Correction: Jansa et al. Hospitalisation Is Prognostic of Survival in Chronic Thromboembolic Pulmonary Hypertension. J. Clin. Med. 2022, 11, 6189

Error in Figure [...].

Chemotherapy versus chemoradiotherapy in borderline resectable and locally advanced pancreatic adenocarcinoma

The role of radiotherapy in borderline resectable (BRPC) and locally advanced pancreatic carcinoma (LAPC) remains controversial. In our study, we retrospectively evaluated 48 patients with BRPC (14; 29.2%) and LAPC (34; 70. 8%) who underwent 6-8 cycles of induction mFOLFIRINOX chemotherapy alone (23; 47.9%) or 4-6 cycles of mFOLFIRINOX followed by hypofractionated radiotherapy (up to the total dose of 39.9 Gy in 15 fractions) (25; 52.1%). Survival parameters were evaluated using the Gehan-Breslow-Wilcoxon Test and compared by using the long-rank test. The addition of radiotherapy was not associated with better survival (16.9 months for chemotherapy only versus 15.9 months for the combined therapy; p=0.486), as well as for both subgroups (13.5 months vs. 18.3 months; p=0.679) and (20.7 months vs. 13.8 months; p=0.425) for BRPC and LAPC, respectively. A higher resection rate was seen in the BRPC group compared to the LAPC group (43% vs. 17.6%, respectively). Our study revealed a significantly higher rate of lung metastases in patients after the combination therapy compared to those treated by chemotherapy only (19% vs. 0%, respectively; p=0.045). Such a borderline result, however, prevents us from drawing clear conclusions about whether this is an artifact caused by the low number of patients or whether radiotherapy leads to a selection of stem cells with a predilection to the generalization to the lungs.

Statement of the Expert Discussion Panel of the 1st Expert Conference on Point‑of‑Care ultrasound

The document summarizes the statement of the expert discussion panel of the 1st Point- of-Care Ultrasonography, which took place on 14 November 2022 in Prague and which led to the foundation of the Czech Multidisciplinary Task Force Group for standards,education and research in Point-of-Care ultrasound (Czech POCUS group).

A word on the microbiome: considerations about the history, current state, and terminology of an emerging discipline

Since the beginning of the 21st century, a new discipline, microbiome science, has emerged as a key part of microbiology and related biomedical and ecological sciences. Microbiome science uses highly advanced molecular genetic and bioinformatic methods to study complex microbial communities. Unlike isolated microbes, microbial communities shaped by the environment, referred to as microbial consortia or microbiomes, follow their own laws that allow for significant functional specialization. The synthesis of multimethodology and multidisciplinary data enables microbiome science to move towards a holistic picture of the microbiome in an exceptionally effective way, but on the other hand, it burdens the field with terminological ambiguity of the key terms, which consequently need to be clearly codified in accordance with the international trends in the use of technical nomenclature. To this end, we present in our article the official position of the Czech Microbiome Society of the J. E. Purkyně Czech Medical Society on the use of appropriate Czech terms in both professional and general communication.

Selected severe „haematological“ syndromes in adult intensive care patients

Haemophagocytic syndrome, diffuse alveolar haemorrhage, catastrophic antiphospholipid syndrome and various types of thrombotic microangiopathies are rare conditions with significant morbidity and mortality. A common feature is late diagnosis, which can affect the success of treatment. The aim of this review article is to summarize the basic diagnostic and therapeutic steps of the present subpopulation of critically ill patients.

Hospitalisation Is Prognostic of Survival in Chronic Thromboembolic Pulmonary Hypertension

