University:
Western Sydney University
Course:
MEDI 2003 | Clinical Sciences 2
Academic year:

2024
Views:

109

Pages:

3
Author:

Mariam A. A.

Sources of Infection • • • • • • Oral temperature: - External carotid artery. - Measurement is affected by mouth breathing, hot or cold drinks and smoking. Tympanic membrane: - Tributary of the artery supplying the hypothalamus. - Detects radiant energy coming from the tympanic membrane. Axillary temperature: - Approximates core temperature in neonates. - Not accurate in adults or children. Forehead - Temporal artery. - Easy, especially in children while a sleep. Rectal temperature - Synonyms with core temperature. - Used in neonates, ICU. - May be raised due to faecal bacteria. Right atrium - Inaccessible unless the patient is catharised in the great veins. Intravenous Catheters • • • • • Peripheral - IV cannulas Central - Hickman’s catheters: central line that is placed on the right side of the chest wall. - In subclavian artery, JV, haemodialysis, percutaneously inserted catheters. Causative: - Coagulase negative: S. Epidermis and other staphylococcus organisms. - Coagulase positive: S. aureus. - Yeast esp. candida spp. Diagnosis: - Unreliable: fever, chills, local inflammation -> insensitive. - Heparin and TPN lines are high risk. - Absence of other foci suggestive. - Need two sets. - Sensitivity increases with volume of blood samples. - Take peripherally not via the lines -> less likely to be contaminated. - Maki method -> rolling each catheter tip to an agar plate. (semi-qualitative). Definitions (HICPAC): - Catheters: bugs on the tips. - Phlebitis: inflammation at insertion sites. - Exist site infection -> exudate growing. - Tunnel infection -> in tunnelled line. - Pocket infection -> in implant. • • • • Complications: - Infective endocarditis. - Osteomyelitis. - Septic arthritis. - Metastatic abscesses. Empirical antibiotics: - Flucloxacillin and gentamicin. - Vancomycin and gentamicin. - Ceftriaxone won’t cover most bacteria. Specific antibiotics: - Consider complicated vs. uncomplicated. - What organism is present. - Susceptibility profiles. Prevention: - Pull IV line when not needed. - Education and surveillance. Blood Cultures • • Two bottles -> one for aerobics and one for aerobics, Colorimeter detection: - Detect CO2 made by bacteria. - The volume scale -> aim for 10mL. - Positive -> yellow. - Negative -> green. - Machine reads the bottom of the bottle -> detects when there is a colour change. • • • • • • • As sensitivity increases, specificity decreases. Contamination risks -> contaminated organism may look same as the causative pathogen. Positive increases linearly in adults until 30mL to 40mL drawn. Need to set from two venesections: - Optimal blood volume. - Makes sorting contaminants vs real pathogens easy. Positivity increases with sets: - 1 set -> 75%. - 2 sets -> 90%. - 3 sets ->99%. - 4 sets -> 100%. Ignore peer pressure to: - Take all the bloods from the canula. - Take on set only. In children take less blood as they have a less blood volume.