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S Geroulanos

Publications and source records attributed to S Geroulanos.

At least 19 recordsLinked to original sources
PubMed1998

Unexpected cardiac arrest after cardiac surgery: incidence, predisposing causes, and outcome of open chest cardiopulmonary resuscitation.

STUDY OBJECTIVES: To assess the incidence of acute mechanical causes precipitating sudden cardiac arrest in cardiac surgery patients during the immediate postoperative period. In addition, we report the success rate of cardiopulmonary resuscitation (CPR) in which open-chest CPR was employed at an early stage of the resuscitation effort. METHODS: Data on all cardiac surgical patients who suffered a sudden cardiac arrest during the first 24 h after surgery were collected prospectively. CPR consisted of conventional closed-chest CPR initially and was followed within 3 to 5 min, if needed, by open-chest CPR. RESULTS: Of 3,982 patients undergoing cardiac surgery over a 30-month period, 29 patients (0.7%) had a sudden cardiac arrest. Of these, 13 patients (45%) were successfully resuscitated with closed-chest CPR, 14 (48%) with open-chest CPR, and 2 (7%) died despite closed- and open-chest CPR. Four CPR survivors died subsequently in the ICU, yielding an overall hospital discharge rate of 79%. Perioperative myocardial infarction was the underlying cause of sudden cardiac arrest in 14 patients (48%), and mechanical impediments to cardiac function (tamponade or graft malfunction) in another 8 (28%) patients; in the remaining 7 patients (24%), no underlying cause was found. The length of ICU stay was 6+/-1 (mean+/-SE) days. None of the patients developed wound infection and all were neurologically intact at hospital discharge. CONCLUSION: Mechanical factors account for a substantial portion (28%) of causes of sudden cardiac arrest occurring in hemodynamically stable patients during the immediate postoperative period. This high incidence, in conjunction with the high survival rate achieved by open CPR, supports an early approach to open-chest CPR in this group of patients.

Cardiac Surgical Procedures↗
PubMed1998

Phrenic nerve dysfunction after cardiac operations: electrophysiologic evaluation of risk factors.

BACKGROUND AND STUDY OBJECTIVE: Phrenic nerve injury may occur after cardiac surgery; however, its cause has not been extensively investigated with electrophysiology. The purpose of this study was to determine by electrophysiologic means the importance of various possible risk factors in the development of phrenic nerve dysfunction after cardiac surgical operations. DESIGN: A prospective study was conducted. SETTING: A tertiary teaching hospital provided the background for the study. PATIENTS: Sixty-three cardiac surgery patients on whom surgical operations were performed by the same surgical team constituted the study group. Mean (+/-SD) age and ejection fraction were 63+/-5 years and 50+/-10%, respectively. INTERVENTIONS: Measurement of phrenic nerve conduction latency time after transcutaneous stimulation preoperatively and at 24 h and 7 and 30 days postoperatively. RESULTS: Thirteen patients had abnormal phrenic nerve function postsurgery, 12 on the left side and one bilaterally. Logistic regression analysis revealed that among the potential risk factors investigated, use of ice slush for myocardial preservation was the only independent risk factor related to phrenic nerve dysfunction (p=0.01), carrying an 8-fold higher incidence for this complication. In contrast, age, ejection fraction of the left ventricle, operative/bypass/aortic cross-clamp time, left internal mammary artery use, and diabetes mellitus were not found to be associated with phrenic neuropathy. The postoperative outcome of patients who received ice slush compared with that of those who had cold saline solution did not differ in terms of early morbidity and mortality. CONCLUSION: Among the risk factors investigated, only the use of ice slush was significantly associated with postoperative phrenic nerve dysfunction. Therefore, ice should be avoided in cardiac surgery, since it does not seem to provide additional myocardial protection.

Aged↗
PubMed1997

Low-dose amiodarone-related complications after cardiac operations.

