Elderly patients often suffer from postoperative cognitive deficits (POCD) after serious surgical... more Elderly patients often suffer from postoperative cognitive deficits (POCD) after serious surgical operations. The reasons for this are not well understood. We investigated the influence of the invasiveness of the operation and the duration of the operation as well as the patient's preoperative physical status on measures of cognitive dysfunction. In a prospective study 59 elderly patients (mean age 69.2 years) were subjected to a neuropsychological test battery and a questionnaire following an abdominal surgical operation. The postoperative recovery with a focus on memory function was assessed using the Wechsler Memory Scale (WMS) seven days after the operation. Self-reported cognitive deficits were studied using the a questionnaire of experienced attention deficits (FEDA) three months after the operation. Postoperative psychological and self-reported test results varied as a function of the invasiveness and the duration of the operation. After more invasive operations patients ...
This randomized controlled, clinical prospective interventional trial was aimed at exploring the ... more This randomized controlled, clinical prospective interventional trial was aimed at exploring the effect of patient empowerment on short- and long-term outcomes after major oncologic surgery in elderly cancer patients. This trial was performed from February 2011 to January 2014 at two tertiary medical centers in Germany. The study included patients aged 65 years and older undergoing elective surgery for gastro-intestinal, genitourinary, and thoracic cancer. The patients were randomly assigned to the intervention group, i.e. patient empowerment through information booklet and diary keeping, or to the control group, which received standard care. Randomization was done by block randomization in blocks of four in order of enrollment. The primary outcome were 1,postoperative length of hospital stay (LOS) and 2. long-term global health-related quality of life (HRQoL) one year postoperatively. HRQoL was assessed using the EORTC QLQ C30 questionnaire. Secondary outcomes encompassed postoperative stress and complications. Further objectives were the identification of predictors of LOS, and HRQoL at 12 months. Overall 652 patients were included. The mean age was 72 ± 4.9 years, and the majority of patients were male (68.6%, n = 447). The ^median of postoperative length of stay was 9 days (IQR 7-14 day). There were no significant differences between the intervention and the control groups in postoperative LOS (p = 0.99) or global HRQoL after one year (women: p = 0.54, men: p = 0.94). While overall complications and major complications occurred in 74% and 24% of the cases, respectively, frequency and severity of complications did not differ significantly between the groups. Patients in the intervention group reported significantly less postoperative pain (p = 0.03) than the control group. Independent predictors for LOS were identified as severity of surgery, length of anesthesia, major postoperative complications, nutritional state, and pre-operative physical functional capacity measured by the Timed Up and Go-test by multiple robust regressions. Patient empowerment through information booklet and diary keeping did not shorten the postoperative LOS in elderly onco-surgical patients, but improved quality of care regarding postoperative pain. Postoperative length of stay is influenced by pre-operative nutritional state, pre-operative functional impairment, severity of surgery, and length of anesthesia. Clinicaltrials.gov. Identifier NCT01278537.
Commonly used anaesthetics can cause neurodegeneration in the developing brain. Sevoflurane, a wi... more Commonly used anaesthetics can cause neurodegeneration in the developing brain. Sevoflurane, a widely used substance in paediatric anaesthesia, has not been analysed thus far. This study was carried out to investigate the effects of sevoflurane on neuronal cell viability. Primary cortical neuronal cultures were prepared from Wistar rat embryos (E18), kept in 100 microl Gibco-Neurobasal-A medium and exposed to 4 and 8 Vol.% sevoflurane for up to 48 h. Cell viability was assessed using the methyltetrazolium assay and was related to untreated controls. To evaluate the role of gamma-aminobutyric acid type A receptors, untreated cells were preincubated with the receptor antagonists gabazine or picrotoxin and were subsequently exposed to 8 Vol.% sevoflurane and the receptor antagonist. Cell viability was assessed and compared with that of sevoflurane-treated controls. Up to 6 (8 Vol.%) and 12 h (4 Vol.%) of exposure to sevoflurane, cell viability was equal when compared with untreated controls. Only longer exposure times led to significantly lowered cell viability. After 12 h of exposure, no significant differences in cell viability were found between these two series. Cell viability of cultures treated with sevoflurane and the receptor antagonists showed no significant differences when compared with sevoflurane-exposed controls. These results suggest that sevoflurane does not cause neurodegeneration in primary cortical neurons of the rat following clinically relevant exposure times and concentrations.
