Epidural sufentanil during paediatric cardiac surgery: effects on metabolic response and postoperative outcome.

The metabolic and neuroendocrine effects of caudal epidural analgesia were studied during paediatric cardiac surgery. Combined epidural and general anaesthesia (EPI group; n=12) was compared with deep opioid anaesthesia (DOA group; n=12). During anaesthesia and surgery, haemodynamic stability was similar in the two groups. There was no significant difference between groups concerning the metabolic response to surgery but circulating catecholamines were significantly lower in the EPI group during and after surgery. Perioperative release of IL-6 was higher in the EPI group possibly reflecting a longer aortic clamp time. Incidence of postoperative life-threatening dysrhythmias was very low in the two groups. No significant reduction of postoperative mechanical ventilation, intensive care unit or hospital stays was reported with epidural analgesia. The incidence of postoperative infections was higher than expected in the two groups because of the poor properative clinical status of most of the children included in the study.

Hemodynamic effects of synchronized high-frequency jet ventilation compared with low-frequency intermittent positive-pressure ventilation after myocardial revascularization.

BACKGROUND: The purpose of this prospective study was to examine the effect on cardiac performance of selective increases in airway pressure at specific points of the cardiac cycle using synchronized high-frequency jet ventilation (sync-HFJV) delivered concomitantly with each single heart beat compared with controlled mechanical ventilation in 20 hemodynamically stable, deeply sedated patients immediately after coronary artery bypass graft. METHODS: Five 30-min sequential ventilation periods were used interspersing controlled mechanical ventilation with sync-HFJV twice to control for time and sequencing effects. Sync-HFJV was applied using a driving pressure, which generated a tidal volume resulting in gas exchanges close to those obtained on controlled mechanical ventilation and associated with the maximal mixed venous oxygen saturation. Hemodynamic variables including cardiac output, mixed venous oxygen saturation and vascular pressures were recorded at the end of each ventilation period. RESULTS: The authors found that in 20 patients, hemodynamic changes induced by controlled mechanical ventilation and by sync-HFJV were similar. Cardiac index did not change (mean +/- SD for controlled mechanical ventilation: 2.6 +/- 0.7 l x min(-1) x m(-2); for sync-HFJV: 2.7 +/- 0.7 l x min(-1) x m(-2); P value not significant). This observation persisted after stratification according to baseline left-ventricular contractility, as estimated by ejection fraction. CONCLUSIONS: The authors conclude that after coronary artery bypass graft, if gas-exchange values are maintained within normal range, sync-HFJV does not result in more favorable hemodynamic support than controlled mechanical ventilation. These findings contrast with the beneficial effects of sync-HFJV, resulting in marked hypocapnia, on cardiac performance observed in patients with terminal left-ventricular failure.

Aortic valve repair by cusp extension with the use of fresh autologous pericardium in children with rheumatic aortic insufficiency.

OBJECTIVES: Our goal was to evaluate the midterm results of aortic valve repair by a more sophisticated tailoring of cusp extension-taking into account the dimensions of the native aortic cusps-with the use of fresh autologous pericardium. PATIENTS AND METHODS: Forty-one children who had severe rheumatic aortic insufficiency (mean age 11.5 +/- 2.7 years) underwent aortic valve repair by means of this cusp extension technique over a 5-year period. Twenty-four of them underwent concomitant mitral valve repair for associated rheumatic mitral valve disease. All children were then followed up by transthoracic echocardiography before discharge, at 3 and 6 months after the operation, and at yearly intervals thereafter. RESULTS: Follow-up was complete in all patients and ranged from 3 months to 5 years (median 3 years). No operative and no early postoperative deaths occurred. Only 1 patient died, 9 months after the operation, of septicemia and multiple organ failure. Actuarial survival was 97% at 1 year and has remained unchanged at 3 years. On discharge, the degree of aortic insufficiency was grade 0 for 27 children and grade I for 14. Exacerbation of aortic insufficiency from grade I to grade II was observed in only 1 patient, and none of the children required reoperation for aortic insufficiency during the follow-up period. Mean peak systolic aortic valve gradients at discharge were lower than preoperative values (P =.04), and no significant increase in the peak systolic transvalvular gradient was detected thereafter during the follow-up period. Mean left ventricular dimensions were significantly reduced at discharge when compared with preoperative values (P <.0001). CONCLUSIONS: Functional results of aortic valve repair with cusp extension using fresh pericardium have been satisfactory at medium term, particularly in children with a small aortic anulus at the time of initial repair, because the expansion potential of fresh autologous pericardium is equivalent to that of the growing sinotubular junction and aortic anulus diameters.

Can gastric intramucosal pH (pHi) predict outcome of paediatric cardiac surgery?

