ABSTRACT: HintergrundDie Implementierung neuer Anästhetika kann sich laut zahlreicher pharmakoökonomischer Studien günstig auf die Ausleitungszeiten
und damit auf die Leistungsfähigkeit einer Anästhesieabteilung auswirken. Aufgrund der artifiziellen Studienprotokolle ist
unklar, ob sich diese Ergebnisse auch auf den klinischen Routinebetrieb deutscher Krankenhäuser übertragen lassen.
MethodeAn 10 deutschen Krankenhäusern, die bis zum Studienbeginn ausschließlich Sevofluran eingesetzt hatten, wurden die Auswirkungen
einer Ad-hoc-Einführung von Desfluran auf die Ausleitungszeiten (primäres Zielkriterium) und das klinische Outcome [erhoben
mit dem Quality of Recovery Score- (QoR-)40 als sekundärer Zielgröße] elektiver chirurgischer Patienten untersucht. Nach einer
kurzen Schulung wurde die Allgemeinanästhesie randomisiert und untersuchergeblindet entweder mit Sevofluran (n=186) oder Desfluran
(n=176) aufrechterhalten. Das gesamte sonstige Narkoseregime wurde wie an den einzelnen Kliniken üblich beibehalten.
ErgebnisseIn allen Parametern der unmittelbaren postoperativen Erholung (u.a. Zeit bis Extubation, Nennen des Namens, Aufwachraumzeit)
ergaben sich für mit Desfluran behandelte Patienten signifikant bessere Werte. Bei einer Nachbefragung 24h nach der Operation
mit dem QoR-40-Fragebogen zeigten sich dagegen keine Gruppenunterschiede mehr.
DiskussionDie Ad-hoc-Einführung einer neuen anästhesiologischen Technik oder neuen Substanz (hier Desfluran) kann sofort nach ihrer
Implementierung in einer Anästhesieabteilung die Leistungsfähigkeit (hier: Ausleitungszeiten und Verweildauer im Aufwachraum)
BackgroundAccording to numerous pharmacoeconomic studies new anaesthesia techniques can improve recovery times and thus can have a positive
economic impact on patient turnover. However, artificial study protocols do not always match real world situations and thus
the practical impact of such studies remains unclear.
Material and methodsAt 10 hospitals exclusively using sevoflurane as a volatile anaesthetic, the ad hoc implementation of desflurane was studied
with respect to post-anaesthetic recovery times (primary endpoint) and postoperative outcome measured by the Quality of Recovery
Score- (QoR-)40, on the first postoperative day was investigated. Randomization of patients undergoing elective surgical procedures
under general anaesthesia with sevoflurane (n=186) or desflurane (n=176) was started immediately after a period of a few days
afterintroducing the new drug to all participants. Except for the volatile anaesthetic the anaesthetic procedure was performed
according to local standing operating procedures.
ResultsAll parameters indicating the immediate postanaesthetic recovery were superior in the patients receiving desflurane (mean±SD).
Time to extubation was accelerated from 8.7±9.7 to 6.2±6.8min. Times to recalling name and date of birth were accelerated
by 2.6 and 3.8min, respectively. Transferring the patients from the operating theatre to the post-anaesthetic recovery unit
was 17.3±11.5min after sevoflurane and 13.7±7.8min after anaesthesia with desflurane. Eligibility for discharge according
to a modified Aldrete score (White and Song 1999) was reached after 103±98 and 79±76min, respectively. The postoperative
recovery (QoR 40 questionnaire) did not differ 24h later.
DiscussionThe implementation of a new drug (here: desflurane to substitute sevoflurane) can improve speed of recovery immediately after
termination of anaesthesia even after a very short period of introducing the new technique but has no positive long term effects.
Thus, the results of this trial performed under a real world scenario (health service research) without tight standardization
by an artificial study protocol supports the results originating from randomized controlled clinical trials.
