Quantification of exhaled propofol is not feasible during single-lung ventilation using double-lumen tubes: A multicenter prospective observational trial.

BACKGROUND: Volatile propofol can be measured in exhaled air and correlates to plasma concentrations with a time delay. However, the effect of single-lung ventilation on exhaled propofol is unclear. Therefore, our goal was to evaluate exhaled propofol concentrations during single-lung compared to double-lung ventilation using double-lumen tubes. METHODS: In a first step, we quantified adhesion of volatile propofol to the inner surface of double-lumen tubes during double- and single-lumen ventilation in vitro. In a second step, we enrolled 30 patients scheduled for lung surgery in two study centers. Anesthesia was provided with propofol and remifentanil. We utilized left-sided double-lumen tubes to separately ventilate each lung. Exhaled propofol concentrations were measured at 1-min intervals and plasma for propofol analyses was sampled every 20 min. To eliminate the influence of dosing on volatile propofol concentration, exhalation rate was normalized to plasma concentration. RESULTS: In-vitro ventilation of double-lumen tubes resulted in increasing propofol concentrations at the distal end of the tube over time. In vitro clamping the bronchial lumen led to an even more pronounced increase (Δ AUC +62%) in propofol gas concentration over time. Normalized propofol exhalation during lung surgery was 31% higher during single-lung compared to double-lung ventilation. CONCLUSION: During single-lung ventilation, propofol concentration in exhaled air, in contrast to our expectations, increased by approximately one third. However, this observation might not be affected by change in perfusion-ventilation during single-lung ventilation but rather arises from reduced propofol absorption on the inner surface area of the double-lumen tube. Thus, it is only possible to utilize exhaled propofol concentration to a limited extent during single-lung ventilation. REGISTRATION OF CLINICAL TRIAL: DRKS-ID DRKS00014788 (www.drks.de).

Comparison of left double lumen tube and y-shaped and double-ended bronchial blocker for one lung ventilation in thoracic surgery-a randomised controlled clinical trial.

BACKGROUND: Double lumen tube (DLT) intubation is the most commonly used technique for one lung ventilation. Bronchial blockers (BB) are an alternative, especially for difficult airways. The EZ-bronchial blocker (EZB) is an innovative y-shaped and double-ended device of the BB family. METHODS: A randomised, controlled trial was conducted in 80 patients undergoing elective thoracic surgery using DLT or EZB for one lung ventilation (German Clinical Trial Register DRKS00014816). The objective of the study was to compare the clinical performance of EZB with DLT. Primary endpoint was total time to obtain successful one lung ventilation. Secondary endpoints were time subsections, quality of lung collapse, difficulty of intubation, any complications during the procedure, incidence of objective trauma of the oropharynx and supraglottic space and intubation-related subjective symptoms. RESULTS: 74 patients were included, DLT group (n = 38), EZB group (n = 36). Median total time to obtain one lung ventilation [IQR] in the DLT group was 234 s [207 to 294] versus 298 s [243 to 369] in the EZB group (P = 0.007). Median total time was relevantly influenced by different preparation times. Quality of lung collapse was equal in both groups, DLT group 89.5% were excellent vs. 83.3% in the EZB group (P = 0.444). Inadequate lung collapse in five patients of the EZB group resulted in unsuccessful repositioning attempts and secondary DLT placement. Endoscopic examinations revealed significantly more carina trauma (P = 0.047) and subglottic haemorrhage (P = 0.047) in the DLT group. Postoperative subjective symptoms (sore throat, hoarseness) were more common in the DLT group, as were speech problems. CONCLUSIONS: Using EZB prima facie results in prolonged time to obtain one lung ventilation with equal quality of lung collapse for the thoracic surgeon. If preparation times are omitted in the analysis, the time difference is statistically and clinically not relevant. Our data showed only little evidence for reducing objective airway trauma as well as subjective complaints. In summary both procedures were comparable in terms of times and clinical applicability. Therefore decisions for DLT or EZB should depend more on individual experience, in-house equipment and the individual patient, than on any times that are neither clinically significant nor relevant. TRIAL REGISTRATION: German Clinical Trial Register DRKS00014816 , prospectively registered on 07.06.2018.

Videolaryngoscopy versus direct laryngoscopy for double-lumen endotracheal tube intubation in thoracic surgery - a randomised controlled clinical trial.