OBJECTIVE: High-dose preoperative amiodarone therapy has been implicated as a risk factor for serious complications after cardiac operations. To investigate the effect of preoperative low-dose amiodarone treatment on early postoperative outcome after cardiac operations, we prospectively studied 88 patients. METHODS: Forty-four patients were receiving amiodarone (mean daily dose +/- standard deviation, 205 +/- 70 mg/day) and 44 patients were controls matched in pairs. The following parameters were recorded after the operation in all patients: (1) the ratio of oxygen tension to inspired oxygen fraction on arrival in the intensive care unit and 2, 4, 6, 10, 14, 18, and 22 hours thereafter; (2) the occurrence of acute respiratory distress syndrome; (3) early postoperative cardiac complications; and (4) the type and number of inotropic agents or vasopressors (or both) needed. RESULTS: No difference in the ratio of oxygen tension to inspired oxygen fraction was noted at the various time intervals between amiodarone-treated patients and control patients. Overall, only one patient had acute respiratory distress syndrome in the amiodarone group, but he had multiple other factors known to predispose to acute lung injury. Several cardiac complications, such as pulmonary edema, temporary pacing, and need for intraaortic balloon pump counterpulsation, were observed more frequently in amiodarone-treated patients than in control patients. In addition, amiodarone-treated patients required more frequent inotropic support (73% vs 43%, p = 0.003) and more inotropic drugs or vasopressors (or both) per patient than did control patients (1.4 +/- 1.1 vs 0.6 +/- 0.8, p = 0.002). CONCLUSION: Preoperative low-dose amiodarone therapy does not seem to be related to significant postoperative lung toxicity, but it is associated with various cardiac complications and an increased need for more intense inotropic support after cardiac operations. These findings may be related to the drug's depressant effect on the myocardium.

Amiodarone↗
PubMed1997

Systemic candidiasis in cardiac surgery patients.

OBJECTIVE: To examine the frequency, predisposing factors and consequences of systemic candidiasis in cardiac surgery patients. We also examined fluconazole efficacy in the treatment of disseminated fungal disease. METHODS: A total of 2615 adult patients of mean +/- S.D. age 60.8 +/- 8.7 years who underwent open heart surgery between July 1993 and April 1995, were enrolled in the initial protocol. Patients were divided in two groups according to length of stay in the intensive care unit (ICU). The cut-off was a length of stay of 9 days. RESULTS: In the group of patients with prolonged stay (n = 54), 11 patients (20.3%) developed systemic candidiasis, usually after the twentieth postoperative day. Predisposing factors were patient age, history of diabetes mellitus, presence of central venous catheters, prolonged mechanical ventilatory support, prolonged ICU stay, and administration of antibiotics and of total parenteral nutrition for a prolonged period. The patients who developed systemic candidiasis had a median ICU and hospital stay of 58 and 60 days respectively. The mortality rate was 27.2%. Patients receiving fluconazole, improved and eventually negative cultures were obtained. CONCLUSIONS: We concluded that a significant percentage of patients who remained in the cardiothoracic ICU for more than 9 days developed systemic candidiasis. Systemic candidiasis resulted in a significant prolongation of ICU and hospital length of stay, thus increasing extensively total hospitalization costs. Fluconazole seems to be an effective and well-tolerated agent in the treatment of severe life-threatening systemic candidiasis, and a very good alternative to amphotericin B, in cardiac surgery patients.

Adolescent↗
PubMed1997

Inspiratory maneuver effects on peak expiratory flow. Role of lung elastic recoil and expiratory pressure.

We investigated the effects of two different inspiratory maneuvers (fast or slow) on the ability of normal subjects to generate peak expiratory flows (PEF) and maximal dynamic expiratory pressures (Pexp) during the performance of a forced vital capacity maneuver. During the fast maneuver (F), the subject inspired rapidly to total lung capacity (TLC) and immediately performed a maximal expiration, whereas in the slow maneuver (S) the subject inspired slowly to TLC, paused for 4-5 s at TLC and then performed a maximal expiration. Ten normal subjects performed a series of such maneuvers. In addition to PEF and Pexp, we measured EMG activity of abdominal (EMGabd) and rib cage muscles, and lung elastic recoil pressure (PesL). Overall, F yielded higher PEF values than S (by approximately 7%); in addition, PesL, Pexp, rate of rise of Pexp (dPexp/dt), and EMGabd were similarly higher with F than with S (p < 0.05 for all). Analysis of individual data showed that the intermaneuver differences in PEF were largely explained by differences in PesL, Pexp or dPexp/dt. Our data suggest that, in comparison with the slow maneuver, the fast maneuver induces a greater change in both the lung elastic recoil and expiratory muscle activation which account for differences in PEF between the two maneuvers. The enhanced expiratory muscle activation with the fast maneuver suggests a specific inspiratory-expiratory muscle interaction analogous to agonist-antagonist interactions described for skeletal muscles.

