Less-invasive subdural electrocorticography for investigation of spreading depolarizations in patients with subarachnoid hemorrhage.

Introduction: Wyler-strip electrodes for subdural electrocorticography (ECoG) are the gold standard for continuous bed-side monitoring of pathological cortical network events, such as spreading depolarizations (SD) and electrographic seizures. Recently, SD associated parameters were shown to be (1) a marker of early brain damage after aneurysmal subarachnoid hemorrhage (aSAH), (2) the strongest real-time predictor of delayed cerebral ischemia currently known, and (3) the second strongest predictor of patient outcome at 7 months. The strongest predictor of patient outcome at 7 months was focal brain damage segmented on neuroimaging 2 weeks after the initial hemorrhage, whereas the initial focal brain damage was inferior to the SD variables as a predictor for patient outcome. However, the implantation of Wyler-strip electrodes typically requires either a craniotomy or an enlarged burr hole. Neuromonitoring via an enlarged burr hole has been performed in only about 10% of the total patients monitored. Methods: In the present pilot study, we investigated the feasibility of ECoG monitoring via a less invasive burrhole approach using a Spencer-type electrode array, which was implanted subdurally rather than in the depth of the parenchyma. Seven aSAH patients requiring extraventricular drainage (EVD) were included. For electrode placement, the burr hole over which the EVD was simultaneously placed, was used in all cases. After electrode implantation, continuous, direct current (DC)/alternating current (AC)-ECoG monitoring was performed at bedside in our Neurointensive Care unit. ECoGs were analyzed following the recommendations of the Co-Operative Studies on Brain Injury Depolarizations (COSBID). Results: Subdural Spencer-type electrode arrays permitted high-quality ECoG recording. During a cumulative monitoring period of 1,194.5 hours and a median monitoring period of 201.3 (interquartile range: 126.1-209.4) hours per patient, 84 SDs were identified. Numbers of SDs, isoelectric SDs and clustered SDs per recording day, and peak total SD-induced depression duration of a recording day were not significantly different from the previously reported results of the prospective, observational, multicenter, cohort, diagnostic phase III trial, DISCHARGE-1. No adverse events related to electrode implantation were noted. Discussion: In conclusion, our findings support the safety and feasibility of less-invasive subdural electrode implantation for reliable SD-monitoring.

Laryngeal mask airway versus endotracheal tube for percutaneous dilatational tracheostomy in critically ill adults.

BACKGROUND: Percutaneous dilatational tracheostomy (PDT) is one of the most common bedside surgical procedures performed in critically ill adults, on intensive care units (ICUs), who require long-term ventilation. PDT is associated with relevant life-threatening complications: Cuff rupture or accidental extubation may lead to hypoxia, aspiration or loss of airway. Puncture of the oesophagus, or creating a false passage during dilatation or replacement of the tracheostomy tube, can lead to pneumothorax or emphysema. Wound infections may occur which can cause mediastinits, especially after creation of false passage or in early tracheotomized post-sternotomy patients after cardiac surgery. During the procedure, the patient's airway can be secured with an endotracheal tube (ETT) or a laryngeal mask airway (LMA). This is an updated version of the review first published in 2014. OBJECTIVES: To assess the safety and effectiveness of LMA versus ETT in critically ill adults undergoing PDT on the ICU. SEARCH METHODS: We searched the following databases to 9 January 2018: Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE and Embase. We searched for reports of ongoing trials in the metaRegister of Controlled Trials (mRCT). We handsearched for relevant studies in conference proceedings of five relevant annual congresses. We contacted study authors and experts concerning unpublished data and ongoing trials. We searched for further relevant studies in the reference lists of all included trials and of relevant systematic reviews. SELECTION CRITERIA: We included randomized controlled trials (RCTs) that compared use of laryngeal mask airways versus endotracheal tubes in critically ill adults undergoing elective PDT in the ICU, without injuries to or diseases of the face or neck. We imposed no restrictions with regard to language, timing or technique of PDT performed. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed the eligibility and methodological quality of each study and carried out data extraction. Our primary outcomes were all-cause mortality, procedure-related mortality and tally of participants with one or more serious adverse events. Where possible, we combined homogeneous studies for meta-analysis. We used Cochrane's 'Risk of bias' tool and used GRADE to assess the quality of evidence for key outcomes. MAIN RESULTS: We included nine RCTs in this review involving 517 participants.Studies had a high or unclear risk of bias. The main reason for this was low methodological quality or missing data, even after study authors were contacted. Study size was generally small, with a minimum of 40, and a maximum of 73 participants.In one study (40 participants), three deaths in the LMA group and two deaths in the ETT group were reported, although none of the deaths were related to the procedure (very low-quality evidence).Five studies (281 participants) reported on procedure-related deaths, stating that no procedure-related death occurred at all (very low-quality evidence).It is uncertain whether there is a difference in the number of people experiencing one or more serious adverse event(s) between LMA and ETT (risk ratio (RR) 0.86, 95% confidence interval (CI) 0.41 to 1.80; 467 participants, 8 studies, very low-quality evidence).The duration of the procedure may be shorter in the LMA group (mean difference (MD) -1.46 minutes, 95% CI -1.92 to -1.01 minutes; 6 studies, 324 participants, low-quality evidence).However failure of procedure, as allocated by randomization, requiring conversion to any other procedure, may be higher in the LMA group (RR 2.82, 95% CI 1.22 to 6.52; 8 studies, 439 participants, low-quality evidence).We did not find any clear evidence of a difference between ETT and LMA groups for all other outcomes. Only one study provided follow-up data for late complications related to the intervention, showing no clear evidence of benefit for any treatment group. AUTHORS' CONCLUSIONS: Evidence on the safety of LMA for PDT is too limited to allow conclusions to be drawn on either its efficacy or safety compared with ETT. Although the LMA procedure may shorten the period during which the airway is insecure, it may also lead to higher conversion rates. Also, late complications have not been investigated sufficiently. These results are primarily based on single-centre trials with small sample sizes, and therefore the level of evidence remains low. Studies with low risk of bias focusing on late complications and relevant patient-related outcomes are necessary for definitive conclusions on safety issues related to this procedure. The dependency of the successful placement of a LMA on the type of LMA used should also be further assessed.There are two studies awaiting classification that may alter the conclusions once assessed.

