Three years' experience with computer-based intensive care of patients following open heart and major vascular surgery

The authors present their experiences with the Roche-5000 Computer-Based Intensive Care System in the management of 100 consecutive patients who have undergone open heart or major vascular surgery. The system performs the following junctions: (1) numerical and graphic display, out-of-limits alarms, storage and printout of 12 biological and surgical parameters, including chest drainage and urine output, by on-line direct monitoring; (2) display, storage, and printout of all additional laboratory and clinical data by manual input; (3) automatic demand-regulated transfusion and infusion program; (4) a program of medical logic, which includes situation analysis based on the above, two way dialogue with the computer, treatment recommendations to the physician, selective nursing and laboratory orders, acid-base analysis, and instructions for respirator setting. It was found that the computer-monitored patients recovered faster and smoother, with fewer fluctuations in the measured parameters and fewer postoperative complications than did those treated by conventional methods. One additional important effect of the system was that the nurse, relieved of the mechanical tasks of measuring, charting, and recording, was left with a greater amount of time for the care of the patient's personal needs. It seems ironic that such a technical advancement in electronics not only made the recovery faster and safer but also created a more humanistic approach in patient care, through better application of basic nursing techniques.     

Urological history-taking and management recommendations by microcomputer

A system has been developed to acquire a complete urological history using an Apple microcomputer. The system can ask up to 300 multiple choice questions which the patient answers using a light pen. The questions are grouped into blocks for urological symptoms and complicating factors. A printout summarises the history and the recommended further investigations. A copy of this is given to the patient and the referring doctor. The clinician discusses the printout and proposed investigations with the patient. The system has been tested against experienced clinicians and the results are presented. The computer system was evaluated for 26 patients and was found to record all of the important information. The system is now in regular use in the out-patient clinic as the first part of the diagnostic work-up in suitable referrals. This system has shortened waiting times for first appointments. To date 261 patients have used the system. The consultant urologist continues his practice of reading all referral letters and allocating priorities. Conditions requiring immediate physical examination (e.g. testicular swelling) are not suitable for this type of approach.     

Twenty-four-hour monitoring of esophagopharyngeal pH in outpatients. Use of four-channel pH probe and computerized system

A 24 hour computerized four-channel esophagopharyngeal pH system is described. Using a 1.5 mm diameter esophageal probe containing four separate antimony-tipped electrodes and a small patient-worn digital recording computer, inpatient and outpatient studies are performed in the physiologic environment of the patient's workplace or home. Stored pH data in the computer are teletransmitted from satellite esophageal pH laboratories to a central esophageal pH laboratory for analysis, scoring, printout, and storage. Satellite laboratories located in hospitals, clinics, and physicians' offices use a minimum of equipment and obtain a quality computer-based printout. This preserves patient-physician relationships in the home environment and is cost-effective. Four case reports are presented identifying the advantages derived from the four-channel system localizing and quantifying the extent of cephalad transport of refluxed upper gastrointestinal content. The system has unique clinical and research potential in all age groups in such disparate problems as sleep apnea, laryngitis, bradycardia and cardiac irregularities, and aspiration pneumonia and pulmonary abscess.     

A new comprehensive anaesthetic record

Eternal vigilance and strict attention to detail are the 'sine qua non' of safe anaesthesia with the contemporaneous anaesthetic record being the documentation. As an alternative to the manifold and often inadequate forms currently in use, a new rapidly completed anaesthetic record incorporating a comprehensive checklist is presented. Guidelines of the Faculty of Anaesthetists, Royal Australasian College of Surgeons are met. It is argued that the chart improves safety not only by its direction to attention during the peroperative visit and equipment check, but also by its demand for the ongoing attention of the anaesthetist. Reservations are expressed about 'black box' recording by trend printout and a perspective for computerised and automated anaesthetic records is also discussed.     

Computerised triage in a prostate assessment clinic

An MS Office package has been developed to score IPSS, take a patient history, compare flows with nomograms and decide on interim management. This is based on these scores, residual volume and laboratory results. A clearly formatted GP letter is produced. The patient uses a touch screen to answer questions on the IPSS and other medical history. These questions and responses are stored in Excel spread sheets. Clinic staff then enter results of flow studies, urinalysis, U&E and PSA. Excel Visual Basic creates a detailed printout for the notes and the MS Office mail merge facility creates a summary printout, which also serves as a letter to the GP. Excel allows embedding of formulae and program code to implement the rules for management. Based on these rules, the program either generates a request for an urgent appointment in the clinic or recommends the use of either an alpha blocker (if not contraindicated by medical history) or 5 alpha reductase inhibitors in the interim period before they are reviewed in clinic. A total of 139 patients have been seen and the computer decisions compared with those of a consultant urologist. Agreement was found in 106, disagreement in 33. However, 21 of the 33 involved computer oversensitivity to flow results. We do not anticipate difficulty improving this and are investigating using an artificial neural network. Of the other 12 patients, the urologist departed from the fixed rules for IPSS, creatinine, PSA and residual urine when only one variable was slightly abnormal. To conclude, this novel user-friendly system shows great potential in the management of prostate outpatients. Some tuning is needed, with particular respect to uroflow results.     

