Indication, performance and outcomes of adrenal vein sampling in patients with primary hyperaldosteronism

Primary hyperaldosteronism (PAH) is an important cause of secondary hypertension (HTN). The study of the same requires a high clinical suspicion in addition to a hormonal study that confirms hormonal hypersecretion. It is important to start the appropriate treatment once the diagnosis is confirmed, and for this is necessary to demonstrate whether the hormonal hypersecretion is unilateral (patients who could be candidates for surgical treatment) or bilateral (patients who are candidates for pharmacological treatment only). At the Hospital del Mar since 2016 there has been a multidisciplinary work team in which Nephrologists, Endocrinologists, Radiologists and Surgeons participate to evaluate cases with suspected hyperaldosteronism and agree on the best diagnostic-therapeutic approach for these patients, including the need for adrenal vein sampling, which is a technique that in recent years has become the gold standard for the study of PAH. In the present study we collect the experience of our centre in performing AVC and its usefulness for the management of these patients.

Importance of in situ preservation of parathyroid glands during total thyroidectomy

Background

Parathyroid failure is the most common complication after total thyroidectomy but factors involved are not completely understood. Accidental parathyroidectomy and parathyroid autotransplantation resulting in fewer than four parathyroid glands remaining in situ, and intensity of medical treatment of postoperative hypocalcaemia may have relevant roles. The aim of this study was to determine the relationship between the number of parathyroid glands remaining in situ and parathyroid failure after total thyroidectomy.

Methods

Consecutive patients undergoing first-time total thyroidectomy were studied prospectively, recording the number of Parathyroid Glands Remaining In Situ (PGRIS = 4 − (glands autografted + glands in the specimen)) and the occurrence of postoperative hypocalcaemia, and protracted and permanent hypoparathyroidism. Demographic, disease-related, laboratory and surgical variables were recorded. Patients were classified according to the PGRIS number into group 1–2 (one or two PGRIS), group 3 (three PGRIS) and group 4 (all four glands remaining in situ), and were followed for at least 1 year.

Results

A total of 657 patients were included, 43 in PGRIS group 1–2, 186 in group 3 and 428 in group 4. The prevalence of hypocalcaemia, and of protracted and permanent hypoparathyroidism was inversely related to the PGRIS score (group 1–2: 74, 44 and 16 per cent respectively; group 3: 51·1, 24·7 and 6·5 per cent; group 4: 35·3, 13·1 and 2·6 per cent; P < 0·001). Intact parathyroid hormone concentrations at 24 h and 1 month were inversely correlated with PGRIS score (P < 0·001). Logistic regression identified PGRIS score as the most powerful variable influencing acute and chronic parathyroid failure. In addition, a normal–high serum calcium concentration 1 month after thyroidectomy influenced positively the recovery rate from protracted hypoparathyroidism in all PGRIS categories.

Conclusion

In situ parathyroid preservation is critical in preventing permanent hypoparathyroidism after total thyroidectomy. Active medical treatment of postoperative hypocalcaemia has a positive synergistic effect.

Prospective study on loss of signal on the first side during neuromonitoring of the recurrent laryngeal nerve in total thyroidectomy

Background

Staged thyroidectomy has been recommended when loss of the signal from intraoperative nerve monitoring is observed after first-side dissection of the recurrent laryngeal nerve. There is no high-quality evidence supporting this recommendation. In addition, it is not clear whether signal loss predicts postoperative vocal cord paralysis.

Methods

This was a prospective observational study of consecutive adult patients undergoing neuromonitored total thyroidectomy for either malignancy or multinodular goitre. The prevalence of first-side loss of signal was recorded. Surgery was completed, and vagus and laryngeal nerves on the first side were rechecked at the end of the procedure.

Results

Two-hundred and ninety patients were included. Loss of signal on the first side was noted in 16 procedures (5·5 per cent). Thyroidectomy was completed and, at retesting, 15 of 16 initially silent nerves recovered an electromyographic signal with a mean(s.d.) amplitude of 132(26) mcV. Mean time to recovery was 20·2 (range 10–35) min. In no patient was the signal lost on the opposite side. Only three of 15 nerves with a recovered signal were associated with transient vocal cord dysfunction.

Conclusion

After loss of signal of the recurrent laryngeal nerve dissected initially, there was a 90 per cent chance of intraoperative signal recovery. In this setting, judicious bilateral thyroidectomy can be performed without risk of bilateral recurrent nerve paresis.

Vitamin d status in patients operated for primary hyperparathyroidism: comparison of patients from southern and northern europe

Aim. The interaction between vitamin D deficiency and primary hyperparathyroidism (PHPT) is not fully understood. The aim of this study was to investigate whether patients with PHPT from Spain and Sweden differed in vitamin D status and PHPT disease activity before and after surgery. Methods. We compared two cohorts of postmenopausal women from Spain (n = 126) and Sweden (n = 128) that had first-time surgery for sporadic, uniglandular PHPT. Biochemical variables reflecting bone metabolism and disease activity, including levels of 25-hydroxy vitamin D3 (25(OH)D) and bone mineral density, BMD, were measured pre- and one year postoperatively. Results. Median preoperative 25(OH)D levels were lower, and adenoma weight, PTH, and urinary calcium levels were higher in the Spanish cohort. The Spanish patients had higher preoperative levels of PTH (13.5 versus 11.0 pmol/L, P < 0.001), urinary calcium (7.3 versus 4.1 mmol/L, P < 0.001), and heavier adenomas (620 versus 500 g, P < 0.001). The mean increase in BMD was higher in patients from Spain and in patients with vitamin D deficiency one year after surgery. Conclusion. Postmenopasual women with PHPT from Spain had a more advanced disease and lower vitamin 25(OH)D levels. Improvement in bone density one year after surgery was higher in patients with preoperative vitamin D deficiency.

Outcome of protracted hypoparathyroidism after total thyroidectomy

BACKGROUND

Although the variables that influence the development of post-thyroidectomy hypocalcaemia are now better understood, the risk factors and long-term outcome of persistent hypoparathyroidism (HPP) are poorly defined. A retrospective review of a prospective protocol for the management of post-thyroidectomy hypocalcaemia was performed.

