Comparison of Force Distribution during Laryngoscopy with the C-MAC D-BLADE and Macintosh-Style Blades: A Randomised Controlled Clinical Trial.

Background: The geometry of a laryngoscope's blade determines the forces acting on the pharyngeal structures to a relevant degree. Knowledge about the force distribution along the blade may prospectively allow for the development of less traumatic blades. Therefore, we examined the forces along the blades experienced during laryngoscopy with the C-MAC D-BLADE and blades of the Macintosh style. We hypothesised that lower peak forces are applied to the patient's pharyngeal tissue during videolaryngoscopy with a C-MAC D-BLADE compared to videolaryngoscopy with a C-MAC Macintosh-style blade and direct laryngoscopy with a Macintosh-style blade. Beyond that, we assumed that the distribution of forces along the blade differs depending on the respective blade's geometry. Methods: After ethical approval, videolaryngoscopy with the D-BLADE or the Macintosh blade, or direct laryngoscopy with the Macintosh blade (all KARL STORZ, Tuttlingen, Germany), was performed on 164 randomly assigned patients. Forces were measured at six positions along each blade and compared with regard to mean force, peak force and spatial distribution. Furthermore, the duration of the laryngoscopy was measured. Results: Mean forces (all p < 0.011) and peak forces at each sensor position (all p < 0.019) were the lowest with the D-BLADE, whereas there were no differences between videolaryngoscopy and direct laryngoscopy with the Macintosh blades (all p > 0.128). With the D-BLADE, the forces were highest at the blade's tip. In contrast, the forces were more evenly distributed along the Macintosh blades. Videolaryngoscopy took the longest with the D-BLADE (p = 0.007). Conclusions: Laryngoscopy with the D-BLADE resulted in significantly lower forces acting on pharyngeal and laryngeal tissue compared to Macintosh-style blades. Interestingly, with the Macintosh blades, we found no advantage for videolaryngoscopy in terms of force application.

Comparative usability of manual defibrillators - A human factors study.

Background: A manual defibrillator represents key equipment for resuscitation of cardiac arrest scenario. Improper or slow operation of a defibrillator may adversely affect acute care. A self-explanatory interface facilitates handling and decreases the risk of operating errors. Therefore, we evaluated the usability of four commercially available defibrillators. Methods: 31 medical students executed 15 consecutive tasks on each defibrillator (Physio-Control Lifepak 20e, Schiller Defigard Touch 7, Corpuls 3 and Zoll X-Series). The operators' gaze was measured via eye-tracking and frequencies of required assistances and task completion times were recorded. Additionally, subjective perception of usability was assessed by a standardized questionnaire. Results: Least assistances (16) were required when operating the Lifepak 20e and most (63) when operating the X-Series. Cumulative task completion times were shortest in the Lifepak 20e (124 ± 31 s), followed by the Corpuls 3 (220 ± 69 s), the Defigard Touch 7 (225 ± 81 s) and the X-Series (289 ± 85 s; p < 0.001). Completion times of specific tasks differed considerably between the devices. Eye-tracking revealed associated interface issues that impeded the operators' performance. Overall standardized usability was rated best for the Lifepak 20e (81 ± 15) and worst for the X-Series (44 ± 20). Conclusions: The usability of defibrillators differs considerably and task specifically between devices. Interface issues of tasks impaired the operators' efficiency specifically. The perceived usability and the perceived stress-level after operating the devices corresponded with objective measures of usability. Eliminating specific usability issues may improve the operator's performance and, as a consequence patient outcome.

Residual anti-Xa activity in plasma of patients presenting for electively planned neuraxial regional anesthesia.

