How To Manage Non-Cardiac Surgery in CHD Patients?
Patients with acyanotic CHD require meticulous intraoperative and postoperative care for non-cardiac procedures. The problems that need to closely follow during surgery include: hemodynamic status, ventilation, blood coagulation, renal function and anesthesia care. In the high risk patient, referral to a tertiary center is appropriate even for a minor operative intervention. Patients will be followed by an adult congenital cardiologist and cared for by a cardiovascular anesthesiologist.
Perioperative management of patients with cyanotic CHD and those with pulmonary vascular disease is very complex and carries a high risk. Special precaution to prevent dehydration and hypovolemia is critical. Large fluctuation can lead to an increase of R-to-L shunting with a decrease of pulmonary blood flow. Hypercapnia and hyposxia can stipulate an increase of pulmonary vascular resistance. Close monitoring of intravascular blood volume and cautious use of vasodialators, including regional anesthesia are mandatory.
An enlarged pulmonary artery secondary L-to R shunt or pulmonary hypertension can result in chronic compression of a bronchus resulting in hypertension can result in recurrent or chronic atelectasis, pneumonia or emphysema. The patients can have diaphragmatic palsy due to phrenic nerve injury from previous surgery. They can have scoliosis that is not severe enough to impair pulmonary function but restrictive airway obstruction is well recognized.
If the hematocrit is more than 65% patients should have prophylactic phlebotomy in order to ameliorate hemostasis and minimize post-operativ bleeding. The bleeding time is prolonged while the partial thromoplastin time is normal. In addition, a special method of partial thromboplastin time monitoring is required.
In the presence of intracardiac shunt, special devices should be used to prevent cerebral embolization or brain abscess. Filters should be placed in intravenous lines with scrupulous attention in maintain all venous lines free of air or bubbles to reduce the risk of paradoxical embolization.