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Biomedical subjects

S Necek

Publications and source records attributed to S Necek.

At least 19 recordsLinked to original sources

Monitoring intravascular volumes for postoperative volume therapy.

BACKGROUND AND OBJECTIVE: The feasibility of monitoring measured intravascular volumes and the cardiac filling pressures were compared to reflect the optimal volume status of postoperative patients. METHODS: In a prospective clinical study, 14 hypovolaemic adult patients were included after cardiac surgery. All patients received 1,000 mL hydroxyethyl starch after meeting the authors' criteria for hypovolaemia. Pressures were measured by use of a pulmonary artery catheter and volumes were determined by double-indicator dilution technique. RESULTS: Stroke volume index (SVI), central venous pressure (CVP), pulmonary artery occlusion pressure (PAOP), intrathoracic blood volume index (ITBVI) and total circulating blood volume (TBVIcirc) increased significantlyaftervolumeloading(30.7 +/- 9.8 to 41.7 +/- 9.6 mLm(-2), 4.9 +/- 1.7 to 9.1 +/- 2.3mmHg, 6.6 +/- 1.3 to 10.6 +/- 1.9 mmHg, 858 +/- 255 to 965 +/- 163 mLm(-2), and 1,806 +/- 502 to 2,110 +/- 537 mLm(-2), respectively). During the subsequent 1 h steady-state period, CVP and PAOP decreased significantly (9.1 +/- 2.2 to 7.4 +/- 2.2 mmHg and 10.6 +/- 1.9 to 9.2 +/- 2.0 mmHg, respectively), whereas SVI and intravascular volumes remained unchanged. The changes of CVP and PAOP did not correlate with changes in stroke volume during volume loading (r2 = 0.06 and 0.03, respectively) and during steady-state (r2 = 0.17 and 0.00 respectively). On the other hand, a significant correlation was found between changes of the intrathoracic blood volume and changes in stroke volume during the volume loading (r2 = 0.67) and also during the steady-state phase (r2 = 0.83). CONCLUSIONS: Intrathoracic blood volume reflects more accurately the preload dependency of cardiac output in postoperative patients than left/right-sided cardiac filling pressures.

Adult↗

[Anesthesiology and day surgery].

The day surgery, known also as an office based practice, is a major change in the clinical medicine of the last two decades. In some countries (for instance in Austria) exists a clear difference between the ambulatory and the day surgery. While the ambulatory patient does not need a hospital bed at all, the day surgery patient occupies a bed for at least few hours, but never stays in the unit overnight. The shift from the hospital to extrahospital surgery is dictated by economical pressure on hospitals, are made possible by new non-invasive surgical techniques and new anaesthetic drugs and, finally, demanded by the society. Anaesthesiologists play a major role in this development, their main task in this new scenario is to secure a balance between the "fast track" approach ot the out-patient surgery and the patient's safety. The meticulous application of the standards in monitoring and perioperative care is the primary obligation of an anaesthesiologists. There is no clear definition of the magnitude of the operation, which can be performed in the settings of day surgery, it varies according to organisation of such units and from the proximity of the hospital in its background. Generally from the day surgery programs should be excluded patients with the risk class above ASA 2, operations lasting more then 90 minutes, all intracranial and intrathoracic operations and all procedures requiring blood transfusion. Day surgery is generally free from mortality and major complications like myocardial infarction, pulmonary embolism or neurological consequences, therefore the assessment of outcome should include minor morbidity, pain relief and satisfaction of the patient.

Ambulatory Surgical Procedures↗

Haemodynamic changes during thoracoscopic surgery the effects of one-lung ventilation compared with carbon dioxide insufflation.

