Bioreactor and scaffold design for the mechanical stimulation of anterior cruciate ligament grafts.

Various studies have shown that physical stimuli modulate cell function and this has motivated the development of a bioreactor to engineer tissues in vitro by exposing them to mechanical loads. Here, we present a bioreactor for the physical stimulation of anterior cruciate ligament (ACL) grafts, whereby complex multi-dimensional strain can be applied to the matrices. Influences from environmental conditions to the behavior of different cells on our custom-made silk scaffold can be investigated since the design of the bioreactor allows controlling these parameters precisely. With the braided design of the presented silk scaffold we achieve maximum loads and stiffness values matching those of the human ACL. Thus, the existent degummed and wet silk scaffolds absorb maximum loads of 2030±109 N with stiffness values of 336±40 N/mm.

The laryngeal mask airway Supreme--a single use laryngeal mask airway with an oesophageal vent. A randomised, cross-over study with the laryngeal mask airway ProSeal in paralysed, anaesthetised patients.

The LMA Supreme is a new extraglottic airway device which brings together features of the LMA ProSeal, Fastrach and Unique. We test the hypothesis that ease of insertion, oropharyngeal leak pressure, fibreoptic position and ease of gastric tube placement differ between the LMA ProSeal and the LMA Supreme in paralysed anesthetised patients. Ninety-three females aged 19-71 years were studied. Both devices were inserted into each patient in random order. Two attempts were allowed. Digital insertion was used for the first attempt and guided insertion for the second attempt. Oropharyngeal leak pressure and fibreoptic position were determined during cuff inflation from 0 to 40 ml in 10 ml increments. Gastric tube insertion was attempted if there was no gas leak from the drain tube. First attempt and overall insertion success were similar (LMA ProSeal, 92% and 100%; LMA Supreme 95% and 100%). Guided insertion was always successful following failed digital insertion. Oropharyngeal leak pressure was 4-8 ml higher for the LMA ProSeal over the inflation range (p < 0.001). Intracuff pressure was 16-35 cm higher for the LMA ProSeal when the cuff volume was 20-40 ml (p < 0.001). There was an increase in oropharyngeal leak pressure with increasing cuff volume from 10 to 30 ml for both devices, but no change from 0 to 10 ml and 30-40 ml. There were no differences in the fibreoptic position of the airway or drain tube. The first attempt and overall insertion success for the gastric tube was similar (LMA ProSeal 91% and 100%; LMA Supreme 92% and 100%). We conclude that ease of insertion, gastric tube placement and fibreoptic position are similar for the LMA ProSeal and LMA Supreme in paralysed, anaesthetised females, but oropharyngeal leak pressure and intracuff pressure are higher for the LMA ProSeal.

Lornoxicam characteristically modulates cerebral pain-processing in human volunteers: a functional magnetic resonance imaging study.

BACKGROUND: Lornoxicam like other non-steroidal anti-inflammatory drugs (NSAIDs) is widely used for postoperative pain therapy. Evaluation of the effect of lornoxicam on cerebral processing of surgical pain was thus the aim of the present functional magnetic resonance imaging (fMRI) study. METHODS: An fMRI-compatible pain model that mimics surgical pain was used to induce pain rated 4-5 on a visual analogue scale (VAS) at the anterior margin of the right tibia in volunteers (n=22) after i.v. administration of saline (n=11) or lornoxicam (0.1 mg kg(-1)) (n=11). RESULTS: Lornoxicam, which significantly reduced pain sensation [VAS: mean (sd) 4.6 (0.7) vs 1.2 (1.5)], completely suppressed pain-induced activation in the SII/operculum, anterior cingulate cortex, insula, parietal (inferior), prefrontal (inferior, medial), temporal (inferior, medial/superior) lobe, cerebellum, and contralateral (e.g. left-sided) postcentral gyrus (SI). Only the hippocampus and the contralateral superior parietal lobe (BA 7) were activated. CONCLUSIONS: As compared with saline, lornoxicam typically suppressed pain-induced brain activation in all regions except the hippocampus. Furthermore, de novo activation was found in the contralateral, superior parietal lobe (BA 7).

