Management of acute appendicitis during COVID-19 pandemic. Single center data from a tertiary care hospital in Germany.

Objectives: The unexpected global overload of the health system during COVID-19 pandemic has caused changes in management of acute appendicitis worldwide. Whereas conservative treatment was widely recommended, the appendicectomy remained standard therapy in Germany. We aimed to investigate the impact of COVID-19 pandemic on treatment routine for acute appendicitis at University Hospital of Magdeburg. Methods: Adult patients with clinical and/or radiological diagnosis of acute appendicitis were included in the single center retrospective study. Data was collected to patient demographics, treatment modality and outcomes including morbidity and length of stay. The patient data related to COVID-19 period from March 22, 2020 to December 31, 2021 (649 days) were compared to the Non-COVID-19 period from June 12, 2018 to March 21, 2020 (649 days). Subgroup analysis related to conservative or surgical treatment has been performed. Results: A total of 385 patients was included in the study, 203 (52.73 %) during Non-COVID-19 period and 182 (47.27 %) during COVID-19 period. Mean age of entire collective was 43.28 years, containing 43.9 % female patients (p=0.095). Conservative treatment was accomplished in 49 patients (12.7 % of entire collective), increasing from 9.9 % to 15.9 % during COVID-19 period (p=0.074). Laparoscopic appendicectomy was performed in 99.3 % (n=152) of operated patients during COVID-19 period (p=0.013), followed by less postoperative complications compared to reference period (23.5 % vs. 13.1 %, p=0.015). The initiation of antibiotic therapy after the diagnosis increased from 37.9 % to 53.3 % (p=0.002) during COVID-19 period regardless the following treatment modality. Antibiotic treatment showed shorter duration during pandemic period (5.57 days vs. 3.16 days, p<0.001) and it was given longer in the conservative treatment group (5.63 days vs. 4.26 days, p=0.02). The overall length of stay was shorter during COVID-19 period (4.67 days vs. 4.12 days, p=0.052) and in the conservative treatment group (3.08 days vs. 4.47 days, p<0.001). However, the overall morbidity was lower during the COVID-19 period than before (17.2 % vs. 7.7 %, p=0.005) and for conservative therapy compared to appendicectomy (2 % vs. 14.3 %, p=0.016). There was no mortality documented. Conclusions: According to our findings the COVID-19 pandemic had a relevant impact on treatment of acute appendicitis, but it was possible to maintain the traditional diagnostic and treatment pathway. Although laparoscopic appendicectomy remains a recommended procedure, the conservative treatment of uncomplicated appendicitis with excellent short-term outcome can be a safe alternative to surgery during potential new wave of COVID-19 pandemic and in the daily routine.

Tigecycline as salvage treatment of febrile neutropenia in patients with haematological malignancies-a retrospective single-centre analysis of 200 cases.

Tigecycline has been used to treat patients with febrile neutropenia (FN). This study aims to analyse the effectiveness of tigecycline as salvage treatment of FN. Patients records from 09/2004 to 04/2019 were reviewed. Cases were eligible if fever persisted/recurred (p/r-FN) after 3 days of second-line treatment with a carbapenem, and were divided into three groups: switch to tigecycline (TGC group), switch to other antibiotics (OAB group), and no switch (W&W group). The primary endpoint was response rate (defervescence for ≥ 7 days or at least until discharge); the key secondary endpoint was 30-day mortality rate. Two hundred cases from 176 patients (median 59 years; 53.5% men) treated were included, mostly acute myeloid leukaemias (61.0%). 45.5% of cases were in the TGC group (in combination with an anti-pseudomonal antibiotic, mostly ceftazidime [95.6%]); 35.5% were in the OAB and 19.0% in the W&W group. There was no significant difference in response rates (TGC, 73.6%; OAB, 62.0%; W&W, 78.9%; p = 0.12) or 30-day mortality rates (TGC, 7.7%; OAB, 7.0%; W&W, 5.3%; p = 0.94). Tigecycline plus an anti-pseudomonal antibiotic does not improve response or 30-day mortality rate compared to other antibiotics in patients with p/r-FN. Also, in some cases, no switch in antibiotics may be necessary at all.

Previous antibiotic therapy as independent risk factor for the presence of vancomycin-resistant enterococci in surgical inpatients. Results from a matched case-control study.