Use of computer technology in training assistants in the anesthesia department

The growing importance of computer technology in the fields of medical diagnosis and monitoring cannot be disputed. Few studies, however, have investigated the usefulness of computers in medical education. The following paper presents a teaching program for novice anaesthesists which helps demonstrate the problem of anaesthetizing high risk patients and conveys general guidelines for preoperative diagnosis and intraoperative monitoring. All data registered can be displayed on several video screens simultaneously. A printout of the guidelines is also available. Initial impressions of the program are presented.     

Computerized urological history taking: Its development and application in an open access Incontinence Resource Center

A computer system has been developed to take a full urological history including incontinence. The development and eventual implementation on IBM-compatible machines is described. Patients answer questions with a light pen and in this way the history is built up. A printout is produced with the history and recommendations for initial investigations. Contraindications to investigations are highlighted and warnings generated. Over 600 patients have used the urology program to their satisfaction and that of the referring doctor. The computer does not replace the clinician but allows better use of the specialist's time with the patient to fine tune the history and assess the individual's attitude, perception, and concerns. The system uses a database package to facilitate development.Having been impressed by the high level of acceptance and quality of information, we have introduced a modified system custom-designed to serve our open access Incontinence Resource Center.     

Epinephrine test dose in children: is it interpretable on ECG monitor?

Background:  Epidural and other regional blocks are performed in children under general anesthesia; the response to a 'test dose' may be altered during administration of general anesthetics. Limited data is available describing changes in electrocardiogram, blood pressure and heart rate (HR) following unintentional intravascular injection of a lidocaine–epinephrine-containing test dose, under sevoflurane anesthesia in children.
Methods:  Sixty-eight children undergoing elective surgeries under sevoflurane anesthesia were administered 0.1 ml·kg⁻¹ of 1% lidocaine with epinephrine 0.5 μg·kg⁻¹ or normal saline intravenously, to simulate an accidental intravascular test dose. T-wave changes in lead II on the anesthesia monitor and on a printed ECG were noted over the initial 1 min as well as changes in HR and systolic blood pressure (SBP) over an initial 3 min period.
Results:  Following injection of lidocaine–epinephrine, a significant increase in T-wave amplitude in lead II was noted in 91% of children on the ECG monitor and in 94% of children on the ECG printout of the same lead. In 64% of children, an increase in HR of ≥10 b·min⁻¹ and in 76% of children an increase in SBP of ≥15 mmHg was noted.
Conclusion:  An increase in T-wave amplitude can easily be detected by carefully observing the ECG monitor or an ECG printout within a minute following the accidental i.v. administration of 0.1 ml·kg⁻¹ of 1% lidocaine-epinephrine (0.5 μg·kg⁻¹) regional anesthetic test dose in children under sevoflurane anesthesia.     

Value of intraoperative image intensifier prints in trauma surgery.

We have studied the use of image intensification in a trauma theatre over a period of 6 months with particular reference to the acquisition of intraoperative image intensifier thermal prints instead of formal radiographs. The quality of the prints and the savings generated have been assessed. During the study period, 476 patients underwent orthopaedic trauma procedures. The image intensifier was used for intraoperative screening in 280 patients. In 278 of these a thermal print was obtained. This was used, instead of formal check radiographs, to plan further management in 210 patients (75%). In 68 patients, the printout was insufficient in its coverage of the operated area, and a check radiograph was also obtained. In no case did the clarity of the thermal image hinder accurate interpretation. We believe that thermal images are a useful substitute for formal postoperative radiographs in many trauma cases, and that, with notable exceptions, their use could decrease costs, reduce patient discomfort and radiation dose and spare overloaded radiology services.     

Accuracy of an intelligent CPAP machine with in-built diagnostic abilities in detecting apnoeas: a comparison with polysomnography.