Comparison of high- and low-dose intrathecal morphine for spinal fusion in children.

BACKGROUND: The purpose of this prospective study was to assess the blood-sparing effect, the quality of analgesia, and the incidence of side-effects of a low-dose regime of intrathecal opioids (ITO) when compared with those of a high-dose regime in scoliosis surgery in children. METHODS: Forty-six children were randomly included into one of the three groups to receive morphine 5 microg kg(-1) plus sufentanil 1 microg kg(-1) [low-dose intrathecal opioid (LITO)], morphine 15 microg kg(-1) plus sufentanil 1 microg kg(-1) [high-dose intrathecal opioid (HITO)] intrathecally, or no intrathecal opioid. Postoperative analgesia was provided by i.v. opioids. Intraoperative blood loss, postoperative quality of analgesia, opioid requirements, and the incidence of side-effects were recorded for 3 days. RESULTS: Intraoperative blood loss was significantly reduced by ITOs [LITO: 41.4 (sd 18.8) ml kg(-1); HITO: 37.5 (6.9) ml kg(-1); control: 76.9 (15.3) ml kg(-1), P<0.001], with no difference between the two intrathecal opioid groups. Mean pain scores on the day of surgery were lower in both intrathecal opioid groups (LITO: 2.2 and HITO: 2.1) when compared with the control group (4.1, P<0.03) and opioid consumption was significantly decreased [LITO: 304.3 (65.0) microg kg(-1); HITO: 224.1 (51.8) microg kg(-1); control: 667.7 (89.5) microg kg(-1), P<0.002]. Side-effects of intrathecally administered opioids were similarly frequent in all groups. CONCLUSIONS: Intrathecal administration of opioids significantly reduces blood loss and postoperative opioid demand, thereby showing side-effects comparable with the control group. These effects were already seen with the low-dose regimen and high dose did not further improve efficacy.

Bacterial contamination of anaesthetists' hands by personal mobile phone and fixed phone use in the operating theatre.

Following hand disinfection, 40 anaesthetists working in the operating room (OR) were asked to use their personal in-hospital mobile phone for a short phone call. After use of the cell phone, bacterial contamination of the physicians' hands was found in 38/40 physicians (4/40 with human pathogen bacteria). After repeating the same investigation with fixed phones in the OR anteroom 33/40 physicians showed bacterial contamination (4/40 with human pathogen bacteria). The benefit of using mobile phones in the OR should be weighed against the risk for unperceived contamination. The use of mobile phones may have more serious hygiene consequences, because, unlike fixed phones, mobile phones are often used in the OR close to the patient.

A study of airway management using the ProSeal LMA laryngeal mask airway compared with the tracheal tube on postoperative analgesia requirements following gynaecological laparoscopic surgery.

In a randomised double blind prospective study, we tested the hypothesis that postoperative pain is lower in patients who receive an ProSeal LMA laryngeal mask airway compared with a tracheal tube. One hundred consecutive female patients (ASA I-II, 18-75 years) undergoing laparoscopic gynaecological surgery were divided into two equal-sized groups for airway management with the ProSeal LMA or tracheal tube. Anaesthesia management was identical for both groups and included induction of anaesthesia using propofol/fentanyl, and maintenance with propofol/remifentanil, muscle relaxation with rocuronium, positive pressure ventilation, gastric tube insertion, dexamethasone/tropisetron for anti-emetic prophylaxis, and diclofenac for pain prophylaxis. All types of postoperative pain were treated using intravenous patient-controlled analgesia (PCA) morphine. Patients and postoperative staff were unaware of the airway device used. Data were collected by a single blinded observer. We found that pain scores were lower for the ProSeal LMA at 2 h and 6 h but not at 24 h. Morphine requirements were lower for the ProSeal LMA by 30.4%, 30.6% and 23.3% at 2, 6 and 24 h, respectively. Nausea was less common with the ProSeal LMA than with the tracheal tube at 2 h and 6 h but not at 24 h. There were no differences in the frequency of vomiting, sore throat, dysphonia or dysphagia. We conclude that postoperative pain is lower for the ProSeal LMA than the tracheal tube in females undergoing gynaecological laparoscopic surgery.

