Impact of COVID-19 pandemic-induced surgical restrictions on operational performance: a case study at the University Hospital of Ulm.

INTRODUCTION: The operating room (OR) is a high-cost and high-revenue area in a hospital comprising extremely complex process steps to treat patients. The perioperative process quality can be optimized through an efficiency-oriented central OR management based on performance indices. However, during the COVID-19 pandemic with the corresponding OR restrictions, there was a significant nation- and worldwide decline in the performance, which may have a lasting impact. Therefore, we proposed the hypothesis that COVID-19 pandemic-related OR restrictions could reduce operative performance in the long term. METHODS: A retrospective, descriptive analysis of perioperative processing times was conducted exemplarily at the University Hospital Ulm using a pre-post design, examining the corresponding second quarters of 2019 to 2022. In total, n = 18,489 operations with n = 314,313 individual time intervals were analyzed. The statistical analyses included the Kruskal-Wallis test adjusted for multiple testing, and the significance level was set at p < 0.01. RESULTS: The results revealed not only a significant decrease in the case volume by 31% (2020) and 23% (2021) during the COVID-19 crisis years, but also significant time delays in various process steps; e.g. the median patient's OR occupancy time (column time) rose from 65 min (2019) to 87 min (2020) and remained elevated (72 min in 2021 and 74 min in 2022, respectively). Even in 2022, beyond the pandemic, the net anaesthesia time was permanently enhanced by 9 min per case. Furthermore, both, the incision-to-closure time and surgeon attachment time were each significantly prolonged by 7 additional minutes, and the time from the end of anaesthesia to the release of the next patient was extended by 4 min. Selected standardized index operations showed only a trend towards these changes, even with a decrease in the incision-to-closure time over time. CONCLUSION: Overall, long-term changes were found in essential perioperative process times even after retraction of the COVID-19 restrictions, indicating some processual "slow down" after the Covid-19-induced "shut down". Further analyses are needed to determine the appropriate targeted control measures to improve processing times and increase the process quality.

Reduced Rate of Inpatient Hospital Admissions in 18 German University Hospitals During the COVID-19 Lockdown.

The COVID-19 pandemic has caused strains on health systems worldwide disrupting routine hospital services for all non-COVID patients. Within this retrospective study, we analyzed inpatient hospital admissions across 18 German university hospitals during the 2020 lockdown period compared to 2018. Patients admitted to hospital between January 1 and May 31, 2020 and the corresponding periods in 2018 and 2019 were included in this study. Data derived from electronic health records were collected and analyzed using the data integration center infrastructure implemented in the university hospitals that are part of the four consortia funded by the German Medical Informatics Initiative. Admissions were grouped and counted by ICD 10 chapters and specific reasons for treatment at each site. Pooled aggregated data were centrally analyzed with descriptive statistics to compare absolute and relative differences between time periods of different years. The results illustrate how care process adoptions depended on the COVID-19 epidemiological situation and the criticality of the disease. Overall inpatient hospital admissions decreased by 35% in weeks 1 to 4 and by 30.3% in weeks 5 to 8 after the lockdown announcement compared to 2018. Even hospital admissions for critical care conditions such as malignant cancer treatments were reduced. We also noted a high reduction of emergency admissions such as myocardial infarction (38.7%), whereas the reduction in stroke admissions was smaller (19.6%). In contrast, we observed a considerable reduction in admissions for non-critical clinical situations, such as hysterectomies for benign tumors (78.8%) and hip replacements due to arthrosis (82.4%). In summary, our study shows that the university hospital admission rates in Germany were substantially reduced following the national COVID-19 lockdown. These included critical care or emergency conditions in which deferral is expected to impair clinical outcomes. Future studies are needed to delineate how appropriate medical care of critically ill patients can be maintained during a pandemic.

Laryngeal tube suction II or endotracheal intubation for laparoscopic radical prostatectomy in a head down position: A randomised controlled trial.

