PubMed Health⌕ Search

Biomedical subjects

P Mair

Publications and source records attributed to P Mair.

At least 19 recordsLinked to original sources
PubMed2006

[Anaesthesia for cardiac catheterization in children].

Cardiac catheterization in children with congenital heart disease or in adults with completely or partially corrected cardiac defects, is a growing field of activity for anaesthesiologists. This requires not only the willingness for interdisciplinary co-operation, but also detailed knowledge about the pathophysiology of congenital heart diseases. In interventional paediatric cardiology significant innovations have occurred during recent years including stenting of a patent ductus arteriosus and of peripheral pulmonary artery stenosis. Furthermore, radiofrequency catheter ablation for recurrent tachyarrhythmia, or resynchronisation therapy with biventricular pacing in the setting of congestive heart failure, or implantation of cardioverter defibrillators are increasingly being employed which require anaesthesia support.

Anesthesia↗
PubMed2006

Technical challenges in totally endoscopic robotic coronary artery bypass grafting.

OBJECTIVE: Robotic technology is a prerequisite for performance of totally endoscopic coronary artery bypass grafting. During the implementation phase of totally endoscopic coronary artery bypass, surgeon-related technical difficulties might be encountered. It was the aim of this study to assess the incidence of these challenges, to find risk factors, and to describe clinical results associated with technical errors. METHODS: From October 2001 through October 2004, 40 patients received robotically assisted totally endoscopic left internal thoracic artery grafts to the left anterior descending coronary artery system with the da Vinci telemanipulation device. All patients underwent remote access cardiopulmonary bypass perfusion through groin access, and all anastomoses were performed on the arrested heart. RESULTS: Undesirable technical events of various grades occurred in 20 (50%) of 40 patients: bleeding from a port hole in 3 (8%), left internal thoracic artery damage in 3 (8%), epicardial lesion in 3 (8%), remote access perfusion problems in 9 (23%), bleeding from the anastomosis in 4 (10%), and anastomotic stenosis in 2 (5%). There was no hospital mortality. The following differences were noted between patients without technical difficulties (group 1) and those in whom problems occurred (group 2): total operative time of 314 minutes (260-540 minutes) versus 418 minutes (270-690 minutes; P = .007), ventilation time of 6 hours (0-26 hours) versus 14 hours (0-278 hours; P = .004), intensive care unit stay of 20 hours (11-70 hours) versus 44 hours (16-336 hours; P=.183), hospital stay of 7 days (4-13 days) versus 8 days (5-21 days; P = .038), and cumulative freedom from angina at 36 months of 93% versus 100% (P = .317). CONCLUSION: We conclude that technical difficulties during totally endoscopic coronary artery bypass grafting translate into markedly increased operative time, moderately prolonged postoperative ventilation time, and slightly increased hospital stay. Short-term survival and freedom from angina, however, do not seem to be compromised.

Adult↗
PubMed2003

Cardiopulmonary resuscitation after near drowning and hypothermia: restoration of spontaneous circulation after vasopressin.

Recent animal data have challenged the common clinical practice to avoid vasopressor drugs during hypothermic cardiopulmonary resuscitation (CPR) when core temperature is below 30 degrees C. In this report, we describe the case of a 19-year-old-female patient with prolonged, hypothermic, out-of-hospital cardiopulmonary arrest after near drowning (core temperature, 27 degrees C) in whom cardiocirculatory arrest persisted despite 2 mg of intravenous epinephrine; but, immediate return of spontaneous circulation occurred after a single dose (40 IU) of intravenous vasopressin. The patient was subsequently admitted to a hospital with stable haemodynamics, and was successfully rewarmed with convective rewarming, but died of multiorgan failure 15 h later. To the best of our knowledge, this is the first report about the use of vasopressin during hypothermic CPR in humans. This case report adds to the growing evidence that vasopressors may be useful to restore spontaneous circulation in hypothermic cardiac arrest patients prior to rewarming, thus avoiding prolonged mechanical CPR efforts, or usage of extracorporeal circulation. It may also support previous experience that the combination of both epinephrine and vasopressin may be necessary to achieve the vasopressor response needed for restoration of spontaneous circulation, especially after asphyxial cardiac arrest or during prolonged CPR efforts.

Adult↗
PubMed2003

Neither vasopressin nor amiodarone improve CPR outcome in an animal model of hypothermic cardiac arrest.

