Doris Balogh

Prognostic markers in patients with severe accidental hypothermia and cardiocirculatory arrest

The aim of this retrospective study was to investigate whether plasma potassium, pH and activated clotting time (ACT), obtained from a central venous blood sample immediately after admission to hospital, could predict outcome in patients with severe accidental hypothermia and cardiocirculatory arrest. Twenty-two patients rewarmed with cardiopulmonary bypass were studied retrospectively (12 patients after avalanche accidents, seven patients after cold water submersion and three patients after prolonged exposure to cold). In 12 patients stable spontaneous circulation could not be restored. In 10 patients stable spontaneous circulation could be restored. Two of these 10 patients survived long-term. Plasma potassium, central venous pH and ACT were clinically useful prognostic markers in hypothermic arrest victims after avalanche accidents: a plasma potassium value exceeding 9 mmol/l, a pH equal to or less than 6.50 or an ACT exceeding 400 s was seen in patients in whom spontaneous circulation could not be restored. Plasma potassium, central venous pH and ACT were of only limited prognostic value in hypothermic arrest victims following cold water submersion or prolonged exposure to cold. In hypothermic arrest victims after cold water submersion a central venous pH as low as 6.51 on admission did not exclude long-term survival. Moderate and severe hyperkalemia in arrest victims after prolonged exposure to cold need not necessarily indicate postmortem autolysis. A decision to continue or terminate resuscitation cannot be based on laboratory parameters. Nevertheless, our data suggest that plasma potassium, central venous pH and ACT on admission can be used to identify hypothermic arrest victims in whom death preceded cooling. If several hypothermic arrest victims are admitted simultaneously after avalanche accidents, these 3 parameters can help not to waste limited cardiopulmonary bypass facilities for patients with no hope of survival.

Percutaneous venoarterial extracorporeal membrane oxygenation for emergency mechanical circulatory support

In this retrospective study we report our initial experience with percutaneous venoarterial extracorporeal membrane oxygenation in the emergency treatment of intractable cardiogenic shock or pulseless electrical activity. Between January 1994 and July 1995, percutaneous venoarterial extracorporeal membrane oxygenation was attempted in seven patients (pulseless electrical activity, five patients; cardiogenic shock, two patients). In two of the seven patients, efforts at arterial cannulation resulted in cannula perforation at the level of the iliac artery. In the remaining five patients, percutaneous venoarterial extracorporeal membrane oxygenation could be established and was maintained for 3-84 h. Major bleeding remained a common complication during extracorporeal membrane oxygenation despite the use of heparin-coated bypass circuits and was responsible for death during extracorporeal membrane oxygenation in one patient. The remaining four patients could be weaned from mechanical circulatory support within 24 h, two after surgical interventions (resection of right atrial tumor, heart transplantation), one after thrombolytic therapy. In one patient, cardiac function recovered spontaneously after 6 h on venoarterial extracorporeal membrane oxygenation. Three patients were discharged from hospital, two of them made a full recovery, one sustained severe hypoxic brain injury. A few patients with intractable cardiogenic shock or pulseless electrical activity can be resuscitated with the help of emergency percutaneous venoarterial extracorporeal membrane oxygenation. Emergency venoarterial extracorporeal membrane oxygenation is associated with a high rate of complications and its use should therefore be limited to selected patients with a rapidly correctable underlying cardiopulmonary pathology (anatomic, metabolic or hypothermic) who do not respond to conventional advanced cardiac life support.

Augmented release of brain natriuretic peptide during reperfusion of the human heart after cardioplegic cardiac arrest

The aim of the study was to investigate the release of natriuretic peptides during myocardial ischaemia and reperfusion associated with cardioplegic cardiac arrest. Brain natriuretic peptide (BNP) and atrial natriuretic peptide (ANP) concentrations were measured in paired arterial, central venous and coronary sinus blood samples in 19 patients undergoing elective coronary artery bypass grafting before aortic crossclamping and 1, 5, 10 and 20 min after aortic declamping. Peak myocardial BNP release after aortic declamping was significantly higher than baseline values before aortic crossclamping. Both peak and cumulative BNP release during reperfusion correlated significantly with the severity of ischaemia, as assessed by myocardial lactate production. In 3 patients with perioperative myocardial ischaemia, cumulative and peak myocardial BNP release after aortic unclamping was markedly higher than in the remaining 16 uneventful patients. Myocardial ANP release during reperfusion was not significantly different from baseline values before aortic crossclamping. In conclusion, our data demonstrate a significantly enhanced myocardial BNP release early during reperfusion of the human heart after global ischaemia associated with cardioplegic cardiac arrest.