BACKGROUND: Double-lumen tube (DLT) intubation is necessary for thoracic surgery and other operations with the need for lung separation. However, DLT insertion is complex and might result in airway trauma. A new videolaryngoscopy (GVL) with a thin blade might improve the intubation time and reduce complexity as well as iatrogenic airway complications compared to conventional direct laryngoscopy (DL) for DLT intubation. METHODS: A randomised, controlled trial was conducted in 70 patients undergoing elective thoracic surgery using DLT for lung separation. Primary endpoint was time to successful intubation. The secondary endpoints of this study were number of intubation attempts, the assessment of difficulty, any complications during DLT intubation and the incidence of objective trauma of the oropharynx and supraglottic space and intubation-related subjective symptoms. RESULTS: 65 patients were included (DL group [n  =  31], GVL group [n  =  34]). Median intubation time (25th-75th percentiles) in GVL group was 93 s (63-160) versus 74 (58-94) in DL group [p = 0.044]. GVL resulted in significantly improved visualisation of the larynx (Cormack and Lehane grade of 1 in GVL group was 97% vs. 74% in DL Group [p = 0.008]). Endoscopic examinations revealed significant differences in GVL group compared to DL group showing less red-blooded vocal cord [p = 0.004], vocal cord haematoma [p = 0.022] and vocal cord haemorrhage [p = 0.002]. No significant differences regarding the postoperative subjective symptoms of airway were found. CONCLUSIONS: Videolaryngoscopy using the GlideScope®-Titanium shortly prolongs DLT intubation duration compared to direct laryngoscopy but improves the view. Objective intubation trauma but not subjective complaints are reduced. TRIAL REGISTRATION: German Clinical Trial Register DRKS00020978, retrospectively registered on 09. March 2020.

Programmed intermittent epidural bolus versus continuous epidural infusion for postoperative analgesia after major abdominal and gynecological cancer surgery: a randomized, triple-blinded clinical trial.

BACKGROUND: Continuous epidural infusion (CEI) is the standard application setting for epidural infusion. A new mode, the programmed intermittent epidural bolus (PIEB) technique, showed reduced local anesthetic (LA) consumption and improved analgesia in obstetric analgesia. Goal of this trial was to evaluate the effects of PIEB versus CEI [combined with patient-controlled bolus (PCEA)] on LA consumption and pain scorings in major abdominal cancer surgery. METHODS: Following ethical approval, patients scheduled for major abdominal cancer surgery under general anesthesia in combination with epidural analgesia were randomized to receive either a PIEB mode of 6 mL/h or a CEI mode set at 6 mL/h of ropivacaine 0.2%, both combined with a PCEA mode set at a 4 mL bolus. LA consumptions and pain scorings were documented until the second postoperative evening. RESULTS: Eighty-four datasets were analyzed (CEI: n = 40, PIEB: n = 44). Regarding the primary endpoint, cumulative LA PCEA bolus volumes until day 2 differed significantly between the groups [PIEB 10 mL (2-28 mL) versus CEI, 28 mL (12-64 mL), median (25th-75th percentiles), p = 0.002]. Overall, LA consumption volumes were significantly lower in the PIEB group versus in the CEI group [PIEB: 329 mL (291-341 mL) vs. CEI: 350 mL (327-381 mL), p = 0.003]. Pain scores were comparable at each time point. CONCLUSIONS: This trial demonstrates reduced needs for PCEA bolus in the PIEB group. There were no clinically relevant benefits regarding morphine consumption, pain scorings, or other secondary outcome parameters. TRIAL REGISTRATION: This study has been registered retrospectively in the ClinicalTrials.gov registry ( NCT03378804 ), date of registration: December, 20th 2017.

Ultrasound-guided single injection versus continuous sciatic nerve blockade on pain management and mobilisation after total knee arthroplasty (CoSinUS trial): A randomised, triple-blinded controlled trial.

BACKGROUND: Combining continuous femoral nerve blockade with single injection sciatic nerve blockade is standard peripheral nerve block practice for total knee arthroplasty (TKA) during the first 24 postoperative hours. OBJECTIVES: To assess the analgesic benefits and mobilisation capability of continuous sciatic blockade in conjunction with continuous femoral nerve blockade for 72 h after arthroplasty. DESIGN: Randomised, triple-blinded controlled trial. SETTING: Single-Centre, German University Hospital. PATIENTS: In total, 50 patients receiving continuous femoral nerve blockade (5 ml h ropivacaine 0.2%) for TKA under general anaesthesia. INTERVENTIONS: Patients were randomised to receive a sciatic nerve catheter with an initial dose of 10 ml ropivacaine 0.2% followed by either continuous double-blinded application of 5 ml h ropivacaine 0.2% (CO) or 5 ml h saline infusion (SIN). MAIN OUTCOME: Measures primary endpoint: cumulative morphine consumption until 48 h postoperatively. Further endpoints included morphine consumption, pain scores, mobilisation, dynamometry until postoperative day 3. RESULTS: Median [25th to 75th percentiles] cumulative morphine consumption at postoperative day 2 differed significantly between groups (CO 15 mg [11 to 25] versus SIN, 43 mg [27 to 67.5, P < 0.0001) in the 48 patients in the final analysis. Overall pain scores were comparable at rest and during stress at each time point. However, significantly higher pain scores of the popliteal fossa were observed in the SIN group. Mobilisation was comparable between groups. CONCLUSION: This trial demonstrates the superior analgesic effects of continuous sciatic nerve block compared with a single injection in combination with continuous femoral blockade during the first 72 h after TKA. However, mobilisation capability was impaired in both groups. Improved pain control from two catheters needs to be balanced against the potential risks of impaired mobilisation and patient falls. TRIAL REGISTRATION: DRKS - German clinical trials register (no: DRKS00010152).

Tranexamic Acid Prophylaxis in Hip and Knee Joint Replacement.

