Abnormal sensations evoked over the chest and persistent peri-incisional chest pain after cardiac surgery.

Risk factors for developing Persistent peri-incisional Chest Pain (PCP) after sternotomy are multiple. We examined whether hypoesthesia, hyperalgesia or dysesthesia, evoked in the postoperative period might be associated with PCP after sternotomy. One hundred patients undergoing a sternotomy were evaluated on day 5. Peri-incisional sensory testing was performed using von Frey filament. Presence and severity of PCP were assessed at 2 and 6 months. PCP was present in 29% and 15% of patients respectively at 2 and 6 months. Hyperalgesia on day 5 was present in 43% of patients with PCP at 6 months compared to 15% without PCP. Hypoesthesia was present in 57% of patients with PCP at 6 months compared to 22% without PCP. There was no significant difference in the incidence of dysesthesia. On day 5, hyperalgesia was correlated with a risk to develop PCP at 6 months. Among sensory abnormalities, the presence of hyperalgesia is associated with PCP at 6 months postoperatively.

Cystatin C in cardiac surgery.

Cystatin C has recently been proposed as an alternative marker of glomerular filtration rate. The study compares cystatin C and creatinine concentrations during cardiopulmonary bypass and the first 72 hours postoperatively in patients undergoing coronary artery bypass graft. Forty-nine patients with normal preoperative renal and cardiac function were scheduled for coronary artery bypass graft. Blood was sampled for creatinine and cystatin C measurements at 7 time points till 72 hours postoperatively. Glomerular filtration rate was estimated from calculated clearance using the Cockroft and Gault formula for creatinine and Larsson equation for cystatin C. The baseline values of both markers were within the normal range. Their concentrations were comparable during the whole study period. This was also the case for the calculated creatinine and cystatin C clearance. In patients with normal preoperative renal function undergoing coronary artery bypass graft, measured creatinine concentration remains a cheap and easy way of estimating renal function.

Amrinone in the management of low cardiac output after open heart surgery.

Hemodynamic effects of amrinone were studied in 2 groups of patients after open heart surgery. Group I consisted of 10 patients with moderate heart failure. In the absence of inotropic agents, their mean cardiac index (CI) was 2.02 +/- 0.41 liters/min/m2 and mean pulmonary capillary wedge pressure (PCWP) 19 +/- 3 mm Hg. Amrinone was administered 24 hours postoperatively by bolus injection (2 mg/kg) and by 12-hour infusions (20 micrograms/kg/min). Hemodynamic data and plasma concentrations were obtained 10 and 20 minutes after the bolus injection and at 1, 4, 8 and 12 hours during infusion. Significant beneficial changes were noted in CI, PCWP, right atrial pressure, systemic vascular resistance and pulmonary vascular resistance. Group II consisted of 5 patients in severe cardiogenic shock (mean CI 1.97 +/- 0.3 liters/min/m2, mean PCWP 28 +/- 8 mm Hg) despite adrenergic agonists in all patients and intraaortic counterpulsation in 2. After these measures, amrinone was given intravenously for 36 to 72 hours as additional inotropic support. Significant improvement was observed in CI, PCWP, right atrial pressure, systemic vascular resistance and pulmonary vascular resistance. Four patients in this group were discharged; 1 patient died after 5 days in acute renal failure and coma grade IV. No serious adverse effects of amrinone were observed in any group II patient.(ABSTRACT TRUNCATED AT 250 WORDS)

Nasal continuous positive airway pressure in the perioperative management of patients with obstructive sleep apnea submitted to surgery.

