German guidelines for airway management 2023.

The German airway management guidelines are intended to serve as an orientation and decision-making aid and thus contribute to the optimal care of patients undergoing anesthesiologic- and intensive medical care. As part of the pre-anesthesiologic evaluation, anatomical and physiological indications for difficult mask ventilation and intubation shall be evaluated. This includes the assessment of mouth opening, dental status, mandibular protrusion, cervical spine mobility and existing pathologies. The airway shall be secured while maintaining spontaneous breathing if there are predictors or anamnestic indications of difficult or impossible mask ventilation and/or endotracheal intubation. Various techniques can be used here. If there is an unexpectedly difficult airway, a video laryngoscope is recommended after unsuccessful direct laryngoscopy, consequently a video laryngoscope must be available at every anesthesiology workplace. The airway shall primarily be secured with a video laryngoscope in critically ill- and patients at risk of aspiration. Securing the airway using translaryngeal and transtracheal techniques is the "ultima ratio" in airway management. The performance or supervision of airway management in the intensive care unit is the responsibility of experienced physicians and nursing staff. Appropriate education and regular training are essential. Clear communication and interaction between team members are mandatory before every airway management procedure. Once the airway has been secured, the correct position of the endotracheal tube must be verified using capnography.

Comparison of forces acting on maxillary incisors during tracheal intubation with different laryngoscopy techniques: a blinded manikin study.

Dental trauma is a common complication of tracheal intubation. As existing evidence is insufficient to validly assess the impact of different laryngoscopy techniques on the incidence of dental trauma, the force exerted onto dental structures during tracheal intubation was investigated. An intubation manikin was equipped with hidden force sensors in all maxillary incisors. Dental force was measured while 104 anaesthetists performed a series of tracheal intubations using direct laryngoscopy with a Macintosh blade, and videolaryngoscopy with a C-MAC® , or the hyperangulated GlideScope® or KingVision® laryngoscopes in both normal and difficult airway conditions. A total of 624 tracheal intubations were analysed. The median (IQR [range]) peak force of direct laryngoscopy in normal airways was 21.1 (14.0-32.8 [2.3-127.6]) N and 29.3 (17.7-44.8 [3.3-97.2]) N in difficult airways. In normal airways, these were lower with the GlideScope and KingVision hyperangulated laryngoscopes, with a reduction of 4.6 N (p = 0.006) and 10.9 N (p < 0.001) compared with direct laryngoscopy, respectively. In difficult airways, these were lower with the GlideScope and KingVision hyperangulated laryngoscopes, with a reduction of 9.8 N (p < 0.001) and 17.6 N (p < 0.001) compared with direct laryngoscopy, respectively. The use of the C-MAC did not have an impact on the median peak force. Although sex of anaesthetists did not affect peak force, more experienced anaesthetists generated a higher peak force than less experienced providers. We conclude that hyperangulated videolaryngoscopy was associated with a significantly decreased force exerted on maxillary incisors and might reduce the risk for dental injury in clinical settings.

Correction to: Protective ventilation with high versus low positive end-expiratory pressure during one-lung ventilation for thoracic surgery (PROTHOR): study protocol for a randomized controlled trial.

After publication of the original article [1], the authors have notified us that two of the collaborator first and last names have been inverted in the "PROTHOR Investigators" table.

Protective ventilation with high versus low positive end-expiratory pressure during one-lung ventilation for thoracic surgery (PROTHOR): study protocol for a randomized controlled trial.