METHODS

Patients with a serum calcium level below 8 mg/dl (2 mmol/l) 24 h after total thyroidectomy were prescribed oral calcium with or without calcitriol and followed for at least 1 year. Protracted HPP was defined as an intact parathyroid hormone (iPTH) level below 13 pg/ml and need for calcium medication at 1 month after thyroidectomy.

RESULTS

Of 442 patients (343 with goitre, 99 with carcinoma) undergoing total thyroidectomy, 222 (50.2 per cent) developed postoperative hypocalcaemia. Eleven patients were lost to follow-up. Parathyroid function recovered in 131 patients within 1 month and 80 developed protracted HPP, which was associated with lymphadenectomy, fewer than three glands left in situ and incidental parathyroidectomy. Parathyroid function recovered within 1 year in 78 per cent of patients with protracted HPP. Factors associated with late recovery of parathyroid function were higher serum calcium and low but detectable iPTH levels 1 month after surgery. These factors were associated with higher calcitriol and calcium dosages at hospital discharge. Parathyroid autotransplantation did not protect against permanent HPP.

CONCLUSION

Higher serum calcium levels at 1 month after total thyroidectomy are associated with recovery of parathyroid function. It is hypothesized that intensive medical treatment of hypocalcaemia-'parathyroid splinting'-may improve the outcome of patients with protracted HPP.

Weight difference between double parathyroid adenomas is the cause of false-positive IOPTH test after resection of the first lesion

BACKGROUND

Some patients with double parathyroid adenoma show a greater than 50% decline in intraoperative parathyroid hormone (IOPTH) after resection of the first lesion. The present study was designed to test the hypothesis that significant adenoma weight differences may explain this inappropriate decline of IOPTH.

METHODS

We reviewed prospective database records at two tertiary institutions. Patients with a histopathologic diagnosis of double adenoma and no familial history of hyperparathyroidism were included. Diagnosis of double adenoma was confirmed either preoperatively (double uptake), intraoperatively (bilateral exploration), or at reintervention. IOPTH was determined following the Miami protocol. The 10-min postexcision sample was considered as the 0-min sample for IOPTH determinations at the time of resection of the second lesion.

RESULTS

Thirteen patients met the inclusion criteria. After resection of the first lesion, IOPTH failed to decline in four patients and a second adenoma was removed. They had similar weight (404 vs. 598 mg). In nine patients IOPTH showed a false greater than 50% decline. These patients had the largest adenoma removed first (846 +/- 226 mg), and only two had normal PTH serum concentrations 10 min after resection. The second adenoma was always smaller (284 +/- 177 mg; P = 0.02) and its resection either during the same operation (7 cases) or at reoperation (2 cases) led to normalization of IOPTH at 10 min in all cases.

CONCLUSIONS

Two-thirds of patients with double parathyroid adenoma show a false-positive decline of IOPTH after resection of the first adenoma. This appears to be due to the initial removal of the larger lesion.

Effect of parathyroidectomy for primary hyperparathyroidism on bone mineral density in postmenopausal women

Background

The bone mineral density (BMD) response to parathyroidectomy is heterogeneous and difficult to predict. Available data come from mixed populations of men and women, of different age and degrees of disease severity, and preoperative BMD loss.

Methods

This was a longitudinal, prospective cohort study of 103 postmenopausal women with osteopenia or osteoporosis at the femoral neck site, successfully operated on for primary hyper parathyroidism. BMD and metabolic variables were recorded before and 1 year after parathyroidectomy.

Results

After surgery, there was a 1·3 per cent increase in the median BMD at the femoral neck site (0·615 versus 0·623 g/cm2; P = 0·001). Overall, positive responses were also observed at total hip (0·4 per cent) and lumbar spine (2·3 per cent) sites. Analysing the individual responses, however, only 45 (46 per cent) of 97 patients showed a significant (at least 3·7 per cent) increase in BMD at the femoral neck site compared with the preoperative value and 52 had a decreased (15) or unchanged (37) femoral neck BMD. Patients who gained BMD were younger, had more severe hyperparathyroidism and better renal function.

Conclusion

Almost half of the postmenopausal women with hyperparathyroidism and low BMD have a significant remineralization response 1 year after parathyroidectomy. Differential mineralization responses of BMD after surgery appear to be related to severity of primary hyperparathyroidism, age and renal function.

Risk factors for transient vocal cord palsy after thyroidectomy

Background

Transient recurrent laryngeal nerve palsy affects to 5–10 per cent of patients after extracapsular thyroidectomy. This prospective study assessed the impact of surgical injury and extralaryngeal branching of the inferior laryngeal nerve (ILN) on vocal cord dysfunction (VCD).

Methods

Total thyroidectomy or lobectomy was performed in 188 patients, with 302 ILNs at risk. The anatomy of the ILN and degree of injury to the nerve, based on the Laryngeal Nerve Injury Score (LNIS), were recorded. Fibreoptic laryngoscopy was performed a mean(s.d.) of 10·6(4·1) days after thyroidectomy.

Results

Some 37·4 per cent of ILNs showed extralaryngeal branching. In all, 10·9 per cent of patients developed VCD; 4·3 per cent had paresis and 6·6 per cent paralysis. All paretic and all but one paralytic cords recovered fully after 61(17) days. VCD was more frequently associated with branched than non-branched ILNs (15·8 versus 8·1 per cent; P = 0·022). Injuries were more common in branched nerves (mean(s.e.m.) total LNIS 0·94(0·08) versus 0·51(0·05); P &lt; 0·001). Branched nerves were more likely to be associated with VCD (odds ratio 2·2 (95 per cent confidence interval 1·1 to 4·5)).

Conclusion

Branched ILNs suffer more surgical injuries and are twice as likely to be associated with VCD.

Usefulness of preoperative Tc-mibi parathyroid scintigraphy in secondary hyperparathyroidism

BACKGROUND AND AIMS

The usefulness of Tc-mibi parathyroid scintigraphy (Tc-PS) in planning parathyroidectomy for secondary hyperparathyroidism is not well known. The aim of this study was to review our experience with Tc-PS concerning: (1) the identification of hyperplastic glands, (2) detection of major ectopias and (3) prevention of recurrences.

PATIENTS AND METHODS

Thirty-three consecutive patients undergoing first-time subtotal parathyroidectomy for renal hyperparathyroidism had a dual-phase planar Tc-PS performed, and glands were classified as detected, weak, or not detected. The number and position of visualized glands were determined. Parathyroid weight, histology, and their relationship to Tc-PS were recorded after surgery.