BACKGROUND: The laryngeal tube suction II (LTS II) is a supraglottic airway device (SAD) with a gastric drainage tube and enhanced seal properties as compared with other SADs. Therefore, its use has been proposed in situations with an elevated risk of aspiration. OBJECTIVES: To compare the safety and efficacy of airway management and controlled mechanical ventilation when using either an LTS II or an endotracheal tube for laparoscopic radical prostatectomy. DESIGN: Randomised, controlled, blinded and single-centre study. SETTING: Academic tertiary care centre in Leipzig from April 2014 to May 2015. PATIENTS: It was planned to include 100 patients but the study was stopped after 50 patients following an interim analysis. These 50 patients were randomised to either the LTS II group or the endotracheal tube group. All male patients aged more than 18 years for elective laparoscopic radical prostatectomy were eligible. Exclusion criteria included a BMI more than 30, American Society of Anesthesiologists class III or greater, a history of gastroesophageal reflux or other factors known to increase the risk of aspiration and a known difficult airway. INTERVENTIONS: All patients received general anaesthesia. Airway management was with either a LTS II or an endotracheal tube, according to the randomisation. MAIN OUTCOME MEASURES: The primary endpoint was successful insertion of the particular airway device during anaesthesia for laparoscopic radical prostatectomy. RESULTS: In 15 of the 28 patients randomised to LTS II, the device had to be removed and an endotracheal tube inserted, mainly because of an airway leak (n = 10) or swelling of the tongue (n = 3). Ventilation was successful in all patients (n = 22) randomised to endotracheal tube. Quality of ventilation was rated better in the endotracheal tube group. CONCLUSION: Our data suggest that LTS II should not be the preferred method of airway management in patients undergoing laparoscopic radical prostatectomy. TRIAL REGISTRATION: DRKS00008985 (German Clinical Trials Register).

Inhaled carbon monoxide protects time-dependently from loss of hypoxic pulmonary vasoconstriction in endotoxemic mice.

BACKGROUND: Inhaled carbon monoxide (CO) appears to have beneficial effects on endotoxemia-induced impairment of hypoxic pulmonary vasoconstriction (HPV). This study aims to specify correct timing of CO application, it's biochemical mechanisms and effects on inflammatory reactions. METHODS: Mice (C57BL/6; n = 86) received lipopolysaccharide (LPS, 30 mg/kg) intraperitoneally and subsequently breathed 50 ppm CO continuously during defined intervals of 3, 6, 12 or 18 h. Two control groups received saline intraperitoneally and additionally either air or CO, and one control group received LPS but breathed air only. In an isolated lung perfusion model vasoconstrictor response to hypoxia (FiO2 = 0.01) was quantified by measurements of pulmonary artery pressure. Pulmonary capillary pressure was estimated by double occlusion technique. Further, inflammatory plasma cytokines and lung tissue mRNA of nitric-oxide-synthase-2 (NOS-2) and heme oxygenase-1 (HO-1) were measured. RESULTS: HPV was impaired after LPS-challenge (p < 0.01). CO exposure restored HPV-responsiveness if administered continuously for full 18 h, for the first 6 h and if given in the interval between the 3(rd) and 6(th) hour after LPS-challenge (p < 0.05). Preserved HPV was attributable to recovered arterial resistance and associated with significant reduction in NOS-2 mRNA when compared to controls (p < 0.05). We found no effects on inflammatory plasma cytokines. CONCLUSION: Low-dose CO prevented LPS-induced impairment of HPV in a time-dependent manner, associated with a decreased NOS-2 expression.

Initial Experience With a Percutaneous Approach to Redo Mitral Valve Surgery: Management and Procedural Success.