In forty-two children undergoing cardiac surgery using hypothermic cardiopulmonary bypass (CPB), a gastric tonometer was used intraoperatively to estimate pHi, reflection of splanchnic perfusion. PHi monitoring was used to predict early postoperative complications. Intramucosal acidosis appeared after removal of the aortic clamp and remained after weaning of CPB. Fifteen children (group C) developed early postoperative life-threatening complications. Twenty-seven children (group NC) had no major complications. Retrospective data analysis showed a decrease of pHi during hypothermic CPB in the two groups but at completion of surgery, pHi was significantly lower in the group C (7.13 +/- 0.04 vs 7.31 +/- 0.001, P < 0.001). Bypass and aortic clamp times were also longer in group C and intraoperative core temperature lower. Continuous automated tonometer gas analysis appeared more accurate for the monitoring of acute haemodynamic and respiratory changes and should probably improve the predictive value of tonometry in the future. Tonometry is highly sensitive and represents an interesting and minimally invasive monitoring for critically ill children.

[Coronary surgery without extracorporeal circulation. Indications, methods and results. Apropos of 224 cases]. / Chirurgie coronaire sans circulation extracorporelle. Indications, technique et résultats. A propos de 224 patients.

Coronary revascularization without cardiopulmonary bypass is evolving as an important technique. From January 1988 to September 1997, 224 patients underwent consecutively coronary artery bypass grafting without cardiopulmonary bypass in our institution. Indications for this type of revascularization were essentially: patients with a single coronary lesion and patients which presented an increased risk for extra-corporeal circulation. Follow-up was complete. The majority of patients were men (176) and the median age was 62 years. Most patients were in CCS III and IV (79%). Unstable angina was found in 19%, 4% had a recent trans mural infarction (< or = 48 hr), and 36% had an older infarct (> 48 hr). 8% were operated in emergency, 29% presented a restenosis following angioplasty, with 4% having a complication from angioplasty, and 0.8% were operated in cardiogenic shock. Redo surgery was seen in 4% of patients. 12% of patients had an ejection fraction less than 30%, 47% an ejection fraction between 30 et 49%, and 40% patients an ejection fraction greater than 50%. Mean Parsonnet score was 10. 185 patients (82.5%) underwent single bypass, and 39 patients (17%) multiple bypasses. Ten patients (4.4%) underwent hybrid revascularization with primarily surgical grafting followed by angioplasty. Postoperative outcome included: myocardial infarction in 16 patients (7.1%), 8 patients (3.5%) were reoperated for tamponade or bleeding, 2 patients (0.8%) developed a mediastinitis, and 1 patient (0.4%) had a neurological event. Hospital mortality was 4% (9 patients). Univariate and multivariate analysis identified two risks factors: age greater than 70 (OR 4.2, CI 1-18.4), and an ejection fraction less than 30% (OR 5, CI 1.2-21.6). Survival was 99.1% at 1 year, 94% at 3 years and 83.2% at 7 years. Post operative angina occurred in 33 patients, linked to a coronary anastomosis dysfunction in 9 patients (4.1%). A significant reduction of cost was found, compared to patients operated with extra-corporeal circulation. We conclude that coronary revascularization without cardiopulmonary bypass can provide satisfactory results, for patients with single coronary lesion, or for patients with an increased risk and multiple coronary lesions.

Successful weaning from cardiopulmonary bypass after cardiac surgery using inhaled nitric oxide.

Two cases of very difficult weaning from cardiopulmonary bypass after cardiac surgery in children with pulmonary hypertension and ventricular dysfunction are reported. Children fail to respond to conventional therapy combining nitrovasodilators and inotropic support and react successfully to combined inhaled nitric oxide (NO) and epinephrine or left atrial infused norepinephrine. Postoperative NO inhalation must be prolonged and no toxicity appears. Pulmonary endothelial function recovers only after several days.

Malignant hyperthermia and severe hypoglycemia after reexposure to halothane.

A four year child presented with an episode of malignant hyperthermia induced by reexposure to halothane. The episode was associated with early onset of a severe hypoglycemia and liver enzymatic perturbances. Etiology of these perturbances is hard to state precisely in this clinical context, but a hepatic toxicity of halothane and/or by dantrolene is considered.

Total intravenous anesthesia in South-African genetic porphyria (variegate porphyria).

The authors report the case of a female patient with South-African genetic porphyria who had to undergo hepatic tumorectomy under general anesthesia. The choice for propofol as the induction and maintenance agent using a balanced anesthetic technique led to a significant rise in urinary excretion of porphyrins without associated clinical manifestations. A short review of the literature on physiopathology of porphyrias and medicinal agents, susceptible to induce acute porphyric crisis follows. The authors conclude that the innocuity of propofol as induction and maintaining agent in the porphyric patient cannot be yet established without further studies.