Visual metaphors on anaesthesia monitors do not improve anaesthetists' performance in the operating theatre.

BACKGROUND: Previous research using a metaphorical anaesthesia monitor, where dimensions of rectangles proportionally represent 30 patient variable values, showed improved performance in diagnosing adverse events compared with the standard monitor. Steady-state values were represented by a frame around each rectangle. We developed a similar metaphorical anaesthesia interface, but instead of presenting four relatively simple complications, we presented 10 complications of various levels of difficulty. Our simplified monitor presented variables that anaesthetists and trainees suggested as being essential for diagnosis. METHODS: Thirty-two anaesthetists and anaesthesia trainees participated in the monitoring task. Three types of monitors were presented: standard monitor, metaphorical monitor, and metaphorical monitor with trend arrows emphasizing the direction of change. The subjects were presented with screenshots of the three monitor types displaying anaesthesia-related complications. They were asked to indicate treatment method and diagnosis for the displayed complication. RESULTS: No significant differences were found in time to diagnosis and accuracy between the metaphorical and standard monitor. There were also no differences between trend and no-trend monitors. Forty per cent of the complications were identified incorrectly. CONCLUSIONS: Visual metaphors on anaesthesia monitors do not improve anaesthetists' performance in the operating theatre. Since all complications in this study were identifiable based on monitor values alone, it seems feasible to develop a decision support system (DSS) based on these values. We suggest that a DSS could support the anaesthetist by calling attention to diagnoses that may not be considered.

A comparison of the clinical use of the Laryngeal Tube S and the ProSeal Laryngeal Mask Airway by first-month anaesthesia residents in anaesthetised patients.

The Laryngeal Tube S and the LMA-ProSeal are supraglottic instruments with an improved airway seal and a drainage tube to protect against regurgitation and to facilitate passage of a gastric tube. We compared the feasibility of these two instruments in a randomised, controlled clinical trial. One hundred and sixty patients were randomly allocated to undergo insertion of a Laryngeal Tube S (n = 82) or an LMA-ProSeal (n = 78). All insertions were carried out by first-month anaesthesia residents. Success rates were not significantly different: Laryngeal Tube S 89%, LMA-ProSeal 95%. There was also no significant difference in leak pressure or insertion time. Insertion time decreased significantly when we compared the first with the last 10 insertions. Gastric tube placement was successful in all patients in the Laryngeal Tube S group, but failed in 12 patients in the LMA-ProSeal group (p < 0.001). Dysphagia was reported by 22% of Laryngeal Tube S group and 3% of LMA-ProSeal group (p = 0.001). These findings demonstrate the applicability of the devices and a learning effect in the hands of anaesthesia residents with limited experience.

Diffuse choroidal haemangioma in Sturge-Weber syndrome treated with photodynamic therapy under general anaesthesia.

PURPOSE: To report the treatment outcome of photodynamic therapy with verteporfin (PDT) for exudative retinal detachment associated with diffuse choroidal haemangioma in Sturge-Weber syndrome. METHODS: An interventional case report of a 12-year-old girl with Sturge-Weber syndrome who developed an exudative retinal detachment (visual acuity 20/400) that was treated with PDT under general anaesthesia. PDT was performed according to the standard (macular degeneration) protocol, using three nonoverlapping spots of 4,000 microm. RESULTS: Subretinal fluid resolved completely over a period of 5 months and visual acuity increased to 20/50. No side effects of the PDT treatment were encountered during 9 months' follow-up. CONCLUSION: In our patient PDT with verteporfin effectively resolved the exudative retinal detachment associated with a diffuse choroidal haemangioma. Resolution of subretinal fluid occurred over several months without retreatment. We noted no side effects of the combination PDT and general anaesthesia, nor did we encounter ocular side effects of the treatment.

Evaluation of the development of lung hypoplasia in the premature lamb.

BACKGROUND: The death rate from human diaphragmatic hernia (CDH) ranges from 50 to 80%, mainly due to the associated lung hypoplasia. To prevent these irreversible pathological and physical defects, the question of intrauterine surgical intervention arises. The histological changes of the lung tissue after inducement of a diaphragmatic hernia were examined. Of special interest was the time elapsing until the development of lung hypoplasia. METHODS: A model of intrauterine inducement of diaphragmatic hernia was established using five fetal lambs to study consecutive pulmonary hypoplasia. Inducement of a diaphragmatic hernia was undertaken between 105 and 108 days' gestation. Lung tissue was examined histologically on postoperative days 8, 17, 21, 22, and 25 after inducement of the defect. RESULTS: On postoperative days 8, 17, and 21, no signs of pulmonary hypoplasia were found on histological examination. A pulmonary hypoplasia was found in two fetuses (on the 22nd and 25th postoperative day). The pathological and anatomical examination of a unilateral pulmonary hypoplasia after a short period of time shows that the artificially created diaphragmatic defect is a good model for producing a congenital diaphragmatic hernia. DISCUSSION: The severity of the pulmonary hypoplasia is related to the duration of lung compression by the herniated organs. The time elapsing until the development of lung hypoplasia is shorter than expected. Tracheal occlusion seems to be an effective strategy for treatment of the defect CDH, but the best technique for achieving occlusion, and particularly the ideal point in time to carry out "Fetendo," are unknown. Further research into this congenital illness is required in order to treat it.

