[Implementation of fast-track measures in colorectal resections : A survey among members of the DGAI]

PURPOSE

The fast-track (FT) concept is a multimodal, interdisciplinary approach to perioperative patient care intended to reduce postoperative complications. Despite good evidence implementation seems to need improvement, whereby almost all studies focused on the implementation of surgical modules regardless of the interdisciplinary aspect. Adherence to the anesthesiological measures (prehabilitation, premedication, volume and temperature management, pain therapy), on the other hand, has been insufficiently studied. To assess the status quo a survey on the implementation of anesthesiological FT measures was conducted among members of the German Society of Anesthesiology and Intensive Care Medicine (DGAI) to analyze where potential for improvement exists.

METHODS

Using the SurveyMonkey® online survey tool, 28 questions regarding perioperative anesthesiological care of colorectal surgery patients were sent to DGAI members in order to analyze adherence to FT measures.

RESULTS

While some of the FT measures (temperature management, PONV prophylaxis) are already routinely used, there is a divergence between current recommendations and clinical implementation for other components. In addition to premedication, interdisciplinary measures (prehabilitation) and measures that affect multiple interfaces (operating theatre, recovery room, ward), such as volume management or perioperative pain management, are particularly affected.

CONCLUSION

The anesthesiological recommendations of the FT concept are only partially implemented in Germany. This particularly affects the interdisciplinary components as well as measures at the operating theatre, recovery room and ward interfaces. The establishment of an interdisciplinary FT team and interdisciplinary development of SOPs can optimize adherence, which in turn improves the short-term and long-term outcome of patients.

Parameters predicting COVID-19-induced myocardial injury and mortality

Clinical manifestations of COVID-19 affect many organs, including the heart. Cardiovascular disease is a dominant comorbidity and prognostic factors predicting risk for critical courses are highly needed. Moreover, immunomechanisms underlying COVID-induced myocardial damage are poorly understood.

OBJECTIVE

To elucidate prognostic markers to identify patients at risk.

RESULTS

Only patients with pericardial effusion (PE) developed a severe disease course, and those who died could be identified by a high CD8/Treg/monocyte ratio. Ten out of 19 COVID-19 patients presented with PE, 7 (78%) of these had elevated APACHE-II mortality risk-score, requiring mechanical ventilation. At admission, PE patients showed signs of systemic and cardiac inflammation in NMR and impaired cardiac function as detected by transthoracic echocardiography (TTE), whereas parameters of myocardial injury e.g. high sensitive troponin-t (hs-TnT) were not yet increased. During the course of disease, hs-TnT rose in 8 of the PE-patients above 16 ng/l, 7 had to undergo ventilatory therapy and 4 of them died. FACS at admission showed in PE patients elevated frequencies of CD3⁺CD8⁺ T cells among all CD3+ T-cells, and lower frequencies of Tregs and CD14⁺HLA^-DR⁺-monocytes. A high CD8/Treg/monocyte ratio predicted a severe disease course in PE patients, and was associated with high serum levels of antiviral cytokines. By contrast, patients without PE and PE patients with a low CD8/Treg/monocyte ratio neither had to be intubated, nor died.

CONCLUSIONS

PE predicts cardiac injury in COVID-19 patients. Therefore, TTE should be performed at admission. Immunological parameters for dysfunctional antiviral immunity, such as the CD8/Treg/monocyte ratio used here, supports risk assessment by predicting poor prognosis.

Parameters predicting COVID-19-induced myocardial injury and mortality

Clinical manifestations of COVID-19 affect many organs, including the heart. Cardiovascular disease is a dominant comorbidity and prognostic factors predicting risk for critical courses are highly needed. Moreover, immunomechanisms underlying COVID-induced myocardial damage are poorly understood.

OBJECTIVE

To elucidate prognostic markers to identify patients at risk.

RESULTS

Only patients with pericardial effusion (PE) developed a severe disease course, and those who died could be identified by a high CD8/Treg/monocyte ratio. Ten out of 19 COVID-19 patients presented with PE, 7 (78%) of these had elevated APACHE-II mortality risk-score, requiring mechanical ventilation. At admission, PE patients showed signs of systemic and cardiac inflammation in NMR and impaired cardiac function as detected by transthoracic echocardiography (TTE), whereas parameters of myocardial injury e.g. high sensitive troponin-t (hs-TnT) were not yet increased. During the course of disease, hs-TnT rose in 8 of the PE-patients above 16 ng/l, 7 had to undergo ventilatory therapy and 4 of them died. FACS at admission showed in PE patients elevated frequencies of CD3⁺CD8⁺ T cells among all CD3+ T-cells, and lower frequencies of Tregs and CD14⁺HLA^-DR⁺-monocytes. A high CD8/Treg/monocyte ratio predicted a severe disease course in PE patients, and was associated with high serum levels of antiviral cytokines. By contrast, patients without PE and PE patients with a low CD8/Treg/monocyte ratio neither had to be intubated, nor died.