BACKGROUND--In patients with sleep apnoea early diagnostic evaluation and treatment may be delayed due to limited access to full polysomnography (PSG). For "typical" patients, simplified strategies are needed. A study was performed to evaluate the accuracy of a new continuous positive airway pressure (CPAP) device with in-built diagnostic abilities (Autoset) in detecting apnoeas. METHODS--Twenty seven patients underwent full overnight polysomnography. Data with the Autoset were acquired simultaneously. Standard nasal prongs were used. Apnoeas were detected by special analysis of the flow signal. As the Autoset derives all its data from one signal, careful examination of the raw data is important to assess the quality of the flow signal. RESULTS--There was a correlation between the apnoea index (AI) assessed by the Autoset (AI-Autoset) and by polysomnography AI-PSG (r = 0.85) and between the AI-Autoset and the apnoea/hypopnoea index (AHI) during polysomnography (r = 0.87). The Autoset identified patients with an AHI-PSG of > 20 (a level of respiratory disturbance that would warrant consideration for treatment in most centres for sleep disorders) with a sensitivity of 82% and a specificity of 90%. CONCLUSIONS--The good correlation between the apnoea index measured by the Autoset and by polysomnography, and the high sensitivity in detecting patients with an AHI of > 20, may make the Autoset a valuable tool for the management of typical patients with sleep apnoea. However, very low values for nasal ventilation on the printout raises the suspicion of poor signal quality and misleading results.     

Post partum headache after epidural analgesia without dural puncture

In order to improve our knowledge of post partum headache, during a two-year period we studied a large population of pregnant patients of our institution using a four-stage process including two questionnaires (the first at 12-15 weeks' gestation and the second in the first week after delivery), a pre-anesthetic visit at 36 +/- 2 weeks' gestation and a computer printout obtained at delivery. Of 1058 patients for whom records were complete and who had epidural analgesia during labor not complicated by dural puncture, 128 (12.1%) complained of post partum headache. In patients who did not receive epidural analgesia, the incidence of post partum headache tended to be higher (15.2%). However, because of the low response rate (27.1%) and the low absolute number of patients with headache (27) in the non-epidural group, statistical comparison was not possible. Data from the medical history or from the current pregnancy as well as data obtained during delivery (maternal and fetal-neonatal) were not significantly different between those patients free of pain and those presenting with headache, except for a history of migraine and pregnancy-induced hypertension which were both associated with an increased risk of post partum headache. These risk factors should be considered in both clinical studies and obstetric malpractice claims.     

Pitfalls in bone mineral density measurements

Bone mineral density (BMD) measurements have been the single greatest advancement for osteoporosis. BMD measurements have helped define a prefracture diagnosis of osteoporosis, predict fracture risk in postmenopausal women and elderly men, and monitor the course of disease processes that negatively affect bone or therapeutic agents that can improve bone strength. Despite the large amount of clinical, epidemiologic, and basic science data that has advanced our understanding of BMD performance and interpretation, many pitfalls in BMD performance and interpretation pervade the practice of bone densitometry. However, all of these pitfalls can be overcome. Proper quality control and clinical interpretation of BMD computer printout reports are paramount for correct diagnosis, risk assessment, and serial BMD measurements. Though BMD application(s) are a clinical tool that can and should be used by many different primary care and specialty physicians, the performances and interpretations are not simple processes. Proper education and training in the use of BMD technologies provides the means of achieving the great intent that BMD measurements are capable of providing.     

The automated interview versus the personal interview. Do patient responses to preoperative health questions differ?

Laboratory testing of presurgical patients has been shown to be excessive, thereby increasing costs, reducing resources for other health care uses, and increasing risks to both patients and physicians. As one step toward reducing the number of unnecessary preoperative tests ordered, we used an automated method to aid preoperative assessment of 239 patients in Chicago and in Winnipeg. The "HealthQuiz," a small hand-held device containing a computer chip and video screen, uses a decision tree to ask a minimum of 60 health-related questions (the patient's response to certain questions determines the number of questions presented). The device then generates a summary printout of patient answers, the health areas needing further attention, and the laboratory tests most likely to uncover clinically important abnormalities in that patient. HealthQuiz responses are intended to aid the physician and not to replace the personal interview. As an aid, the automated interview highlights possible problem areas for in-depth pursuit by the physician. The need for nonselective batteries of tests is eliminated because recommendations for tests are based on specific elements of a patient's history. To be effective, responses to the HealthQuiz should be the same as responses to similar questions asked by a physician. We tested that premise in this study. Patient's answers to the HealthQuiz were compared with their responses to a randomly selected set of the same questions in a personal interview. Ninety-seven percent of the response pairs were identical, and most of the 3% that differed involved changes from "not sure" replies to the HealthQuiz. Laboratory tests suggested by responses to the two methods of questioning did not differ.(ABSTRACT TRUNCATED AT 250 WORDS)     

