Failure of normal glycaemic regulation in a patient with severe hypothermia

This report describes the case of an 88-year-old non-diabetic female who presented to the emergency department following a presumed hypoijtycaemic collapse due to self-neglect. Subsequent rewarming and resuscitation demonstrated a number of the significant consequences of severe hypothermia, including apparent secondary impairment of glycaemic autoregulation. The phenomenon of reversible inhibition of insulin secretion due to severe hypothermia has been documented previously in the field of cardiac surgery. The hyperglycaemia was not treated with any antihyperglycaernic agent, and her recovery was uneventful. Subsequent blood sugar level monitoring was normal. If insulin is administered to the hypothermic patient, intensive monitoring of blood glucose is essential due to the increase in endogenous insulin secretion on rewarming. (c) 2005 Elsevier Ireland Ltd. All rights reserved.

Surgical programme at Royal Alexandra Hospital, Sydney, for Papua New Guinea children with congenital heart disease, 1978-1994

Objective : To report the history of the Royal Alexandra Hospital for Children (RAHC) Papua New Guinea (PNG) cardiac surgical programme and describe the selection, preoperative clinical features and postoperative outcome of children with congenital heart disease managed by the programme. Methods : Details for each of the PNG cardiac patients admitted to RAHC following selection by visiting cardiologists between 1978 and 1994 were entered into a database, and analysed and interpreted. Results : A congenital heart defect was confirmed in 165 of the 170 children selected. The male to female ratio was 1:1 and the mean age on admission to RAHC was 5.5 years. Almost all of the children for whom data were available (98%) had a weight for age and 41% had a height for age less than the 3rd centile. One-sixth had delayed milestones. A large number were tachypnoeic, in heart failure, or had pulmonary hypertension on admission. Ventricular septal defect and tetralogy of Fallot were the commonest defects, and lesions such as aortic stenosis, coarctation of the aorta and transposition of the great arteries were absent or rare. Thirty-one (19%) of the children selected initially did not receive surgery because of pulmonary hypertension, or because the lesions did not fall within the programme guidelines for operation. One hundred and twenty-nine children had corrective and four had palliative procedures. Half of the operated children had postoperative complications. Eight children died, all following open-heart procedures, giving a case fatality rate of 6%. Preoperative tachypnoea, hepatomegaly, cardiac failure and pulmonary hypertension were strongly associated with poor outcome. Conclusions : The programme was an arduous exercise for all organizations concerned, but achieved comparatively good short-term outcomes. The experience gained should assist in planning for similar programmes.

Amiodarone - waxed and waned and waxed again

Amiodarone has been used as an anti-arrhythmic drug since the 1970s and has an established role in the treatment of ventricular tachyarrhythmias. Although considered to be a class III anti-arrhythmic, amiodarone also has class I, II and IV actions, which gives it a unique pharmacological and anti-arrhythmic profile. Amiodarone is a structural analogue of thyroid hormone and some of its anti-arrhythmic properties and toxicity may be attributable to interactions with nuclear thyroid hormone receptors. The lipid solubility of amiodarone gives it an exceptionally long half-life. Oral amiodarone takes days to work in ventricular tachyarrhythmias, but iv. amiodarone has immediate effect and can be used in life threatening ventricular arrhythmias. Intravenous amiodarone administered after out-of-hospital cardiac arrest due to ventricular fibrillation improves survival to hospital admission. Many survivors of myocardial infarction (MI) die during the subsequent year, probably due to ventricular arrhythmia. Amiodarone reduces sudden death after MI and this benefit is predominantly observed in patients with preserved cardiac function. Sudden cardiac death, predominantly due to ventricular arrhythmias, is also commonly seen in patients with heart failure. The Grupo de Estudio de la Sobrevida en lsuficiencia Cardiaca en Argentina (GESICA) and Estudio Piloto Argentino de Muerte Subita y Amiodarona (EPAMSA) trials showed survival benefit of amiodarone in heart failure, whereas Congestive Heart Failure-Survival Trial of Anti-arrhythmic Therapy (CHF-STAT) did not. Subsequent meta-analysis established a survival benefit of amiodarone in heart failure. Implanted Cardioverter Defibrillators (ICDs) also give survival benefit to patients at risk of sudden death. In patients with a history of ventricular fibrillation or haemodynamically-compromising ventricular tachycardia, ICDs have been shown to be superior to anti-arrhythmic drugs, principally amiodarone. Further analysis has been undertaken to ascertain which patients are most likely to benefit from ICDs, as these are more expensive than treatment with amiodarone. Patients with severely depressed ejection fractions should be the first to be considered for ICDs. A new indication for amiodarone is atrial fibrillation or flutter. Amiodarone is effective in chronic and recent onset atrial fibrillation and orally or iv. for atrial fibrillation after heart surgery. In atrial fibrillation amiodarone is more than or equi-effective with flecainide, quinidine, racemic sotalol, propafenone and diltiazem and therefore should be considered for first line therapy. Amiodarone is also safe and effective in controlling refractory tachyarrhythmias in infants and is safe after cardiac surgery.