CONCLUSIONS

PE predicts cardiac injury in COVID-19 patients. Therefore, TTE should be performed at admission. Immunological parameters for dysfunctional antiviral immunity, such as the CD8/Treg/monocyte ratio used here, supports risk assessment by predicting poor prognosis.

Risks to healthcare workers following tracheal intubation of patients with COVID-19: a prospective international multicentre cohort study

Healthcare workers involved in aerosol‐generating procedures, such as tracheal intubation, may be at elevated risk of acquiring COVID‐19. However, the magnitude of this risk is unknown. We conducted a prospective international multicentre cohort study recruiting healthcare workers participating in tracheal intubation of patients with suspected or confirmed COVID‐19. Information on tracheal intubation episodes, personal protective equipment use and subsequent provider health status was collected via self‐reporting. The primary endpoint was the incidence of laboratory‐confirmed COVID‐19 diagnosis or new symptoms requiring self‐isolation or hospitalisation after a tracheal intubation episode. Cox regression analysis examined associations between the primary endpoint and healthcare worker characteristics, procedure‐related factors and personal protective equipment use. Between 23 March and 2 June 2020, 1718 healthcare workers from 503 hospitals in 17 countries reported 5148 tracheal intubation episodes. The overall incidence of the primary endpoint was 10.7% over a median (IQR [range]) follow‐up of 32 (18–48 [0–116]) days. The cumulative incidence within 7, 14 and 21 days of the first tracheal intubation episode was 3.6%, 6.1% and 8.5%, respectively. The risk of the primary endpoint varied by country and was higher in women, but was not associated with other factors. Around 1 in 10 healthcare workers involved in tracheal intubation of patients with suspected or confirmed COVID‐19 subsequently reported a COVID‐19 outcome. This has human resource implications for institutional capacity to deliver essential healthcare services, and wider societal implications for COVID‐19 transmission.

Implementation of anesthesia quality indicators in Germany : A prospective, national, multicenter quality improvement study

BACKGROUND

In 2016 the German Society of Anesthesiology and Intensive Care Medicine (DGAI) and the Association of German Anesthetists (BDA) published 10 quality indicators (QI) to compare and improve the quality of anesthesia care in Germany. So far, there is no evidence for the feasibility of implementation of these QI in hospitals.

OBJECTIVE

This study tested the hypothesis that the implementation of the 10 QI is feasible in German hospitals.

MATERIAL AND METHODS

This prospective three-phase national multicenter quality improvement study was conducted in 15 German hospitals and 1 outpatient anesthesia center from March 2017 to February 2018. The trial consisted of an initial evaluation of pre-existing structures and processes by the heads of the participating anesthesia departments, followed by a 6-month implementation phase of the QI as well as a final re-evaluation phase. The implementation procedure was supported by web-based implementation aids ( www.qi-an.org ) and internal quality management programs. The primary endpoint was the difference in the number of implemented QI per center before and after implementation. Secondary endpoints were the number of newly implemented QI per center, the overall number of successful implementations of each QI, the identification of problems during the implementation as well as the kind of impediments preventing the QI implementation.

RESULTS

The average number of implemented QI increased from 5.8 to 6.8 (mean of the differences 1.1 ± 1.3; P < 0.01). Most frequently the QI perioperative morbidity and mortality report (5 centers) and the QI temperature management (4 centers) could be implemented. After the implementation phase, the QI incidence management and patient blood management were implemented in all 16 centers. Implementation of other quality indicators failed mainly due to a lack of time and lack of structural resources.

CONCLUSION

In this study the implementation of QI was proven to be mostly feasible in the participating German hospitals. Although several QI could be implemented with minor effort, more time, financial and structural resources would be required for some QI, such as the QI postoperative visit.

[Implementation of anesthesia quality indicators in Germany : A prospective, national, multicenter quality improvement study]

BACKGROUND

In 2016 the German Society of Anesthesiology and Intensive Care Medicine (DGAI) and the Association of German Anesthetists (BDA) published 10 quality indicators (QI) to compare and improve the quality of anesthesia care in Germany. So far, there is no evidence for the feasibility of implementation of these QI in hospitals.

OBJECTIVE

This study tested the hypothesis that the implementation of the 10 QI is feasible in German hospitals.

MATERIAL AND METHODS

This prospective three-phase national multicenter quality improvement study was conducted in 15 German hospitals and 1 outpatient anesthesia center from March 2017 to February 2018. The trial consisted of an initial evaluation of pre-existing structures and processes by the heads of the participating anesthesia departments, followed by a 6-month implementation phase of the QI as well as a final re-evaluation phase. The implementation procedure was supported by web-based implementation aids ( www.qi-an.org ) and internal quality management programs. The primary endpoint was the difference in the number of implemented QI per center before and after implementation. Secondary endpoints were the number of newly implemented QI per center, the overall number of successful implementations of each QI, the identification of problems during the implementation as well as the kind of impediments preventing the QI implementation.

