Prehospital treatment of severely burned patients: a retrospective analysis of patients admitted to the Berlin burn centre.

BACKGROUND: Prehospital management of severely burned patients is extremely challenging. It should include adequate analgesia, decision-making on the necessity of prehospital endotracheal intubation and the administration of crystalloid fluids. Guidelines recommend immediate transport to specialised burn centres when certain criteria are met. To date, there is still insufficient knowledge on the characteristics of prehospital emergency treatment. We sought to investigate the current practice and its potential effects on patient outcome. METHODS: We conducted a single centre, retrospective cohort analysis of severely burned patients (total burned surface area > 20%), admitted to the Berlin burn centre between 2014 and 2019. The relevant data was extracted from Emergency Medical Service reports and digital patient charts for exploratory data analysis. Primary outcome was 28-day-mortality. RESULTS: Ninety patients (male/female 60/30, with a median age of 52 years [interquartile range, IQR 37-63], median total burned surface area 36% [IQR 25-51] and median body mass index 26.56 kg/m2 [IQR 22.86-30.86] were included. The median time from trauma to ED arrival was 1 h 45 min; within this time, on average 1961 ml of crystalloid fluid (0.48 ml/kg/%TBSA, IQR 0.32-0.86) was administered. Most patients received opioid-based analgesia. Times from trauma to ED arrival were longer for patients who were intubated. Neither excessive fluid treatment (> 1000 ml/h) nor transport times > 2 h was associated with higher mortality. A total of 31 patients (34,4%) died within the hospital stay. Multivariate regression analysis revealed that non-survival was linked to age > 65 years (odds ratio (OR) 3.5, 95% CI: 1.27-9.66), inhalation injury (OR 3.57, 95% CI: 1.36-9.36), burned surface area > 60% (OR 5.14, 95% CI 1.57-16.84) and prehospital intubation (5.38, 95% CI: 1.92-15.92). CONCLUSION: We showed that severely burned patients frequently received excessive fluid administration prehospitally and that this was not associated with more hemodynamic stability or outcome. In our cohort, patients were frequently intubated prehospitally, which was associated with increased mortality rates. Further research and emergency medical staff training should focus on adequate fluid application and cautious decision-making on the risks and benefits of prehospital intubation. TRIAL REGISTRATION: German Clinical Trial Registry (ID: DRKS00033516).

Stroke Volume and Stroke Volume Variation, but not Cardiac Index Is Associated With Survival of Majorly Burned Patients in Early Burn Shock.

Adequate fluid therapy is crucial to maintain organ function after burn trauma. Major burns lead to a systemic response with fluid loss and cardiac dysfunction. To guide fluid therapy, measurement of cardiac pre- and afterload is helpful. Whereas cardiac function is usually measured after admission to intensive care unit (ICU), in this study, hemodynamic monitoring was performed directly after arrival at hospital. We conducted a prospective cohort study with inclusion of 19 patients (male/female 13/6, 55 ± 18 years, mean total body surface area 36 ± 19%). Arterial waveform analysis (PulsioFlexProAqt®, Getinge) was implemented immediately after admission to hospital to measure cardiac pre- and afterload and to guide resuscitation therapy. Cardiac parameters 3.75 (2.67-6.0) h after trauma were normal regarding cardiac index (3.45 ± 0.82) L/min/m², systemic vascular resistance index (1749 ± 533) dyn sec/cm5 m2, and stroke volume (SV; 80 ± 20) mL. Stroke volume variation (SVV) was increased (21 ± 7) % and associated with mortality (mean SVV survivors vs nonsurvivors 18.92 (±6.37) % vs 27.6 (±5.68) %, P = .017). Stroke volume was associated with mortality at the time of ICU-admission (mean SV survivors vs nonsurvivors 90 (±20) mL vs 50 (±0) mL, P = .004). Changes after volume challenge were significant for SVV (24 ± 9 vs19 ± 8%, P = .01) and SV (68 ± 24 vs 76 ± 26 mL, P = .03). We described association of SVV and SV with survival of severely burned patients in an observational study. This indicates high valence of those parameters in the early postburn period. The use of an autocalibrated device enables a very early monitoring of parameters relevant to burn shock survival.

