[Focused Transthoracic Echocardiography in the Perioperative Setting]. / Die fokussierte transthorakale Echokardiografie in der perioperativen Versorgung.

With focused transthoracic echocardiography (TTE) we rapidly and non-invasively receive up-to-date information on a patient's hemodynamic status. These can subsequently influence our therapy and thus our risk management. Postoperatively, TTE has proved its worth as an examination method in the recovery room and in the intensive care unit to promptly diagnose life-threatening causes of circulatory depression. Acute pathology such as a pericardial tamponade or fulminant pulmonary artery embolism can be detected quickly and thus possibly time-consuming transport to a CT can be avoided. Also, preoperatively, the use of TTE may be useful for assessing volume status, pumping function, or hemodynamically relevant heart defects. Especially in surgical interventions with a high perioperative risk of complications, these findings can be incorporated into a goal-directed therapy. Corresponding algorithms for enhanced hemodynamic monitoring and volume management already exist in many areas, but they are often not consistently implemented in the processes of their own clinic. In this article, we demonstrate the utility and relevance of TTE hemodynamic evaluation at every stage of patient care. We also present a possible algorithm for the care of critically ill patients, based on the main transthoracic and hemodynamic measurements. It is intended to provide assistance in the meaningful use of TTE in everyday clinical practice and especially for those on on-call duty.

Feasibility and Impact of Focused Intraoperative Transthoracic Echocardiography on Management in Thoracic Surgery Patients: An Observational Study.

OBJECTIVES: Intraoperative focused transthoracic echocardiography (TTE) is feasible and has an effect on the management of hemodynamically unstable surgical patients. Furthermore, in noncardiac thoracic surgery, TTE might provide additional information for hemodynamic treatment. Transthoracic accessibility during thoracic surgical interventions is assumed to be difficult. For patients positioned on their right side, a modified subcostal transthoracic view might be helpful. DESIGN: A prospective observational study. SETTING: Single-center university hospital. PARTICIPANTS: The study comprised 105 consecutive patients undergoing noncardiac thoracic surgery. INTERVENTIONS: Focused TTE was performed during anesthetic induction after intubation for mechanical ventilation. Intraoperative focused TTE, after positioning and draping for surgery, was attempted again for all 105 patients. Changes in patient management due to the results of the TTE were documented and analyzed. MEASUREMENTS AND MAIN RESULTS: Presurgical TTE with mechanical ventilation was applied successfully in 98.1% of 105 patients. Intraoperative imaging was successful in 90 patients (85.7%). Results of intraoperative TTE led to the modification of perioperative management in 39 patients (37.1%), 20 (22.0%) of these during surgery. CONCLUSIONS: TTE in noncardiac thoracic surgery is feasible using a modified subcostal view and has an effect on hemodynamic management in a considerable number of patients.

Risk perception of blood transfusions - a comparison of patients and allied healthcare professionals.

BACKGROUND: Due to an increasing demand in health care services plans to substitute selective physician-conducted medical activities have become attractive. Because administration of a blood transfusion is a highly standardized procedure, it might be evaluated if obtaining a patient's consent for a blood transfusion can be delegated to allied healthcare professionals. Physicians and patients perceive risks of transfusions differently. However, it is unknown how allied healthcare professionals perceive risks of transfusion-associated adverse events. METHODS: Patients (n = 506) and allied healthcare professionals (n = 185) of an academic teaching hospital were asked to quantify their concerns about transfusions including five predefined transfusion-associated risks and their incidences. RESULTS: Blood transfusions were considered to be generally harmful by 10.9% of patients and 14.6% of caregivers (P = 0.180). Among all surveyed patients, 36.8% were worried about infection-transmissions (caregivers: 27.6%; P = 0.024). Compared to 5.4% of caregivers, 13.6% of patients believed infection-transmission was a frequent complication (P = 0.003). Caregivers ranked the risks of receiving an AB0-mismatch transfusion (caregivers: 29.7% vs. PATIENTS: 19.2%, P = 0.003) or a transfusion-associated allergic reaction (caregivers: 17.3% vs. PATIENTS: 11.1%, P = 0.030) significantly higher than patients and were aware of the high incidence of transfusion-associated fever (caregivers: 17.8% vs. PATIENTS: 8.3%, P < 0.001). CONCLUSION: A significant part of interviewees perceived transfusions as a general health hazard. Patients perceived infection-transmissions as the most frequent and greatest transfusion-associated threat while caregivers focused on fatal AB0-mismatch transfusions and allergic reactions. Understanding the patients' main concerns about blood transfusions and considering that these concerns might differ from the view of healthcare professionals might improve the process of shared decision making.

Recovery and prediction of postoperative muscle power - is it still a problem?

