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ABSTRACT: Nitric oxide (NO) production by both coronary endothelial cells and cardiomyocytes is thought to play a significant role in myocardial pathophysiology following ischemia/reperfusion (I/R).
In thirteen pigs subjected to 1 hour cardioplegic arrest (CA) on CPB, left ventricular (LV) biopsies were collected prior to CPB (baseline), at 60 min CPA, at 15 and 30 min reperfusion on CPB, and at 120 min post CPB. LV specimens were immunocytochemically stained against phospho-eNOS (Ser1177), phospho-eNOS (Thr495), phosphorylated ERK1/2, and AKT/PKB. Four additional pigs without CA served as controls. Cardiomyocytes were quantitatively investigated using TV densitometry (gray units: U).
After 60 min CA phosphorylation of eNOS (Ser1177) increased significantly and remained elevated until 30 min of reperfusion. In contrast, eNOS (Thr495) phosphorylation remained unchanged during CA and throughout reperfusion. In control animals, eNOS phosphorylation remained unchanged. Akt/PKB activity significantly increased after 60 min CA and decreased thereafter. ERK1/2 activity remained unchanged during ischemia but increased during reperfusion.
ENOS activation during ischemia occurs through phosphorylation at Ser1177 mediated by Akt/PKB. ERK1/2 does not seem to be involved in myocardial eNOS regulation especially not via phosphorylation at eNOS (Thr495).
The Thoracic and Cardiovascular Surgeon 10/2009; 57(7):379-85. · 0.88 Impact Factor
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ABSTRACT: The optimal hematocrit (HCT) value after coronary artery bypass grafting on cardiopulmonary bypass (CPB) has not yet been established. The purpose of our retrospective study was to investigate the association between HCr at the time of entry into the ICU and perioperative Ml rate.
We reviewed the charts of 500 consecutive coronary artery surgery patients with respect to biometric data, operative procedure, aprotinin or tranexamic acid use, perioperative drainage blood loss and transfusion requirements, perioperative Ml, ICU stay and hospital mortality. Perioperative Ml was defined as new Q-wave on ECG and CK-MB 250U/I. Patients were categorized into three groups depending on their HCr value at the time of entry into the ICU: low (HCTcu 27%): medium (HCr,cu 28% to 32%); high(HCTrcu > or =33%).
Age, gender distribution, preoperative LV function, and previous Ml rate were similar between the three groups. Low HCT patients (n -133) received 3.1 +/- 1.0 (Mean + SD) grafts during 55 +/- 19 minutes aortic cross clamp time, 98 +/- 31 minutes on CPB (medium HCT: n = 257; 3.2 +/- 1.0 grafts, 51 +/- 20 min cross clamp time, 93 +/- 30 min CPB; p - 0.45 vs. low HCT; high HCT: n = 110: 3.3 +/- 1:0 grafts; 53 +/- 20 min cross clamp time; 104 +/- 38 min CPB; p = 0.02 vs. medium HCT). The perioperative Ml rate was 3.8% in the low, 4.3% in the medium, and 6.4% in the high-HCr group (p =0.59 ). Intraoperative red blood cell and fresh frozen plasma transfusions were similar between the groups. In the low-HCa group, 53.4% of the patients received aprotinin during the procedure (medium HCa: 65.4%; high HCT: 77.3%; p<0.001). Drainage blood loss during the first 24 hours on ICU was 834 +/- 453 ml in the low, 757 +/- 485 ml in the medium (p -0.44 vs. low), and 640 +/- 353 ml in the high-HCr group (p = 0.003 vs. low). Postoperative red blood cell and fresh frozen plasma transfusions were highest in the low-HCa group(p<0.001). ICU stay was similar between the groups. Hospital mortality was 0.75% in the low, 1.9% in the medium, and 4.5%in the high-HCa group (p = 0.12).
In this retrospective analysis of 500 consecutive coronary artery surgery patients, we did not find any association between perioperative Ml rate and HCr value on entry into the ICU. These results do not support the recent suggestion that low HCT at the time of entry into the ICU protects against perioperative Ml.
The Thoracic and Cardiovascular Surgeon 10/2002; 50(5):259-65. · 0.88 Impact Factor
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ABSTRACT: Air embolism frequently occurs under neurosurgical operations performed in the sitting position. Recently we reported the idea of inserting a re-usable doppler probe into a blind-ending lumen of a central venous catheter (Schregel-Volk-Catheter, SVC). In vitro testing in a circulation model showed a high sensitivity: air bubbles as small as 0.5 microliter were reliably detected at a distance up to 4 cm from the tip of the SVC.
