The low resistance strategy for the perioperative management of the Norwood procedure.
BACKGROUND
Postoperative course of the Norwood procedure is fragile because of an unstable pulmonary to systemic blood flow ratio caused by fluctuation of systemic and pulmonary vascular resistance.


METHODS
Twenty-seven patients with hypoplastic left heart syndrome who underwent the Norwood procedure from June 1998 to February 2002 were managed with the following low-resistance strategy. Intraoperative high-flow and low-resistance cardiopulmonary bypass was achieved with total avoidance of circulatory arrest and a large dose of chlorpromazine. In weaning from the bypass, pulmonary vascular resistance was maximally decreased by inspired oxygen fraction (100%), inhaled nitric oxide (20 ppm), and nitroglycerin (2 to 4 microg/kg/min). Then pulmonary blood flow was determined by adjusting the systemic to pulmonary shunt. Postoperatively, with continuous infusion of chlorpromazine and nitroglycerin as a systemic and pulmonary vasodilator, the inspired oxygen fraction and inhaled nitric oxide were tapered as the arterial oxygen saturation improved.


RESULTS
In most patients, inhaled nitrous oxide and inspired oxygen fraction were weaned within 3 days. The postoperative course was stable with minimum changes in circulatory and respiratory status for the survivors. Patients were extubated on a median of 6 postoperative days. Early mortality was 11.1% (3 of 27), and none of the patients died of hemodynamic deterioration.


CONCLUSIONS
The low resistance strategy is a simple and useful method for perioperative management of the Norwood procedure, minimizing fluctuation in both pulmonary and systemic vascular resistance and maintaining stable circulatory and respiratory status.
Nakano
Toshihide
T
Department of Cardiovascular Surgery, Fukuoka Children's Hospital, Japan.
Kado
Hideaki
H
Shiokawa
Yuichi
Y
Fukae
Koji
K
Nishimura
Yosuke
Y
Miyamoto
Kazuyuki
K
Tanoue
Yoshihisa
Y
Tatewaki
Hideki
H
Fusazaki
Naoki
N
D006348:Cardiac Surgical Procedures / Q000379:methods*; D002315:Cardiopulmonary Bypass / Q000379:methods*; D002746:Chlorpromazine / Q000627:therapeutic use; D006801:Humans; D018636:Hypoplastic Left Heart Syndrome / Q000601:surgery*; D007231:Infant, Newborn; D009569:Nitric Oxide / Q000494:pharmacology; D005996:Nitroglycerin / Q000494:pharmacology; D010100:Oxygen / Q000494:pharmacology; D010166:Palliative Care; D019990:Perioperative Care / Q000379:methods*; D011182:Postoperative Care; D011652:Pulmonary Circulation / Q000187:drug effects / Q000502:physiology; D014655:Vascular Resistance / Q000502:physiology*
D009569:Nitric Oxide; D005996:Nitroglycerin; D010100:Oxygen; D002746:Chlorpromazine