BACKGROUND: The antifibrinolytic agent tranexamic acid (TXA) is widely used for the prevention and treatment of hyperfibrinolytic states, such as in severe polytrauma. It can also be used for the systemic prevention of hemorrhage in elective orthopedic procedures. In this review, we assess the efficacy and risks of the prophylactic administration of tranexamic acid before major endoprosthetic surgery of the hip and knee. METHODS: This review is based on pertinent articles retrieved by a selective literature search in the PubMed and Cochrane Library databases. RESULTS: Endoprosthetic surgery of the hip and knee is often associated with perioperative blood losses exceeding 500 mL. The prophylactic administration of tranexamic acid immediately before such procedures has been shown in randomized, controlled trials to lessen the quantity of intra- and postoperative bleeding and to reduce the likelihood of blood transfusion (number needed to treat [NNT] 3.7-5.7 for knee replacement and 4.1-8.2 for hip replacement). The rate of thromboembolic events did not differ significantly from the rate in the placebo groups. No reliable data are available on the frequency of epileptic seizures as a complication of TXA use in knee and hip endoprosthetic surgery. On the basis of data from other types of surgery, one may reasonably conclude that the doses of TXA used for knee and hip endoprosthetic procedures are unlikely to cause this problem. CONCLUSION: The prophylactic intravenous administration of tranexamic acid lessens the amount of bleeding in endoprosthetic knee and hip procedures and reduces the likelihood of blood transfusion. According to the current state of the evidence, complications are rare. Nonetheless, consideration of the risks and benefits implies that tranexamic acid should not be given for this purpose to patients who have recently had urogenital bleeding, pulmonary embolism, or a myocardial infarction, who have recently undergone percutaneous transluminal coronary angioplasty or stenting, or who are known to have epilepsy.

Dantrolene versus amiodarone for cardiopulmonary resuscitation: a randomized, double-blinded experimental study.

Dantrolene was introduced for treatment of malignant hyperthermia. It also has antiarrhythmic properties and may thus be an alternative to amiodarone for the treatment of ventricular fibrillation (VF). Aim of this study was to compare the return of spontaneous circulation (ROSC) with dantrolene and amiodarone in a pig model of cardiac arrest. VF was induced in anesthetized pigs. After 8 min of untreated VF, chest compressions and ventilation were started and one of the drugs (amiodarone 5 mg kg-1, dantrolene 2.5 mg kg-1 or saline) was applied. After 4 min of initial CPR, defibrillation was attempted. ROSC rates, hemodynamics and cerebral perfusion measurements were measured. Initial ROSC rates were 7 of 14 animals in the dantrolene group vs. 5 of 14 for amiodarone, and 3 of 10 for saline). ROSC persisted for the 120 min follow-up in 6 animals in the dantrolene group, 4 after amiodarone and 2 in the saline group (n.s.). Hemodynamics were comparable in both dantrolene group amiodarone group after obtaining ROSC. Dantrolene and amiodarone had similar outcomes in our model of prolonged cardiac arrest, However, hemodynamic stability was not significantly improved using dantrolene. Dantrolene might be an alternative drug for resuscitation and should be further investigated.

Continuous adductor canal block versus continuous femoral nerve block after total knee arthroplasty for mobilisation capability and pain treatment: a randomised and blinded clinical trial.

INTRODUCTION: Continuous femoral nerve blocks for total knee arthroplasty can cause motor weakness of the quadriceps muscle and thus prevent early mobilisation. Perioperative falls may result as an iatrogenic complication. In this randomised and blinded trial, we tested the hypothesis that a continuous adductor canal block is superior to continuous femoral nerve block regarding mobilisation ('timed up-and-go' test and other tests) after total knee arthroplasty under general anaesthesia. METHODS: In our study, we included patients scheduled for unilateral knee arthroplasty under general anaesthesia into a blinded and randomised trial. Patients were allocated to a continuous adductor canal block (CACB) or a continuous femoral nerve block (CFNB) for three postoperative days (POD 1-3); with a bolus of 15 ml ropivacaine 0.375%, followed by continuous infusion of ropivacaine 0.2% and patient-controlled bolus administration. Both groups received an additional continuous sciatic nerve block as well as a multimodal systemic analgesic treatment. The primary outcome parameter was mobilisation capability, assessed by 'timed up-and-go' (TUG) test. Analgesic quality, need for opioid rescue and local anaesthetic consumption were also assessed. RESULTS: Forty-two patients were included and analysed (21 patients per group). No significant difference was noted in respect to mobilisation at POD 3 (TUG [s]: CACB 45, CFNB 51). It is worth saying that pain scores (numeric rating scale, NRS) were similar in both groups at POD 3 {rest [median (interquartile range)]: CACB 0 (0-3), CFNB 1 (0-3); stress: CACB 4 (2-5), CFNB 3 (2-4)}. CONCLUSIONS: Concerning the mobilisation capability, we did not actually observe a superior effect of CACB compared with CFNB technique in our patients following total knee arthroplasty. Moreover, no difference was observed concerning analgesia quality.