Pressure- vs. volume-controlled ventilation and their respective impact on dynamic parameters of fluid responsiveness: a cross-over animal study.

BACKGROUND AND GOAL OF STUDY: Pulse pressure variation (PPV) and stroke volume variation (SVV), which are based on the forces caused by controlled mechanical ventilation, are commonly used to predict fluid responsiveness. When PPV and SVV were introduced into clinical practice, volume-controlled ventilation (VCV) with tidal volumes (VT) ≥ 10 ml kg- 1 was most commonly used. Nowadays, lower VT and the use of pressure-controlled ventilation (PCV) has widely become the preferred type of ventilation. Due to their specific flow characteristics, VCV and PCV result in different airway pressures at comparable tidal volumes. We hypothesised that higher inspiratory pressures would result in higher PPVs and aimed to determine the impact of VCV and PCV on PPV and SVV. METHODS: In this self-controlled animal study, sixteen anaesthetised, paralysed, and mechanically ventilated (goal: VT 8 ml kg- 1) pigs were instrumented with catheters for continuous arterial blood pressure measurement and transpulmonary thermodilution. At four different intravascular fluid states (IVFS; baseline, hypovolaemia, resuscitation I and II), ventilatory and hemodynamic data including PPV and SVV were assessed during VCV and PCV. Statistical analysis was performed using U-test and RM ANOVA on ranks as well as descriptive LDA and GEE analysis. RESULTS: Complete data sets were available of eight pigs. VT and respiratory rates were similar in both forms. Heart rate, central venous, systolic, diastolic, and mean arterial pressures were not different between VCV and PCV at any IVFS. Peak inspiratory pressure was significantly higher in VCV, while plateau, airway and transpulmonary driving pressures were significantly higher in PCV. However, these higher pressures did not result in different PPVs nor SVVs at any IVFS. CONCLUSION: VCV and PCV at similar tidal volumes and respiratory rates produced PPVs and SVVs without clinically meaningful differences in this experimental setting. Further research is needed to transfer these results to humans.

Differences in patterns of sexual assault among female victims preceding and during the COVID-19 pandemic: an analysis of encounters in an emergency department.

The aim of this study was to evaluate how the COVID-19 pandemic may have impacted the number and patterns of sexual assault victims within a German metropolitan city. A retrospective single center analysis of the gynecology examination reports of all women presenting to the emergency department of a university hospital after a sexual offense between 03/2013 and 02/2021 (n = 1167). Comparison of the first year of the pandemic 03/2000-03/2021) to previous years (03/2017-02/2020) and comparison of periods of government-imposed social distancing (03/12/2020-05/23/2020 and 10/23/2020-02/28/2021) with corresponding periods of pre-pandemic years. The overall number of sexual assault cases did not change during the first year of the COVID-19 pandemic. However, during the stay-at-home orders, the number of women presenting to the emergency department decreased by 38% (n=45 vs. 72). Fewer victims filed a police report during the pandemic (49.5% vs. 73.9%, p<0.001) and the lockdown period (50% vs. 76.5%, p<0.001). Less genital injuries after sexual assault were detected during the pandemic (14.3% vs. 25.2%, p<0.02), but there was an increase of illegal substance abuse (19.5% vs. 9.3%, p<0.003). During the stay-at-home orders fewer victims reported alcohol consumption (42.4% vs. 62.5 %, p<0.023). Despite the decrease in sexual offense related police reports, the number of sexual assault cases remained consistent, and the usage of illegal drugs increased during the COVID-19 pandemic. These findings represent the importance of providing support to sexual assault victims, as well as the implementation of preventative measures, especially in times of crisis.

The impact of Enhanced Recovery after Surgery (ERAS) pathways with regard to perioperative outcome in patients with ovarian cancer.

PURPOSE: Major surgery for ovarian cancer is associated with significant morbidity. Recently, guidelines for perioperative care in gynecologic oncology with a structured "Enhanced Recovery after Surgery (ERAS)" program were presented. Our aim was to evaluate if implementation of ERAS reduces postoperative complications in patients undergoing extensive cytoreductive surgery for ovarian cancer. METHODS: 134 patients with ovarian cancer (FIGO I-IV) were included. 47 patients were prospectively studied after implementation of a mandatory ERAS protocol (ERAS group) and compared to 87 patients that were treated before implementation (pre-ERAS group). Primary endpoints of this study were the effects of the ERAS protocol on postoperative complications and length of stay in hospital. RESULTS: Preoperative and surgical data were comparable in both groups. Only the POSSUM score was higher in the ERAS group (11.8% vs. 9.3%, p < 0.001), indicating a higher surgical risk in the ERAS group. Total number of postoperative complications (ERAS: 29.8% vs. pre-ERAS: 52.8%, p = 0.011), and length of hospital stay (ERAS: 11 (6-23) vs pre-ERAS: 13 (6-50) days; p < 0.001) differed significantly. A lower fraction of patients of the ERAS group (87.2%) needed postoperative admission to the ICU compared to the pre-ERAS group (97.7%), p = 0.022). Mortality within the ERAS group was 0% vs. 3.4% (p = 0.552) in the pre-ERAS group. CONCLUSION: The implementation of a mandatory ERAS protocol was associated with a lower rate of postoperative complications and a reduced length of stay in hospital. If ERAS has influence on long-term outcome needs to be further evaluated.