Experiences with redo aortic valve surgery

Objectives and Methods: Reoperations are an integral part of a cardiac surgeon's practice. We share our experience of 546 reoperations over the last 21 years to January 2000, with the focus directed towards the timing of reoperation, reducing the mortality and morbidity of reoperation and rereplacement aortic valve surgery, and understanding the important risk factors. In addition, the precise technical steps that facilitate careful successful explantation of various devices (allograft, stented and stentless xenografts, and mechanical valves) are detailed. Results: Optimal planned reoperation before deterioration to New York Heart Association Class III/IV levels and before unfavorable cardiac and comorbidity general system failure occurs has produced low mortality and morbidity as compared with first operation results. However, unfavorable delays and late rereferral result in mortality rates of up to 22% for emergency redo AVR for degenerated bioprostheses. Conclusion: Cardiac surgical units have the opportunity to establish a closer patient-surgeon relationship, which favors, when necessary, the optimal timing of reoperation. Knowledge of the more important risk factors and adherence to specific technical steps at explantation of various devices enhances satisfactory reoperation outcomes.

A case report of acute heart failure caused by a patient delaying taking his diuretic medication

Acute heart failure is a life-threatening medical emergency, most commonly occurring as an immediate or delayed complication of acute myocardial infarction (AMI), or resulting from severe hypertension or valvular defects (stenosis or incompetence). Occasionally it is caused by patients' non-compliance with medication orders. In this case the patient had a history of three previous AMIs, controlled hypertension, and controlled congestive heart failure (CHF) for which he took two 40mg frusemide tablets (a very potent oral diuretic) each morning. Because he had experienced bladder discomfort during the latter stages of previous appointments he decided to delay taking the diuretic until after his appointment an acute heart failure ensued.

Chest pain in the dental surgery: A brief review and practical points in diagnosis and management

If a dental patient develops chest pain it must always be managed promptly and properly, i.e., the practitioner immediately stops the procedure and, being aware of the patients's medical history, questions the patient regarding the nature of the pain to help determine the likely diagnosis. It will most likely be a manifestation of coronary artery disease (synonymous with ischaemic heart disease), i.e., angina pectoris or acute myocardial infarction, most usually the former. Angina will usually resolve with proper intervention whereas up to about one-half of myocardial infarction cases will develop cardiac arrest, mostly in the first few hours, and this will be fatal in up to two-thirds of cases. As health care professions, dental practitioners have an inherent duty of care to be able to initiate appropriate care if such a medical emergency occurs.

Usefulness of clinical risk markers and ischemic threshold to stratify risk in patients undergoing major noncardiac surgery