BACKGROUND: In the postoperative period, immediate recovery of muscular power is essential for patient safety, but this can be affected by anaesthetic drugs, opioids and neuromuscular blocking agents (NMBA). In this cohort study, we evaluated anaesthetic and patient-related factors contributing to reduced postoperative muscle power and pulse oximetric saturation. METHODS: We prospectively observed 615 patients scheduled for minor surgery. Premedication, general anaesthesia and respiratory settings were standardized according to standard operating procedures (SOP). If NMBAs were administered, neuromuscular monitoring was applied to establish a Train of four (TOF)-Ratio of >0.9 before extubation. After achieving a modified fast track score > 10 at 4 time points up to 2 h postoperatively, we measured pulse oximetric saturation and also static and dynamic muscle power, using a high precision digital force gauge. Loss of muscle power in relation to the individual preoperative baseline value was analysed in relation to patient and anaesthesia-related factors using the T-test, simple and multiple stepwise regression analysis. RESULTS: Despite having achieved a TOF ratio of >0.9 a decrease in postoperative muscle power was detectable in most patients and correlated with reduced postoperative pulse oximetric saturation. Independent contributing factors were use of neuromuscular blocking agents (p < 0.001), female gender (p = 0.001), TIVA (p = 0.018) and duration of anaesthesia >120 min (p = 0.019). CONCLUSION: Significant loss of muscle power and reduced pulse oximetric saturation are often present despite a TOF-Ratio > 0.9. Gender differences are also significant. A modified fast track score > 10 failed to predict recovery of muscle power in most patients. TRIAL REGISTRATION: German Clinical Trial Register DRKS-ID DRKS00006032 ; Registered: 2014/04/03.

Impact of Focused Intraoperative Transthoracic Echocardiography by Anesthesiologists on Management in Hemodynamically Unstable High-Risk Noncardiac Surgery Patients.

OBJECTIVES: Focused transthoracic echocardiography (TTE) is used perioperatively for surgical patients. Intraoperative application of TTE is feasible, but its benefits remain unclear. The intention of this study was to investigate the effect of intraoperative TTE on the management of high-risk noncardiac surgery patients. DESIGN: A prospective interventional study. SETTING: Single-center university hospital. PARTICIPANTS: Fifty consecutive hemodynamically unstable high-risk patients anesthetized for noncardiac surgery. INTERVENTIONS: Focused TTE was performed on hemodynamically unstable anesthetized patients whenever circulatory instability (defined as hypotension or low cardiac output) occurred intraoperatively. A cardiac output monitoring system using pulse contour analysis was established before induction of anesthesia. The intended therapy for stabilizing the patient was documented; however, the management actually administered was guided by the results of the TTE. Differences between the 2 lines of management were documented and analyzed. MEASUREMENTS AND MAIN RESULTS: Intraoperative TTE was applied successfully in all 50 unstable patients. In 33 patients (66%, 95% confidence interval, 52.11-77.61) TTE led to a change of management. Altogether, 82 episodes of hemodynamic instability were recorded, including 38 episodes (46.34%, 95% confidence interval, 35.95-57.06) in which TTE led to a change of treatment. The most common pathologic finding was hypovolemia (66%); in contrast, in 22%, right-heart overload or right-heart failure (4%) was detected. CONCLUSIONS: Focused TTE by anesthesiologists can provide new information that may alter the hemodynamic management of unstable high-risk noncardiac surgery patients in the operating room.

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.

Occurrence of rapid eye movement sleep deprivation after surgery under regional anesthesia.

BACKGROUND: Sleep disturbances after general surgery have been described. In this study, we assessed rapid eye movement (REM) sleep in patients undergoing knee replacement surgery using a regional anesthetic technique. METHODS: Ambulatory polysomnography (PSG) was performed on 3 nights: the night before surgery (PSG1), the first night after surgery (PSG2), and the fifth postoperative night (PSG3). Postoperative analgesia was maintained with peripheral nerve catheters for the first 3 days and with oral opioids thereafter. In addition, nonsteroidal antiinflammatory drugs were administered. Postoperative pain was monitored using a visual analog scale. RESULTS: PSG was performed in 12 patients, 6 men and 6 women, with a mean age of 61 (±12) years. REM sleep was reduced from PSG1 (median 16.4%) to PSG2 (median 6.3%; P = 0.02). The Hodges-Lehmann estimate for the median reduction is -7.8% (95% confidence interval -14.8% to -0.7%). During PSG3, significantly more REM sleep was detected (median 15.4%) compared with PSG2 (P = 0.01). The Hodges-Lehmann estimate for this median increase is 10.0% (95% confidence interval 1.7%-25.3%). CONCLUSION: Postoperative reduction of REM sleep also occurs after surgery and regional anesthesia.

