Cardiac index-guided therapy to maintain optimised postinduction cardiac index in high-risk patients having major open abdominal surgery: the multicentre randomised iPEGASUS trial.

BACKGROUND: It is unclear whether optimising intraoperative cardiac index can reduce postoperative complications. We tested the hypothesis that maintaining optimised postinduction cardiac index during and for the first 8 h after surgery reduces the incidence of a composite outcome of complications within 28 days after surgery compared with routine care in high-risk patients having elective major open abdominal surgery. METHODS: In three German and two Spanish centres, high-risk patients having elective major open abdominal surgery were randomised to cardiac index-guided therapy to maintain optimised postinduction cardiac index (cardiac index at which pulse pressure variation was <12%) during and for the first 8 h after surgery using intravenous fluids and dobutamine or to routine care. The primary outcome was the incidence of a composite outcome of moderate or severe complications within 28 days after surgery. RESULTS: We analysed 318 of 380 enrolled subjects. The composite primary outcome occurred in 84 of 152 subjects (55%) assigned to cardiac index-guided therapy and in 77 of 166 subjects (46%) assigned to routine care (odds ratio: 1.87, 95% confidence interval: 1.03-3.39, P=0.038). Per-protocol analyses confirmed the results of the primary outcome analysis. CONCLUSIONS: Maintaining optimised postinduction cardiac index during and for the first 8 h after surgery did not reduce, and possibly increased, the incidence of a composite outcome of complications within 28 days after surgery compared with routine care in high-risk patients having elective major open abdominal surgery. Clinicians should not strive to maintain optimised postinduction cardiac index during and after surgery in expectation of reducing complications. CLINICAL TRIAL REGISTRATION: NCT03021525.

Intraoperative haemodynamic monitoring and management of adults having non-cardiac surgery: Guidelines of the German Society of Anaesthesiology and Intensive Care Medicine in collaboration with the German Association of the Scientific Medical Societies.

Haemodynamic monitoring and management are cornerstones of perioperative care. The goal of haemodynamic management is to maintain organ function by ensuring adequate perfusion pressure, blood flow, and oxygen delivery. We here present guidelines on "Intraoperative haemodynamic monitoring and management of adults having non-cardiac surgery" that were prepared by 18 experts on behalf of the German Society of Anaesthesiology and Intensive Care Medicine (Deutsche Gesellschaft für Anästhesiologie und lntensivmedizin; DGAI).

Respiratory gating improves correlation between pulse wave transit time and pulmonary artery pressure in experimental pulmonary hypertension.

Objective. Since pulse wave transit time (PWTT) shortens as pulmonary artery pressure (PAP) increases it was suggested as a potential non-invasive surrogate for PAP. The state of tidal lung filling is also known to affect PWTT independently of PAP. The aim of this retrospective analysis was to test whether respiratory gating improved the correlation coefficient between PWTT and PAP.Approach. In each one of five anesthetized and mechanically ventilated pigs two high-fidelity pressure catheters were placed, one directly behind the pulmonary valve, and the second one in a distal branch of the pulmonary artery. PAP was raised using the thromboxane A2 analogue U46619 and animals were ventilated in a pressure controlled mode (I:E ratio 1:2, respiratory rate 12/min, tidal volume of 6 ml kg-1). All signals were recorded using the multi-channel platform PowerLab®. The arrival of the pulse wave at each catheter tip was determined using a MATLAB-based modified hyperbolic tangent algorithm and PWTT calculated as the time interval between these arrivals.Main results. Correlation coefficient for PWTT and mean PAP wasr= 0.932 for thromboxane. This correlation coefficient increased considerably when heart beats either at end-inspiration (r= 0.978) or at end-expiration (r= 0.985) were selected (=respiratory gating).Significance. The estimation of mean PAP from PWTT improved significantly when taking the respiratory cycle into account. Respiratory gating is suggested to improve for the estimation of PAP by PWTT.

Assessing volume responsiveness using right ventricular dynamic indicators of preload.