RESULTS

The average number of implemented QI increased from 5.8 to 6.8 (mean of the differences 1.1 ± 1.3; P < 0.01). Most frequently the QI perioperative morbidity and mortality report (5 centers) and the QI temperature management (4 centers) could be implemented. After the implementation phase, the QI incidence management and patient blood management were implemented in all 16 centers. Implementation of other quality indicators failed mainly due to a lack of time and lack of structural resources.

CONCLUSION

In this study the implementation of QI was proven to be mostly feasible in the participating German hospitals. Although several QI could be implemented with minor effort, more time, financial and structural resources would be required for some QI, such as the QI postoperative visit.

[Delirium in intensive care patients : A multiprofessional challenge]

Delirium is the most common form of cerebral dysfunction in intensive care patients and is a medical emergency that must be avoided or promptly diagnosed and treated. According to current knowledge the development of delirium seems to be caused by an interplay between increased vulnerability (predisposition) and simultaneous exposure to delirogenic factors. Since delirium is often overlooked in the clinical routine, a continuous screening for delirium should be performed. Due to the close connection between delirium, agitation and pain, sedation and analgesia must be evaluated at least every 8 h analogous to delirium screening. According to current knowledge, a multifactorial and multiprofessional approach is favored in the prevention and treatment of delirium. Non-pharmaceutical interventions through early mobilization, reorientation, sleep improvement, adequate pain therapy and avoidance of polypharmacy are of great importance. Depending on the clinical picture, different substances are used in symptom-oriented drug treatment of delirium. In order to achieve these diagnostic and therapeutic goals, an interdisciplinary treatment team consisting of intensive care, intensive care physicians, ward pharmacists, physiotherapists, nutrition specialists and psychiatrists is necessary in order to meet the requirements of the patient and their relatives.

[Geriatric Trauma Center DGU®: Evaluation of clinical and economic parameters : A pilot study in a german university hospital]

BACKGROUND

Previous studies on orthogeriatric models of care suggest that there is substantial variability in how geriatric care is integrated in the patient management and the necessary intensity of geriatric involvement is questionable.

OBJECTIVE

The aim of the current prospective cohort study was the clinical and economic evaluation of fragility fracture treatment pathways before and after the implementation of a geriatric trauma center in conformity with the guidelines of the German Trauma Society (DGU).

METHODS

A comparison of three different treatment models (6 months each) was performed: A: Standard treatment in Orthopaedic Trauma; B: Special care pathways with improvement of the quality management system and implementation of standard operating procedures; C: Interdisciplinary treatment with care pathways and collaboration with geriatricians (ward round model).

RESULTS

In the 151 examined patients (m/w 47/104; 83.5 (70-100) years; A: n = 64, B: n = 44, C: n = 43) pathways with orthogeriatric comanagement (C) improved frequency of postoperative mobilization (p = 0.021), frequency of osteoporosis prophylaxis (p = 0.001) and the discharge procedure (p = 0.024). In comparison to standard treatment (A), orthogeriatric comanagement (C) was associated with lower rates of mortality (9% vs. 2%; p = 0.147) and cardio-respiratory complications (39% vs. 28%; p = 0.235) by trend. In this context, there were low rates of myocardial infarction (6% vs. 0%), dehydration (6% vs. 0%), cardiac dysrhythmia (8% vs. 0%), pulmonary decompensation (28% vs. 16%), electrolyt dysbalance (34% vs. 19%) and pulmonary edema (11% vs. 2%). Duration of stay in an intensive care unit was 29 h (A) and 18 h (C) respectively (p = 0.205), with consecutive reduction in costs. A sole establishment of a special care pathway for older hip fracture patients (B) showed a lower rate of myocardial infarction (A: 11%, B: 0%, C: 0%; p = 0.035).

CONCLUSION

There was a clear tendency to a better overall result in patients receiving multidisciplinary orthogeriatric treatment using a ward visit model of orthogeriatric comanagement, with lower rates of cardiorespiratory complications and mortality. While special care pathways could reduce the rate of myocardial infarction in hip fracture patients, costs and revenues showed no difference between all care models evaluated. However, patients with hip fracture or periprosthetic fracture represent cohorts at clinical and economic risk as well.