Improving hospital hygiene to reduce the impact of multidrug-resistant organisms in health care--a prospective controlled multicenter study.

BACKGROUND: Nosocomial infections are the most common complication during inpatient hospital care. An increasing proportion of these infections are caused by multidrug-resistant organisms (MDROs). This report describes an intervention study which was designed to address the practical problems encountered in trying to avoid and treat infections caused by MDROs. The aim of the HARMONIC (Harmonized Approach to avert Multidrug-resistant Organisms and Nosocomial Infections) study is to provide comprehensive support to hospitals in a defined study area in north-east Germany, to meet statutory requirements. To this end, a multimodal system of hygiene management was implemented in the participating hospitals. METHODS/DESIGN: HARMONIC is a controlled intervention study conducted in eight acute care hospitals in the 'Health Region Baltic Sea Coast' in Germany. The intervention measures include the provision of written recommendations on methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococci (VRE) and multi-resistant Gram-negative bacteria (MRGN), supplemented by regional recommendations for antibiotic prescriptions. In addition, there is theoretical and practical training of health care workers (HCWs) in the prevention and handling of MDROs, as well as targeted and critically gauged applications of antibiotics. The main outcomes of the implementation and analysis of the HARMONIC study are: (i) screening rates for MRSA, VRE and MRGN in high-risk patients, (ii) the frequency of MRSA decolonization, (iii) the level of knowledge of HCWs concerning MDROs, and (iv) specific types and amounts of antibiotics used. The data are predominantly obtained by paper-based questionnaires and documentation sheets. A computer-assisted workflow-based documentation system was developed in order to provide support to the participating facilities. The investigation includes three nested studies on risk profiles of MDROs, health-related quality of life, and cost analysis. A six-month follow-up study investigates the quality of life after discharge, the long-term costs of the treatment of infections caused by MDROs, and the sustainability of MRSA eradication. DISCUSSION: The aim of this study is to implement and evaluate an area-wide harmonized hygiene program to control the nosocomial spreading of MDROs. Comparability between the intervention and control group is ensured by matching the hospitals according to size (number of discharges per year/number of beds) and level of care (standard or maximum). The results of the study may provide important indications for the implementation of regional MDRO management programs.

Respiratory gating improves correlation between pulse wave transit time and pulmonary artery pressure in experimental pulmonary hypertension.

Objective. Since pulse wave transit time (PWTT) shortens as pulmonary artery pressure (PAP) increases it was suggested as a potential non-invasive surrogate for PAP. The state of tidal lung filling is also known to affect PWTT independently of PAP. The aim of this retrospective analysis was to test whether respiratory gating improved the correlation coefficient between PWTT and PAP.Approach. In each one of five anesthetized and mechanically ventilated pigs two high-fidelity pressure catheters were placed, one directly behind the pulmonary valve, and the second one in a distal branch of the pulmonary artery. PAP was raised using the thromboxane A2 analogue U46619 and animals were ventilated in a pressure controlled mode (I:E ratio 1:2, respiratory rate 12/min, tidal volume of 6 ml kg-1). All signals were recorded using the multi-channel platform PowerLab®. The arrival of the pulse wave at each catheter tip was determined using a MATLAB-based modified hyperbolic tangent algorithm and PWTT calculated as the time interval between these arrivals.Main results. Correlation coefficient for PWTT and mean PAP wasr= 0.932 for thromboxane. This correlation coefficient increased considerably when heart beats either at end-inspiration (r= 0.978) or at end-expiration (r= 0.985) were selected (=respiratory gating).Significance. The estimation of mean PAP from PWTT improved significantly when taking the respiratory cycle into account. Respiratory gating is suggested to improve for the estimation of PAP by PWTT.

Impact of Introducing a PACU24 Concept on the Perioperative Outcome of Patients with Advanced Ovarian Cancer Treated with Cytoreductive Surgery.

