Laparoscopic Roux-en-Y feeding jejunostomy as a long-term solution for severe feeding problems in children

Enteral feeding is a common problem in children with gastric emptying disorders. Traditional feeding methods in these patients often show a high rate of complications and maintenance issues. Laparoscopic Roux-en-Y feeding jejunostomy (LRFJ) has been described in a few patients as a minimal invasive option for enteral access in these children. The aim of this study is to evaluate the outcomes of the LRFJ procedure in our tertiary referral center. We conducted a retrospective case-series including all patients, aged 0-18 years old, that underwent a LFRJ procedure between August 2011 and December 2020 for the indication of oral feeding intolerance due to delayed gastric emptying. Outcomes evaluated were complications (short and long term) and parenteral satisfaction. In total, 12 children were identified that underwent LRFJ for the indication of oral feeding intolerance due to delayed gastric emptying. A total of 16 complications were noted in 8/12 patients (67%). Severity classified by Clavien-Dindo were grade I (n = 13), grade II (n = 1), and grade IIIB (n = 2). In 11/12 patients, parents were satisfied with the results.

CONCLUSIONS

Although minor complications after LRFJ are common in our patients, this technique is a safe solution in patients with gastric emptying disorders leading to a definitive method of enteral feeding and high parenteral satisfaction.

WHAT IS KNOWN

• Traditional tube feeding in children (duodenal, PEG-J-tubes) with severe delayed gastric emptying can be challenging with a high rate of complications and maintenance issues. • Open loop jejunostomy and Roux-en-Y jejunostomy are alternative, permanent methods of feeding but either invasive or are accompanied by severe complications. Little is known in the literature about laparoscopic Roux-en-Y feeding jejunostomy.

WHAT IS NEW

• Laparoscopic Roux-en-Y feeding jejunostomy is a permanent, safe and minimal invasive alternative option for enteral feeding in children with severe delayed gastric emptying..

Pain-related fear in adolescents with chronic musculoskeletal pain: process evaluation of an interdisciplinary graded exposure program

Background

For studying the effectiveness of treatment, it is important to check whether a new treatment is performed as originally described in the study-protocol.

Objectives

To evaluate whether an interdisciplinary graded exposure program, for adolescents with chronic musculoskeletal pain reporting pain-related fear, was performed according to protocol, and whether it is feasible to implement the program in rehabilitation care.

Methods

A process evaluation where quantitative and qualitative data on participant characteristics (adolescents, parents and therapists), attendance and participants’ opinion on the program were collected, by means of registration forms, questionnaires and group interviews. To evaluate treatment fidelity, audio and video recordings of program sessions were analyzed.

Results

Thirty adolescents were offered the program, of which 23 started the program. Adolescents attended on average 90% of the sessions. At least one parent per adolescent participated in the program. Analysis of 20 randomly selected recordings of treatment sessions revealed that treatment fidelity was high, since 81% of essential treatment elements were offered to the adolescents. The program was considered client-centered by adolescents and family-centered by parents. Treatment teams wished to continue offering the program in their center.

Conclusion

The interdisciplinary graded exposure program was performed largely according to protocol, and therapists, adolescents and their parents had a favorable opinion on the program. Implementation of the program in rehabilitation care is considered feasible.

Trial registration

Clinicaltrials.gov ID: NCT02181725 (7 February 2014).

89Zr-trastuzumab PET supports clinical decision making in breast cancer patients, when HER2 status cannot be determined by standard work up

Background

Up-to-date information on human epidermal growth factor receptor 2 (HER2) status in breast cancer (BC) is important, as expression can vary during the course of the disease, necessitating anti-HER2 therapy adjustments. Repeat biopsies, however, are not always possible. In this feasibility trial we assessed whether ⁸⁹Zr-trastuzumab PET could support diagnostic understanding and aid clinical decision making, when HER2 status could not be determined by standard work up. Additionally, HER2 status on circulating tumour cells (CTCs) was assessed.