After approval by the local ethics committee pigs were anaesthetised and a cardiopulmonary bypass was connected. During the bypass period a 12 F SVC (Medex Medical, Germany) with one blind-ending lumen was positioned into the proximal vena cava cranialis or vena cava caudalis. An 8 MHz doppler probe (MTB Basler, Suisse) was introduced into the SVC and connected with the doppler device Multi-Dop T (DWL, Germany). Well defined air bubbles (3-6 microliter) were generated by a bubble generator and injected into the right femoral vein or the left vena jugularis interna.
All bubbles were reliably detected by the re-usable doppler probe. Embolic events can be documented, counted and quantified by the Multi-Dop T.
Using SVC's with a blind-ending lumen could improve and simplify the detection of air embolism. We see several advantages (e.g. sensitivity, costs) compared with established methods (precordial doppler, TEE) for detection of air embolism.
Der Anaesthesist 10/2002; 51(9):716-20. · 0.99 Impact Factor
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ABSTRACT: Fragestellung. Venöse Luftembolien treten u. a. bei neurochirurgischen Eingriffen auf. Zur Senkung der Morbidität und Mortalität der venösen
Luftembolie tragen Prävention und Früherkennung bei. Zur Diagnostik von Luftembolien wurde eine in einen Zentralvenenkatheter
(Schregel-Volk-Katheter, SVK) einschiebbare, wiederverwendbare Dopplersonde beschrieben. In-vitro-Untersuchungen konnten die
hohe Sensitivität belegen: Luftembolien bis zu 0,4 μl konnten bis zu 4 cm um die SVK-Spitze herum detektiert werden.
Methodik. Nach Genehmigung durch die Bezirksregierung Köln wurden 6 Schweine (43,2±5,9 kg) anästhesiert, thorakotomiert und parallel
zu einem herzchirurgischen Experiment an eine Herz-Lungen-Maschine angeschlossen. In dieser Phase wurde ein zweilumiger 12-F-SVK
mit einem blind endenden proximalen Lumen (Medex Medical, Deutschland) in die herznahe V. cava cranialis oder caudalis vorgeschoben.
In das blind endende Lumen des SVK wurde eine 8-MHz-Dopplersonde (MTB Basler, Schweiz) eingebracht und mit dem Dopplergerät
Multidop T (DWL, Deutschland) verbunden. Ein elektronisch-gesteuerter Mikrogasblasengenerator erzeugte einzelne Luftembolien
mit einem Volumen von 3–6 μl, die in die rechte V. femoralis oder linke V. jugularis interna injiziert wurden.
Ergebnisse. Im Tierexperiment an Schweinen lassen sich venöse Luftembolien mit einer intravasalen Dopplersonde sicher detektieren. Die
detektierten Mikrogasblasen hatten ein Volumen von 3–6 μl.
Schlussfolgerung. Es ergab sich die Möglichkeit Luftembolien in der V. cava cranialis und V. cava caudalis durch eine in einen SVK integrierte
Dopplersonde sicher und zuverlässig zu erfassen. Damit könnte die klinische Überwachung vereinfacht und verbessert werden.
Problem. Air embolism frequently occurs under neurosurgical operations performed in the sitting position. Recently we reported the
idea of inserting a re-usable doppler probe into a blind-ending lumen of a central venous catheter (Schregel-Volk-Catheter,
SVC). In vitro testing in a circulation model showed a high sensitivity: air bubbles as small as 0.5 μl were reliably detected
at a distance up to 4 cm from the tip of the SVC.
Method. After approval by the local ethics committee pigs were anaesthetised and a cardiopulmonary bypass was connected. During the
bypass period a 12 F SVC (Medex Medical, Germany) with one blind-ending lumen was positioned into the proximal vena cava cranialis
or vena cava caudalis. An 8 MHz doppler probe (MTB Basler, Suisse) was introduced into the SVC and connected with the doppler
device Multi-Dop T (DWL, Germany). Well defined air bubbles (3–6 μl) were generated by a bubble generator and injected into
the right femoral vein or the left vena jugularis interna.
Results. All bubbles were reliably detected by the re-usable doppler probe. Embolic events can be documented, counted and quantified
by the Multi-Dop T.
Conclusion. Using SVC's with a blind-ending lumen could improve and simplify the detection of air embolism. We see several advantages
(e.g. sensitivity, costs) compared with established methods (precordial doppler, TEE) for detection of air embolism.
Der Anaesthesist 08/2002; 51(9):716-720. · 0.99 Impact Factor