OBJECTIVE: To determine the incidence of increased anti-Xa activity within plasma levels 24 hours after administration of therapeutic dose low-molecular-weight heparin in patients presenting for elective neuraxial anesthesia. BACKGROUND: Guidelines for neuroaxial regional anesthesia for patients with antithrombotic drugs recommend time intervals for waiting. There is scientific evidence to suggest that the recommended interval of 24 hours may be insufficient in patients treated with therapeutic dose low-molecular-weight heparin. METHODS: Retrospective cohort analysis of 74 patients who received therapeutic dose low-molecular-weight heparin before planned neuraxial anesthesia between April 1, 2015 and April 1, 2020 at Freiburg University Hospital. Primary endpoint was the occurrence of elevated plasma anti-Xa levels in prophylactic range or higher (>0.2 IU/mL) 24 hours after the last application of the therapeutic dose. RESULTS: 24 hours after the last dose of therapeutic low-molecular-weight heparin, 18.0% of patients had elevated anti-Xa activity levels >0.2 IU/mL. A weak correlation between the time since the last administration of low-molecular-weight heparin and plasma anti-Xa levels could be found. No other risk factors were seen. CONCLUSIONS: Relevant residual anticoagulant activity, as measured by plasma anti-Xa levels within a prophylactic range, is measurable 24 hours after the last administration of therapeutic dose low-molecular-weight heparin. TRIAL REGISTRATION NUMBER: German Clinical Trials Register DRKS00022099.

Dental Strain on Maxillary Incisors During Tracheal Intubation With Double-Lumen Tubes and Different Laryngoscopy Techniques - A Blinded Mannequin Study.

OBJECTIVES: To quantify dental forces during double-lumen tube intubations with different laryngoscopy techniques. DESIGN: Experimental biomechanical mannequin study. SETTING: Two German university hospitals. PARTICIPANTS: One hundred four anesthesiologists with varying levels of experience. INTERVENTIONS: Participants performed a sequence of intubations on a mannequin equipped with hidden forces sensors in the maxillary incisors. Different laryngoscopy techniques were evaluated under normal and difficult airway conditions. Direct laryngoscopy was compared with different videolaryngoscopy techniques: the C-MAC with a Macintosh blade, the GlideScope, and the KingVision with hyperangulated blades. MEASUREMENTS AND MAIN RESULTS: A total of 624 intubations were evaluated. In normal airway conditions, the median (interquartile range [range]) peak forces were significantly lower when the GlideScope (15.7 (11.3-22.0 [2.1-110.5]) N) was used compared with direct laryngoscopy (21.0 (14.1-28.5[4.7-168.6]) N) (p = 0.007). In difficult airways, resulting forces were reduced using hyperangulated videolaryngoscopes (GlideScope: -13.7 N [p < 0.001]; KingVision: -11.9 N [p < 0.001]) compared with direct laryngoscopy, respectively. The time to intubation was prolonged with the use of the KingVision (25.5 (17.1-41.9[9.2-275.0])s [p < 0.001]) in comparison to direct laryngoscopy (20.8 (15.9-27.4[8.7-198.6]) s). The C-MAC demonstrated the shortest time to intubation. CONCLUSIONS: Although hyperangulated videolaryngoscopes improve dental strain, clinicians also should consider the time to intubation, which is shortest with nonhyperangulated videoblades, when choosing a laryngoscopy technique on an individual patient basis.

Anaesthesia protocol evaluation of the videolaryngoscopy with the McGrath MAC and direct laryngoscopy for tracheal intubation in 1000 patients undergoing rapid sequence induction: the randomised multicentre LARA trial study protocol.