Patients and methods

⁸⁹Zr-trastuzumab PET was performed in patients if disease HER2 status remained unclear after standard work up (bone scan, ¹⁸F-FDG PET, CT and if feasible a biopsy). PET result and central pathologic revision of available tumour biopsies were reported to the referring physician. CTC HER2 status prior to PET was evaluated afterwards and therefore not reported. Diagnostic understanding and treatment decision questionnaires were completed by the referring physicians before, directly after and ≥ 3 months after ⁸⁹Zr-trastuzumab PET.

Results

Twenty patients were enrolled: 8 with two primary cancers (HER2-positive and HER2-negative BC or BC and non-BC), 7 with metastases inaccessible for biopsy, 4 with prior HER2-positive and -negative metastases and 1 with primary BC with equivocal HER2 status. ⁸⁹Zr-trastuzumab PET was positive in 12 patients, negative in 7 and equivocal in 1 patient. In 15/20 patients, ⁸⁹Zr-trastuzumab PET supported treatment decision. The scan altered treatment of 8 patients, increased physicians’ confidence without affecting treatment in 10, and improved physicians’ disease understanding in 18 patients. In 10/20 patients CTCs were detected; 6/10 showed HER2 expression. CTC HER2 status was not correlated to ⁸⁹Zr-trastuzumab PET result or treatment decision.

Conclusion

⁸⁹Zr-trastuzumab PET supports clinical decision making when HER2 status cannot be determined by standard work up. The impact of CTC HER2 status needs to be further explored.

Electronic supplementary material

The online version of this article (10.1007/s00259-018-4099-8) contains supplementary material, which is available to authorized users.

Fear of pain and cortisol reactivity predict the strength of stress-induced hypoalgesia

Background

Acute stress can have an effect on pain sensitivity, yet the direction of the effect – whether it is hypoalgesic or hyperalgesic – is mixed across studies. Moreover, which part of the stress response influences pain sensitivity is still unclear. In the current experimental study, we aim to examine the effect of acute stress on heat pain thresholds and pain tolerance levels in healthy participants, while taking into account individual differences in stress responses.

Methods

Forty‐two healthy participants were randomly assigned to either a well‐validated stress paradigm: the Maastricht Acute Stress Task (MAST; combining physical and psychological stressors) or to a nonstressful version of the task. Heat pain thresholds and tolerance levels were assessed at three times: prior to the MAST, immediately after the MAST during the presumed sympatho‐adrenal medullary (SAM) response, and 15 min after MAST to cover the presumed hypothalamus–pituitary–adrenal (HPA) axis response. Stress responses were assessed both subjectively and physiologically.

Results

We observed that the acute stress induction led to increased heat pain thresholds, an effect that was present only in participants showing a cortisol response following stress induction and only in the presumed HPA axis time window. The strength of this hypoalgesic effect was further predicted by the change in cortisol and by fear of pain levels.

Conclusions

Our findings indicate that the HPA axis – and not the autonomic – stress response specifically underlies this stress‐induced hypoalgesic effect, having important implications for clinical states with HPA axis dysfunctions.

Significance

This experimental study shows that an acute stress induction – that combines physical and psychological stressors – increases heat pain thresholds, but not tolerance in healthy participants. Furthermore, the magnitude of this stress‐induced hypoalgesic effect is predicted by cortisol reactivity and fear of pain, revealing specific involvement of the HPA axis stress system and interactions with pain‐related psychosocial aspects.

Outcome after restorative proctocolectomy and ileal pouch–anal anastomosis in children and adults

Background

Studies comparing the outcome of ileal pouch–anal anastomosis (IPAA) in children and adults are scarce. This complicates decision-making in young patients. The aim of this study was to compare adverse events and pouch function between children and adults who underwent IPAA.

Methods

This cross-sectional cohort study included all consecutive children (aged less than 18 years) and adults with a diagnosis of inflammatory bowel disease or familial adenomatous polyposis who underwent IPAA in a tertiary referral centre between 2000 and 2015. Adverse events were assessed by chart review, and pouch function by interview using a pouch function score (PFS).