Risks and prevention of surgical fires : A systematic review

Surgically induced fire is a life-threatening hazard; this topic has received little attention, although only 3 factors, the so-called fire triad, are needed for surgical fires to occur: an oxidizer, fuel and an ignition source. This systematic review aims to determine the impact of each component and to delegate every staff member an area of responsibility, thus ensuring patient health through prevention or protection. The trial was registered in Prospero CRD42018082656. A database search of eligible, preferably evidence-based studies was conducted. The Robins-I tool for assessing the risk of bias revealed a moderate risk of bias. Due to insufficient data, the main findings of these studies could not be summarized through a quantitative synthesis; therefore, a qualitative synthesis is outlined. The results are summarized according to the roles of the fire triad and discussed. (1) Role of the oxidizer: oxygen is the key component of the triad. Safe oxygen delivery is important. An oxygen-enriched environment (ORE) is caused by draping and is preferably prevented by suctioning. Fuel characteristics are affected by varying oxygen concentrations. (2) Role of the ignition source: electrocauterization is the most common ignition source, followed by lasers. Less common ignition sources include fiberoptic cables and preparative solutions, petrol or acetone. (3) Role of the fuel: surgical drapes are one of the most common fuels for surgical fires followed by the patient's hair and skin. Skin preparation solutions are among the less common fuels. Many fire-resistant materials have been tested that do not remain fire resistant in ORE. It was concluded that the main problem is defining the real extent of this hazard. Exact numbers and exact condition protocols are needed; therefore, standardized registration of every fire and future studies with much evidence are needed. Immediate prevention consists of close attention to patient safety to prevent surgical fires from happening.

Argon does not affect cerebral circulation or metabolism in male humans

OBJECTIVE

Accumulating data have recently underlined argon´s neuroprotective potential. However, to the best of our knowledge, no data are available on the cerebrovascular effects of argon (Ar) in humans. We hypothesized that argon inhalation does not affect mean blood flow velocity of the middle cerebral artery (Vmca), cerebral flow index (FI), zero flow pressure (ZFP), effective cerebral perfusion pressure (CPPe), resistance area product (RAP) and the arterio-jugular venous content differences of oxygen (AJVDO2), glucose (AJVDG), and lactate (AJVDL) in anesthetized patients.

MATERIALS AND METHODS

In a secondary analysis of an earlier controlled cross-over trial we compared parameters of the cerebral circulation under 15 minutes exposure to 70%Ar/30%O2 versus 70%N2/30%O2 in 29 male patients under fentanyl-midazolam anaesthesia before coronary surgery. Vmca was measured by transcranial Doppler sonography. ZFP and RAP were estimated by linear regression analysis of pressure-flow velocity relationships of the middle cerebral artery. CPPe was calculated as the difference between mean arterial pressure and ZFP. AJVDO2, AJVDG and AJVDL were calculated as the differences in contents between arterial and jugular-venous blood of oxygen, glucose, and lactate. Statistical analysis was done by t-tests and ANOVA.

RESULTS

Mechanical ventilation with 70% Ar did not cause any significant changes in mean arterial pressure, Vmca, FI, ZFP, CPPe, RAP, AJVDO2, AJVDG, and AJVDL.

DISCUSSION

Short-term inhalation of 70% Ar does not affect global cerebral circulation or metabolism in male humans under general anaesthesia.

[Neuroprotection by noble gases: New developments and insights]

Noble gases are chemically inert elements, some of which exert biological activity. Experimental neuroprotection in particular has been widely shown for xenon, argon and helium. The underlying mechanisms of action are not yet fully understood. Besides an interference with neuronal ion-gated channels and cellular signaling pathways as well as anti-apoptotic effects, the modulation of neuroinflammation seems to play a crucial role. This review presents the current knowledge on neuroprotection by noble gases with a focus on interactions with the neuronal-glial network and neuroinflammation and the perspectives on clinical applications.

Delayed cerebral ischaemia prevention and treatment after aneurysmal subarachnoid haemorrhage: a systematic review

: The leading cause of morbidity and mortality after surviving the rupture of an intracranial aneurysm is delayed cerebral ischaemia (DCI). We present an update of recent literature on the current status of prevention and treatment strategies for DCI after aneurysmal subarachnoid haemorrhage. A systematic literature search of three databases (PubMed, ISI Web of Science, and Embase) was performed. Human clinical trials assessing treatment strategies, published in the last 5 yr, were included based on full-text analysis. Study data were extracted using tables depicting study type, sample size, and outcome variables. We identified 49 studies meeting our inclusion criteria. Clazosentan, magnesium, and simvastatin have been tested in large high-quality trials but failed to show a beneficial effect. Cilostazol, eicosapentaenoic acid, erythropoietin, heparin, and methylprednisolone yield promising results in smaller, non-randomized or retrospective studies and warrant further investigation. Topical application of nicardipine via implants after clipping has been shown to reduce clinical and angiographic vasospasm. Methods to improve subarachnoid blood clearance have been established, but their effect on outcome remains unclear. Haemodynamic management of DCI is evolving towards euvolaemic hypertension. Endovascular rescue therapies, such as percutaneous transluminal balloon angioplasty and intra-arterial spasmolysis, are able to resolve angiographic vasospasm, but their effect on outcome needs to be proved. Many novel therapies for preventing and treating DCI after aneurysmal subarachnoid haemorrhage have been assessed, with variable results. Limitations of the study designs often preclude definite statements. Current evidence does not support prophylactic use of clazosentan, magnesium, or simvastatin. Many strategies remain to be tested in larger randomized controlled trials.