PURPOSE: Dynamic indicators of preload currently only do reflect preload requirements of the left ventricle. To date, no dynamic indicators of right ventricular preload have been established. The aim of this study was to calculate dynamic indicators of right ventricular preload and assess their ability to predict ventricular volume responsiveness. MATERIALS AND METHODS: The study was designed as experimental trial in 20 anaesthetized pigs. Micro-tip catheters and ultrasonic flow probes were used as experimental reference to enable measurement of right ventricular stroke volume and pulse pressure. Hypovolemia was induced (withdrawal of blood 20 ml/kg) and thereafter three volume-loading steps were performed. ROC analysis was performed to assess the ability of dynamic right ventricular parameters to predict volume response. RESULTS: ROC analysis revealed an area under the curve (AUC) of 0.82 (CI 95% 0.73-0.89; p < 0.001) for right ventricular stroke volume variation (SVVRV), an AUC of 0.72 (CI 95% 0.53-0.85; p = 0.02) for pulmonary artery pulse pressure variation (PPVPA) and an AUC of 0.66 (CI 95% 0.51-0.79; p = 0.04) for pulmonary artery systolic pressure variation (SPVPA). CONCLUSIONS: In our experimental animal setting, calculating dynamic indicators of right ventricular preload is possible and appears promising in predicting volume responsiveness.

The use of pulse pressure variation for predicting impairment of microcirculatory blood flow.

Dynamic parameters of preload have been widely recommended to guide fluid therapy based on the principle of fluid responsiveness and with regard to cardiac output. An equally important aspect is however to also avoid volume-overload. This accounts particularly when capillary leakage is present and volume-overload will promote impairment of microcirculatory blood flow. The aim of this study was to evaluate, whether an impairment of intestinal microcirculation caused by volume-load potentially can be predicted using pulse pressure variation in an experimental model of ischemia/reperfusion injury. The study was designed as a prospective explorative large animal pilot study. The study was performed in 8 anesthetized domestic pigs (German landrace). Ischemia/reperfusion was induced during aortic surgery. 6 h after ischemia/reperfusion-injury measurements were performed during 4 consecutive volume-loading-steps, each consisting of 6 ml kg-1 bodyweight-1. Mean microcirculatory blood flow (mean Flux) of the ileum was measured using direct laser-speckle-contrast-imaging. Receiver operating characteristic analysis was performed to determine the ability of pulse pressure variation to predict a decrease in microcirculation. A reduction of ≥ 10% mean Flux was considered a relevant decrease. After ischemia-reperfusion, volume-loading-steps led to a significant increase of cardiac output as well as mean arterial pressure, while pulse pressure variation and mean Flux were significantly reduced (Pairwise comparison ischemia/reperfusion-injury vs. volume loading step no. 4): cardiac output (l min-1) 1.68 (1.02-2.35) versus 2.84 (2.15-3.53), p = 0.002, mean arterial pressure (mmHg) 29.89 (21.65-38.12) versus 52.34 (43.55-61.14), p < 0.001, pulse pressure variation (%) 24.84 (17.45-32.22) versus 9.59 (1.68-17.49), p = 0.004, mean Flux (p.u.) 414.95 (295.18-534.72) versus 327.21 (206.95-447.48), p = 0.006. Receiver operating characteristic analysis revealed an area under the curve of 0.88 (CI 95% 0.73-1.00; p value < 0.001) for pulse pressure variation for predicting a decrease of microcirculatory blood flow. The results of our study show that pulse pressure variation does have the potential to predict decreases of intestinal microcirculatory blood flow due to volume-load after ischemia/reperfusion-injury. This should encourage further translational research and might help to prevent microcirculatory impairment due to excessive fluid resuscitation and to guide fluid therapy in the future.

Large Duodenal Hematoma Causing an Ileus after an Endoscopic Duodenal Biopsy in a 6-Year-Old Child: A Case Report.

Intramural duodenal hematoma (IDH) in children is a rare complication after esophagogastroduodenoscopy. It is commonly described in patients with additional disorders or risk factors, such as coagulopathy. We present a case of a previously healthy 6-year-old boy with a large obstructing intramural duodenal hematoma and concomitant pancreatitis after an elective esophagogastroduodenoscopy. The patient presented with typical symptoms of an IDH, such as abdominal pain and distension, nausea and vomiting. IDH was diagnosed using ultrasound and magnetic resonance imaging examination. Conservative management with gastric decompression using a nasogastric feeding tube, bowel rest, total parenteral nutrition and analgesia was performed. After three weeks, the patient was discharged from the hospital without any complaints. Interventional management of IDH in pediatric patients with a lack of response to conservative therapy or complicating IDH should be discussed in an interdisciplinary team.