OBJECTIVE: The purpose of the study was to report the anesthetic management and immediate procedural success in the initial 20 patients undergoing percutaneous transapical mitral valve replacement. DESIGN: Retrospective review of collected data. SETTING: University-affiliated heart center. PARTICIPANTS: Twenty patients with mitral regurgitation or stenosis due to a degenerated valve or ring in the mitral position. INTERVENTIONS: TEE-guided transapical mitral valve replacement under general anesthesia and early extubation by means of an established fast-track protocol. MEASUREMENTS AND MAIN METHODS: Twenty patients underwent transapical mitral valve replacement by a beating heart procedure, avoiding cardiopulmonary bypass. The valve was either deployed due to a previously implanted bioprosthetic valve (valve-in-valve group), which degenerated, or a ring (valve-in-ring group), which predominantly showed regurgitation. There was a significant increase in the mitral valve opening area in stenosed valve pathology from 1.3-1.9 sq. cm (p = 0.004), and an increase in ejection fraction from 40% to 45% (p = 0.52). In the valve-in-ring group, valve area increased from 2.0 sq. cm to 2.6 sq. cm (p = 0.21), with an increase in ejection fraction from 30% to 35% (p = 0.18). Eighteen patients underwent successful deployment of the valve. The anesthesia duration for the procedure lasted 185.5 ± 25.4 minutes. CONCLUSIONS: There was a significant increase in opening area of the valve and improvement in ejection fraction in this patient group. TEE and fluoroscopy-guided imaging is necessary for the procedure's success and is an evolving alternative treatment for high-risk mitral valve patients who would otherwise be considered inoperable for routine surgery using sternotomy.

Early prediction of survival after open surgical repair of ruptured abdominal aortic aneurysms.

BACKGROUND: Scoring models are widely established in the intensive care unit (ICU). However, the importance in patients with ruptured abdominal aortic aneurysm (RAAA) remains unclear. Our aim was to analyze scoring systems as predictors of survival in patients undergoing open surgical repair (OSR) for RAAA. METHODS: This is a retrospective study in critically ill patients in a surgical ICU at a university hospital. Sixty-eight patients with RAAA were treated between February 2005 and June 2013. Serial measurements of Sequential Organ Failure Assessment score (SOFA), Simplified Acute Physiology Score II (SAPS II) and Simplified Therapeutic Intervention Scoring System-28 (TISS-28) were evaluated with respect to in-hospital mortality. Eleven patients had to be excluded from this study because 6 underwent endovascular repair and 5 died before they could be admitted to the ICU. RESULTS: All patients underwent OSR. The initial, highest, and mean of SOFA and SAPS II scores correlated significant with in-hospital mortality. In contrast, TISS-28 was inferior and showed a smaller area under the receiver operating curve. The cut-off point for SOFA showed the best performance in terms of sensitivity and specificity. An initial SOFA score below 9 predicted an in-hospital mortality of 16.2% (95% CI, 4.3-28.1) and a score above 9 predicted an in-hospital mortality of 73.7% (95% CI, 53.8-93.5, p < 0.01). Trend analysis showed the largest effect on SAPS II. When the score increased or was unchanged within the first 48 h (score >45), the in-hospital mortality rate was 85.7% (95% CI, 67.4-100, p < 0.01) versus 31.6% (95% CI, 10.7-52.5, p = 0.01) when it decreased. On multiple regression analysis, only the mean of the SOFA score showed a significant predictive capacity with regards to mortality (odds ratio 1.77; 95% CI, 1.19-2.64; p < 0.01). CONCLUSION: SOFA and SAPS II scores were able to predict in-hospital mortality in RAAA within 48 h after OSR. According to cut-off points, an increase or decrease in SOFA and SAPS II scores improved sensitivity and specificity.

Respiratory complications after diode-laser-assisted tonsillotomy.