BACKGROUND: Aim of this experimental animal study was to investigate the influence of vasopressin and amiodarone on cardiopulmonary resuscitation (CPR) outcome in a pig model of hypothermic cardiac arrest. METHODS: After surface cooling to a core temperature of 26 degrees C, ventricular fibrillation was induced in 14 12-16-week-old domestic pigs. After 15 min of untreated cardiac arrest, a manual closed chest CPR was started and pigs were randomly assigned to two treatment groups: Group 1 pigs (n = 7) received vasopressin 0.4 U kg-1 as initial drug therapy, followed by a combination vasopressin (0.4 U kg-1) and amiodarone (4 mg kg-1) as subsequent drug therapy. Subsequent drug therapy was administered in animals without permanent restoration of spontaneous circulation after a first series of electrical countershocks 10 min after drug administration. Group 2 pigs (n = 7) received saline placebo as initial drug therapy and saline placebo and amiodarone (4 mg kg-1) as subsequent drug therapy. RESULTS: Vasopressin significantly increased coronary perfusion pressure and defibrillation success (successful defibrillation in five of seven Group 1 vs. none of seven Group 2 pigs, P = 0.02). Due to refibrillation within 30-150 s, the 60-min survival rate was not improved by vasopressin. Subsequent drug therapy with amiodarone had no further effect on defibrillation success or the refibrillation rate. CONCLUSIONS: Data from this experimental animal model suggest that vasopressin and amiodarone may not be beneficial for treatment of ventricular fibrillation associated with severe hypothermia when concomitant measures at core rewarming are not applied.

Amiodarone↗
PubMed2001

Effects of epinephrine in a pig model of hypothermic cardiac arrest and closed-chest cardiopulmonary resuscitation combined with active rewarming.

OBJECTIVE: The aim of the current study was to assess the effects of epinephrine in a pig model of hypothermic cardiac arrest followed by closed-chest cardiopulmonary resuscitation combined with active rewarming, simulating the clinical management of an arrested hypothermic patient in a hospital without cardiopulmonary bypass facilities. DESIGN: Prospective, randomized animal study. SETTING: University research laboratory. SUBJECTS: Twelve 12- to 16-week-old domestic pigs. INTERVENTIONS: Pigs were surface cooled to a body core temperature of 28 degrees C. After 4 min of untreated cardiac arrest, manual closed-chest CPR and thoracic lavage with 40 degrees C warmed fluid were started. After 3 min of external chest compression animals were randomly assigned to receive epinephrine (45, 45 and 200 microg/kg) or saline placebo in 5-min intervals. MEASUREMENTS AND MAIN RESULTS: Coronary perfusion pressure was about 15 mmHg in placebo group pigs. Coronary perfusion pressure was significantly higher after epinephrine, but restoration of spontaneous circulation was not more frequent (one of six epinephrine versus three of six saline placebo pigs, P=0.34). After 45 microg/kg epinephrine the arterial PO(2) was significantly lower when compared to the saline placebo. The third 200 microg/kg epinephrine dose resulted in a significantly enhanced mixed venous hypercarbic acidosis. CONCLUSIONS: After a short 4-min period of hypothermic cardiac arrest, epinephrine may not be necessary to maintain coronary perfusion pressure around the threshold usually correlating with successful defibrillation, even during prolonged closed-chest CPR combined with active rewarming. The enhanced mixed venous hypercarbic acidosis in epinephrine-treated animals may support the argument against repeated or high dose epinephrine administration during hypothermic CPR.

Analysis of Variance↗
PubMed2001

Orthotopic liver transplantation in a patient with severe portopulmonary hypertension.

Liver transplantation in patients with severe portopulmonary hypertension (PPH) has been associated with mortality rates in the range of 70% to 80%. Preoperative long-term epoprostenol therapy reverses pulmonary hypertension and may be a valuable possibility to reduce mortality in patients with severe PPH undergoing orthotopic liver transplantation. We want to report a patient with severe PPH, who was treated with intravenous epoprostenol for an 8-month period, after which pulmonary vascular resistance had decreased from 12 to 3 Wood units. Nevertheless, the patient developed intractable perioperative right heart failure necessitating transient mechanical circulatory support. The patient was weaned from mechanical circulatory support, but died from another episode of acute right heart failure after 28 days. Complicated liver transplantation associated with major cardiovascular stress is obviously not tolerated in patients with severe portopulmonary hypertension even after preoperative long-term epoprostenol therapy.