Results

In total, 445 patients underwent IPAA: 41 children (median age 15 years) and 404 adults (median age 39 years), with a median follow-up of 22 (i.q.r. 8–68) months. Being overweight (P = 0·001), previous abdominal surgery (P = 0·018), open procedures (P < 0·001) and defunctioning ileostomy (P = 0·014) were less common among children than adult patients. The occurrence of anastomotic leakage, surgical fistulas, chronic pouchitis and Crohn's of the pouch was not associated with paediatric age at surgery, nor was pouch failure. The development of anastomotic strictures was associated with having IPAA surgery during childhood (odds ratio 4·22, 95 per cent c.i. 1·13 to 15·77; P = 0·032). Pouch function at last follow-up was similar in the children and adult groups (median PFS 5·0 versus 6·0 respectively; P = 0·194).

Conclusion

Long-term pouch failure rates and pouch function were similar in children and adults. There is no need for a more cautious attitude to use of IPAA in children based on concerns about poor outcome.

Surgical management of children with intractable functional constipation; experience of a single tertiary children's hospital

BACKGROUND

Children with intractable functional constipation (FC) may eventually require surgery. However, guidelines regarding the surgical management of children with intractable FC are lacking. The aim of this study was to describe the surgical management of FC in children.

METHODS

A retrospective chart review was performed of children with FC (according to the Rome III criteria) who underwent ileostomy, colostomy or (sub)total colectomy at a tertiary hospital. Treatment success was defined as no longer fulfilling the Rome III-FC-criteria or having a functional ostomy. In addition, a self-developed questionnaire was administered to parents by telephone to assess postsurgical satisfaction (yes-no question and rated on a scale of 1-10).

KEY RESULTS

Thirty-seven patients (68% female) were included; median age at first surgery was 12 years (range 1.6-17.6). The initial surgical procedure consisted of ileostomy (n=21), colostomy (n=10), sigmoid resection (n=5) and subtotal colectomy (n=1). Success criteria were fulfilled by 85% of the patients. Postsurgical satisfaction of parents was 91% with a median postoperative satisfaction score of 8 (range 2-10), and 97% would opt for the same procedure(s) if necessary. Thirty patients (81%) experienced stoma problems, with 12 patients (32%) requiring stoma-revisions. Other complications occurred in 16 patients (43%).

CONCLUSIONS & INFERENCES

Surgery can improve symptoms in children with intractable FC. Despite morbidity and complications, parental satisfaction is high. Prospective, high-quality research is necessary to develop guidelines for the diagnostic work-up and surgical management in children with intractable FC.

Prognostic value of the standardized uptake value for (18)F-fluorodeoxyglucose in patients with stage IIIB melanoma

Purpose

FDG PET/CT is an excellent tool to detect melanoma metastases and also allows quantification of FDG uptake using standardized uptake value (SUV). The aim of this study was to prospectively investigate the potential prognostic value of SUV for disease-free survival (DFS) and disease-specific survival (DSS) for patients with stage IIIB melanoma.

Methods

From November 2003 to March 2008, all consecutive patients were included in the present study. Inclusion criteria were: palpable, histology- or cytology-proven lymph node metastases of melanoma, and referred to the University Medical Centre Groningen for FDG PET and CT examination. Patients without distant metastases were evaluated. Multivariable survival analysis was performed to determine whether SUV was associated with DFS and DSS (Cox proportional hazard analysis).

Results

In 80 patients (without distant metastases, 65 %) SUV could be measured. Overall 5-year DFS was 41 % (95% CI 26–56 %) and 24 % (95% CI 12–38 %) in patients with a low and high SUVmean (p = 0.02), respectively. Overall 5-year DSS was 48 % (95% CI 31–62 %) and 30 % (95% CI 17–45 %) in patients with a low and high SUVmean (p = 0.04), respectively. In the multivariable analysis, SUVmean was associated with DFS (hazard ratio 1.7; p = 0.048), but was not associated with DSS (hazard ratio 1.6; p = 0.1). The number of positive nodes, extranodal growth and gender were also associated with survival.

