Biomedical subjects

G Drossos

Publications and source records attributed to G Drossos.

9 recordsLinked to original sources

PubMed2006

Successful cardiac and cerebral resuscitation with extracorporeal circulation and mild hypothermia.

Extracorporeal circulation could be effective for cardiac resuscitation in patients who do not respond to ''Advanced cardiac life support'' (ACLS), but cannot guarantee brain survival. A case of successful cardiac and cerebral resuscitation with extracorporeal circulation and mild hypothermia, in a 48 year-old man with cardiac arrest due to cardiac tamponade, is reported. The good long term neurologic outcome of the patient is also described.

Cardiopulmonary Resuscitation↗

PubMed2003

"Learning curves" of cardiac surgery in relation to risk stratification and hospital location.

AIM: The purpose of this study was to determine any significant differences in "learning curves" between private and public hospitals when the same senior surgeon was responsible during the initial phases of open-heart surgery programs development, in relation to risk stratification and hospital location. METHODS: A prospective review of 610 patients records was performed at a newly-opened cardiothoracic program in a public University Hospital (PUH) in the periphery of Greece, and a private institution (PI) with an experienced intensive care unit (ICU) in the capital city of Athens. Preoperative risk stratification, mortality and postoperative length of stay (LOS) were analysed between 1999 to 2001. RESULTS: At PUH 298 patients were operated and 312 patients at PI. There were 136 low risk (EuroSCORE 0-2) and 474 medium and high-risk patients (EuroSCORE > or =3). There was no significantly elevated mortality or learning curve in low risk surgery either at PUH (57 patients with 1 death) or PI (79 patients and 1 death). In medium and high-risk surgery at PI there was no mortality in 68 patients operated by the senior surgeon and no learning curve in all 233 such patients. In 240 medium and high-risk patients at PUH there was a learning curve despite the involvement of the same senior surgeon. In 1999 and 2000 the observed mortality (OM) in 150 patients was 15.33%, EuroSCORE 5.98, and in 2001 in 91 patients OM 3.29%, EuroSCORE 5.95 with p=0.00.8 when "experienced" ICU staff was employed. LOS was significantly reduced in 97 patients in 2001 at PUH (8.7 d +/- 2.81 vs 11.07 days +/- 7.9 in 1999 and 2000, p=0.046) confirming the existence of a learning curve at the PUH. No such change was observed at PI (8.2 days vs 7.8, p=0.45). CONCLUSION: No mortality differences or learning curve characteristics were detected for low risk operations either at PUH or PI. For medium and high risk surgery there appears to be a learning curve in PUH but not in PI despite senior surgeon involvement in both. The presence of an experienced ICU appears to play a critical role in the outcome of operations in newly opened cardiothoracic programs.

Analysis of Variance↗

PubMed2001

Possible intra-aortic balloon pump "function-related" mechanism of embolic events in patient with protruding atheroma in the thoracic aorta.

A possible new functional mechanism of atheromatous embolus is presented resulting from reversed aortic blood flow during diastolic augmentation by balloon counterpulsation. This mechanism is different from mechanical disruption during insertion. Despite this, intra-aortic balloon remains an important asset in the management of hemodynamically challenged patients.

Aorta, Thoracic↗

PubMed2001

Prevention of aortic anastomotic hemorrhage. A simplified intraoperative testing technique.

BACKGROUND: Postoperative bleeding in aortic root aneurysms had represented a challenge. METHODS: Intraoperative testing of the annular or subannular aortic anastomosis, during procedures involving replacement of the aortic root, with either synthetic tube graft, a composite graft or an allograft is described. By reversing the flow of the LV vent and delivering cardioplegia into the left ventricle and thereby pressurizing the left ventricle and its outflow, this technique enables the surgeon to simulate the volume loaded heart, prior to completion of the distal anastomosis. A systematic assessment of the proximal suture line can then be undertaken. Portions of the proximal suture line, particularly the posterior aspect, are obscured if the inspection takes place after completion of both aortic anastomoses, the coronary attachments, as well as from the presence of the main pulmonary artery and by the distended aorta itself. RESULTS: The use of this method in 34 patients is described without untoward events related to this technique. CONCLUSIONS: The advantages of this technique are a rapid and safe assessment of the integrity of the proximal suture line bed.

Adolescent↗

PubMed2000

Oxidative status and anti-oxidant enzyme activity during calcium paradox in the rat isolated heart.

1. The effect of calcium paradox on oxidative status and the activity of anti-oxidant enzymes were studied in the rat isolated heart. Glutathione status, sulphydryl group contents and lipid peroxidation in the myocardium, as well as the release of oxidized and reduced glutathione from the heart, were taken as indices of oxidative events. 2. Reperfusion with calcium after calcium-free perfusion induced a significant decrease in the myocardial content of reduced and oxidized glutathione and non-protein sulphydryl groups. At the same time, a significant release of both forms of glutathione from the heart was observed. However, the ratio of oxidized to reduced glutathione remained unchanged and was not different from control. Increased lipid peroxidation was observed only after 30 min of reperfusion with calcium. 3. Increased anti-oxidant activity during the reperfusion period was observed. Mitochondrial Mn-superoxide dismutase (SOD) activity was increased throughout the reperfusion period, while cytoplasmic Cu,Zn-SOD and glutathione peroxidase activity showed a transient increase at 5 min reperfusion. 4. The results do not support an important role of oxygen free radicals in cell damage observed during calcium paradox in the rat isolated heart. Production of oxygen free radicals may occur during the reperfusion period, but the quantity produced is insufficient to exceed the anti-oxidant capacity of the heart.

