I POSTOPERATIVE CARE Intensive Care Units Rationale for Controlled Oxygen Therapy Excess oxygen can be harmful. Like many drugs, oxygen can be associated with toxicity and excess of oxygen can be harmful to lungs (pulmonary endothelium). The use of inspired oxygen greater than 60% should be avoided. Decreasing the amount of supplemented oxygen at the earliest possible time should be routine practice. Venturi Principals of Operation The Venturi works in a similar fashion to a carburetter in a car engine. Oxygen is delivered into the Venturi barrel. As the oxygen passes through the barrel it draws in a calculated amount of air which mixes with the oxygen. The resulting oxygen/air mixture is then delivered into the BUSTER ICU Cage. The amount of air drawn in by each Venturi is determined by the size of the holes in the Venturi. Each Venturi delivers a constant % oxygen/air enrichment independent of oxygen flow rate. Choice of Venturi Different conditions require different levels of oxygen enrichment. For instance, an animal with fractured ribs only needs 24-28% oxygen enrichment while an animal with congestive cardiac failure requires 60% oxygen enrichment. Each Venturi corresponds to different % enrichment. See below. Diagram 1 Conditions where the alveolar oxygen exchange mechanism is unaffected, but there is mechanical or physiological compromise of ventilation Examples: Pre and post anaesthetic oxygenation of rabbits Fractured ribs Diaphragmatic hernia Conditions where the alveolar oxygen exchange mechanism is compromised Conditions where the alveolar oxygen exchange mechanism is severely compromised Examples: Longstanding obstructive airway disease (Chronic bronchitis) Mild lung contusion Examples: Severe lung contusion Pneumonia Lung congestion Congestive cardiac failure Choice of Venturi 24% 28% 35% 40% 60% 100% 24% 19643 Use of Oxygen leaflet INT 2016.indd 2 28% 35% 40% 60% www.kruuse.com 17/03/17 12:46
Download PDF file