We investigated the haemodynamic and respiratory effects of one-lung ventilation and carbon dioxide insufflation in 13 adult patients undergoing video-assisted thoracoscopy. Cardiorespiratory variables were determined during carbon dioxide insufflation at intrahemithoracic pressures of 5, 10 and 15 mmHg, and after 5 and 15 min of one-lung ventilation. Carbon dioxide insufflation was associated with a clear deterioration in circulatory function. The cardiac index decreased subsequent to increasing intrathoracic pressures. The mean cardiac index (SD) at pressures of 10 and 15 mmHg was 1.86 (0.39) and 1.52 (0.46), respectively, and may be compared with the reduced venous return consistent with tension pneumothorax. One-lung ventilation did not affect haemodynamic variables but reduced arterial oxygenation indices (PaO2/FIO2) from 424.29 (160.79) after induction of anaesthesia, to 207.72 (125.50) after 5 min and 172.04 (72.03) after 15 min of one-lung ventilation, respectively. The oxygenation index was not influenced by intrahemithoracic carbon dioxide insufflation. One-lung ventilation via a double-lumen endobronchial tube is safe and convenient for video-assisted thoracoscopic surgery. It has no further consequences on haemodynamic variables, whereas the compression of the lung by carbon dioxide insufflation may cause circulatory dysfunction.

Adult↗

[Comparison of postoperative volume therapy in heart surgery patients].

UNLABELLED: Patients who have undergone cardiac surgery with use of extracorporeal circulation frequently reveal marked hypovolaemia in spite of a highly positive fluid balance. This is thought to be due to transient microvascular damage and extravascular fluid shift. Further volume replacement to achieve haemodynamic stability in the postoperative period may cause fluid overload and congestive heart failure. The present study was designed to investigate whether this fluid overload could be avoided by using a hypertonic-hyperoncotic solution (group I: HHL, 10% hydroxyethylstarch 200/0.5 in 7.2% saline) instead of two different standard colloid solutions (group II: HA, 5% albumin; group III: HES, 6% hydroxyethylstarch in 0.9% saline). METHODS: Twenty-one patients meeting our criteria for hypovolaemia immediately after cardiac surgery were randomly assigned to three groups. Patients in group I received HHL in increments of 150 ml, while patients in group II and group III were given HA and HES respectively in increments of 500 ml until hypovolemia was corrected. Haemodynamic assessment was done using a pulmonary artery thermodilution catheter. Intra- and extravascular volumes, including extravascular lung water (EVLW), intrathoracic blood volume (ITBV), and total blood volume (TBV) were measured by the double indicator technique using lung water software (COLD-System, Pulsion, Munich, Germany). RESULTS: Correction of hypovolaemia-related haemodynamic parameters and restoration of normal TBV were achieved by 236 +/- 80 ml of HHL (group I), 857 +/- 244 ml of HA (group II) and 1000 +/- 0 ml of HES (group III) respectively. TBV increased significantly in each group, compared to baseline values. EVLW did not change significantly in any group. We found that the volume-augmenting effect of HHL per millilitre infused solution was more than four times that of HA and HES, primarily as a result of increasing plasma osmolality due to an increase of plasma sodium levels. This pronounced effect on intravascular volume of HHL lasted for only 2 h following infusion, however, and did not lead to any unwanted side effects. In the period between 2 and 20 h after primary volume replacement, further fluid therapy with colloids and crystalloids, guided by clinical signs of hypovolaemia, was necessary in each group of patients. The overall fluid requirements for the first 20 h after operation did not differ among the three resuscitation regimens. CONCLUSION: We found that HHL is a safe and effective solution for acute correction of hypovolaemia after cardiac surgery. The advantages of a smaller initial volume load by HHL cannot be maintained for longer than 2 h.

Adolescent↗

Improvement in prognosis of patients with acute renal failure over a period of 15 years: an analysis of 710 cases in a dialysis center.

