Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    ISSN: 1432-1238
    Keywords: Key words Compliance ; Overinflation ; Recruitment ; Derecruitment ; Alveolar collapse ; Slice method
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Objective: Adaptation of ventilator settings to the individual's respiratory system mechanics requires information about the pressure-volume relationship and the change of compliance which is dependent on inflated volume. Unfortunately, established methods of obtaining this information are invasive and time-consuming, and, therefore, not well suited for clinical routine. We propose a new standardized diagnostic concept based on the recently developed slice method. This multiple linear regression method (MLR) determines volume-dependent respiratory system compliance (CSLICE) within the tidal volume (VT) during ongoing mechanical ventilation. The impact of a ventilator strategy, recommended by a consensus conference, on the course of compliance within VT was investigated in patients with the acute respiratory distress syndrome (ARDS) or acute lung injury (ALI).¶Design: Prospective observational study.¶Setting: Intensive care unit of a university hospital.¶Patients: 14 ARDS patients, 2 patients with ALI.¶Interventions: None.¶Measurements and results: After measurement of flow and airway pressure and calculation of tracheal pressure, CSLICE was determined. The resulting course of CSLICE within VT was estimated using a mathematical algorithm. CSLICE data were compared to those obtained by standard MLR. We found decreasing CSLICE mainly in the upper part of VT in all patients. In 7 patients, we found an additional increasing CSLICE mainly in the lower part of VT.¶Conclusions: CSLICE was not constant in patients with ARDS/ALI whose lungs were ventilated according to consensus conference recommendations. The proposed diagnostic concept may serve as a new tool to obtain a standardized estimation of respiratory system compliance within VT non-invasively without interfering with ongoing mechanical ventilation.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1432-1238
    Keywords: Lipopolysaccharide ; Liver ; Small intestinal serosa and mucosa ; Tissue oxygen tension ; Acid-base balance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Objective Study on simultaneous O2 supply/uptake relationships in liver and gut during endotoxaemia, to determine whether signs of dysoxia develop uniformly in the splanchnic region. Design Animal study to assess the early effects of endotoxaemia on oxygenation of both liver and small intestine. Interventions Eight anaesthetized pigs received a continuous portal venous infusion of lipopolysaccharide (0.5 μg·kg−1·h−1) for 6 h. Systemic, pulmonary and splanchnic haemodynamics as well as systemic and splanchnic O2 supply/uptake relationships were determined. Results There was a multiphasic haemodynamic response pattern characterized by an early (within the 1st h) and a subsequent more prolonged phase (between the 2nd and 6th h) of decreases and recovery of hepatic arterial, portal venous and superior mesenteric arterial blood flows (electromagnetic flow probes) and splanchnic O2 deliveries. Unrelated to perfusion pressure and O2 delivery, there were early and sustained decreases in ileal mucosal surface partial pressure of oxygen (PO2) (multiwire PO2 electrode) and pH (tonometry). This was not reflected by ileal serosal surface PO2, O2 uptake and arteriomesenteric venous pH and partial pressure of carbon dioxide (PCO2) gradients. There was little evidence of concomitant hepatic dysoxia as evaluated by surface PO2. Conclusions The study demonstrates early and sustained regional (mucosa) intestinal hypoxia with little evidence of simultaneous hepatic dysoxia during initial endotoxaemia.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 1432-1238
    Keywords: Key words Lipopolysaccharide ; Liver ; Small intestinal serosa and mucosa ; Tissue oxygen tension ; Acid ; base balance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract   Objective:  Study on simultaneous O2 supply/uptake relationships in liver and gut during endotoxaemia, to determine whether signs of dysoxia develop uniformly in the splanchnic region. Design: Animal study to assess the early effects of endotoxaemia on oxygenation of both liver and small intestine. Interventions: Eight anaesthetized pigs received a continuous portal venous infusion of lipopolysaccharide (0.5 μg⋅kg-1⋅h-1) for 6 h. Systemic, pulmonary and splanchnic haemodynamics as well as systemic and splanchnic O2 supply/uptake relationships were determined. Results: There was a multiphasic haemodynamic response pattern characterized by an early (within the 1st h) and a subsequent more prolonged phase (between the 2nd and 6th h) of decreases and recovery of hepatic arterial, portal venous and superior mesenteric arterial blood flows (electromagnetic flow probes) and splanchnic O2 deliveries. Unrelated to perfusion pressure and O2 delivery, there were early and sustained decreases in ileal mucosal surface partial pressure of oxygen (PO2) (multiwire PO2 electrode) and pH (tonometry). This was not reflected by ileal serosal surface PO2, O2 uptake and arteriomesenteric venous pH and partial pressure of carbon dioxide (PCO2) gradients. There was little evidence of concomitant hepatic dysoxia as evaluated by surface PO2. Conclusions: The study demonstrates early and sustained regional (mucosa) intestinal hypoxia with little evidence of simultaneous hepatic dysoxia during initial endotoxaemia.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Intensive care medicine 22 (1996), S. 1155-1161 