BACKGROUND: Postoperative pulmonary complications (PPC) may result in longer duration of in-hospital stay and even mortality. Both thoracic surgery and intraoperative mechanical ventilation settings add considerably to the risk of PPC. It is unclear if one-lung ventilation (OLV) for thoracic surgery with a strategy of intraoperative high positive end-expiratory pressure (PEEP) and recruitment maneuvers (RM) reduces PPC, compared to low PEEP without RM. METHODS: PROTHOR is an international, multicenter, randomized, controlled, assessor-blinded, two-arm trial initiated by investigators of the PROtective VEntilation NETwork. In total, 2378 patients will be randomly assigned to one of two different intraoperative mechanical ventilation strategies. Investigators screen patients aged 18 years or older, scheduled for open thoracic or video-assisted thoracoscopic surgery under general anesthesia requiring OLV, with a maximal body mass index of 35 kg/m2, and a planned duration of surgery of more than 60 min. Further, the expected duration of OLV shall be longer than two-lung ventilation, and lung separation is planned with a double lumen tube. Patients will be randomly assigned to PEEP of 10 cmH2O with lung RM, or PEEP of 5 cmH2O without RM. During two-lung ventilation tidal volume is set at 7 mL/kg predicted body weight and, during OLV, it will be decreased to 5 mL/kg. The occurrence of PPC will be recorded as a collapsed composite of single adverse pulmonary events and represents the primary endpoint. DISCUSSION: PROTHOR is the first randomized controlled trial in patients undergoing thoracic surgery with OLV that is adequately powered to compare the effects of intraoperative high PEEP with RM versus low PEEP without RM on PPC. The results of the PROTHOR trial will support anesthesiologists in their decision to set intraoperative PEEP during protective ventilation for OLV in thoracic surgery. TRIAL REGISTRATION: The trial was registered in clinicaltrials.gov ( NCT02963025 ) on 15 November 2016.

[Rapid sequence induction and intubation in patients with risk of aspiration : Recommendations for action for practical management of anesthesia]. / "Rapid sequence induction and intubation" beim aspirationsgefährdeten Patienten : Handlungsempfehlungen für das praktische anästhesiologische Management.

BACKGROUND: Induction of general anesthesia in patients with risk for aspiration needs special considerations to avoid the incidence and severity of complications. Since no evidence-based guidelines support the challenge for anesthesiologists various practical recommendations exist in clinical practice for rapid sequence induction and intubation (RSI). The aim of this systematic review is, to summarize the evidence and recommend a decision making process. MATERIAL AND METHODS: Multilevel RAND-delphi-method (RAND: Research and Development) combined with systematic literature research, individual assessment and evaluation, consensus conferences and final common sequence. RESULTS AND DISCUSSION: The consideration of all practical, clinical procedures in patients at risk for aspiration represents an effective prevention of pulmonary aspiration during the induction of anesthesia. These include the optimal drug pre-treatment with antacids (e. g. sodium citrate) for highly aspiration-endangered and proton pump inhibitors or H2 blockers in other patients the evening before. Each patient should be examined and explained prior to RSI according to the recommendations of the National German Society of Anesthesiology for preoperative evaluation. A RSI should be performed in patients with no 2h liquid and no 6h food fasting or acute vomiting, sub-ileus or ileus, or no protective reflexes or a gastrointestinal passenger disorder. In addition, RSI should be performed in pregnant women after the 3rd trimester and during birth. The expertise and competence of the physician before and during rapid sequence induction and intubation about the respective task distribution minimizes the risk of aspiration, as does the adequate equipment, as well as an optimized upper body elevation of the patient. Consistent pre-oxygenation with an FIO2 of 1.0 (FetO2-concentration > 0.9) and an oxygen flow > 10 l/min using a completely sealing respiratory mask with capnography should take 3-5 minutes. Fast enough deep anesthesia and muscle relaxation to avoid coughing and choking can be achieved by a combination of opioid, hypnotic and muscle relaxation. In addition, an opioid of choice, propofol, thiopental, etomidate and ketamine can be used as hypnotic and rocuronium with the availability of sugammadex should be used as muscle relaxant. If there are no contraindications, succinylcholine can also be used as a muscle relaxant. In case of an unexpected difficult airway, a 2nd generation extraglottic airway device should be used. During regurgitation or aspiration, intensive medical monitoring and fiber-optic bronchoscopy should be performed, depending on the degree of severity and an X­ray thorax image or a CT scan should be performed if symptoms arise. Three factors reduce the risk of aspiration: expertise, support from an experienced anesthesiologist and close monitoring of an inexperienced anesthesiologist.

Oesophageal Doppler guided goal-directed haemodynamic therapy in thoracic surgery - a single centre randomized parallel-arm trial.