Effects of a leucocyte depleting arterial line filter on perioperative proteolytic enzyme and oxygen free radical release in patients undergoing aortocoronary bypass surgery

Background: Proteolytic enzymes and oxygen free radicals released from activated leucocytes contribute significantly to the organ dysfunction associated with cardiopulmonary bypass. Leucocyte depletion during extracorporeal circulation should reduce the release of these toxic compounds and thereby improve postbypass myocardial and pulmonary function. Recently, a leucocyte‐specific arterial line filter to achieve leucocyte depletion during clinical perfusion has become commercially available. The aim of this study, therefore, was to evaluate the influence of the leucocyte depleting arterial line filter on proteolytic enzyme release, oxygen free radical release and postbypass pulmonary and myocardial function in patients undergoing bypass surgery.

Aortic valve replacement in the conscious patient under regional anesthesia without endotracheal intubation

See related articles on pages 1204, 1394, and 1401. Minimally invasive operative procedures are of increasing interest to surgeons, including cardiac surgeons. Aside from the obvious advantage of reducing the surgical trauma, implementation of regional anesthesia is currently under investigation in heart surgery. Our aim was to determine the feasibility of using regional anesthesia without endotracheal intubation in aortic valve replacement with extracorporeal circulation in the conscious patient.

CASE 5--1997 Successful Resuscitation of a Patient With Severe Accidental Hypothermia and Prolonged Cardiocirculatory Arrest Using Cardiopulmonary Bypass

Case Presentation A poorly equipped 54-year-old man without climbing experience crossed a heavily crevassed glacier in the Austrian Alps. After a few minutes walk, he fell into a narrow crevasse about 4 meters deep. A rescue team was immediately summoned and arrived about 50 minutes later. The victim in the crevasse was conscious when the rescue team arrived but had slipped farther down the crevasse, by melting the ice around him with his body temperature. In the following hour, several efforts to reach the victim and to tie a rope around his body failed because the crevasse was too narrow. Meanwhile, the victim in the crevasse had become unresponsive, and occasional sighing remained the only visible sign of life. Finally, a very small member of the rescue team managed to fix a rope around the man, and the victim was removed from the crevasse within a few minutes. Rough handling of the patient during rescue and postural changes could not be totally avoided. Meanwhile, an emergency physician had arrived by helicopter. He immediately evaluated the patient removed from the crevasse. The patient was in deep coma, had no spontaneous breathing, no palpable pulses, and fixed, dilated, pupils. Electrocardiogram (ECG) demonstrated ventricular fibrillation. The patient was endotracheally intubated, artificially ventilated, and external chest compression was started. Tympanic temperature was measured and demonstrated severe accidental hypothermia with a body core temperature of 23°C. Therefore, the emergency physician decided to transport the patient immediately to this center by helicopter for rewarming with extracorporeal circulation (ECC). No medication was given on the scene or during air transport, and there were no attempts at defibrillation at the scene. After a 20-minute flight with ongoing cardiopulmonary

Graft replacement of post-traumatic thoracic aortic aneurysm: results without bypass or shunting.

From 1986 to 1991 13 cases of post-traumatic thoracic aneurysm were treated at our department. All patients had apparent thoracic injury at the time of trauma, and their mean age was 35 years. The mean time between trauma and operation was 3 years and six patients were asymptomatic. In all patients the diagnosis was made by computed tomography and angiography and all post-traumatic thoracic aneurysms were located at the aortic isthmus. No spinal cord protection by bypass or shunting was used during surgery and the clamp-and-repair method with a mean clamping time of 38 min was used in all 13 patients. No renal or neurological complications were observed postoperatively and there were no hospital deaths. The data of 202 patients who had been operated upon for post-traumatic thoracic aneurysms since 1981 have been reviewed with regard to the relationship between spinal cord protection and the incidence of postoperative paraplegia. Different methods of spinal cord protection were used in 121 patients resulting in paraplegia rate of 1.6%. In 81 patients the clamp-and-repair method was used and no case of paraplegia was observed in this group.

Reperfusion after cardioplegic cardiac arrest--effects on intracoronary leucocyte elastase release and oxygen free radical mediated lipid peroxidation.