Conclusion

FDG uptake in clinically overt nodal melanoma metastases is inversely associated with DFS. Univariate analysis showed an association with DSS. However, after adjustment for potential confounders this association was no longer significant. If these findings are confirmed in larger studies, SUVmean could potentially be used (in addition to the number of positive nodes, tumour size and extranodal growth) as a factor in deciding on adjuvant systemic treatment.

Electronic supplementary material

The online version of this article (doi:10.1007/s00259-012-2182-0) contains supplementary material, which is available to authorized users.

Guided bone regeneration in rat mandibular defects using resorbable poly(trimethylene carbonate) barrier membranes

The present study evaluates a new synthetic degradable barrier membrane based on poly(trimethylene carbonate) (PTMC) for use in guided bone regeneration. A collagen membrane and an expanded polytetrafluoroethylene (e-PTFE) membrane served as reference materials. In 192 male Sprague-Dawley rats, a standardized 5.0mm circular defect was created in the left mandibular angle. New bone formation was demonstrated by post mortem micro-radiography, micro-computed tomography imaging and histological analysis. Four groups (control, PTMC, collagen, e-PTFE) were evaluated at three time intervals (2, 4 and 12 weeks). In the membrane groups the defects were covered; in the control group the defects were left uncovered. Data were analysed using a multiple regression model. In contrast to uncovered mandibular defects, substantial bone healing was observed in defects covered with a barrier membrane. In the latter case, the formation of bone was progressive over 12 weeks. No statistically significant differences between the amount of new bone formed under the PTMC membranes and the amount of bone formed under the collagen and e-PTFE membranes were observed. Therefore, it can be concluded that PTMC membranes are well suited for use in guided bone regeneration.

Quantitative multi-pinhole small-animal SPECT: uniform versus non-uniform Chang attenuation correction

Attenuation of photon flux on trajectories between the source and pinhole apertures affects the quantitative accuracy of reconstructed single-photon emission computed tomography (SPECT) images. We propose a Chang-based non-uniform attenuation correction (NUA-CT) for small-animal SPECT/CT with focusing pinhole collimation, and compare the quantitative accuracy with uniform Chang correction based on (i) body outlines extracted from x-ray CT (UA-CT) and (ii) on hand drawn body contours on the images obtained with three integrated optical cameras (UA-BC). Measurements in phantoms and rats containing known activities of isotopes were conducted for evaluation. In (125)I, (201)Tl, (99m)Tc and (111)In phantom experiments, average relative errors comparing to the gold standards measured in a dose calibrator were reduced to 5.5%, 6.8%, 4.9% and 2.8%, respectively, with NUA-CT. In animal studies, these errors were 2.1%, 3.3%, 2.0% and 2.0%, respectively. Differences in accuracy on average between results of NUA-CT, UA-CT and UA-BC were less than 2.3% in phantom studies and 3.1% in animal studies except for (125)I (3.6% and 5.1%, respectively). All methods tested provide reasonable attenuation correction and result in high quantitative accuracy. NUA-CT shows superior accuracy except for (125)I, where other factors may have more impact on the quantitative accuracy than the selected attenuation correction.

Effects of adjustable gastric banding on gastroesophageal reflux and esophageal motility: a systematic review