Adult↗
PubMed1997

Relationship between left ventricular hypertrophy and plasma renin activity in chronic hemodialysis patients.

Left ventricular hypertrophy (LVH) is very common in uremic patients. It was shown previously that hemodialysis patients are chronically exposed to the extremes of plasma renin activity due to differences in the original renal disease. Because nonhemodynamic factors seem to play a fundamental role in the development of LVH, the present study was undertaken to investigate the relationship between the predialysis renin level and the echocardiographically determined cardiac structure in stable hemodialysis patients, matched for other parameters known to participate in the development of LVH, such as age; gender; body mass index; interdialytic weight gain; heart rate; systolic, diastolic, and mean arterial BP; hematologic and biochemical profile; vascular access; adequacy of dialysis; nutritional status; and period of follow-up. Thirty-three such patients were stratified in three groups according to predialysis renin levels: group A (n = 11), with renin levels < or = 1 ng.ml-1.h-1; group B (n = 9), with renin levels between 1 and 4 ng.ml-1.h-1; and group C (n = 13), with renin levels > or = 4 ng.ml-1.h-1. LVH with disproportionate septal thickening was directly related to the degree of renin-angiotensin system activation, and values for interventricular septum thickness, posterior wall thickness, interventricular septum thickness/posterior wall thickness ratio, left ventricular mass, and left ventricular mass index were all significantly correlated with predialysis renin levels. Because angiotensin II promotes growth in both fibroblasts and cardiac myocytes, these relationships suggest that elevated renin levels may be causally associated with the development of LVH in chronic hemodialysis patients.

Analysis of Variance↗
PubMed1997

Antibiotic prophylaxis in cardiac surgery.

BACKGROUND: A prospective, randomised study was conducted among 1009 cardiac surgery patients in order to compare the prophylactic efficacy of a second generation cephalosporin (cefuroxime) given as single shot, versus a broad spectrum double regimen (amoxycillin-netilmicin). METHODS: Cefuroxime received 501 patients (Group A), while a 4-day combination of amoxycillin-netilimicin 508 patients (Group B). RESULTS: There were found no statistically significant differences either in infection rate or the kind of infection between the two groups. Single shot cefuroxime prophylaxis was just as effective, as a 4-day combination of amoxycillin and netilmicin. Total infection rate was 5.6% (n=28) in Group A and 5.7% (n=29) in Group B. Respiratory tract infection was the most frequently registered in both groups; 2.6% in Group A and 2.9% in Group B. Sternal wound and catheter-related infection rates were 0.6% and 1% in both groups, respectively. There were no side effects due to the given antibiotics. CONCLUSIONS: A single shot of cefuroxime prophylaxis is equally effective and safe as a 4-day regimen with amoxycillin and netilmicin.

Aged↗
PubMed1996

Comparison of gastric air tonometry with standard saline tonometry.

OBJECTIVE: To compare partial pressure of carbon dioxide (PCO2) measurements obtained by sampling gastric intraluminal air with those obtained by standard saline tonometry. DESIGN: Prospective, unblinded study. SETTING: Intensive care unit in a tertiary cardiac surgical center. PATIENTS: 20 patients undergoing cardiac surgery. INTERVENTIONS: Gastric tonometric catheters were inserted, gastric fluid was aspirated, and 100 cc of air was injected into the stomach. MEASUREMENTS: After an equilibration period of 30 min, samples of gastric air and saline were anaerobically aspirated and analyzed on a standard blood gas machine. The reproducibility of PCO2 measurements in a given patient was assessed by analyzing consecutive samples of gastric air and calculating the coefficient of variation (CV). RESULTS: PCO2 values measured in samples of gastric air (PCO2 air) were highly correlated with those derived by saline tonometry (PCO2ss)(r2 = 0.95, p = 0.0001); PCO2 air was significantly greater than PCO2ss (50 +/- 17 vs 48 +/- 17 mmHg, p = 0.0001). Intramucosal pH (pHi) calculated from PCO2 air was significantly lower than that calculated from PCO2ss (7.26 +/- 0.23 vs 7.28 +/- 0.24, p = 0.0001). Analysis of intermethod differences showed significant bias for both PCO2 (2.4 +/- 7.6 mmHg, mean +/- 2SD, bias +/- precision) and pHi ( -0.023 +/- 0.074, mean +/- 2SD, bias +/- precision). The within-subject variability of replicate PCO2 measurements in gastric air was low (CV = 2.6 +/- 0.8). CONCLUSION: We conclude that intraluminal PCO2 can be accurately determined in postoperative cardiac surgery patients by instilling air into the stomach and analyzing samples of gastric air on a standard blood gas machine, In comparison with saline tonometry, air tonometry consistently yields lower pHi values.