In experimental animal models reperfusion of ischaemic myocardium causes sequestration of leucocytes within the coronary circulation. Leucocytes contribute to postischaemic myocardial injury by releasing proteolytic enzymes and by generating oxygen free radicals. The aim of this study was to investigate whether leucocytes also contribute to myocardial injury following ischaemia and reperfusion associated with cardioplegic cardiac arrest. Therefore, we studied the release of the proteolytic enzyme elastase and oxygen free radical initiated myocardial lipid peroxidation in coronary sinus blood during reperfusion after cardioplegic cardiac arrest. The elastase‐alpha‐1‐proteinase inhibitor complex and malondialdehyde (a byproduct of myocardial lipid peroxidation) were measured in arterial, central venous and coronary sinus blood samples in 19 patients undergoing elective coronary artery bypass grafting before aortic crossclamping and 1,5, 10 and 20 min after aortic declamping. Malondialdehyde concentrations did not increase significantly during the study period, whereas elastase concentrations showed a significant increase during cardiopulmonary bypass in arterial, central venous as well as coronary sinus blood. Neither elastase nor malondialhyde concentrations in coronary sinus blood differed significantly from arterial or central venous blood at any time point measured. Our data demonstrated increased elastase concentrations during cardiopulmonary bypass, but we did not find enhanced intracoronary elastase release or myocardial lipid peroxidation. Our data suggest that patients are sufficiently protected from leucocyte mediated ischaemia reperfusion injury during uncomplicated coronary artery bypass grafting with cardioplegic arrest.

Intraoperative Kalorimetrie bei Aortengabelrekonstruktion

ZusammenfassungVeränderungen des Stoffwechsels sollten mit der indirekten Kalorimetrie unter Routinebedingungen bei Aortengabelrekonstruktionen untersucht werden. Elf männliche Patienten wurden in totaler intravenöser Anästhesie (TIVA) mit dem Servoventilator 900 D ohne Lachgase mit FiO2 0,5 beatmet. Kalorimetriert wurde mit einem Deltatrac® (Datex). Zur Auswertung wurden folgende Meßpunkte herangezogen: 5 min nach Intubation, 5 min vor Aorten-Klemme = Referenzwert, bei Klemmen; 5, 10, 15 min nach Öffnen; 1, 5, 10 min nach Öffnen und bei Operationsende. Zur statistischen Berechnung wurde der Student-t-Test für gepaarte Werte verwendet. Die Aortenklemmung führt zu einem Abfall von V˙O2 (90% des Ausgangswertes) und V˙CO2 (75% des Ausgangswertes) (Abb. 1, 2, 3). Das Öffnen der Klemme führt bei jedem Bein zu einem signifikanten Anstieg von V˙O2 (118%); Die CO2-Produktion steigt etwas langsamer, ist jedoch für das 1. Bein ebenfalls signifikant (90%). Auffallend ist eine kontinuierliche Abnahme des respiratorischen Quotienten von (MP1) 0,98±0,11 bis zu 0,75±0,06 bei OP-Ende. Das dichte Nicht-Rückatmungssystem des Servo-Ventilators 900 D ermöglicht mit dem Deltatrac eine zuverläßliche, rasche und nicht invasive Messung von V˙O2 und V˙CO2, wenn kein Lachgas verwendet wird und FiO2<0,6 ist. Der Abfall des RQ von Narkose-Beginn bis OP-Ende uß als Zeichen einer vermehrten Fettverbrennung angesehen werden.AbstractOxygen uptake (V˙O2) and carbon dioxide elimination (V˙CO2) can be measured with an indirect calorimeter; this method is well established in routine monitoring of ICU patients to evaluate metabolic state as a reflection of stress. In various experimental studies it was demonstrated that anaesthetics can influence whole-body metabolism. The purpose of this study was to examine whether indirect calorimetry can be used intraoperatively during routine anaesthesia and whether presumable changes in metabolism can be detected immediately. Abdominal aortic cross-clamping changes circulation, nutritional supply of the lower extremities and thus V˙O2 and V˙CO2. We therefore used this operation for our study. Method. Eleven patients, mean age 64 years, undergoing reconstruction of the aortic bifurcation, were studied. After premedication with piritramid and atropine, total intravenous anaesthesia (TIVA) was performed with fentanyl and midazolam after an induction with thiopental. Patients were ventilated with a Servo-Ventilator 900 D and a constant FiO2 of 0.5, without N2O. Routine monitoring consisted of ECG, pulsoximetry, CVP and continuous AP. V˙O2 and V˙CO2 were measured with a Deltatrac® (Datex), and data were registered every minute. For statistical evaluation we used a Wilcoxon-Ranksum test for matched pairs, p<0.05 was considered significant. Data from specific time (5 min after intubation, 5 min before clamping; 5, 10 and 15 min after clamping, before declamping and 5 and 10 min after declamping and at the end of surgery) were calculated. In addition to absolute values, we compared the measured V˙O2 and V˙CO2 to baseline (5 min before clamping=MP2). Results. Mean operating time was 139 min±37; aortic cross-clamping time for the first extremity was 38 min and 55 min for the second. As expected, there was a significant decrease in V˙O2 (90% of baseline) and V˙CO2 (75% of baseline) during aortic cross-clamping. After declamping V˙O2 again rose to 110% of baseline, or to 103% for the second limb. V˙CO2 increased to only 90% and 82%, respectively. At the end of surgery V˙O2 reached baseline, whereas V˙CO2 remains at 83%. The respiratory quotient V˙CO2: V˙O2 was markedly reduced from 0.95±0.156 to 0.73±0.06 during surgery. The Deltatrac® showed every change in V˙O2 without delay; changes in V˙CO2 seem to occur somewhat retarded. Discussion. Aortic cross-clamping leads to a marked decrease in V˙O2 and V˙CO2 reflecting the temporary reduction in whole-body metabolism. Declamping results in a compensatory rise, especially in V˙O2. V˙CO2 seems to increase less after declamping, perhaps due to the CO2 pool of the organism or to a change in metabolism from carbohydrate to mainly fat oxidation.The results of this study demonstrate that indirect calorimetry can easily be performed during anaesthesia and surgery. Preconditions are a non-rebreathing system without airleak, constant FiO2<0.6 and no use of nitrous oxide.