Anesthetic, sedative, and analgesic drugs have been shown in animals and humans to selectively impair upper airway muscle activity. In patients with an already compromised upper airway, these drugs may further jeopardize upper airway patency, especially during sleep. Thus, patients with obstructive sleep apnea syndrome (OSAS) are at high risk for surgery because of the use of the aforementioned drugs in the perioperative period. It has been recommended that such drugs should be avoided or used with extreme caution in patients with OSAS submitted to surgery. We report herein on 16 adult patients with documented OSAS undergoing various types of surgical procedures, including coronary artery bypass surgery. Anesthesia was carried on with the usual type of drugs for each type of surgery. Postoperative opioid analgesia and sedation were not restricted. The first patient, whose OSAS was diagnosed but not treated, died after various complications, including a respiratory arrest in the ward. The second patient experienced serious postoperative complications until a treatment for OSAS with nasal continuous positive airway pressure (N-CPAP) was instituted, and thereafter he made an uneventful recovery. The 14 following patients were started on N-CPAP before surgery, were put on N-CPAP as soon as extubated, on a near-continuous basis, for 24 to 48 h and thereafter for all sleep periods. None of them had major complications. The intensive care unit and hospital stays were the normal ones for each type of surgery in our institution. We conclude that N-CPAP started before surgery and resumed immediately after extubation allowed us to safely manage a variety of surgical procedures in patients with OSAS, and to freely use sedative, analgesic, and anesthetic drugs without major complications. Every effort should be made to identify patients with OSAS and institute N-CPAP therapy before surgery.

Preoperative left ventricular dysfunction and operative risks in coronary bypass surgery.

Preoperative left ventricular function variables were evaluated as potential risk factors for peroperative and postoperative complications in 183 consecutive patients undergoing coronary bypass surgery. Fifty-six patients had no abnormal criteria and 127 had at least one criterion (AN). The incidence of history of infarction was significantly greater in the AN (71.6 percent) than in the N (39.6 percent) group (p less than 0.04). During the early postoperative course, N and AN differentiated significantly in (1) the need for inotropic therapy (II vs 30 percent, p less than 0.05); (2) intra-aortic balloon pump (0 vs 13 percent); (3) arrhythmias (20 and 40 percent, p less than 0.002); and (4) stay in the Intensive Care Unit (2.3 +/- 0.8 and 3.9 +/- 2 days, p less than 0.01). Perioperative necrosis and mortality were not different. During a follow-up period of two years, N and AN did not show any difference in mortality and recurrence of angina.

Dissecting aneurysm of the ascending aorta with aorto-caval fistula. Fiberoptic oximetric findings and surgical management.

A patient presented the rare complication of a dissecting aneurysm of the ascending aorta ruptured into the superior vena cava producing a left-right fistula. Continuous oximetric measurements by a fiberoptic pulmonary artery floated catheter was used to localize the site of the shunt. Emergency surgical repair was successfully performed.

Bacteriologic quality of intraoperative autotransfusion.

Controversies remain about the bacteriologic aspects of intraoperative blood salvage despite the widespread use of this technique. In this prospective study, intraoperative salvaged blood was cultured in 401 patients, according to a direct plating technique. Bacterial growth was detected in 12.7% of cases. These results were compared with those obtained in control studies with sterile water and blood bank units under the same culture conditions. Most microorganisms were coagulase-negative staphylococci, followed by other skin and environmental contaminants. Quantitative estimates of contaminations showed low counts of colony-forming units (CFU/ml): 82% of positive cultures yielded 1 or 2 CFU/ml and 6% had 5 to 20 CFU/ml. Patients were followed up for a minimum of 3 months to detect septic complications. No statistically significant correlation could be found between bacteriologic results of autotransfused blood and infectious complications. This study suggests that bacteriologic monitoring of patients who have undergone autotransfusion may help in detecting surgical field contamination. It also confirms that intraoperative autotransfusion adds little septic risk to cardiac surgery.

Clinical use and bacteriological studies of catheter contamination sleeves.

A system combining a valved introducer sheath and a plastic protective sleeve enabling repositioning of pulmonary artery catheters was tested in 73 cardiac surgical patients. It was used for a mean time of 70.3 h and allowed for improved hemodynamic monitoring. A 12 percent incidence of valve contamination was found and makes the safety of the device questionable.

Clinical evaluation of Duraflo II heparin treated extracorporeal circulation circuits (2nd version). The European Working Group on heparin coated extracorporeal circulation circuits.