Early Autocalibrated Arterial Waveform Analysis for the Management of Burn Shock-A Cohort Study.

Adequate fluid therapy is crucial for resuscitation after major burns. To adapt this to individual patient demands, standard is adjustment of volume to laboratory parameters and values of enhanced hemodynamic monitoring. To implement calibrated parameters, patients must have reached the intensive care unit (ICU). The aim of this study was, to evaluate the use of an auto-calibrated enhanced hemodynamic monitoring device to improve fluid management before admission to ICU. We used PulsioflexProAqt® (Getinge) during initial treatment and burn shock resuscitation. Analysis was performed regarding time of measurement, volume management, organ dysfunction, and mortality. We conducted a monocentre, prospective cohort study of 20 severely burned patients, >20% total body surface area (TBSA), receiving monitoring immediately after admission. We compared to 57 patients, matched in terms of TBSA, age, sex, and existence of inhalation injury out of a retrospective control group, who received standard care. Hemodynamic measurement with autocalibrated monitoring started significantly earlier: 3.75(2.67-6.0) hours (h) after trauma in the study group versus 13.6(8.1-17.5) h in the control group (P < .001). Study group received less fluid after 6 h: 1.7(1.2-2.2) versus 2.3(1.6-2.8) ml/TBSA%/kg, P = .043 and 12 h: 3.0(2.5-4.0) versus 4.2(3.1-5.0) ml/TBSA%/kg, P = .047. Dosage of norepinephrine was higher after 18 h in the study group: 0.20(0.12-0.3) versus 0.08(0.02-0.18) µg/kg/min, P = .014. The study group showed no adult respiratory distress syndrome versus 21% in the control group, P = .031. There was no difference in other organ failures, organ replacement therapy, and mortality. The use of auto-calibrated enhanced hemodynamic monitoring is a fast and feasible way to guide early fluid therapy after burn trauma. It reduces the time to reach information about patient's volume capacity. Management of fluid application changed to a more restrictive fluid use in the early period of burn shock and led to a reduction of pulmonary complications.

Hepatobiliary long-term consequences of COVID-19: dramatically increased rate of secondary sclerosing cholangitis in critically ill COVID-19 patients.

BACKGROUND: Increasing evidence suggests that secondary sclerosing cholangitis (SSC), which can lead to cirrhosis or liver failure, may be a hepatobiliary long-term complication of COVID-19. The aim of this study was to estimate the frequency and outcome of this COVID-19 sequela and to identify possible risk factors. METHODS: This observational study, conducted at University Hospital Charité Berlin and Unfallkrankenhaus Berlin, Germany, involved hospitalized patients with COVID-19 pneumonia, including 1082 ventilated COVID-19 patients. We compared COVID-19 patients who developed SSC with a COVID-19 control group by univariate and multivariate analyses. RESULTS: SSC occurrence after COVID-19 was observed exclusively in critically ill patients with invasive ventilation, albeit with extreme clustering among them. One in every 43 invasively ventilated COVID-19 patients developed this complication. Risk factors preceding the development of secondary sclerosing cholangitis in critically ill COVID-19 patients (SSC-CIP) were signs of systemic reduced blood oxygen supply (e.g., low PaO2/FiO2, ischemic organ infarctions), multi-organ failure (high SOFA score) at admission, high fibrinogen levels and intravenous ketamine use. Multivariate analysis confirmed fibrinogen and increased plasma lactate dehydrogenase as independent risk factors associated with cholangiopathy onset. The 1-year transplant-free survival rate of COVID-19-associated SSC-CIP was 40%. CONCLUSIONS: COVID-19 causes SSC-CIP in a substantial proportion of critically ill patients. SSC-CIP most likely develops due to severe tissue hypoxia and fibrinogen-associated circulatory disturbances. A significant increase of patients with SSC-CIP is to be expected in the post-COVID era.