Myoglobin, troponin T and Myosin measurements in the diagnosis of perioperative myocardial infarction in aortocoronary bypass surgery

Introduction: Aim of this study was to investigate the release kinetics of three different marker proteins of myocardial ischaemia (Myoglobin, Troponin T and Myosin) following aortocoronary bypass surgery and elucidate their value in the diagnosis of perioperative myocardial infarction. methods: After institutional approval and informed consent 26 patients scheduled for aortocoronary bypass surgery were investigated. 4 patients (group 1) suffered perioperative myocardial infarction (electocardiographic findings together with elavated CK MB activity measurements for more than 18 hours), 4 patients (group 2) minor perioperative myocardial ischaemia (elevated CK MB measurements for more than 4 but less than 18 hours with or without ST-T segment changes). 18 patients (group 3) had uneventful surgery (CK MB activity measurements ~20 U/I only withhin 4 hours of aortic declamping). CKMB activity, Myoglobin, Troponin T and Myosin were measured before surgery, before cardiopulmonary bypass, after aortic declamping, 1, 2, 3, 4, 8, 12, 16 and 20 hours later and daily thereafter for 7 days. results: Myoglobin concentrations peaked 1 hour after aortic declamping (group 1: mean 949, SD 343 ug/l; group 2: mean 361, SD 97 ug/l, group 3: mean 313, SD 36 ug/l) and again 12 to 24 hours later (group 1: mean 3303, SD 2536 ug/l, group 2: mean 322, SD 109 ug/l, group 3: mean 255, SD 51 ug/l). Peak concentrations differed significantly between patients with perioperative myocardial infarction (group 1) and group 2 (pc 0.05) and group 3 (pe 0.05) patients. Peak concentrations did not differ significantly between patients with minor perioperative myocardial ischaemia (group 2) and group 3 patients. Myoglobin concentrations in general returned to preoperative values withhin 24 hours. In all three groups Troponin T measurements were elevated after aortic declamping, reached peak values withhin 24 hours and stayed that high for 7 days (peak values: group 1: mean 33.7, SD 20.1 ug/l, group 2: mean 2.9, SD 0.9 ug/l, group 3: mean 1.43, SD 0.20 ug/l). Troponin T measurements differed significantly between all three groups (p 21 ug/l for more than 24 hours) and electrocardiographic findings suggestive for myocardial ischaemia (1 patient) or postoperative tachyarrhythmias (2 patients). Myosin measurements did not exceed 300 ug/l before postoperative day 4 (group 1) or postoperative day 5 (group 2 and 3). Myosin measurements remained elevated until postoperative day 7. Myosin measurements did not differ significantly between the three groups. discussian; Myoglobin measurements enable very early diagnosis of perioperative myocardial infarction (1). Myoglobin measurements are only useful in the diagnosis of extended myocardial necrosis and are in general elevated for no more than 24 hours. Troponin T measurements enable early diagnosis of perioperative myocardial necrosis and detect small myocardial infarction as well. Troponin T concentrations stay high in patients with perioperative myocardial infarction for at least one week. Troponin T measurements detect small myocardial necrosis unrecognized by CK MB activity measurements. Myosin measurements do not enable diagnosis of perioperative myocardial infarction before postoperative day four.