 and PETsevo did not differ between the groups. Arterial carbon dioxide was significantly lower with IVT than NVT ventilated without PEEP but in the presence of PEEP in the NVT group, the groups were similar. Cardiac output decreased significantly less in the IVT group compared to the NVT group with PEEP (5 and 33 % respectively). Conclusion: Isocapnic ventilation with larger tidal volumes maintained with added apparatus dead-space increases the arterial oxygen and sevoflurane tension as well as carbon dioxide elimination in normal and overweight patients, and in overweight patient also preserves cardiac output better than in the presence of PEEP.
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- Enekvist, Bruno, et al.
(författare)
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Larger tidal volume increases sevoflurane uptake in blood: a randomized clinical study
- 2010
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Ingår i: Acta Anaesthesiologica Scandinavica. - : Wiley. - 0001-5172. ; 54:9, s. 1111-1116
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Tidskriftsartikel (refereegranskat)abstract
- Background The rate of uptake of volatile anesthetics is dependent on alveolar concentration and ventilation, blood solubility and cardiac output. We wanted to determine whether increased tidal volume (V-T), with unchanged end-tidal carbon dioxide partial pressure (PETCO2), could affect the arterial concentration of sevoflurane. Methods Prospective, randomized, clinical study. ASA physical status 2 and II patients scheduled for elective surgery of the lower abdomen were randomly assigned to one of the two groups with 10 patients in each: one group with normal V-T (NVT) and one group with increased V-T (IVT) achieved by increasing the inspired plateau pressure 0.04 cmH(2)O/kg above the initial plateau pressure. A corrugated tube added extra apparatus dead space to maintain PETCO2 at 4.5 kPa. The respiratory rate was set at 15 min-1, and sevoflurane was delivered to the fresh gas by a vaporizer set at 3%. Arterial sevoflurane tensions (P(a)sevo), F(i)sevo, P(ET)sevo, PETCO2, PaCO2, V-T and airway pressure were measured. Results The two groups of patients were similar with regard to gender, age, weight, height and body mass index. The mean P(ET)sevo did not differ between the groups. Throughout the observation time, arterial sevoflurane tension (mean +/- SE) was significantly higher in the IVT group compared with the NVT group, e.g. 1.9 +/- 0.23 vs. 1.6 +/- 0.25 kPa after 60 min of anesthesia (P < 0.05). Conclusion Ventilation with larger tidal volumes with isocapnia maintained with added dead-space volume increases the tension of sevoflurane in arterial blood.
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- Enekvist, Bruno, et al.
(författare)
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Pulse perfusion value predicts eye opening after sevoflurane anaesthesia: an explorative study.
- 2015
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Ingår i: Journal of Clinical Monitoring and Computing. - : Springer Science and Business Media LLC. - 1573-2614 .- 1387-1307. ; 29:4, s. 461-465
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Tidskriftsartikel (refereegranskat)abstract
- The variables measured in modern pulse oximetry apparatuses include a graphical pulse curve and a specified perfusion value (PV) that could be a sensitive marker for detecting differences in sympathetic activity. We hypothesized that there is a correlation between a reduction of PV and the time to eye opening after general anaesthesia. The objective was to investigate whether PV can predict eye opening after sevoflurane anaesthesia. Prospective, explorative clinical study included 20 patients, ASA physical status 1 or 2, at Skåne University Hospital, Lund, Sweden, from November 2012 to January 2013 scheduled for elective breast tumour surgery. A general anaesthesia was delivered with inhalation of oxygen, nitrous oxide and sevoflurane anaesthesia to a depth of 1.2 minimal alveolar concentration. Sevoflurane inspiratory and expiratory concentrations were measured. Bispectral index monitoring, PV as measured by pulse oximeter, heart rate and carbon dioxide were registered at before anaesthesia, 15 min after induction (at 1.2 minimal alveolar concentration), at end of surgery and at eye opening at the end of anaesthesia. PV values were lower before anaesthesia and at eye opening compared to at 15 min after induction and at end of surgery (P < 0.05). The reduction of PV between end of surgery and eye opening was 0.76. We conclude that the pulse oximeter PV could be a useful variable to assess the timing of recovery, in terms of eye opening after a general anaesthesia.
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- Enekvist, Bruno, et al.