BACKGROUND: Investigation of risk factors for the presence of vancomycin-resistant enterococci (VRE) in inpatients on surgical wards and associated intensive care units of a German tertiary care hospital. METHODS: A single-centre retrospective matched case-control study was performed with surgical inpatients admitted between July 2013 and December 2016. Patients with in-hospital detection of VRE later than 48 h after admission were included and comprised 116 VRE-positive cases and 116 VRE-negative matched controls. VRE isolates of cases were typed by multi-locus sequence typing. RESULTS: ST117 was identified as the dominant VRE sequence type. Next to length of stay in hospital or on an intensive care unit and previous dialysis the case-control study revealed previous antibiotic therapy as a risk factor for the in-hospital detection of VRE. The antibiotics piperacillin/tazobactam, meropenem, and vancomycin were associated with the highest risks. After taking into account length of stay in hospital as possible confounder other potential contact-related risk factors such as previous sonography, radiology, central venous catheter, and endoscopy were not significant. CONCLUSIONS: Previous dialysis and previous antibiotic therapy were identified as independent risk factors for the presence of VRE in surgical inpatients.

The Need of Antimicrobial Stewardship in Post-Operative Infectious Complications of Abdominal Surgery.

Background: Post-operative infection is a common complication following abdominal surgery. The two most common infections are secondary peritonitis and surgical site infections, which lead to increased perioperative morbidity, prolonged hospitalization, higher mortality rates, and increased treatment costs. In addition to surgical procedures, treatment is based on effective antibiotic therapy. Due to increasing antimicrobial resistance, the correct use of antimicrobials is becoming more complex. Many initiatives call for the implementation of an antimicrobial stewardship (AMS) programme to optimize anti-infective therapy. The review article summarizes current recommendations in anti-infective therapy of post-operative peritonitis and surgical site infections and highlights the importance of an AMS programme in abdominal surgery. Summary: Larger studies evaluating the benefit of AMS in abdominal surgery are lacking. However, national and international guidelines have formulated appropriate recommendations for the rational use of antibiotics in post-operative peritonitis and surgical site infections. The rate of post-operative infections can be significantly reduced by perioperative antibiotic prophylaxis. The increase in multidrug-resistant bacteria complicates anti-infective therapy for post-operative infections. Analysis of local susceptibility patterns helps choose an adequate empiric therapy. A high rate of extended-spectrum beta-lactamase-producing bacteria may necessitate the use of other reserve antibiotics in addition to carbapenems, which are approved for the treatment of complicated intra-abdominal infections. A key role for the AMS team is the subsequent de-escalation of antibiotic therapy which limits the use of unnecessary broad-spectrum antibiotics. Key Messages: The increase in multidrug-resistant bacteria poses challenges for abdominal surgery. Post-operative infections should be treated by an interdisciplinary team of surgeons and specialists for AMS.

Normoxic post-ROSC ventilation delays hippocampal CA1 neurodegeneration in a rat cardiac arrest model, but does not prevent it.

The European Resuscitation Guidelines recommend that survivors of cardiac arrest (CA) be resuscitated with 100% O2 and undergo subsequent-post-return of spontaneous circulation (ROSC)-reduction of O2 supply to prevent hyperoxia. Hyperoxia produces a "second neurotoxic hit," which, together with the initial ischemic insult, causes ischemia-reperfusion injury. However, heterogeneous results from animal studies suggest that normoxia can also be detrimental. One clear reason for these inconsistent results is the considerable heterogeneity of the models used. In this study, the histological outcome of the hippocampal CA1 region following resuscitation with 100% O2 combined with different post-ROSC ventilation regimes (21%, 50%, and 100% O2) was investigated in a rat CA/resuscitation model with survival times of 7 and 21 days. Immunohistochemical stainings of NeuN, MAP2, GFAP, and IBA1 revealed a neuroprotective potency of post-ROSC ventilation with 21% O2, although it was only temporary. This limitation should be because of the post-ROSC intervention targeting only processes of ischemia-induced secondary injury. There were no ventilation-dependent effects on either microglial activation, reduction of which is accepted as being neuroprotective, or astroglial activation, which is accepted as being able to enhance neurons' resistance to ischemia/reperfusion injury. Furthermore, our findings verify the limited comparability of animal studies because of the individual heterogeneity of the animals, experimental regimes, and evaluation procedures used.

Relative Resilience of Cerebellar Purkinje Cells in a Cardiac Arrest/Resuscitation Rat Model.

