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.

[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/.

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.

[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.

[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.

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.