A Path-Deformation Framework for Determining Weighted Genome Rearrangement Distance.

Measuring the distance between two bacterial genomes under the inversion process is usually done by assuming all inversions to occur with equal probability. Recently, an approach to calculating inversion distance using group theory was introduced, and is effective for the model in which only very short inversions occur. In this paper, we show how to use the group-theoretic framework to establish minimal distance for any weighting on the set of inversions, generalizing previous approaches. To do this we use the theory of rewriting systems for groups, and exploit the Knuth-Bendix algorithm, the first time this theory has been introduced into genome rearrangement problems. The central idea of the approach is to use existing group theoretic methods to find an initial path between two genomes in genome space (for instance using only short inversions), and then to deform this path to optimality using a confluent system of rewriting rules generated by the Knuth-Bendix algorithm.

Using chloroprocaine for spinal anaesthesia in outpatient knee-arthroscopy results in earlier discharge and improved operating room efficiency compared to mepivacaine and prilocaine.

PURPOSE: Knee arthroscopies are regularly carried out in an outpatient setting. The purpose of this retrospective analysis was to investigate the impact of different local anaesthetics for spinal anaesthesia on operating room efficiency (perioperative process times) and postoperative recovery. This study aims to determine the optimal LA for SPA in patients undergoing knee arthroscopy at a day-surgery centre. METHODS: Anaesthesia records of all patients undergoing knee arthroscopy under spinal anaesthesia from 2010 until 2017 were analysed. Patients were categorised as having received spinal anaesthesia with prilocaine, mepivacaine or chloroprocaine. RESULTS: Three-hundred and nine patients were included. Postoperative recovery was significantly faster for chloroprocaine 1% compared with both other local anaesthetics regarding all stages of recovery until discharge. Perioperative processes and surgery time were significantly shorter when chloroprocaine was used. Early postoperative pain occurred more frequently and earlier after spinal anaesthesia with chloroprocaine. Nevertheless, pain intensity did not differ between groups. CONCLUSION: Spinal anaesthesia provides reliable blocks for outpatient knee arthroscopy. Considerations on the choice of local anaesthetic for spinal anaesthesia must include not only the recovery profile, but also the impact on operating room efficiency. Due to a superior recovery profile, low incidences of adverse side effects and raised operating room efficiency, chloroprocaine is the recommendable local anaesthetic for spinal anaesthesia in patients undergoing knee arthroscopy in an ambulatory setting. Since the frequency of SPA in patients undergoing outpatient knee arthroscopy is rising yearly, the results of this study are of high clinical relevance. The use of chloroprocaine leads to improved recovery, optimized perioperative processes and consecutively to a raised OR efficiency. LEVEL OF EVIDENCE: III.

Influence of anxiolytic premedication on vasovagal reactions and home readiness following outpatient intrathecal anaesthesia-A retrospective analysis.

BACKGROUND: Vasovagal reactions during application of intrathecal anaesthesia (IA) are associated with high anxiety levels. A high percentage of patients undergoing outpatient surgery suffer from anxiety. Anxiolytic premedication in day-surgery is suspected to delay recovery and discharge and is, therefore, not routinely used. The aim of this retrospective analysis was to detect the influence of anxiolytic premedication on the incidence of vasovagal reactions and time until discharge home. METHODS: Anaesthesia records of all patients undergoing outpatient surgery under low-dose IA from January 2008 to June 2017 were analysed. Incidences of vasovagal reactions with a decrease in blood pressure and/or heart rate and need for cardiovascular activating medications were documented. Patients were categorised as having received an anxiolytic premedication or not. The time from intrathecal injection of the local anaesthetic until readiness for discharge was recorded. RESULTS: The records of 2747 patients were analysed. One thousand two hundred and ninety-one of them received an anxiolytic premedication of 1-2 mg midazolam intravenously. Three hundred and fourteen patients had vasovagal incidents during application of IA (no premedication n = 217 [15.0%], premedication n = 97 [7.5%], P < 0.0001). Premedication did not prolong time to achieve readiness for discharge (mepivacaine: P = 0.5886, chloroprocaine: P = 0.1555). However, in the prilocaine group, premedication led to a significantly earlier achievement of readiness for discharge (P = 0.0002). CONCLUSION: Anxiolytic premedication significantly reduces the incidence of vasovagal reactions during the application of IA and does not affect time until readiness for discharge.

