Noninvasive Assessment of Arterial Pulse-Pressure Variation During General Anesthesia: Clinical Evaluation of a New High-Fidelity Upper Arm Cuff

OBJECTIVES

To compare noninvasive pulse-pressure variation (PPV) measurements obtained from a new high-fidelity upper arm cuff using a hydraulic coupling technique to corresponding intraarterial PPV measurements.

DESIGN

The authors used prospective multicenter comparison and development studies for the new high-fidelity upper arm cuff.

SETTING

The study was performed in the departments of Anesthesiology at the Ludwig-Maximilians-Universität München Hospital, the University Hospital of Bonn, and the RoMed Hospital in Rosenheim (all Germany).

PARTICIPANTS

A total of 153 patients were enrolled, undergoing major abdominal surgery or neurosurgery with mechanical ventilation. For the evaluation of PPV, 1,467 paired measurements in 107 patients were available after exclusion due to predefined quality criteria.

INTERVENTIONS

Simultaneous measurements of PPV were performed from a reference femoral arterial catheter (PPV_ref) and the high-fidelity upper arm cuff (PPV_cuff). The new device uses a semirigid conical shell. It incorporates a hydraulic sensor pad with a pressure transducer, leading to a tissue pressure-pulse contour with all characteristics of an arterial- pulse contour.

MEASUREMENTS AND MAIN RESULTS

The comparative analysis of the included measurements showed that PPV_ref and PPV_cuff were closely correlated (r = 0.92). The mean of the differences between PPV_ref and PPV_cuff was 0.1 ± 2.0%, with 95% limits of agreement between -4.1% and 3.9%. To track absolute changes in PPV >2%, the concordance rate between the 2 methods was 93%.

CONCLUSIONS

The new high-fidelity upper arm cuff method provided a clinically reliable estimate of PPV.

Evaluation of continuous ampicillin/sulbactam infusion in critically ill patients

Continuous infusion (CI) of beta-lactam-antibiotics may improve pharmacodynamics in critically ill patients, but resulting concentrations have not been studied. Therapeutic drug monitoring is increasingly used to ensure antibiotic concentration. The aim of this study is to evaluate therapeutic ampicillin/sulbactam concentrations of a continuous infusion regimen.

METHODS

Medical records of all patients admitted to ICU between January 2019 and December 2020 were retrospectively reviewed. Each patient received a 2/1 g ampicillin/sulbactam loading dose, followed by a continuous infusion of 8/4 g per 24 h. Ampicillin serum concentrations were measured. Main outcomes were reaching of plasma concentrations breakpoint defined by minimum inhibitory concentration (MIC at 8 mg/l) and 4-fold MIC (MIC at 32 mg/l) during steady state of CI.

RESULTS

In 50 patients a total of 60 concentration measurements were performed. The first concentration was measured after a median of 29 h (IQR 21-61 h). Mean ampicillin concentration was 62.6 ± 39.1 mg/l. Furthermore, serum concentrations exceeded the defined MIC breakpoint in all measurements (100 %) and were above the 4-fold MIC in 43 analyses (71.1 %). However, patients suffering from acute kidney injury exhibited significant higher serum concentrations (81.1 ± 37.7 mg/l vs. 38.2 ± 24.8 mg/l; p < 0.001). Also, there was a negative correlation between ampicillin serum concentrations and GFR (r = -0.659; p < 0.001).

CONCLUSION

The described dosing regimen for ampicillin/sulbactam is safe with respect to the defined MIC breakpoints for ampicillin, and continuous subtherapeutic concentration is unlikely. However, with impaired renal function drug accumulation occurs, and with increased renal clearance, drug levels can be below the 4-fold MIC breakpoint.

Preoperative cerebral oxygenation in high-risk noncardiac surgical patients: an observational study on postoperative mortality and complications

Near Infrared Spectroscopy (NIRS) has become widely accepted to evaluate regional cerebral oxygen saturation (rScO2), potentially acting as a surrogate parameter of reduced cerebral oxygen delivery or increased consumption. Low preoperative rScO2 is associated with increased postoperative complications after cardiac surgery. However, its universal potential in pre-anesthesia risk assessment remains unclear. Therefore, we investigated whether low preoperative rScO2 is indicative of postoperative complications and associated with poor outcomes in noncardiac surgical patients. We prospectively enrolled 130 patients undergoing high-risk noncardiac surgery. During pre-anesthesia evaluation, baseline rScO2 was recorded with and without oxygen supplementation. The primary endpoint was 30-day mortality, while secondary endpoints were postoperative myocardial injury, respiratory complications, and renal failure. We further evaluated the impact of body position and preoperative hemoglobin (Hb) concentration on rScO2. Of the initially enrolled 130 patients, 126 remained for final analysis. Six (4.76%) patients died within 30 postoperative days. 95 (75.4%) patients were admitted to the ICU. 32 (25.4%) patients suffered from major postoperative complications. There was no significant association between rScO2 and 30-day mortality or secondary endpoints. Oxygen supplementation induced a significant increase of rScO2. Furthermore, Hb concentration correlated with rScO2 values and body position affected rScO2. No significant association between rScO2 values and NYHA, LVEF, or MET classes were observed. Preoperative rScO2 is not associated with postoperative complications in patients undergoing high-risk noncardiac surgery. We speculate that the discriminatory power of NIRS is insufficient due to individual variability of rScO2 values and confounding factors.