This analysis investigated the prognostic value of hospitalisation in chronic thromboembolic pulmonary hypertension (CTEPH) using data from the Czech Republic, wherein pulmonary endarterectomy (PEA) was the only targeted treatment option until 2015. Using a landmark method, this analysis quantified the association between a first CTEPH-related hospitalisation event occurring before 3-, 6-, 9-, and 12-month landmark timepoints and subsequent all-cause mortality in adult CTEPH patients diagnosed between 2003 and 2016 in the Czech Republic. Patients were stratified into operable and inoperable, according to PEA eligibility. CTEPH-related hospitalisations were defined as non-elective. Hospitalisations related to CTEPH diagnosis, PEA, balloon pulmonary angioplasty, or clinical trial participation were excluded. Of 436 patients who survived to ≥3 months post diagnosis, 309 were operable, and 127 were inoperable. Sex- and age-adjusted hazard ratios (HRs) showed CTEPH-related hospitalisation was a statistically significant prognostic indicator of mortality at 3, 9, and 12 months in inoperable patients, with an approximately 2-fold increased risk of death in the hospitalisation group (HRs [95% CI] ranging from 1.98 [1.06–3.70] to 2.17 [1.01–4.63]). There was also a trend of worse survival probabilities in the hospitalisation groups for operable patients, with the difference most pronounced at 3 months, with a 76% increased risk of death (adjusted HR [95% CI] 1.76 [1.15–2.68]). This first analysis on the prognostic value of CTEPH-related hospitalisations demonstrates that a first CTEPH-related hospitalisation is prognostic of mortality in CTEPH, particularly for inoperable patients. These patients may benefit from medical and/or interventional therapy.

Control Centre for Intensive Care as a Tool for Effective Coordination, Real-Time Monitoring, and Strategic Planning During the COVID-19 Pandemic

In the Czech Republic, the strategic data-based and organizational support for individual regions and for providers of acute care at the nationwide level is coordinated by the Ministry of Health. At the beginning of the COVID-19 pandemic, the country needed to very quickly implement a system for the monitoring, reporting, and overall management of hospital capacities. The aim of this viewpoint is to describe the purpose and basic functions of a web-based application named "Control Centre for Intensive Care," which was developed and made available to meet the needs of systematic online technical support for the management of intensive inpatient care across the Czech Republic during the first wave of the pandemic in spring 2020. Two tools of key importance are described in the context of national methodology: one module for regular online updates and overall monitoring of currently free capacities of intensive care in real time, and a second module for online entering and overall record-keeping of requirements on medications for COVID-19 patients. A total of 134 intensive care providers and 927 users from hospitals across all 14 regions of the Czech Republic were registered in the central Control Centre for Intensive Care database as of March 31, 2021. This web-based application enabled continuous monitoring and decision-making during the mass surge of critical care from autumn 2020 to spring 2021. The Control Center for Intensive Care has become an indispensable part of a set of online tools that are employed on a regular basis for crisis management at the time of the COVID-19 pandemic.

Epidemiology of chronic thromboembolic pulmonary hypertension (CTEPH) in the Czech Republic

This study investigated the epidemiology and survival outcomes of chronic thromboembolic pulmonary hypertension (CTEPH) in the Czech Republic, wherein pulmonary endarterectomy (PEA) surgery was the only targeted treatment option until 2015. This study included all consecutive adults newly diagnosed with CTEPH in the Czech Republic between 2003 and 2016. Incidence/prevalence rates were calculated using general population data extracted from the Institute of Health Information and Statistics of the Czech Republic. Kaplan–Meier estimates of survival from diagnosis until 2018 were calculated. Of a total of 453 patients observed, 236 (52.1%) underwent PEA (median time from diagnosis to PEA: 2.9 months) and 71 (34.1%) had residual pulmonary hypertension (PH) post‐PEA. CTEPH incidence rate (95% confidence interval [CI]) between 2006 and 2016 was 4.47 (4.05; 4.91) patients per million (ppm) per year, and the prevalence (95% CI) was 37.43 (33.46; 41.73) ppm in 2016. The rate of CTEPH‐related hospitalizations (95% CI) per 100 person‐years was 24.4 (22.1; 26.9) for operated patients and 34.2 (30.9; 37.7) for not‐operated patients. Median overall survival (95% CI) for all patients from CTEPH diagnosis was 11.2 (9.4; not reached) years. Five‐year survival probability (95% CI) was 95.3% (89.9; 97.9) for operated patients without residual PH, 86.3% (75.3; 92.7) for operated patients with residual PH and 61.2% (54.0; 67.6) for not‐operated patients. This study reported epidemiological estimates of CTEPH in the Czech Republic consistent with estimates from other national systematic registries; and indicates an unmet medical need in not‐operated patients and operated patients with residual PH.