Adult↗
PubMed2001

Liver transplantation without venovenous bypass: morbidity and mortality in patients with greater than 50% reduction in cardiac output after vena cava clamping.

OBJECTIVE: To investigate whether a decrease in cardiac output of >or=50% after vena cava clamping is associated with an increase in perioperative morbidity or mortality in patients undergoing orthotopic liver transplantation without venovenous bypass. DESIGN: Retrospective, clinical study. PARTICIPANTS: Patients undergoing elective orthotopic liver transplantation without venovenous bypass (n = 172). INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: In 82 patients (group 1), the decrease in cardiac output after vena cava clamping was >or=50%; in 90 patients (group 2), the decrease was <50%. Hemodynamics during surgery and perioperative morbidity and mortality were compared between group 1 and group 2 patients. Mean arterial pressure during the anhepatic phase was not significantly different between groups, but cardiac output and mixed venous oxygen saturation were significantly lower in group 1 patients. Perioperative mortality, need for postoperative renal replacement therapy, postoperative serum creatinine levels, and graft function were not different between groups. CONCLUSION: A >50% reduction in cardiac output after vena cava clamping is not associated with an increase in perioperative morbidity and mortality when compared with patients with a less pronounced reduction in cardiac output. These results question the common practice of basing the indication for venovenous bypass during the anhepatic phase on a reduction in cardiac output of >50% after a trial of vena cava clamping.

Cardiac Output↗
PubMed2000

Cardiopulmonary resuscitation during severe hypothermia in pigs: does epinephrine or vasopressin increase coronary perfusion pressure?

UNLABELLED: The American Heart Association does not recommend epinephrine for management of hypothermic cardiac arrest if body core temperature is below 30 degrees C. Furthermore, the effects of vasopressin administration during hypothermic cardiac arrest are totally unknown. This study was designed to assess the effects of vasopressin and epinephrine on coronary perfusion pressure in a porcine model during hypothermic cardiac arrest cardiopulmonary resuscitation (CPR). Pigs were surface-cooled until their body core temperature was 26 degrees C. After 30 min of untreated cardiac arrest, followed by 3 min of basic life support CPR, 15 animals were randomly assigned to receive, at 5-min intervals, either vasopressin (0.4, 0.4, and 0.8 U/kg; n = 5), epinephrine (45, 45, and 200 microg/kg; n = 5), or saline placebo (n = 5). Compared with epinephrine, mean +/- SEM coronary perfusion pressure was significantly higher (P < 0.05) 90 s and 5 min after the first (35+/-4 vs 22+/-3 mm Hg and 37+/-2 vs 16+/-2 mm Hg) and the second vasopressin administration (40+/-5 vs 26+/-5 mm Hg and 36+/-5 vs 18+/-2 mm Hg, respectively). After the third drug administration, coronary perfusion pressure in the epinephrine group increased dramatically and was comparable to vasopressin. In the saline placebo group, coronary perfusion pressure was significantly lower (P < 0.05) than in the vasopressin and epinephrine groups. Six animals treated with epinephrine or vasopressin had transient return of spontaneous circulation, whereas all placebo animals died (P < 0.05). During CPR in severe hypothermia, administration of both vasopressin and epinephrine resulted in significant increases in coronary perfusion pressure when compared with placebo. IMPLICATIONS: Our study was designed to assess the effects of vasopressin and epinephrine in a porcine model simulating cardiac arrest during severe hypothermia. This study demonstrates that the administration of both emergency drugs results in an increased perfusion pressure in the heart.

Animals↗
PubMed2000

Intraosseous blood gases during hypothermia: correlation with arterial, mixed venous, and sagittal sinus blood.