Controversial opinions exist concerning the effect of laparoscopic adjustable gastric banding on gastroesophageal reflux. MEDLINE and EMBASE databases were searched for relevant studies on patients undergoing adjustable gastric banding. Data are expressed in mean (range). Twenty studies were identified with a total of 3307 patients. The prevalence of reflux symptoms decreased postoperatively from 32.9% (16-57) to 7.7% (0-26.9) and medication use from 27.5% (16-38.5) to 9.5% (3.1-19.2). Newly developed reflux symptoms were found in 15% (6.1-20) of the patients. The percentage of esophagitis decreased postoperatively from 33.3% (19.4-61.6) to 27% (2.3-60.8). Newly developed esophagitis was observed in 22.9% (0-38.4). Pathological reflux was found in 55.8% (34.9-77.4) preoperatively and postoperatively in 29.4% (0-41.7) of the patients. Lower esophageal sphincter pressures increased from 12.9 to 16.9 mmHg (11.3-21.4). Lower esophageal sphincter relaxation decreased from 100% to 79.7% (58-86). The percentage of dysmotility increased from 3.5% (0-10) to 12.6% (0-25). Adjustable gastric banding has anti-reflux properties resulting in resolution or improvement of reflux symptoms, normalized pH monitoring results and a decrease of esophagitis on short term. However, worsening or newly developed reflux symptoms and esophagitis are found in a subset of patients during longer follow-up.

Sensitivity of 6-[F-18]fluoro-L-dihydroxyphenylalanine positron emission tomography for localizing tumors causing catecholamine excess

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Background: Positron emission tomography (PET) using the catecholamine precursor 6-[F-18]fluoro-L-dihydroxyphenylalanine (18F-DOPA) has emerged as promising technique to localize tumors with catecholamine excess. This study investigated the sensitivity of 18F-DOPA PET, compared to 123I-metaiodobenzylguanidine (123I-MIBG) scintigraphy and computer tomography (CT)/ magnetic resonance imaging (MRI) in patients with catecholamine excess. Methods: In a single center prospective study 18F-DOPA PET was compared to 123I-MIBG and CT/MRI in patients with catecholamine excess. The performance of each imaging modality was analyzed for individual patients and individual lesions. 18F-DOPA PET, 123I-MIBG, and CT/MRI were compared using a composite reference standard derived from all available imaging, clinical and histological information. Sensitivities were calculated and discordance between imaging techniques was compared. 18F-DOPA PET uptake was measured to determine whole body metabolic burden. Correlations between 18F-DOPA PET imaging and biochemical data were evaluated. Results: 48 patients were included. The tumor localization was found in 45 patients, 43 with 18F-DOPA PET, 31 with 123I-MIBG and 32 with CT/MRI, resulting with surgery in final diagnosis of pheochromocytoma in 40, adrenal hyperplasia in 2, paraganglioma in 2, ganglioneuroma in 1 and 3 unknown (as yet no lesion detected). Per patient based analysis showed sensitivities for 18F-DOPA PET, 123I-MIBG and CT/MRI of 90, 65 and 67% (P<.01 18F-DOPA PET vs 123I-MIBG, P<.01 18F-DOPA PET vs CT/MRI, P=1.0 123I-MIBG vs CT/MRI). Corresponding sensitivities in the lesion based analysis were 73, 48 and 44%, respectively (P<.001 for both 18F-DOPA PET vs 123I-MIBG and vs CT/MRI, P=.51 123I-MIBG vs CT/MRI). The 8F-DOPA PET+CT/MRI combination was superior to 123I-MIBG+CT/MRI (93 vs 76%, P<.001) Whole body metabolic burden measured with 18F-DOPA PET correlated with plasma free normetanephrine (r=.82) and 24h urinary total normetanephrine (r=.84) and metanephrine (r=.57). Conclusions: The sensitivity of 18F-DOPA PET to localize tumors with catecholamine excess is superior to either 123I-MIBG scintigraphy or CT/MRI.

No significant financial relationships to disclose.

Minimally invasive pediatric surgery: Increasing implementation in daily practice and resident's training

BACKGROUND

In 1998, the one-year experience in minimally invasive abdominal surgery in children at a pediatric training center was assessed. Seven years later, we determined the current status of pediatric minimally invasive surgery in daily practice and surgical training.

METHODS

A retrospective review was undertaken of all children with intra-abdominal operations performed between 1 January 2005 and 31 December 2005.

