Zdenek Turek

Anesthesia and the microcirculation.

There is increasing evidence that the microcirculation and its regulation are severely compromised during many pathological conditions, such as hemorrhage, sepsis, or trauma. The effects of anesthetic agents on macrohemodynamics were investigated intensively in the last several decades. Research regarding modern anesthetics and anesthesia techniques has increased knowledge regarding the nonanesthetic effects of anesthetic agents, including those on organ perfusion and the microcirculation. Alterations in microvascular reactivity, nitric oxide pathways, and cytokine release are presumably the main mechanisms of anesthetic-induced tissue perfusion changes. This review summarizes current methods of microcirculatory status assessment and current knowledge regarding the microcirculatory effects of intravenous and potent volatile anesthetics and anesthesia-related techniques under both normal and pathophysiological conditions.

Suture-Free Anastomosis of the Colon Experimental Comparison of Two Cyanoacrylate Adhesives

BackgroundWe explored the potential of two cyanoacrylate tissue adhesives for constructing colonic anastomoses.MethodThe study involved 12 female domestic pigs. The animals were divided into two equal groups. In both groups, the sigmoid colon was transected. An intestinal anastomosis was constructed with a modified circular stapler (all staples were withdrawn) and cyanoacrylate tissue adhesives. Glubran 2® was used in group A and Dermabond® was applied in group B. Fourteen days after the first operation, a follow-up surgery was performed in both groups. The glued section of the colon was resected, processed with the standard paraffin technique and stained with haematoxylin–eosin. The finished specimens were examined under light microscopy. Assessments were made for the presence of fibroblasts, neutrophils, giant polynuclear cells, neovascularisation and collagen deposits. Adhesions, anastomotic dehiscence, peri-anastomotic inflammation and intestinal healing were assessed peri-operatively.ResultsAll anastomoses in group A healed with no signs of pathology. In group B, fibrotic adhesions and stenoses tended to occur in areas surrounding the anastomoses. Histological examinations confirmed increased fibrosis.ConclusionThe tissue adhesive Glubran 2 appears to be (under experimental conditions) a promising synthetic adhesive for colonic anastomosis construction; conversely, the tissue adhesive Dermabond was unsuitable for suture-free anastomosis construction.

Epidemiology of hospital-acquired pneumonia: Results of a Central European multicenter, prospective, observational study compared with data from the European region

BACKGROUND Hospital-acquired pneumonia (HAP) is associated with high mortality. In Central Europe, there is a dearth of information on the prevalence and treatment of HAP. This project was aimed at collecting multicenter epidemiological data on patients with HAP in the Czech Republic and comparing them with supraregional data. METHODS This prospective, multicenter, observational study processed data from a database supported by a Czech Ministry of Health grant project. Included were all consecutive patients aged 18 and over who were admitted to participating intensive care units (ICUs) between 1 May 2013 and 31 December 2014 and met the inclusion criterion of having HAP. The primary endpoint was to analyze the relationships between 30-day mortality (during the stay in or after discharge from ICUs) and the microbiological etiological agent and adequacy of initial empirical antibiotic therapy in HAP patients. RESULTS The group dataset contained data on 330 enrolled patients. The final validated dataset involved 214 patients, 168 males (78.5%) and 46 females (21.5%), from whom 278 valid lower airway samples were obtained. The mean patient age was 59.9 years. The mean APACHE II score at admission was 21. Community-acquired pneumonia was identified in 13 patients and HAP in 201 patients, of whom 26 (12.1%) had early-onset and 175 (81.8%) had late-onset HAP. Twenty-two bacterial species were identified as etiologic agents but only six of them exceeded a frequency of detection of 5% (Klebsiella pneumoniae 20.4%, Pseudomonas aeruginosa 20.0%, Escherichia coli 10.8%, Enterobacter spp. 8.1%, Staphylococcus aureus 6.2% and Burkholderia cepacia complex 5.8%). Patients infected with Staphylococcus aureus had significantly higher rates of early-onset HAP than those with other etiologic agents. The overall 30-day mortality rate for HAP was 29.9%, with 19.2% mortality for early-onset HAP and 31.4% mortality for late-onset HAP. Patients with late-onset HAP receiving adequate initial empirical antibiotic therapy had statistically significantly lower 30-day mortality than those receiving inadequate initial antibiotic therapy (23.8% vs 42.9%). Patients with ventilator-associated pneumonia (VAP) had significantly higher mortality than those who developed HAP with no association with mechanical ventilation (34.6% vs 12.7%). Patients having VAP treated with adequate initial antibiotic therapy had lower 30-day mortality than those receiving inadequate therapy (27.2% vs 44.8%). CONCLUSIONS The present study was the first to collect multicenter data on the epidemiology of HAP in the Central European Region, with respect to the incidence of etiologic agents causing HAP. It was concerned with relationships between 30-day patient mortality and the type of HAP, etiologic agent and adequacy of initial empirical antibiotic therapy.