Children with certain risk factors, such as comorbidities or severe obstructive sleep apnea syndrome (OSAS) are known to require extended postoperative monitoring after adenotonsillectomy. However, there are no recommendations available for diode-laser-assisted tonsillotomy. A retrospective chart review of 96 children who underwent diode-laser-assisted tonsillotomy (07/2011-06/2013) was performed. Data for general and sleep apnea history, power of the applied diode-laser (λ = 940 nm), anesthesia parameters, the presence of postoperative respiratory complications and postoperative healing were evaluated. After initially uncomplicated diode-laser-assisted tonsillotomy, an adjustment of post-anesthesia care was necessary in 16 of 96 patients due to respiratory failure. Respiratory complications were more frequent in younger children (3.1 vs. 4.0 years, p = 0.049, 95 % CI -1.7952 to -0.0048) and in children who suffered from nocturnal apneas (OR = 5.00, p < 0.01, 95 % CI 1.4780-16.9152) or who suffered from relevant comorbidities (OR = 4.84, p < 0.01, 95 % CI 1.5202-15.4091). Moreover, a diode-laser power higher than 13 W could be identified as a risk factor for the occurrence of a postoperative oropharyngeal edema (OR = 3.45, p < 0.01, 95 % CI 1.3924-8.5602). Postoperative respiratory complications should not be underestimated in children with sleep-disordered breathing (SDB). Therefore, children with SDB, children with comorbidities or children younger than 3 years should be considered "at risk" and children with confirmed moderate to severe OSAS should be referred to a PICU following diode-laser-assisted tonsillotomy. We recommend a reduced diode-laser power (<13 W) to reduce oropharyngeal edema.

Obesity in anesthesia and intensive care.

Obesity is a global epidemic increasingly affecting management of anesthesia as well as intensive care medicine. Possible improvements in therapy require consideration of the specific pathophysiology of the obese, their concomitant diseases, and the complications associated with morbid obesity. Systematic assessment of perioperative risk factors is essential for an appropriate management. Paradoxically, overweight and moderately obese patients undergoing surgery have a lower risk when compared to patients with normal weight. The highest mortality and morbidity rates in this setting are reported for underweight and morbidly obese patients. The better chance of survival when compared to normal-weight individuals in the perioperative setting has been described the obesity paradox. In particular, the commitment of all involved physicians to improve all aspects of care will reduce the perioperative risk in obese patients. Physiological and pharmacological characteristics of the obese should also be considered. Furthermore, adequate technical equipment and practical skills of all members of the anesthesia team significantly contribute to risk reduction and therapeutic success in obese patients.

Cerebrospinal fluid melanin-concentrating hormone (MCH) and hypocretin-1 (HCRT-1, orexin-A) in Alzheimer's disease.

Ancillary to decline in cognitive abilities, patients with Alzheimer's disease (AD) frequently suffer from behavioural and psychological symptoms of dementia (BPSD). Hypothalamic polypeptides such as melanin-concentrating hormone (MCH) and hypocretin-1 (HCRT-1, orexin-A) are promoters of sleep-wake regulation and energy homeostasis and are found to impact on cognitive performance. To investigate the role of MCH and HCRT-1 in AD, cerebrospinal fluid (CSF) levels were measured in 33 patients with AD and 33 healthy subjects (HS) using a fluorescence immunoassay (FIA). A significant main effect of diagnosis (F(1,62) = 8.490, p<0.01) on MCH levels was found between AD (93.76±13.47 pg/mL) and HS (84.65±11.40 pg/mL). MCH correlated with T-tau (r = 0.47; p<0.01) and P-tau (r = 0.404; p<0.05) in the AD but not in the HS. CSF-MCH correlated negatively with MMSE scores in the AD (r = -0.362, p<0.05) and was increased in more severely affected patients (MMSE≤20) compared to HS (p<0.001) and BPSD-positive patients compared to HS (p<0.05). In CSF-HCRT-1, a significant main effect of sex (F(1,31) = 4.400, p<0.05) with elevated levels in females (90.93±17.37 pg/mL vs. 82.73±15.39 pg/mL) was found whereas diagnosis and the sex*diagnosis interaction were not significant. Elevated levels of MCH in patients suffering from AD and correlation with Tau and severity of cognitive impairment point towards an impact of MCH in AD. Gender differences of CSF-HCRT-1 controversially portend a previously reported gender dependence of HCRT-1-regulation. Histochemical and actigraphic explorations are warranted to further elucidate alterations of hypothalamic transmitter regulation in AD.

Is real time 3D transesophageal echocardiography a feasible approach to detect coronary ostium during transapical aortic valve implantation?

