Assessment of hospital surge capacity using the MACSIM simulation system: a pilot study.

AIM: The aim of this study was to use a simulation model developed for the scientific evaluation of methodology in disaster medicine to test surge capacity (SC) in a major hospital responding to a simulated major incident with a scenario copied from a real incident. METHODS: The tested hospital was illustrated on a system of magnetic boards, where available resources, staff, and patients treated in the hospital at the time of the test were illustrated. Casualties were illustrated with simulation cards supplying all data required to determine procedures for diagnosis and treatment, which all were connected to real consumption of time and resources. RESULTS: The first capacity-limiting factor was the number of resuscitation teams that could work parallel in the emergency department (ED). This made it necessary to refer severely injured to other hospitals. At this time, surgery (OR) and intensive care (ICU) had considerable remaining capacity. Thus, the reception of casualties could be restarted when the ED had been cleared. The next limiting factor was lack of ventilators in the ICU, which permanently set the limit for SC. At this time, there was still residual OR capacity. With access to more ventilators, the full surgical capacity of the hospital could have been utilized. CONCLUSIONS: The tested model was evaluated as an accurate tool to determine SC. The results illustrate that SC cannot be determined by testing one single function in the hospital, since all functions interact with each other and different functions can be identified as limiting factors at different times during the response.

Development and evaluation of a new simulation model for interactive training of the medical response to major incidents and disasters.

BACKGROUND AND AIMS: The need for and benefit of simulation models for interactive training of the response to major incidents and disasters has been increasingly recognized during recent years. One of the advantages with such models is that all components of the chain of response can be trained simultaneously. This includes the important communication/coordination between different units, which has been reported as the most common cause of failure. Very few of the presently available simulation models have been suitable for the simultaneous training of decision-making on all levels of the response. In this study, a new simulation model, originally developed for the scientific evaluation of methodology, was adapted to and developed for the postgraduate courses in Medical Response to Major Incidents (MRMI) organized under the auspices of the European Society for Trauma and Emergency Surgery (ESTES). The aim of the present study was to describe this development process, the model it resulted in, and the evaluation of this model. METHODS: The simulation model was based on casualty cards giving all information normally available for the triage and primary management of traumatized patients. The condition of the patients could be changed by the instructor according to the time passed since the time of injury and treatments performed. Priority of the casualties as well as given treatments could be indicated on the cards by movable markers, which also gave the time required for every treatment. The exercises were run with real consumption of time and resources for all measures performed. The magnetized cards were moved by the trainees through the scene, through the transport lines, and through the hospitals where all functions were trained. For every patient was given the definitive diagnosis and the times within certain treatments had to be done to avoid preventable mortality and complications, which could be related to trauma-scores. RESULTS: The methodology was tested in nine MRMI courses with a total of 470 participants. Based on continuous evaluations and accumulated experience, the setup of the simulation was step-wise adjusted to the present model, including also collaborating agencies such as fire and rescue services as well as the police, both on-scene and on superior command levels. The accuracy of the simulation cards for this purpose was evaluated as "very good" by 63 % of the trainees and as "good" by 33 %, the highest two of the six given alternatives. The participants' ranking of the extent that the course increased their competencies related to the given objectives on a 1-5 scale for prehospital staff had an average value of 4.25 ± 0.77 and that for hospital staff had an average value of 4.25 ± 0.72. The accuracy of the course for the training of major incident response on a 1-5 scale by prehospital staff was evaluated as 4.35 ± 0.73 and that by hospital staff as 4.30 ± 0.74. CONCLUSIONS: The simulation system tested in this study could, with adjustments based on accumulated experience and evaluations, be developed into a tool for the training of major incident response meeting the specific demands on such training based on recent experiences from major incidents and disasters. Experienced trainees in several courses evaluated the methodology to be accurate for this training, markedly increasing their perceived knowledge and skills in fields of importance for a successful outcome of the response to a major incident.

Future of thyroid surgery and training surgeons to meet the expectations of 2000 and beyond.