Personalised haemodynamic management targeting baseline cardiac index in high-risk patients undergoing major abdominal surgery: a randomised single-centre clinical trial.

BACKGROUND: Despite several clinical trials on haemodynamic therapy, the optimal intraoperative haemodynamic management for high-risk patients undergoing major abdominal surgery remains unclear. We tested the hypothesis that personalised haemodynamic management targeting each individual's baseline cardiac index at rest reduces postoperative morbidity. METHODS: In this single-centre trial, 188 high-risk patients undergoing major abdominal surgery were randomised to either routine management or personalised haemodynamic management requiring clinicians to maintain personal baseline cardiac index (determined at rest preoperatively) using an algorithm that guided intraoperative i.v. fluid and/or dobutamine administration. The primary outcome was a composite of major complications (European Perioperative Clinical Outcome definitions) or death within 30 days of surgery. Secondary outcomes included postoperative morbidity (assessed by a postoperative morbidity survey), hospital length of stay, mortality within 90 days of surgery, and neurocognitive function assessed after postoperative Day 3. RESULTS: The primary outcome occurred in 29.8% (28/94) of patients in the personalised management group, compared with 55.3% (52/94) of patients in the routine management group (relative risk: 0.54, 95% confidence interval [CI]: 0.38 to 0.77; absolute risk reduction: -25.5%, 95% CI: -39.2% to -11.9%; P<0.001). One patient assigned to the personalised management group, compared with five assigned to the routine management group, died within 30 days after surgery (P=0.097). There were no clinically relevant differences between the two groups for secondary outcomes. CONCLUSIONS: In high-risk patients undergoing major abdominal surgery, personalised haemodynamic management reduces a composite outcome of major postoperative complications or death within 30 days after surgery compared with routine care. CLINICAL TRIAL REGISTRATION: NCT02834377.

Anesthesia for Patients Undergoing Peroral Endoscopic Myotomy Procedures: A Review of the Literature.

Idiopathic achalasia is a motility disorder of the esophagus with important implications on anesthesia and periprocedural management. As new and more complex treatment options develop, anesthesiologists are increasingly involved with these patients. The cardinal symptoms of achalasia are as follows: dysphagia, regurgitation, chest pain, and weight loss. Achalasia is also associated with an increased risk of aspiration. Patients are frequently treated by endoscopic botulinum toxin injections, pneumatic dilation of the lower esophageal sphincter, laparoscopic Heller myotomy, or peroral endoscopic myotomy (POEM). The POEM procedure is based on the concept of "natural orifice transluminal endoscopic surgery." Because the integrity of the esophageal wall is deliberately interrupted during POEM, the mediastinum and the peritoneal cavity may be exposed. Thus, the insufflated carbon dioxide frequently causes hypercapnia, tension capnoperitoneum, capnomediastinum, or pneumothoraces. An interdisciplinary team, skilled in diagnostics and emergency measures such as therapeutic hyperventilation, percutaneous abdominal needle decompression, or pleural drainage, is essential for the successful periprocedural management of POEM. POEM is one endoscopic procedure that requires general anesthesia. But neither anesthesia-specific care algorithms nor evidence-based recommendations are currently available for these patients. Because institutional experience varies broadly across the globe, this review examines anesthesia recommendations and perioperative management of POEM procedures based on 7 retrospective case series, 1 prospective study, and our personal experience.

Retrospective analysis of central venous catheters in elective intracranial surgery - Is there any benefit?