BACKGROUND: Postoperative pulmonary and renal complications are frequent in patients undergoing lung surgery. Hyper- and hypovolaemia may contribute to these complications. We hypothesized that goal-directed haemodynamic management based on oesophageal Doppler monitoring would reduce postoperative pulmonary complications in a randomized clinical parallel-arm trial. METHODS: One hundred patients scheduled for thoracic surgery were randomly assigned to either standard haemodynamic management (control group) or goal-directed therapy (GDT group) guided by an oesophageal Doppler monitoring-based algorithm. The primary endpoint was postoperative pulmonary complications, including spirometry. Secondary endpoints included haemodynamic variables, renal, cardiac, and neurological complications, and length of hospital stay. The investigator assessing outcomes was blinded to group assignment. RESULTS: Forty-eight subjects of each group were analysed. Compared to the control group, fewer subjects in the GDT group developed postoperative pulmonary complications (6 vs. 15 patients; P = 0.047), while spirometry did not differ between groups. Compared to the control group, patients of the GDT group showed higher cardiac index (2.9 vs. 2.1 [l min - 1 m - 2 ]; P < 0.001) and stroke volume index (43 vs. 34 [ml m 2 ]; P < 0.001) during surgery. Renal, cardiac and neurological complications did not differ between groups. Length of hospital stay was shorter in the GDT compared to the control group (9 vs. 11 days; P = 0.005). CONCLUSIONS: Compared to standard haemodynamic management, oesophageal Doppler monitor-guided GDT was associated with fewer postoperative pulmonary complications and a shorter hospital stay. CLINICAL TRIAL REGISTRATION.: The study was registered in the German Clinical Trials Register (DRKS 00006961). https://drks-neu.uniklinik-freiburg.de/drks_web/.

[A Germany-wide survey on anaesthesia in thoracic surgery]. / Deutschlandweite Umfrage zur Thoraxanästhesie.

BACKGROUND/OBJECTIVE: This study's objective was to evaluate current thoracic anaesthesia practice in Germany and to quantify potential differences depending on the hospital's level of care. MATERIALS AND METHODS: A four-part online survey containing 28 questions was mailed to all anaesthesiology department chairs (n = 777) registered with the German Society of Anaesthesiology and Intensive Care Medicine. RESULTS: The general response rate was 31.5 % (n = 245). High monthly volumes (>50 operations/month) of intrathoracic procedures, performed by specialized thoracic surgeons are mostly limited to hospitals of maximum care, university hospitals, and specialized thoracic clinics. In hospitals with a lower level of care, intrathoracic operations occur less frequently (1-5/month) and are commonly performed by general (69.3 %) rather than thoracic surgeons (15.4 %). Video-assisted thoracic surgeries are the most invasive intrathoracic procedures for most hospitals with a low level of care (61.5 %). Extended resections and pneumonectomies occur mainly in hospitals of maximum care and university hospitals. Thoracic anaesthesia is primarily performed by consultants or senior physicians (59.9 %). The double lumen tube (91.4 %) is the preferred method to enable one-lung ventilation (bronchial blockers: 2.7 %; missing answer: 5.9 %). A bronchoscopic confirmation of the correct placement of a double lumen tube is considered mandatory by 87.7 % of the respondents. Bronchial blockers are available in 64.7 % of all thoracic anaesthesia departments. While CPAP-valves for the deflated lung are commonly used (74.9 %), jet-ventilators are rarely accessible, especially in hospitals with a lower level of care (15.4 %). Although general algorithms for a difficult airway are widely available (87.7 %), specific recommendations for a difficult airway in thoracic anaesthesia are uncommon (4.8 %). Laryngeal mask airways (90.9 %) and videolaryngoscopy (88.8 %) are the primary adjuncts in store for a difficult airway. While hospitals with a lower level of care admitted patients routinely (92.3 %) to an intensive care unit after thoracic surgery, larger clinics used the postanaesthesia recovery room (12.5 %) and intermediate care units (14.6 %) more frequently for further surveillance. Thoracic epidural catheters (85.6 %) are predominantly chosen for peri- and postoperative analgesia, in contrast to paravertebral blockade (single shot: 8.6 %; catheter: 8.0 %) (multiple answers possible). Ultrasound is generally accessible (84.5 %) and mostly employed for the placement of central venous (81.3 %) and arterial (43.9 %) lines as well as a diagnostic tool for pulmonary pathology (62.0 %). CONCLUSION: The study reveals considerable differences in the anaesthetic practice in thoracic surgery. These focus mostly on the postoperative surveillance, the availability of bronchial blockers, and the use of regional anaesthetic techniques. Furthermore, it is evident that specific algorithms are needed for the difficult airway in thoracic anaesthesia. A recommendation for the high-tech work environment of thoracic anaesthesia could enhance the structural quality and optimize patient outcomes. Independent of a hospital's level of care, uniform requirements could help establish national quality standards in thoracic anaesthesia.