CLINICAL TRIAL REGISTRATION

This systematic review was registered in the international prospective register of systematic reviews.

PROSPERO

CRD42015019817.

Investigation of the efficacy and tolerability of Dr Michaels® (also branded as Eczitinex® and Itchinex Eczitinex®) topical products in the treatment of atopic dermatitis in children

Atopic eczema is a chronic relapsing inflammatory skin disorder, characterized clinically by intensely pruritic eczematous skin lesions and a defective epidermal barrier. It affects more than 15% of children and up to 10%of adults, which makes the disease a social health problem still without a challenging treatment. The aim of this study was to evaluate the efficacy and tolerability of Dr Michaels® (Eczitinex®) topical product family in the treatment of atopic dermatitis in children. We studied a group of 30 patients (17 female, 13 male), aged 5 to 13 (mean age: 9), affected by atopic dermatitis since they were newborn. All patients had been unsuccessfully treated with conventional anti-inflammatory therapies and ceased treatment 2 weeks before commencing research. The patients were treated with Dr Michaels® (Eczitinex® and Itchinex®) product family including a moisturising bar, topical ointment and PSC 900 oral herbal formulation. The treatment was evaluated clinically and photographically at 0, 1, 2, 4, 6, 8, 10, 12, and 14 weeks. Twenty-eight patients showed a significant improvement of cutaneous rashes and pruritus on the first week of treatment, with a complete remission at 10-12 weeks. Only two patients, brother and sister respectively, showed a slow response to treatment and reported an increasing itching. Following 14 weeks of treatment with the Dr Michaels® (Eczitinex® and Itchinex®) product family, patients demonstrated complete resolution of their AD. All patients showed a marked improvement in their condition within 3 days of treatment with most of the lesions and symptoms totally resolved within 10 to 12 weeks of treatment with Dr Michaels® (Eczitinex® and Itchinex®) family of products. This clinical report highlights that the Dr Michaels® (Eczitinex® and Itchinex®) product family is a safe and effective treatment option for AD.

Successful treatment of mild to moderate acne vulgaris with Dr Michaels® (also branded as Zitinex®) topical products family: a clinical trial

Acne vulgaris is an epidemic inflammatory skin disease of multi-factorial origin, frequently seen in adolescents and often persisting or occurring through to adulthood. Acne vulgaris is a nearly universal skin disease afflicting 79-95% of the adolescent population in westernized societies and is a significant cause of psychological morbidity in affected patients. Despite the various treatment options available for acne, there is still a need for a safe and effective option. The aim of the study was to investigate the efficacy and tolerability of Dr Michaels® (Zitinex®) product family in the treatment of papulo-pustular acne. 25 patients (17 female/8 male), aged 15-22, with a mild to moderate papulo-pustular acne, localized on the face and on the trunk, were included in this study. None of the patients had used any other kind of treatment in the 3 months prior to commencing this study. All of the patients were treated with Dr Michaels® (Zitinex®) facial exfoliating cleanser, activator formula, a cream, PSC 200 and PSC 900 oral supplements. Application time of Dr Michaels® (Zitinex®) products was 12 weeks. The treatment was been evaluated clinically at 0, 4, 8 and 12 weeks. All of the patients showed an improvement in all parameters of their acne (comedones, papules, pustules, hyperpigmentation and scars). The acne lesions and erythema had mostly resolved. The hyperpigmentation and pitted scarring had significantly reduced also, with the skin appearing smoother. The treatment was well tolerated and no side effects have been described. Our study demonstrates that the Dr Michaels® (Zitinex®) facial exfoliating cleanser, activator formula, cream and oral supplements PSC 200 and PSC 900 are an effective therapeutic option for the treatment of moderately severe acne vulgaris. Moreover, it highlights the safety profile of the Dr Michaels® (Zitinex®) product family in a case of acne compared to traditional first-line treatments.

Successful treatment of recalcitrant candidal intertrigo with Dr Michaels® (Fungatinex®) product family

Candidal intertrigo is an infection of the skin caused by Candida albicans that typically occurs in opposing cutaneous or muco-cutaneous surfaces. Because Candidiasis requires a damaged and moist environment for infection, it typically occurs in areas of friction such as the skin folds of the body. Candidal intertrigo is often difficult to treat and results are often unsatisfactory. In addition, there is a lack of evidence-based literature supporting prevention and treatments for candidal intertrigo. The aim of the study was to evaluate the efficacy of Dr Michaels® (also branded as Fungatinex®) products in the treatment of fungal intertrigo, in 20 women and 2 men with a mean age of 72. Five patients (3 female and 2 male) had type 2 diabetes and 16 (14 female and 2 male) were obese. The patients were treated with Dr Michaels® (Fungatinex®) moisturising bar, topical ointment (twice daily application) and oral herbal formulation, PSC 200 two tablets twice daily with food. After 2 weeks of treatment, the lesions had mostly resolved in all patients with only slight erythema evident. After six weeks of treatment using the moisturising bar, topical ointment and oral herbal formulations from the Dr Michaels® (Fungatinex®) product family, the lesions had totally resolved in 18 patients, while 4 patients had to continue the therapeutic protocol for another 2 weeks. Our results demonstrate that the Dr Michaels® (Fungatinex®) complementary product family is efficacious in the treatment of recalcitrant candidal intertrigo. Furthermore, this study highlights that the Dr Michaels® (Fungatinex®) product family is fast-acting and well tolerated with no serious adverse events reported. These data have important implications for resistant cases of candidal intertrigo where traditional therapies have failed.