OBJECTIVE: Transapical aortic valve implantation (TAVI) may lead to obstruction of coronary arteries during deployment. To prevent this, it is essential to determine the distance of the coronary ostium to the aortic annulus prior to valve placement. Multidetector computed tomography (MDCT) commonly is used to determine these measurements, but even marginal exposure to contrast agents can result in acute kidney injury in this high-risk group of multi-morbid patients. The aim of the study was to determine the feasibility of real-time 3D transesophageal echocardiography (RT 3D TEE) as the first-choice technique for noninvasive evaluation of the coronary ostium during TAVI. DESIGN: Retrospective study. SETTING: University hospital. INTERVENTIONS: Fifty patients underwent MDCT the evening before surgery. RT 3D TEE was performed intraoperatively before valve deployment. The dataset from both of these examinations was digitally stored and evaluated. MDCT was performed in nonanesthetized patients; however, in the RT 3D TEE group, general anesthesia was established. MEASUREMENTS AND MAIN RESULTS: The distances from the right coronary artery and the left coronary artery ostium were measured retrospectively. Bland-Altman Plots and linear regression analysis showed excellent correlation between the 2 methodologies; intraobserver and interobserver variance were calculated using analysis of variance. Krippendorff's α indicated excellent agreement between the 2 observers (0.96 and 0.98) as well as between RT 3D TEE and MDCT (0.97 and 0.98). CONCLUSIONS: The observations showed that RT 3D TEE reliably can measure the coronary ostium distance from the aortic annulus. It is feasible and an alternative method for evaluating these measurements and thereby preventing contrast exposure during MDCT, which may jeopardize the safety of patients with pre-existing renal disease.

Bedside estimation of nonaerated lung tissue using blood gas analysis.

OBJECTIVES: Studies correlating the arterial partial pressure of oxygen to the fraction of nonaerated lung assessed by CT shunt yielded inconsistent results. We systematically analyzed this relationship and scrutinized key methodological factors that may compromise it. We hypothesized that both physiological shunt and the ratio between PaO2 and the fraction of inspired oxygen enable estimation of CT shunt at the bedside. DESIGN: : Prospective observational clinical and laboratory animal investigations. SETTING: ICUs (University Hospital Leipzig, Germany) and Experimental Pulmonology Laboratory (University of São Paulo, Brazil). PATIENTS, SUBJECTS AND INTERVENTIONS: Whole-lung CT and arterial blood gases were acquired simultaneously in 77 patients mechanically ventilated with pure oxygen. A subgroup of 28 patients was submitted to different Fio2. We also studied 19 patients who underwent repeat CT. Furthermore we studied ten pigs with acute lung injury at multiple airway pressures, as well as a theoretical model relating PaO2 and physiological shunt. We logarithmically transformed the PaO2/Fio2 to change this nonlinear relationship into a linear regression problem. MEASUREMENTS AND MAIN RESULTS: We observed strong linear correlations between Riley's approximation of physiological shunt and CT shunt (R = 0.84) and between logarithmically transformed PaO2/Fio2 and CT shunt (R = 0.86), allowing us to construct a look-up table with prediction intervals. Strong linear correlations were also demonstrated within-patients (R = 0.95). Correlations were significantly improved by the following methodological issues: measurement of PaO2/Fio2 during pure oxygen ventilation, use of logarithmically transformed PaO2/Fio2 instead of the "raw" PaO2/Fio2, quantification of nonaerated lung as percentage of total lung mass and definition of nonaerated lung by the [-200 to +100] Hounsfield Units interval, which includes shunting units within less opacified lung regions. CONCLUSION: During pure oxygen ventilation, logarithmically transformed PaO2/Fio2 allows estimation of CT shunt and its changes in patients during systemic inflammation. Relevant intrapulmonary shunting seems to occur in lung regions with CT numbers between [-200 and +100] Hounsfield Units.

Intrathecal morphine is superior to intravenous PCA in patients undergoing minimally invasive cardiac surgery.

