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Invasive Ventilation (invasive + ventilation)

Distribution by Scientific Domains

Medical Sciences	100%

Selected Abstracts

Passage of pathogenic microorganisms through breathing system filters used in anaesthesia and intensive care

ANAESTHESIA, Issue 7 2010
D. H. T. Scott
Summary Invasive ventilation poses a risk of respiratory infection that can be drug-resistant. One means of reducing transmission of infection is the use of a breathing system filter. Filters are intended to be used with dry gas. Current international standards do not require that filters prevent bacterial transfer when wet. It is not known whether microorganisms pass through wet filters, but theory predicts that this might occur. We tested six filters from three different manufacturers. We passed a suspension of microorganisms through the filters using the least pressure necessary, and incubated a sample of the filtrate on blood agar. All the filters tested allowed free passage of both Candida albicans and coagulase-negative staphylococci. The median (IQR [range]) pressure required for fluid to flow across the filter varied greatly between different filter types (20 (0,48 [0,138]) cmH2O). We conclude that even large microorganisms pass across moist breathing system filters in conditions that are found in clinical practice. [source]

Physician attitudes towards ventilatory support for spinal muscular atrophy type 1 in Australasia

JOURNAL OF PAEDIATRICS AND CHILD HEALTH, Issue 12 2007
Nimeshan Geevasinga
Background: Without ventilatory support, premature death from respiratory insufficiency is virtually universal in infants with spinal muscular atrophy type 1 (SMA1). With mechanical ventilation, however, long-term survival has been reported from numerous international centres. We aimed to characterize physician attitudes to the various forms of ventilatory support for children with SMA1. Methods: We surveyed neurologists, respiratory physicians, clinical geneticists and intensivists from all major paediatric hospitals in Australia and New Zealand regarding their views on ventilatory management of SMA1. Results: Ninety-two of the 157 (59%) physicians surveyed replied. Respondents included 16 clinical geneticists, 19 intensive care physicians, 28 neurologists and 29 respiratory physicians. Almost half (47%) opposed invasive ventilation of children with SMA1 and respiratory failure precipitated by intercurrent illness. The majority (76%) opposed invasive ventilatory support for chronic respiratory failure in SMA1. In contrast, non-invasive ventilation was felt by 85% to be appropriate for acute respiratory deteriorations, with 49% supporting long-term non-invasive ventilatory support. Most physicians felt that decisions regarding ventilation should be made jointly by parents and doctors, and that hospital Clinical Ethics Committees should be involved in the event of discordant opinion regarding further management. A majority felt that a defined hospital policy would be valuable in guiding management of SMA1. Conclusions: Respiratory support in SMA1 is an important issue with significant ethical, financial and resource management implications. Most physicians in Australian and New Zealand oppose invasive ventilatory support for chronic respiratory failure in SMA1. Non-invasive ventilation is an accepted intervention for acute respiratory decompensation and may have a role in the long-term management of SMA1. Clinical Ethics Committees and institutional policies have a place in guiding physicians and parents in the management of children with SMA1. [source]

Flow-dependent resistance of nasal masks used for non-invasive positive pressure ventilation

RESPIROLOGY, Issue 4 2006
Wolfram WINDISCH
Objective and background: Endotracheal tube resistance is known to be flow-dependent and this understanding has improved the application of invasive ventilation. However, similar physiological studies on the interface between patients and non-invasive positive pressure ventilation (NPPV) have not been performed. Therefore, this study was aimed at investigating the resistance of nasal masks used for NPPV. Methodology: The flow-dependent pressure drop of the small (S), medium-small (MS) and medium (M) Contour Nasal Mask (Respironics Inc., Murrysville, PA, USA) was measured with and without a connecting tube (length 18 cm, internal diameter 1.5 cm) in a laboratory study. The resistance was calculated by Rohrer's equation using the standard least-squares-fit technique. The present study explicitly differentiated between the resistance of the nasal mask alone when measured against atmosphere and the additional resistance caused by the nasal mask when airtightly fitted to a model head (interaction with the face). Results: Higher flow rates resulted in a non-linearly increasing pressure drop across the interface. This flow-dependent resistance of the S/MS/M mask was comparably low when not interacting with the face, but increased when interacting with the face. This flow-dependent resistance of the mask was several-fold higher when adding the connection tube and tended to be higher during expiration. Conclusion: There is a non-linear flow-dependent pressure drop across the nasal mask which is low and independent of its size, but increases when interacting with the face. The connecting tube is the major determinant of the resistance originating from facial appliances used for NPPV. [source]

An assessment of the validity of SOFA score based triage in H1N1 critically ill patients during an influenza pandemic

ANAESTHESIA, Issue 12 2009
Z. Khan
Summary Sequential Organ Failure Assessment (SOFA) score based triage of influenza A H1N1 critically ill patients has been proposed for surge capacity management as a guide for clinical decision making. We conducted a retrospective records review and SOFA scoring of critically ill patients with influenza A H1N1 in a mixed medical-surgical intensive care unit in an urban hospital. Eight critically ill patients with influenza A H1N1 were admitted to the intensive care unit. Their mean (range) age was 39 (26,52) years with a length of stay of 11 (3,17) days. All patients met SOFA score based triage admission criteria with a modal SOFA score of five. Five patients required invasive ventilation for a mean (range) of 5 (4,11) days. Five patients would have been considered for withdrawal of treatment using SOFA scoring guidelines at 48 h. All patients survived. We conclude that SOFA score based triage could lead to withdrawal of life support in critically ill patients who could survive with an acceptably low length of stay in the intensive care unit. [source]