INTRODUCTION: Rapid sequence induction of anaesthesia is indicated in patients with an increased risk of pulmonary aspiration. The main objective of the technique is to reduce the critical time period between loss of airway protective reflexes and rapid inflation of the cuff of the endotracheal tube to minimise the chance of aspiration of gastric contents. The COVID-19 pandemic has reinforced the importance of first-pass intubation success to ensure patient and healthcare worker safety. The aim of this study is to compare the first-pass intubation success rate (FPS) using the videolaryngoscopy compared with conventional direct laryngoscopy in surgical patients with a high risk of pulmonary aspiration. METHODS AND ANALYSIS: The LARA trial is a multicentre, patient-blinded, randomised controlled trial. Consecutive patients requiring tracheal intubation are randomly allocated to either the McGrath MAC videolaryngoscope or direct laryngoscopy using the Macintosh laryngoscope. The expected rate of FPS is 92% in the McGrath group and 82% in the Macintosh group. Each group must include a total of 500 patients to achieve 90% power for detecting a difference at the 5% significance level. Successful intubation with the FPS is the primary endpoint. The secondary endpoints are the time to intubation, the number of intubation attempts, the necessity of airway management alternatives, the visualisation of the glottis using the Cormack and Lehane Score and the Percentage Of Glottic Opening Score and definite adverse events. ETHICS AND DISSEMINATION: The project is approved by the local ethics committee of the Medical Association of the Rhineland Palatine state (registration number: 2020-15502) and medical ethics committee of the University of Freiburg (registration number: 21-1303). The results of this study will be made available in form of manuscripts for publication and presentations at national and international meetings. TRIAL REGISTRATION: NCT04794764.

Incidence of gastric insufflation at high compared with low laryngeal mask cuff pressure: A randomised controlled cross-over trial.

BACKGROUND: The success of ventilation with a laryngeal mask depends crucially on the seal between the mask and the periglottic tissue. Increasing the laryngeal mask's cuff volume is known to reduce oral air leakage but may lead to gastric insufflation. OBJECTIVE: We hypothesised that a lower cuff pressure would result in less gastric insufflation. We sought to compare gastric insufflation with laryngeal mask cuff pressures of 20 cmH2O (CP20) and 60 cmH2O (CP60) during increasing peak airway pressures in a randomised controlled double-blind cross-over study. We also evaluated the incidence of gastric insufflation at the recommended peak airway pressure of 20 cmH2O or less and during both intermittent positive airway pressure and continuous positive airway pressure. METHODS: After obtaining ethics approval and written informed consent, 184 patients ventilated via laryngeal mask received a stepwise increase in peak airway pressure from 15 to 30 cmH2O with CP20 and CP60 in turn. Gastric insufflation was determined via real-time ultrasound and measurement of the cross-sectional area of the gastric antrum. The primary endpoint was the incidence of gastric insufflation at the different laryngeal mask cuff pressures. RESULTS: Data from 164 patients were analysed. Gastric insufflation occurred less frequently at CP20 compared with CP60 (P < 0.0001). Gastric insufflation was detected in 35% of cases with CP20 and in 48% with CP60 at a peak airway pressure of 20 cmH2O or less. Gastric insufflation occurred more often during continuous than during intermittent positive airway pressures (P < 0.01). CONCLUSION: A laryngeal mask cuff pressure of 20 cmH2O may reduce the risk of gastric insufflation during mechanical ventilation. Surprisingly, peak airway pressure of 20 cmH2O or less may already induce significant gastric insufflation. Continuous positive airway pressure should be avoided due to an increased risk of gastric insufflation. CLINICAL TRIAL REGISTRATION: The study was registered in the German Clinical Trials Register (DRKS00010583) https://www.drks.de.

Dislodgement Forces and Cost Effectiveness of Dressings and Securement for Peripheral Intravenous Catheters: A Randomized Controlled Trial.

OBJECTIVES: Peripheral intravenous catheters (PIVC) are the most frequently used invasive devices in medicine. PIVC failure before treatment completion is a significant concern and occurs in 33-69% of patients. Partial dislodgement and accidental removal are some of the reasons for PIVC failure. The most effective dressing and securement method for preventing accidental removal remains unclear. It was the aim of this study to compare the force required to dislodge a PIVC with four commonly used dressing and securement methods. Additionally, costs were calculated. METHODS: Truncated 18-gauge i.v. cannulas were attached onto the forearm of 209 volunteers using four different dressings and securements (sterile absorbent wound dressing covered by two different types of elastic polyester fleece, bordered and non-bordered polyurethane). The force during continuously stronger pulling until dislodgement was recorded. RESULTS: The highest resistance against dislodgement forces could be observed with a sterile absorbent wound dressing covered by two incised elastic polyester fleece dressings. Commercially-manufactured bordered and non-bordered polyurethan film dressings were 20% to 75% more expensive than sterile absorbent wound dressings covered by elastic polyester fleece dressing. CONCLUSIONS: Elastic polyester fleece secured a PIVC against accidental removal by external force best, compared to commercially-manufactured bordered and non-bordered polyurethane film dressing.