In order to evaluate the changes in causes and outcome of acute renal failure (ARF) during the years 1975-1989, 710 patients treated in our dialysis center were analyzed. We compared the etiology, the severity and catabolic state of ARF, the techniques of renal replacement therapy, which were employed and the ages and mortality rates of these patients, who received dialysis therapy during the years 1975-79 (n = 227), 1980-84 (n = 240) and 1985-89 (n = 243). The number of postoperative, posttraumatic and non-traumatic cases of ARF was approximately the same in all three 5-year periods, only the frequency of postrenal failure decreased from 7% in the years 1975-79 to 3% in the years 1985-89. The incidence of sepsis as a major cause of ARF and the most important risk factor was comparably high in the surgical and medical patients during all of the periods, but it increased in the traumatic patients from 7% in the years 1975-79 to 28% during the last 5-year period. The prevalence of respiratory failure and jaundice as additional organ failures, the severity of ARF (oligonanuric-nonoliguric) and the metabolic state were not different in the three patient groups. The magnitude of rise in serum creatinine before the start of renal replacement therapy was significant lower in the last 5-year period in comparison to the years 1975-79 (p < 0.05). Hemodialysis was the treatment in choice of 98 and 93% of the cases during the first two periods, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Kidney Injury↗

Effects of high-dose aprotinin on blood loss, platelet function, fibrinolysis, complement, and renal function after cardiopulmonary bypass.

The use of aprotinin to reduce blood loss after cardiopulmonary bypass is under debate. Concern has been raised about the renal effects of aprotinin. We administered a mean aprotinin dose of 4.2 x 10(6) kallikrein-inhibiting units to 13 patients with coronary disease undergoing cardiopulmonary bypass for 74 +/- 5 minutes (mean +/- standard error of the mean); 13 comparable patients having cardiopulmonary bypass served as control subjects, and all were studied postoperatively for 24 hours. Aprotinin reduced postoperative blood loss by 50% (p = 0.0082). Two of the 13 patients who received aprotinin needed one red cell unit each versus a total of 18 units in eight of 13 control patients (p = 0.0096). Blood pressure, hemoglobin value and serum protein concentration were higher after operation in the aprotinin group (p less than 0.05 to p less than 0.01). Platelet counts did not differ, but plasma thromboxane was lower in aprotinin recipients (p less than 0.001). In control patients fibrinogen degradation products (D dimer) doubled, and alpha 2-antiplasmin activity was halved during and after cardiopulmonary bypass (p less than 0.01 to p less than 0.001), whereas aprotinin patients showed no changes. The complement breakdown products C4a, C3a, and C3dg as well as C9 neoantigen increased from prebypass baseline in both groups (p less than 0.001); the increment of C3a and C3dg was greater in the aprotinin than in the control patients (p less than 0.001). Serum electrolytes, osmolality, and creatinine remained normal in both groups of patients. Creatinine clearance was normal or above normal and virtually identical in both groups. Osmolar clearance and fractional sodium excretion were higher in the aprotinin group than in the control group shortly after cardiopulmonary bypass (p less than 0.05 to p less than 0.01); renal function was unremarkable the next morning. No adverse clinical effects attributable to aprotinin were seen. In summary, aprotinin offers advantages for cardiopulmonary bypass.

Antithrombin III↗

[Anesthesiologic considerations in non-university heart surgery].

The non-debatable need for expansion of cardiac surgery beyond the university hospitals was recognized in Austria ten years ago. Such development put an additional strain on the scarce resources of Anesthesia Service and Intensive-Care-Unit (ICU) facilities. To cope with the increase of the ICU patient load the change of ICU admission and discharge criteria was necessary. The economic burden for the hospital was in our case a limiting factor for the number of heart operations, soon the emergency cases and high-risk cardiac patients forced the hospital administration to accept the reality. It took more than five years to change from necessary improvisation to full organization of the Cardiac Service which is presently interwoven into the existing hospital structures. Such interdisciplinary solution (surgery, medical service, anesthesia) is in authors' opinion superior to an isolated cardiac surgical center.

Anesthesia Department, Hospital↗

[The concept of an emergency admission unit in a major community hospital].

