The role of the priming fluid in the metabolic response to cardiopulmonary bypass in children of less than 15 kg body weight undergoing open-heart surgery

The major metabolic response to open-heart surgery using cardiopulmonary bypass has been shown in adults to be modified by the components of the pump priming fluid. This effect is likely to be more significant in children. Data on 29 children less than 15 kg body weight are presented. Patients were randomised to receive a prime containing one of three crystalloid priming fluids: 100% Hartmann's (H), 50% Hartmann's + 50% 5%-Dextrose (HD), or 100% Plasmalyte 148 (P). The remainder of the prime was CPD stored blood and the prime was buffered with sodium bicarbonate. Severe hyperglycaemia 22.4 +/- 1.3 mmol/l occurred during bypass in the HD group but moderate hyperglycaemia occurred in the other prime groups. Hyperlactataemia occurred in all prime groups during bypass and was highest in the H prime group at 3.9 +/- 0.4 mmol/l. These changes in intermediary metabolites were only partly explained by the crystalloid components of the priming fluid. A subsiduary study revealed the important contribution of CPD stored blood to those intermediary metabolite concentrations. Therefore, the well recognised changes in intermediary metabolites as components of the metabolic response to surgery, namely hyperglycaemia and hyperlactataemia were augmented by the composition of the priming fluids. In addition, CPD stored blood and the sodium bicarbonate buffer increased the sodium concentration of the prime to hypernatraemic levels in both the H and P groups which caused an increase in sodium concentration during bypass. Therefore important changes during bypass occur as a direct result of the individual components of the priming fluid. These changes may result in osmolal flux, hyperglycaemia and hyperlactataemia, all of which have been reported to be potentially harmful.

Surgery for congenital abnormalities of the mitral valve at the Hospital for Sick Children, London from 1969-1983

The surgical management of congenital mitral valve (MV) anomalies remains controversial and complex. Valve repair has been said to be preferable to valve replacement. To assess the validity of this suggestion we have reviewed our experience of these procedures at The Hospital for Sick Children, Great Ormond Street, London from 1969-1983. In that time 48 patients have undergone surgery; in 23 repair was practicable (Group A) and in 25 replacement of the MV was required (Group B). Group A patients were slightly older than group B patients (5.9 +/- 1.0 years (SEM) vs 3.6 +/- 0.5 years). Björk Shiley valves were the predominant prosthesis used. Overall mortality was 33%, with 17% in Group A and 48% in Group B. Hospital mortality was 4.5% in Group A and 28% in Group B. Actuarial survival for Group A was 90% at 1 year, and 75% at 2 and 5 years; for Group B it was 52% at 1 and 2 years and 42% at 5 years. Mortality was significantly higher in those aged less than 5 years. Four patients in Group A have required re-operation, in 3 valve replacement was required; 2 of these died in hospital. One patient in Group B has required reoperation for valve-related thromboembolism. Three patients are awaiting replacement of calcified bioprostheses. These data support the concept that repair of MV should be performed where possible. The severity of the anomalies was greater in Group B and a rethink as to whether valve replacement is the best option for severe mitral stenosis in those aged less than 5 years seems indicated, in view of the very high mortality.

Congenital left ventricular inflow obstruction: is the outcome related to the site of the obstruction?

Between 1978 and 1987, 39 patients aged 1 day to 15 years underwent surgery for symptomatic left ventricular inflow obstruction. Four diagnostic groups were identified: cor triatriatum (6 patients), supravalvar mitral membrane (SVMM) with a normal mitral valve (7 patients), SVMM with an abnormal mitral valve (9 patients) and mitral stenosis (17 patients). Associated cardiac anomalies occurred in 26 patients (67%). There were 8 deaths (21%), 3 in patients with SVMM and an abnormal mitral valve and 5 in patients with mitral stenosis. Survival for patients with normal mitral valves was significantly better than that for patients with abnormal mitral valves (13/13 vs 18/26, P less than 0.05). There was also high morbidity in patients requiring prosthetic mitral valve replacement. These data suggest that the outcome of surgical treatment for left ventricular inflow obstruction may be predicted according to the site of the obstruction. This is best determined preoperatively by cross-sectional echocardiography which allows optimal planning of surgical strategy.