BACKGROUND: In studies on cardiac arrest (CA)/resuscitation (R) injury, Purkinje cell degeneration was described, however, with inconsistent data concerning severity and time point of manifestation. Moreover, CA/R studies paid only limited attention to inhibitory stellate interneurons. To this aim, the hypothesis that cerebellar could be relatively resilient toward CA/R because of diverse cellular defense mechanisms including interaction with stellate cells was tested. METHODS: We examined rats with survival times of 6, 24, and 48 h, and 7 and 21 days in comparison with sham- and nonoperated animals. Thereby, we focused on the immunohistochemical expression of cfos, MnSOD, Bcl2, caspase 3, parvalbumin, calbindin D28 k, MAP2, IBA1, and GFAP, especially in the particular sensitivity to CA/R cerebellar lobule IX. Hippocampal CA1 degeneration was demonstrated by expression patterns of MAP2 and NeuN in combination with IBA1 and GFAP. RESULTS/CONCLUSIONS: Comparative analysis of hippocampal CA1 pyramidal cells and cerebellar Purkinje cells confirmed a relative resil-ience of Purkinje cells to CA/R. We found only a notable degeneration of Purkinje cell neuronal fiber network, which, however, not necessarily led to neuronal cell death. To induce significant Purkinje cell loss, a stronger ischemic trigger seems to be needed. As possible Purkinje cell-protecting mechanisms, we would propose: (1) activation of inhibitory stellate cells, shown by cfos, MnSOD, and Bcl2 expression, balancing out ischemia-induced excitation and inhibition of Purkinje cells; (2) translocation of the calcium-buffering system, shown by parvalbumin and calbindin D28 k expression, protecting Purkinje cells from detrimental calcium overload; (3) activation of the neuron-astrocyte cross talk, protecting Purkinje cells from over-excitation by removing potassium and neurotransmitters from the extracellular space; (4) activation of the effective and long-lasting MnSOD defense system; and (5) of the anti-apoptotic protein Bcl2 in Purkinje cells itself. Moreover, the results emphasize the limited comparability of animal CA/R studies because of the heterogeneity of the used experimental regimes.

Gynostemma pentaphyllum is neuroprotective in a rat model of cardiopulmonary resuscitation.

Asphyxial cardiac arrest (ACA)-induced ischemia results in acute and delayed neuronal cell death. The early reperfusion phase is critical for the outcome. Intervention strategies directed to this period are promising to reduce ACA/resuscitation-dependent impairments. This study focused on the evaluation of the protective potential of an extract from Gynostemma pentaphyllum (GP), a plant used in traditional medicine with antioxidative, glucose lowering and neuroprotective activities, in an ACA rat model. We tested the following parameters: i) Basic systemic parameters such as pCO2 and blood glucose value within the first 30 min post-ACA; ii) mitochondrial response by determining activities of citrate synthase, respiratory chain complexes I + III and II + III, and the composition of cardiolipin 6 and 24 h post-ACA; iii) neuronal vitality of the CA1 hippocampal region by immunohistochemistry 24 h and 7 days post-ACA; and iv) cognitive function by a novel object recognition test 7 days post-ACA. GP, administered after reaching spontaneous circulation, counteracted the following: i) ACA-mediated increases in arterial CO2 tension and blood glucose values; ii) transient increase in the activity of the respiratory chain complexes II + III; iii) elevation in cardiolipin content; iv) hippocampal CA1 neurodegeneration, and v) loss of normal novelty-object seeking. The protective effects of GP were accompanied by side effects of the vehicle DMSO, such as the stimulation of citrate synthase activity in control animals, inhibition of cardiolipin synthesis in ACA animals and complex II + III activity in both control and ACA animals. The results emphasize the importance of the early post-resuscitation phase for the neurological outcome after ACA/resuscitation, and demonstrated the power of GP substitution as neuroprotective intervention. Moreover, the results underline the need of a careful handling of the popular vehicle DMSO.

High-potential defense mechanisms of neocortex in a rat model of transient asphyxia induced cardiac arrest.