The main task of a central interdisciplinary emergency admission unit (EAU) staffed and administered by the anesthesia department is to provide primary hospital treatment for emergency patients. The EAU serves also as a base for the emergency ambulance and functions as a 24-hour resuscitation unit for the whole hospital. The placement of the unit in the underground floor of the hospital makes it easy accessible for ambulances but excludes walk-in patients. The shock room has a floor area of 152 m2 and is optimally equipped, while two smaller emergency rooms provide reserve accommodation. On the same level are the X-ray department, emergency operating room, trauma team taking care of minor injuries and the medical house officer. The last two and the admissions clerk are responsible for selecting the real emergencies out of 9000 of urgent cases and patients with minor traumas entering the hospital on this level. In the first 40 months of EAU activity 1.2% of total hospital admissions (300-400 patients from a total number of 33,000 a year) were treated in the EAU; 71% of emergencies arrived by our own emergency ambulance or by helicopter, while others were brought by the Red Cross Emergency Service. The majority of acute cases (42.7%) are traumatic; 17.4% have circulatory problems, 10.8% neurological problems, 10.1% are suicidal, 1.5% are dead on arrival and the rest (17.5%) has other origins. From the total number of 1046 living admissions, 99 patients required cardiopulmonary resuscitation (21 = 20.6% were discharged), 25.0% of the total number underwent emergency surgery, and 43% needed intensive care. A general admission unit for pure emergencies is still a unique organizational feature in hospitals. The main objective of the EAU is to increase patient's safety during transition from prehospital to primary hospital acute care. EAU anesthesia staff ensures the competency in acute care and even the continuity of care by the same person from the emergency ambulance to the operating room or ICU.

Admitting Department, Hospital↗

[Contraindications and termination of resuscitation].

The physician's task is to recognize the patient who is not going to benefit from the cardio-pulmonary resuscitation (CPR). He is obliged to decide whether the CPR should be initiated at all, or should it be terminated if already started. Two points are to be considered: the natural history of the present illness and the wish of the patient. Acting against those rules injures the patient's dignity and makes the unavoidable dying longer.

Austria↗

[Noninvasive monitoring using echocardiography. II. Determination of cardiac output and comparison of volatile anesthetics].

In order to prove definitely that echocardiography is a noninvasive and safe method that can be used in the perioperative period to assess cardiac function and evaluate the effects of pharmacologic agents on the heart, we have carried out further sonographic studies concerning cardiac output and the effects of volatile anesthetics on left ventricular contractility. In series A (n = 12), we compared different sonographic techniques (uni-dimensional, two-dimensional, pulse Doppler echocardiography) with invasively measuring cardiac output by thermodilution in ICU patients and in the immediate preoperative phase before CABG with a Swan Ganz catheter that was already inserted. M-mode echocardiography proved to be best and correlated well with invasively gained values (y = 0.57 + 0.96x, r = 0.795, p less than 0.01). Use of the Teichholtz formula to estimate left ventricle volumes seems to be imperative. The two-dimensional technique yielded less favorable results, the pulse Doppler method being least informative. In series B (n1 = n2 = n3 = 6) the effects of halothane, enflurane and isoflurane MAC 1.0 and 1.5 on left ventricular performance were assessed in patients undergoing cholecystectomy or gastrectomy under standard anesthetic conditions. The results support the already well-known pharmacologic effects of these drugs, with minimal decrease in contraction with isoflurane. Critical interpretation of the different sonographic parameters, however, is just as important as considering various existing interdependances. Finally, when comparing our numerical values with other 1.0 MAC effects reported in the literature, there was also very good agreement.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

[Noninvasive monitoring with echocardiography. I. Ventricular function following thiopental and positive pressure breathing].