(författare)
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Pulse perfusion values to predict eye opening after intravenous anesthesia : An explorative study
- 2016
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Ingår i: AANA Journal. - 0094-6354. ; 84:4, s. 255-259
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Tidskriftsartikel (refereegranskat)abstract
- Variables measured in modern pulse oximetry apparatuses include a graphic pulse curve and a specified perfusion value (PV) that could be a sensitive marker for detecting differences in sympathetic activity. We hypothesized that there is a correlation between a reduction of PV and the time to eye opening after anesthesia with propofol-remifentanil. This study includes 29 patients, ASA physical status 1 or 2, scheduled for elective thyroid surgery. Main outcome measures were PV measured by pulse oximetry, heart rate, and noninvasive mean arterial blood pressure recorded before anesthesia, 15 minutes after induction, and at start of surgery, end of surgery, and eye opening at the end of anesthesia. Carbon dioxide (PETCO2) and oxygen inspiratory (FI-PO2) and expiratory (FE-PO2) concentrations were measured at all times except before anesthesia. Results demonstrated that PVs before anesthesia and at eye opening were lower than 15 minutes after induction and at end of surgery (P <.05). The PETCO2 and difference of FI-PETO2 increased at eye opening compared with the end of surgery (P <.05). We conclude that the pulse oximetry PV and the increased PETCO2 could be useful variables to predict timing of recovery in terms of eye opening after intravenous anesthesia.
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- Enekvist, Bruno, et al.
(författare)
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The effect of increased apparatus dead space and tidal volumes on carbon dioxide elimination and oxygen saturations in a low-flow anesthesia system.
- 2008
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Ingår i: Journal of Clinical Anesthesia. - : Elsevier BV. - 1873-4529 .- 0952-8180. ; 20:3, s. 170-174
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Tidskriftsartikel (refereegranskat)abstract
- STUDY OBJECTIVE: To determine if a large tidal volume (V(T)), with an unchanged end-tidal carbon dioxide partial pressure (P(ET)co(2)), could improve arterial carbon dioxide elimination, oxygen saturation (Spo(2)), and arterial blood oxygenation. DESIGN: Prospective, randomized, clinical study. SETTING: Single university hospital. PATIENTS: 60 ASA physical status I and II patients scheduled for elective urologic or general surgery. INTERVENTIONS: Patients were randomly assigned to one of two treatments: patients in group 1, nondead space (NDS), received a fresh gas flow of 1 L/min without added apparatus dead space volume. Patients in group 2, dead space (DS), received ventilation using an added dead space volume between the Y-piece and tracheal tube. In both groups, patients' lungs were ventilated to a fixed P(ET)co(2) value of 33.8 mmHg. Patients in the DS group were ventilated with V(T)s to maintain an airway plateau pressure (P(plateau)) of 0.04 cm H(2)O/kg over initial plateau pressure. The corrugated tube was then adjusted to maintain a fixed P(ET)co(2). MEASUREMENTS: Dead space volumes, P(ET)co(2), arterial CO(2) tension (Paco(2)), SpO(2), arterial O(2) tension (Pao(2)), V(T)s, and airway pressures were measured. MAIN RESULTS: Arterial CO(2) tension was significantly lower in the DS group, 36 +/- 2.3 mmHg, compared with the NDS group, 37.5 +/- 2.3 mmHg (P < 0.05), and the difference between P(ET)co(2) and Paco(2) was lower in the DS group than in the NDS group (P < 0.001). Oxygen saturation was 99% +/- 1.0% in the DS group compared with 98.5% +/- 1.5% in the NDS group (P < 0.05). Arterial O(2) tension was 13.2 +/- 25.5 mmHg in the DS group and 119.1 +/- 30.2 mmHg in NDS group (not significant). CONCLUSION: Larger V(T)s, with an unchanged P(ET)CO(2) concentration created by an added apparatus dead space volume, improved arterial carbon dioxide elimination.
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- Enekvist, Bruno, et al.
(författare)
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Ventilation with increased apparatus dead space vs positive end-expiratory pressure : Effects on gas exchange and circulation during anesthesia in a randomized clinical study
- 2014
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Ingår i: AANA Journal. - 0094-6354. ; 82:2, s. 114-120
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Tidskriftsartikel (refereegranskat)abstract
- Atelectasis formation can be reduced by positive endexpiratory pressure (PEEP), but resulting increases in intrathoracic pressure could affect circulation. We have earlier demonstrated that increased tidal volumes with larger apparatus dead space improves oxygenation and sevoflurane uptake. In the present study, we hypothesize that isocapnic ventilation with increased tidal volumes increases oxygen and sevoflurane uptake similar to ventilation with PEEP, but with less impact on cardiac output. Thirty patients, with ASA physical status 1 or 2, scheduled for elective open colon surgery were randomly assigned to be ventilated with either PEEP at 10 cm H2O (PEEP, 15 patients) or increased tidal volumes achieved with larger apparatus dead space but with zero end-expiratory pressure (DS group, 15 patients). Oxygen tension and arterial sevoflurane concentration were significantly higher in the DS group (P < .05). Cardiac output decreased significantly less in the DS group compared with the PEEP group (5% and 33%, respectively; P < .05). Consequently, isocapnic ventilation with increased tidal volumes using apparatus dead space increased oxygen and sevoflurane tensions in arterial blood and preserved cardiac output better than did PEEP.
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