What is the future of thyroid surgery in the new millennium? How can surgeons keep abreast of advances in thyroid endocrinology, genetics, surgical therapy, and other aspects of thyroid disease management? How should surgeons be trained to become highly competent in thyroid disease and to perform safe, effective thyroid operative procedures? Nine internationally recognized endocrine surgeons were asked to express their views on these and related subjects. They noted that advances in molecular biology, pathology, and genetics of thyroid disease should allow more tailored surgical approaches during the twenty-first century. Current training of general surgical residents in thyroid and other types of endocrine surgery is highly variable, which may contribute to increased complication rates and number of second operations. The leadership for addressing these deficiencies and promoting a more organized approach to thyroid disease management should come from national endocrine surgery associations and their leaders. It is incumbent upon endocrine surgeons to maintain their central role in the management of many aspects of thyroid disease. Organizing teams of specialists into thyroid centers (centers of excellence) can (1) increase efficiency; (2) increase quality of care; (3) decrease costs; (4) encourage a more individualized approach to surgery; (5) lower complication rates; and (6) foster innovation in technology and disease management. Two years of additional fellowship training in thyroid and endocrine surgery is now being advocated by increasing numbers of national endocrine surgical associations as the best way to prepare surgeons for society's needs for highly skilled, competent thyroid surgeons of the future.

Effects of inhalation of corticosteroids immediately after experimental chlorine gas lung injury.

BACKGROUND: To assess the effects of treatment with nebulized corticosteroids immediately after chlorine gas injury. METHODS: Eighteen anesthetized and mechanically ventilated pigs were exposed to chlorine gas (140 ppm for 10 minutes) and observed for 6 hours. Nine pigs were treated with nebulized beclomethasone-dipropionate 20 microg/kg (BDP group), and nine pigs were given no treatment (control group). RESULTS: All animals developed severe pulmonary dysfunction. The initial decrease in PaO2 was similar in both groups, but BDP-treated animals improved whereas control animals deteriorated (p < 0.005; analysis of variance). Pulmonary vascular resistance increased in both groups but less in the BDP group (p < 0.01). Lung-thorax compliance was better preserved in the BDP group (p < 0.01), and oxygen delivery was significantly better in the BDP group (p < 0.01). One animal died in the BDP group, as did three animals in the control group. CONCLUSION: Immediate treatment with nebulized BDP improved pulmonary and cardiovascular function after experimental chlorine gas injury.

Pulmonary dynamics of radiolabelled erythrocytes and leucocytes in early gram-negative sepsis in pigs.

OBJECTIVE: To study the pulmonary dynamics of erythrocytes and leucocytes in vivo in early experimental sepsis. DESIGN: Open, experimental study. SETTING: Academic research laboratory, Sweden. MATERIAL: 10 adolescent domestic pigs. INTERVENTIONS: Technetium (99mTc) labelling of erythrocytes (n = 5), and indium (111In) labelling of autologous leucocytes (n = 10). Sepsis was induced by endotoxin (n = 4) or live Escherichia coli (n = 3), given intravenously. MAJOR OUTCOME MEASURES: Regional pulmonary scintigraphy, central haemodynamics, and gas exchange followed for 180 minutes. RESULTS: Septic animals developed arterial hypoxia, pulmonary hypertension, and systemic hypotension. They also had an early increase in mean (SD) regional pulmonary erythrocyte and leucocyte counts [+10.3 (7.7)% and +12.0 (3.5)%, respectively] with a simultaneous maximum 27-32 minutes after the start of the septic insult. CONCLUSIONS: The immediate sepsis-induced pulmonary accumulation of leucocytes as detected by external scintigraphy can be ascribed at least in part to a simultaneous sepsis-induced increase in pulmonary blood volume.

Value of serum thyroglobulin measurement in patients operating on for well differentiated thyroid carcinoma.