Introduction: Patients with ovarian cancer who undergo multivisceral surgery usually require intensive care monitoring postoperatively. In view of the ever-fewer numbers of high-care/intensive care beds and the introduction of fast-track treatment concepts, it is increasingly being suggested that these patients should be cared for postoperatively in 24-h Post Anesthesia Care Units (PACU24). No analyses have been carried out to date to investigate whether such a postoperative care concept might be associated with a potential increase in postoperative complications in this patient cohort. Methods: A PACU24 unit was set up in our institution in 2015 and it has become the primary postoperative care pathway for patients with ovarian cancer who have undergone cytoreductive (debulking) surgery. A structured, retrospective analysis of data from patients treated before (control group) and after (PACU group) the introduction of this care concept was carried out, with a particular focus on postoperative complications and secondary admission to an intensive care unit where necessary. Results: The data of 42 patients were analyzed for the PACU group and 45 patients for the control group. According to the analysis, the preoperative and surgical data of both groups were comparable (age, ASA, BMI, FIGO stage, duration of surgery, blood loss). The Physiological and Operative Severity Score for the enUmeration of Mortality and morbidity (POSSUM score) as a measure for the risk of postoperative complications was higher in the PACU group (11.1% vs. 9.7%, p = 0.001). Patients in the PACU group underwent bowel resection with anastomosis significantly more often (76.3% vs. 33.3%, p < 0.001), although the extent of surgery was otherwise comparable. The total number, type and severity of postoperative complications and the duration of the overall stay in hospital did not differ between the two groups. None of the patients required secondary transfer from the PACU or normal ward to an intensive care unit (ICU). Summary: Our data support the assumption that the care concept of transferring patients to a PACU24 represents a safe and cost-saving care pathway for the postoperative care of patients even after complex gynecological-oncological procedures.

Ventilation Induces Changes in Pulse Wave Transit Time in the Pulmonary Artery.

Pulse wave transit time (PWTT) shortens as pulmonary artery pressure (PAP) increases and was therefore suggested as a surrogate parameter for PAP. The aim of this analysis was to reveal patterns and potential mechanisms of ventilation-induced periodic changes in PWTT under resting conditions. To measure both PWTT and PAP in five healthy pigs, two pulmonary artery Mikro-Tip™ catheters were inserted into the pulmonary vasculature: one with the tip placed in the pulmonary artery trunk, and a second one placed in a distal segment of the pulmonary artery. Animals received pressure-controlled mechanical ventilation. Ventilation-dependent changes were seen in both variables, PWTT and mean PAP; however, changes in PWTT were not synchronous with changes in PAP. Thus, plotting the value of PWTT for each heartbeat over the respective PAP revealed a characteristic hysteresis. At the beginning of inspiration, PAP rose while PWTT remained constant. During further inspiration, PWTT started to decrease rapidly as mPAP was about to reach its plateau. The same time course was observed during expiration: while mPAP approached its minimum, PWTT increased rapidly. During apnea this hysteresis disappeared. Thus, non-synchronous ventilation-induced changes in PWTT and PAP were found with inspiration causing a significant shortening of PWTT. Therefore, it is suggested that the respiratory cycle should be considered when using PWTT as a surrogate for PAP.

Correlation of Pulse Wave Transit Time with Pulmonary Artery Pressure in a Porcine Model of Pulmonary Hypertension.

For the non-invasive assessment of pulmonary artery pressure (PAP), surrogates like pulse wave transit time (PWTT) have been proposed. The aim of this study was to invasively validate for which kind of PAP (systolic, mean, or diastolic) PWTT is the best surrogate parameter. To assess both PWTT and PAP in six healthy pigs, two pulmonary artery Mikro-Tip™ catheters were inserted into the pulmonary vasculature at a fixed distance: one in the pulmonary artery trunk, and a second one in a distal segment of the pulmonary artery. PAP was raised using the thromboxane A2 analogue U46619 (TXA) and by hypoxic vasoconstriction. There was a negative linear correlation between PWTT and systolic PAP (r = 0.742), mean PAP (r = 0.712) and diastolic PAP (r = 0.609) under TXA. During hypoxic vasoconstriction, the correlation coefficients for systolic, mean, and diastolic PAP were consistently higher than for TXA-induced pulmonary hypertension (r = 0.809, 0.778 and 0.734, respectively). Estimation of sPAP, mPAP, and dPAP using PWTT is feasible, nevertheless slightly better correlation coefficients were detected for sPAP compared to dPAP. In this study we establish the physiological basis for future methods to obtain PAP by non-invasively measured PWTT.

Transcriptome Analysis in Vulvar Squamous Cell Cancer.

To date, therapeutic strategies in vulvar squamous cell carcinoma (VSCC) are lacking molecular pathological information and targeted therapy hasn't been approved in the treatment of VSCC, yet. Two etiological pathways are widely accepted: HPV induced vs. HPV independent, associated with chronic skin disease, often harboring TP53 mutations (mut). The aim of this analysis was to analyze the RNA expression patterns for subtype stratification on VSCC samples that can be integrated into the previously performed whole exome sequencing data for the detection of prognostic markers and potential therapeutic targets. We performed multiplex gene expression analysis (NanoString) with 770 genes in 24 prior next generation sequenced samples. An integrative data analysis was performed. Here, 98 genes were differentially expressed in TP53mut vs. HPV+ VSCC, in the TP53mut cohort, where 56 genes were upregulated and 42 were downregulated in comparison to the HPV+ tumors. Aberrant expression was primarily observed in cell cycle regulation, especially in HPV+ disease. Within the TP53mut group, a distinct cluster was identified that was correlated to a significantly worse overall survival (p = 0.017). The RNA expression profiles showed distinct patterns with regard to the known VSCC subtypes and could potentially enable further subclassification in the TP53mut groups.