OBJECTIVE: Especially in pediatric patients with severe hypothermia, intraosseous access may be more readily available than intravascular access during an early phase of treatment and therefore, may be helpful to optimize management. The purpose of this study was to determine whether intraosseous blood gases are comparable with arterial, mixed venous, and sagittal sinus blood gases during different degrees of hypothermia. DESIGN: Prospective, descriptive laboratory investigation using a porcine model. SETTING: University hospital laboratory. SUBJECTS: Twelve anesthetized, 12- to 16-wk-old domestic pigs weighing 30-35 kg. INTERVENTIONS: Volume-controlled ventilated animals were instrumented with arterial, pulmonary artery, sagittal sinus, and 16-gauge intraosseous catheters. Blood samples were obtained from each site every 15 mins during surface cooling with crushed ice until mean +/- SEM core temperature decreased from 38.5+/-0.1 degrees C [101.3+/-0.2 degrees F] to 27+/-0.5 degrees C [80.5+/-0.9 degrees F] over 2 hrs. MEASUREMENTS AND MAIN RESULTS: Intraindividual correlation of Pco2 and pH values were determined as the difference (delta) between intraosseous and reference blood samples. With hypothermia, absolute values of Pco2 decreased and pH increased in samples from all sites. At 27 degrees C, intraosseous--arterial delta P(CO2) and delta pH (mean +/- 95% confidence intervals) were 2.6+/-10.6 torr [0.35+/-1.4 kPa] and -0.11+/-0.07 units; intraosseous - mixed venous were 0.4+/-12.2 torr [0.05+/-1.6 kPa] and -0.06+/-0.08 units; and intraosseous - sagittal sinus were -7.3+/-16 torr [-0.97+/-2.1 kPa] and 0.001+/-0.14 units, respectively. Intraosseous Pco2 was not comparable to end-tidal values (deltaP(CO2) 17.4+/-14.6 torr [2.3+/-1.9 kPa]), and intraosseous lactate did not correlate with arterial, mixed venous, or sagittal sinus values. CONCLUSIONS: During hypothermia, intraosseous P(CO2) values were predictable for mixed venous Pco2 and arterial P(CO2). Intraosseous pH values also correlated with mixed venous and sagittal sinus blood samples. Accordingly, interpretation of blood gas values obtained from bone marrow aspirates may be helpful to adjust ventilation and optimize fluid and drug therapy during the early treatment of patients with severe hypothermia.

Animals↗
PubMed2000

Vasopressin-mediated adrenocorticotropin release increases plasma cortisol concentrations during cardiopulmonary resuscitation.

OBJECTIVE: Vasopressin is a possible stimulus for both adrenocorticotropin (ACTH) and endothelin-1 release. The aim of this study was to compare plasma concentrations of ACTH, cortisol, and endothelin-1 after epinephrine or vasopressin administration in an experimental animal model of cardiopulmonary resuscitation (CPR). DESIGN: Prospective, randomized, controlled animal study. SETTING: A university research laboratory. SUBJECTS: Fourteen 12- to 14-wk-old domestic pigs. INTERVENTIONS: After 4 mins of cardiac arrest and 3 mins of external chest compression, the pigs were randomly assigned to receive either 0.045 mg/kg epinephrine (n = 7) or 0.4 units/kg vasopressin (n = 7). At 5 mins after drug administration, defibrillation was attempted. MEASUREMENTS AND MAIN RESULTS: Coronary perfusion pressure, ACTH, cortisol, and endothelin-1 were measured before cardiocirculatory arrest, during CPR before drug administration, and at 90 secs and 5 mins after drug administration. Coronary perfusion pressure was comparable between groups. All seven animals in the vasopressin group survived, but only one pig in the epinephrine group survived (p = .005). ACTH and cortisol concentrations remained unchanged in epinephrine-treated animals, but increased significantly after vasopressin administration and were significantly higher than in epinephrine-treated animals 5 mins after drug administration. Endothelin-1 concentrations remained unchanged during the study period and were comparable between both groups. CONCLUSIONS: Vasopressin is a potent stimulus for ACTH secretion, but does not trigger endothelin-1 release from vascular cells during cardiac arrest and CPR. The increased plasma cortisol concentrations caused by the enhanced ACTH release after vasopressin may be one factor contributing to the improved outcome repeatedly observed with vasopressin in animal models of CPR.

Adrenocorticotropic Hormone↗
PubMed1999

Isolated right ventricular assist for postcardiotomy myocardial infarction.

Due to myocardial infarction, profound postcardiotomy right heart failure developed in a 57-year-old man after implantation of an aortic homograft for infective aortic valve endocarditis. Despite maximum medical therapy and intraaortic balloon counterpulsation, signs of endorgan injury developed, and therefore a Thoratec (Pleasanton, CA) right ventricular assist device was implanted. After 17 days of support, myocardial and endorgan function had recovered and the fully mobilized patient was successfully weaned from support and discharged from the hospital.

Cardiac Surgical Procedures↗
PubMed1999

Increased frequency of thorax injuries with ACD-CPR.