[Comparison of sonographic weight estimation to actual birth weight: a retrospective analysis]. / Wertigkeit der ultrasonographischen Gewichtsschätzung im Vergleich zum Geburtsgewicht: Eine retrospektive Anlayse.

AIM: This retrospective study aims at determining the accuracy of sonographic estimation of birth weight based on ultrasound examinations performed at the department of gynaecology of Philipps University at Marburg, Germany. METHOD: 630 children were born at the university department of gynaecology during the first six months of 1998. 519 babies had been examined sonographically and their birth weight estimated within ten days prior to delivery. 176 (33,91 %) of these examinations were carried out by experienced sonographers complying to the level II standard of performance set out by DEGUM. 343 (66.09 %) of examinations were performed by less experienced junior doctors at the time of the mothers' admission to the delivery room. Two reference tables published by Hansmann und Ferrero were used to estimate birth weight. RESULTS: The lower and upper quartile of deviation between estimated weight and actual weight came to -200 g and + 200 g using the Hansmann method and -180 g and + 220 g respectively based on the method of Ferrero. It has to be noted that even greater differences occurred: the 10 % least exact estimates deviated by 500 g and more. The difference between estimated and actual weight increased with the length of pregnancy. The fully trained physician (DEGUM II) tended to estimate the birth weight more accurately. The average birth weight estimated sonographically was lower in "DEGUM II-babies" than that of children whose weight was estimated at the point of admission to the delivery room (Mann-Whitney p < 0,0001). Junior doctors showed a tendency to over-estimate the birth weight of babies actually being underweight. The opposite happened with babies who presented a relatively higher birth weight: their projected birth weight was underestimated. On the other hand, the regression line of the sonographic estimations of birth weight performed by the expert (level II DEGUM) fit to the expected bisector of the angle (Passing-Bablock p > 0,05). CONCLUSION: When clinical decisions are based on estimated values of birth weight, the possible deviation of this value from the actual weight has to be taken into account. In our study this difference came up to 500 g independent of the level of the examiner's ultrasonographic training.

[Acute situations in the dental chair: patient who does not respond well]. / Acute situatie in tandartsstoel: patiënt onwel.

In daily practice a dentist may encounter a patient with a diminution of consciousness or being short of breath. In this paper a treatment strategy has been described for diagnosis and treatment of acute situations in daily dental practice.

Venous air embolism, preservation/reperfusion injury, and the presence of intravascular air collection in human donor livers: a retrospective clinical study.

In human liver transplantation, air embolism is seldom encountered after graft reperfusion. Nevertheless, despite adequate flushing and clamping routines, air emboli have been reported in transesophageal echocardiography (TEE) studies performed during the reperfusion phase. We retrospectively investigated whether air in the donor liver -- as observed with pretransplant magnetic resonance imaging (MRI) -- resulted in clinical air embolism or contributed to preservation/reperfusion injury. Clinical air embolism was assessed by intraoperative hemodynamics and end-tidal CO2 monitoring. Preservation/reperfusion injury was assessed in postoperative biochemical measurements. The outcomes were compared between patients receiving livers containing significant intrahepatic air and patients receiving livers without intrahepatic air. Forty-three livers were studied, seven which had major intrahepatic air and ten of which had no evidence of air collections. Twenty-six livers showed minor amounts of air and were excluded from further study. One patient who received a liver that did not contain intrahepatic air had clinical evidence of air embolism. Clinical air embolism did not appear to be associated with the presence of significant intrahepatic air based upon pretransplant MRI. Intrahepatic air did not seem to affect the amount of preservation/reperfusion injury. Our data indicate that air bubbles in the portal and arterial branches are absorbed during reperfusion and that the majority of intrahepatic air is effectively removed by the specific flushing routines.

[Laparoscopic cholecystectomy and continuing surgical education]. / Laparoskopische Cholezystektomie und chirurgische Weiterbildung.

The rapid spread of laparoscopic cholecystectomy as standard operative treatment of cholelithiasis raises the question whether this new technique can be learned as prescribed for the traditional training of surgeons. To answer this question traditional methods of instruction were used for the first consecutive 100 laparoscopic cholecystectomies after the instructors had seen the method elsewhere and learned by operations on animals. 15 surgeons operated on these 100 patients (23 men and 77 women; mean age 50 [20-79] years). In accordance with the concept of early integration of laparoscopic cholecystectomy into surgical training, two trainee surgeons who had not yet performed a conventional cholecystectomy also took part in laparoscopic cholecystectomies. There were one serious (damage to the hepatocholedochal duct) and two mild (postoperative colics) complications. The median duration of operation was 95 (30-240) min. In eight patients the intervention was continued as a conventional cholecystectomy. This experience demonstrates that training in laparoscopic surgery can follow the same path as that for conventional surgery. A prerequisite is responsible assistance by an experienced operator, after the method has been introduced into the hospital.