Coarctation of the aorta with arch hypoplasia: improvements on a new technique

The association between coarctation and arch hypoplasia can be difficult to manage surgically. Several complex techniques have been designed for its management (e.g., resection of coarctation with either retrograde subclavian flap or carotid subclavian angioplasty). However, residual gradients are frequent. Recently, a new technique of extensive end-to-end anastomosis was described that has the advantages of leaving the left subclavian artery intact and resulting in a wide anastomosis. The present report details a modification of this technique, which more extensively dissects the arch branches and clamps the aortic arch almost 50% of the way across the innominate branch. The descending aorta is mobilized to the diaphragm. Anastomosis is completed with 7-0 PDS or polypropylene sutures. This type of repair has been performed in 7 patients, with a maximum residual gradient at the end of the procedure of 5 mm Hg. These modifications represent an excellent option to the surgeon in the management of this difficult clinical entity.

The metabolic load of stored blood. Implications for major transfusions in infants

Plasma electrolyte, intermediary metabolite, and hormone concentrations were measured in samples of 110 units of citrate phosphate dextrose blood being used for clinical transfusions. The most important changes from the physiological range were in sodium, potassium, glucose, and lactate concentrations. Mean sodium concentrations fell from 170 mmol/l at the beginning of storage to 156 mmol/l at the end and mean potassium concentrations rose from 7 mmol/l to 25 mmol/l. Glucose had a mean concentration of 20 mmol/l at the beginning of storage and had only fallen to 15 mmol/l at the end. Mean lactate concentrations increased from 7 mmol/l at the beginning of storage to 25 mmol/l at the end. Many samples had cortisol, insulin, and growth hormone concentrations within the physiological range. Citrate phosphate dextrose blood contains a large substrate load that changes during storage and that should be taken into account when infants are transfused large volumes of blood. The strong correlation coefficients with duration of storage for sodium, potassium, and lactate (-0.71, 0.91, and 0.90, respectively) indicate that concentrations of these substrates can be predicted within a narrow range if the duration of blood storage is known.

The ontogeny of placental Na+-K+ ATPase in the mouse and its impairment by ethanol

We have investigated the normal ontogeny of Na+-K+ ATPase in the mouse placenta and the possibility that impairment in placental transport capacity, as reflected in reductions in NA+-K+ ATPase activity, is associated with alcohol-related embryonic growth restriction. We have demonstrated that over the normal course of pregnancy there is a dramatic increase in placental NA+-K+ ATPase activity which occurs in concert with the embryofetal body growth spurt. Maternal ethanol administration during the early period of placental enzymogenesis (days 7-9) resulted in a significant reduction (up to 40%) of placental Na+-K+ ATPase activity on day 15. Both the severity and the frequency of the reduction were dose dependent. The effect was associated with significant reductions in embryonic body and brain weight but no change in body length or prenatal mortality. Incubation of term placental fragments for 2 h in increasing concentrations of ethanol resulted in a comparable reduction in enzyme activity. Our studies demonstrate that direct ethanol exposure produces a reduction of placental Na+-K+ ATPase activity, that exposure during the early stages of enzymogenesis results in persistent reductions in Na+-K+ ATPase activity in the mature placenta, and that this effect is associated with deficits of embryonic body and brain growth. A direct causal relationship has not been proven; however, it is conceivable that the correlation between reduced placental Na+-K+ ATPase activity and impaired embryofetal growth reflects a common causal pathway.

Diabetes mellitus and open heart surgery. A simple, practical closed-loop insulin infusion system for blood glucose control

A method, based on bedside determinations of blood glucose by nursing staff, was designed to control the administration of insulin to diabetic patients during and following open heart surgery. A computer-controlled intravenous infusion pump was used to deliver the insulin. Excellent control of the hyperglycaemia normally associated with open heart surgery was achieved, with 84 percent of measured blood glucose values falling within 2 mmol/litre of the target value of 6 mmol/litre. The method proved to be simple, effective, and safe.

Ocular changes in the mouse embryo following acute maternal ethanol intoxication

The development of the eye was investigated in the mouse embryo following a single administration of ethanol plus [3H]thymidine to the dam on day 13 of gestation. After 1 hr there was no difference in the number of labelled cells/100 micron 2 in the neural layer of the retina compared to controls, but there was an alcohol-related reduction in labelling density. After 24 hr there was an increase in the numbers of both pyknotic cells and mitotic figures, breaks occurred in the inner surface of the retina and cell debris was being extruded into the posterior chamber. At 48 hr the increase in pyknotic cells persisted, but there was less evidence of cell debris and the borders had been repaired. The estimated cell cycle time in the neural progenitor cells following maternal alcohol administration was increased 7-fold compared to controls. Morphometric analysis revealed that after 48 hr there were significant alcohol-related reductions in the width and depth of the eye, in the thickness of the neural layer and in the interocular distance. It appears that many of the ophthalmic abnormalities reported in human fetal alcohol syndrome can be produced in the mouse embryo following a single episode of acute maternal intoxication during a critical period of ocular ontogeny, and that they evolve primarily from disturbances in the normal patterns of recruitment and loss of neural progenitor cells in the developing retina.