Unconscious processing of words during general anesthesia has been suggested after surgery with s... more Unconscious processing of words during general anesthesia has been suggested after surgery with several tests of implicit memory. Patients can neither recall those words nor do they have explicit memories of other intraoperative events. It is unclear to what degree information is processed during general anesthesia and which tests are best suited to detect implicit memory. In the current study, a lexical decision paradigm not previously used to demonstrate implicit memory during anesthesia was used. Sixty patients undergoing lumbar disc surgery were assigned to receive isoflurane infusion- or propofol infusion-based anesthesia combined with alfentanil infusions and a nitrous oxide-oxygen mixture. A control group of 10 medical students listened to tapes without receiving anesthesia. Two tapes, each containing a list of 30 low-frequency German nouns repeated for 15 min, were prepared, with half of the patients listening to tape A and the other half listening to tape B during the operation. Exposure time was 15 min from the time of skin incision onward. In the test phase, approximately 7 h later, words from lists A and B plus 60 nonwords were presented in random order by a computer program. Subjects were asked to indicate, by pressing one of two response buttons, whether the spoken word was or was not a legal German word (lexical decision). A recognition test revealed chance recognition for words presented during anesthesia. Lexical decision responses, however, were slightly faster to primed (previously presented) words than to unprimed (not previously presented) words when the entire group of patients was tested, suggesting a small implicit memory effect, which barely failed to reach the significance level. When the two medication groups were tested separately, no significant implicit memory effect could be ascertained statistically. The effects of previous exposure were much more pronounced in the control group. Balanced anesthesia techniques with isoflurane or propofol lead to only a minimal, statistically borderline implicit memory effect in the lexical decision paradigm.
Elderly patients often suffer from postoperative cognitive deficits (POCD) after serious surgical... more Elderly patients often suffer from postoperative cognitive deficits (POCD) after serious surgical operations. The reasons for this are not well understood. We investigated the influence of the invasiveness of the operation and the duration of the operation as well as the patient's preoperative physical status on measures of cognitive dysfunction. In a prospective study 59 elderly patients (mean age 69.2 years) were subjected to a neuropsychological test battery and a questionnaire following an abdominal surgical operation. The postoperative recovery with a focus on memory function was assessed using the Wechsler Memory Scale (WMS) seven days after the operation. Self-reported cognitive deficits were studied using the a questionnaire of experienced attention deficits (FEDA) three months after the operation. Postoperative psychological and self-reported test results varied as a function of the invasiveness and the duration of the operation. After more invasive operations patients ...
This randomized controlled, clinical prospective interventional trial was aimed at exploring the ... more This randomized controlled, clinical prospective interventional trial was aimed at exploring the effect of patient empowerment on short- and long-term outcomes after major oncologic surgery in elderly cancer patients. This trial was performed from February 2011 to January 2014 at two tertiary medical centers in Germany. The study included patients aged 65 years and older undergoing elective surgery for gastro-intestinal, genitourinary, and thoracic cancer. The patients were randomly assigned to the intervention group, i.e. patient empowerment through information booklet and diary keeping, or to the control group, which received standard care. Randomization was done by block randomization in blocks of four in order of enrollment. The primary outcome were 1,postoperative length of hospital stay (LOS) and 2. long-term global health-related quality of life (HRQoL) one year postoperatively. HRQoL was assessed using the EORTC QLQ C30 questionnaire. Secondary outcomes encompassed postoperative stress and complications. Further objectives were the identification of predictors of LOS, and HRQoL at 12 months. Overall 652 patients were included. The mean age was 72 ± 4.9 years, and the majority of patients were male (68.6%, n = 447). The ^median of postoperative length of stay was 9 days (IQR 7-14 day). There were no significant differences between the intervention and the control groups in postoperative LOS (p = 0.99) or global HRQoL after one year (women: p = 0.54, men: p = 0.94). While overall complications and major complications occurred in 74% and 24% of the cases, respectively, frequency and severity of complications did not differ significantly between the groups. Patients in the intervention group reported significantly less postoperative pain (p = 0.03) than the control group. Independent predictors for LOS were identified as severity of surgery, length of anesthesia, major postoperative complications, nutritional state, and pre-operative physical functional capacity measured by the Timed Up and Go-test by multiple robust regressions. Patient empowerment through information booklet and diary keeping did not shorten the postoperative LOS in elderly onco-surgical patients, but improved quality of care regarding postoperative pain. Postoperative length of stay is influenced by pre-operative nutritional state, pre-operative functional impairment, severity of surgery, and length of anesthesia. Clinicaltrials.gov. Identifier NCT01278537.