RESULTS

Of 132 potential glands, 48 (35%) were localized on the Tc-PS and 128 (96.9%) were identified intraoperatively. Tc-PS positive/weak glands were heavier than nonlocalized glands. Tc-PS contributed to successful surgery in four patients with a single difficult gland each (three retrieved from the neck and one--fifth gland--requiring mediastinotomy). There was one persistence (3%) because of a missed fourth undescended inferior parathyroid gland. Two recurrences 2 years after surgery were due to a fifth thoracic gland not shown in the preoperative Tc-PS.

CONCLUSIONS

Preoperative Tc-PS helped in the intraoperative identification of moderate or major ectopias in 4/33 patients but was not useful to prevent recurrences from highly ectopic glands not visualized before first-time surgery.

Nodal yield, morbidity, and recurrence after central neck dissection for papillary thyroid carcinoma

BACKGROUND

The role of central neck dissection (CND) in differentiated thyroid cancer remains controversial. This study aims at elucidating the potential benefits and drawbacks of CND associated to total thyroidectomy in papillary cancer.

METHODS

Protocols of patients undergoing total thyroidectomy and CND for papillary cancer were reviewed. The following data were recorded: macroscopic appearance of central nodes; nodes obtained at operation; number of metastatic nodes and parathyroid glands incidentally resected; metastases, age, completeness, invasiveness, size score; postoperative s-Ca; complications; and recurrences. Differences between therapeutic (gross nodal involvement) and prophylactic (no apparent node involvement) CNDs were studied.

RESULTS

Forty-three patients (mean age, 52 +/- 17 years) were studied. A mean of 8.4 +/- 6.6 nodes were resected per patient. A 60% prevalence (26/43) of presence of nodal involvement (N+) was found with no difference between low- and high-risk patients. Twenty-five (60%) patients developed transient hypocalcemia, which was associated with incidental parathyroidectomy, number of nodes resected, and thymectomy. Two patients (4.6%) developed permanent hypoparathyroidism and 3 (7%), transient vocal cord paralysis. Parathyroid glands were found in 19% of the specimens. At follow-up, there were no central neck recurrences, but 5 patients developed lateral recurrences despite treatment with I(131). All 5 patients had had therapeutic CND with 6 or more metastatic nodes obtained in the CND specimen. No lateral neck recurrences were observed after prophylactic CND or in patients with < 6 nodes involved.

CONCLUSIONS

CND prevents central neck recurrences. Morbidity of bilateral CND is significant, and its systematic implementation in the absence on gross nodal involvement requires reassessment.

Increased Mortality and Morbidity Associated With Thyroidectomy for Intrathoracic Goiters Reaching the Carina Tracheae

HYPOTHESIS

Complications associated with thyroidectomy for intrathoracic goiters have been underestimated because of the lack of a precise definition of high-risk patients.

DESIGN

Retrospective multicenter multinational review of medical records and radiographic images of patients who underwent thyroidectomy for intrathoracic goiters reaching the carina tracheae. Demographic, clinical, operative, anatomical, and pathological data were recorded.

RESULTS

There were 35 patients (mean +/- SE age, 63 +/- 11 years) included in the study. In 4 patients, the goiter was asymptomatic; 10 patients had dysphagia, 24 patients had dyspnea, and 3 patients had superior vena cava syndrome. A median sternotomy was required in 12 patients and a right-sided thoracotomy in 1 patient. The mean +/- SE operative time was 145 +/- 72 minutes (range, 50-360 minutes). Transient hypoparathyroidism developed in 13 patients. Four patients experienced transient hoarseness, and 1 patient had permanent vocal cord paralysis. There were no significant differences between the proportion of patients who underwent or did not undergo sternotomy or thoracotomy regarding vocal cord dysfunction (2 [15%] of 13 patients vs 3 [13%] of 22 patients) or hypoparathyroidism (5 [38%] of 13 vs 6 [28%] of 22 patients). The mean postoperative hospital stay was 10 days (range, 2-84 days). Four patients required reoperation. Two patients died. Nine of 14 patients with thyroid glands weighing at least 260 g required sternotomy vs 3 of 14 patients with thyroid glands weighing less than 260 g (P = .02). Overall, 18 [52%] of 35 patients were discharged without any complication.

CONCLUSION

Intrathoracic goiters reaching the carina tracheae carry a high unreported risk of sternotomy, postoperative complications, reoperation, and death.

Bone Mineral Density in Menopausal Women with Primary Hyperparathyroidism before and after Parathyroidectomy

The relationship between osteoporosis and primary hyperparathyroidism (pHPT) has not been definitely established because both diseases occur predominantly in postmenopausal women, and because PTH has a paradoxical effect on bone. We have investigated the prevalence of reduced bone mineral density (BMD) in women with pHPT, its relationship with metabolic parameters, and its course after parathyroidectomy. A prospective observational study was carried out on perimenopausal and postmenopausal women consecutively diagnosed and operated on for pHPT. Demographic data were recorded, as well as, PTH, Ca, calciuria/24h, P, vitamin D, adenoma weight. The BMD was measured at three sites: femoral neck (FN), proximal femur (PF), and lumbar spine (LS). Fifty-two patients were included with a mean age of 61+/-12 years. The prevalence of reduced BMD (< or = 1SD, T-score) was 80%-100% depending on site. Parathyroid hormone was higher in patients with osteoporosis (319+/-181 pg/ml) than in those with osteopenia (230+/-83 pg/ml) or normal BMD (148+/-81 pg/ml;p < 0,04). Twenty-eight patients were investigated 1 year after parathyroidectomy. The BMD improved significantly at all sites, particularly in patients with osteoporosis. Age correlated inversely with BMD increases at the femoral sites (r= -0,47;p = 0,02) but not at the LS. 25-OHD3 plasma levels correlated inversely with BMD increases at PF (r= -0,76; p < 0,0001). In pHPT, there is a high prevalence of BMD abnormalities. No metabolic variables had a definite influence on BMD values but a tendency was observed for lower BMD in severe pHPT. One year after parathyroidectomy, there were significant BMD increases that were more marked at femoral sites, in younger patients, in patients with preoperative osteoporosis, and in those with lower plasma levels of 25-OHD3.