RESULTS

The type of operations performed ranged from common interventions to demanding laparoscopic procedures. 81% of all abdominal procedures were performed laparoscopically, with a complication rate stable at 6.9%, and conversion rate decreasing from 10% to 7.4%, compared to 1998. There were six new advanced laparoscopic procedures performed in 2005 as compared to 1998. The children in the open operated group were significantly smaller and younger than in the laparoscopic group (p < 0.001 and p = 0.001, respectively). The majority (64.2%) of the laparoscopic procedures were performed by a trainee. There was no difference in the operating times of open versus laparoscopic surgery, or of procedures performed by trainees versus staff surgeons. Laparoscopy by trainees did not have a negative impact on complication or conversion rates.

CONCLUSIONS

Laparoscopy is an established approach in abdominal procedures in children, and does not hamper surgical training.

Detecting fearful and neutral faces: BOLD latency differences in amygdala-hippocampal junction

Evolutionary survival and procreation are augmented if an individual organism quickly detects environmental threats and rapidly initiates defensive behavioral reactions. Thus, facial emotions signaling a potential threat, e.g., fear or anger, should be perceived rapidly and automatically, possibly through a subcortical processing route which includes the amygdala. Using event-related functional magnetic resonance imaging (fMRI), we investigated the time course of the response in the amygdala to neutral and fearful faces, which appear from dynamically decreasing random visual noise. We aimed to detect differences of the amygdala response between fearful and neutral faces by estimating the latency of the blood oxygenation level-dependent (BOLD) response. We found that bilateral amygdala-hippocampal junction activation occurred earlier for fearful than for neutral faces. Our findings support the theory of a dual route architecture in which the subcortical thalamic-hippocampal-amygdala route serves fast preconscious threat perception.

Effect of Laparoscopic Gastric Banding on Esophageal Motility

BACKGROUND

Alterations in esophageal motility may occur after placement of an adjustable gastric band as treatment for morbid obesity, near the gastro-esophageal junction. It causes an outlet obstruction, especially during follow-up after the band is filled.

METHODS

29 morbidly obese patients underwent conventional manometry preoperatively, 6 weeks postoperatively before and after filling the band and at 6 months postoperatively. A questionnaire was used to assess upper gastrointestinal symptoms during follow-up.

RESULTS

After band placement, there was a significant increase in lower esophageal sphincter (LES) end-expiratory pressure at 6 weeks with an empty band: 1.3 (0.9-1.9) kPa (median (interquartile range) (P=0.003), 6 weeks with a filled band: 2.1 (1.5-2.8) kPa (P=0.0001), and at 6 months: 1.5 (1.3-1.9) kPa (P=0.001), compared to the preoperative pressure: 0.8 (0.6-1.3) kPa. Also after band placement, the high pressure zone length increased (preop 5.0 (4.3-6.0) cm vs 6 weeks 6.0 (5.0-6.5) cm (P=0.003). The propagation of peristaltic contractions was not significantly altered after band placement. Heartburn decreased 6 weeks postoperatively (P=0.04) but increased at 6 months. Heartburn at 6 months was correlated with pouch formation (0.667; P<0.01).

CONCLUSION

Adjustable gastric band placement causes an increase in LES pressure and length of the high pressure zone. It decreases reflux symptoms in the short-term, but this effect appears not to be related to an effect on LES pressure or length. Pouch formation increases reflux symptoms without having any relationship to LES pressure and length. Band placement in the short-term does not disturb propagation of esophageal contractions.

Functional results after treatment of hip fracture: a multicentre, prospective study in 215 patients

OBJECTIVE

To find out which factors influence outcome after a fractured hip, so that the optimum treatment may be chosen for each patient.

DESIGN

Prospective cohort study.

SETTING

3 teaching and 2 rural hospitals, The Netherlands.

SUBJECTS

215 patients aged 55-102 years (median 82) who presented with a fractured hip during 1994.

INTERVENTIONS

Interviews shortly after the injury and 4 and 12 months later, study of radiographs, and evaluation of casenotes.