Aim of our study was to evaluate the beneficial effect of low dose intrathecal morphine on postoperative analgesia, over the use of intravenous patient controlled anesthesia (PCA), in patients undergoing fast track anesthesia during minimally invasive cardiac surgical procedures. A randomized controlled trial was undertaken after approval from local ethical committee. Written informed consent was obtained from 61 patients receiving mitral or tricuspid or both surgical valve repair in minimal invasive technique. Patients were assigned randomly to 2 groups. Group 1 received general anesthesia and intravenous patient controlled analgesia (PCA) pump with Piritramide (GA group). Group 2 received a single shot of intrathecal morphine (1.5 µg/kg body weight) prior to the administration of general anesthesia (ITM group). Site of puncture was confined to lumbar (L1-2 or L2-3) intrathecal space. The amount of intravenous piritramide used in post anesthesia care unit (PACU) and the first postoperative day was defined as primary end point. Secondary end points included: time for tracheal extubation, pain and sedation scores in PACU upto third postoperative day. For statistical analysis Mann-Whitney-U Test and Fishers exact test (SPSS) were used. We found that the demand for intravenous opioids in PACU was significantly reduced in ITM group (P <0.001). Pain scores were significantly decreased in ITM group until second postoperative day (P <0.01). There was no time delay for tracheal extubation in ITM group, and sedation scores did not differ in either group. We conclude that low dose single shot intrathecal morphine provides adequate postoperative analgesia, reduces the intravenous opioid consumption during the early postoperative period and does not defer early extubation.

Effects of Music Listening on Cortisol Levels and Propofol Consumption during Spinal Anesthesia.

BACKGROUND: This study explores effects of instrumental music on the hormonal system (as indicated by serum cortisol and adrenocorticotropic hormone), the immune system (as indicated by immunoglobulin A) and sedative drug requirements during surgery (elective total hip joint replacement under spinal anesthesia with light sedation). This is the first study investigating this issue with a double-blind design using instrumental music. METHODOLOGY/PRINCIPAL FINDINGS: Patients (n = 40) were randomly assigned either to a music group (listening to instrumental music), or to a control group (listening to a non-musical placebo stimulus). Both groups listened to the auditory stimulus about 2 h before, and during the entire intra-operative period (during the intra-operative light sedation, subjects were able to respond lethargically to verbal commands). Results indicate that, during surgery, patients of the music group had a lower propofol consumption, and lower cortisol levels, compared to the control group. CONCLUSION/SIGNIFICANCE: Our data show that listening to music during surgery under regional anesthesia has effects on cortisol levels (reflecting stress-reducing effects) and reduces sedative requirements to reach light sedation.

Real-time three-dimensional echocardiographic assessment of mitral valve: Is it really superior to 2D transesophageal echocardiography?

Aim of our study was to investigate the feasibility of use and possible additional value of real-time 3D transesophageal echocardiography (RT-3D-TEE) compared to conventional 2D-TEE in patients undergoing elective mitral valve repair. After ethical committee approval, patients were included in this prospective study. After induction of anesthesia, a comprehensive 2D-TEE examination was performed, followed with RT-3D-TEE. The intraoperative surgical finding was used as the gold standard for segmental analysis. Only such segments which were surgically corrected either by resection or insertion of artificial chords were judged pathologic. A total of 50 patients were included in this study; usable data were available from 42 of these patients . Based on the Carpentier classification, the pathology found was type I in 2 (5%) patients, type II in 39 (93%) patients and type IIIb in 1 (2%) patient. We found that 3D imaging of complex mitral disease involving multiple segments, when compared to 2D-TEE did not show any statistically significant difference.RT-3D-TEE did not show any major advantage when compared to conventional 2D-TEE for assessing mitral valve pathology, although further study in a larger population is required to establish the validity of this study.

Blood lactate and pyruvate levels in the perioperative period of liver resection with Pringle maneuver.