LMA Gastro™ airway is feasible during upper gastrointestinal interventional endoscopic procedures in high risk patients: a single-center observational study.

BACKGROUND: Nonoperating room anesthesia during gastroenterological procedures is a growing field in anesthetic practice. While the numbers of patients with severe comorbidities are rising constantly, gastrointestinal endoscopic interventions are moving closer to minimally invasive endoscopic surgery. The LMA Gastro™ is a new supraglottic airway device, developed specifically for upper gastrointestinal endoscopy and interventions. The aim of this study was to evaluate the feasibility of LMA Gastro™ in patients with ASA physical status ≥3 undergoing advanced endoscopic procedures. METHODS: We analyzed data from 214 patients retrospectively who received anesthesia for gastroenterological interventions. Inclusion criteria were upper gastrointestinal endoscopic interventions, airway management with LMA Gastro™ and ASA status ≥3. The primary outcome measure was successful use of LMA Gastro™ for airway management and endoscopic intervention. RESULTS: Thirtyone patients with ASA physical status ≥3, undergoing complex and prolonged upper gastrointestinal endoscopic procedures were included. There were 7 endoscopic retrograde cholangiopancreatographies, 7 peroral endoscopic myotomies, 5 percutaneous endoscopic gastrostomies and 12 other complex procedures (e.g. endoscopic submucosal dissection, esophageal stent placement etc.). Of these, 27 patients were managed successfully using the LMA Gastro™. Placement of the LMA Gastro™ was reported as easy. Positive pressure ventilation was performed without difficulty. The feasibility of the LMA Gastro™ for endoscopic intervention was rated excellent by the endoscopists. In four patients, placement or ventilation with LMA Gastro™ was not possible. CONCLUSIONS: We demonstrated the feasibility of the LMA Gastro™ during general anesthesia for advanced endoscopic procedures in high-risk patients. TRIAL REGISTRATION: German Clinical Trials Register (DRKS00017396) Date of registration: 23rd May 2019, retrospectively registered.

Comprehensive evaluation of manikin-based airway training with second generation supraglottic airway devices.

BACKGROUND: Supraglottic airway devices (SADs) are an essential second line tool during difficult airway management after failed tracheal intubation. Particularly for such challenging situations the handling of an SAD requires sufficient training. We hypothesized that the feasibility of manikin-based airway management with second generation SADs depends on the type of manikin. METHODS: Two airway manikins (TruCorp AirSim® and Laerdal Resusci Anne® Airway Trainer™) were evaluated by 80 experienced anesthesia providers using 5 different second generation SADs (LMA® Supreme™ [LMA], Ambu® AuraGain™, i-gel®, KOO™-SGA and LTS-D™). The primary outcome of the study was feasibility of ventilation measured by assessment of the manikins' lung distention. As secondary outcome measures, oropharyngeal leakage pressure (OLP), ease of gastric tube insertion the insertion time, position and subjective assessments were evaluated. RESULTS: Ventilation was feasible with all combinations of SAD and manikin. By contrast, an OLP exceeding 10 cm H2O could be reached with most of the SADs in the TruCorp but with the LTS-D only in the Laerdal manikin. Gastric tube insertion was successful in above 90% in the Laerdal vs 87% in the TruCorp manikin (P<0.009). Insertion times differed significantly between manikins. The SAD positions were better in the Laerdal manikin for LMA, Ambu, i-gel and LTS-D. Participant's assessments were superior in the Laerdal manikin for LMA, Ambu, i-gel and KOO-SGA. CONCLUSIONS: Ventilation is possible with all combinations. However, manikins are variable in their ability to adequately represent additional functions of second generation SADs. In order to achieve the best performance during training, the airway manikin should be chosen depending on the SAD in question.