Prevalence of long-term upper aerodigestive symptoms after uncomplicated bilateral thyroidectomy

BACKGROUND

Subjective nonspecific upper aerodigestive symptoms (UADS) are not uncommon after thyroidectomy. Their type, duration, and prevalence, however, have not been investigated in a controlled design. The objective of this study was to investigate the prevalence of UADS after thyroidectomy.

METHODS

A consecutive cohort of 60 patients who had undergone uncomplicated total (n = 38) or near total (n = 22) thyroidectomy were investigated retrospectively at a mean of 4 years after surgery. An independent unblinded researcher interviewed each patient and asked for the presence or frequency of voice changes, cough, dysphagia, neck strangling, and annual incidence of common colds, before and after thyroidectomy. Sixty patients, matched for age, sex, and smoking habits, who had undergone laparoscopic cholecystectomy during the same years served as control subjects.

RESULTS

The prevalence of UADS was similar before thyroidectomy (13%) and cholecystectomy (15%). After operation, UADS had a higher prevalence among thyroidectomized patients: nonspecific voice changes (28% vs 3%), neck strangling (22% vs 0%), and impaired swallowing (15% vs 3%) (P < or = .02 in each). Neck strangling was associated with voice changes and dysphagia (P < or = .03 each).

CONCLUSIONS

Subjective UADS are common long after thyroidectomy. These symptoms may be related to injury to the extrinsic perithyroidal neural plexus innervating the pharyngeal and laryngeal structures.

Postoperative enterococcal infection after treatment of complicated intra-abdominal sepsis

BACKGROUND

The prevalence of enterococcal isolation and factors associated with postoperative enterococcal infection remain ill defined.

METHODS

A prospective longitudinal observational study was conducted of consecutive patients with a first episode of intra-abdominal infection and a positive microbiological culture who did or did not develop a postoperative septic complication involving enterococci. The prevalence of initial enterococcal isolation was determined for each focus of infection. Postoperative enterococcal infections were related to whether appropriate (piperacillin--tazobactam), suboptimal (carbapenems) or inappropriate (cefotaxime plus metronidazole) antienterococcal therapy had been administered empirically.

RESULTS

Enterococci were isolated in 42 (21 per cent) of the 200 patients investigated. The isolation rates were 11 per cent for community-acquired peritonitis, 50 per cent for postoperative peritonitis and 23 per cent for intra-abdominal abscesses of both origins. No enterococci were isolated from 49 patients with perforated appendicitis. Independent factors for postoperative enterococcal infection were type of intra-abdominal infection (P = 0.006), Acute Physiology And Chronic Health Evaluation (APACHE) II score greater than 12 (P = 0.04) and inappropriate empirical antibiotic cover (P = 0.05). Postoperative enterococcal infections were associated with a high mortality rate (21 versus 4 per cent; P < 0.0007).

CONCLUSION

Enterococci are frequently isolated from intra-abdominal infections of non-appendiceal origin and are often involved in postoperative infectious complications, particularly peritonitis. Empirical antibiotic therapy covering Enterococcus faecalis should be contemplated in some circumstances.

Influence of parenteral nutrition on postoperative recovery in an experimental model of peritonitis

BACKGROUND AND AIMS

There seems to be no clear-cut indications for routine TPN support after major elective surgery. The present study was designed to investigate whether TPN could improve the results of standard surgical care for acute peritonitis (laparotomy plus antibiotics).

ANIMALS AND METHODS

Peritonitis was induced in 48 New Zealand rabbits (day -2). On day 0, appendectomy and peritoneal lavage were performed, ceftriaxone (250 mg, i.m./24 h.) was started and animals were randomly assigned to receive regular fluids (RF), glucose-based TPN (G-TPN) or isocaloric fat-based TPN (F-TPN) for 6 days.

MAIN OUTCOME MEASURES

Balance studies (days 1-3), s-albumin, thyroid hormones and urinary catecholamines were determined at various points of the experiment. At postmortem, wound infection, residual intra-abdominal infection and laparotomy wound breaking strength were recorded.

RESULTS

Peritonitis produced a fall in weight, s-albumin and T3. At day 6, weight-loss was more pronounced in RF than in G-TPN or F-TPN (-7 vs 1.5 vs -1.2%;P=0.0001) but s-albumin and T3 concentrations were similar. Diuresis (377 vs 268 vs 269 mL/3 days; P=0.01) was higher and water balance lower (373 vs 511 vs 480 mL/3 days; P=0.01) in Group RF. Although the differences were not statistically significant (P<0.2), persistent infection and wound breaking strength were slightly worse in the pooled TPN groups compared with the RF group (19 vs 6% and 542 vs 701 g, respectively).

CONCLUSIONS

TPN failed to improve relevant biochemical markers and clinical outcome after laparotomy for peritonitis.

Controlling for chance agreement in the validation of medical expert systems with no gold standard: PNEUMON-IA and RENOIR revisited

In the validation of medical expert systems, agreement among different human specialists on a random sample of cases may be taken as a substitute to a missing gold standard. Distance measures between pairs of experts, extensively described in previous studies, do not take into account the influence of chance-expected agreement. A weighted kappa index, with three different weighting schemes, is proposed as an alternative to be applied in the general situation of N cases assessed by E experts about K possible diagnoses, each of them qualified with one of G ordinal categories. A hierarchical cluster analysis, applied to the kappa matrices generated, allows for the classification of the expert system among clinical specialists, providing a relative assessment of its diagnostic ability. The above methodology is applied to the validation of two medical expert systems, PNEUMON-IA and RENOIR.

Learning just-in-time in medical informatics

Just-in-time learning (JITL) methodology has been applied to many areas of knowledge acquisition and dissemination. The paradigm is a challenge to the traditional classroom course-oriented approach with the aim to shorten the learning time, increasing the efficiency of the learning process, improve availability and save money. The information technology tools and platforms have been heavily involved to develop and deliver JITL. This paper discusses the main characteristics of JITL with regard to its implementation to teaching Medical Informatics.

European and Latin-American countries associated in a networked database of outstanding guidelines in unusual clinical cases (ELCANO)

The aim of ELCANO, an EU-funded project, is to build a virtual multilingual multimedia library of unusual clinical cases related to gastroenterology. Based on a standardisation of the format to report and the representation of clinical information on WWW, the multilingual multimedia case has been developed and till now 350 cases have been included. User satisfaction and user acceptance of ELCANO are under evaluation.