KeywordsDesflurane–Sevoflurane–Health service research–Postoperative recovery–Economy
Der Anaesthesist 05/2012; 60(1):39-48. · 0.99 Impact Factor
ABSTRACT: Studies conducted shortly after the implementation of pulse oximetry (PO) into clinical practice 20-25 years ago revealed that many patients breathing room air during transfer from the operating room (OR) to the post-anesthesia care unit (PACU) directly after general anesthesia (GA) had a peripheral oxygen saturation (S(p)O(2)) below 90%. Moreover, it was shown that the detection of hypoxemia by clinical criteria is extremely unreliable. Meanwhile, the use of PO has become part of the obligatory standard monitoring during GA in Germany and many other countries. Likewise, the use of PO is standard care in the PACU although there are no official recommendations. However, for the time period in between, i.e. immediately after GA during transportation of patients from the OR to the PACU, monitoring of the S(p)O(2) in patients breathing room air is neither obligatory in Germany nor are there any official recommendations or guidelines in this respect. Given the introduction of shorter acting anesthetic agents within the last 25 years, the main goal of this study was to explore whether the incidence of hypoxemia in the immediate period after GA is still so high. Additional aims of this study were to examine whether the detection of hypoxemia based on clinical criteria can be confirmed to be very unreliable, what the risk factors for hypoxemia following GA are and how common it is in Germany to transport patients from the OR to the PACU without PO and supplemental oxygen.
In a prospective observational study 970 patients who underwent a broad spectrum of elective surgery under GA in a university hospital setting were included. The S(p)O(2) was measured at the end of the transfer from the OR to the PACU immediately after the anesthetist who had taken care of the patient during the operation had estimated the S(p)O(2). The association between biometric, surgical and anesthesiological variables on the one hand and hypoxemia as well as a decrease of S(p)O(2) on the other hand were studied using multivariate methods. Finally, a survey including all university hospitals was carried out to find out about the use of PO and oxygen during patient transfer from the OR to the PACU.
Of the 959 patients who were eligible for analysis 17% had a S(p)O(2) < 90% and 6.6% a S(p)O(2) < 85%. Hypoxemia was not recognized in 82% of the patients in whom an assessment based on clinical grounds was carried out. Variables with an independent influence on hypoxemia and decrease of S(p)O(2) were as follows: saturation before induction of GA, body mass index, age, American Society of Anesthesiologists (ASA) physical status, difference between maximum and minimum inspiratory pressure, mode of ventilation, the choice of opioid and muscle relaxant as well as the use of nitrous oxide. Patient-dependent risk factors had the strongest impact on hypoxemia. In about 80% of the university hospitals neither PO nor supplemental oxygen is used during transportation of the patient from the OR to the PACU.
The use of opioids and relaxants with short duration of action may have favorable effects on preventing hypoxemia and decreases of S(p)O(2). These measures will, however, not be sufficient to solve this problem because the highest risk factors for hypoxemia are patient-related. Despite knowing risk factors for oxygen desaturation, it is currently not possible to reliably predict which patients will become hypoxemic or have a decrease of S(p)O(2). Therefore, transportation of patients breathing room air from the OR to the PACU directly after GA without use of PO or supplemental oxygen seems to be questionable in terms of patient safety.
Der Anaesthesist 04/2012; 61(4):299-309. · 0.99 Impact Factor
ABSTRACT: Pressure infusion devices are used in clinical practice to apply large volumes of fluid over a short period of time. Although air infusion is a major complication, they have limited capability to detect and remove air during pressure infusion. In this investigation, we tested the air elimination capabilities of the Fluido(®) (The Surgical Company), Level 1(®) (Level 1 Technologies Inc.) and Ranger(®) (Augustine Medical GmbH) pressure infusion devices. Measurements were undertaken with a crystalloid solution during an infusion flow of 100, 200, 400 and 800 ml.min(-1). Four different volumes of air (25, 50, 100 and 200 ml) were injected as boluses in one experimental setting, or infused continuously over the time needed to perfuse 2 l saline in the other setting. The perfusion fluid was collected in an airtight infusion bag and the amount of air obtained in the bag was measured. The delivered air volume was negligible and would not cause any significant air embolism in all experiments. In our experimental setting, we found, during high flow, an increased amount of uneliminated air in all used devices compared with lower perfusion flows. All tested devices had a good air elimination capability. The use of ultrasonic air detection coupled with an automatic shutoff is a significant safety improvement and can reliably prevent accidental air embolism at rapid flows.
Anaesthesia 11/2011; 66(11):1031-4. · 2.96 Impact Factor
ABSTRACT: Preoperative stress influences perioperative complications. Their severity is influenced by advanced information and previous experience. This study evaluates the emotional effects of these factors.