Aged↗
PubMed1996

Clinical outcome and immunology of postoperative arginine, omega-3 fatty acids, and nucleotide-enriched enteral feeding: a randomized prospective comparison with standard enteral and low calorie/low fat i.v. solutions.

In a prospective randomized trial in patients undergoing major abdominal surgery, the impact of a new enteral formula supplemented with arginine, omega-3 fatty acids, and nucleotides (A, n = 14) on immunological parameters was compared with a standard enteral formula (B, n = 14) and a low calorie/low fat intravenous solution (C, n = 13). Four days postoperatively, a statistically significant decrease in total leukocyte count (A, 9.0 +/- 2.9; B, 8.0 +/- 2.4; C, 11.1 +/- 3.5 x 10(6) cells/mL; A versus C, B versus C; p < 0.05), higher percentage of lymphocytes (A, 14.3 +/- 4.9; C, 8.2 +/- 6.1; p < 0.05), and decreased median CRP levels (A, 80.4 [69.9]; B, 70 [74]; C, 88.5 [142] in mg/L; A versus C, p < 0.05; B versus C; p < 0.05) were observed in the enteral nutrition groups. The expression of activated surface antigen HLA-DR was diminished on CD14+ cells over 4 d (A, 58.2 [39.2]; B, 52.2 [36.2]; C, 76.6 [25.2] in %; A versus C, p < 0.05; B versus C, p < 0.05) and 8-10 d (A, 37.9 [31.4]; C, 58.5 [37.6]; p < 0.05) postoperatively. Significantly enhanced median phagocytic activity of CD14+ monocytes and granulocytes was observed in group C 8-10 days postoperatively (A, 83.3 [11.8]; B, 71.6 [34.1]; C, 87.4 [10.8]; A versus B, B versus C, p < 0.05; and A, 75.7 [10.0]; B, 69.0 [37.8]; C, 80.0 [10.1] in %, B versus C, p < 0.05, respectively). Postoperative hospital and intensive care unit stay was similar among the three groups; however, infectious complications were less frequent in group A (A versus C, p = 0.15). Thus, a modified enteral nutritional support and supplementation may influence the immune competence toward a more efficient defense response.

Aged↗
PubMed1996

Determinants of duration of ICU stay after coronary artery bypass graft surgery.

Prediction of duration of a patient's stay in the ICU after cardiac surgery is difficult. In 652 consecutive adult patients undergoing elective coronary artery bypass graft (CABG) surgery, we analysed prospectively preoperative and immediate postoperative variables thought to influence duration of stay in the ICU. With univariate analysis, we found that age, preoperative left ventricular ejection fraction, bypass time, aortic cross-clamp time, blood transfusions and the number of inotropic agents administered in the immediate postoperative period (for at least 6 h) were significant correlates of duration of stay in the ICU. However, logistic regression analysis showed that the number of inotropes was the most important determinant of stay in the ICU, with an overall prediction accuracy of 94.8%. The main cause of prolonged stay in the ICU (more than 2 days) was low cardiac output syndrome. We conclude that analysis of perioperative variables enhanced our ability to accurately predict duration of stay in the ICU in cardiac surgery patients. The number of inotropic agents administered during the first 6 h after operation was the most important determinant of duration of stay in the ICU.

Adult↗
PubMed1994

Reduced endogenous nitric oxide in the exhaled air of smokers and hypertensives.