Impact of cumulative fluid balance on the pharmacokinetics of extended infusion meropenem in critically ill patients with sepsis

Background

Meropenem dosing for septic critically patients is difficult due to pathophysiological changes associated with sepsis as well as supportive symptomatic therapies. A prospective single-center study assessed whether fluid retention alters meropenem pharmacokinetics and the achievement of the pharmacokinetic/pharmacodynamic (PK/PD) targets for efficacy.

Methods

Twenty-five septic ICU patients (19 m, 6f) aged 32–86 years with the mean APACHE II score of 20.2 (range 11–33), suffering mainly from perioperative intra-abdominal or respiratory infections and septic shock (n = 18), were investigated over three days after the start of extended 3-h i.v. infusions of meropenem q8h. Urinary creatinine clearance (CL_cr) and cumulative fluid balance (CFB) were measured daily. Plasma meropenem was measured, and Bayesian estimates of PK parameters were calculated.

Results

Eleven patients (9 with peritonitis) were classified as fluid overload (FO) based on a positive day 1 CFB of more than 10% body weight. Compared to NoFO patients (n = 14, 11 with pneumonia), the FO patients had a lower meropenem clearance (CL_me 8.5 ± 3.2 vs 11.5 ± 3.5 L/h), higher volume of distribution (V₁ 14.9 ± 3.5 vs 13.5 ± 4.1 L) and longer half-life (t_1/2 1.4 ± 0.63 vs 0.92 ± 0.54 h) (p < 0.05). Over three days, the CFB of the FO patients decreased (11.7 ± 3.3 vs 6.7 ± 4.3 L, p < 0.05) and the PK parameters reached the values comparable with NoFO patients (CL_me 12.4 ± 3.8 vs 11.5 ± 2.0 L/h, V₁ 13.7 ± 2.0 vs 14.0 ± 5.1 L, t_1/2 0.81 ± 0.23 vs 0.87 ± 0.40 h). The CL_cr and Cockroft–Gault CL_cr were stable in time and comparable. The correlation with CL_me was weak to moderate (CL_cr, day 3 CGCL_cr) or absent (day 1 and 2 CGCL_cr). Dosing with 2 g meropenem q8h ensured adequate concentrations to treat infections with sensitive pathogens (MIC 2 mg/L). The proportion of pre-dose concentrations exceeding the MIC 8 mg/L and the fraction time with a target-exceeding concentration were higher in the FO group (day 1–3 f C_min > MIC: 67 vs 27%, p < 0.001; day 1%f T > MIC: 79 ± 17 vs 58 ± 17, p < 0.05).

Conclusions

These findings emphasize the importance of TDM and a cautious approach to augmented maintenance dosing of meropenem to patients with FO infected with less susceptible pathogens, if guided by population covariate relationships between CL_me and creatinine clearance.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-021-03680-9.

Efficacy and safety of early target-controlled plasma volume replacement with a balanced gelatine solution versus a balanced electrolyte solution in patients with severe sepsis/septic shock: study protocol, design, and rationale of a prospective, randomized, controlled, double-blind, multicentric, international clinical trial : GENIUS-Gelatine use in ICU and sepsis

BACKGROUND

Sepsis is associated with capillary leakage and vasodilatation and leads to hypotension and tissue hypoperfusion. Early plasma volume replacement is required to achieve haemodynamic stability (HDS) and maintain adequate tissue oxygenation. The right choice of fluids to be used for plasma volume replacement (colloid or crystalloid solutions) is still a matter of debate, and large trials investigating the use of colloid solutions containing gelatine are missing. This study aims to investigate the efficacy and safety of plasma volume replacement using either a combined gelatine-crystalloid regime (1:1 ratio) or a pure crystalloid regime.

METHODS

This is a prospective, controlled, randomized, double-blind, international, multicentric phase IV study with two parallel groups that is planned to be conducted at European intensive care units (ICUs) in a population of patients with hypovolaemia in severe sepsis/septic shock. A total of 608 eligible patients will be randomly assigned to receive either a gelatine-crystalloid regime (Gelaspan® 4% and Sterofundin® ISO, B. Braun Melsungen AG, in a 1:1 ratio) or a pure crystalloid regime (Sterofundin® ISO) for plasma volume replacement. The primary outcome is defined as the time needed to achieve HDS. Plasma volume replacement will be target-controlled, i.e. fluids will only be administered to volume-responsive patients. Volume responsiveness will be assessed through passive leg raising or fluid challenges. The safety and efficacy of both regimens will be assessed daily for 28 days or until ICU discharge (whichever occurs first) as the secondary outcomes of this study. Follow-up visits/calls will be scheduled on day 28 and day 90.

