Hypercyanotic Spells Research Articles

Extracorporeal life support in cyanotic congenital heart disease before cardiovascular operation

From July 1988 to March 1991, extracorporeal membrane oxygenation (ECMO) was used in 8 infants (newborn to 16 months old) with unoperated cyanotic congenital heart disease and cardiopulmonary collapse, associated with hypercyanotic spells (4 infants), pulmonary hypertensive crises (3) and sepsis (1). Indications for ECMO support were arterial saturations ≤60% accompanied by hypotension and metabolic acidosis unresponsive to mechanical ventilation with 100% oxygen, paralysis and sedation, and pharmacologic support with inotropes or vasodilators, or both. Venoarterial bypass by carotid/jugular cannulation with flow rates of 100 to 840 ml/kg/min (mean 460) stabilized all patients. Duration of ECMO support ranged from 15 to 840 hours and was associated with transient seizures (1 patient) and renal failure (1). Seven patients underwent palliative (3 patients) or corrective (4) surgical procedures while on ECMO or within 48 hours of decannulation, including 1 patient bridged to double-lung transplantation with a long (840 hours) duration of ECMO. There was 1 operative and 2 late (>1 month after decannulation) deaths, for an overall survival rate of 62%. These 5 survivors all have normal growth and development, and patent neck vessels at the site of cannulation. These early results indicate that ECMO can be effective mechanical support in cardiovascular crises unbeatable with maximal conventional medical therapy and can be used as a bridge to successful surgical palliation or repair.

Hypercyanotic spells caused by antegrade catheterization of the pulmonary arteries in tetralogy of Fallot: fact or fiction?

SummaryBetween January 1985 and March 1990, 66 children with the tetralogy of Fallot underwent 85 cardiac catheterization procedures. The mean age at first procedure was 2.5 years (range 0.1–;14.4 years) and the mean weight was 10.4 kg ( range 2.4–36.0 kg). Diagnostic cardiac catheterization was performed in 60 procedures and balloon dilatation in 25. Hypercyanotic spells had occurred prior to 24 (28%) of the procedures (all the patients being on propranolol) and a systemic-to-pulmonary arterial shunt had been constructed before 28 (33%) procedures. Of the procedures, 54 (64%) were performed under local and 31(36%) under general anesthesia. The pulmonary trunk was entered antegradely in 52 procedures, retrogradely through a shunt in 6 and not entered in 27. Balloon dilatation was performed under general anesthesia on 25 occasions. No procedure was abandoned because of a cyanotic spell. Nine (11%) spells occurred during 86 procedures, one of the procedures being postponed because ofa spell occurring after premedication, the procedure and not, therefore, continuing to catheterization. Five spells occurred before the catheter was positioned in the heart, 2 spells occurred during catheterization. Of the spells, eight occurred during procedures in children who had not had previous shunts. Antegrade entry into the pulmonary trunk in the group with shunts was associated with no spells compared with 6/38 (18%) in the group not having undergone surgery (p<0.l). In the group not undergoing surgery, when the pulmonary trunk was not entered, 1 (5%) spell occurred during 19 procedures compared with 6/38 (18%) when the pulmonary trunk was entered (p<0.4). The only clinically important factor which significantly influenced the incidence of spells was the use of general anesthesia, which was associated with 6/31 (19%) spells compared with local anesthesia which was associated with 2/54 (4%) spells (p<0.026).

Esmolol for the treatment of hypercyanotic spells in infants with tetralogy of Fallot

Etude de deux cas cliniques chez des nourrissons avec une tetralogie de Fallot. L'efficacite du traitement par le bloquant β-adrenergique esmolol pour les cardiopathies cyanogenes est demontree

Erythropheresis in children with polycythaemia

Using a hypothetical formula to calculate exchange volumes, erythropheresis was performed on 47 occasions in 20 children with secondary polycythaemia. Following this procedure the mean haematocrit in the patients was reduced from 69.0 to 58.0% (P less than 0.001), and the individual haematocrit to 61% or below. In 39 (83%) of the 47 exchanges the reduction coefficient, i.e., the volume of exchange which effected a unit reduction in the haematocrit, ranged from 1.0 to 3.0 ml/kg bodyweight. The derivation of these coefficients facilitated the formulation of an equation which expresses the volume of blood (V) that needs to be exchanged in a patient in terms of his weight, observed haematocrit (Hct1) desired haematocrit (Hct2) and the reduction coefficient (RC): V = Bodyweight (kg) X (Hct1 - Hct2) X RC. Haematocrit rebound occurred after 83% 50% and 14% of 30-min, 60-min and 90-min exchanges, respectively, indicating that the optimal duration of the procedure should be between 60 and 90 min. Hypercyanotic spells complicated two of the 47 exchanges and one patient suffered a fatal micturition-related cardiovascular collapse shortly after erythropheresis.

Clinical manifestations of dynamic left ventricular outflow tract stenosis in infants with d-transposition of the great arteries with intact ventricular septum

Four infants with d-transposition of the great arteries and intact ventricular septum who manifested early clinical symptoms and deterioration due to dynamic left ventricular outflow stenosis are presented. All four had an anatomically adequate atrial septal defect, made at the initial balloon atrial septostomy, that was later confirmed intraoperatively. Two infants continued to have a low arterial oxygen saturation level because of inadequate interatrial mixing, and one of these had severe persistent cyanosis and was treated with the Mustard operation at age 4 days. The other two infants subsequently presented with hypercyanotic spells at age 3 months. All four infants had features of dynamic left ventricular outflow stenosis on hemodynamic, angiocardiographic and echocardlographic studies. The left ventricular outflow pressure gradient was shown to increase after administration of isoproterenol in one infant, and relief of a cyanotic spell with reduction of left ventricular systolic pressure was achieved in another after intravenous administration of propranolol. The Mustard operation relieved symptoms in all infants. The effect of left ventricular outflow tract stenosis on the mechanisms responsible for interatrial mixing in d-transposition of the great arteries with intact ventricular septum is discussed.

PROPRANOLOL ADMINISTRATION IN INFANCY

Propranolol, (P) the beta blocking agent has been used for treatment of arrhythmia and hypercyanotic spells in infancy. Very little firm data about pharmacologic parameters is available. This series involves P levels in 6 infants. One infant, born to a mother treated with 160 mg P/day had P levels which increased over the first 4 hrs. of life. Two newborns with atrial arrhythmia refractory to Digoxin were begun on small doses of P which were increased until a therapeutic result was obtained (at a dose of 1 mg/kg/24 hr.). Three infants ranging in age from 7-11 mos. (wgt.7-9 kg.) were treated with 2.5 mg/ kg/24 hr. in 4 divided oral doses for hypercyanotic spells. Serial (P) levels were obtained from 45 min. to 6 hrs. following the oral dose and these levels were incorporated into a curve from which the half-life (2.3 hrs.), the elimination, constant (0.005 min.-1) and the volume of distribution (8.13L/kg) of the drug were calculated. The P level decrease with respect to time was a straight line function which yielded a correlation coefficient with those from pharmacokinetic studies in adults. Conclusions: (1) Infants > 7 mos.; > 7 kg. on 2.5 mg/kg/24 hr. metabolize, distribute, and elimiP as adults. (2) In the neonate, these values may not apply and a dose of 1 mg/kg/24 hr. was therapeutic. (3) Given to pregnant women, the drug is stored in the fetal liver and the increased level reflects the inability of the fetus to adequately metabolize the drug.