Protocol based evaluation for feasibility of extubation compared to clinical scoring systems after major oral cancer surgery safely reduces the need for tracheostomy: a retrospective cohort study.

BACKGROUND: Despite risks, complications and negative impact to quality of life, tracheostomy is widely used to bypass upper airway obstruction after major oral cancer surgery (MOCS). Decision to tracheostomy is frequently based on clinical scoring systems which mainly have not been validated by different cohorts. Delayed extubation in the Intensive Care Unit (ICU) may be a suitable alternative in selected cases. We hypothesize that delayed routine ICU extubation after MOCS instead of scoring system based tracheostomy is safe, feasible and leads to lower tracheostomy rates. METHODS: We retrospectively analyzed our clinical protocol which provides routine extubation of patients after MOCS in the ICU. The primary outcome measure was a composite of early reintubation within 24 h or secondary tracheostomy. Secondary outcome measures included airway obstruction related morbidity and mortality. Predictor variables included tumor localisation, surgical procedure and reconstruction method, length of operation and pre-existing morbidity. Furthermore we assessed the ability of four clinical scoring systems to identify patients requiring secondary tracheostomy. Statistical processing includes basic descriptive statistics, Chi-squared test and multivariate logistic regression analysis. RESULTS: Two hundred thirty four cases were enclosed to this retrospective study. Fourteen patients (6%) required secondary tracheostomy, Ten patients (4%) required reintubation within 24 h after extubation. No airway obstruction associated mortality, morbidity and cannot intubate cannot ventilate situation was observed. Seventy five percent of the patients were extubated within 17 h after ICU admission. All evaluated scores showed a poor positive predictive value (0.08 to 0.18) with a sensitivity ranged from 0.13 to 0.63 and specificity ranged from 0.5 to 0.93. CONCLUSIONS: Our data demonstrate that common clinical scoring systems fail to prevent tracheostomy in patients after MOCS. Application of scoring systems may lead to a higher number of unnecessary tracheostomies. Delayed routine extubation in the ICU after MOCS seems an appropriate and safe approach to avoid tracheostomy and the related morbidity.

Acquired von Willebrand syndrome and impaired platelet function during venovenous extracorporeal membrane oxygenation: Rapid onset and fast recovery.

BACKGROUND: Bleeding contributes to the high mortality of venovenous extracorporeal membrane oxygenation (vvECMO). The development of acquired von Willebrand syndrome (AVWS) has been identified as relevant pathology during ECMO. This study was performed to determine the onset of AVWS after implantation and the recovery of von Willebrand factor (VWF) parameters after explantation of ECMO in a large cohort of patients. METHODS: VWF parameters of 59 patients treated with vvECMO at a university ECMO center were obtained before ECMO implantation, during therapy, and after explantation. In a subgroup of patients, light transmission aggregometry of platelets and flow-cytometric quantification of platelet granule secretion were performed. RESULTS: All patients developed severe AVWS hours after implantation of vvECMO. After explantation, AVWS recovered within 3 hours in 60%, within 6 hours in 86%, and in all patients within 1 day. Aggregometry showed hypoaggregability of platelets after stimulation with ADP, ristocetin, collagen, and epinephrine. Flow-cytometric platelet analyses revealed severely reduced expression of CD62 and CD63. CONCLUSIONS: All patients during vvECMO support rapidly develop AVWS and platelet dysfunction, resulting in severe impairment of coagulation. After explantation, AVWS overwhelmingly recovers within hours, resulting in a hypercoagulative state. These findings augment the need for novel extracorporeal technologies with reduced shear stress, and shift the emphasis for intense anti-coagulation during ECMO instead to a time-point after explantation.

Bleeding during veno-venous ECMO cannot reliably be predicted by rotational thrombelastometry (ROTEM™).