The risk of cardiac events in patients undergoing major noncardiac surgery is dependent on their clinical characteristics and the results of stress testing. The purpose of this study was to develop a composite approach to defining levels of risk and to examine whether different approaches to prophylaxis influenced this prediction of outcome. One hundred forty-five consecutive patients (aged 68 +/- 9 years, 79 men) with >1 clinical risk variable were studied with standard dobutamine-atropine stress echo before major noncardiac surgery. Risk levels were stratified according to the presence of ischemia (new or worsening wall motion abnormality), ischemic threshold (heart rate at development of ischemia), and number of clinical risk variables. Patients were followed for perioperative events (during hospital admission) and death or infarction over the subsequent 16 10 months. Ten perioperative events occurred in 105 patients who proceeded to surgery (10%, 95% confidence interval [CI] 5% to 17%), 40 being cancelled because of cardiac or other risk. No ischemia was identified in 56 patients, 1 of whom (1.8%) had a perioperative infarction. Of the 49 patients with ischemia, 22 (45%) had 1 or 2 clinical risk factors; 2 (9%, 95% CI 1% to 29%) had events. Another 15 patients had a high ischemic threshold and 3 or 4 risk factors; 3 (20%, 95% Cl 4% to 48%) had events. Twelve patients had a low ischemic threshold and 3 or 4 risk factors; 4 (33%, 95% CI 10% to 65%) had events. Preoperative myocardial revascularization was performed in only 3 patients, none of whom had events. Perioperative and long-term events occurred despite the use of beta blockers; 7 of 41 eta blocker-treated patients had a perioperative event (17%, 95% CI 7% to 32%); these treated patients were at higher anticipated risk than untreated patients (20 +/- 24% vs 10 +/- 19%, p = 0.02). The total event rate over late follow-up was 13%, and was predicted by dobutamine-atropine stress echo results and heart rate response. (C) 2002 by Excerpta Medica, Inc.

Quality assurance of paediatric cardiac surgery: A prospective 6-year analysis

Objective: To audit effective quality assurance methods to monitor outcomes following paediatric cardiac surgery at a single institution. Methods: All patients undergoing cardiac surgery from January 1996 to December 2001 were enrolled prospectively. Patients were stratified by complexity of surgical procedure into four groups, with Category 4 being the most complex procedure. Outcome measures included death, length of admission and morbidity from complications. Results: A total of 1815 patients underwent 1973 surgical procedures. Of these, 1447 (73.3%) were cardiopulmonary bypass procedures, and 543 (27.5%) were more complex (Category 3 and 4) procedures. Median patient age was 3.5 years (range, 1 day-20 years) and patient weight 15.0 kg (range, 900 g to 90 kg). Sixty-six patients (3.6%) died during the study period. Of the procedures in 1996, 22.7% were classified as complex compared with 29.2% of procedures in 2001. The annual surgical mortality ranged from 1.9-4.7% (P=0.20), and when mortality was adjusted for complexity of surgery, there was no significant yearly variation in the mortality rate (P=0.57). Analysis of individual surgeon's results showed no significant difference in the mortality rate by complexity of surgery performed (P=0.90). Mean ventilation times did not change significantly over time (P=0.79). The yearly incidence of significant neurological complications ranged from 0.6% to 4.5% and the incidence of arrhythmias from 4.2% to 8.0%. No difference was detected between the years. Conclusions: Stratifying complexity of surgery proved valuable in monitoring surgical outcomes and detecting differences in performance over time as large subgroups were created for analysis.

Carvedilol reduces the costs of medical care in severe heart failure: An economic analysis of the COPERNICUS study applied to the United Kingdom

Background: The aim of this study was to determine the effects of carvedilol on the costs related to the treatment of severe chronic heart failure (CHF). Methods: Costs for the treatment for heart failure within the National Health Service (NHS) in the United Kingdom (UK) were applied to resource utilisation data prospectively collected in all patients randomized into the Carvedilol Prospective Randomized Cumulative Survival (COPERNICUS) Study. Unit-specific, per them (hospital bed day) costs were used to calculate expenditures due to hospitalizations. We also included costs of carvedilol treatment, general practitioner surgery/office visits, hospital out-patient clinic visits and nursing home care based on estimates derived from validated patterns of clinical practice in the UK. Results: The estimated cost of carvedilol therapy and related ambulatory care for the 1156 patients assigned to active treatment was 530,771 pound (44.89 pound per patient/month of follow-up). However, patients assigned to carvedilol were hospitalised less often and accumulated fewer and less expensive days of admission. Consequently, the total estimated cost of hospital care was 3.49 pound million in the carvedilol group compared with 4.24 pound million for the 1133 patients in the placebo arm. The cost of post-discharge care was also less in the carvedilol than in the placebo group (479,200 pound vs. 548,300) pound. Overall, the cost per patient treated in the carvedilol group was 3948 pound compared to 4279 pound in the placebo group. This equated to a cost of 385.98 pound vs. 434.18 pound, respectively, per patient/month of follow-up: an 11.1% reduction in health care costs in favour of carvedilol. Conclusions: These findings suggest that not only can carvedilol treatment increase survival and reduce hospital admissions in patients with severe CHF but that it can also cut costs in the process.