Differential effects of intravenous anesthetics on hepatosplanchnic microcirculation in rats: sidestream dark-field imaging study.

This study aimed to investigate the effects of intravenous anesthetics on hepatosplanchnic microcirculation in laparotomized mechanically ventilated rats using Sidestream Dark-field (SDF) imaging. Thirty male Wistar rats were divided into 5 groups (n = 6 each). All rats were initially anesthetized with 60 mg/kg pentobarbital (i.p.) for instrumentation. This was followed by either ketamine, propofol, thiopental, midazolam or saline+fentanyl (iv bolus over 5 min and then maintenance over 90 min). SDF imaging of the liver and distal ileum microcirculation was performed at the baseline and at t = 5, 35, 65 and 95 min. In propofol group there was increase of functional sinusoidal density (FSD) following induction (+25%, P < 0.05) and maintenance at t = 95 min (+10.3%, P < 0.05), in ketamine and midazolam group decrease of FSD was observed after induction (-20.4%, P < 0.05; -10.1%, P < 0.05) and during maintenance at t = 65 min (-11.6%, P < 0.05; -11.4%, P < 0.05) when compared to baseline. Following induction with propofol functional capillary density (FCD) of ileal longitudinal muscle layer increased (+10.6%, P < 0.05) and returned to baseline values during maintenance. Ketamine and midazolam decreased FCD of longitudinal layer after induction (-24.6%, P < 0.05; -21.1%, P < 0.05) and remained decreased during maintenance at t = 95 min (-10.8%, P < 0.05; -15.5%, P < 0.05). In thiopental and control group, changes in microcirculatory parameters were not significant throughout the study. In conclusion, intravenous anesthetics affect the hepatosplanchnic microcirculation differentially, propofol has shown protective effect on the liver and intestinal microcirculation.

Preserved cerebral microcirculation in early stages of endotoxemia in mechanically-ventilated rabbits

The purpose of our study was to evaluate changes of the cerebral microcirculation during the early stages of endotoxemia in mechanically-ventilated rabbits using Sidestream dark-field (SDF) imaging. Images were obtained using SDF imaging from the surface of the brain via craniotomy before and after rapid administration of a high dose of endotoxin or saline (control group). Although endotoxin shock was successfully induced, we have not found any significant alteration of the cerebral microcirculation during the shock. We speculate that either the model of sepsis with a rapid high dose of endotoxin does not reflect the usual progression of septic encephalopathy or some components other than cerebral microcirculatory alteration play a role at the early stage of septic encephalopathy and the cerebral microcirculation is still preserved. Further studies are needed to clarify our findings.