INTRODUCTION: Bleeding during liver surgery is often routinely controlled by the Pringle maneuver consisting in the temporary clamping of hepatic artery, portal vein, and bile duct. This study aimed at investigating a possible influence of the Pringle maneuver on tissue hypoxia during liver resection. METHODS: Twenty-five consecutive patients undergoing elective liver resection were prospectively randomized either to be treated with the Pringle maneuver (Pringle group, n = 14) or without clamping (Controls, n = 11). Blood lactate levels, pyruvate levels, and hepatic vein oxygen saturation were monitored perioperatively. RESULTS: Patients were comparable with respect to resection time, intraoperative blood loss, and duration of surgery. The Pringle maneuver induced a significant increase in arterial lactate levels during liver resection when compared to Controls (2.6 +/- 0.3 vs 1.8 +/- 0.2 mmol/l; p < 0.05). Further, the Pringle maneuver significantly increased hepatic venous lactate (3.3 +/- 0.3 vs 1.6 +/- 0.3 mmol/l; p < 0.05) and lactate/pyruvate ratio in hepatic venous blood (43 +/- 8 vs 21 +/- 5; p < 0.05) during surgery. This was paralleled by a temporal decrease in hepatic venous oxygen saturation in the Pringle group (61 +/- 4 vs 73 +/- 4%; p < 0.05). CONCLUSION: Our findings demonstrate that liver metabolism and tissue oxygenation were markedly affected by occlusion of the liver hilus. Restricting the use of the Pringle maneuver to cases with severe bleeding might therefore be beneficial in patients undergoing liver resection.

Echocardiographic identification of iatrogenic injury of the circumflex artery during minimally invasive mitral valve repair.

BACKGROUND: Injury to the circumflex artery after mitral valve (MV) repair or replacement is a recognized complication of this procedure. We designed an echocardiographic method to visualize the course and flow of the circumflex artery, to detect iatrogenic injury to this structure intraoperatively, as well as to predict the coronary dominance pattern in MV surgery patients. METHODS: After Ethics Committee approval, a prospective study was undertaken in 110 patients undergoing minimal invasive MV repair. Intraoperative transesophageal echocardiography was used to visualize the circumflex artery using a combination of B-mode imaging and color Doppler with different Nyquist limits. The course of the circumflex artery and the coronary sinus and their corresponding diameters were documented at the proximal and distal ends of both vessels. Preoperative angiographic data were used to determine the coronary dominance type. RESULTS: The course of the circumflex artery could be detected proximally in 109 patients (99%), to the point of intersection with the coronary sinus in 99 patients (90%), and distal to this intersection in 95 patients (86%) using our technique. Three patients had evidence of iatrogenic aliasing (circumflex stenosis) or "no flow" (circumflex occlusion) on transesophageal echocardiography examination after repair and therefore underwent surgical or percutaneous correction. All 3 of these patients had an uncomplicated postoperative course thereafter with no evidence of perioperative myocardial infarction. All remaining patients with normal circumflex examinations after repair did not show any clinical evidence of myocardial infarction or unstable hemodynamics postoperatively. The 95% confidence interval for the diameter of the proximal circumflex artery was 4.5 mm to 5.6 mm for the left dominant type patients and 3.8 mm to 4.2 mm for the right dominant and balanced type patients (p = 0.01). CONCLUSIONS: The early recognition of iatrogenic injury of the circumflex artery is feasible with intraoperative transesophageal echocardiography examination, and may lead to treatment before extensive myocardial infarction occurs. We suggest that visualization of the circumflex artery with our technique should be performed more frequently in patients undergoing MV surgery.

High-frequency jet ventilation as an alternative method compared to conventional one-lung ventilation using double-lumen tubes during minimally invasive coronary artery bypass graft surgery.