Point-of-Care Ultrasound-Guided Protocol to Confirm Central Venous Catheter Placement in Pediatric Patients Undergoing Cardiothoracic Surgery: A Prospective Feasibility Study

Background: Central venous catheters (CVC) are commonly required for pediatric congenital cardiac surgeries. The current standard for verification of CVC positioning following perioperative insertion is postsurgical radiography. However, incorrect positioning may induce serious complications, including pleural and pericardial effusion, arrhythmias, valvular damage, or incorrect drug release, and point of care diagnostic may prevent these serious consequences. Furthermore, pediatric patients with congenital heart disease receive various radiological procedures. Although relatively low, radiation exposure accumulates over the lifetime, potentially reaching high carcinogenic values in pediatric patients with chronic disease, and therefore needs to be limited. We hypothesized that correct CVC positioning in pediatric patients can be performed quickly and safely by point-of-care ultrasound diagnostic. Methods: We evaluated a point-of-care ultrasound protocol, consistent with the combination of parasternal craniocaudal, parasternal transversal, suprasternal notch, and subcostal probe positions, to verify tip positioning in any of the evaluated views at initial CVC placement in pediatric patients undergoing cardiothoracic surgery for congenital heart disease. Results: Using the combination of the four views, the CVC tip could be identified and positioned in 25 of 27 examinations (92.6%). Correct positioning was confirmed via chest X-ray after the surgery in all cases. Conclusions: In pediatric cardiac patients, point-of-care ultrasound diagnostic may be effective to confirm CVC positioning following initial placement and to reduce radiation exposure.

Pediatric emergence delirium is linked to increased early postoperative negative behavior within two weeks after adenoidectomy: an observational study

BACKGROUND

The aim of this prospective multicenter observational study was to measure the incidence of postoperative pediatric emergence delirium and to investigate the occurrence of early postoperative negative behavior within two weeks after outpatient adenoidectomy in preschool children.

METHODS

The study comprised 222 patients (1-7 years of age). All children received a multimodal anesthesia based on total intravenous anesthesia with propofol and remifentanil in combination with piritramid (0.1 mg.kg-1), ibuprofen (10 mg.kg-1), dexamethason (0.15 mg.kg-1), and ketanest S (0.1 mg.kg-1). We evaluated emergence delirium using the Pediatric Anesthesia Emergence Delirium Scale (PAED) at different predefined time points during the recovery period. Emergence delirium was defined as a PAED score ≥ 9 for the first three criteria. Additionally, we defined early postoperative negative behavior to be present when at least 5 of 27 criteria of the post hospitalization behavior questionnaire were positive.

RESULTS

The incidence of emergence delirium following our anesthetic regime was 23%. The incidence of early postoperative negative behavior was significantly higher among patients with emergence delirium (24% vs. 11%, p = 0.04). The two categories, "sleep disturbance" and "separation anxiety", tested within the questionnaire for early postoperative negative behavior, were identified as the most common postoperative negative behavioral changes.

CONCLUSION

Emergence delirium not only plays a role immediately after surgery but is also linked to early postoperative negative behavior within two weeks after outpatient adenoidectomy. Parents should be informed that early postoperative negative behavior may occur in 1 out of 4 patients if emergence delirium was present postoperatively.

TRIAL REGISTRATION

DRKS - German Clinical Trial Register ID: DRKS00013121.

A National Survey: Current Clinical Practice in Pediatric Anesthesia for Congenital Heart Surgery

BACKGROUND

Providing anesthesia for pediatric patients undergoing congenital cardiac surgery is complex and requires profound knowledge and clinical experience. Prospective studies on best anesthetic management are missing, partially due to different standards. The aim of the present study was to survey the current standard practice in anesthetic management in pediatric cardiac surgical centers in Germany.

METHODS

All 78 cardiac surgical centers in Germany were reviewed for a congenital cardiac surgery program. Centers with an active program for congenital cardiac surgery were interviewed to participate in the present online questionnaire to assess their current anesthetic practice.