DISCUSSION

This study aims to generate evidence regarding which regimen-a gelatine-crystalloid regimen or a pure crystalloid regimen-is more effective in achieving HDS in critically ill patients with hypovolaemia. Study participants in both groups will benefit from the increased safety of target-controlled plasma volume replacement, which prevents fluid administration to already haemodynamically stable patients and reduces the risk of harmful fluid overload.

TRIAL REGISTRATION

The European clinical trial database EudraCT 2015-000057-20 and the ClinicalTrials.gov Protocol Registration and Results System ClinicalTrials.gov NCT02715466 . Registered on 17 March 2016.

Rectal cancer - current treatment strategy and the tumor regression grade evaluation after neoadjuvant therapy in patients who underwent surgery at the I. Department of Surgery, General University Hospital in Prague between 2012 and 2016

INTRODUCTION

The article contains a summary of the issues of staging and therapy with an emphasis on the neoadjuvant treatment and associated tumor regression grade with the analysis of our own group of patients.

METHODS

Retrospective analysis of patients with rectal cancer who underwent a surgery at the 1st Department of Surgery - Thoratic, Abdominal and Injury Surgery; First Faculty of Medicine, Charles University in Prague and General University Hospital in Prague, Czech Republic, focusing on those who underwent neoadjuvant chemoradiotherapy and their pathologists evaluated tumor regression grade after the resection.

RESULTS

The group consists of 161 patients operated on between 2012 and 2016. 47 patients underwent neoadjuvant oncological treatment with further evaluation of the tumor regression grade by a pathologist, a scoring system according to Ryan was used. A complete pathological response was elicited in 10.4% of patients, no response in 35.4% of patients, and partial tumor regression in 54.2%.

CONCLUSION

Although there is a difference in our results compared to foreign publications, the proportion of patients remains comparable. Studies evaluating the advantages versus disadvantages of neoadjuvant therapy will certainly follow, and the question of the suitability of surgical treatment as the only curative solution is partially raised.

Optimizing clinical approaches to COVID-19 patients in primary care

There is insufficient evidence from medical studies for clinical approaches to patients with COVID-19 in primary care. Patients often urge the therapeutic use and preventive administration of various medicines, often controlled by studies insufficiently or completely unverified. The aim of the project, commissioned by the Committee of the Society of General Practice of the Czech Medical Association JEP, was to compensate for this deficiency by interdisciplinary consensus and thus provide general practitioners (GPs) with a basic support in accessing patients with COVID-19. Representatives of GPs identified the most common questionable diagnostic or therapeutic approaches and formulated 17 theses, taking into account their own experience, existing Czech and foreign professional recommendations. The RAND/UCLA Appropriateness Method, modified for the needs of pandemic situation, was chosen to seek consensus. Representatives of 7 medical specialties accepted the participation in the 20-member panel. The panel evaluated in 2 rounds, with the comments and opinions of others available to all panelists before the second round. The outcome of the evaluation was agreement on 10 theses addressing the administration of vitamin D, inhaled corticosteroids in patients with COPD and bronchial asthma, acetylsalicylic acid, indications for D-dimer levels examination, preventive administration of LMWH, importance of pulse oximetry, indication for emergency services, indication for antibiotics and rules for distant contact. The panel disagreed on 6 theses recommending the administration of ivermectin, isoprinosine, colchicine and corticosteroids in patients with COVID-19 in primary care. One thesis, taking into account the use of D-dimers in primary care was evaluated as uncertain. The most discussed theses, on which there was also no agreement, were outpatient administration of corticosteroids and the importance of elevation of D-dimers levels or their dynamic increase in a symptomatic patient with COVID-19 as an indication for referral to hospital. The results of the consensus identified topics that need to be further discussed and on which it is appropriate to focus further research.