    ISSN: 1432-1238
    Keywords: Nosocomial pneumonia ; scoring system ; Risk factors ; Intensive care units
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Objective To develop a scoring system for stratifying patients in intensive care units (ICUs) by risk of developing nosocomial pneumonia (NP), based on variables generally available in an ICU, and to determine the probability of a patient developing NP in the ICU. Design and setting A 2-year prospective cohort study conducted in a medical and surgical ICU. Patients 756 patients admitted to the ICU for 48 h or more were followed up until the development of NP or death or discharge from the ICU. Measurements and results 129 (17.1%) patients developed NP, 106 (14%) in the first 2 weeks. The following independent risk factors were identified by multivariate analysis: no infection on admission [relative risk (RR)=3.1, 95% confidence intervals (CI)=2.0 to 4.8]; thorax drainage (RR=2.1, 95% CI=1.2 to 3.5); administration of antacids (RR=2.1, 95% CI=1.4 to 3.1); partial pressure of oxygen (PO2)〉110 mmHg (RR=1.6, 95% CI=1.0 to 2.6); administration of coagulation factors (RR=1.8, 95% CI=1.0 to 3.2); male gender (RR=2.7, 95% CI=1.2 to 6.3); urgent surgery (RR=2.4, 95% CI=0.9 to 6.4); and neurological diseases (RR=4.2, 95% CI=1.9 to 9.4). To obtain a predictive risk index for NP, a scoring system was developed using a multivariate model. The probability of developing NP varied between 11.0% in the lowest risk group and 42.3% in the highest risk group. The patients' risk of acquiring NP was seven times higher in the highest score category (IV) than in the lowest one (I). Conclusions ICU patients can be stratified into high- and low-risk groups for NP. No infection on admission, thorax drainage, administration of antacids, and PO2〉110 mmHg were associated with a higher risk of NP during the entire 2-week period.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Intensive care medicine 22 (1996), S. 1155-1161 
    ISSN: 1432-1238
    Keywords: Key words Nosocomial pneumonia ; Scoring system ; Risk factors ; Intensive care units
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Objective: To develop a scoring system for stratifying patients in intensive care units (ICUs) by risk of developing nosocomial pneumonia (NP), based on variables generally available in an ICU, and to determine the probability of a patient developing NP in the ICU. Design and setting: A 2-year prospective cohort study conducted in a medical and surgical ICU. Patients: 756 patients admitted to the ICU for 48 h or more were followed up until the development of NP or death or discharge from the ICU. Measurements and results: 129 (17.1%) patients developed NP, 106 (14%) in the first 2 weeks. The following independent risk factors were identified by multivariate analysis: no infection on admission [relative risk (RR)=3.1, 95% confidence intervals (CI)=2.0 to 4.8]; thorax drainage (RR=2.1, 95% CI=1.2 to 3.5); administration of antacids (RR=2.1, 95% CI=1.4 to 3.1); partial pressure of oxygen (PO2) 〉110 mmHg (RR=1.6, 95% CI=1.0 to 2.6); administration of coagulation factors (RR=1.8, 95% CI=1.0 to 3.2); male gender (RR=2.7, 95% CI=1.2 to 6.3); urgent surgery (RR=2.4, 95% CI=0.9 to 6.4); and neurological diseases (RR=4.2, 95% CI=1.9 to 9.4). To obtain a predictive risk index for NP, a scoring system was developed using a multivariate model. The probability of developing NP varied between 11.0% in the lowest risk group and 42.3% in the highest risk group. The patients‘ risk of acquiring NP was seven times higher in the highest score category (IV) than in the lowest one (I). Conclusions: ICU patients can be stratified into high- and low-risk groups for NP. No infection on admission, thorax drainage, administration of antacids, and PO2〉110 mmHg were associated with a higher risk of NP during the entire 2-week period.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    ISSN: 1432-1238
    Keywords: Key words Automatic tube compensation (ATC) ; Inspiratory pressure support (IPS) ; Respiratory comfort