BACKGROUND: It remains unclear whether the use of central venous catheters (CVC) improves a patient's clinical outcome after elective intracranial supratentorial procedures. METHODS: This two-armed, single-center retrospective study sought to compare patients undergoing elective intracranial surgery with and without CVCs. Standard anaesthesia procedures were modified during the study period resulting in the termination of obligatory CVC instrumentation for supratentorial procedures. Peri-operative adverse events (AEs) were evaluated as primary endpoint. RESULTS: The data of 621 patients in total was analysed in this study (301 with and 320 without CVC). Patient characteristics and surgical procedures were comparable between both study groups. A total of 132 peri-operative AEs (81 in the group with CVC vs. 51 in the group without CVC) regarding neurological, neurosurgical, cardiovascular events and death were observed. CVC patients suffer from AEs almost twice as often as non CVC patients (ORadjusted = 1.98; 95%CI[1.28-3.06]; p = 0.002). Complications related to catheter placement (pneumothorax and arterial malpuncture) were observed in 1.0% of the cases. The ICU treatment period in patients with CVC was 22 (19;24) vs. 21 (19;24) hours (p = 0.413). The duration of hospital stay was also similar between groups (9 (7;13) vs. 8 (7;11) days, p = 0.210). The total time of ventilation (350 (300;440) vs. 335 (281;405) min, p = 0.003) and induction time (40 (35;50) vs. 30 (25;35) min, p<0.001) was found to be prolonged significantly in the group with CVCs. There were no differences found in post-operative inflammatory markers as well as antibiotic treatment. CONCLUSION: The data of our retrospective study suggests that patients undergoing elective neurosurgical procedures with CVCs do not demonstrate any additional benefits in comparison to patients without a CVC.

A case series on the value of tau and neurofilament protein levels to predict and detect delirium in cardiac surgery patients.

BACKGROUND: Delirium following cardiac surgery is a relevant complication in the majority of elderly patients but its prediction is challenging. Cardiopulmonary bypass, essential for many interventions in cardiac surgery, is responsible for a severe inflammatory response leading to neuroinflammation and subsequent delirium. Neurofilament light protein (NfL) and tau protein (tau) are specific biomarkers to detect neuroaxonal injury as well as glial fibrillary acidic protein (GFAP), a marker of astrocytic activation. METHODS: We thought to examine the perioperative course of these markers in a case series of each three cardiac surgery patients under off-pump cardiac arterial bypass without evolving delirium (OPCAB-NDEL), patients with a procedure under cardio-pulmonary bypass (CPB) without delirium (CPB-NDEL) and delirium after a CPB procedure (CPB-DEL). Delirium was diagnosed by the Confusion Assessment Method for the ICU and chart reviews. RESULTS: We observed increased preoperative levels of tau in patients with later delirium, whereas values of NfL and GFAP did not differ. In the postoperative course, all biomarkers increased multi-fold. NfL levels sharply increased in patients with CPB reaching the highest levels in the CPB-DEL group. CONCLUSION: Tau and NfL might be of benefit to identify patients in cardiac surgery at risk for delirium and to detect patients with the postoperative emergence of delirium.

Automated Ambulatory Blood Pressure Measurements and Intraoperative Hypotension in Patients Having Noncardiac Surgery with General Anesthesia: A Prospective Observational Study.

BACKGROUND: Normal blood pressure varies among individuals and over the circadian cycle. Preinduction blood pressure may not be representative of a patient's normal blood pressure profile and cannot give an indication of a patient's usual range of blood pressures. This study therefore aimed to determine the relationship between ambulatory mean arterial pressure and preinduction, postinduction, and intraoperative mean arterial pressures. METHODS: Ambulatory (automated oscillometric measurements at 30-min intervals) and preinduction, postinduction, and intraoperative mean arterial pressures (1-min intervals) were prospectively measured and compared in 370 American Society of Anesthesiology physical status classification I or II patients aged 40 to 65 yr having elective noncardiac surgery with general anesthesia. RESULTS: There was only a weak correlation between the first preinduction and mean daytime mean arterial pressure (r = 0.429, P < 0.001). The difference between the first preinduction and mean daytime mean arterial pressure varied considerably among individuals. In about two thirds of the patients, the lowest postinduction and intraoperative mean arterial pressures were lower than the lowest nighttime mean arterial pressure. The difference between the lowest nighttime mean arterial pressure and a mean arterial pressure of 65 mmHg varied considerably among individuals. The lowest nighttime mean arterial pressure was higher than 65 mmHg in 263 patients (71%). CONCLUSIONS: Preinduction mean arterial pressure cannot be used as a surrogate for the normal daytime mean arterial pressure. The lowest postinduction and intraoperative mean arterial pressures are lower than the lowest nighttime mean arterial pressure in most patients.

Muscular Ultrasound, Syndecan-1 and Procalcitonin Serum Levels to Assess Intensive Care Unit-Acquired Weakness.