In vitro burn model illustrating heat conduction patterns using compressed thermal papers

To date, heat conduction from heat sources to tissue has been estimated by complex mathematical modeling. In the present study, we developed an intuitive in vitro skin burn model that illustrates heat conduction patterns inside the skin. This was composed of tightly compressed thermal papers with compression frames. Heat flow through the model left a trace by changing the color of thermal papers. These were digitized and three‐dimensionally reconstituted to reproduce the heat conduction patterns in the skin. For standardization, we validated K91HG‐CE thermal paper using a printout test and bivariate correlation analysis. We measured the papers' physical properties and calculated the estimated depth of heat conduction using Fourier's equation. Through contact burns of 5, 10, 15, 20, and 30 seconds on porcine skin and our burn model using a heated brass comb, and comparing the burn wound and heat conduction trace, we validated our model. The heat conduction pattern correlation analysis (intraclass correlation coefficient: 0.846, p < 0.001) and the heat conduction depth correlation analysis (intraclass correlation coefficient: 0.93, p < 0.001) showed statistically significant high correlations between the porcine burn wound and our model. Our model showed good correlation with porcine skin burn injury and replicated its heat conduction patterns.     

Virtual placement of frontal ventricular catheters using frameless neuronavigation: an "unbloody training" for young neurosurgeons.

OBJECTIVE: To evaluate virtually the reliability of freehand puncture of the anterior horn of the lateral ventricle and to provide realistic, but unbloody training for young neurosurgeons. METHODS: Virtual placement of ventricular catheters was performed repeatedly by neurosurgical doctors and thereafter controlled by neuronavigation. With the help of a frameless stereotactic navigation device they virtually had to hit the anterior horn of the lateral ventricle on the MRI of 29 brains with normal ventricular sizes and 60 pathological ventricles, respectively. The catheter placement was simulated using the pointer of the navigation system (EasyGuide Neuro). The monitor screen was blinded, so that on-line control was impossible. Virtual elongation of the pointer tip was performed on the workstation and the position of the virtual catheter was evaluated on a printout. RESULTS: Virtual freehand catheter placement was performed 145 times into the MRIs of the normal brains. In 66 cases (45%) the site of the catheter tip was judged as accurate as shown by the navigation system. No difference concerning the number of correctly placed catheters was observed when comparing more and less experienced doctors. The results in the 60 pathological MRIs of patients differed with respect to the size of the ventricles: in narrow ventricles an accurate placement succeeded in 7 of 22 cases (32%), moderately enlarged ventricles were accurately hit in 15 out of 32 cases (46%) and wide ventricles in 5 of 6 attempts (83%), respectively. CONCLUSION: This setup is a simple, practicable tool for neurosurgical education. The virtual freehand placement of ventricular drains controlled by neuronavigation provides an unbloody training of a routine neurosurgical procedure in a realistic setting without the risk of injuring a patient. Neuronavigation systems can serve therefore as a link between learning from observation and handling the real situation.     

Permanent Charge Effects on Ionic Flow: A Numerical Study of Flux Ratios and Their Bifurcation

Ionic flow carries electrical signals for cells to communicate with each other. The permanent charge of an ion channel is a crucial protein structure for flow properties while boundary conditions play a role of the driving force. Their effects on flow properties have been analyzed via a quasi-one-dimensional Poisson-Nernst-Planck model for small and relatively large permanent charges. The analytical studies have led to the introduction of flux ratios that reflect permanent charge effects and have a universal property. The studies also show that the flux ratios have different behaviors for small and large permanent charges. However, the existing analytical techniques can reveal neither behaviors of flux ratios nor transitions between small and large permanent charges. In this work we present a numerical investigation on flux ratios to bridge between small and large permanent charges. Numerical results verify the analytical predictions for the two extremal regions. More significantly, emergence of non-trivial behaviors is detected as the permanent charge varies from small to large. In particular, saddle-node bifurcations of flux ratios are revealed, showing rich phenomena of permanent charge effects by the power of combining analytical and numerical techniques. An adaptive moving mesh finite element method is used in the numerical studies.     