We wanted to determine whether the production of endogenous nitric oxide (NO) is affected by cigarette smoking and various pathological conditions. Endogenously produced NO was measured by chemiluminescence in the exhaled air of 81 healthy volunteers (21 nonsmoking females (NSF), 12 smoking females (SF), 24 nonsmoking males (NSM) and 24 smoking males (SM)) and 38 patients (10 with hypertension, 10 intra- and 10 postoperative, 5 with renal failure and 3 with sepsis) entered the protocol. Subjects inspired from a NO-free air supply, which was also used to calibrate the NO-analyser. Endogenous NO production of volunteers was 18 +/- 8 per billion (ppb) depending on smoking habits. In exhaled air of NSF, NO concentration was 21 +/- 7 ppb, in SF 16 +/- 6 ppb, in NSM 19 +/- 8 ppb and in SM 15 +/- 6 ppb. Differences between smokers and nonsmokers were significant. Increased diastolic blood pressure was noted in SM compared to NSM (86 +/- 7 versus 78 +/- 7 mmHg). Patients with documented and treated hypertension (systolic and diastolic blood pressure: 141 +/- 18 and 82 +/- 9 mmHg) exhaled 13.7 +/- 5.3 ppb NO; hypertensive males 10 +/- 2 ppb NO and females 17 +/- 5 ppb NO. In patients with renal failure NO concentration in exhaled air was 20.2 +/- 6.8 ppb before and 19.8 +/- 6.4 ppb one hour after the onset of dialysis. In patients undergoing major surgery NO concentration was 5.6 +/- 2.5 ppb intra- and 10.3 +/- 3.5 ppb postoperatively. In three mechanically ventilated patients with documented septic syndrome, exhaled NO was 29.3 +/- 24 ppb.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

[The first successful lung resection].

In 1883 Krönlein resected a sarcoma of the ribs in an 18 year old female. Six months later he reoperated the patient for a local recurrency. At the second operation which necessitated a wide exposure of the thoracic cavity he deliberately removed a pulmonary metastasis about the size of a walnut. Two years later a new recurrence had to be resected. The three interventions led to a survival of 7 years. The patient succumbed to a further recurrence in 1890. Krönleins operation opened two new chapters in surgery, pulmonary interventions in general and in particular surgery of pulmonary metastasis. Surgery of lungs was not a topic of that era, particularly since some incisions for abscesses and resections of pulmonary parenchyma had not been successful. By limiting the indication to patients with sufficient pulmonary function and by following the successful pneumonectomy experiments in animals Krönlein favored pulmonary resection. The success of this intervention confirmed these considerations especially since it lasted for years. It was followed in 1885 by a pulmonary resection by G. Ruggi in Bologna. Surgery of the lung, however, came in general use only 50 years later.

Germany↗
PubMed1993

A new approach in the treatment of hypotension in human septic shock by NG-monomethyl-L-arginine, an inhibitor of the nitric oxide synthetase.

NG-monomethyl-L-arginine (L-NMMA) is an inhibitor of the enzyme nitric-oxide-synthetase. Nitric oxide (NO), produced by endothelial and vascular cells regulates physiological vascular tone, blood pressure and tissue perfusion via guanylate-cyclase and cGMP. In an advanced stage of therapy resistant septic shock in response to inflammatory mediators, NO is overproduced. This leads to vasodilatation, a fall in systemic blood pressure and an attenuated vasoconstriction-response to sympathetic-stimuli. Two episodes of severe and prolonged hypotension in a patient with sepsis were successfully treated twice by bolus therapy of L-NMMA within 4 weeks. On both occasions blood pressure was reversed to normal and the continuous use of high doses of catecholamines were stopped. In contrast to the immediate response of blood pressure, heart rate and central venous pressure remained stable. Cardiac output dropped to 68% and PaO2 increased. These findings indicate that NO-synthetase-inhibitors may be of value in the therapy of human septic shock.

Adult↗
PubMed1993

Randomized comparative trial of imipenem/cilastatin versus aminoglycoside plus amoxycillin plus clindamycin in the treatment of severe intra- and post-operative infections.