BACKGROUND: Intensive care unit-acquired weakness (ICU-AW) is associated with poorer outcome of critically ill patients. Microcirculatory changes and altered vascular permeability of skeletal muscles might contribute to the pathogenesis of ICU-AW. Muscular ultrasound (MUS) displays increased muscle echogenicity, although its pathogenesis is uncertain. OBJECTIVE: We investigated the combined measurement of serum and ultrasound markers to assess ICU-AW and clinical patient outcome. METHODS: Fifteen patients and five healthy controls were longitudinally assessed for signs of ICU-AW at study days 3 and 10 using a muscle strength sum score. The definition of ICU-AW was based on decreased muscle strength assessed by the muscular research council-sum score. Ultrasound echogenicity of extremity muscles was assessed using a standardized protocol. Serum markers of inflammation and endothelial damage were measured. The 3-month outcome was assessed on the modified Rankin scale. RESULTS: ICU-AW was present in eight patients, and seven patients and the control subjects did not develop ICU-AW. The global muscle echogenicity score (GME) differed significantly between controls and patients (mean GME, 1.1 ± 0.06 vs. 2.3 ± 0.41; p = 0.001). Mean GME values significantly decreased in patients without ICU-AW from assessment 1 (2.30 ± 0.48) to assessment 2 (2.06 ± 0.45; p = 0.027), which was not observed in patients with ICU-AW. Serum levels of syndecan-1 at day 3 significantly correlated with higher GME values at day 10 (r = 0.63, p = 0.012). Furthermore, the patients' GME significantly correlated with mRS at day 100 (r = 0.67, p = 0.013). CONCLUSION: The combined use of muscular ultrasound and inflammatory biomarkers might be helpful to diagnose ICU-AW and to predict long-term outcome in critical illness.

Continuous Noninvasive Arterial Pressure Monitoring in Obese Patients During Bariatric Surgery: An Evaluation of the Vascular Unloading Technique (Clearsight system).

BACKGROUND: Continuous monitoring of arterial pressure is important in severely obese patients who are at particular risk for cardiovascular complications. Innovative technologies for continuous noninvasive arterial pressure monitoring are now available. In this study, we compared noninvasive arterial pressure measurements using the vascular unloading technique (Clearsight system; Edwards Lifesciences Corp, Irvine, CA) with invasive arterial pressure measurements (radial arterial catheter) in severely obese patients during laparoscopic bariatric surgery. METHODS: In 35 severely obese patients (median body mass index, 47 kg/m2), we simultaneously recorded noninvasive and invasive arterial pressure measurements over a period of 45 minutes. We compared noninvasive (test method) and invasive (reference method) arterial pressure measurements (sampling rate 1 Hz = 1/s) using Bland-Altman analysis (accounting for multiple measurements per subject), 4-quadrant plot/concordance analysis (2-minute interval, 5 mm Hg exclusion zone), and error grid analysis (calculating the proportions of measurements in risk zones A-E with A indicating no risk, B low risk, C moderate risk, D significant risk, and E dangerous risk for the patient due to the risk of wrong clinical interventions because of measurement errors). RESULTS: We observed a mean of the differences (±SD, 95% limits of agreement) between the noninvasively and invasively assessed arterial pressure values of 1.1 mm Hg (±7.4 mm Hg, -13.5 to 15.6 mm Hg) for mean arterial pressure (MAP), 6.8 mm Hg (±10.3 mm Hg, -14.4 to 27.9 mm Hg) for systolic arterial pressure, and 0.8 mm Hg (±6.9 mm Hg, -12.9 to 14.4 mm Hg) for diastolic arterial pressure. The 4-quadrant plot concordance rate (ie, the proportion of arterial pressure measurement pairs showing concordant changes to all changes) was 93% (CI, 89%-96%) for MAP, 93% (CI, 89%-97%) for systolic arterial pressure, and 88% (CI, 84%-92%) for diastolic arterial pressure. Error grid analysis showed that the proportions of measurements in risk zones A-E were 89.5%, 10.0%, 0.5%, 0%, and 0% for MAP and 93.7%, 6.0%, 0.3%, 0%, and 0% for systolic arterial pressure, respectively. CONCLUSIONS: During laparoscopic bariatric surgery, the accuracy and precision of the vascular unloading technique (Clearsight system) was good for MAP and diastolic arterial pressure, but only moderate for systolic arterial pressure according to Bland-Altman analysis. The system showed good trending capabilities. In the error grid analysis, >99% of vascular unloading technique-derived arterial pressure measurements were categorized in no- or low-risk zones.