Comparison of cold crystalloid and colloid infusions for induction of therapeutic hypothermia in a porcine model of cardiac arrest

IntroductionLarge-volume cold intravenous infusion of crystalloids has been used for induction of therapeutic hypothermia after cardiac arrest. However, the effectiveness of cold colloids has not been evaluated. Therefore, we performed an experimental study to investigate the cooling effect of cold normal saline compared to colloid solution in a porcine model of ventricular fibrillation.MethodsVentricular fibrillation was induced for 15 minutes in 22 anesthetized domestic pigs. After spontaneous circulation was restored, the animals were randomized to receive either 45 ml/kg of 1°C cold normal saline (Group A, 9 animals); or 45 ml/kg of 1°C cold colloid solution (Voluven®, 6% hydroxyethyl starch 130/0.4 in 0.9% NaCl) during 20 minutes (Group B, 9 animals); or to undergo no cooling intervention (Group C, 4 animals). Then, the animals were observed for 90 minutes. Cerebral, rectal, intramuscular, pulmonary artery, and subcutaneous fat body temperatures (BT) were recorded. In the mechanical ex-vivo sub study we added a same amount of cold normal saline or colloid into the bath of normal saline and calculated the area under the curve (AUC) for induced temperature changes.ResultsAnimals treated with cold fluids achieved a significant decrease of BT at all measurement sites, whereas there was a consistent significant spontaneous increase in group C. At the time of completion of infusion, greater decrease in pulmonary artery BT and cerebral BT in group A compared to group B was detected (−2.1 ± 0.3 vs. -1.6 ± 0.2°C, and −1.7 ± 0.4 vs. -1.1 ± 0.3°C, p < 0.05, respectively). AUC analysis of the decrease of cerebral BT revealed a more vigorous cooling effect in group A compared to group B (−91 ± 22 vs. -68 ± 23°C/min, p = 0.046). In the mechanical sub study, AUC analysis of the induced temperature decrease of cooled solution revealed that addition of normal saline led to more intense cooling than colloid solution (−7155 ± 647 vs. -5733 ± 636°C/min, p = 0.008).ConclusionsIntravenous infusion of cold normal saline resulted in more intense decrease of cerebral and pulmonary artery BT than colloid infusion in this porcine model of cardiac arrest. This difference is at least partially related to the various specific heat capacities of the coolants.

Prolonged hypervolemic hemodilution decreases functional capillary density of ileal mucosa in pigs revealed by sidestream dark-field imaging

ObjectiveHemodilution changes the physical properties of blood by reducing its hematocrit and blood viscosity. We tested whether prolonged hypervolemic hemodilution (HHD) impairs functional capillary density (FCD) of ileal mucosa in healthy mechanically-ventilated pigs and if there is any correlation between changes in FCD of ileal and sublingual mucosas during HHD.MethodsSixteen domestic female pigs were anesthetized, mechanically-ventilated, and randomly assigned to the HHD (20 ml/(kg·h) Hartmann’s solution for 3 h) or fluid restrictive (5 ml/(kg·h) Hartmann’s solution for 3 h) group. Microcirculations of sublingual and ileal mucosas via ileostomy were visualized using sidestream dark-field (SDF) imaging at baseline conditions (t=0 h) and at selected time intervals of fluid therapy (t=1, 2, and 3 h).ResultsA significant decrease of ileal FCD (285 (278–292) cm/cm2) in the HHD group was observed after the third hour of HHD when compared to the baseline (360 (350–370) cm/cm2) (P<0.01). This trend was not observed in the restrictive group, where the ileal mucosa FCD was significantly higher after the third hour of fluid therapy as compared to the HHD group (P<0.01). No correlation between microhemodynamic parameters obtained from sublingual and ileal mucosas was found throughout the study.ConclusionsProlonged HHD established by crystalloid solution significantly decreased ileal villus FCD when compared to restrictive fluid regimen. An inappropriate degree of HHD can be harmful during uncomplicated abdominal surgery.

Assessment of regional ventilation with the electrical impedance tomography in a patient after asphyxial cardiac arrest.

