Ligation of the patent ductus arteriosus in newborn respiratory failure.

Patent ductus arteriosus (PDA) is commonly associated with respiratory disease in newborn infants and may require ligation. Surgical ligation of the PDA can be done in small infants with low operative risk and minimal complications. The outcome of patients after ligation depends primarily on the severity of the underlying pulmonary disease. One hundred fifty-one patients have undergone ligation in an eight-year period at this center. A simplified technique performed in the neonatal intensive care unit with the use of local anesthesia and conventional ventilator management is described.

Growth changes in the thoracic aorta of the piglet following patch angioplasty.

Patch repair of the thoracic aorta using prosthetic graft material in neonates and infants has been advocated, but long-term results have not confirmed that the residual aorta grows. In this study five piglets had portions of aortic tissue excised, ranging from 38% to 72% of the aortic wall. Each pig underwent patch angioplasty repair of the thoracic aorta with prosthetic graft material. Piglets achieved full growth at approximately six months. Aortic catheterization and contrast angiography were done in each animal before it was killed. Growth and histologic study of the aorta was documented at postmortem examination. There were no blood pressure gradients at rest or with isoproterenol hydrochloride (Isuprel)-epinephrine challenge in four of the five piglets. In one animal that underwent a 72% resection of the aortic circumference, a 20-mm gradient was present at rest. It was concluded that the thoracic aorta in piglets will grow adequately to allow patch grafting of up to 70% of the aortic circumference.

Comparative effects of morphine, meperidine and pentazocine on cardiocirculatory dynamics in patients with acute myocardial infarction.

The cardiocirculatory effects of the commonly used parenteral analgesics, morphine sulfate 15 mg, meperidine hydrochloride 100 mg and pentazocine 60 mg, each administered intravenously, were compared in 12 patients with acute myocardial infarction during cardiac catheterization and by echocardiogram. No untoward hemodynamic effects occurred following the administration of morphine or meperidine. In contrast, pentazocine produced significant (p less than 0.01 to less than 0.05) increases in systemic and pulmonary arterial pressures, left ventricular filling pressure, systemic vascular resistance, and systolic and diastolic dimensions; and decreases in left ventricular ejection fraction and mean velocity of circumferential fiber shortening. These deleterious actions of pentazocine appeared due to peripheral vasoconstriction and negative inotropic properties. Further, pentazocine-induced increases in left ventricular preload and afterload increased myocardial oxygen demands. Since this study demonstrates that pentazocine is hazardous in myocardial infarction, morphine and meperidine are the preferred analgesics in this condition.