OBJECTIVES: To evaluate whether the application of heparin treated circuits for elective coronary artery surgery improves postoperative recovery, a European multicenter randomised clinical trial was carried out. METHODS: In 11 European heart centers, 805 low-risk patients underwent cardiopulmonary bypass (CPB) with either an untreated circuit (n = 407) or an identical but heparin treated circuit (n = 398, Duraflo II). RESULTS: Significant differences were found among participating centers with respect to patient characteristics, blood handling procedures and postoperative care. The use of heparin treated circuits revealed no overall changes in blood loss, blood use, time on ventilator, occurrence of adverse events, morbidity, mortality, and intensive care stay. These results did not change after adjustment for centers and (other) prognostic factors as analysed with logistic regression. In both groups no clinical or technical (patient or device related) side effects were reported. Because female gender and aortic cross clamp time appeared as prognostic factors in the logistic regression analysis, a subgroup analysis with these variables was performed. In a subpopulation of females (n = 99), those receiving heparin treated circuits needed less blood products, had a lower incidence of rhythm disturbances and were extubated earlier than controls. In another subgroup of patients with aortic cross clamp time exceeding 60 min (n = 197), the amount of patients requiring prolonged intensive care treatment (> 24 h) was significantly lower when they received heparin treated circuits versus controls. CONCLUSION: These findings suggest that improved recovery can be expected with heparin treated circuits in specific higher risk patient populations (e.g. females) and when prolonged aortic cross clamp time is anticipated. Further investigations are recommended to analyses the clinical benefit of heparin treated circuits in studies with patients in different well defined risk categories and under better standardised circumstances.

[Somatosensory evoked potentials in patients undergoing circulatory arrest under profound hypothermia]. / Le suivi par potentiels évoqués somesthésiques des patients adultes subissant un arrêt circulatoire sous hypothermie profonde.

The surgical repair of ascending aorta aneurysms can only be carried out under total circulatory arrest, and is consequently to be performed under deep hypothermia, in order to adequately decrease the metabolic requirements of the brain. However, the optimal temperature to be reached is poorly known. SEPs to median nerve stimulation were recorded in 21 operations performed in 20 patients undergoing profound hypothermia. The latencies of all SEP components increase to 21 degrees C. Waves N20 and P14 disappear at mean naso-pharyngeal temperatures of 20 degrees C and 17 degrees C, respectively, although a wide inter-individual variability was observed. We suggest to use the P14 disappearance as the criterion to perform the circulatory arrest: in fact, all surviving patients in whom this criterion was fulfilled recovered without any detectable neurological sequellae, while three patients in whom brain activities disappeared independently on body temperature presented with neurological sequellae. Moreover, particularly if patients presenting with ischemia-induced disappearance of Erb's point activities were excluded, we found a significant correlation between the duration of the circulatory arrest and the delay of N20 and P14 reappearance on rewarming. This confirms the importance of sufficient hypothermia, on the one hand; and on the other hand, our findings imply that, even if SEP monitoring considerably decreases the risk of neurological sequellae associated with these operations, the duration of the circulatory arrest should be reduced as far as possible.

Sequential mammary artery grafts in one hundred and twenty consecutive patients: indications, operative technique, 6 months postoperative functional and angiographic controls.

In the hope of establishing the internal mammary artery (IMA) as a true but superior substitute for the saphenous vein (SV) we reviewed our initial experience in complex IMA grafting. The first 120 consecutive patients, having received at least one sequential IMA graft were analyzed. The length of the IMA pedicle was the only limitation imposed on its use. Technical artifices enhancing the versatility of the IMA are described. The significant peri-operative myocardial infarction rate was 3.3%. There was no cardiac operative mortality, and 1 late mortality (0.8%). Excellent functional results were illustrated by a 2.5% rate of residual angina and dyspnoea. Six months postoperative angiographic controls could be performed in 70% of the patients: all of the sequential mammary conduits were patent, as were 95% of the anastomoses. By contrast 87.2% of the concomitant venous anastomoses were still functioning. With the expanding utilization of the free graft, IMA is expected to become a true, better and all round substitute for the saphenous vein.

Current anesthesia manpower in Belgium in relation to anesthesia work locations.

Two inquiries were conducted in 1995 and 1996 involving all anesthesiology departments in Belgium. The response rate was 57%. One aim of these surveys was to estimate the anesthesia manpower and the number of anesthesia work locations in each hospital, by hospital size and by region. In the operating theater, between 0.77 and 2.24 physicians (full time equivalents) were available per operating room. When considering also anesthesia in remote locations outside the operating theater, and the availability of fully trained physicians and trainees (efficiency estimated as 75% of a fully trained specialist), the ratio decreases to between 0.48 and 1.25, the highest ratios being found in larger hospitals (> 650 beds). When physicians currently in anesthesiology training will have graduated the mean availability of anesthesiologists per anesthesia work station will be 0.87 in Belgium, vs 0.52 in 1996.