Azithromycin added to hydroxychloroquine for patients admitted to intensive care due to coronavirus disease 2019 (COVID-19)-protocol of randomised controlled trial AZIQUINE-ICU

Background

Novel coronavirus SARS-CoV-2 is known to be susceptible in vitro to exposure to hydroxychloroquine and its effect has been found to be potentiated by azithromycin. We hypothesise that early administration of hydroxychloroquine alone or in combination with azithromycin can prevent respiratory deterioration in patients admitted to intensive care due to rapidly progressive COVID-19 infection.

Methods

Design: Prospective, multi-centre, double-blind, randomised, controlled trial (RCT). Participants: Adult (> 18 years) within 24 h of admission to the intensive care unit with proven or suspected COVID-19 infection, whether or not mechanically ventilated. Exclusion criteria include duration symptoms of febrile disease for ≥ 1 week, treatment limitations in place or moribund patients, allergy or intolerance of any study treatment, and pregnancy. Interventions: Patients will be randomised in 1:1:1 ratio to receive Hydroxychloroquine 800 mg orally in two doses followed by 400 mg daily in two doses and azithromycin 500 mg orally in one dose followed by 250 mg in one dose for a total of 5 days (HC-A group) or hydroxychloroquine + placebo (HC group) or placebo + placebo (C-group) in addition to the best standard of care, which may evolve during the trial period but will not differ between groups. Primary outcome is the composite percentage of patients alive and not on end-of-life pathway who are free of mechanical ventilation at day 14. Secondary outcomes: The percentage of patients who were prevented from needing intubation until day 14, ICU length of stay, and mortality (in hospital) at day 28 and 90.

Discussion

Although both investigational drugs are often administered off label to patients with severe COVID-19, at present, there is no data from RCTs on their safety and efficacy. In vitro and observational trial suggests their potential to limit viral replication and the damage to lungs as the most common reason for ICU admission. Therefore, patients most likely to benefit from the treatment are those with severe but early disease. This trial is designed and powered to investigate whether the treatment in this cohort of patients leads to improved clinical patient-centred outcomes, such as mechanical ventilation-free survival.

Trial registration

Clinical trials.gov: NCT04339816 (Registered on 9 April 2020, amended on 22 June 2020); Eudra CT number: 2020-001456-18 (Registered on 29 March 2020).

Complex Reporting of the COVID-19 Epidemic in the Czech Republic: Use of an Interactive Web-Based App in Practice

BACKGROUND

The beginning of the coronavirus disease (COVID-19) epidemic dates back to December 31, 2019, when the first cases were reported in the People's Republic of China. In the Czech Republic, the first three cases of infection with the novel coronavirus were confirmed on March 1, 2020. The joint effort of state authorities and researchers gave rise to a unique team, which combines methodical knowledge of real-world processes with the know-how needed for effective processing, analysis, and online visualization of data.

OBJECTIVE

Due to an urgent need for a tool that presents important reports based on valid data sources, a team of government experts and researchers focused on the design and development of a web app intended to provide a regularly updated overview of COVID-19 epidemiology in the Czech Republic to the general population.

METHODS

The cross-industry standard process for data mining model was chosen for the complex solution of analytical processing and visualization of data that provides validated information on the COVID-19 epidemic across the Czech Republic. Great emphasis was put on the understanding and a correct implementation of all six steps (business understanding, data understanding, data preparation, modelling, evaluation, and deployment) needed in the process, including the infrastructure of a nationwide information system; the methodological setting of communication channels between all involved stakeholders; and data collection, processing, analysis, validation, and visualization.

RESULTS

The web-based overview of the current spread of COVID-19 in the Czech Republic has been developed as an online platform providing a set of outputs in the form of tables, graphs, and maps intended for the general public. On March 12, 2020, the first version of the web portal, containing fourteen overviews divided into five topical sections, was released. The web portal's primary objective is to publish a well-arranged visualization and clear explanation of basic information consisting of the overall numbers of performed tests, confirmed cases of COVID-19, COVID-19-related deaths, the daily and cumulative overviews of people with a positive COVID-19 case, performed tests, location and country of infection of people with a positive COVID-19 case, hospitalizations of patients with COVID-19, and distribution of personal protective equipment.

CONCLUSIONS

The online interactive overview of the current spread of COVID-19 in the Czech Republic was launched on March 11, 2020, and has immediately become the primary communication channel employed by the health care sector to present the current situation regarding the COVID-19 epidemic. This complex reporting of the COVID-19 epidemic in the Czech Republic also shows an effective way to interconnect knowledge held by various specialists, such as regional and national methodology experts (who report positive cases of the disease on a daily basis), with knowledge held by developers of central registries, analysts, developers of web apps, and leaders in the health care sector.

