Non Cardiac Surgical Applications of Cardiopulmonary Bypass
CURRENT APPLICATIONS OF CPB FOR NON CARDIAC SURGERY
- Bypass is used to induce profound hypothermia.
- Patients with significant pulmonary disease requiring surgery that demands a bloodless field constitute second largest group.
- Operations on IVC require bypass procedure to return blood to the heart-venoatrial/venovenal diseases.
- Variety of unusual diseases.
1.HYPOTHERMIA
☛ profound hypothermia & circulatory arrest for craniotomies
☛ 15* to 17* c-cooling point for cerebral protection
☛ 3.9ml/100gm/min -37*c
☛ 1.8ml/100gm/min -27*c
☛ 0.5ml/100gm/min -18*C
☛ Decreased CMRO2 ➙ inhibition of ontegrated neuronal function as reflected in isoelectric ECG
☛ External cranial cooling-surface cooling+blood cooling—best protection
15-60 min safe ischemic time
MANAGEMENT OF CIRCULATORY ARREST
☛ hypothermia provides cerebral protection
☛ muscle relaxant & antibiotics should be considered
☛ pH stat management- cerebral blood flow-uniforma cooling
☛ barbiturates
☛ use of corticosteroids
NEUROSURGICAL PROCEDURES
☛ Subcortical tumour like cyst first procedure
☛ intracranial aneurysm
☛ peripheral bypass avoided thoracotomy
*Refinements in neuroanaesthesia
☛ include microscope,drainage of CSF,controlled hypotension & sophisticated intracranial pathology surgery much safer than use of CPB
☛ risk of ventricular distension
☛ ?CSF drainage in heparinized patients
☛ neurologic dysfunction
☛ intraop assessment is not possible because ofanaesthesia,hypothermia,CPB\
COMPLICATIONS RELATED TO CPB
☛ BLEEDING
☛ NEUROLOGIC DYSFUNCTION
☛ LESS ATHEROSCLEROTIC COMPLICATIONS
USE IN UROLOGIC SURGERIES
☛ Renal malignancies-renal cell Carcinoma ,hypernephroma,tumours invading IVC with right atrial extension
☛ Femoral iv cannula &IJV cannula venovenous bypass
Management of CPB
☛ During positioning tumour dislodges to atria causes hypotension so lt lateral decubutus given
☛ TEE is valuable
☛ Profound hypothermia to remove rt atrial tumour 10-45 min
☛ Double filter or a swollen pea size filter may be placed in bypass arterial line
Complications
☛ Bleeding from retroperitoneal bed
FOR THORACIC PROCEDURES-
☛ Tracheal tumour resection
☛ Tracheal stenosis
☛ Pulmonary embolectomy
☛ Pulmonary transplantation
ANTERIOR MEDIASTINAL MASS
☛ During general anaesthesia induction hypoxia.
☛ Even after intubation-IPPV
☛ Compression of airway by mass
☛ Compression distal to trachea
ISOLATED LEFT HEART BYPASS
☛ Tandem heart PVAD (percutaneous ventricular assist device)
VENOVENOUS BYPASS
☛ Oxygenetor is notused incirculation
☛ Arterial system is not perfused therefore pressure in system is lower
☛ Circuit sealing as only conduit for blood from one or more regions of body to rt heart
Use
- T/t -resp failure
- Management of liver transplantation
- < 5%-venovenous bypass
- During anhepatic phase-1.improved hemodynamic stability
- decreased intraoperative blood loss
- venous decompression
- Caval resection
- Accidental hypothermia