Retrospective analysis of mepivacaine, prilocaine and chloroprocaine for low-dose spinal anaesthesia in outpatient perianal procedures.

PURPOSE: Perianal procedures are carried out in an outpatient setting regularly. The purpose of this retrospective analysis was to investigate the impact of different local anaesthetics (LA) for spinal anaesthesia (SPA) on operating room (OR) efficiency (perioperative process times, turnaround times) and postoperative recovery. This study aims on the determination of the optimal LA for low-dose SPA in the specific setting of a high-volume day-surgery centre. METHODS: Anaesthesia records of all patients undergoing perianal outpatient surgery under saddle-block SPA at the Mannheim University Medical Centre from 2008 until 2017 were analysed. Patients were categorized as having received prilocaine, mepivacaine or chloroprocaine. RESULTS: Two thousand seven hundred forty-six patients were included. Postoperative recovery was faster for chloroprocaine 1% compared with both other LAs. Preoperative processes but not process times in the OR were shorter for chloroprocaine. In contrary, turnaround times were significantly prolonged when chloroprocaine had been used, leading to reduction of OR efficiency. CONCLUSION: Low-dose SPA provides reliable blocks for perianal surgery. Considerations on the choice of LA for SPA must include not only the recovery profile, but also the impact on OR efficiency. Due to shorter turnaround times and a manageable prolonged duration of stay, prilocaine is the preferable LA for low-dose SPA in perianal outpatient surgery at a high-volume day-surgery centre.

Spinal anaesthesia with chloroprocaine 1% versus total intravenous anaesthesia for outpatient knee arthroscopy: A randomised controlled trial.

BACKGROUND: Both general and spinal anaesthesia with short-acting local anaesthetics are suitable and reliable for knee arthroscopy as an ambulatory procedure. Chloroprocaine (CP) 1% seems to be the ideal spinal local anaesthetic for this indication. OBJECTIVE: The aim of this study was to compare spinal anaesthesia using CP 1% with general for outpatient knee arthroscopy with regard to procedure times, occurrence of pain, patient satisfaction and recovery, and also costs. DESIGN: A randomised controlled single-centre trial. SETTING: University Medical Centre Mannheim, Department of Anaesthesiology and Surgical Intensive Care Medicine, Mannheim, Germany. April 2014 to August 2015. PATIENTS: A total of 50 patients (women/men, 18 to 80 years old, ASA I to III) undergoing outpatient knee arthroscopy were included. A contra-indication to an allocated anaesthetic technique or an allergy to medication required in the protocol led to exclusion. INTERVENTIONS: Either general anaesthesia with sufentanil, propofol and a laryngeal mask for airway-management or spinal with 40-mg CP 1% were used. We noted procedure times, patient satisfaction/recovery and conducted a 7-day follow-up. MAIN OUTOMES: Primary outcome was duration of stay in the day-surgery centre. Secondary outcomes were first occurrence of pain, patient satisfaction, quality of recovery and adverse effects. In addition, we analysed treatment costs. RESULTS: Spinal had faster recovery than general anaesthesia with patients reaching discharge criteria significantly earlier [117 min (66 to 167) versus 142 min (82 to 228), P = 0.0047]. Pain occurred significantly earlier in the general anaesthesia group (P = 0.0072). Costs were less with spinal anaesthesia (cost ratio spinal: general 0.57). Patients felt significantly more uncomfortable after general anaesthesia (P = 0.0096). CONCLUSION: Spinal anaesthesia with 40-mg CP 1% leads to a significantly earlier discharge and is cheaper compared with general. TRIAL REGISTRATION: German Clinical Trials Register, www.drks.de, identifier: DRKS00005989.