In a prospective, randomized, controlled study, clinical and bacteriological efficacy of imipenem/cilastatin (I/C) was compared with a standard combination of aminoglycoside + amoxycillin + clindamycin (C) in patients (pts) with severe intra- and postoperative infections. A total of 84 pts were randomly separated into two groups of 42 pts. Diagnoses were pneumonia n = 21 (14 in I/C group and 7 in C), peritonitis n = 45 (16 in I/C group and 29 in C), septicaemia n = 12 (9 in I/C group and 3 in C), and 7 other infections (3 in I/C group and 4 in C). Doses used were imipenem/cilastatin 1 g q 8 h and amoxycillin 2 g q 8 h plus clindamycin 0.6 g q 6 h, plus netilmicin according to serum concentrations. Success rates were 85.4% (n = 35: 34 cured and one improved) in the I/C group and 83.3% (n = 35: 30 cured and five improved) in the C group. Six pts in group I/C and 7 in group C failed to respond to treatment. One patient in the I/C group was not assessable. 62% of the bacterial isolates were eradicated in the I/C group and 55% in group C. 7% were suppressed in I/C and 5% in C. It is concluded that imipenem/cilastatin is an effective and well-tolerated alternative to antibiotic combinations in severe intra- and post-operative infections. It offers the advantages of fewer drug doses and less renunciation of serum drug concentration monitoring.

Aminoglycosides↗
PubMed1993

Antibiotic prophylaxis in cardiovascular surgery: a prospective randomized comparative trial of one day cefazolin versus single dose cefuroxime.

With the intention of reducing prophylactic antibiotic dosage, previous studies in the Zurich University Hospital have shown that a one/day prophylactic antimicrobial regimen with cefazolin was as effective as a single dose of ceftriaxone. In this prospective randomized study one day cefazolin prophylaxis (1 g q 8 h i.v.) was compared with a single dose of cefuroxime prophylaxis (1.5 g). In cases of cardiopulmonary bypass 0.75 g was added in the priming solution. In case of re-operation prophylaxis was repeated. 496 patients were enrolled in the study protocol; 78 patients were subsequently excluded. Of the remaining patients 224 (158 male, 66 female, mean age 61) were in the cefazolin group and 194 (142 male and 52 female, mean age 60) in the cefuroxime group. Mean duration of the intensive care unit (ICU) stay was three days in both groups and mean hospital stay was 16 days in the cefazolin group and 15 days in the cefuroxime group. The overall postoperative infection rate was 15.3%; 18.8% in the cefazolin group and 11.3% in the cefuroxime group. The statistical differences were found as in trend (p = 0.095). The lower incidence of infectious complications in the single cefuroxime dose group may indicate an improvement in effectiveness of antimicrobial prophylaxis: it offers patients a reliable antimicrobial protection. In addition, the single dose prophylaxis has the advantage of easier handling, reduced dosage frequency and lower cost.

Bacterial Infections↗
PubMed1993

[Thoracopagus symmetricus. On the separation of Siamese twins in the 10th century A. D. by Byzantine physicians].

The byzantine author, Leon Diakonos, mentions in 974/975 A.D. a pair of "siamese twins", e.g., a thoracopagus symmetricus. He had seen them personally several times in Asia Minor when they were about 30 years old. This pair is possibly the same that was "successfully" surgically separated after the death of one of the twins in the second half of the 10th century in Constantinople. This operation is mentioned by two historiographs, Leon Grammatikos and Theodoros Daphnopates. Although the second twin survived the operation, he died three days later. In spite of its lethal outcome, the operation left a long-lasting impression on the historians of that time and was even mentioned 150 years later by Johannes Skylitzes. Furthermore, the manuscript of Skylitzes, now in the library of Madrid, contains a miniature illuminating this operation. This is likely to be the earliest written report of a separation of siamese twins illustrating the high standard of byzantine medicine of that time.

Adult↗
PubMed1993

[Lung abscess: evolution of a complication over 45 years].

143 patients with lung abscesses were hospitalised at the Department of Surgery at University Hospital Zurich from 1946 to 1990. Analysing our patients in a retrospective study we concluded as follows: 1. Lung abscesses have nearly disappeared in our patients. 2. Lung abscesses can be cured without lethality. 3. Cancers of the lung causing abscesses were not seen any more since 1960. 4. A compromised immunological system appeared as a new pathogenetical factor since the beginning of the 1980ies.

Cause of Death↗