RESULTS

Twenty-seven German centers running an active program for congenital heart surgery were identified, covering more than 3,000 pediatric cardiac surgeries annually. Of these centers, 96.3% (26/27) participated in our survey. Standard induction agents were etomidate in 26.9% (7/26), propofol in 19.2% (5/26), a combination of benzodiazepines and ketamine in 19.2% (5/26), and barbiturates in 11.5% (3/26). General anesthesia was preferentially maintained using volatile agents, 61.5% (16/26), with sevoflurane being the most common volatile agent within this group, 81.2% (13/16). Intraoperative first-choice/first-line inotropic drug was epinephrine, 53.8% (14/26), followed by milrinone, 23.1% (6/26), and dobutamine 15.4% (4/26). Fast-track programs performing on-table extubation depending on the type of surgical procedure were established at 61.5% (16/26) of the centers.

CONCLUSION

This study highlights the diversity of clinical standards in pediatric cardiac anesthesia for congenital cardiac surgery in Germany.

Low-body-perfusion via an arterial sheath reduces inflammation after aortic arch reconstruction surgery

Pediatric cardiac surgeries involving aortic arch reconstruction are complex and require long cardiopulmonary bypass (CPB) times with deep hypothermic circulatory arrest (DHCA). Selective perfusion techniques have been developed to prevent the deleterious consequences of DHCA associated hypoperfusion. The effectivity of low body perfusion through cannulation of the femoral artery with an arterial sheath remains to be elucidated. We compared perfusion and inflammation in patients receiving selective antegrade cerebral perfusion (ACP) only to low body perfusion (LBP) in addition to ACP during DHCA for aortic arch reconstruction surgery. There was no difference in patient characteristics, cardiac pathologies, or performed procedures between ACP and LBP groups. Lactate levels increased after cardiac arrest in both groups. However, lactate levels were lower after 1 h reperfusion, at the end of extracorporeal circulation (ECC), and after surgery in LBP group compared to ACP only. Furthermore, creatinine was increased in ACP group on postoperative day 1 compared to LBP group but no acute kidney injury was observed in any group. IL-6 concentration increased in ACP group, while remained unchanged in LBP group compared to pre surgical values and were significantly lower compared to ACP group on postoperative days 1 and 2. LBP via an arterial sheath during cardiac arrest for aortic arch reconstruction surgery in addition to ACP, improves post ECC tissue perfusion as indicated by lower lactate levels and reduces creatinine levels suggesting milder kidney injury. LBP seems to prevent postoperative inflammation through a reduction in procedural duration or enhanced perfusion and thereby improves the outcome after aortic arch reconstruction surgery.

Improvement of polytrauma management-quality inspection of a newly introduced course concept

RATIONALE, AIMS, AND OBJECTIVES

A systematic literature search for training course concepts for care of severely injured and severely ill patients respecting improvement of process and outcome yielded little data. For several years, the University Hospital of Bonn has hosted a shock-room management course which, on the one hand, communicates human factor aspects and, on the other hand, pursues interdisciplinary and interprofessional team training. The Bonn shock-room management course (BSM-course®) differs from other courses in both format and principles. The aim of this study was to evaluate the quality of the structure of the course based on course evaluations of participants and its impact on the quality of the process and results for polytrauma care.

METHODS

Single-center retrospective evaluation study (2011 to 2014). It was based on data from simulator training and records from the German Trauma Registry (DGU)®.

RESULTS

Subjective evaluation of participants (n = 188) of the structure quality of Bonn's shock-room management course was overall positive. Objective measures of course participant performance also improved during simulation training (P = 0.012). An increasing number of trained employees also had a positive influence in reducing process time for shock-room care. Further, the course likewise had a positive impact on documentation quality (degree of completion), with regard to 4 relevant predictive parameters. Early mortality during the first 24 hours remained constant at 6.0-6.5% between 2011 and 2013, yet it decreased to 3.1% in 2014.

CONCLUSION

The BSM-course® represents a symbiosis of horizontal team approach of trauma care and human factor training. The course format is able to ensure interdisciplinary and interprofessional team training with a high degree of efficiency. Furthermore, the presented work shows that a modern course concept can improve the quality of trauma care.

The provision of pediatric cardiac anesthesia services in Germany: current status of structural and personnel organization

BACKGROUND

Anesthesia for pediatric cardiac surgery requires a high level of expert knowledge. There are currently no recommendations and standards for anesthetic management for congenital cardiac surgery in Germany.

AIM

The aim of the present study was to assess the current status of structural and personnel anesthetic standards at pediatric cardiac surgery centers in Germany.