INTRODUCTION: Veno-venous extracorporeal membrane oxygenation (vvECMO) used for respiratory support is associated with clinical bleeding in at least one third of patients. Mechanisms promoting bleeding, like acquired von Willebrand syndrome, cannot be identified by routine coagulation tests. This study was performed to evaluate rotational Thrombelastography (ROTEM™) for specific results predicting bleeding events during vvECMO. METHODS: Five hundred and thirty-four ROTEM™ analyses of 57 patients over 574 days have been evaluated. Patients were graded into three groups according to the severity of bleeding, following the Freiburg ECMO bleeding assessment. ROTEM™ results and basic as well as comprehensive laboratory coagulation tests have been compared among the three groups and overall between defined time points. RESULTS: Fourteen patients (25 %) presented without bleeding, 22 patients (39 %) showed mild bleeding and 21 patients (36 %) became evident with relevant clinical bleeding. No bleeding shock and no fatal bleeding event occurred. No case of hyperfibrinolysis was observed. Neither a statistical difference for ECMO blood flow nor duration of therapy among the groups could be shown. The only significant difference was clotting time (CT) in the InTEM analysis, with a median (IQR) of 175 (37.5) seconds in Group 1, 190 (54.5) seconds in Group 2 and 204 (90) seconds in Group 3. When comparing overall ROTEM™ analyses between defined time points, continuous worsening of CT can be found in ExTEM, FibTEM and ApTEM. Reduced A10, A20 and congruently maximum clot firmness, especially, developed in ExTEM and ApTEM and with a minor characteristic in InTEM, but not in FibTEM. ROTEM™ and coagulation-parameter results before 19 clinical relevant bleeding episodes compared to all other results only showed differences in FibTEM. CONCLUSION: ROTEM™ as a functional viscoelastic analysis does not provide additional information to basic and comprehensive laboratory tests during vvECMO. Bleeding events cannot be predicted by the means of specific ROTEM™ results.

Feasibility of a Supraglottic Airway Device for Transbronchial Lung Cryobiopsy-A Retrospective Analysis.

OBJECTIVES: To determine the feasibility of a supraglottic airway device for transbronchial cryobiopsy in adults. DESIGN: Retrospective analysis of anesthetic and pulmonary records between March 2015 and August 2016. SETTING: Single university medical center. PARTICIPANTS: One hundred thirty-two patients who underwent transbronchial cryobiopsy procedures performed under general anesthesia. INTERVENTIONS: Not applicable. MEASUREMENTS AND MAIN RESULTS: Failure-free use of a supraglottic airway device was 96.8%. Failure of supraglottic airway device insertion was 3.1% because of impossible placement (n = 1), high oropharyngeal leakage (n = 1), massive bleeding requiring bronchial blocker (n = 1), and acute right heart failure with cardiac arrest requiring resuscitation (n = 1). No serious adverse events due to the supraglottic airway device were observed. CONCLUSION: The data demonstrated that transbronchial cryobiopsy under general anesthesia and airway management with a supraglottic airway device was a feasible technique.

An easy-to-build, low-budget point-of-care ultrasound simulator: from Linux to a web-based solution.

BACKGROUND: Hands-on training in point-of-care ultrasound (POC-US) should ideally comprise bedside teaching, as well as simulated clinical scenarios. High-fidelity phantoms and portable ultrasound simulation systems are commercially available, however, at considerable costs. This limits their suitability for medical schools. A Linux-based software for Emergency Department Ultrasound Simulation (edus2TM) was developed by Kulyk and Olszynski in 2011. Its feasibility for POC-US education has been well-documented, and shows good acceptance. An important limitation to an even more widespread use of edus2, however, may be due to the need for a virtual machine for WINDOWS® systems. Our aim was to adapt the original software toward an HTML-based solution, thus making it affordable and applicable in any simulation setting. METHODS: We created an HTML browser-based ultrasound simulation application, which reads the input of different sensors, triggering an ultrasound video to be displayed on a respective device. RFID tags, NFC tags, and QR Codes™ have been integrated into training phantoms or were attached to standardized patients. The RFID antenna was hidden in a mock ultrasound probe. The application is independent from the respective device. RESULTS: Our application was used successfully with different trigger/scanner combinations and mounted readily into simulated training scenarios. The application runs independently from operating systems or electronic devices. CONCLUSION: This low-cost, browser-based ultrasound simulator is easy-to-build, very adaptive, and independent from operating systems. It has the potential to facilitate POC-US training throughout the world, especially in resource-limited areas.