Intubation performance using different laryngoscopes while wearing chemical protective equipment: a manikin study

OBJECTIVES

This study aimed to compare visualisation of the vocal cords and performance of intubation by anaesthetists using four different laryngoscopes while wearing full chemical protective equipment.

SETTING

Medical simulation center of a university hospital, department of anaesthesiology.

PARTICIPANTS

42 anaesthetists (15 females and 27 males) completed the trial. The participants were grouped according to their professional education as anaesthesiology residents with experience of <2 years or <5 years, or as anaesthesiology specialists with experience of >5 years.

INTERVENTIONS

In a manikin scenario, participants performed endotracheal intubations with four different direct and indirect laryngoscopes (Macintosh (MAC), Airtraq (ATQ), Glidescope (GLS) and AP Advance (APA)), while wearing chemical protective gear, including a body suit, rubber gloves, a fire helmet and breathing apparatus.

PRIMARY AND SECONDARY OUTCOME MEASURES

With respect to the manikin, setting time to complete 'endotracheal intubation' was defined as primary end point. Glottis visualisation (according to the Cormack-Lehane score (CLS) and impairments caused by the protective equipment, were defined as secondary outcome measures.

RESULTS

The times to tracheal intubation were calculated using the MAC (31.4 s; 95% CI 26.6 to 36.8), ATQ (37.1 s; 95% CI 28.3 to 45.9), GLS (35.4 s; 95% CI 28.7 to 42.1) and APA (23.6 s; 95% CI 19.1 to 28.1), respectively. Intubation with the APA was significantly faster than with all the other devices examined among the total study population (p<0.05). A significant improvement in visualisation of the vocal cords was reported for the APA compared with the GLS.

CONCLUSIONS

Despite the restrictions caused by the equipment, the anaesthetists intubated the manikin successfully within adequate time. The APA outperformed the other devices in the time to intubation, and it has been evaluated as an easily manageable device for anaesthetists with varying degrees of experience (low to high), providing good visualisation in scenarios that require the use of chemical protective equipment.

[Perioperative management of patients with obstructive sleep apnea : update on the practice guidelines of the American Society of Anesthesiologists Task Force]

Obstructive sleep apnea (OSA) is a widespread disease which is associated with many cardiovascular diseases and can have health-related consequences for affected patients if untreated. It is known that perioperative airway complications occur more often in OSA patients during general anesthesia. Some years ago the Task Force of the American Society of Anesthesiologists (ASA) published practice guidelines on the perioperative approach to OSA patients. These guidelines have now been revised and updated. This article gives a summary of the recommended approach for the perioperative treatment of patients with OSA given in the 2014 guidelines.

aepEX monitor for the measurement of hypnotic depth in patients undergoing balanced xenon anaesthesia

BACKGROUND

Previously, we showed a significant difference in the measurements of hypnotic depth by the bispectral index (BIS) and auditory-evoked potentials (AEPs) using the A-line autoregressive index during xenon anaesthesia. In the present study, we evaluate the alternative AEP-based auditory-evoked potential index (aepEX) for the measurement of hypnotic depth in patients undergoing general anaesthesia with xenon.

METHODS

Forty-two patients undergoing elective abdominal surgery were enrolled in this controlled, double-blinded, randomized, clinical study. Patients were randomized to receive either xenon (n=21) or sevoflurane anaesthesia (n=21). During anaesthesia, BIS values were recorded simultaneously with the aepEX monitoring. The anaesthetist performing the anaesthesia was blinded to the hypnotic depth monitors. After surgery, the incidence of recalls and awareness was evaluated.

RESULTS

Patients' characteristics such as gender, age, and weight did not differ between the groups. The aepEX and BIS values behaved similarly during anaesthesia. The comparison of aepEX values during xenon and sevoflurane anaesthesia revealed significantly lower aepEX values in the xenon group after 25 min [xenon: 32.9 (4.8) vs sevoflurane: 39.3 (9.0); P=0.008] and after 35 min [xenon: 31.4 (6.6) vs sevoflurane: 37.0 (6.8); P=0.012]. During anaesthesia, aepEX values correlated with the clinical evaluation of depth of anaesthesia (e.g. >20% changes of the baseline arterial pressure or heart rate, spontaneous breathing and/or intolerance of mechanical ventilation, coughing, abdominal pressing, sweating, eye tearing).