IMASIS. A multicenter hospital information system--experience in Barcelona

The present study aimed to analyse physicians' attitudes towards IMASIS, and their potential influence on IMASIS medical record project. IMAS (Institut Municipal d'Assistència Sanitària) is the health care organisation of the City Council of Barcelona. IMAS hospital information system (IMASIS), which first applications were designed and implemented in 1984, is currently facing a new phase, focused on clinical information management. Our approach included a personal interview with representatives of every hospital unit, and a self-administered questionnaire distributed to every clinician. Both provided a worthy insight into the cultural patterns to be considered in the HIS implementation process. Moreover, the results helped to define the subsequent steps of IMASIS evolution. Our experience is proposed as a tool to assess clinical informations systems from a user point of view.

Euthyroid sick syndrome, associated endocrine abnormalities, and outcome in elderly patients undergoing emergency operation

BACKGROUND

Emergency operation in the elderly carries a high risk of death. We investigated the incidence of euthyroid sick syndrome (ESS) and associated nutritional and endocrine abnormalities and their relationship to postoperative outcome in this population.

METHODS

Sixty-six patients older than 70 years of age requiring emergency operations were assessed before any therapeutic intervention. Values for thyroid hormones, catecholamines, cortisol, interleukin-6, interleukin-1, C-reactive protein, and the Acute Physiology and Chronic Health Evaluation II score were determined. Nutritional assessment was carried out. Mortality rates and duration of hospital stay were related to ESS and albumin concentrations.

RESULTS

ESS was diagnosed in 34 patients (51.50%) and was associated with worse Acute Physiology and Chronic Health Evaluation II scores (10.9 vs 8.6; p = 0.004), hypoalbuminemia (34.7 vs 40.8 gm/L; p = 0.0001), lower triceps skinfold (11.8 vs 14.6 mm; p = 0.03), and higher cortisol and norepinephrine levels (937 vs 741 nmol/L [p = 0.04] and 358 vs 250 pg/ml [p = 0.02], respectively), interleukin-6 plasma concentrations (347 vs 113 pg/ml; p = 0.01), death rate (20% vs 0%; p = 0.02), and length of hospital stay (17.2 vs 11.8 days; p = 0.03). A serum albumin level less than 35 gm/L was virtually always associated with ESS.

CONCLUSIONS

ESS is highly prevalent in the elderly with acute surgical problems and is associated with poor nutrition, higher sympathetic response, and worse postoperative outcome. The serum albumin level at admission is a specific marker of ESS.

[Informatics in medical schools and postgraduate education centers for health professionals. Survey on the situation in Spain]

BACKGROUND

Informatics is acquiring an increasing relevance in the medical profession.

METHODS

During the year 1993, a survey was carried out at the medical schools (MS) and postgraduate education centres (PEC) in Epidemiology, Public Health and Health Administration of Spain, on the available computer infrastructure and the teaching activities. The percentages of respondents were 81 at the MS and 100 at the PEC.

RESULTS

81% of the MS and 100% of the PEC had a computer laboratory, mainly equipped with personal computers with MS-DOS operating system. The use of general purpose applications was predominant. The number of students using the computer laboratory was very variable (5-300 per day). 48% of the MS organized courses on microcomputer applications. 66% of the MS included subjects related with informatics in the new curricula.

CONCLUSIONS

Use of computers in the Spanish MS is heterogeneous. Compared with the Nord-American MS, they do not usually use applications of computer-assisted-instruction. The use of the computers at the PEC is much more generalized.

Randomized double-blind placebo-controlled trial of early octreotide in patients with postoperative enterocutaneous fistula

Somatostatin and octreotide both enhance closure of gastrointestinal fistulas. The present trial was undertaken to test whether early combined treatment with parenteral nutrition and octreotide 100 micrograms every 8 h by subcutaneous injection had a beneficial effect compared with parenteral nutrition plus placebo. Thirty-one patients with post-operative gastrointestinal or pancreatic fistula were randomly assigned to receive parenteral nutrition plus octreotide (14 patients) or placebo (17) within 8 days of fistula onset. The percentage reduction in output and rate of spontaneous closure within 20 days were analysed. Mean(s.d.) reduction in output was similar after octreotide and placebo at 24 h (66(43) versus 68(47) per cent, P = 0.9), 48 h (60(46) versus 57(43) per cent, P = 0.8) and 72 h (62(50) versus 66(49) per cent, P = 0.9) after starting the combined treatment. Closure within 20 days was observed in eight of 14 fistulas in patients given octreotide and in six of 17 in those receiving placebo (P = 0.4). Administration of octreotide, within 8 days of fistula onset, associated with parenteral nutrition does not significantly increase the spontaneous fistula closure rate compared with parenteral nutrition plus placebo.

Inadequate levels of metronidazole in subcutaneous fat after standard prophylaxis

The efficacy of antibiotic prophylaxis depends on appropriate tissue levels of the drug being present at the time of potential wound contamination. Metronidazole concentrations in serum, muscle and subcutaneous fat were measured after a single intravenous dose given at two different intervals before operation. Twenty-six patients undergoing abdominal wall procedures were divided into two groups. Patients in group 1 received metronidazole 500 mg intravenously 2 h before surgery, and those in group 2 were given the drug during induction of anaesthesia. Mean plasma levels of metronidazole at the beginning of the procedure were significantly lower (P = 0.01) in group 1 (7.3 (95 per cent confidence interval 5.7-8.9)) micrograms/ml than in group 2 (12.3 (8.9-15.7)) micrograms/ml although in both cases were above the minimum inhibitory concentration for 90 per cent of Bacteroides fragilis. Similar therapeutic concentrations of metronidazole were achieved in plasma and muscle in both groups at the end of the operation. However, patients in both groups had non-therapeutic concentrations of metronidazole in subcutaneous fat: group 1 0.9 (0.6-1.2) micrograms/mg, group 2 1.2 (0.7-1.7) micrograms/mg at the beginning of operation, and 1.2 (0.8-1.6) and 1.5 (0.9-2.1) micrograms/mg respectively at the end of the procedure. It is concluded that infusion of metronidazole 2 h before surgery or during induction of anaesthesia achieved adequate plasma and muscle levels but failed to achieve therapeutic levels in subcutaneous fat.