Cardiac arrest (CA) is a common cause of disability and mortality and thus an important risk for human health. Circulatory failure has dramatic consequences for the brain as one of the most oxygen-consuming organs. Hippocampus, striatum and neocortex rate among the most vulnerable brain regions. The neocortex is less sensitive to hypoxia/reperfusion in comparison with the hippocampal CA1 region. That implicates the existence of efficient defense mechanisms in the neocortex against hypoxia/reperfusion injury, which we analyzed in a well-established CA rat model. We explored different immunohistochemical markers (NeuN, MAP2, GFAP, IBA1, NOX4, MnSOD, Bax, caspase 3, cfos, nNOS, eNOS, iNOS, TUNEL), amount of mitochondria, activities of respiratory chain complexes and amount/composition of cardiolipin. CA induced a moderate degeneration of cortical neurons. As possible defense mechanisms the study revealed: (i) increased activities of respiratory chain complexes of cortical mitochondria as response to increased energy demand after ACA-induced cell stress; (ii) increase of cardiolipin content as cellular stress response, which might contribute to the promotion of mitochondrial ATP synthesis; (iii) strengthening of the fast, effective and long-lasting mitochondrial MnSOD defense system; (iv) ACA-induced increase in expression of eNOS and nNOS in vasculature being able to reduce ischemic injury by vasodilation.

Anesthesia specific differences in a cardio-pulmonary resuscitation rat model; halothane versus sevoflurane.

OBJECTIVE: Our asphyxia cardiac arrest (ACA) rat model is well established. The original model was designed in the 1990th using halothane and nitrous oxide for pre-insult anesthesia. Because of its hepato-toxicity and its potential to induce severe liver failures, halothane is no longer used in clinical anesthesia for several years. In order to minimize the health risk for our laboratory staff as well as to keep the experimental settings of our model on a clinically oriented basis we decided to replace halothane by sevoflurane. In this study we intended to determine if the change of the narcotic gas regiment causes changes in the neurological damage and how far our model had to be adjusted. METHODS: Adult rats were subjected to 5min of ACA followed by resuscitation. There were four treatment groups: ACA - halothane, ACA - sevoflurane and with halothane or sevoflurane sham operated animals. Vital and blood parameters were monitored during the 45min post-resuscitation intensive care phase. After a survival time of 7 days histological evaluation of the hippocampus was performed. RESULTS: We observed that resuscitated rats anesthetized prior by sevoflurane (i) have had a lower heart rate and a higher MAP compared to halothane anesthetized animals; (ii) The neurological damaged were significantly reduced in the hippocampal CA1 region in sevoflurane treated rats. CONCLUSION: Using sevoflurane instead of halothane for anesthesia requires some physiological and experimental changes. However the model keeps its validity. Sevoflurane caused less pronounced neurodegeneration in the CA1 region of the hippocampus. This had to be considered in further resuscitation-studies containing sevoflurane as anesthetic. Institutional protocol number for animal studies: 42502-2-2-947 Uni MD.

Low-dose nitroglycerine improves outcome after cardiac arrest in rats.

OBJECTIVE: The aim of this study was to evaluate the outcome of intravenously applied nitroglycerine (NTG, 1µgkg(-1)min(-1) for 1h) after resuscitation from an asphyxia cardiac arrest (ACA) insult. We hypothesized that NTG infused for 1h after the return of spontaneous circulation (ROSC) would improve functional and neuro-morphological outcomes. METHODS: Adult rats were subjected to 8min of ACA followed by resuscitation. There were three treatment groups: ACA, ACA+NTG and sham operated. Vital and blood parameters were monitored during the 1h post-resuscitation intensive care phase. After survival times of 3, 6, 12, 24, 72h and 7 days, the neurological deficit score (NDS) was measured. Histological evaluation of the hippocampus, cortex, the thalamic reticular nucleus and the caudate-putamen was performed 7 days post insult. RESULTS: We found that NTG (i) induced significantly higher initial MAP peaks; (ii) resulted in a less-pronounced elevation of heart rates after ROSC with significantly faster normalization to baseline levels; and (iii) influenced glucose metabolism, temporarily elevating blood glucose to non-physiological levels. Even so, NTG (iv) improved the neurological outcome and (v) reduced neurodegeneration, mainly in the hippocampal CA1 region. A significant NTG-associated decrease in blood pressure did not occur. CONCLUSION: The effect of low-dosed NTG applied post-resuscitation appears to be neuroprotective, demonstrated by reduced hippocampal damage and a better NDS, even with temporarily elevated blood glucose to non-physiological levels. Thus, additional studies are needed to evaluate NTG-triggered mechanisms and optimized dosages before clinical translation should be considered. Animal study institutional protocol number: 42502-2-2-947-Uni-MD.