Postoperative nausea, vomiting, airway morbidity, and analgesic requirements are lower for the ProSeal laryngeal mask airway than the tracheal tube in females undergoing breast and gynaecological surgery.

BACKGROUND: We test the hypothesis that the frequency of postoperative nausea and vomiting is similar for the ProSeal laryngeal mask airway (LMA) and the tracheal tube. METHODS: Two hundred consecutive female patients (ASA I-II, 18-75 yr) undergoing routine breast and gynaecological surgery were divided into two equal-sized groups for airway management with the ProSeal LMA or tracheal tube. RESULTS: Ventilation was better and airway trauma less frequent for the ProSeal LMA. For the ProSeal group, the time spent in the post-anaesthesia care unit was shorter (69 vs 88 min, P < 0.0001); fewer doses of tropisetron were required in the post-anaesthesia care unit (P < or = 0.001) and ward (P = 0.004); morphine requirements were lower in the post-anaesthesia care unit (6.0 vs 8.1 mg, P = 0.005) and ward (6.1 vs 8.9, P = 0.004); nausea was less frequent at all times (overall: 13% vs 53%, P < 0.0001); vomiting was less frequent at 2 h (4% vs 18%, P = 0.003) and 24 h (5% vs 19%, P = 0.004); and sore throat was less frequent at all times (overall: 12% vs 38%, P < 0.0001). CONCLUSIONS: The ProSeal LMA reduced the absolute risk of postoperative nausea and vomiting by 40% (53-13%). In patients without the need for morphine, the ProSeal LMA reduced the absolute risk of postoperative nausea and vomiting by 23% (37-14%). We conclude that the frequency of postoperative nausea, vomiting, airway morbidity, and analgesic requirements is lower for the ProSeal LMA than the tracheal tube in females undergoing breast and gynaecological surgery.

Effect of total intravenous anaesthesia and balanced anaesthesia on the frequency of coughing during emergence from the anaesthesia.

BACKGROUND: The effects of total intravenous anaesthesia (TIVA) and balanced anaesthesia (BAL) on coughing during emergence from the general anaesthesia have not yet been compared. METHODS: Fifty patients, aged 18-60 yr, undergoing elective lumbar disk surgery were randomly allocated to undergo TIVA (propofol-remifentanil) or BAL (fentanyl-nitrous oxide-sevoflurane). Extubation was performed in the knee-elbow position, documented on video, and subsequently evaluated by blinded examiners. RESULTS: There was no difference between TIVA and BAL patients with respect to patient characteristics, proportion of smokers, surgical time, or time of emergence. The median number of coughs was significantly lower in the TIVA group (1, range 0-9) than in the BAL group (4, range 0-20, P = 0.007). Mean maximal heart rate and mean maximal arterial pressure measured during emergence were also significantly lower in the TIVA group (P = 0.009 and P = 0.006, respectively). CONCLUSIONS: During emergence from anaesthesia in the knee-elbow position, TIVA is associated with significantly less coughing and reduced haemodynamic response when compared with BAL.

[Management of accidental hypothermia]. / Management der akzidentellen Hypothermie.

Patients with hypothermia are frequently encountered in emergency medicine. Particularly trauma patients, but also other predisposed persons, can be expected to suffer from hypothermia at any time of the year. Therapy focuses not only on symptom-oriented intensive care to stabilize and secure vital functions, but also on rewarming. Even in cases of severe hypothermia with circulatory arrest, therapy can produce excellent results. This paper first gives a brief overview of the typical clinical symptoms of hypothermia, before giving a detailed description of the preclinical and in-hospital management of the hypothermia patient. The various rewarming strategies are the subject of special attention and critical evaluation.

Accidental intracerebroventricular injection of anaesthetic drugs during induction of general anaesthesia.

A 51-year-old patient scheduled for surgery under general anaesthesia was accidentally given remifentanil 150 microg and propofol 1% 10 ml through an intracerebroventricular totally implantable access port placed in the right infraclavicular region, which was mistakenly thought to be an intravenous line. Severe pain in the head and neck caused the mistake to be discovered rapidly, and 20 ml of a mixture of cerebrospinal fluid and the anaesthetic drugs were aspirated from the implantable access port. The patient suffered no apparent adverse neurological sequelae.