Treatment of anastomotic leak after Ivor Lewis esophagectomy

INTRODUCTION

Anastomotic leak (AL) is one of the most serious surgical complications after esophagectomy. Endoscopic, radiological and surgical methods are used in the treatment of AL. The aim of this study was to retrospectively evaluate our therapeutic procedures and results of AL treatment after Ivor Lewis esophagectomy (ILE).

METHODS

Retrospective audit of all ILEs performed in the years 20052019. Evaluation of AL treatment results according to Esophagectomy Complication Consensus Group (ECCG) classification and according to the primary therapeutic procedure with a focus on the treatment with esophageal stent.

RESULTS

Out of 817 patients with ILE, AL was detected in 80 patients (9.8%): ECCG type I 33 (41%), type II 23 (29%) and type III 24 (30%) patients. Some 33 patients (41%) were treated conservatively. Esophageal stents were used in 39 patients (49%), of which 18 (23%) had concomitant percutaneous drainage and 17 (21%) were reoperated. Reoperation without a stent insertion was performed in 7 patients (9%). Esophageal diversion with cervical esophagostomy was performed in a total of 16 patients (20%). Esophageal stent treatment was successful in 24/39 patients (62%). Airway fistula occurred in 4 patients treated with stent (10%). Endoscopic vacuum therapy was successfully used in three patients after stent failure. Eight patients (10%) died as a result of AL. Mortality of AL type I, II and III was 0%, 4% and 29%.

CONCLUSION

Successful treatment of AL requires an individual and multidisciplinary approach. The primary effort should aim to preserve anastomosis using endoscopic and radiological methods. In case of insufficient clinical effect, we recommend not to hesitate with reoperation. If primary therapy fails, the life-saving procedure is a cervical esophagostomy.

The effect of general anaesthesia on gastric myoelectric activity in experimental pigs

Background

Surface electrogastrography (EGG) is a non-invasive method for clinical assessment of gastric myoelectrical activity. Different forms of general anaesthesia might have various effects on porcine EGG. The aim of this study was to evaluate the impact of different anaesthetic agents on EGG in experimental pigs.

Methods

Four 15-minute EGG intervals were recorded and analysed. A baseline EGG recording was started 20 minutes after intramuscular injection of ketamine and azaperone (periods A and B). Four different regimens of general anaesthesia followed immediately after the baseline EGG (5 pigs in each experimental group): thiopental, isoflurane, nitrous oxide and isoflurane plus nitrous oxide. EGG recordings followed for the next 30 minutes under general anaesthesia (periods C and D). The dominant frequencies of slow waves were compared between the baseline intervals A and B and periods C and D under general anaesthesia.

Results

The mean dominant frequency was within the normal range (2.3 – 3.5 cycles per minute) in all animals in all regimens. Thiopental general anaesthesia did not influence any change of the dominant frequency of slow waves. Nitrous oxide general anaesthesia increased the dominant frequency of slow waves in a statistically significant manner (baseline: 2.93 ± 0.53 and 3.01 ± 0.53; under general anaesthesia: 3.25 ± 0.34 and 3.29 ± 0.38 cycles per minute; p < 0.001, p = 0.003, p < 0.001, p < 0.001). Nitrous oxide together with isoflurane induced a statistically significant decrease of dominant frequency in the last 15-minute interval (2.66 ± 0.55 cycles per minute) compared to the baseline recording (2.81 ± 0.49; p = 0.030).

Conclusions

All changes of porcine gastric myoelectric activity assessed by the dominant frequency of slow waves during EGG remained within the normal range although some of them achieved statistical significance. Thus all tested agents used for general anaesthesia can be recommended in preclinical studies with porcine models focused on gastric myoelectric activity without any risk of compromising the results. Thiopental seems to be the most suitable as it did not cause any changes at all.