[New short-acting local anaesthetics for spinal anaesthesia - Well-tried substances for ambulatory surgery]. / Neue kurzwirksame Lokalanästhetika in der Spinalanästhesie - Altbewährte Substanzen für ambulante Eingriffe.

More and more operative procedures are performed in an ambulatory setting. Many patients are denied spinal anaesthesia, although it provides several advantages. Innovative pharmaceutical formulations of well-tried local anaesthetics have created "new" substances that are ideal for ambulatory surgery due to their fast onset, short duration of action, and very low incidence of complications such as transient neurological symptoms (TNS). Both hyperbaric prilocaine 2% and preservative-free chloroprocaine 1% were recently approved for spinal application in Germany. Additional perioperative measures, such as the use of atraumatic, thin spinal needles (25 or 27G), restrictive volume management, and early patient mobilisation, lead to a further reduction of complications. The new S1 guideline of the German Society of Anaesthesiology and Intensive Care Medicine encourages us anaesthetists to use spinal anaesthesia more frequently in an ambulatory setting.

Group-theoretic models of the inversion process in bacterial genomes.

The variation in genome arrangements among bacterial taxa is largely due to the process of inversion. Recent studies indicate that not all inversions are equally probable, suggesting, for instance, that shorter inversions are more frequent than longer, and those that move the terminus of replication are less probable than those that do not. Current methods for establishing the inversion distance between two bacterial genomes are unable to incorporate such information. In this paper we suggest a group-theoretic framework that in principle can take these constraints into account. In particular, we show that by lifting the problem from circular permutations to the affine symmetric group, the inversion distance can be found in polynomial time for a model in which inversions are restricted to acting on two regions. This requires the proof of new results in group theory, and suggests a vein of new combinatorial problems concerning permutation groups on which group theorists will be needed to collaborate with biologists. We apply the new method to inferring distances and phylogenies for published Yersinia pestis data.

Randomised clinical trial of pilonidal sinus operations performed in the prone position under spinal anaesthesia with hyperbaric bupivacaine 0.5 % versus total intravenous anaesthesia.

PURPOSE: The aim of this randomised clinical trial was to determine whether spinal anaesthesia (SPA) is superior to total intravenous anaesthesia (TIVA) in patients undergoing pilonidal sinus (PS) operations in the prone position. METHODS: After approval of the local ethics committee, suitable patients aged 19-49 years were randomised to SPA (7.5 mg hyperbaric bupivacaine) or TIVA (Propofol and Fentanyl). Cumulative consumption of analgesics, postoperative recovery, complications and patient satisfaction were evaluated. RESULTS: A total of 50 patients were randomised within a 24-month period. Median monitoring time in the recovery room was 0 (0-11) min for SPA versus 40 (5-145) min for TIVA (p < 0.0001). Patients in the SPA group were able to drink (40.5 (0-327) min versus TIVA 171 (72-280) min, p < 0.0001) and eat (55 (0-333) min versus TIVA 220 (85-358), p < 0.0001) earlier. More patients with a TIVA needed analgesics in the recovery room (SPA n = 0 versus TIVA n = 6, p = 0.0023) and suffered more frequently from a sore throat (SPA n = 0 versus TIVA n = 11, p = 0.0001). Two patients with a TIVA suffered from nausea and vomiting. Patients of both groups were equally satisfied with the anaesthesia technique offered. CONCLUSIONS: SPA with 7.5 mg hyperbaric bupivacaine is superior to TIVA in patients undergoing PS operations in the prone position in terms of analgesia consumption in the recovery room, recovery times and postoperative complications.