Incidence of coronary heart disease and cardiac events in patients undergoing kidney and pancreatic transplantation.

One major cause of graft loss after kidney transplantation or simultaneous kidney and pancreas transplantation is death of the recipient due to cardiac events. Records of 261 patients who underwent sole kidney (group A) or combined kidney-pancreas transplantation (group B) were retrospectively analyzed. Patients were divided into groups with basic cardiac evaluation (chest X-ray, electrocardiogram) and patients with additional diagnostics [echocardiography, exercise stress test, myocardial perfusion test, and coronary angiography (CAG)]. The results of the performed CAGs were as follows: proven coronary artery disease (CAD) in 22 patients (12.43%) in group A and 37 patients (44.05%) in group B; stenosis of one main coronary artery of 70% or greater in 8.47% (group A) and 16.67% (group B) of the patients. Subsequent revascularization procedures were performed in 15 candidates (8.47%) of group A and 11 (13.10%) of group B. The incidence of posttransplant cardiac events (PCE) was lower in recipients in both groups who underwent additional cardiac evaluation. Late postoperative deaths were reported in 3.45% of kidney recipients with no additional evaluation (group A), in 2.06% of patients with further diagnostics (group A), and in only 1.19% of patients with invasive pretransplant evaluation (group B). Patients with known CAD and no further invasive diagnostics or subsequent revascularization are at great risk. PCE were observed in three of seven patients in this subgroup. Careful cardiac evaluation including echocardiography, exercise stress test, myocardial perfusion test, and CAG is associated with a low incidence of PCE.

Maxillofacial fractures masking traumatic intracranial hemorrhages.

Maxillofacial trauma may mask intracranial injuries prompting intensive care treatment. The purpose of this study was to identify whether craniofacial fracture patterns predispose patients with maxillofacial fractures to different types of intracranial hemorrhages. Within 7 years, 6649 patients with craniomaxillofacial injuries were admitted for treatment. The charts of the patients were analyzed according to age, sex, cause and mechanism of injury, type and location of facial injury, and intracranial trauma; 2195 sustained maxillofacial fractures. Statistical analyses were followed by logistic regression analyses for the four main types of intracranial hemorrhage to determine the impact of the different maxillofacial fractures. Intracranial hemorrhages in 212 patients (9.7%) occurred as epidural (2.5%), subdural (4.3%), subarachnoid (5.3%), and intracerebral hemorrhages (6.3%). Le Fort, orbit, nose, zygoma, and maxillary fractures increased the risk for accompanying intracranial hemorrhage by two- to fourfold (P < 0.05). Basal skull fractures caused a multiplication of the risk up to 17-fold, while fractures of the cranial vault were associated with a risk up to 14-fold. Nearly 10% of patients with craniomaxillofacial fractures sustain intracranial hemorrhages requiring frequently immediate neurosurgical intervention. Those patients, suffering from central midface fractures and skull base fractures, are prone to highly significant elevated risks of intracranial hemorrhage.

Testing of a new pneumatic device to cause pain in humans.

BACKGROUND: Surgical pain typically combines superficial and deep pain. We wished to generate pain that resembled surgical pain, reliably and reproducibly, in volunteers. METHODS: We constructed a computer-controlled pneumatic device to apply pressure to the anterior tibia. The reproducibility of the pain was tested by rating the pressure that caused pain rated 4-5 on a visual analogue scale (VAS) on days 0, 7, and 24 in 10 volunteers. The effect of remifentanil (0.025, 0.05, 0.075, and 0.1 microg kg-1 min-1) on pain tolerance in another set of volunteers (n=11) was used as an indirect measure of the reliability of pain production. RESULTS: The pressure needed (0.7 (0.3) to 0.9 (0.4) atm (mean (SD)) to induce pain rated 4-5 (VAS) did not vary, showing long-term reproducibility of the method. When pressure was applied to cause increasing pain in volunteers (n=11) 0.05 microg kg-1 min-1 remifentanil increased pain tolerance by 50%. An approximate doubling of the dose (0.1 microg kg-1 min-1) increased pain tolerance significantly more. The linear logarithmic dose-effect relationship shows that the device causes pain reliably, and this can be reduced with opioid treatment. CONCLUSION: This pneumatic device can apply pain reliably and reproducibly.