Commonly used anaesthetics can cause neurodegeneration in the developing brain. Sevoflurane, a wi... more Commonly used anaesthetics can cause neurodegeneration in the developing brain. Sevoflurane, a widely used substance in paediatric anaesthesia, has not been analysed thus far. This study was carried out to investigate the effects of sevoflurane on neuronal cell viability. Primary cortical neuronal cultures were prepared from Wistar rat embryos (E18), kept in 100 microl Gibco-Neurobasal-A medium and exposed to 4 and 8 Vol.% sevoflurane for up to 48 h. Cell viability was assessed using the methyltetrazolium assay and was related to untreated controls. To evaluate the role of gamma-aminobutyric acid type A receptors, untreated cells were preincubated with the receptor antagonists gabazine or picrotoxin and were subsequently exposed to 8 Vol.% sevoflurane and the receptor antagonist. Cell viability was assessed and compared with that of sevoflurane-treated controls. Up to 6 (8 Vol.%) and 12 h (4 Vol.%) of exposure to sevoflurane, cell viability was equal when compared with untreated controls. Only longer exposure times led to significantly lowered cell viability. After 12 h of exposure, no significant differences in cell viability were found between these two series. Cell viability of cultures treated with sevoflurane and the receptor antagonists showed no significant differences when compared with sevoflurane-exposed controls. These results suggest that sevoflurane does not cause neurodegeneration in primary cortical neurons of the rat following clinically relevant exposure times and concentrations.
Unconscious processing of words during general anesthesia has been suggested after surgery with s... more Unconscious processing of words during general anesthesia has been suggested after surgery with several tests of implicit memory. Patients can neither recall those words nor do they have explicit memories of other intraoperative events. It is unclear to what degree information is processed during general anesthesia and which tests are best suited to detect implicit memory. In the current study, a lexical decision paradigm not previously used to demonstrate implicit memory during anesthesia was used. Sixty patients undergoing lumbar disc surgery were assigned to receive isoflurane infusion- or propofol infusion-based anesthesia combined with alfentanil infusions and a nitrous oxide-oxygen mixture. A control group of 10 medical students listened to tapes without receiving anesthesia. Two tapes, each containing a list of 30 low-frequency German nouns repeated for 15 min, were prepared, with half of the patients listening to tape A and the other half listening to tape B during the operation. Exposure time was 15 min from the time of skin incision onward. In the test phase, approximately 7 h later, words from lists A and B plus 60 nonwords were presented in random order by a computer program. Subjects were asked to indicate, by pressing one of two response buttons, whether the spoken word was or was not a legal German word (lexical decision). A recognition test revealed chance recognition for words presented during anesthesia. Lexical decision responses, however, were slightly faster to primed (previously presented) words than to unprimed (not previously presented) words when the entire group of patients was tested, suggesting a small implicit memory effect, which barely failed to reach the significance level. When the two medication groups were tested separately, no significant implicit memory effect could be ascertained statistically. The effects of previous exposure were much more pronounced in the control group. Balanced anesthesia techniques with isoflurane or propofol lead to only a minimal, statistically borderline implicit memory effect in the lexical decision paradigm.
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Papers by Maren Schmidt