In a prospective observational study we documented existing anaesthesiological pre-information and previous experience of 461 patients (255 w/206 m) individually. In addition, we recorded the affective emotional condition of each patient before and after the premedication visit via a visual analogue scale (VAS) and a test of current stress (KAB).
248 patients had previous anaesthesiological pre-information. Of those 61 were of a negative nature. These patients showed a significantly higher level of stress and anxiety compared to those with positive information. 41 of 388 patients reported bad experiences with increased anxiety and stress. The premedication visits caused a significant attenuation of the overall stress level in patients with negative experience/information.
During the individual premedication visit, patients should be asked directly about negative pre-information and perioperative experience. Thus the conversation can be customised to the individual stress factors and show empathy as well. Independent of any medical intervention, this approach can be an effective contribution to stress reduction.
Zeitschrift für Geburtshilfe und Neonatologie 02/2011; 215(1):29-34.
ABSTRACT: Due to a variety of reasons (e.g. increase in outpatient surgery and legal restrictions related to working hours) it has become increasingly more difficult to have the pre-anesthesia visit and the anesthesia carried out by the same anesthetist. In the light of these organizational changes as well as increasing economical pressure it has become common practice to implement pre-anesthesia assessment clinics. It is unclear, however, if these changes in anesthetic patient care respect patient needs.
By means of a survey using the willingness to pay method, the relative significance of five quality aspects (location of pre-anesthesia visit, waiting time, patient-physician relationship, use of multimedia and ambience) were studied. Participation during a 12-month study period was on a voluntary basis.
Of the 1,058 questionnaires, 1,014 were eligible for analysis. A pre-anesthesia visit performed by the anesthetist who would deliver anesthesia was the most important aspect for almost two thirds (624 out of 1,014) of the patients with on average more than one third of the money available spent on this item. Waiting time was the second most important factor with about one third of the patients rating this item as the most relevant factor and on average approximately one quarter of the total money available spent on it. Location of the pre-anesthesia visit, use of multimedia and ambience were considered least important. The order of these preferences was regardless of age and gender of subjects. However, there was a trend to age and gender-specific differences concerning the amount of money spent on these five items. For instance, with increasing age, patient-physician relationship and location of the pre-anesthesia visit become more important.
These results suggest that the integration of a pre-anesthesia assessment clinic in anesthetic patient care is not favorable from the patients' point of view because getting to know the anesthetist who will deliver anesthesia is of paramount importance to most patients. In cases where a pre-anesthetic assessment clinic is indispensable, other measures to build up confidence compensating for the lack of personal patient-physician relationship should be developed. In this respect, the promotion of a corporate identity of the whole anesthesia department may be beneficial. Furthermore, keeping the waiting time as short as possible should be a high priority as this item was rated the second most important factor.
Der Anaesthesist 12/2010; 60(5):414-20. · 0.99 Impact Factor
ABSTRACT: According to numerous pharmacoeconomic studies new anaesthesia techniques can improve recovery times and thus can have a positive economic impact on patient turnover. However, artificial study protocols do not always match real world situations and thus the practical impact of such studies remains unclear.
At 10 hospitals exclusively using sevoflurane as a volatile anaesthetic, the ad hoc implementation of desflurane was studied with respect to post-anaesthetic recovery times (primary endpoint) and postoperative outcome measured by the Quality of Recovery Score- (QoR-)40, on the first postoperative day was investigated. Randomization of patients undergoing elective surgical procedures under general anaesthesia with sevoflurane (n=186) or desflurane (n=176) was started immediately after a period of a few days after introducing the new drug to all participants. Except for the volatile anaesthetic the anaesthetic procedure was performed according to local standing operating procedures.
All parameters indicating the immediate postanaesthetic recovery were superior in the patients receiving desflurane (mean±SD). Time to extubation was accelerated from 8.7±9.7 to 6.2±6.8 min. Times to recalling name and date of birth were accelerated by 2.6 and 3.8 min, respectively. Transferring the patients from the operating theatre to the post-anaesthetic recovery unit was 17.3±11.5 min after sevoflurane and 13.7±7.8 min after anaesthesia with desflurane. Eligibility for discharge according to a modified Aldrete score (White and Song 1999) was reached after 103±98 and 79±76 min, respectively. The postoperative recovery (QoR 40 questionnaire) did not differ 24 h later.