Animals↗

PubMed1995

Enzymatic evaluation of renal damage caused by different therapeutic procedures for kidney stone disease.

In an attempt to evaluate renal injury relative to open surgery, percutaneous nephrolithotripsy (PCN) and extracorporeal shock wave lithotripsy (ESWL) were studied in 52 patients with renal calculus disease. Preoperative and postoperative urinary levels of N-acetyl-glycosaminidase (NAG), a sensitive marker of renal tubular damage, were studied. No significant changes were noted in posttreatment urinary NAG values among patients who underwent ESWL or PCN. Although statistically nonsignificant, a constant mild increase of urinary NAG was observed after PCN, that has to be evaluated with long-term follow-up studies. The shock wave number or power in cases treated with ESWL as well as the number of renal punctures in the PCN group did not change the effect on renal tubular function. Diabetics and patients with chronic renal disease treated by ESWL did not show any significant change in posttreatment urinary NAG levels. In contrast to that, all patients treated by open surgery had significant, intense and prolonged increase of the postoperative NAG values, especially those treated by ischaemic nephrolithotomy. Comparing the three different therapeutic modalities, open surgical procedures had the most significant effect on renal function and this difference was statistically significant. We therefore suggest that ESWL does not endanger renal function, while open surgery must be reserved for selected cases.

Acetylglucosaminidase↗

PubMed1995

Deferoxamine cardioplegia reduces superoxide radical production in human myocardium.

Recent studies have demonstrated enhanced myocardial protection during ischemia using the oxygen free radical scavenger, deferoxamine. This effect of deferoxamine may be related either to its iron-chelating property or to intervention in an iron-independent mechanism. We tested the latter by determining the rate of superoxide anion production and the degree of lipid peroxidation in human myocardial tissue after including deferoxamine in cardioplegic solution. Fourteen patients who underwent aortic, mitral, or double valve replacement were included in the study. The mean value for superoxide radical production was 59.8 +/- 17.0 nmol.min-1.g-1 for the control group (group C; n = 7) and 21.3 +/- 8.1 (p < 0.001) for the deferoxamine-treated group (group D; n = 7). The mean value for thiobarbituric reactive substances was 80.00 +/- 23.4 in group C and 38.7 +/- 23.8 nmol.min-1.g-1 in group D (p < 0.01). In conclusion, deferoxamine appears to have a moderating effect on the biochemical markers of ischemia reperfusion injury. Its scavenging effect on superoxide anion could play a role in the cellular defense against oxygen radicals during cardiac operations.

Aged↗

PubMed1995

Posttraumatic coronary artery aneurysm.

A 31-year-old man sustained blunt deceleration trauma with dissection of the left anterior descending coronary artery. We repaired a posttraumatic coronary aneurysm to prevent late occlusion of the recanalized vessel. An internal mammary artery graft was applied as a precaution against postoperative thrombosis. Follow-up at 12 months showed improved left ventricular function.

Accidents, Traffic↗

PubMed1994

Aprotinin and bleeding in profoundly hypothermic perfusion.

Clinical observation led us to believe that aprotinin fails to preserve haemostatic function in patients undergoing deep hypothermic perfusion with or without circulatory arrest. A retrospective study was made of blood loss in 80 consecutive acute Type A dissection patients before and during the aprotinin era (1987-1992). After 1988 all patients were cooled below 20 degrees C pending circulatory arrest. Fourteen patients underwent aortic root replacement and 66 replacements of the ascending aorta. Age distribution (range 22-79 years) and type of operation were similar in the aprotinin and control groups. The impervious Hemashield (Meadox) graft was used for all but five patients. These underwent aortic root replacement with preclotted, valved conduits. Overall the mean blood loss for 27 patients operated without aprotinin was 837 ml per 24 h (standard error +/- 90) and for 53 patients with aprotinin 1,929 ml per 24 h (standard error +/- 90). There was a significant difference between the two groups when profoundly hypothermic perfusion was used, with greater bleeding in aprotinin-treated patients. There were six re-entries in the aprotinin group and none in the control patients. There were ten hospital deaths (11.1%). A greater incidence of bleeding and thrombosis-related deaths was recorded for the aprotinin-treated patients. In addition, four surviving aprotinin patients suffered severe coagulation defect with blood loss greater than 4,500 ml and platelets less than 50 x 10(6). We suggest that aprotinin inhibits the protease enzymes which maintain the fluid state of blood during hypothermic low flow and arrest states. Disseminated intravascular coagulation may consume platelets thereby predisposing to abnormal bleeding and potentially fatal thrombotic events. The use of aprotinin in profoundly hypothermic perfusion should be adopted cautiously.

Adult↗