Survival from cardiac arrest presenting initially with asystole r pulseless electrical activity is very unlikely unless all relevant eversible causes are recognized and treated effectively.1 In some atients, extensive differential diagnosis is needed to ascertain he cause of cardiac arrest, especially if differentiation between ardiovascular and respiratory aetiology is necessary. Routine iniial evaluation, including chest X-ray may not be sufficient to iagnose alterations in distribution of ventilation that may be resent in some respiratory disorders. Although examination with hest ultrasound could assess lung and pleural cavity pathologies,2 his technique requires expertise and does not directly quantify egional ventilation, while the benefits of computed tomography CT) should always be weighted to the risks and disadvantages f patient’s intra-hospital transportation. Use of a non-invasive ethod, an electrical impedance tomography (EIT), which has lready been used for assessment of lung volumes and distribution f ventilation under various clinical conditions,3,4 has not become ommon in post-resuscitation care. We report the case of a 61-year-old man admitted after sucessful resuscitation from asystolic out-of-hospital cardiac arrest OHCA) following a short period of severe dyspnoea. His per-

Surgical treatment of postinfarction ventricular septal defect: risk factors and outcome analysis

OBJECTIVES Postinfarction ventricular septal defect is a serious mechanical complication of acute myocardial infarction associated with high postoperative mortality. The aim of this study was to review our experience with surgical repair of postinfarction ventricular septal defect and to identify predictors of early and late outcomes. METHODS Thirty-nine patients (19 men and 20 women, mean age 68.4 ± 9.9 years) with postinfarction ventricular septal defect who underwent surgical repair at our institution between 1996 and 2016 were retrospectively evaluated. Risk factors were assessed by univariate analysis, with those found significant included in multivariate analysis. RESULTS The ventricular septal defect was anterior in 21 (54%) patients and posterior in 18 (46%) patients. Mean aortic cross-clamp time was 91.8 ± 26.8 min, and mean cardiopulmonary bypass time was 146.3 ± 49.7 min. Twelve (31%) patients underwent concomitant coronary artery bypass grafting. The 30-day mortality rate was 36% (n = 14). The 30-day survival rate was higher with than without concomitant coronary artery bypass grafting (83% vs 56%), but concomitant coronary artery bypass grafting did not influence late survival (P = 0.098). Univariate analysis identified age, emergency surgery, inotropic support, Killip class, preoperative aspartate aminotransferase concentration, renal replacement therapy and ventricular septal defect diagnosis to operation interval as predictors of 30-day mortality. However, multivariate analysis showed that age and renal replacement therapy were the only independent risk factors of 30-day mortality. CONCLUSIONS Surgical repair of postinfarction ventricular septal defect has a high 30-day mortality rate. Higher age at presentation and postoperative renal replacement therapy are independent predictors of early mortality.

Single-Center Experience with Minimally Invasive Mitral Operations through Right Minithoracotomy

Background: To report single-institution experience with minimally invasive mitral valve operations through the right minithoracotomy over a 5-year period. Methods: Patients who underwent minimally invasive mitral valve surgery (MIMVS) between January 2012 and December 2016 were included. Clinical follow-up data were collected in a prospective database and analyzed retrospectively. Results: Data from 151 patients were assessed (mean age, 63.4 ± 9.7 years; 55% were females). Overall 30-day mortality was 0.7% (n = 1). Mean operating time, cardiopulmonary bypass, and aortic cross-clamp times were 254.9 ± 48.7, 140.5 ± 36.1, and 94.8 ± 27.0 minutes, respectively. Associated procedures were tricuspid valve annuloplasty (37.1%, n = 56) and closure of atrial septal defect (6.0%, n = 9). Cryoablation was performed in 43.7% of patients (n = 66). One patient (0.7%) required conversion to median sternotomy and six patients (4.0%) underwent re-explorations due to bleeding. Median postoperative hospital stay was 12 days. Overall survival at 5 years was 94.1% ± 2.0%. Freedom from reoperation was 94.6% ± 2.9% at 5 years. Conclusions: MIMVS is a feasible, safe, and reproducible approach with low mortality and morbidity. Mitral valve surgery through a small thoracotomy is a good alternative to conventional surgical access.