Hemadsorption during cardiopulmonary bypass reduces interleukin 8 and tumor necrosis factor α serum levels in cardiac surgery: a randomized controlled trial.

BACKGROUND: Surgical trauma and cardiopulmonary bypass (CPB) are associated with the liberation of pro-inflammatory cytokines. With hemadsorption (Cytosorb®) during CPB, pro-inflammatory cytokines may be reduced and the inflammatory response may be decreased. METHODS: In this prospective, randomized single center study, serum cytokine levels of interleukin 8 (Il-8), interleukin 6 (Il-6) and tumor-necrosis-factor α (TNFα) were assessed in elective on-pump cardiac surgery patients with hemadsorption on CPB (study group [SG], N.=20) and without (control group [CG], N.=20). Cytokine levels were assessed prior to CPB, at the end of CPB, and 6 hours (h) and 24 h after the end of CPB, together with a hemodynamic assessment. Cardiac-Index (CI) was assessed with transcardiopulmonary thermodilution. RESULTS: For Il-8, significantly lower serum levels were observed in the SG compared to the CG at the end of CPB (P=0.008). In the SG, TNFα levels were also below those in the CG at both the end of and 6h after CPB (P=0.034). After 24 hours, TNFα levels were at baseline in both groups. No significant differences were found for Il-6. The CI was significantly higher in the SG at the end of CPB (P=0.025). However, there was no difference between both groups 6 h after CPB. CONCLUSIONS: This prospective study shows a significant reduction in pro-inflammatory cytokine levels of Il-8 and TNFα with hemadsorption in on-pump cardiac surgery whilst also demonstrating safety in its applications. However, the differences in cytokine levels and CI between patients treated with hemadsorption and those without were minor and of short duration.

Continuous noninvasive arterial blood pressure monitoring using the vascular unloading technology during complex gastrointestinal endoscopy: a prospective observational study.

The innovative vascular unloading technology (VUT) allows continuous noninvasive arterial blood pressure (AP) monitoring. We aimed to investigate whether the VUT enables AP changes to be detected earlier compared with intermittent AP monitoring in patients undergoing gastrointestinal endoscopy. In this prospective observational study, we recorded continuous AP measurements with the VUT (CNAP system; CNSystems Medizintechnik AG, Graz, Austria) and intermittent AP measurements with upper arm cuff oscillometry in 90 patients undergoing complex gastrointestinal endoscopy (Department of Interventional Endoscopy at the University Medical Center Hamburg-Eppendorf, Hamburg, Germany). A "hypotensive phase" was defined as a time period of at least 30 s during which ≥ 50% of the VUT-AP values were in a predefined range of hypotension, i.e., AP value a) ≥ 10% below the last oscillometric value and b) ≤ 65 mmHg for mean AP or ≤ 90 mmHg for systolic AP. In the 5-min-interval between two oscillometric measurements, one or more hypotensive phases were detected in 26 patients (29%) for mean AP and in 27 patients (30%) for systolic AP. Hypotensive phases had a mean duration of 195 ± 99 s for mean AP and 197 ± 97 s for systolic AP with a mean procedure duration of 36 (± 21) min. Continuous noninvasive AP monitoring using the VUT enables hypotensive phases to be detected earlier compared with intermittent AP monitoring during complex gastrointestinal endoscopy. These hypotensive phases may be missed or only belatedly recognized with intermittent AP monitoring. Continuous noninvasive AP measurement facilitates detecting hemodynamic instability more rapidly and therefore may improve patient safety.

Continuous Noninvasive Arterial Pressure Monitoring Using the Vascular Unloading Technique (CNAP System) in Obese Patients During Laparoscopic Bariatric Operations.