Influence of nutrition, thyroid hormones, and rectal temperature on in-hospital mortality of elderly patients with acute illness

The present study was undertaken to investigate the interrelation of nutrition, core temperature, and thyroid function and their influence on survival of patients aged > or = 70 y admitted to the hospital with acute conditions. Sixty-seven patients entered the study. Nutritional state, thyroid function, rectal temperature, and the APACHE II score were recorded at admission. The patients were followed until death or hospital discharge. Patients with a serum albumin concentration < 35 g/L showed a lower triiodothyronine (T3) concentration, a higher reverse triiodothyronine (rT3) concentration, and a higher death rate. Prior weight loss (> or = 10%) did not influence thyroid status but increased the mortality rate. Eleven patients were hypothermic (< 36.5 degrees C) and had a higher mortality, lower total T3 concentration, and higher rT3 concentration than the normothermic or hyperthermic subjects. Serum albumin, body weight, and total T3 concentration were higher in survivors (n = 51) than in nonsurvivors (n = 16). Ongoing weight loss and hypoalbuminemia at admission are highly prevalent in elderly people with acute disease, and influence their clinical outcome. Mild hypothermia was a good predictor of death. Hypoalbuminemia and hypothermia were associated with low T3 and high rT3 values.

Validation of the medical expert system RENOIR

RENOIR is an expert system developed to assist the diagnosis of 37 diseases of connective tissue and inflammatory arthropathies. Precise diagnosis of rheumatic diseases implies great uncertainty and there is no gold standard with which to compare the expert system output. To overcome this problem a set of clinical cases was submitted to RENOIR and its diagnoses were compared with those of clinicians. Medical records of 81 patients with rheumatic diseases were interpreted by RENOIR and by 12 clinicians at three different expertise levels in rheumatology. Distances between the likelihoods of the 37 considered diseases provided by clinicians and RENOIR were computed as a disagreement measure. Mahalanobis distance was used to correct the collinearity between the possibilities of each pair of diseases. Using the resulting matrices of distances between experts, cluster analyses were carried out to classify RENOIR among human experts. Greater differences between RENOIR and clinicians than among clinicians themselves were not found.

Influence of calorie source on the physiological response to parenteral nutrition in malnourished rabbits

The present study was designed to investigate whether calorie source influences sodium and water metabolism and sympathetic activity during parenteral nutrition (PN). 20 New Zealand rabbits were starved until a mean weight loss of 18% was achieved and then re-fed for 6 days with 2 formulae of PN with different glucose-fat proportions. In the Glucose group (n = 9), 70% of non-protein calories were given as glucose while in the Lipid group (n = 11), 70% of non-protein calories were administered as lipids. Rabbits with a high glucose intake showed significantly higher weight gain (151 +/- 87 vs. 52 +/- 7 g, P = 0.01), water cumulative balance (542 +/- 132 vs. 411 +/- 87 ml; P = 0.02) and urinary metanephrine excretion (0.42 +/- 0.12 vs. 0.30 +/- 0.1 mumol/d, P = .03). Only in this group, urinary metanephrines correlated positively with water and sodium balances (r2 = 0.6; P = 0.02 and r2 = 0.7; P = 0.009 respectively). The Glucose group showed 2 different responses and in a second experiment 10 additional rabbits were added to this group to allow a statistical analysis of the response pattern: half of the animals increased their extracellular water (ECW) compartment while the remaining animals did not. The former group had higher sodium balance (13.9 +/- 8 vs. 4.3 +/- 5; P = 0.004) and wet lung weight (8.9 +/- 0.9 vs. 7.9 +/- 0.8; P < 0.05) after re-feeding and, at the beginning of PN, their serum aldosterone concentration were also higher (221 +/- 11 vs. 130 +/- 47 pmol/l; P < 0.05). In conclusion, glucose based PN appears to increase sympathetic activity and induce spurious weight gain due to markedly positive wate and sodium balances. Plasma aldosterone concentration at the end of starvation period influences sodium retention and ECW expansion during high glucose re-feeding.

Introducing medical students to medical informatics

Medical informatics (MI) has been introduced to medical students in several countries. Before outlining a course plan it was necessary to conduct a survey on students' computer literacy. A questionnaire was designed for students, focusing on knowledge and previous computer experience. The questions reproduced a similar questionnaire submitted to medical students from North Carolina University in Chapel Hill (NCU). From the results it is clear that although almost 80% of students used computers, less than 30% used general purpose applications, and utilization of computer-aided search of databases or use in the laboratory was exceptional. Men reported more computer experience than women in each area investigated by our questionnaire but this did not appear to be related to academic performance, age or course. Our main objectives when planning an MI course were to give students a general overview of the medical applications of computers and instruct them in the use of computers in future medical practice. As our medical school uses both Apple Macintosh and IBM compatibles, we decided to provide students with basic knowledge of both. The programme was structured with a mix of theoretico-practical lectures and personalized practical sessions in the computer laboratory. As well as providing a basic overview of medical informatics, the course and computer laboratory were intended to encourage other areas of medicine to incorporate the computer into their teaching programmes.

Validation of the medical expert system PNEUMON-IA

The present study validates the expert system PNEUMON-IA. The aim of PNEUMON-IA is assessing the etiology of community-acquired pneumonias from clinical, radiological, and laboratory data obtained at the onset of the disease. Validation was performed using data from medical records of 76 patients with proven clinical diagnosis of pneumonia. The etiological diagnoses provided by PNEUMON-IA were compared to those established by five specialists unrelated to the development of the expert system. For each etiological possibility, both PNEUMON-IA and the experts provided a causal possibility, expressed as a linguistic label (i.e., "almost impossible"). Linguistic labels were then converted to numeric values. In the majority of cases, an etiological diagnosis was unavailable to be used as a gold standard. To overcome this limitation, distances between arrays of etiological possibilities given by specialists and by PNEUMON-IA were considered as an agreement measure between diagnoses. Cluster analysis based on those distances was used to classify PNEUMON-IA among experts. Results showed the same differences between specialists and PNEUMON-IA as among the specialists themselves. The method used to validate PNEUMON-IA could prove useful to assess the performance of expert systems in fields where no gold standard is available.