Double-lumen tubes and auto-PEEP during one-lung ventilation.

BACKGROUND: Double-lumen tubes (DLT) are routinely used to enable one-lung-ventilation (OLV) during thoracic anaesthesia. The flow-dependent resistance of the DLT's bronchial limb may be high as a result of its narrow inner diameter and length, and thus potentially contribute to an unintended increase in positive end-expiratory pressure (auto-PEEP). We therefore studied the impact of adult sized DLTs on the dynamic auto-PEEP during OLV. METHODS: In this prospective clinical study, dynamic auto-PEEP was determined in 72 patients undergoing thoracic surgery, with right- and left-sided DLTs of various sizes. During OLV, air trapping was provoked by increasing inspiration to expiration ratio from 1:2 to 2:1 (five steps). Based on measured flow rate, airway pressure (Paw) and bronchial pressure (Pbronch), the pressure gradient across the DLT (ΔPDLT) and the total auto-PEEP in the respiratory system (i.e. the lungs, the DLT and the ventilator circuit) were determined. Subsequently the DLT's share in total auto-PEEP was calculated. RESULTS: ΔPDLT was 2.3 (0.7) cm H2O over the entire breathing cycle. At the shortest expiratory time the mean total auto-PEEP was 2.9 (1.5) cm H2O (range 0-5.9 cm H2O). The DLT caused 27 to 31% of the total auto-PEEP. Size and side of the DLT's bronchial limb did not impact auto-PEEP significantly. CONCLUSIONS: Although the DLT contributes to the overall auto-PEEP, its contribution is small and independent of size and side of the DLT's bronchial limb. The choice of DLT does not influence the risk of auto-PEEP during OLV to a clinically relevant extent. CLINICAL TRIAL REGISTRATION: DRKS00005648.

[Thoracic epidural catheter: reasonable or over-instrumentation?]. / Thorakaler Periduralkatheter: Sinnvoll oder Überinstrumentierung?

The efficient and persisting treatment of the pain accompanying thoracic surgery is fundamental and beneficial for patients, since severe postoperative pulmonary complications and the incidence of chronic pain will be reduced. In this review the role of thoracic epidural analgesia in preventing and treating pain after thoracic surgery will be discussed critically and alternative strategies presented.

Combined paravertebral and intrathecal vs thoracic epidural analgesia for post-thoracotomy pain relief.

BACKGROUND: Although thoracic epidural analgesia (TEA) is considered the gold standard for post-thoracotomy pain relief, thoracic paravertebral block (PVB) and intrathecal opioid (ITO) administration have also been shown to be efficacious. We hypothesized that the combination of PVB and ITO provides analgesia comparable with that of TEA. METHODS: After local ethics committee approval, 84 consecutive patients undergoing open thoracic procedures were randomized to the TEA (ropivacaine 0.2%+sufentanil) or the PVB (ropivacaine 0.5%)+ITO (sufentanil+morphine) group. The primary endpoints were pain intensities at rest and during coughing/movement at 1, 2, 4, 8, 12, 24, 48, and 72 h after operation assessed by visual analogue scale (VAS) score. Data were analysed by multivariate analysis (anova; P<0.05). RESULTS: Patient and surgical characteristics were comparable between the groups. The mean and maximal VAS scores were lower in the TEA (n=43) than in the PVB+ITO group (n=37) at several time points at rest (P<0.026) and during coughing/movement (P<0.021). However, in the PVB+ITO group, the mean VAS scores never exceeded 1.9 and 3.5 at rest and during coughing/movement, respectively; and the maximal differences between the groups (TEA vs PVB+ITO) in the maximal VAS scores were only 1.2 (3.4 vs 4.6) at rest, and 1.3 (4.4 vs 5.7) during coughing/movement. CONCLUSIONS: Although VAS scores were statistically lower in the TEA compared with the PVB+ITO group at some observation points, the differences were small and of questionable clinical relevance. Thus, combined PVB and ITO can be considered a satisfactory alternative to TEA for post-thoracotomy pain relief. ClinicalTrials.gov number. NCT00493909.