MAIN OUTCOME MEASURES

Mobility and functional recovery.

RESULTS

38 patients had died by the 4-month follow up, at which time 64/177 (36%) had regained the level of mobility that they had before the injury. At 12 months the figure was 58/148 (39%). The corresponding figures for functional recovery were 52/177 (29%) and 36/148 (24%). Factors that militated against recovery were increasing age, coexisting diseases, general complications and local complications.

CONCLUSIONS

The chance of a patient with a hip fracture making any further recovery after 4 months is minimal. Local complications are the most important risk factor.

Noninvasive continuous blood pressure measurement: a clinical evaluation of the Cortronic APM 770

The Cortronic APM 770 (Cortronic, Ronkonkoma, NY) is a commercial device that claims to measure blood pressure noninvasively and continuously with the use of a standard blood pressure cuff. The aim of our study was to assess the performance of the continuous-mode blood pressure readings of the Cortronic during anesthesia and surgery. We recorded blood pressure in 5 patients bilaterally. An interaarterial pressure (IAP) curve was recorded from 1 arm and the Cortronic pressure curve (CPC) was recorded from the other. For statistical analysis the period between 2 Cortronic recalibrations was defined as the intercalibration interval. The duration of these intervals ranged from 20 to 0.5 minutes. Four paired samples were drawn from each interval. The first sample in an interval represented the recalibration blood pressure; the other samples represented the continuous blood pressure. A total of 1,232 samples were taken, of which 308 were recalibration. The median of the differences and the 2.5th and 97.5th percentile limits of agreement were determined. Their respective values for diastolic and systolic recalibration measurements were 5, -17, and 34 mm Hg, and 6, -12, and 38 mm Hg. Their values for continuous measurements were 4, -23.5, and 32 mm Hg, and 6, -30, and 70 mm Hg. Changes in CPC were evaluated against changes in the corresponding IAP by plotting them in 4-quadrant graphs. In these graphs the Spearman rank correlations were between r = -0.17 and r = 0.01. We observed opposite CPC and IAP trends on 24 occasions during this study. We performed a simple simulation study to better understand the measurement method of the Cortronic.(ABSTRACT TRUNCATED AT 250 WORDS)

Is unified monitoring improving patient care?

We compared our standard method of data presentation in the operating room (i.e., using "front end" equipment) with a newly developed, computerized monitoring system called the data acquisition and display system. These two systems differed in that data presentation using the standard front-end equipment was scattered and poorly structured, whereas data obtained from the newly developed system were unified and integrated. To effect the comparison, we examined the "controllability" (i.e., the precision of control) by the anesthesiologist of hemodynamic variables: arterial systolic, mean, and diastolic pressures, mean pulmonary artery pressure, mean central venous pressure, and heart rate. Controllability was assumed to be an indictor of the quality of anesthesia. All perioperative data were stored every 15 seconds on a floppy disk, and these data were available for analysis. The controllability was quantified by calculating the surface area of the signal of a variable outside a defined control zone; the smaller this surface area, the greater the controllability. A Mann-Whitney-Wilcoxon statistical test was done to test whether the two different data presentation systems would result in different levels of controllability (the first zero hypothesis). A Kruskal-Wallis test was done to examine the "inter-anesthesiologist variability" between the two systems (the second zero hypothesis). Our data showed great variability. Looking for factors that might explain this, we found that if preoperative systolic blood pressure was greater than 160 mm Hg and diastolic pressure was greater than 95 mm Hg, hemodynamic variables fluctuated more widely. We could show no differences in controllability when the two systems were compared overall.(ABSTRACT TRUNCATED AT 250 WORDS)

The effectiveness of equipment for the users

To be effective in operation, equipment must be designed both to satisfy functional and economic criteria and to fit the man. This is done best within the concept of designing a complete man-machine system. Some of the methods to be used, and some of the important human factors aspects to be considered, are discussed and illustrated with examples from KLM at Amsterdam Airport.