Bilateral erector spinae plane block with single injection

Correction to: Economic and operational impact of an improved pathway using rapid molecular diagnostic testing for patients with influenza-like illness in a German emergency department The article Economic and operational impact of an improved pathway using rapid molecular diagnostic testing for patients with influenza-like illness in a German emergency department, written by Matthias Brachmann, Katja Kikull, Clemens Kill and Susanne Betz, was originally published electronically on the publisher’s internet portal (currently SpringerLink) on 04 January 2019 without open access.

Administration of anesthetic drugs according to pharmacological principles: are we heading in the right direction?

Predicting vital sign deterioration with artificial intelligence or machine learning

Using the capnogram to assess pulmonary perfusion during a lobectomy: case studies Abstract Capnography is an effective and non-invasive method for monitoring patients during general anesthesia and can reflect the changes in both the respiratory function as well as the circulatory function. In this paper, we present four cases of lobectomy in which we observed a “chair-like” waveform on performing capnography after the surgery. In all the cases, the appearance of this “chair-like” waveform led to the suspicion of a blockage in the pulmonary artery perfusion, which was then confirmed to be an obstruction in the pulmonary artery on further investigation. This suggests that during lobectomy, capnography can help confirm that the pulmonary circulation is unobstructed. We believe that it is very important to observe the changes of end-tidal carbon dioxide pressure and capnogram during one-lung ventilation, particularly in cases of pulmonary artery anastomosis.

Oxygen reserve index (ORi™) contributes to prediction of hypoxemia and patient safety during tracheal stent insertion using rigid bronchoscopy: a case report Abstract The oxygen reserve index (ORi™) is a new noninvasive and continuous variable, which represents a moderate hyperoxygenation status, with a unitless scale between 0.00 and 1.00. When percutaneous oxygen saturation (SpO2) exceeds 100%, arterial blood oxygen partial pressure cannot be evaluated without performing arterial blood gas analysis. Because of significant air leakage during rigid bronchoscopy, it is difficult to monitor respiration using capnography, which does not measure end-tidal carbon dioxide (ETCO2) accurately. A 66-year-old man (175 cm, 76.8 kg) with a chief complaint of difficulty in breathing was diagnosed with a thyroid tumor. Computed tomography revealed tracheal stenosis due to direct invasion of the thyroid tumor; therefore, tracheal stenting was planned immediately. After supplying 6 L/min oxygen with a face mask and administering 180 mg of propofol intravenously, the supraglottic airway was intubated. General anesthesia (total intravenous anesthesia) through continuous administration of 6–10 mg/kg/h of propofol and intermittent administration of 50 µg of fentanyl (total 200 µg) preserved spontaneous breathing. During tracheal stent insertion, disconnection between the oxygen supply system and rigid bronchoscopy, and tracheal stent expansion, the ORi tended to decrease before SpO2 decreased. Thus, measuring ORi could prevent hypoxemia during tracheal stent insertion using rigid bronchoscopy.

Evaluation and application of a method for estimating nasal end-tidal O 2 fraction while administering supplemental O 2 Abstract This paper describes a method for estimating the oxygen enhanced end-tidal fraction of oxygen (FetOe), the end-tidal fraction of oxygen (FetO2) that is raised by administering supplemental oxygen. The paper has two purposes: the first is to evaluate the method’s accuracy on the bench and in volunteers; the second purpose is to demonstrate how to apply the method to compare two techniques of oxygen administration. The method estimates FetOe by analyzing expired oxygen as oxygen washes out of the lung. The method for estimating FetOe was first validated using a bench simulation in which tracheal oxygen was measured directly. Then it was evaluated in 30 healthy volunteers and compared to the bench simulation. Bland–Altman analysis compared calculated and observed FetOe/FetO2 measurements. After the method was evaluated, it was implemented to compare the FetOe obtained when administering oxygen using two different techniques (pulsed and continuous flow). A total of eighteen breath washout conditions were evaluated on the bench. FetOe estimates and tracheal FetO2 had a mean difference of − 0.016 FO2 with 95% limits of agreement from − 0.048 to 0.016 FO2. Thirteen breath washouts per volunteer were analyzed. Extrapolated and observed FetO2 had a mean difference of − 0.001 FO2 with 95% limits of agreement from − 0.006 to 0.004 FO2. Pulsed flow oxygen (PFO) achieved the same FetOe values as continuous flow oxygen (CFO) using 32.1% ± 2.27% (mean ± SD) of the CFO rate. This paper has demonstrated that the method estimates FetO2 enhanced by administering supplemental oxygen with clinically insignificant differences. This paper has also shown that PFO can obtain FetO2 similar to CFO using approximately one-third of the oxygen volume. After evaluating this method, we conclude that the method provides useful estimates of nasal FetO2 enhanced by supplemental oxygen administration.