[High risk pulmonary embolism. Case report of a successful embolectomy]. / Hochrisikolungenembolie. Fallbeschreibung einer erfolgreichen Embolektomie.

High risk pulmonary embolism commonly presents with a variety of symptoms and is an acute life-threatening event. In patients showing unclear acute circulatory distress, pulmonary embolism should be quickly ruled out by computed tomography or echocardiography. The diagnostic steps and surgical treatment of pulmonary embolism in a 25-year-old female patient suffering from acute circulatory insufficiency resulting in cardiac arrest within 11 min after emergency hospital admission are reported. Due to the reasonable suspicion of acute right heart decompensation, systemic perfusion was re-established by cardiopulmonary bypass after cardiopulmonary resuscitation for 41 min. Sternotomy and surgical embolectomy were performed. The patient was successfully extubated the following day and despite the long resuscitation time the outcome was excellent without any neurological deficit. Recent publications addressing the advantages of primary embolectomy versus intravenous thrombolysis in acute circulatory distress caused by pulmonary embolism are discussed. Primary surgical treatment including cardiopulmonary bypass for right ventricular relief and re-establishing of systemic perfusion is recommended for patients with pulmonary embolism undergoing cardiopulmonary resuscitation.

Protective effects of inhaled carbon monoxide in pig lungs during cardiopulmonary bypass are mediated via an induction of the heat shock response.

BACKGROUND: Cardiopulmonary bypass (CPB) may cause acute lung injury leading to increased morbidity and mortality after cardiac surgery. Preconditioning by inhaled carbon monoxide reduces pulmonary inflammation during CPB. We hypothesized that inhaled carbon monoxide mediates its anti-inflammatory and cytoprotective effects during CPB via induction of pulmonary heat shock proteins (Hsps). METHODS: Pigs were randomized either to a control group, to standard CPB, to carbon monoxide+CPB, or to quercetin (a flavonoid and unspecific inhibitor of the heat shock response)+control, to quercetin+CPB, and to quercetin+carbon monoxide+CPB. In the carbon monoxide groups, lungs were ventilated with 250 ppm carbon monoxide in addition to standard ventilation before CPB. At various time points, lung biopsies were obtained and pulmonary Hsp and cytokine concentrations determined. RESULTS: Haemodynamic parameters were largely unaffected by CPB, carbon monoxide inhalation, or administration of quercetin. Compared with standard CPB, carbon monoxide inhalation significantly increased the pulmonary expression of the Hsps 70 [27 (SD 3) vs 69 (10) ng ml(-1) at 120 min post-CPB, P<0.05] and 90 [0.3 (0.03) vs 0.52 (0.05) after 120 min CPB, P<0.05], induced the DNA binding of heat shock factor-1, reduced interleukin-6 protein expression [936 (75) vs 320 (138) at 120 min post-CPB, P<0.001], and decreased CPB-associated lung injury (assessed by lung biopsy). These carbon monoxide-mediated effects were inhibited by quercetin. CONCLUSIONS: As quercetin, a Hsp inhibitor, reversed carbon monoxide-mediated pulmonary effects, we conclude that the anti-inflammatory and protective effects of preconditioning by inhaled carbon monoxide during CPB in pigs are mediated by an activation of the heat shock response.

[Epidural analgesia in thoracic surgery--optimising postoperative rehabilitation]. / Einsatz der epiduralen Analgesie in der konventionellen Thoraxchirurgie--Optimierung der postoperativen Rehabilitation.