Long-term effects of parathyroidectomy for primary hyperparathyroidism on arterial hypertension

The prevalence of arterial hypertension in primary hyperparathyroidism (PHPT) is higher than in the general population. With the aim of determining the evolution of hypertension associated with PHPT, we analyzed a group of 56 patients followed for a mean of 60 months (range 10-101 months) after successful parathyroidectomy for PHPT. The study group consisted of 16 men and 40 women. The mean age was 49 +/- 12 years (range 18-73 years). None of the patients had renal impairment. Two hypertensive patients died during the follow-up from complications related to their hypertension. Twelve (21.8%) patients were hypertensive before parathyroid surgery (systolic greater than 160 mmHg and/or diastolic greater than 90 mmHg). Pre-operative midregion serum parathyroid hormone concentration was higher in the hypertensive patients than in normotensive patients (2.7 +/- 2.4 vs 0.82 +/- 0.4 mu iEq/l, p = 0.018). Pre-operative creatinine clearance was lower in the hypertensive patients than in normotensive patients (65.4 +/- 27.5 vs 86.7 +/- 26 ml/min, p = 0.002). There were no significant differences between normotensive and hypertensive patients in age, sex, body weight, clinical manifestations, weight of parathyroid tissue removed, and calcium metabolism, or in plasma concentrations of magnesium, uric acid, cholesterol, proteins, or albumin. During follow-up, none of the patients with pre-operative hypertension became normotensive, whereas 32% of the patients who were normotensive preoperatively developed clinical hypertension. The global prevalence of postoperative hypertension was thus 48%. The patients that developed hypertension after parathyroidectomy were followed for a longer period than the normotensive patients (76 +/- 17 vs 53 +/- 10 months, p = 0.005), had a lower postoperative creatinine clearance (74 +/- 28 vs 90 +/- 25 mg/min, p = 0.07), and higher cholesterol levels (6.2 +/- 1.5 vs 5.5 +/- 0.9 mmol/L, p = 0.08).(ABSTRACT TRUNCATED AT 250 WORDS)

Epidermal growth factor receptors and adenylate cyclase activity in human thyroid tissues

Thyroid stimulating hormone (TSH) and epidermal growth factor (EGF) are growth factors for some thyroid cells in cultures. We have previously found more EGF receptors in neoplastic human thyroid tissues than in normal thyroid tissues. We have also found a higher TSH-stimulated adenylate cyclase (AC) activity in neoplastic human thyroid tissues than in normal thyroid tissues. To clarify the relationship between the effect of EGF and TSH on thyroid tissue, we measured the binding of EGF and TSH and the basal, TSH-stimulated and forskolin-stimulated adenylate cyclase activity in 49 normal, hyperplastic and neoplastic human thyroid tissues (5 normal, 2 Hashimoto thyroiditis, 5 Graves' disease, 14 multinodular goiters, 9 follicular adenomas, 5 follicular carcinomas, 8 papillary carcinomas, and 1 undifferentiated carcinoma). Specific binding of EGF and TSH were measured by radioreceptor assays using competitive inhibition of radio-labeled ligand by unlabeled ligand. Basal, maximally (300 mU/ml) TSH-stimulated, and maximally (100 mM) forskolin-stimulated adenylate cyclase activities were also measured in the same membrane particulate fractions from the thyroid tissues. We found: neoplastic thyroid tissues bind more labeled EGF than nonneoplastic thyroid tissues; follicular adenomas and carcinomas have higher EGF binding than other thyroid tissues; a weak but significant correlation between specific EGF binding and specific TSH binding, and between specific EGF binding and TSH-stimulated adenylate cyclase activity of the thyroid membrane preparations. These findings are consistent with the hypothesis that TSH stimulates an increase in thyroid EGF receptors by increasing intracellular cAMP.(ABSTRACT TRUNCATED AT 250 WORDS)

In vitro bacteriological study of a new hub model for intravascular catheters and infusion equipment

We investigated in vitro the antibacterial properties of a simulated new hub model in which the female part has an antiseptic chamber through which the needle (male part) must pass before connection of the set and the catheter. To establish the time needed for disinfection, the magnitude of reduction of the contaminating inocula by the new hub model, and the antibacterial properties of the different components of the hub, we used needles contaminated with solutions containing high inocula (1.9 x 10(7) to 1.2 x 10(11) CFU/ml) of microorganisms involved in hub-related catheter sepsis. Sterilization of the needles was accomplished by allowing them to remain in the antiseptic chamber for 10 s in all assays with Staphylococcus epidermidis, Pseudomonas aeruginosa, Escherichia coli, and Candida albicans. The rubber closures limiting the antiseptic chamber and the dilution effect of the antiseptic itself accounted for a minor part of the inoculum reduction achieved by the new hub model. This simulated hub provides good protection against endoluminal contamination. Further studies seem warranted to prove its industrial viability and clinical efficacy.

A new experimental model for secondary hyperparathyroidism

We have developed an animal model to study the pathogenesis of secondary hyperparathyroidism by inducing stable uremia in Sprague-Dawley rats by selective microligation of terminal branches of the left renal artery, followed by right nephrectomy. After 4 weeks the animals were killed, the parathyroid glands were removed and weighed, and blood samples were obtained. Of 30 rats, uremia developed in 22 (73%; uremic group) and eight (27%) died or did not become uremic. A sham-operated group of 15 rats served as control (control group). Creatinine levels were 1.8 +/- 0.5 mg/dl in the uremic group versus 0.5 +/- 0.1 mg/dl in the control group (p less than 0.0001). Parathyroid glands were hyperplastic in all rats with uremia and were heavier than parathyroid glands of control animals (70.3 +/- 26 vs 19.1 +/- 8 micrograms; p less than 0.0001). In the group with uremia, parathyroid hormone levels were increased over those of the control group (112.6 +/- 13 vs 28.9 +/- 6.2 pg/ml; p less than 0.0001), whereas osteocalcin levels were similar (36.6 +/- 11 vs 37.5 +/- 1 ng/ml). Serum calcium, phosphate, and alkaline phosphatase levels were similar in both groups. Our model can be used to test hypotheses concerning the treatment of secondary hyperparathyroidism and the relative pathogenetic relevance of vitamin D deficiency and phosphate retention.

