Skip to main content

Organ donation..Organ support after brain death




Physiological derangements after brain death are an extension of those which occur with severe brain injury.

  • Initial dysautonomia and catecholamine release -> labile HT and tachycardias
  • Subsequent hypotension due to neurogenic decrease in SVR and / or myocardial dysfunction
  • Neurogenic diabetes insipidus
  • Non-cardiogenic pulmonary oedema
  • Hyperglycaemia
  • Coagulopathy
  • Poikilothermia
Management includes

a) Ventilatory control:

Optimum ventilation strategy uncertain. Recommended aims:
·PaO2 > 100mmHg
·PaO2:FiO2 > 250
·PaCO2 35 - 45mmHg
·Avoid pulmonary congestion
·Methylprednisone 15mg/kg may improve oxygenation
·Regular routine turning and tracheal toilet

b) Circulatory control:

·Volume replacement - crystalloids tend to pulmonary oedema, starch compounds impair graft function
·Inotrope support . Adrenalin promotes hyperglycaemia, but may reduce acute graft rejection.Dobutamine ineffective.
·Short acting ß-Blocker may be used for significant tachycardias. Clonidine will not work once brain dead.
·Vasopressin 1iU IV bolus + 0.01 - 0.04iU/kg/hour IVI controls diabetes insipidus (V2 receptor) and may lower inotrope requirements (V1 receptor).
Corticosteroid may smooth haemodynamics

c) Metabolic control

·Diabetes insipidus is managed with intermittent dDAVP 2 - 4 ucg q2-6hr IV (acts at V2 receptor only) or a
Vasopressin infusion at 0.01 - 0.04iU/kg/hour (acts at V1 and V2 receptors) to maintain U/O between
0.5 - 3 ml/kg/hr.
·Hyperglycaemia is managed with insulin IVI
·Electrolytes are kept within normal ranges by usual methods.
·Temperature kept 35 - 37C. Prevents left shift of Hb-O2 dissociation curve.
·Sick euthyroid pattern may occur but replacement does not improve haemodynamics.
·Corticosteroid (methylprednisone 15mg/kg) may smooth haemodynamics, reduce transplant immunogenicity and improve transplanted lung function.
·Hormonal optimisation (methylprednisone + vasopressin + T3 or T4) may improve donor transplant rates,
esp cardiac transplant. Recommended in UK based on retrospective analysis in 2003.

d) Renal support

Maintaining haemodynamic and metabolic control, improves donor kidney outcome and reduces graft rejection and recipient mortality.

e) Hepatic support

·Maintaining nutritional support lessens hepatic glycogen depletion. Dextrose and insulin or enteral nutrition.
·Maintaining serum Na < 155mmol/L reduces graft failure.
·Haemodynamic support minimises hepatic ischaemia Determining cardiac

Labels:

Comments

Post a Comment

Popular posts from this blog

Things to Avoid in Anesthesia for Pregnant with Pulmonary hypertension

Anesthesia for Pregnant woman with Pulmonary Hypertension is a real challenge for anesthesiologist. It is very crucial to remember the pathophysiology of pulmonary hypertension in pregnant women and to avoid some practices that will worsen the cardiac status. 1-Avoid single shot spinal anesthesia. Some authorities consider pulmonary hypertension as absolute contraindication for single shot spinal anesthesia specially in patients with NYHA III ,IV. Spinal anesthesia causes major hemodynamic instability(decrease SVR, decrease VR, decrease in CO) The preferred neuroaxial techniques are (epidural anesthesia and CSE with minimal spinal dose) 2-Avoid PAC. Pulmonary Artery catheters insertion may lead to pulmonary artery rupture or thrombosis. TEE is better cardiac monitor/Arteial line is mandatory. 3-Avoid Nitrous oxide in gas mixture.N2O increase the PVR 4-If MV to be started, avoid High TV and PEEP 5-Avoid Oxytocin Boluses, or rapid administration of Pitocin. Oxytocin causes ...
Post a Comment
Read more

power injectable peripherally inserted central catheters

Clinical experience with power injectable peripherally inserted central catheters in intensive care patients     Introduction In intensive care units (ICU), peripherally inserted central catheters (PICC) may be an alternative option to standard central venous catheters, particularly in patients with coagulation disorders or at high risk for infection. Some limits of PICCs (such as low flow rates) may be overcome by the use of power-injectable catheters . Method We have retrospectively reviewed all the power injectable PICCs inserted in adult and pediatric patients in the ICU during a 12-month period, focusing on the rate of complications at insertion and during maintenance. Results We have collected 89 power injectable PICCs (in adults and in children), both multiple and single lumen. All insertions were successful. There were no major complications at insertion and no episodes of catheter-related blood stream infection. Non-infective complications ...
1 comment
Read more

Lumbar and thoracic epidural in Pediatrics-Technical aspect

The midline approach is most commonly used. The ligamentum   flavum is considerably thinner and less dense in infants than in older children and adults. This makes recognition of engagement in the ligament more difficult and requires both extra care and slower, more deliberate passage of the needle to avoid subarachnoid puncture. The angle of approach to the epidural space is slightly more perpendicular to the plane of the back than in older children and adults, owing to the orientation of the spinous   processes in infants and small children. The loss of resistance technique should be used, but only with saline, not air. There are several reports of venous air embolism in infants and children when air was used to test for loss of resistance Use a short (5 cm) 18-gauge Tuohy needle and a 20- or 21-gauge catheter in infants and children. Epidural kits specifically for infants and children are available Maximum of 0.4 mg/kg/hr of bupivacaine after the initial block is estab...
Post a Comment
Read more