METHODS

All cardiac surgical centers in Germany were reviewed for an active program for congenital heart surgery. Centers with an active program were invited to respond to an online survey. The questionnaire containing 55 items in 16 categories assessed current practice in pediatric cardiac anesthesia.

RESULTS

An active program for pediatric cardiac surgery was identified at 27 centers. The response rate to the survey was 96.3%. A specialized group of anesthesiologists for pediatric cardiac anesthesia was reported from 26 centers (92.3%). The mean size of this group was 4.8 anesthesiologists per center. However, the annual case load of centers and relative annual case load per specialized anesthesiologist varied considerably between 12.5 and 250. Nonanesthesiologists performed sedation and general anesthesia for diagnostic and therapeutic interventions outside the operating theater in children with congenital heart diseases in 24 centers (77%). Although special equipment, for example, pediatric TEE, near-infrared spectroscopy, and devices for mechanical auto transfusion were available in most centers, their routine use was not always part of standard operating procedures. The proposal for mean adequate training in pediatric cardiac anesthesia as estimated by the participating centers was 10.8 months.

CONCLUSION

The present study represents the current structural situation for anesthesia at German pediatric cardiac surgery centers.

[Neglected, lonely and sick - the social breakdown : A special patient group in the emergency department]

BACKGROUND

The emergency department (ED) is increasingly becoming the primary care unit of patients who are no longer able to meet the necessary minimum requirements for a healthy life. In the emergency medical care of these patients, fixation errors and stereotyped thinking can distract from serious illnesses, which can be tended by emergency medicine. This group of patients, with their multifactorial problems, represents a special challenge for the staff of the ED. The aim of this study is to improve the quality of the care for a special patient group.

MATERIALS AND METHODS

A monocentric retrospective observation study was conducted at the University Hospital Bonn (UKB). On the basis of case studies, the emergency medical care of this special patient group was examined in the ED.

RESULTS

Over the period of 7 years (2009 to 2016), 17 patients in a state of total neglect could be examined. The endpoints identified, during the emergency care, are the therapy of life-threatening diseases, laboratory pathologies, introduction of infectious protective measures, initiation of diagnostic measures, measures to be initiated within different departments (operating room, intensive care unit) and outcome.

CONCLUSION

Patients in a state of total neglect require interdisciplinary primary care at a hospital with extended care structures. The apparent primary impression of these patients must not lead to a fixation error. Due to the often not obtainable history of the patient's and the complex appearance of these patients, the evaluation should be carried out according to a defined algorithm in the emergency room.

Prevention and Therapy of Pediatric Emergence Delirium: A National Survey

INTRODUCTION

Although pediatric emergence delirium (ED) is common, preventive and therapeutic pharmacological treatment is the matter of an international controversial discussion and evidence on different options is partially vague.

OBJECTIVE

We therefore examined clinical routine in prevention strategies and postoperative therapy of ED with respect to clinical experience in pediatric anesthesia.

METHODS

A web-based survey was developed investigating routine management (prevention and treatment) of ED, facility structure, and patient population. The link was sent to all enlisted members of the German Society of Anesthesiology.

RESULTS

We analyzed 1229 questionnaires. Overall, 88% reported ED as a relevant clinical problem; however, only 5% applied assessment scores to define ED. Oral midazolam was reported as standard premedication by 84% of respondents, the second largest group was 'no premedication' (5%). The first choice prevention strategy was to perform total intravenous (propofol) anesthesia (63%). The first choice therapeutic pharmacological treatment depended on clinical experience. Therapeutic propofol was preferentially chosen by more experienced anesthesiologists (5 to >20 patients per week, n = 538), while lesser experienced colleagues (<5 patients per week, n = 676) preferentially applied opioids. Dexmedetomidine (1%) and non-pharmacological (2%) therapy were rarely stated. The highest satisfaction levels for pharmacological therapy of ED were attributed to propofol.

CONCLUSIONS

Propofol is the preferred choice for pharmacological prevention and treatment of ED among German anesthesiologists. Further therapy options as well as alternatives to a midazolam-centered premedication procedure are underrepresented.

A rare case of direct tumor extension to the right ventricle

We report the case of a 72-year-old woman with signs of pulmonary embolism and right heart failure. Echocardiographic imaging and computed tomography revealed a mass within the inferior vena cava reaching from the head of the pancreas to the right ventricle. From standard imaging procedures and clinical findings alone, differentiation of a cardiac thrombus from a metastatic tumor mass was difficult. After resection of the intravascular tumor, histopathologic analysis confirmed a metastasis of primary ductal pancreatic adenocarcinoma. This is a report of a case of mucinous adenocarcinoma of the pancreas reaching the heart by continuous intravascular spreading.