Medullary thyroid carcinoma. The need for early diagnosis and total thyroidectomy

Forty patients with medullary thyroid carcinoma and 3 patients with C-cell hyperplasia were studied. Seventeen (40%) cases were sporadic and 26 (60%) were hereditary. Eight patients had type lla multiple endocrine neoplasia, 7 patients had type llb multiple endocrine neoplasia, and 11 patients had familial nonmultiple endocrine neoplasia medullary thyroid carcinoma. Mean follow-up was 6.3 years, with actuarial survival of 88% and 78% at 5 and 10 years (22 and 13 patients), respectively. Seven patients died 1.5 to 10 years after the initial operation; all had advanced disease at presentation (6 with distant, 1 with lymph node metastasis). No deaths occurred in patients with familial nonmultiple endocrine neoplasia medullary thyroid carcinoma, C-cell hyperplasia, or medullary thyroid carcinoma limited to the thyroid gland. Nineteen (68%) of 28 patients diagnosed without screening had regional or distant metastases, whereas only 6 (40%) of 15 patients diagnosed by screening had metastases. Twenty-six patients treated initially with total thyroidectomy and central neck clearance required an average of one reoperation, whereas those with lesser initial procedures required an average of two reoperations. We concluded that (1) familial nonmultiple endocrine neoplasia medullary thyroid carcinoma, early medullary thyroid carcinoma or C-cell hyperplasia, and asymptomatic patients have a good prognosis; (2) screening for medullary thyroid carcinoma by measuring serum calcitonin levels results in earlier diagnosis; and (3) total thyroidectomy and central neck clearance is the procedure of choice for medullary thyroid carcinoma.

Measurement of body water compartments after ligation of the common bile duct in the rabbit

To elucidate the pathogenesis of renal insufficiency associated with obstructive jaundice we have studied spontaneous water intake and body water compartments in rabbits undergoing common bile duct ligation. Total body water, extracellular water and plasma volume were measured by multi-isotope dilution technique. During the initial 6 postoperative days spontaneous water intake was 898 ml in sham operated animals (SO) but only 280 ml in jaundiced rabbits (OJ6) (P less than 0.01). Creatinine clearance was almost unchanged in SO but fell to 60 per cent of the preoperative values both in OJ6 and in paired-drink sham operated animals (SO2). There was a 15 per cent decrease in total body water (P less than 0.01) and a 24 per cent decrease in extracellular water (P less than 0.01) 6 days after bile duct ligation. There was a further reduction of the extracellular water to 35 per cent and a 15 per cent reduction of plasma volume 12 days after ligation. Water restriction mimicked the alterations in body composition produced by bile duct ligation. We conclude that bile duct ligation is associated with hypodypsia and a depletion of extracellular water and plasma volume. These alterations could explain the tendency to develop hypotension and renal failure which are associated with obstructive jaundice.

A randomized trial on the effect of mannitol on postoperative renal function in patients with obstructive jaundice

A randomized trial was undertaken to reassess the effectiveness of mannitol in preventing postoperative renal impairment in patients with obstructive jaundice. The study included 31 patients with obstructive jaundice (bilirubin, 3 mg/dl or higher) randomly allocated in two groups to receive (n = 17) or not receive (n = 14) preoperative mannitol. Sixty-five percent of patients had a creatinine clearance below 70 ml/min before surgery. Serum bilirubin and bacteribilia had no relation with preoperative renal function. No relation was found between serum bilirubin value and the percentage fall in postoperative creatinine clearance. Compared with the preoperative values, the postoperative creatinine clearance was significantly impaired in the mannitol group (p = 0.03) and remained almost unaltered in the no-mannitol group. Three patients (9.7%) died of acute renal failure; two were in the mannitol group and one was in the no-mannitol group. Serum fibrin degradation products were not sensitive markers for impending renal failure. There was no significant difference in postoperative serum sodium concentration or in the urinary sodium excretion. Administration of mannitol did not improve the postoperative renal function of jaundiced patients, nor did it prove beneficial in preventing renal failure. Our results suggest that severe disturbances of body-fluid compartments may be the basic mechanism underlying kidney dysfunction in obstructive jaundice and that further water depletion induced by mannitol may indeed prove detrimental.

Parathyroid localization. Clinical review

Recent advances in the techniques of preoperative parathyroid localization include ultrasonography, computed tomography, thallium-technetium subtraction scanning, magnetic resonance imaging, digital subtraction angiography with selective venous catheterization for PTH measurement, and ultrasound or CT-guided needle aspiration biopsy for cytological examination or PTH assay. These techniques are helpful for patients with hyperparathyroidism undergoing the initial operation, and essential for patients with persistent or recurrent hyperparathyroidism undergoing reoperation. Noninvasive procedures should be performed first, and the combination of any two positive studies localizes the tumor with near certainty. Invasive procedures have a higher risk of complications and are recommended only in selected patients before reoperation.

Epidermal growth factor receptors in parathyroid tumors

Hyperparathyroidism is caused by parathyroid adenomas, hyperplastic parathyroid glands, or rarely parathyroid carcinoma. Membrane receptors to epidermal growth factor (EGF), a growth-stimulating polypeptide, have been shown in other endocrine tissues such as thyroid, breast, and ovary, but not in parathyroid glands. Therefore we studied abnormal parathyroid glands from fourteen patients for the presence of EGF receptors. The binding of radioiodine-labeled EGF to the crude membrane fractions was studied using competitive inhibition with unlabeled EGF. In ten patients with solitary parathyroid adenomas, seven adenomas had no EGF binding, three had low affinity EGF binding with dissociation constants (Kd) of 28 to 148 nM and maximal specific binding (Bmax) of 285 to 1944 fmole/mg protein. In two patients with multiple adenomas, a high affinity EGF binding with Kd of 0.28 to 2.8 nM and Bmax of 6.7 to 43 fmole/mg protein was found. In one patient with hyperplastic parathyroid glands secondary to renal failure, a high affinity EGF binding with Kd of 1.7 nM and Bmax of 18 fmole/mg protein was found. In one patient with persistent hyperparathyroidism following a successful renal transplant (tertiary hyperparathyroidism), a low affinity EGF binding with Kd of 25 nM and Bmax of 219 fmole/mg protein was found. The binding of EGF did not correlate with the preoperative serum calcium or PTH levels. Thus, hyperplastic parathyroid glands (either primary or secondary) have high affinity EGF receptors whereas solitary parathyroid adenomas do not.