Asymptomatic long-term survivors of coronary artery bypass surgery enjoy a quality of life equal to the general population

Background Health-related quality of life (HRQOL) among long-term survivors of coronary artery bypass surgery is an important outcome that has been little studied at the population level. Methods A postal survey was conducted in 1999 to 2000 in patients 6 to 20 years after coronary artery bypass graft (CABG) surgery in Western-Australia. A random stratified sample of 2500 was drawn from 8910 patients who had their first CABG surgery in 1980 to 1993. Health-related quality of life was measured with Short Form 36 and EuroQol visual analogue scale. Results Response was 82% (n = 2061). Health-related quality of life declined with age and was similar for men and women, although scores for women were worse for physical functioning. Compared with Australian population norms, the age- and sex-standardized scores of survivors of CABG were generally worse, mainly in the physical domain. Reported angina at the time of follow-up (33%), symptoms of heart failure equivalent to New York Heart Association (NYHA) classes II to IV (34%), and comorbidities such as diabetes and hypertension were associated with poorer HRQOL. For both men and women without angina or heart failure at follow-up, HRQOL was no different from that of the general population. Conclusion Overall, the quality of life among long-term survivors of CABG is worse than that of the general population, the difference being mainly attributable to recurrent symptoms and comorbidities. Quality of life for those without angina or heart failure at follow-up was equivalent to the population norms, providing an incentive to maximize efforts to abolish angina and ameliorate heart failure symptoms.

Prognostic indicators for open globe injury

Background: The purpose of the study is to identify factors predictive of outcome after open globe injury in 273 patients admitted to the Royal Brisbane Hospital, Queensland, Australia between 1992 and 2003. Methods: Data were collected retrospectively regarding demographic and geographical factors, injury circumstances, initial visual acuity (VA), injury parameters, details of initial and subsequent surgery, final best corrected VA and complications. Multivariate analysis using binary logistic regression was utilized to identify which factors were related to outcome. Results: 83% of patients were male, with a mean age of 38.3 years. The mean duration of follow up was 16.6 months and 58% of patients (135 of 231) achieved an overall improvement in their vision. Forty-one cases (15%) were enucleated, with half of these cases performed primarily. The prognostic factors indicating the likelihood of a VA of counting fingers or worse were poor initial VA, a large laceration > 10 mm and the presence of a relative afferent pupil defect. Rural patients had a significantly worse final VA than city dwellers and had higher rates of endophthalmitis and enucleation. Conclusions: Assessment of prognostic factors at the time of presentation of an open globe injury enables realistic expectations of final visual outcome by the doctor and the patient. In order to improve outcomes in patients from rural areas, access to specialized eye services need to be upgraded.

The use of recombinant activated factor VII for refractory bleeding post complex cardiothoracic surgery

We reviewed the outcome following use of recombinant activated factor VII (rVIIa) in patients with major bleeding post cardiothoracic surgery in our unit between January 2002 and July 2004. The unit consists of 16 cardiothoracic intensive care beds in a public metropolitan teaching hospital which serves as a referral centre for heart and lung transplant surgery Patients with refactory bleeding following cardiothoracic surgical procedures who were treated with rVIIa were identified. A total of 12 episodes of rVIIa use were recorded in ten patients, including three episodes with ventricular assist devices, and 5 heart and/or lung transplants. The median dose used was 85 mu g/kg. Chest tube drainage decreased in all patients following administration of rVIIa; median chest tube drainage decreased front 445 ml/h to 171 ml/h (P=0.03). Despite cessation of bleeding, mortality was high, when rVIIa was used after more than 24 hours. In six episodes, despite early rVIIa use (within six hours), continued bleeding necessitated return to theatre, where a surgical source of bleeding was found. In this small retrospective study, rVIIa significantly reduced bleeding that was refractory to standard blood product transfusion. In this series of patients., those that did not respond to rVIla early in the postoperative phase were found to have a surgical source of bleeding.