Clinical use of continuous monitoring of mixed venous oxygen saturation during and after cardiovascular surgery.

This paper presents the authors' initial experience with a new technique for continuous monitoring of the mixed venous oxygen saturation (SvO2) during and after open heart Surgery. The method uses reflectometric measurements of SvO2 via a fiberoptic pulmonary artery catheter with the capability for thermodilution cardiac output estimates. Changes in SvO2 reflect changes in one or more of the three interacting factors of the Fick equation: arterial oxygen content, cardiac output, and total body oxygen utilization. Intra-and postoperative examples illustrate these various situations. The very short response time of the System allows for early diagnostic and therapeutic decisions.

Mortality and morbidity conferences in a teaching anesthesia department.

In our anesthesia department, Morbidity and Mortality conferences (M & M's) evolved from a well established system of voluntary reporting of anesthesia related incidents. They were however not restricted to accidents solely attributable to anesthesia. Between May 1983 and December 1989, 160 cases were presented, usually by the resident or consultant in charge of the patient at the time of event. The format of conferences is described in detail in this paper. Despite an active selection process, the case mix of presentations closely reflected that of major epidemiological surveys of complications in anesthesia. Residents attending regularly M & M's during the five years of their specialty training got an accurate picture of anesthesia-related mishaps, their mechanisms of onset and their outcome. In particular, the important role played by human intervention was clearly underlined. Due to the selection process, interaction with other physicians or health professionals were described with great frequency in the genesis of accidents anesthetists had to deal with. M & M's proved a valuable teaching tool, but also contributed to improve patient care by revealing faulty routines.

Can we predict the future evolution of anesthesiology workforce in Belgium?

Two models are proposed to predict the evolution of anesthesiology workforce over the next 20 years. Each model features various scenarios according to different assumptions related to future numbers of female anesthetists, working hours, or regulations for postgraduates' working for conditions. However the main uncertainties derive from the unknown evolution of demands. Despite their differences both models agree on several important conclusions: a 13 to 14% shortage of anesthesiologists currently exists to satisfy O.R. demands, this shortage will decrease over the next ten years, and after 2010 a new shortage could arise under the combined pressure of the numerus clausus, of the number of female anesthesiologists and of the aging of the still young population of anesthesiologists.

Heart-transplant and mono-amine oxidase inhibitors.

A case of anesthesia for a heart-transplant operation on a patient on mono-amine oxidase inhibitors (M.A.O.I.) is reported. This 63-year-old farmer was in end-stage cardiac failure due to familial cardiomyopathy. For 24 hours before surgery, he was on a dobutamine infusion (3 mcg/kg/min). He had been taking nialamide (100 mg/day) for 8 years for reactional depression and had not stopped it, despite advice. Anesthesia was induced with etomidate and succinylcholine, and maintained with fentanyl (25 mcg/kg/min) and pancuronium. Cardio-vascular stability was maintained during induction and first stage of surgery, up to cardectomy. Graft ischemia was 188 minutes. Successful defibrillation occurred after verapamil 3 mg. Weaning from C.P.B. was easy with dopamine (5 mcg/kg/min) and isoprenaline (0.01 mcg/kg/min). Post-operatively, on day 1, hypertension appeared and needed a nitroprusside infusion. On day 3, the patient needed another anesthetic for removal of pericardial clots, without problems. He remained very confused and disorientated during all his stay in hospital, but improved greatly with a neuroleptic. He left the hospital on day 28 in a good shape, with an anxiolytic, captopril and immunosuppressors. One month later, he was back on nialamide. The pharmacology of the M.A.O.I. is reviewed and their interactions with anesthesia are discussed as well as the use of inotropes. In this case, the denervated heart-graft, free from M.A.O. inhibition, behaved normally when transplanted in a chronically M.A.O.I. treated recipient.

Should amiodarone be discontinued before cardiac surgery?

