The incidence of congenital heart disease is about one percent of all live births in the United States. Treatment is being performed at a younger age and these children are showing improved survival. It is not unusual for children with congenital heart disease to present for non-cardiac surgery. Their management depends on their age, type of lesion, extent of corrective procedure, the presence of complications and other congenital anomalies. Each patient needs a detailed pre-operative evaluation to understand the abnormal anatomy and physiology, and related anaesthetic implications. No anaesthetic agent is an absolute contraindication, although drugs beneficial for one lesion may be detrimental for another. Regional anaesthesia has also been safely used in children with congenital heart disease. However the anaesthesiologist must have a detailed understanding of the pathophysiology of the lesion and the pharmacology of drugs being used to be able to provide safe anaesthesia for children with congenital heart disease.

Platelets have a pivotal role in the initial defense against insult to the vasculature and are also recognized of critical importance in the acute care settings of percutaneous coronary intervention and cardiopulmonary bypass. In these environments both platelet count and function may be markedly compromised. Unfortunately, current assays to evaluate the parameters of platelet count and function are of limited utility for bed-side testing. Moreover, it is suggested that there may be significant inter patient variation in response to antiplatelet therapy that may be exacerbated by other agents (e.g. heparin) that are routinely administered during cardiac intervention. Here we describe a practical, rapid and user-friendly whole blood platelet function assay that has been developed for use in bed-side settings. Platelet agonists were formulated with an anticoagulant and lyophilized in blood collection tubes standardised to receive a l mL fresh whole blood sample. In the presence of an agonist, platelets are activated and interact (aggregate). Using traditional cell counting principles, non-aggregated platelets are counted whereas aggregated platelets are not. The percentage (%) of functional platelets in reference to a baseline tube may then be determined. Results are available within four minutes. Platelet aggregation in whole blood demonstrated good correlation with turbidometric aggregometry for both ADP (r=0.91) and collagen (r=0.88). Moreover, in clinical settings where antiplatelet agents were administered, this rapid, bed-side, platelet function assay demonstrated utility in monitoring patient response to these therapies. This novel bed-side assay of platelet function is extremely suitable for the clinical environment with a rapid turn-around time. In addition, it provides a full haematology profile, including platelet count, and should permit enhancement of transfusion and interventional decisions.

The institution of cardiopulmonary bypass generates many pro-inflammatory cytokines and several clinical variables, including temperature, have been shown to influence cytokine release during and after cardiopulmonary bypass. The release of tumour necrosis factor and interleukin-6 are the best predictors of post-cardiopulmonary bypass related morbidity. Their release during normothermic and hypothermic cardiopulmonary bypass and the correlation with clinical parameters of organ injury was studied. This prospective study was carried out in 52 adult patients, scheduled for cardiac surgery, exposed to normothermic and 27 to hypothermic cardiopulmonary bypass. Samples for estimation of tumour necrosis factor and interleukin-6 were collected preoperatively, 1 hour and 24 hours post cardiopulmonary bypass and analysed by ELISA. Haemodynamic parameters and respiratory parameters were noted and lung injury scores calculated. Interleukin-6 levels were raised in both the groups at 1 hour and 24 hours post cardiopulmonary bypass and the response was higher in the normothermic group. Tumour necrosis factor response was, however, similar in both the groups, with a rise at 1 hour returning back to baseline by 24 hours post cardiopulmonary bypass. The normothermic group had a better respiratory index in the postoperative period, early extubation was possible, had better clinical haemodynamics, a shorter cardiopulmonary bypass time and had reduced requirement of defibrillation after the release of aortic cross clamp. We conclude that the release of interleukin-6 was thermo-dependant but did not correlate with the clinical signs of organ injury. Tumour necrosis factor levels were significantly raised after the cardiopulmonary bypass but the rise was not thermo-dependant.

Thirty patients undergoing closed mitral valvotomy were prospectively randomised to receive either thoracic or lumbar epidural catheter. General anaesthesia consisted of morphine sulphate 0.15 mg/kg (single dose given before skin incision), thiopentone sodium 4-6 mg/kg, vecuronium and halothane titrated to stable haemodynamics. In the immediate postoperative period, pain was assessed by VAS (visual analogue scale) and VRS (verbal ranking score) and an epidural fentanyl bolus of 1.5 microg/kg was given followed by an infusion of 0.4 microg/kg/hr. Pain was assessed after 30 min and if pain relief was still inadequate, another fentanyl bolus of 1 microg/kg was administered, followed by an increase in infusion rate to 0.6 microg/kg/hr. If two consecutive pain scores were satisfactory (VAS <4, VRS <1) maintenance dose of fentanyl was decreased by 0.2 microg/kg/hr. Thoracic group received significantly less total dose of fentanyl in 24 hrs period (446.7 +/- 101.70microg) compared with the lumbar group (705.33 +/- 181.03microg) (p<0.01). The mean infusion rate was also significantly less in the thoracic group as compared with the lumbar group (0.44 +/- 0.08microg/kg/hr vs 0.61 +/- 11microg/kg/hr, p<0.001). The side effects were comparable between both the groups and none of the patients had significant respiratory depression. The data suggest that thoracic epidural fentanyl infusion is superior to lumbar infusion for post thoracotomy pain relief because of smaller dose requirement.

Myocardial revascularisation on a beating heart with or without cardiopulmonary bypass has significantly reduced the incidence of cardioplegic myocardial injury. With this advantage in view, noncoronary open heart surgery was performed on a beating heart under cardiopulmonary bypass. We discuss the anaesthetic management of such cases. Thirty-three patients aged 14-56 years underwent open heart surgery on a perfused beating heart. Eleven of them underwent open mitral valvotomy, eighteen underwent mitral valve replacement, repair of atrial septal defect was performed in 3 patients and one had removal of left atrial myxoma. Cardiopulmonary bypass was instituted with aortic and bicaval cannulation. At normothermia, aorta was cross-clamped and continuous coronary perfusion was maintained through an aortic root needle at a rate of 4-6 mL/Kg/minute facilitating a beating heart. Trans-oesophageal echocardiography was routinely deployed. Anaesthetic considerations were focused towards the maintenance of the beating state of the heart, that included, strict control of electrolyte balance, maintenance of adequate perfusion pressure and ST segment monitoring. All the patients could be weaned off cardiopulmonary bypass without defibrillation or significant inotropic support. There was no operative mortality. Open heart surgery on a beating heart for non-coronary cardiac conditions appears to be a good and reproducible option to protect the myocardium from deleterious effects of cardioplegic arrest.