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Objective: To compare the new mode of ventilatory support, which we call automatic tube compensation (ATC), with inspiratory pressure support (IPS) with respect to perception of respiratory comfort. ATC unloads the resistance of the endotracheal tube (ETT) in inspiration by increasing the airway pressure, and in expiration by decreasing the airway pressure according to the non-linear pressure-flow relationship of the ETT. Design: Prospective randomized single blind cross-over study. Setting: Laboratory of the Section of Experimental Anaesthesiology (Clinic of Anaesthesiology; University of Freiburg). Subjects: Ten healthy volunteers. Interventions: The subjects breathed spontaneously through an ETT of 7.5 mm i. d. Three different ventilatory modes, each with a PEEP of 5 cmH2O, were presented in random order using the Dräger Evita 2 ventilator with prototype software: (1) IPS (10 cmH2O, 1 s ramp), (2) inspiratory ATC (ATC-in), (3) inspiratory and expiratory ATC (ATC-in-ex). Measurements and main results: Immediately following a mode transition, the volunteers answered with a hand sign to show how they perceived the new mode compared with the preceding mode in terms of gain or loss in subjective respiratory comfort: “better”, “unchanged” or “worse”. Inspiration and expiration were investigated separately analyzing 60 mode transitions each. Flow rates were continuously measured. The transition from IPS to either type of ATC was perceived positively, i. e. as increased comfort, whereas the opposite transition from ATC to IPS was perceived negatively, i. e. as decreased comfort. The transition from ATC-in to ATC-in-ex was perceived positively whereas the opposite mode transition was perceived negatively in expiration only. Tidal volume was 1220 ± 404 ml during IPS and 1017 ± 362 ml during ATC. The inspiratory peak flow rate was 959 ± 78 ml/s during IPS and 1048 ± 197 ml/s during ATC. Conclusions: ATC provides an increase in respiratory comfort compared with IPS. The predominant cause for respiratory discomfort in the IPS mode seems to be lung over-inflation.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 1432-1238
    Keywords: Key words Endotracheal tube ; Obstruction ; Computer simulation ; Airway resistance ; ARDS ; Passive expiration ; Time-constant
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Objective: Acute obstruction of endotracheal tubes (ETT) increases airway pressure, decreases tidal volume, increases the risk of dynamic hyperinflation by prolonging the duration of passive expiration, and prevents reliable calculation of tracheal pressure. We propose a computer-assisted method for detecting ETT obstruction during controlled mechanical ventilation. The method only requires measurement of the expiratory flow. Design: Computer simulation; prospective study in two cases; retrospective study in one case and in seven patients with the adult respiratory distress syndrome (ARDS). Setting: Laboratory of the Section of Experimental Anaesthesiology (University of Freiburg); surgical adult intensive care units in a university hospital (University of Basel) and in a university affiliated hospital (Zentralklinikum Augsburg). Patients: 3 patients with partial ETT or bronchial obstructions and 7 ARDS patients. Measurements and results: Expiratory flow was measured using a pneumotachograph and integrated to obtain expiratory volume. The time-constant of passive expiration (τ E) as a function of expired volume [τ E(VE) function] was calculated from the expiratory volume/flow curve. We investigated the τ E(VE) function of data obtained from: (1) computer simulation of mechanically ventilated homogeneous and inhomogeneous lungs intubated with ETTs of different sizes; (2) one patient with an artificial ETT obstruction of 7.5 and 25 % of the cross-sectional area of the ETT (case 1); (3) one patient with ETT obstruction due to secretions (case 2); (4) one patient with acute bronchial constriction (case 3); (5) seven ARDS patients who showed an increase in airway resistance of more than 2 cm H2O · s/l. It was found that an ETT obstruction caused an increase in τ E in early expiration (at high flow), whereas τ E in late expiration was virtually unchanged. The reason for this is the flow dependency of the increase in ETT resistance produced by ETT obstruction. Unlike ETT obstruction, an increase in pure airway resistance produced an increase in τ E throughout expiration. Conclusions: An ETT obstruction can be reliably distinguished from an increase in pure airway resistance by a characteristic pattern change in the τ E(VE) function, which can be detected easily even by an automated pattern recognition system.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Nuclear Physics, Section A 566 (1994), S. 257-268 
    ISSN: 0375-9474
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Physics
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Nuclear Physics, Section A 544 (1992), S. 467-470 
    ISSN: 0375-9474
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Physics
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Nuclear Physics, Section B 369 (1992), S. 600-654 
    ISSN: 0550-3213
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Physics
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...