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.

Guidelines for the transfusion of red cells.

The following recommendations, which aim at standardising and rationalising clinical indications for the transfusion of red cells in Belgium, were drawn up by a working group of the Superior Health Council. To this end, the Superior Health Council organised an expert meeting devoted to "Guidelines for the transfusion of red cells" in collaboration with the Belgian Hematological Society. The experts discussed the indications for red cell transfusions, the ideal red cell concentrate, the practical issues of administering red cells, and red cell transfusions in patients in a critical condition. The recommendations formulated by the experts were validated by the working group with the purpose of harmonising red cell transfusion in Belgian hospitals.

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.

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.

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.

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.

The use of somatosensory evoked potentials to determine the optimal degree of hypothermia during circulatory arrest.

We sequentially recorded subcortical (P14) and cortical (N20) somatosensory evoked potentials (SEPs) in 32 patients undergoing deep hypothermic circulatory arrest (CA). Under normal hemodynamic conditions, hypothermia initially produced N20 disappearance at a mean nasopharyngeal temperature of 20.4 +/- 2.6 degrees C (range 14.5 to 26.1 degrees C) and P14 disappearance at a mean of 16.9 +/- 2.0 degrees C (range 12.4 to 20.2 degrees C). On rewarming, P14 reappeared at mean temperature of 19.3 +/- 4.0 degrees C (range 13.5 to 29.2 degrees C) and N20 at a mean of 21.1 +/- 4.1 degrees C (range 14.3 to 29.6 degrees C). The delay of SEP reappearance after restoration of blood flow correlated significantly with CA duration (r = 0.74 for P14, and r = 0.62 for N20; p < 0.01). Neurological recovery was uneventful in 23 patients; 5 patients presented with neurological sequelae (minor or transient in 4; no recovery from anesthesia and death after 48 hours in 1), and 4 patients died during operation. Twenty-three of 24 surviving patients in whom P14 disappearance was the criterion that hypothermia was deep enough to perform CA (duration: 17 to 94 min) had a normal neurological outcome. By contrast, all surviving patients in whom cortical SEPs disappeared at higher temperatures presented neurological sequelae. In conclusion, the neurophysiological monitoring of brain stem activity, as specifically provided by SEPs, enables determination of the optimal temperature for CA, and demonstrates superiority of SEP monitoring over the use of EEG.

Autologous blood donation before myocardial revascularization: a Holter-electrocardiographic analysis.

The influence of preoperative autologous blood donation on myocardial ischemia and arrhythmias was evaluated in 24 patients scheduled for coronary artery bypass grafting (CABG). All had a Holter recorder placed 24 hours before predonation (day 1), the cassette was changed prior to donation, and the recording continued for 24 hours thereafter (day 2). Each patient served as his or her own control, and observations made on day 2 were compared with those of day 1. Ischemia was quantitated by calculating the duration (C.Dur.) and the area (C. Area) of ischemic ST segment depressions, and ventricular premature beats (VPB) were classified according to the Lown grading system. Twenty-one men and 3 women were monitored. On day 1, 9 patients had 20 ischemic events, 3 being symptomatic. Nine patients demonstrated ischemia on day 2, representing a total of 3 symptomatic and 26 silent events. When comparing the two monitoring periods, 7 patients had longer or more severe ST segment depression whereas 6 other patients presented with more severe VPBs on day 2. Three patients had less ischemia on day 2, one remained stable, and 13 had no ischemia throughout the study. Silent ischemia was significantly more prolonged (C.Dur.Sil 316 v 152 sec, P < 0.05) and more intense (C. Area Sil 8 v 3.8 mm.min, P < 0.05) on day 2. Moreover, on top of a normal circadian distribution of ischemic events in the morning and in the evening, 40% of events were related to the donation or to a trip to the hospital. No preoperative characteristic helped to detect patients at risk.(ABSTRACT TRUNCATED AT 250 WORDS)

The SANGUIS Study in Belgium: an overview of methods and results. Safe and good use of blood in surgery.

SANGUIS was multicentric European study involving more than 7,000 patients in 43 teaching hospitals during a one year period. The goal of the study was to describe current transfusion practice for elective surgery in adult. The present paper summarizes the data collected on the 1,193 patients enrolled in Belgium. It also introduces the final report of the SANGUIS study in Belgium, which will be published as a special issue of the Acta Chirurgica Belgica.

Bedside transfusion errors. A prospective survey by the Belgium SAnGUIS Group.

The true incidence of bedside transfusion errors, i.e. those happening when blood products have left the blood bank, is underestimated because published figures rely on reporting of clinically relevant events or on indirect methods. The SAnGUIS project assessing blood practice in a prospective and randomized fashion for 6 elective surgical procedures gave the opportunity to trace all transfused units and to identify steps at risk during blood delivery in surgery. We considered transfusion of a wrong unit as a major error and poor execution or documentation as a recording error. Over 15 months, 808 patients out of 1,448 were transfused with 3,485 units. A total of 165 errors were found after blood products had left the blood banks. Seven were misidentifications (0.74% of patients, 0.2% of units). Eight other major errors occurred in 4 (0.5%) patients. Major errors occurred during nonemergency situations, in wards or intensive care units. The remaining ('recording') 150 errors consisted of misrecordings (61), mislabellings (6), or failures to document transfusions in the medical records (83). All errors were uneventful except one misidentification which induced a transient, yet unreported, reaction. The 'descending' inquiry method used for this study showed that most errors pass unnoticed and are therefore not reported. Measurement of error rates may constitute an important quality indicator. Retrospective information of this survey to the concerned staff people provided an impetus to take adequate measures to reduce these bedside errors.

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.

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.

Median nerve somatosensory evoked potentials in profound hypothermia for ascending aorta repair.

Median nerve somatosensory evoked potentials (SEPs) were recorded in 9 patients undergoing profound hypothermia for surgical repair of the aortic arch. In addition to the known increase in peak latencies, hypothermia gave rise to the appearance of peaks ('P13,' 'N14') inconsistently recognized at normothermia; moreover, profound hypothermia is associated with the disappearance of cortical activities around 20 degrees, of subcortical waves at lower temperatures. The practical implications of the results are 3-fold: firstly, they suggest that the 'P13' and P14 should both be intracranially generated, at a pre- and postsynaptic level with respect to the cuneate nucleus, respectively; secondly, they show that some discrepancies between previous papers dealing with SEPs and hypothermia can be explained by differences in the choice of the reference; thirdly, they bring some suggestions on a better use of SEPs to monitor patients undergoing aortic arch surgery.

A novel preservation medium protecting prostacyclin production and endothelial integrity of the human saphenous vein graft.

Patency rates of coronary artery saphenous vein bypass grafts can be as low as 50% in the first year after surgery. Of these occlusions, 70% can be attributed to mural thrombus formation. Improvements in surgical handling techniques and in preservation media have improved patency rates, as has the introduction of perioperative antiplatelet therapy. The authors describe a novel preservation medium consisting of heparinized blood from the patient, papaverine and dipyridamole. This medium enhances prostacyclin production and maintains endothelial integrity in preserved saphenous vein segments.

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.

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.