INTRODUCTION: A multimodal perioperative therapy strategy (fast-track) decreases the morbidity of general thoracic interventions and increases postoperative reconvalescence after lung resections. Thoracic surgery is associated with relevant pain and sufficient pain relief is essential for postoperative recovery. Epidural analgesia leads to adequate pain control with only minor side effects and complications and can therefore be a reasonable supplementation in a modern fast-track setting. The purpose of this study was to evaluate the benefits and risks of an epidural catheter placed prior to surgery and to analyse the postoperative recovery of patients undergoing thoracic surgery. METHODS: 277 patients undergoing pulmonary resection through an anterolateral thoracotomy were included in our study. Epidural analgesia was carried out through placement of an epidural catheter equipped with Naropine-Sufenta perfusor prior to surgery. Perioperative clinical parameters as well as postoperative management were evaluated. Pain intensity was documented using the visual analogue scale (VAS). Side effects and complications were summarised in five grades of severity (1-5). Insufficient pain relief was recognised when a VAS > 4 was registered. RESULTS: Median patient age was 59 years, the male / female relation was precisely 2 : 1, on average epidural analgesia was carried out for 4.9 days. Severe complications (grade 4 or 5) were not found. In 37 % of the cases, minor complications and side effects were found, in 1 % clinical relevant complications led to further diagnostic measures. For sufficient pain relief, 10 % of the studied population needed additional treatment with systemic opioids. CONCLUSION: We have shown that epidural analgesia in patients undergoing thoracotomy leads to sufficient pain control with only minor disadvantages and complications. These are easily mastered without expensive diagnostic or therapeutic interventions. Therefore, epidural analgesia is a safe and helpful tool for increased postoperative recovery within a modern fast-track setting.

Electrical impedance tomography to confirm correct placement of double-lumen tube: a feasibility study.

BACKGROUND: Double-lumen tubes (DLTs) are frequently used to establish one-lung ventilation (OLV). Their correct placement is crucial. We hypothesized that electrical impedance tomography (EIT) reliably displays distribution of ventilation between left and right lung and may thus be used to verify correct DLT placement online. METHODS: Regional ventilation was studied by EIT in 40 patients requiring insertion of left-sided DLTs for OLV during thoracic surgery. EIT was recorded during two-lung ventilation before induction of anaesthesia and after DLT placement, and during OLV in the supine and subsequently in the lateral position. EIT measurements were made before and after verification of correct DLT placement by fibreoptic bronchoscopy (FOB). RESULTS: EIT accurately displayed distribution of ventilation between left and right lung online. All cases (n=5) of initially misplaced DLTs in the contralateral right main bronchus were detected by EIT. However, EIT did not allow prediction of FOB-detected endobronchial cuff misplacement requiring DLT repositioning. Furthermore, after DLT repositioning, distribution of ventilation, as assessed by EIT, did not change significantly (all P>0.5). CONCLUSIONS: This study demonstrates that EIT enables accurate display of left and right lung ventilation and, thus, non-invasive online recognition of misplacement of left-sided DLTs in the contralateral main bronchus. However, as distribution of ventilation did not correlate with endobronchial cuff placement, EIT cannot replace FOB in the routine control of DLT position.

Comparison of cellular functionality of human mesenchymal stromal cells and PBMC.

BACKGROUND: Human mesenchymal stromal cells (MSC) and PBMC play significant roles in repair processes following inflammation. Mechanisms of recruitment are still under investigation. METHODS AND RESULTS: MIP-1alpha induced the chemotactic migration of MSC but not of PBMC. Correlating with this, 7.7% of MSC expressed the chemokine receptor CCR-1, as shown by FACS analysis. In contrast, PBMC did not express CCR-1 or CCR-2 but did express CXCR-4 (81.9%) and CCR-7 (42.2%). Setum induced the chemotaxis of both cell types, and zymosan activation increased the migration of PBMC but not of MSC. Corresponding with this, C5a induced the migration of PBMC but not of MSC. Dose-dependent and -specific adhesion to fibronectin, fibrinogen, collagen type I and collagen type II could be demonstrated for MSC; in contrast, PBMC did not adhere to any of the investigated proteins. Real-time PCR of receptor expression revealed a 12.2-fold higher expression of alphav in MSC compared with PBMC. Incubation of MSC with tumor necrosis factor-alpha (TNFalpha) induced NFkappaB activation and increased the chemotactic response to serum and adhesion to fibronedtin. DISCUSSION: Chemotaxis and adhesion are crucial and differing cell fundtons of MSC and PBMC.