Forced needle advancement during needle-nerve contact in a porcine model: histological outcome.

BACKGROUND: In this study, we determined whether needle advancement during needle-nerve contact (forced needle-nerve contact) is associated with a higher risk of nerve injury compared with needle-nerve contact without needle advancement (nonforced needle-nerve contact). METHODS: In 8 anesthetized pigs, the brachial plexus nerves underwent forced (0.15 Newton) or nonforced (0.0 Newton) needle-nerve contact without nerve penetration. The grade of nerve injury was histologically assessed using an objective score ranging from 0 (no injury) to 4 (severe injury). RESULTS: Sixty-nine nerves, including controls, were examined. Histology revealed a significant difference between forced and nonforced needle-nerve contact (median [interquartile range] 3 [2-4] vs 2 [1-2]; P = 0.004). Myelin damage and intraneural hematoma occurred only after forced needle-nerve contact. CONCLUSIONS: The severity of structural nerve injury after needle-nerve contact was directly related to force exposure via needle advancement.

Short term non-invasive ventilation post-surgery improves arterial blood-gases in obese subjects compared to supplemental oxygen delivery - a randomized controlled trial.

BACKGROUND: In the immediate postoperative period, obese patients are more likely to exhibit hypoxaemia due to atelectasis and impaired respiratory mechanics, changes which can be attenuated by non-invasive ventilation (NIV). The aim of the study was to evaluate the duration of any effects of early initiation of short term pressure support NIV vs. traditional oxygen delivery via venturi mask in obese patients during their stay in the PACU. METHODS: After ethics committee approval and informed consent, we prospectively studied 60 obese patients (BMI 30-45) undergoing minor peripheral surgery. Half were randomly assigned to receive short term NIV during their PACU stay, while the others received routine treatment (supplemental oxygen via venturi mask). Premedication, general anaesthesia and respiratory settings were standardized. We measured arterial oxygen saturation by pulse oximetry and blood gas analysis on air breathing. Inspiratory and expiratory lung function was measured preoperatively (baseline) and at 10 min, 1 h, 2 h, 6 h and 24 h after extubation, with the patient supine, in a 30 degrees head-up position. The two groups were compared using repeated-measure analysis of variance (ANOVA) and t-test analysis. Statistical significance was considered to be P < 0.05. RESULTS: There were no differences at the first assessment. During the PACU stay, pulmonary function in the NIV group was significantly better than in the controls (p < 0.0001). Blood gases and the alveolar to arterial oxygen partial pressure difference were also better (p < 0.03), but with the addition that overall improvements are of questionable clinical relevance. These effects persisted for at least 24 hours after surgery (p < 0.05). CONCLUSION: Early initiation of short term NIV during in the PACU promotes more rapid recovery of postoperative lung function and oxygenation in the obese. The effect lasted 24 hours after discontinuation of NIV. Patient selection is necessary in order to establish clinically relevant improvements. TRIAL REGISTRATION#: DRKS00000751; http://www.germanctr.de.

The influence of perioperative oxygen concentration on postoperative lung function in moderately obese adults.

BACKGROUND AND OBJECTIVE: Obesity aggravates the negative effects of general anaesthesia and surgery on the respiratory system, resulting in decreased functional residual capacity and expiratory reserve volume, and increased atelectasis and ventilation/perfusion (Va/Q) mismatch. High-inspired oxygen concentrations also promote atelectasis. This study compares the effects of perioperative inspired low-oxygen and high-oxygen concentrations on postoperative lung function and pulse oximetry values in moderately obese patients (BMI 25-35). METHODS: We prospectively studied 142 overweight patients, BMI 25-35, undergoing minor peripheral surgery; they were randomly allocated to receive either low-inspired or high-inspired oxygen concentrations during general anaesthesia. Premedication, general anaesthesia and respiratory patterns were standardized. Arterial oxygen saturation (pulse oximetry) was measured on air breathing. Inspiratory and expiratory lung functions were measured preoperatively (baseline) and at 10 min, 0.5, 2 and 24 h after extubation with the patient supine, in a 30 degrees head-up position. The two groups were compared using repeated-measure analysis of variance and t-test analysis. RESULTS: The low-inspired oxygen group had significantly better arterial saturation during the first 24 h (P < 0.01). Mid-expiratory flow 25 values indicating small airway collapse were significantly better in the low-oxygen group at all measurements (P < 0.05). CONCLUSION: We conclude that postoperative lung function and arterial saturation is better preserved by a low-oxygen strategy, although it is not clear whether this has clinical relevance for the prevention of postoperative pulmonary complications.