OBJECTIVE: To study the clinical relevance of measurements of serum thyroglobulin in patients undergoing total thyroidectomy for well differentiated thyroid cancer. DESIGN: Prospective study. SETTING: University hospital, Sweden. SUBJECTS: 194 patients operated on for well differentiated thyroid cancer from 1 January 1978 to 31 December 1992. INTERVENTIONS: All patients underwent total thyroidectomy by a standard technique, and were prospectively followed up at regular intervals by clinical examination and measurement of the serum thyroglobulin concentration. RESULTS: Six patients whose thyroglobulin concentrations after operation were low or undetectable had gradual increases leading to detection of recurrences that could be treated successfully. Six patients had gradual increases without detectable recurrences. In 12 patients thyroglobulin concentrations remained high after operation with no signs of thyroid tissue remaining, which we interpreted as persistence of the disease. No recurrence was found without an appreciable rise in the thyroglobulin concentration. Thyroglobulin antibodies were found in 81 (42%). CONCLUSION: Measurement of the serum thyroglobulin concentration is a valuable addition to the follow up of patients operated on for highly differentiated thyroid cancer. In many cases it is the first sign of recurrent disease, thereby facilitating early and successful treatment.

Heparin ameliorates pulmonary hypertension induced by platelet-activating factor in pigs.

The purpose of this study was to investigate the effects of heparin on the haemodynamic changes which were induced by platelet-activating factor in the pulmonary and systemic circulation in pigs. Mean arterial pressure and mean pulmonary arterial pressure were measured continuously in five anaesthetised juvenile pigs. Bolus doses of platelet-activating factor (0.2-2 microg) were given intravenously to establish a dose response curve. Heparin (300 units/kg) was given intravenously. Thirty minutes later, the same doses of platelet-activating factor were repeated to establish a second dose response curve. Platelet-activating factor caused a dose dependent pulmonary artery hypertension, associated with an initial systemic hypotension followed by systemic hypertension. Heparin effectively reduced the low dose (0.2 microg) platelet-activating factor-induced pulmonary arterial hypertension (p<0.01) but not the higher doses. It had no effect on the platelet-activating factor-induced systemic hypotension or hypertension. The pulmonary and systemic circulation responded differently to platelet-activating factor after giving heparin. While heparin ameliorated the platelet-activating factor-induced pulmonary hypertension, it did not affect the changes in the systemic circulation.

Exposure to chlorine gas: effects on pulmonary function and morphology in anaesthetised and mechanically ventilated pigs.

We have examined the effects of chlorine gas inhalation (110 and 140 ppm) on cardiovascular and pulmonary function in nine anaesthetised and mechanically ventilated pigs. Four additional pigs, which were similarly treated but not exposed to gas, served as controls. Severe pulmonary dysfunction developed when the animals were exposed to 100 l of 140 ppm chlorine gas for 10 min. Five of six animals died within 6 h of exposure. This dose induced a rapid drop in arterial oxygen tension (P < 0.001 compared with controls, ANOVA), a biphasic decline in lung compliance (P < 0.001) and a gradual increase in pulmonary vascular resistance (P < 0.001) that eventually caused a significant reduction in cardiac output (P < 0.05). Microscopic examination showed sloughing of the bronchial epithelium and early infiltration with leukocytes, but largely intact alveoli. The sequence of events and the microscopic appearance suggested that the initial stage of pulmonary dysfunction (the first 1 or 2 h) was the result of mismatching of ventilation and perfusion. This was followed at a later stage by interstitial oedema and migration of immunocompetent cells into the tissue. We conclude that exposure to 100 l of 140 ppm chlorine gas induces a severe stereotypic lung injury with high mortality within 6 h in this anaesthetised animal model.

Tall-cell variant of papillary thyroid cancer: disregarded entity?