OBJECTIVE: To optimize the conditions for the surgeon during minimally invasive direct coronary artery bypass (MIDCAB) and totally endoscopic coronary artery bypass (TECAB) procedures, one-lung ventilation (OLV) is required using double-lumen tubes (DLT). This prospective study was designed to compare high-frequency jet ventilation (HFJV) of both lungs with the conventional method of OLV via DLT. DESIGN: Prospective, randomized, clinical study. SETTING: University-affiliated heart center. PARTICIPANTS: Forty patients with coronary artery disease and scheduled for elective MIDCAB or TECAB procedures were equally randomized into a DLT and an HFJV group. INTERVENTIONS: In the DLT group, OLV of the right lung was performed throughout the surgical procedure. In the HFJV group, patients received a conventional single-lumen endotracheal tube and both lungs were ventilated using HFJV. MEASUREMENTS: Hemodynamic, oxygenation and ventilation parameters were measured at the beginning of the operation, then 5, 15, 30, and 60 minutes after OLV/HFJV, as well as immediately before transfer to the ICU. MAIN RESULTS: Regarding the view of the surgical field, surgeons' comfort did not differ between methods. The intraoperative PaO(2) was significantly higher in the HFJV group compared with the DLT group at 5 (336.8 +/- 123.3 v 228.6 +/- 124.0; p = 0.009) and 15 minutes (301.7 +/- 133.9 v 192.6 +/- 92.8; p = 0.012). The PaCO(2) was significantly higher in the HFJV group after 5 minutes and persisted through 60 minutes of ventilation. The peak inspiratory pressure was significantly lower during HFJV (10.0 +/- 2.8 mbar v 32.1 +/- 5.9 mbar). CONCLUSIONS: HFJV in MIDCAB or TECAB procedures appears to be a feasible alternative to OLV using a DLT, although study in a larger population is required.

Inflammatory response is no different in children randomized to laparoscopic or open appendectomy.

BACKGROUND: Previous studies suggest that the inflammatory response after laparoscopic appendectomy is less pronounced than after open surgery. OBJECTIVE: To compare the clinical course and serum levels of a variety of immunoinflammatory markers in children randomized to either laparoscopic or open appendectomy for nonperforated appendicitis. MATERIALS AND METHODS: Children with the diagnosis of appendicitis were randomized to either laparoscopicor open appendectomy after informed consent for participation in the study was obtained. Body temperature,leukocyte count, hematocrit and serum levels of the inflammatory markers c-reactive protein, interleukin (IL)-6, tumor necrosis factor (TNF)-, sTNF-R, IL-1Ra, sIL-2R, and IL-8 were determined at six different times: Before anesthesia induction, at skin incision, after wound closure, as well as 12, 24, and 72 hours postoperatively.Length of in-hospital stay was assessed as well. Parameters with normal distribution were compared by Student test for independent samples, all others were compared by the Mann-Whitney U test. P 0.05 was considered statistically significant. RESULTS: A total of 47 patients with appendicitis were recruited and randomized. Retrospectively, four patients in the open group and three in the laparoscopic group were excluded from the analysis because perforated appendicitis was described on their histopathologic report, leaving an equal number of patients in each study cohort(n = 20 each). There was no significant difference in demographic variables including age, body weight,and duration of symptoms. There were also no significant differences in body temperature, hematocrit, leukocytecount, or any of the inflammatory markers mentioned above. Average postoperative length of stay without any complications was 6.2 +/-2.5 days in the open group and 4.3 +/- 1.1 days in the laparoscopic group (P 0.01). CONCLUSION: We found no differences in inflammatory parameters after open and laparoscopic appendectomy for nonperforated appendicitis. However, surgeons send their laparoscopically operated patients home earlier.

[Principles and risks of electrosurgery]. / Elektrochirurgie--Grundlagen und Risiken.

Electrosurgical instruments are routinely used in many applications by the surgeon. In principle, high-frequency electrical currents are used by passing trough tissue for cutting and coagulation. The heat generated by the electrosurgical unit is proportional to the resistance and diameter of the tissue. There are two commonly used electrosurgical modalities: monopolar and bipolar. Since negative side-effects of electrosurgery are possible (e.g. burn, interaction with other electric devices) a proper knowledge of all staff involved in electrosurgery is warranted. In the context of a safe perioperative patient management the anesthesiologist should know basic principles of high-frequency surgery as well. This article describes the main aspects of electrosurgery for anesthesiologists.