The implementation of a new drug (here: desflurane to substitute sevoflurane) can improve speed of recovery immediately after termination of anaesthesia even after a very short period of introducing the new technique but has no positive long term effects. Thus, the results of this trial performed under a real world scenario (health service research) without tight standardization by an artificial study protocol supports the results originating from randomized controlled clinical trials.
Der Anaesthesist 11/2010; 60(1):39-48. · 0.99 Impact Factor
ABSTRACT: In this study, we evaluated the influence of propofol versus desflurane anesthesia in overweight patients on postoperative lung function and pulse oximetry values.
We prospectively studied 134 patients with body mass indices of 25 to 35 kg/m(2) undergoing minor peripheral surgery lasting 40 to 120 minutes. Patients were randomly assigned to receive propofol (total IV anesthesia) or desflurane anesthesia via a tracheal tube targeting bispectral index values of 40 to 60. Premedication, adjuvant drug usage, and ventilation were standardized. We measured oxyhemoglobin saturation and lung function preoperatively (baseline), and at 10 minutes, 0.5 hour, 2 hours, and 24 hours after tracheal extubation. All values were measured with the patient supine, in a 30° head-up position. Changes from preoperative baseline values were first analyzed for the impact of body mass index and type of anesthesia using univariate methods, followed by linear regression and multivariate analysis of variance.
Within the first 2 hours after surgery, the propofol group displayed lower oxyhemoglobin saturation (at 2 hours, mean ± SD, 93.8% ± 2.0% vs 94.6% ± 2.1%; P < 0.007) and lung function (forced vital capacity, forced expiratory volume exhaled in 1 second [FEV(1)], peak expiratory flow, midexpiratory flow [MEF], forced inspiratory vital capacity, and peak inspiratory flow; between 11% and 20% larger reduction from baseline in the propofol group, all P < 0.001) compared with the desflurane group. Even 24 hours after surgery, FEV(1), peak expiratory flow, MEF, forced inspiratory vital capacity, and peak inspiratory flow were reduced more in the propofol group (all P < 0.01). At 2 hours after extubation, increasing obesity was associated with decreasing FEV(1) and MEF in patients anesthetized with propofol but not desflurane (P < 0.01).
We conclude that, for superficial surgical procedures of up to 120 minutes, maintenance of anesthesia with propofol impairs early postoperative lung function and pulse oximetry values more than with desflurane. Furthermore, increasing obesity decreases pulmonary function at 2 hours after propofol anesthesia but not after desflurane anesthesia.
Anesthesia and analgesia 10/2010; 113(1):63-9. · 3.08 Impact Factor
ABSTRACT: Obesity impairs peri-operative lung function. To evaluate the impact of pressure support ventilation vs pressure controlled ventilation in moderately obese adults upon early postoperative lung function, we randomly assigned 68 moderately obese patients (body mass index 25-35 kg x m(-2)) undergoing minor surgery to receive intra-operative ventilation either with pressure support or pressure controlled ventilation. We performed intra-operative blood gas analysis and measured pulse oximetry saturation, spirometry values at pre-operative assessment (baseline) and at 10 min, 30 min, 2 h and 24 h after extubation. The intra-operative oxygenation index (arterial partial pressure of oxygen/fraction of inspired oxygen) in the pressure support ventilation group was significantly improved over time (p < 0.0001). Postoperatively, the pressure support ventilation group also had better lung function and oxygenation values than did the pressure controlled ventilation group (p < 0.005). We conclude that pressure support ventilation better maintains lung function than pressure controlled ventilation in moderately overweight patients scheduled for minor surgery.
Anaesthesia 12/2009; 65(2):124-9. · 2.96 Impact Factor
ABSTRACT: Sleep-related breathing disorders have been associated with increased perioperative morbidity and mortality. The respective patients are at risk during two independent periods. Besides an early period, characterised by the influence of anaesthetics, patients are at risk also during a late period, which is characterised by nocturnal desaturation and disturbances of the cardiovascular system, caused by interference with the sleep architecture, especially of the REM sleep. To assure a safe perioperative management, a close monitoring (O2 saturation and pCO2) and the option for non-invasive ventilation have to be guaranteed.
