Sunday, January 1, 2012
myotonic dystrophy
ECT
vacuum insulated evaporator
Oxygen is manufactured by the fractional distillation of air. Air is compressed to 5 atmospheres and cooled to -181oC using reverse heat exchangers. A two-stage distillation process yields 99.5% O2 (and 0.4% argon). It is stored at 137 bar in silver cylinders with green shoulders in the United States. Storage of Oxygen: The VIEHospitals store large quantities of oxygen as a liquid in a vacuum insulated evaporator (VIE). Compensatory adjustments made by the VIE systemIf there is a period of low oxygen use or hot weather this will result in the temperature of the liquid oxygen increasing.. This leads to increased pressure in the VIE and at 1500KPa the blowoff valve opens allowing vaporisation into the environment, (the latent heat of vaporisation cools the liquid oxygen). If there is a period of high oxygen use by the hospital or very cold weather, there will be reflected by a decreased temperature of liquid oxygen and thus a decreased pressure in the VIE system. At 1000KPa the Pressure Raising Valve (PRV) opens, and allows liquid oxygen to shunt through a Pressure Raising Vapouriser (PRV). This allows environmental heat to enter the system. This mechanism ensures that the pressure and temperature of the VIE rises back to normal. All outgoing gases pass through a heat exchanger to warm them. |
Tuesday, December 13, 2011
medical vivas
STEMI
unilateral white out: differentials- previous pneumonectomy, hemothorax, collapse
bilateral pneumothorax
Wednesday, December 7, 2011
anaesthesia for renal transplant
1) comorbidities,
2) medications: immunosuppressants, anti-hypertensives
3) ESRF and underlying cause of it
-should have dialysis in 24 hours before op
Anaesthesia technique
GA: IPPV. (RA:caution in uraemic patients, residual heparin, concurrent liver disease)
CVP: for fluid monitoring. Aim 12-14. MAP: high normal
IA: not mandatory
TEE
Esophageal spasm.
Esophageal stricture.
Esophageal laceration.
Esophageal perforation.
Esophageal diverticula (e.g. Zenker's diverticulum).
Relative contraindications:
Large diaphragmatic hernia may significantly hinder TEE imaging because of lack of transducer mucosal approximation.
Atlantoaxial disease and severe generalized cervical arthritis: TEE should never be performed if there is any question about stability of cervical spine.
Patients who received extensive radiation to the mediastinum: this can cause significant difficulty in probe manipulation within the esophagus and is a relative contraindication if the anatomy of the esophagus is not known.
Upper gastrointestinal bleeding, significant dysphagia and odynophagia are also relative contraindications
Indication:
cardiac output
valve
congenital heart disease
evaluation of LA and LA appendage before cardioversion