A radiographic comparison of human airway anatomy and airway manikins--Implications for manikin-based testing of artificial airways.

OBJECTIVE: The aim of this prospective, single-center, observational study was to investigate the accuracy of modeling and reproduction of human anatomical dimensions in manikins by comparing radiographic upper airway measurements of 13 different models with humans. METHODS: 13 commonly used airway manikins (male or female anatomy based) and 47 controls (adult humans, 37 male, 10 female) were investigated using a mediosagittal and axial cervical spine CT scan. For anatomical comparison six human upper airway target structures, the following were measured: Oblique diameter of the tongue through the center, horizontal distance between the center point of the tongue and the posterior pharyngeal wall, horizontal distance between the vallecula and the posterior pharyngeal wall, distance of the upper oesophageal orifice length of epiglottis distance at the narrowest part of the trachea. Furthermore, the cross-section of the trachea in axial view and the cross-section of the upper oesophageal orifice in the same section was calculated. All measurements were compared gender specific, if the gender was non-specified with the whole sample. RESULTS: None of the included 13 different airway manikins matched anatomy in human controls (n = 47) in all of the six measurements. The Laerdal Airway Management Trainer, however, replicated human airway anatomy at least satisfactorily. CONCLUSION: This investigation showed that all of the examined manikins did not replicate human anatomy. Manikins should therefore be selected cautiously, depending on the type of airway securing procedure. Their widespread use as a replacement for in vivo trials in the field of airway management needs to be reconsidered.

[Evidence-based Medicine online for young doctors - a randomised controlled trial]. / Evidenzbasierte Medizin online zum ärztlichen Berufsstart- eine randomisiert-kontrollierte Studie.

INTRODUCTION: Evidence-based Medicine (EbM) was originally developed as a teaching tool for young doctors, but in Germany the last surveys among residents in 2009 and 2011 demonstrated that, across all topics, the largest deficits were seen in the field of EbM. One reason may be a deficit in customised offers for continuing medical education in EbM. In a randomised controlled trial with a wait-control design we investigated a possible gain in knowledge and the acceptance of an online course in EbM for first-year residents. METHODS: All first-year residents at the Hospital of the Goethe University in Frankfurt received the offer to voluntarily take part in an online EbM course. The tutored course consisted of five modules according to the five steps of EbM, each module being complemented by practical tasks. The participants were randomised via telephone to the course right away or after a three-month waiting period. The primary endpoint (i.e., knowledge) was tested via two sets of 13 multiple choice questions before and after the course and after 6 and 12 months. The participants were asked to subjectively evaluate the course by using an A-F grading system and to semiquantitatively assess its level of difficulty; they were also asked to evaluate the usefulness of its content in their clinical setting. RESULTS: 114 out of the 120 randomised participants took part. After 3 months the immediate intervention group (n=58) achieved a median of 10 (95 % confidence interval 10 to 11) correct answers following the course, whereas the waiting intervention group only received a median of 4 (95% confidence interval 4 to 5) correct answers after the three month waiting period (p ≤ 0.0001). The median gain in knowledge for both groups throughout the course was 5 correct answers (p ≤ 0.0001), and this proved to remain constant within a twelve month period. Six months after the course, this course was rated as clinically useful by 96.4 % of the participants, and 38.1% stated that they would volunteer again in further teaching activities. The course received a median grade of B. DISCUSSION AND CONCLUSIONS: A German online EbM course for first-year residents leads to a remarkable and sustainable gain in knowledge, is well marked, and its contents were regarded as clinically relevant. This tutored practical course is applicable to various settings and could provide an important contribution to EbM residency programs.