BACKGROUND: Increasing rates of obesity create new challenges for hemodynamic monitoring in the perioperative phase. Continuous monitoring of arterial pressure (AP) is important in severely obese patients who are at particular risk for cardiovascular complications. Innovative technologies for continuous noninvasive AP monitoring are now available. In this study, we aimed to compare continuous noninvasive AP measurements using the vascular unloading technique (CNAP system; CNSystems, Graz, Austria) compared with invasive AP measurements (radial arterial catheter) in severely obese patients during laparoscopic bariatric surgery. METHODS: In 29 severely obese patients (mean body mass index 48.1 kg/m), we simultaneously recorded noninvasive and invasive AP measurements over a period of 45 minutes and averaged the measurements using 10-second episodes. We compared noninvasive (test method) and invasive (reference method) AP measurements using Bland-Altman analysis and 4-quadrant plot/concordance analysis (2-minute interval). RESULTS: We observed a mean of the differences (±SD, 95% limits of agreement) between the AP values obtained by the CNAP system and the invasively assessed AP values of 7.9 mm Hg (±9.6 mm Hg, -11.2 to 27.0 mm Hg) for mean AP, 4.8 mm Hg (±15.8 mm Hg, -26.5 to 36.0 mm Hg) for systolic AP, and 9.5 mm Hg (±10.3 mm Hg, -10.9 to 29.9 mm Hg) for diastolic AP, respectively. The concordance rate was 97.5% for mean AP, 95.0% for systolic AP, and 96.7% for diastolic AP, respectively. CONCLUSIONS: In the setting of laparoscopic bariatric surgery, continuous noninvasive AP monitoring with the CNAP system showed good trending capabilities compared with continuous invasive AP measurements obtained with a radial arterial catheter. However, absolute CNAP- and arterial catheter-derived AP values were not interchangeable.

A comparison of volume clamp method-based continuous noninvasive cardiac output (CNCO) measurement versus intermittent pulmonary artery thermodilution in postoperative cardiothoracic surgery patients.

The CNAP technology (CNSystems Medizintechnik AG, Graz, Austria) allows continuous noninvasive arterial pressure waveform recording based on the volume clamp method and estimation of cardiac output (CO) by pulse contour analysis. We compared CNAP-derived CO measurements (CNCO) with intermittent invasive CO measurements (pulmonary artery catheter; PAC-CO) in postoperative cardiothoracic surgery patients. In 51 intensive care unit patients after cardiothoracic surgery, we measured PAC-CO (criterion standard) and CNCO at three different time points. We conducted two separate comparative analyses: (1) CNCO auto-calibrated to biometric patient data (CNCObio) versus PAC-CO and (2) CNCO calibrated to the first simultaneously measured PAC-CO value (CNCOcal) versus PAC-CO. The agreement between the two methods was statistically assessed by Bland-Altman analysis and the percentage error. In a subgroup of patients, a passive leg raising maneuver was performed for clinical indications and we present the changes in PAC-CO and CNCO in four-quadrant plots (exclusion zone 0.5 L/min) in order to evaluate the trending ability of CNCO. The mean difference between CNCObio and PAC-CO was +0.5 L/min (standard deviation ± 1.3 L/min; 95% limits of agreement -1.9 to +3.0 L/min). The percentage error was 49%. The concordance rate was 100%. For CNCOcal, the mean difference was -0.3 L/min (±0.5 L/min; -1.2 to +0.7 L/min) with a percentage error of 19%. In this clinical study in cardiothoracic surgery patients, CNCOcal showed good agreement when compared with PAC-CO. For CNCObio, we observed a higher percentage error and good trending ability (concordance rate 100%).

Assessment of the efficiency of language interpreter services in a busy surgical and procedural practice.

BACKGROUND: Surgical and procedural patient care settings require efficient patient flow. The primary goal of this study was to assess use and efficiency of language services for our limited English proficiency (LEP) patients undergoing surgical and outpatient procedures. METHODS: Patient language services needs were recorded from our operating room and procedural locations over a two and a half month period in 2016. Time from in-person interpreter request to arrival was recorded. Frequency of language service modality used and reason for telephone and professional video remote interpreting (VRI) rather than in person professional services was queried. RESULTS: Mean time from in-person interpreter request until arrival was 19 min. Variation was high. No cases were cancelled due to lack of available interpretive services and no LEP patient underwent a procedure without requested interpretative service assistance. CONCLUSIONS: Time for in person professional interpreter assistance was short but highly variable. Access to telephone interpretive services and VRI services ensured assistance when in person interpreters were immediately unavailable. With the numbers of LEP patients increasing over time along with any new mandates for providing language assistance, the stress on hospital patient service units and the financial implications for many health care facilities will likely continue as challenges.