Between October 1985 and October 1986, 37 patients, chronically treated with amiodarone, underwent general anesthesia for cardiac, thoracic or vascular surgery. Among them, the 8 non-cardiac surgery patients showed neither intra-, nor postoperative complications. The 29 cardiac surgery patients, had various complications ranging from dysrhythmias (52%), sometimes necessitating a pacemaker (24%), to marked and even fatal vasoplegia. We describe the only fatal case and compare our complication rate with that described in the available literature. Most complications could be symptomatically treated. In addition, amiodarone has a very long elimination half-life: therefore withdrawal before surgery implies delaying operations by several weeks, and puts patients at increased risk of malignant dysrhythmias. However, fatal vasoplegia does occur, and its real incidence should be assessed by a broader survey.

Blood transfusion practice in Belgium. As assessed by a national survey.

In April 1995 the Ministry of Public Health invited all Belgian hospitals to participate to a survey on the use of blood transfusion. The questionnaire presented two parts, the first one devoted to products transfused and the second one to the transfusion organisation in the hospital. 71 hospitals answered: 7 university and 64 general hospitals. All hospitals reported the use of red cells, 31 of them still used whole blood. Surgical departments transfused the greatest absolute amount of units, but the highest intensity (units/bed/year) was observed in intensive care units. 52 hospitals mentioned the use of autologous predeposit. The highest consumption of platelets occurred in medicine but intensive care showed the highest intensity of platelet transfusion. In 41 hospitals platelets were obtained by cytapheresis. The number of plasma units transfused was highly correlated with the quantities of packed red cells and whole blood transfused. Ten hospitals didn't report the use of any blood conservation technique. Returning unused units to the blood bank was allowed in 80% of the hospitals, their return to the transfusion center was permitted in 65% of the hospitals. A transfusion committee existed in only 11 hospitals. Transfusion should be improved by a better education of all physicians and nurses involved with transfusion and by improving standardisation, by better documentation, better reporting and information of all health care workers involved.

Systematic use of aprotinin in cardiac surgery: influence on total homologous exposure and hospital cost.

To assess the impact of systematic use of aprotinin, 115 consecutive adults undergoing cardiac surgery were randomly allocated with a sealed envelope technique. Treated (T) patients (n = 58) received 2.10(6) Kallikrein Inactivating Units (KIU) before incision, 2.10(6) prior to bypass, and 5.10(5) KIU.hr-1 for 5 hrs, whereas control (C) cases (n = 57) received nothing. Surgeons, perfusionists, ICU and ward physicians were blinded. Postoperative blood loss decreased from 1198 ml (C) to 698 ml (T) (p less than 0.001). Total transfusional needs were 7.25 (C) and 4.9 (T) units (p less than 0.01), where from 65% were autologous in group T, versus 51% in group C (p less than 0.02). Total homologous exposure decreased from 4.5 (C) to 2.7 (T) units on the average, from 3 to 1 units as a median (p less than 0.01). Multiple Stepwise Regression Analysis showed treatment as the most important variable influencing postoperative blood loss, but duration and type of procedures were more important to explain transfusion needs. Both groups were comparable for other pre- and intra-operative variables. For coronary operations (n = 75), aprotinin showed the strongest negative association with blood loss, the number of arterial conduits being the second influencing variable. No evidence was found for increased early graft thrombosis. The average hospital bill was 9% lower in the treated group, an unexplained finding needing independent confirmation.

[Risk factors in surgery of the abdominal aorta]. / Facteurs de risque en chirurgie de l'aorte abdominale.

Surgical risk factors of abdominal aortic disease. Between January 1, 1982 and October 1986, 327 surgical repairs were performed on abdominal aortic obstructive diseases and aneurysms at the St. Luc University Hospital. 150 pre-, per- and postoperative data were collected retrospectively for each patient. Ninety-one per cent of patients were smokers, 57.5 per cent had heart disease, 43 per cent arterial hypertension, 51 per cent peripheral vascular disease and 28 percent had obstructive lung disease. Concerning cardiac morbidity, the post-operative infarction rate was 4.4 per cent in patients who had previously suffered from an infarction, and 1.9 per cent in patients with no previous infarction. Post-operative angina-ischemia rate were respectively 23 and 4.7 per cent. Two hundred and thirty two elective operations resulted in 6 deaths (2.6 per cent) while 95 emergency operations resulted in 34 deaths (35.8 per cent). The causes of the death and the post-operative complications are detailed. The decrease of the morbidity and the mortality rates inherent to this pathology depends on an early diagnosis and surgical treatment by a team, knowledgeable of this pathology, who are able to prevent and correctly treat the complications, especially those affecting the cardiovascular system.