CONCLUSIONS

We found the aepEX monitor to provide index in the range of adequate depth of xenon anaesthesia, when combined with remifentanil infusion in intubated patients undergoing elective abdominal surgery.

Performance of cardiac output measurement derived from arterial pressure waveform analysis in patients requiring high-dose vasopressor therapy

BACKGROUND

Arterial pressure waveform analysis of cardiac output (APCO) without external calibration (FloTrac/Vigileo™) is critically dependent upon computation of vascular tone that has necessitated several refinements of the underlying software algorithms. We hypothesized that changes in vascular tone induced by high-dose vasopressor therapy affect the accuracy of APCO measurements independently of the FloTrac software version.

METHODS

In this prospective observational study, we assessed the validity of uncalibrated APCO measurements compared with transpulmonary thermodilution cardiac output (TPCO) measurements in 24 patients undergoing vasopressor therapy for the treatment of cerebral vasospasm after subarachnoid haemorrhage.

RESULTS

Patients received vasoactive support with [mean (sd)] 0.53 (0.46) µg kg(-1) min(-1) norepinephrine resulting in mean arterial pressure of 104 (14) mm Hg and mean systemic vascular resistance of 943 (248) dyn s(-1) cm(-5). Cardiac output (CO) data pairs (158) were obtained simultaneously by APCO and TPCO measurements. TPCO ranged from 5.2 to 14.3 litre min(-1), and APCO from 4.1 to 13.7 litre min(-1). Bias and limits of agreement were 0.9 and 2.5 litre min(-1), resulting in an overall percentage error of 29.6% for 68 data pairs analysed with the second-generation FloTrac(®) software and 27.9% for 90 data pairs analysed with the third-generation software. Precision of the reference technique was 2.6%, while APCO measurements yielded a precision of 29.5% and 27.9% for the second- and the third-generation software, respectively. For both software versions, bias (TPCO-APCO) correlated inversely with systemic vascular resistance.

CONCLUSIONS

In neurosurgical patients requiring high-dose vasopressor support, precision of uncalibrated CO measurements depended on systemic vascular resistance. Introduction of the third software algorithm did not improve the insufficient precision (>20%) for APCO measurements observed with the second software version.

[Current developments in xenon research. Importance for anesthesia and intensive care medicine]

The noble gas xenon exerts favorable anesthetic properties along with remarkable hemodynamic stability in healthy patients undergoing elective surgery. It represents the nearly ideal anesthetic and provides safe and well controllable anesthesia although the exact mechanism by which xenon produces anesthesia remains to be elucidated. In addition xenon offers organ protective properties for vital organs including the brain, heart and kidneys which seem to be synergistic when used in combination with therapeutic hypothermia. As the high cost of xenon will probably preclude its wider use as a routine anesthetic, data from extensive tests in large numbers of high risk patients is needed to confirm its possible superiority in this setting.

Effect of TachoSil in a coagulopathic pig model with blunt liver injuries

OBJECTIVE

In this study, we investigated the efficacy of a fibrinogen/thrombin-coated collagen patch (TachoSil) to terminate severe bleeding in a coagulopathic pig model with blunt liver injury.

METHODS

Following surgical preparation, which included splenectomy and cystotomy, coagulopathy was induced by exchanging 80% of the animal's blood volume with hydroxyethylstarch 130/0.4 and lactated Ringer's solution. Subsequently, a grade III liver injury was induced by a force of 238 ± 19 Newton and free bleeding was allowed for 30 s. Animals were randomly assigned to receive either a placebo patch (cotton patch) (control group, n = 7) or a fibrinogen/thrombin patch (FT patch group, n = 7), which was positioned 30 s after injury on the inflicted area. Coagulation parameters, hemodynamic variables, as well as treatment were monitored for 2 h post-injury and patch placement. Histology was obtained to evaluate the equality of liver injury and to show the morphology of the FT patch.

RESULTS

Hemostasis after hemodilution was severely impaired. Blood loss after trauma was significantly diminished in the FT patch group (419 mL ± 90 mL) compared with the control group (1775 mL ± 358 mL) (P < 0.001). All animals treated with the FT patch survived, whereas 100% of the control group died before reaching the end of the observation period (P < 0.001). Gross sectioning and histology showed an equal degree of injury with a tight adherence of the FT patch.

CONCLUSION

TachoSil under severe coagulopathy effectively controlled bleeding and successfully prevented hemorrhagic death.