Selection of the most compatible graft recipient by computer program, used in regional tissue typing laboratory of Hellas (R.T.T.L)

Abstract The purpose of this study was to present the new computer program that we developed in the regional tissue typing laboratory (R. T. T. L.) and use for the selection of the most suitable recipient for cadaveric allografts in a more efficient way. This new program was written and compiled in TURBO PASCAL 6.0, sorts all possible recipients to the HLA type of a donor, checks for the existence of splits and utilises them, and when requested, gives out results to more specific inquiries, i.e. all compatible recipients from 2DR2B2A to 1 DROBOA matching. It can also forecast success percentages according to different factors, i.e. combination of donor's and recipient's ages, HLA matching etc. The material used for this study were the patients who are registered in the formal cadaveric tranplantation list of R. T. T. L. We have used this program since 2 January 1992 together with the old one. Since then we found that the new program is faster in sorting all the possible recipients of cadaveric renal allografts according to the criteria already mentioned. The total selection time, with all the criteria activated, averages a few seconds, whereas with the old program it took approximately 2 min just for the sorting of HLA matching, without any other criteria activated. In the printout of the final result of each inquiry are all the possible recipients in the sorted order together with relevant data (telephone number, address etc.). As a result, the laboratory personnel has been free from the tedious task of this sorting which was initially done by hand and the possibility of error has been eliminated. The program was developed exclusively by doctors and all the updates needed are done by the users. More important, however, is the fact that in many cases the time of cold ischaemia was reduced by more than 30 min with all the obvious advantages for the longevity of the graft's life.     

The effect of computerized tailored brief advice on at-risk drinking in subcritically injured trauma patients

BACKGROUND: One-third of injured patients treated in the emergency department (ED) have an alcohol use disorder (AUD). Few are screened and receive counseling because ED staff have little time for additional tasks. We hypothesized that computer technology can screen and provide an intervention that reduces at-risk drinking (British Medical Association criteria) in injured ED patients. METHODS: In all, 3,026 subcritically injured patients admitted to an ED were screened for an AUD using a laptop computer that administered the AUD Identification Test (AUDIT) and assessed motivation to reduce drinking. Patients with a positive AUDIT (n = 1,139) were randomized to an intervention (n = 563) or control (n = 576) condition. The computer generated a customized printout based on the patient's own alcohol use pattern, level of motivation, and personal factors, which was provided in the form of feedback and advice. RESULTS: Most patients (85%) used the computer with minimal assistance. At study entry, a similar proportion in each group met criteria for at-risk drinking (49.6% versus 46.8%, p = 0.355). At 6 months, 21.7% of intervention and 30.4% of control patients met criteria for at-risk drinking (p = 0.008). Intervention patients also had a 35.7% decrease in alcohol intake, compared with a 20.5% decrease in controls (p = 0.006). At 12 months, alcohol intake decreased by 22.8% in the intervention group versus 10.9% in controls (p = 0.023), but the proportion of at-risk drinkers did not significantly differ (37.3% versus 42.6%, p = 0.168). CONCLUSIONS: The computer-generated intervention was associated with a significant decrease in alcohol use and at-risk drinking. Research is needed to further evaluate and adapt information technology to provide preventive clinical services in the ED.     

Transmission line matrix modelling of thermal injuries to skin

A numerical model based on the transmission line matrix method is presented for the quantitative prediction of skin burn resulting from exposure of a specific region of human skin surface to a high temperature heat source. Transient temperatures were numerically estimated by Pennes' bioheat equation, and the damage function denoting the extent of burn was calculated using the Arrhenius assumptions for protein damage rate. A two-dimensional transmission line matrix model was used to predict the effects of exposure time and structure thicknesses on the transient temperature distribution and damage extent. Compared with other numerical sources the transmission line matrix results revealed good agreement, suggesting that this method may be an effective tool for the thermal diagnostic of burns.     

The relationships among DNA ploidy type determined by laser scanning cytometry, the overexpression of p53 protein and the numerical aberrations of chromosome 7 in bladder cancer

The cellular DNA content of certain malignancies is regarded as a prognostic parameter. The mutant p53 is thought to destabilize centrosome replication, which leads to aberrant mitosis and chromosome instability. We investigated the relationship among DNA ploidy pattern type, numerical aberrations of chromosome 7 and p53 overexpression in 20 transitional cell carcinomas of the urinary bladder. The DNA ploidy pattern type was determined by laser scanning cytometry, while p53 overexpression was investigated immunohistochemically. Using fluorescence in situ hybridization with chromosome-specific probes, the copy number of chromosome 7 was counted by touch preparations of interphase nuclei. The cytometric analysis revealed that the DNA patterns were highly correlated with both the numerical aberrations of chromosome 7 (p = 0.0002) and the overexpression of p53. The incidences of p53 overexpression in DNA aneuploid tumors and DNA diploid ones were 78% and 10%, respectively (p = 0.0017). Our results suggest that the overexpression of abnormal p53 protein induces DNA aneuploidy in bladder cancer.