The cardiopulmonary bypass pump-priming fluid and nitrogen balance after open-heart surgery in adults

Different crystalloid cardiopulmonary bypass pump-priming fluids provide very different substrate loads to patients undergoing open-heart surgery. As a result they may modulate the endocrine milieu, and thus might be expected to alter postoperative nitrogen balance. To test this hypothesis, 24 adult patients undergoing open-heart valve surgery were randomized into four matched groups each to receive a different prime, namely: Hartmann's solution, Plasmalyte 148R, Solution 11 R and a prime consisting of equal volumes of Hartmann's solution and 5% dextrose. Accurate nitrogen balance studies were obtained each 24 hours from one day preoperatively to seven days postoperatively.

The results obtained demonstrated that postoperative nitrogen balance was unaffected by the nature of the crystalloid pump prime. Nitrogen balance in the patients studied was better than that reported from other centres in similar patients.

The effects of four different crystalloid bypass pump-priming fluids upon the metabolic response to cardiac operation

The crystalloid solutions used to prime cardiopulmonary bypass pumps frequently contain metabolically active substrates. However, there is a lack of controlled studies to investigate the metabolic response to cardiac operations using different pump primes. We have carried out a prospective, randomized study of 24 patients divided into four groups, each group receiving a different crystalloid prime. The primes contained glucose, lactate, glucose and lactate, or neither glucose nor lactate. Using identical anesthetic, surgical, and perfusion techniques, we estimated the metabolic response to cardiac operation in all patients by frequent blood sampling for measurement of hormone (insulin, glucagon, cortisol, and growth hormone) and metabolite concentrations (glucose, lactate, pyruvate, glycerol, alanine, and 3-hydroxybutyrate) from the day before operation to the seventh postoperative day. The results demonstrated that, after 4 hours postoperatively, the endocrine and metabolic response to cardiac operation was unaffected by the nature of the priming fluid. However, major endocrine and metabolic changes occurred before that time, which were related directly to the glucose and lactate contents of the prime. Very high concentrations of both glucose and lactate were observed at the end of bypass if they were induced in the prime. Given the known dangers of hyperglycemia in cerebral ischemia and the potential gluconeogenic effects of infused lactate, we suggest that glucose-free and lactate-free primes be employed in the extracorporeal circuit.

Perforation of intrathoracic colon causing acute pneumothorax

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Primary adenocarcinoma of the gastro-oesophageal junction in childhood. A case report

Primary adenocarcinoma of the gastro-oesophageal junction, oesophagus or stomach is very rare in childhood (3, 5). Within that small patient population, dysphagia is an unusual presenting feature. We wish to report such a condition, occurring in a 14-year-old boy, to emphasise that dysphagia in childhood should always be taken seriously.

Insulin delivery during surgery in the diabetic patient

The usual treatment of diabetic patients during surgery with general anesthesia owes little to logic, common sense, or knowledge of requirements, and mortality and morbidity remain high in many centers. In the nondiabetic patient, surgery is accompanied by a rise in secretion of catabolic hormones, insulin-resistance and loss of protein. Therapy of the diabetic patient should be designed to account for these changes and to avoid hypoglycemia, hyperglycemia, and hyperketonemia. It is suggested that for major operations for well-controlled non-insulin-dependent diabetic (NIDDM) persons and for all minor and major operations for insulin-dependent diabetic (IDDM) persons and poorly controlled NIDDM, a combined insulin (3.2 U/h), glucose (10 g 10% dextrose/h), and potassium infusion should be used until oral feeding recommences. The insulin dose should be modified periodically according to bedside glucose monitoring. Fluids should be used as in nondiabetic patients, except that lactate-containing solutions should be avoided. Insulin requirements will be increased (1) by infection, (2) in patients with hepatic disease, (3) in obese patients, (4) in steroid-treated patients, and (5) during cardiovascular surgery. A diabetes-care team should preferably be responsible for the care of the diabetic pre-, per-, and postoperatively.

Anterior tibial compartment syndrome associated with ergotamine ingestion

This is the first reported case of acute anterior tibial compartment syndrome following ergotamine tartrate overdosage. A 25-year-old man developed signs and symptoms of ergotism after ingestion of 72 mg of ergotamine tartrate over the 12 days prior to his hospital admission. On the fourth hospital day, the patient developed bilateral anterior tibial compartment syndrome. The development of this syndrome is postulated to have been due to the progressive edema and tissue pressure in the anterior tibial compartments, worsened by the gradual improvement of the peripheral circulation which followed the diminished vasopastic effect of the ergotamine.