A prospective, randomised out-of-hospital study in a two-tiered system with active compression-decompression (ACD) cardiopulmonary resuscitation (CPR) versus standard (STD) CPR in patients following non-traumatic cardiac arrest was planned to test the hypothesis that ACD-CPR by the first tier may increase the occurrence of ventricular fibrillation as compared with STD-CPR. Furthermore, in a later phase of the study, sternal and rib fractures induced by both CPR methods were determined by extensive autopsy. After enrolling 90 patients the study was terminated because of a high frequency of chest injuries found at autopsy. Forty-two patients received STD-CPR from the first tier and ACD-CPR from the second tier. Thirty-three patients received ACD-CPR only by the first and the second tier, while 15 patients received STD-CPR only from the first and second tiers. In order to obtain a sufficiently large control group for autopsy findings after STD-CPR, STD-CPR was performed in an additional 33 patients within a second period of 4 months. There was no improvement in the number of patients found in ventricular fibrillation after ACD-CPR as compared to STD-CPR performed by the first tier. In patients undergoing autopsy (n = 35) there were significantly more sternal fractures with ACD-CPR versus STD-CPR (14/15 vs. 6/20; P <0.005) and rib fractures (13/15 vs. 11/20; P < 0.05) In conclusion, ACD-CPR appears to cause more CPR-related injuries than does standard CPR, but as a result of a number of limitations on this study, this fact cannot be proven beyond doubt.

Aged↗
PubMed1999

Forced air surface rewarming in patients with severe accidental hypothermia.

Methods of rewarming patients with severe accidental hypothermia remain controversial. This paper reports our experience with the use of forced air rewarming in patients with severe accidental hypothermia and a body core temperature below 30 degrees C. Fifteen hypothermic patients (body core temperature 24-30 degrees C) were successfully treated with forced air rewarming to a body core temperature above 35 degrees C (mean rewarming rate 1.7 degrees C/h, range from 0.7 to 3.4 degrees C/h). An afterdrop phenomenon was not observed in any of the patients. Nine hypothermic patients (group 1) had no prehospital cardiac arrest, all nine were long-term survivors and made a full recovery. Six patients (group 2) had prehospital cardio circulatory arrest with restoration of spontaneous circulation. None of the group 2 patients survived long-term. Group 1 and group 2 patients did not differ in core temperature (26.6+/-1.6 degrees C group 1 and 27.0+/-1.8 degrees C group 2). Group 2 patients needed catecholamine support during rewarming more frequently (83 versus 22%) and had higher lactate levels and lower pH values at all points of observation. In conclusion our preliminary data indicate that forced air rewarming is an efficient and safe method of managing patients with severe accidental hypothermia. The poor outcome of patients with a history of prehospital cardiopulmonary resuscitation is probably due to irreversible ischaemic brain damage in primarily asphyxiated avalanche and near-drowning victims, rather than the consequence of the rewarming method used.

Adolescent↗
PubMed1999

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. METHODS: Forty patients undergoing elective aortocoronary bypass surgery were included into this prospective, randomized clinical study, 20 in the leucocyte depletion (LG-6 group, leucocyte-specific arterial line filter) and 20 in the control group (AV-6 group, standard arterial line filter). White cell count, differential white cell count, plasma elastase concentration, plasma malondialdehyde concentration and C-reactive protein were determined before, twice during and immediately after cardiopulmonary bypass, at the end of surgery and 6 and 20 h thereafter. RESULTS: White cell count, differential white cell count, malondialdehyde and C-reactive protein were not significantly different between LG-6 and control patients. Plasma elastase concentrations were significantly (P < or = 0.03) higher during and immediately after extracorporeal circulation in LG-6 group patients. Need for inotropic support, arterial pO2 after extracorporeal circulation and perioperative CK MB mass and troponin I release were not different between the two groups of patients. CONCLUSION: The use of a leucocyte depleting arterial line filter is associated with an increased release of the proteolytic enzyme elastase, but does not reliably and consistently achieve effective leucocyte depletion during clinical perfusion. In contrast to previous studies, we could not demonstrate any significant difference in postbypass pulmonary or myocardial function between patients perfused with the leucocyte-specific arterial line filter and control patients. Our data do not support the routine use of a leucocyte depleting arterial line filter during clinical perfusion in patients undergoing elective aortocoronary bypass surgery.

Aged↗