The tall-cell variant of papillary thyroid carcinoma (TCV) has been described as an aggressive tumor with a significantly higher incidence of recurrence and mortality than other forms of papillary carcinoma. In some series it has accounted for up to 10%, whereas in other series it has not been reported at all, indicating that there are difficulties identifying it. In a series of 162 consecutively treated patients with papillary thyroid carcinoma treated by total thyroidectomy according to a highly standardized procedure, all specimens were specifically examined by an international group of pathologists to establish the occurrence of TCV. All patients with TCV were studied with regard to local aggressiveness, the presence of metastases, iodine uptake, DNA pattern, thyroglobulin production, treatment (surgical and adjuvant), and outcome (follow-up 3-17 years, median 10 years). At primary histopathologic evaluation by the local pathologist, three patients were recorded as having TCV. At special evaluation by the expert group, eight more cases were found, giving a total of 11 patients in this series (7%). Five of them had extracapsular growth, and four were multifocal. Three had metastases at the time of admission. Seven tumors were diploid, one tetraploid, and three aneuploid. Of the three patients with primary distant metastases two died (8 and 24 months after operation), and one is still alive after 10 years. Four other patients developed recurrences, one of whom died from cardiac failure, but the others have so far been treated successfully. Two of these recurrences had no radioiodine uptake, and one had no rise in thyroglobulin concentrations; the other two had rising values that correlated with recurrence. The other four patients are alive without recurrence. It was concluded that identification of the TCV requires examination by an experienced pathologist. Moreover, it may have a higher incidence than is generally recognized. No reliable criteria for prognostic classification were identified. The results suggest that early identification and active treatment can lead to an outcome more favorable than has previously been described.

Role of platelet-activating factor on cardiovascular dysfunction in postischemic shock in pigs.

This study aimed at evaluating the role of platelet-activating factor (PAF) on cardiovascular dysfunction in postischemic shock in pigs. Sixteen pigs were randomly allocated to two groups of eight each. Their aorta was clamped above the celiac axis for 45 min and then declamped. The animals were studied for 2 h after declamping. They were given a continuous infusion of Hartmann's solution 6.75 ml/kg/h throughout the experiment. The experimental group was given a potent specific PAF receptor antagonist 15 min before reperfusion (BB-882 1 mg/kg bolus followed by continuous infusion of 1 mg/ kg/h till the end of the experiment). The control group was given vehicle instead. Reperfusion in the control group caused prolonged hypotension (mean arterial pressure (SEM): 29 (1) mm Hg, immediately after declamping, compared with 74 (3) at baseline), an increase in pulmonary vascular resistance (491.6 (51.5) dyn.s.cm-5, 2 h after declamping, compared with 274.2 (19.4) dyn.s.cm-5 at baseline), a reduction in cardiac output (1.75 (0.15) liters/min, 2 h after declamping, compared with 2.8 (0.21) liters/min at baseline), hyperglycemia (13.7 (0.8) mmol/l, immediately after declamping, compared with 6.26 (0.6) mmol/l at baseline), and lactic acidemia (11.28 (0.5) mmol/l, immediately after declamping, compared with 4.55 (0.67) mmol/l at baseline). BB-882 did not improve any of these variables. PAF does not play a major role on cardiovascular dysfunction in postischemic shock in pigs.

Overexpression of p53 in tall cell variants of papillary thyroid carcinoma.

BACKGROUND: The tall cell variant (TCV) is a clinically aggressive subtype of papillary thyroid cancer. The aim of this study was to discover the prevalence of mutant forms of p53 protein in this subtype and relate it to clinical outcome. METHODS: Eighteen patients with TCV and a control group with common papillary cancers, matched for age and gender, were studied. The p53 mutations were identified by means of immunohistochemical staining. Data reviewed were overall survival, recurrence, TNM stage, and p53 positivity. RESULTS: p53 mutations occurred in 11 (61%) patients with TCV compared with two (11%) in control group (p = 0.05). In the TCV group two patients died of the disease (11%) and eight (44%) had local recurrences or distant metastases compared with none in the control group. All deaths and 70% of the recurrences occurred in patients with stage III or IV disease. p53 positivity did not correlate with any reduction in survival (7% compared with 9%) but with increased rate of local (23% compared with 4%) and distant (23% compared with 13%) recurrences. CONCLUSIONS: TCV was associated with a significantly higher rate of p53 positivity than common papillary carcinoma. The stage of the disease seemed to be a better prognostic indicator than p53 positivity for overall survival.