Pneumologie 05/2009; 63(5):282-7.
ABSTRACT: Obesity is a well-established risk factor for perioperative pulmonary complications. Anaesthetic drugs and the effect of obesity on respiratory mechanics are responsible for these pathophysiological changes, but tracheal intubation with muscle relaxation may also contribute. This study evaluates the influence of airway management, i.e. intubation vs. laryngeal mask airway (LMA), on postoperative lung volumes and arterial oxygen saturation in the early postoperative period.
We prospectively studied 134 moderately obese patients (BMI 30) undergoing minor peripheral surgery. They were randomly assigned to orotracheal intubation or LMA during general anaesthesia with mechanical ventilation. Premedication, general anaesthesia and respiratory settings were standardized. While breathing air, we measured arterial oxygen saturation by pulse oximetry. Inspiratory and expiratory lung function was 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 (ANOVA) and t-test analysis. Statistical significance was considered to be P<0.05.
Postoperative pulmonary mechanical function was significantly reduced in both groups compared with preoperative values. However, within the first 24 h, lung function tests and oxygen saturation were significantly better in the LMA group (P<0.001; ANOVA).
In moderately obese patients undergoing minor surgery, use of the LMA may be preferable to orotracheal intubation with respect to postoperative saturation and lung function.
Acta Anaesthesiologica Scandinavica 03/2009; 53(4):436-42. · 2.19 Impact Factor
Regional Anesthesia and Pain Medicine 08/2008; 33(5):e42. · 4.08 Impact Factor
ABSTRACT: Membrane-bound heparan sulfate proteoglycans act as coreceptors for cytokines and are involved in cell-matrix or cell-cell adhesion. We have determined the gene expression of all four members of the syndecan-like integral membrane proteoglycans and of betaglycan, the transforming growth factor-beta type III receptor, in various types of isolated hepatic cells of the rat. Fat-storing cells express syndecan-1, -2, -3, -4, and betaglycan. During the transformation of fat-storing cells into myofibroblasts (the key process in the development of liver cirrhosis), the levels of mRNA for syndecan-1, -3, and -4 remain constant, whereas the amount of syndecan-2 mRNA increases and that for betaglycan decreases. Liver macrophages express syndecan-3 and -4, but only small amounts of syndecan-1. Freshly isolated hepatocytes express only syndecan-1, -2, and -4, but fail to express betaglycan. During cultivation, hepatocytes start to express betaglycan. Syndecan-3, -4, and betaglycan are transcribed into one mRNA population, whereas syndecan-1 and -2 are expressed in different-sized mRNA populations. The data show that the genes of all tested membrane heparan sulfate proteoglycans are expressed by hepatic cells, but that each cell type is characterized by its specific heparan sulfate proteoglycan mRNA profile.
Cell and Tissue Research 08/1996; 285(1):11-6. · 3.11 Impact Factor
ABSTRACT: It is still a subject of debate whether hepatocytes have the ability to express TGF-beta. Therefore, we investigated in freshly isolated and in monolayer cultures of rat hepatocytes the expression of TGF-beta isoform s at the RNA and protein level applying RT-PCR, immunocytochemistry, immunoblotting, and functional assays of TGF-beta. TFG-beta 1, -beta 2, and -beta 3 transcripts were detected in cultured cells, and the level of m RNA increased up to 48/72 h, but TGF-beta 1 transcripts were absent in freshly isolated cells. Using APAAP stainings the proteins of all three TGF-beta isoforms were observed in hepatocyte cultures from 5-96 h, but in hepatocytes in the liver in situ and in freshly isolated cell suspensions TGF-beta staining was negative. SDS-PAGE under reducing conditions followed by Western blotting detected in cell lysates the subunit of mature TGF-beta at about 13 kd. Analysis of TGF-beta bioactivity with the mink cell (Mv1Lu) proliferation inhibition assay and competitive radioligand assay confirmed in activated (i.e., acidified and subsequently neutralized) hepatocyte-conditioned media the presence of TGF-beta, which, however, is almost entirely in the latent form. It is concluded that TGF-beta can be expressed in cultured hepatocytes and that the level of expression is quickly upregulated under abnormal, not yet known, microenvironmental conditions.
Journal of Cellular Physiology 07/1996; 167(3):394-405. · 3.87 Impact Factor