Xenon: recent developments and future perspectives

The noble gas xenon exerts favorable anesthetic properties along with remarkable hemodynamic stability in healthy patients undergoing elective surgery. Recent investigations documented that it does not prolong the duration of widely used neuromuscular blocking agents, including mivacurium and rocuronium. Some studies also suggest reduced neurocognitive compromise in the very early phase after general anesthesia. These properties differ from those observed for conventional inhalational anesthetics like isoflurane, desflurane and sevoflurane. However, a wider use of xenon in daily clinical routine has been limited owing to its higher price and technical restraints regarding economic delivery. Although there are controversial opinions, xenon seems to exert its main anesthetic features via the glutamate receptor. Recently, a novel binding cavity on the NMDA-subtype glutamate receptor has been elucidated that is occupied by xenon as well as isoflurane. Studies utilizing advanced imaging technologies have furthermore revealed that xenon markedly suppresses cerebral blood flow and glucose metabolism in distinct regions of the human brain. These investigations promise to further the understanding of the basic mechanisms underlying the induction and maintenance of anesthesia in general. Results from in vitro studies and various animal models have consistently demonstrated organoprotective properties of xenon, mainly in settings of ischemia and reperfusion injury. Interestingly, these effects have frequently been observed at subanesthetic concentrations and seem to be synergistic when used in combination with therapeutic hypothermia. Future studies will have to prove whether the high costs of xenon administration might be outweighed by its ability to substantially reduce the sequelae of myocardial and cerebral ischemia.

A comparison of waste gas concentrations during xenon or nitrous oxide anaesthesia

BACKGROUND AND OBJECTIVE

The aim of this study was to compare waste gas concentrations during xenon or nitrous oxide anaesthesia.

METHODS

A total of 64 patients were included in this study. Gas concentrations were measured with a mass spectrometer during anaesthesia. The probes were taken beside the patient's head and thorax and at a height of 180 cm above and at the floor level.

RESULTS

In both groups, waste gas concentrations peak after intubation and extubation. Waste gas levels during xenon anaesthesia are low compared with nitrous oxide.

CONCLUSIONS

The low waste gas levels of xenon seem to be beneficial compared to nitrous oxide.

Xenon alters right ventricular function

BACKGROUND

In contrast to other volatile anesthetics, xenon produces less cardiovascular depression with fewer fluctuations of various hemodynamic parameters, but reduces cardiac output (CO) in vivo. Besides an increase in left ventricular afterload and reduction of heart rate, an impairment of the right ventricular function might be an additional pathophysiological mechanism for the reduction of CO. Therefore, we used an animal model to study the effects of xenon as a supplemental anesthetic on right ventricular function, especially right ventricular afterload.

METHODS

Right ventricular function was monitored with a volumetric pulmonary artery catheter in 11 pigs during general anesthesia with thiopental. Six animals received additional 70% (volume) xenon (equivalent to 0.55 MAC minimum alveolar concentration). Parameters for systolic function, afterload, and preload were calculated at baseline and during 50 min of xenon application, and in a corresponding control group. Significant differences were detected by multivariate analyses of variance for repeated measures.

RESULTS

Xenon reduced CO on average by 30% and increased pulmonary arterial elastance by 60%, which led to a reduction of the right ventricular ejection fraction by 25%. Whereas right ventricular preload remained stable, maximal slope of pulmonary artery pressure and the right ventricular elastance increased. No effect on the ratio of stroke work and end-diastolic volume was found.

CONCLUSION

The reduction in CO during xenon anesthesia was partly due to an impairment of the right ventricular function, mainly caused by an increased afterload, without an impairment of systolic ventricular function.

Emergence and early cognitive function in the elderly after xenon or desflurane anaesthesia: a double-blinded randomized controlled trial †

BACKGROUND

Postoperative cognitive impairment after general anaesthesia, especially in the elderly, is a well-recognized problem. Xenon, known to be an N-methyl-d-aspartate antagonist, may be advantageous. In this study, the early cognitive function in the elderly after general anaesthesia with xenon was compared with that after desflurane.

METHODS

After approval by the local ethical committee and after obtaining written informed consent, patients were enrolled in this randomized, double-blinded, controlled study. Thirty-eight patients (65-75 yr old, ASA status I-III) undergoing an elective surgery with a planned duration of 60-180 min were allocated to either the xenon (n = 18) or the desflurane (n = 20) anaesthesia group. The primary outcome was the cognitive Test for Attentional Performance (TAP) with its subtests Alertness, Divided Attention, and Working Memory. After baseline assessment 12-24 h before operation, patients were followed-up 6-12 and 66-72 h after operation. Secondary outcomes were emergence times from anaesthesia and the modified Aldrete score.

RESULTS

No difference was found between the groups in the TAP at 6-12 and 66-72 h after operation. In the xenon group, emergence time was significantly faster for the following parameters: time to open eyes (P = 0.001), to react on demand (P = 0.001), to extubation (P = 0.001), and for time and spatial orientation (P = 0.007). The modified Aldrete score was significantly higher after 30, 45 and 60 min in the xenon group.

CONCLUSIONS

There was no difference in the postoperative cognitive testing at 6-12 and 66-72 h. Xenon was associated in the elderly with a faster emergence from general anaesthesia than desflurane.