Near-real-time pulmonary shunt and dead space measurement with micropore membrane inlet mass spectrometry in pigs with induced pulmonary embolism or acute lung failure Abstract The multiple inert gas elimination technique (MIGET) using gas chromatography (GC) is an established but time-consuming method of determining ventilation/perfusion (VA/Q) distributions. MIGET—when performed using Micropore Membrane Inlet Mass Spectrometry (MMIMS)—has been proven to correlate well with GC-MIGET and reduces analysis time substantially. We aimed at comparing shunt fractions and dead space derived from MMIMS–MIGET with Riley shunt and Bohr dead space, respectively. Thirty anesthetized pigs were randomly assigned to lavage or pulmonary embolism groups. Inert gas infusion (saline mixture of SF6, krypton, desflurane, enflurane, diethyl ether, acetone) was maintained, and after induction of lung damage, blood and breath samples were taken at 15-min intervals over 4 h. The samples were injected into the MMIMS, and resultant retention and excretion data were translated to VA/Q distributions. We compared MMIMS-derived shunt (MM-S) to Riley shunt, and MMIMS-derived dead space (MM-VD) to Bohr dead space in 349 data pairs. MM-S was on average lower than Riley shunt (− 0.05 ± 0.10), with lower and upper limits of agreement of − 0.15 and 0.04, respectively. MM-VD was on average lower than Bohr dead space (− 0.09 ± 0.14), with lower and upper limits of agreement of − 0.24 and 0.05. MM-S and MM-VD correlated and agreed well with Riley shunt and with Bohr dead space. MM-S increased significantly after lung injury only in the lavage group, whereas MM-VD increased significantly in both groups. This is the first work evaluating and demonstrating the feasibility of near real-time VA/Q distribution measurements with the MIGET and the MMIMS methods.

Determining the accuracy of zero-flux and ingestible thermometers in the peri-operative setting Abstract Accurately monitoring peri-operative core temperature is a cornerstone of good practice. Relatively invasive devices such as oesophageal temperature probes and pulmonary artery catheters facilitate this, but are inappropriate for many patients. There remains a need for accurate monitors of core temperature that can be used in awake patients. This study compared the accuracy of two core temperature thermometers that can be used for this purpose: the 3M Bair Hugger™ Temperature Monitoring System Zero Flux Thermometer and the CorTempR™ Wireless Ingestible Temperature Sensor. Readings were compared with the oesophageal probe, the current intraoperative standard. Thirty patients undergoing elective surgical procedures under general anaesthesia were recruited. The ingestible sensor was ingested prior to induction of anaethesia, and post induction, the zero-flux electrode attached above the right eyebrow and oesophageal probe inserted. During surgery, the temperature on each device was recorded every minute. Measurements were compared using Bland–Altman analysis. The ingestible sensor experienced interference from use of diathermy and fluoroscopy in the operating theatre, rendering 39% of its readings unusable. These were removed from analysis. With remaining readings the bias compared with oesophageal probe was + 0.42 °C, with 95% limits of agreement − 2.4 °C to 3.2 °C. 75.4% of readings were within ± 0.5 °C of the OTP reading. The bias for the zero flux electrode compared to oesophageal probe was + 0.02 °C with 95% limits of agreement − 0.5 °C to 0.5 °C. 97.7% of readings were within ± 0.5 °C of the oesophageal probe. The study findings suggest the zero-flux thermometer is sufficiently accurate for clinical use, whereas the ingestible sensor is not. Trial registration The study was registered at http://www.clinicaltrials.gov, NCT Number: NCT02121574.

Acceptance of a propofol and remifentanil infusion dosing algorithm to optimize postoperative emergence and analgesia Abstract We implemented a pharmacokinetic/pharmacodynamic (PK/PD) based optimization algorithm recommending intraoperative Remifentanil and Propofol infusion rates to minimize time to emergence and maximize the duration of analgesia in a clinical setting. This feasibility study tested the clinical acceptance of the optimization algorithm’s recommendations during scoliosis surgical repair for 14 patients. Anesthesiologist accepted 359/394 (91%) of the recommendations given on the basis of the optimization algorithm. While following the optimization’s recommendations the anesthesiologist decreased Propofol infusions from an average of 164–135 mcg/kg/min [p = 0.002] and increased Remifentanil infusions from an average of 0.22–0.30 mcg/kg/min [p = 0.004]. The anesthesiologists appeared to accept and follow the recommendations from a PK/PD based optimization algorithm.