Is Extracorporeal CO2 Removal Really "Safe" and "Less" Invasive? Observation of Blood Injury and Coagulation Impairment during ECCO2R.

Extracorporeal CO2 removal (ECCO2R) is promoted with attributes like "safe" and "less invasive" compared with (high-flow) venovenous extracorporeal membrane oxygenation (ECMO) systems. With our experience in coagulation disorders during ECMO therapy with this observational study, we for the first time prospectively evaluate hemolysis and coagulation disorders during ECCO2R. Eight consecutive patients with predominant hypercapnic respiratory failure were treated with the Hemolung respiratory assist system (Alung-Technologies, Pittsburg, PA). Bleeding as well as changes of coagulation parameters was prospectively assessed. Overall therapy was observed in seven patients with 52 treatment days. In four of seven patients (57%), relevant clinical bleeding symptoms occurred. Thrombocytopenia, hemolysis, factor XIII deficiency and acquired von Willebrand syndrome (loss of high-molecular-weight von Willebrand factor multimers) were typical findings, and the patients spontaneously recovered after discontinuation of the extracorporeal system. In one patient, extracorporeal system stopped because of thrombotic occlusion. Six of seven patients required transfusion of red blood cells. Our observation shows that even low-flow extracorporeal lung support is associated with relevant clinical bleeding symptoms, blood cell injury, development of acquired von Willebrand syndrome and need for transfusion. In our opinion, it therefore is too early to quote ECCO2R "safe" and "less invasive."

Venovenous Extracorporeal Membrane Oxygenation With Prophylactic Subcutaneous Anticoagulation Only: An Observational Study in More Than 60 Patients.

Extracorporeal lung support and therapeutic anticoagulation are dogmatically linked for most clinicians in fear of clotting of the extracorporeal circuit. In the last decade, however, we have learned that bleeding complications in the course of extracorporeal membrane oxygenation (ECMO) therapy are common and not occasionally limiting or fatal. Even though international guidelines lowered the PTT-target values, ECMO therapy without anticoagulation has only been reported sporadically in case reports heretofore. This monocentric, observational study was designed to evaluate a protocol for venovenous ECMO therapy without additional anticoagulation. Patients without former thrombotic events solely received thrombosis prophylaxis with 40 mg subcutaneous enoxaparin per day like every critical care patient. After approval by the local ethics committee (Albert-Ludwigs-University Freiburg ethics committee, EK 513/14) all consecutive patients treated with venovenous ECMO therapy since introduction of the protocol have been identified. Digital charts of the patients have been evaluated with special regard to bleeding and thrombotic or embolic events or breakdown of the extracorporeal circuit. Sixty-one patients received venovenous ECMO therapy with prophylactic subcutaneous enoxaparin only. Median duration of ECMO therapy was 7 days (2-32). Overall 560 ECMO days have been observed. No system exchange because of thrombotic occlusion was necessary within the permitted 5 days run time of the centrifugal pump. Overall we identified thrombotic complications in four patients. In three of them centrifugal pump after a runtime of more than 5 days unexpectedly stopped completely because of thrombotic occlusion. In all cases pump exchange was performed promptly and patients did not incur hypoxic deficit. One other patient received substitution of blood products and coagulation factor concentrates because of severe bleeding and sustained myocardial infarction the day after. Only 18% of patients presented with essential clinical bleeding after 7 days of therapy. No fatal bleeding event and no intracranial hemorrhage was observed. Patients required only a third of blood product transfusion compared to published data. Venovenous ECMO therapy with prophylactic anticoagulation only was feasible in this study. It was not associated with an increased rate of system exchanges compared to regimes with therapeutic anticoagulation in registry data. It provides the potential to relevantly decrease the incidence of severe bleeding events and blood transfusion requirements. The apodictic adherence to anticoagulation in therapeutic dosage should be critically scrutinized in every patient.