Using continuous M-mode echocardiography for measuring diameters of the left ventricle and calculating variables of left ventricular contractility during induction of anaesthesia the hemodynamic effects of thiopentone and of positive end-expiratory pressure breathing (PEEP) have been noninvasively assessed in 22 patients undergoing minor surgery (series A, n = 4 + 6, thiopentone) or cholecystectomy (series B, n = 12, PEEP). 4 mg X kg-1 i.v. (group I, n = 4) and 2 X 4 mg X kg-1, the second dose injected i.v. 5 min later (group II, n = 6), led in group I to a short lasting and in group II to a prolonged (duration of each experiment 10 min) significant decrease of the ejection fraction (EF), the shortening fraction (FS) and the mean velocity of circumferential fiber shortening (VCF mean). Thus the well known negative inotropic effect of thiopentone has been proven once more this time by noninvasive echocardiography. The influence of PEEP 5 and 10 cm H2O was evaluated in two ways: 1) by finding the incidence and extent of diminishing the "echocardiographic window" due to overexpansion of the lung during PEEP, rendering the sonographic visualization of the cardiac structures less valid, and 2) by assessing potential haemodynamic effects of PEEP. The curves of 3 in 12 cases (25%) have not been able to be evaluated properly because of "window closing"; in the residual 9 patients during PEEP 10 a significant decrease of the above mentioned parameters of contractility in comparison to PEEP 0 has been observed. IPPB without PEEP apparently does not disturb echocardiographic visualization.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Substitution therapy with an antithrombin III concentrate in shock and DIC.

In 15 patients admitted to the Intensive Care Unit for shock and with signs of DIC, Antithrombin III (AT III) was substituted. Immediately after the first blood sampling, 1,000 units of AT III was given. This was followed by 500 units AT III after 24 h and after 48 h. A continuous dose of heparin of between 250 and 500 I.U./h was simultaneously given. The following results were obtained: The activity of AT III on admission of 63 +/- 19% increased to 83 +/- 17% 30 min after the initial substitution. There was a clear difference between the recovery of the substituted AT III in acute DIC and in patients in a steady state. AT III recovered in circulation was 47 +/- 15% in the former group but 83 +/- 16% in the latter cases. One unit of AT III per kg body weight increased AT III activity in circulation by 1% in acute DIC but by 1.8% in a steady state. The average half life of the substituted AT III was 4.4 +/- 1.6 h in acute DIC and was 20.2 +/- 4.1 h when the patients were in a steady state.

Adult↗

[Substitution of antithrombin III in shock patients].

In 15 patients admitted to the operative intensive care unit of the Institute of Anesthesiology for shock and with signs of DIC, antithrombin III (AT III) was substituted together with a continuous infusion of heparin. 1,000 units AT III were given after the first blood sampling. This was followed by 500 units after 24 h and after 48 h. 14 out of the 15 cases could be evaluated. The activity of AT III prior to substitution was below 75% in 10 cases and above 75% in 4 cases. The mean increase after substitution was 16%. The recovery was below 50% in cases with acute DIC whilst it was 90% in cases in a comparatively steady state. One unit AT III per kg body weight increased the activity of AT III in circulation by an average of 1% in acute DIC whilst the increase was 2% in cases without signs of acute DIC. The average half disappearance of the increase of AT III in circulation was 4.25 h in acute DIC but was 19.0 h when acute DIC was not detectable.

Adult↗

[General anesthesia in eye operations (author's transl)].

This retrospective study reports on ten years' experience of general anesthesia in ophthalmosurgery (4080 cases) at the General Hospital in Linz, Austria. The majority of patients in ophthalmosurgery are infants, children and geriatric patients confronting the anesthesiologist with specific problems. Anesthesiologic techniques and complications are discussed. Cooperation and continuous qualified anesthesiologic care are essential for good results. In bulb-opening procedures Valium-Neuroleptanalgesia is preferred, as it involves less stress, especially for the geriatric patient, and insures optimal operating conditions for the ophthalmologist. In the Linz General Hospital general anesthesia has become the method of choice in eye surgery.

Adolescent↗