Mild hypothermia attenuates changes in respiratory system mechanics and modifies cytokine concentration in bronchoalveolar lavage fluid during low lung volume ventilation

Hypothermia was shown to attenuate ventilator-induced lung injury due to large tidal volumes. It is unclear if the protective effect of hypothermia is maintained under less injurious mechanical ventilation in animals without previous lung injury. Tracheostomized rats were randomly allocated to non-ventilated group (group C) or ventilated groups of normothermia (group N) and mild hypothermia (group H). After two hours of mechanical ventilation with inspiratory fraction of oxygen 1.0, respiratory rate 60 min(-1), tidal volume 10 ml x kg(-1), positive end-expiratory pressure (PEEP) 2 cm H2O or immediately after tracheostomy in non-ventilated animals inspiratory pressures were recorded, rats were sacrificed, pressure-volume (PV) curve of respiratory system constructed, bronchoalveolar lavage (BAL) fluid and aortic blood samples obtained. Group N animals exhibited a higher rise in peak inspiratory pressures in comparison to group H animals. Shift of the PV curve to right, higher total protein and interleukin-6 levels in BAL fluid were observed in normothermia animals in comparison with hypothermia animals and non-ventilated controls. Tumor necrosis factor-alpha was lower in the hypothermia group in comparison with normothermia and non-ventilated groups. Mild hypothermia attenuated changes in respiratory system mechanics and modified cytokine concentration in bronchoalveolar lavage fluid during low lung volume ventilation in animals without previous lung injury.

In situ assessment of the liver microcirculation in mechanically ventilated rats using sidestream dark-field imaging

Assessment of hepatic microcirculation by on-line visualization has been impossible for a long time. Sidestream dark-field (SDF) imaging is a relatively new method allowing direct visualization of both mucosal microcirculation and surface layers microcirculation of solid organs using hand-held probe for direct contact with target tissue. The aim of this study was to evaluate the feasibility of studying the rat hepatic microcirculation in situ by SDF imaging. The liver lobes were left in situ, and images were obtained using SDF imaging on the surface of the liver via upper midline laparotomy. Images were captured intermittently during 10-sec apnoea and recorded. The microvascular parameters were compared with previous validation studies. Clear high contrast SDF images were successfully obtained. Quantitative analysis revealed a mean FSD (functional sinusoidal density) of 402±15 cm/cm2, a sinusoidal diameter of 10.2±0.5 μm and postsinusoidal venular diameter of 33.9±13 μm. SDF imaging is a suitable noninvasive method for accurate quantification of the basic microcirculatory parameters of the liver in situ without a need to exteriorize the liver lobes. This method seems to be applicable in animal studies with possibility to use SDF imaging also intraoperatively, providing unique opportunity to study liver microcirculation during various experimental and clinical settings.

Noninvasive in vivo assessment of the skeletal muscle and small intestine serous surface microcirculation in rat: sidestream dark-field (SDF) imaging

The pathophysiology of microcirculation is intensively investigated to understand disease development at the microscopic level. Orthogonal polarization spectral (OPS) imaging and its successor sidestream dark-field (SDF) imaging are relatively new noninvasive optical techniques allowing direct visualization of microcirculation in both clinical and experimental studies. The goal of this experimental study was to describe basic microcirculatory parameters of skeletal muscle and ileal serous surface microcirculation in the rat using SDF imaging and to standardize the technical aspects of the protocol. Interindividual variability in functional capillary density (FCD) and small vessels (<25 microm in diameter) proportion was determined in anesthetized rats on the surface of quadriceps femoris (m. rectus femoris and m. vastus medialis) and serous surface of ileum. Special custom made flexible arm was used to fix the SDF probe minimizing the pressure movement artifacts. Clear high contrast images were analyzed off-line. The mean FCD obtained from the surface of skeletal muscle and ileal serous surface was 219 (213-225 cm/cm(2)) and 290 (282-298 cm/cm(2)) respectively. There was no statistically significant difference between rats in mean values of FCD obtained from the muscle (P = 0.273) in contrast to ileal serous surface, where such difference was statistically significant (P = 0.036). No statistically significant differences in small vessels percentage was detected on either the muscle surface (P = 0.739) or on ileal serous surface (P = 0.659). Our study has shown that interindividual variability of basic microcirculatory parameters in rat skeletal muscle and ileum is acceptable when using SDF imaging technique according to a highly standardized protocol and with appropriate fixation device. SDF imaging represents promising technology for experimental and clinical studies.