Anesthetic considerations for patients with esophageal achalasia undergoing peroral endoscopic myotomy: a retrospective case series review.

PURPOSE: Peroral endoscopic myotomy (POEM) is a novel technique for treating esophageal achalasia. During POEM, carbon dioxide (CO2) is insufflated to aid surgical dissection, but it may inadvertently track into surrounding tissues, causing systemic CO2 uptake and tension capnoperitoneum. This in turn may affect cardiorespiratory function. This study quantified these cardiorespiratory effects and treatment by hyperventilation and percutaneous abdominal needle decompression (PND). METHODS: One hundred and seventy-three consecutive patients who underwent POEM were included in this four-year retrospective study. Procedure-related changes in peak inspiratory pressure (pmax), end-tidal CO2 levels (etCO2), minute ventilation (MV), mean arterial pressure (MAP), and heart rate (HR) were analyzed. We also quantified the impact of PND on these cardiorespiratory parameters. RESULTS: During the endoscopic procedure, cardiorespiratory parameters increased from baseline: pmax 15.1 (4.5) vs 19.8 (4.7) cm H2O; etCO2 4.5 (0.4) vs 5.5 (0.9) kPa [34.0 (2.9) vs 41.6 (6.9) mmHg]; MAP 73.9 (9.7) vs 99.3 (15.2) mmHg; HR 67.6 (12.4) vs 85.3 (16.4) min-1 (P < 0.001 for each). Hyperventilation [MV 5.9 (1.2) vs 9.0 (1.8) L·min-1, P < 0.001] was applied to counteract iatrogenic hypercapnia. Individuals with tension capnoperitoneum treated with PND (n = 55) had higher peak pmax values [22.8 (5.7) vs 18.4 (3.3) cm H2O, P < 0.001] than patients who did not require PND. After PND, pmax [22.8 (5.7) vs 19.9 (4.3) cm H2O, P = 0.045] and MAP [98.2 (16.3) vs 88.6 (11.8) mmHg, P = 0.013] decreased. Adverse events included pneumothorax (n = 1), transient myocardial ischemia (n = 1), and subcutaneous emphysema (n = 49). The latter precluded immediate extubation in eight cases. Postanesthesia care unit (PACU) stay was longer in individuals with subcutaneous emphysema than in those without [74.9 min (34.5) vs 61.5 (26.8 min), P = 0.007]. CONCLUSION: Carbon dioxide insufflation during POEM produces systemic CO2 uptake and increased intra-abdominal pressure. Changes in cardiorespiratory parameters include increased pmax, etCO2, MAP, and HR. Hyperventilation and PND help mitigate some of these changes. Subcutaneous emphysema is common and may delay extubation and prolong PACU stay.

Reduction of clinically irrelevant alarms in patient monitoring by adaptive time delays.

The problem of high rates of false alarms in patient monitoring in anesthesiology and intensive care medicine is well known but remains unsolved. False alarms desensitize the medical staff, leading to ignored true alarms and reduced quality of patient care. A database of intra-operative monitoring data was analyzed to find characteristic alarm patterns. The original data were re-evaluated to find relevant events and to rate the severity of these events. Based on this analysis an adaptive time delay was developed that individually delays the alarms depending on the grade of threshold deviation. The conventional threshold algorithm led to 4893 alarms. 3515 (71.84 %) of these alarms were annotated as clinically irrelevant. In total 81.0 % of all clinically irrelevant alarms were caused by only mild and/or brief threshold violations. We implemented the new algorithm for selected parameters. These parameters equipped with adaptive validation delays led to 1729 alarms. 931 (53.85 %) alarms were annotated as clinically irrelevant. 632 alarms indicated the 645 clinically relevant events. The positive predictive value of occurring alarms improved from 28.16 % (conventional algorithm) to 46.15 % (new algorithm). 13 events were missed. The false positive alarm reduction rate of the algorithm ranged from 33 to 86.75 %. The overall reduction was 73.51 %. The implementation of this algorithm may be able to suppress a large percentage of false alarms. The effect of this approach has not been demonstrated but shows promise for reducing alarm fatigue. Its safety needs to be proven in a prospective study.