[Evaluation of an established course of hospital management through structured telephone survey of former participants]. / Evaluierung eines etablierten Universitätslehrganges für Krankenhausmanagement durch telefonische Befragung ehemaliger Teilnehmer.

AIM OF THE STUDY: Participation in courses for health and hospital management is increasingly becoming a conditio sine qua non for candidates for executive positions in the health professions. The aim of this study was thus to evaluate the two-semester university course for health and hospital management offered by the University of Innsbruck since 1994. METHODS: A structured telephone survey was conducted to poll the participants (n = 184) of previous courses concerning time invested, cost-benefit ratio, quality of the course as well as implementation of course content. RESULTS: The university courses (n = 7) for health and hospital management of the University of Innsbruck evaluated in this study were rated in the upper half of the of the five-part scale (scores 2 to 3) for overall quality, cost-benefit ratio and implementation of course content. Only approx. 25 % of the course participants reported that the course had a positive influence on their career. The relatively high course fee was borne in part by the local hospital operator, a fact that had a certain influence on the selection of course participants. Participation in the course was largely made possible by exemptions from job duties (approx. 75 %) and to a lesser extent by vacation time (approx. 20 %) or time off for overtime (approx. 5 %). Of total absences from the course (3.18 +/- 3.41 d) 75 % was for job-related reasons, 6 % for illness and 19 % for other reasons. Overall, participants were absent more often, the larger the number of personnel in their department or clinic. CONCLUSION: All in all, the courses were considered important and recommendable, particularly with regard to communication, organization, time management and cost awareness. Streamlining (i. e. more content in less time), stronger practical orientation and a switch from mainly local to more international speakers would be important steps toward improving course quality. Thanks to its demonstrated quality, it can be said that the university course for health and hospital management held by the University of Innsbruck and evaluated in this study is certainly a worthwhile course offered in a still emerging market, namely one that will come under increasing pressure from the candidates for executive positions in the health professions to provide what is best for their careers and the health services industry in general.

Cerebral vasospasm and ischaemic infarction in clipped and coiled intracranial aneurysm patients.

The influence of the treatment modalities (clipping/coiling) on the incidence of vasospasm and ischaemic infarction in aneurysm patients is still judged controversially. The purpose of this study was to analyse and compare retrospectively cerebral vasospasm and ischaemic infarction, as well as neurological deficits and outcome within a large population of clipped and coiled patients with ruptured and unruptured aneurysms. Within a 2-year period, a total of 144 interventions (53 clipping/91 coiling) entered the study. Daily bilateral transcranial Doppler sonographic monitoring was performed to observe vasospasm development. All cerebral computed tomography (cCT) and magnetic resonance imaging (MRI) scans were reviewed with respect to occurrence and localization of ischaemic infarctions. Focal neurological deficits were recorded and clinical outcome was evaluated using the Glasgow Outcome Scale. Statistical analysis included the use of multivariate logistic regression models to find determinants of vasospasm, ischaemic infarction and neurological deficits. Altogether, vasospasm was detected after 77 (53.5%) interventions, 61.8% in females (P < 0.01). Clipped patients significantly more often exhibited vasospasms (69.8 vs. 44.0%, P < 0.005) and were treated 1 week longer at the intensive care unit (P < 0.005). Seventy-seven patients (53.5%) developed ischaemic infarctions, 62.3% after clipping and 48.4% after coiling (P > 0.05). In the multivariate analysis, aneurysm-rupture was the strongest predictor for vasospasm and vasospasm was the strongest predictor for infarction. Neurological deficits at discharge (46.5%) were independent of treatment modality, the same applied for the mean Glasgow Outcome Scores. There was no significant difference in mortality between surgical and endovascular treatment (9.4 vs. 12.1%). Whilst the vasospasm incidence was significantly higher after surgical treatment, ischaemic infarctions were only slightly more frequent. The incidence of neurological deficits and clinical outcome was similar in both treatment groups.