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Biomedical subjects

D G Bjoraker

Publications and source records attributed to D G Bjoraker.

At least 19 recordsLinked to original sources
PubMed1998

Portable devices used to detect endotracheal intubation during emergency situations: a review.

OBJECTIVES: To review the operational characteristics of commercial devices used to detect endotracheal intubation; and to identify an ideal device for detecting endotracheal intubation in emergency situations, especially in the prehospital setting during cardiac arrest. DATA SOURCES: Relevant articles from the medical literature are referenced. STUDY SELECTION: The authors identified the need for understanding the basic operation principles of portable devices used to detect endotracheal intubation and to correctly use them in unpredictable clinical situations. DATA EXTRACTION: Data from published literature. DATA SYNTHESIS: Recently, a number of new portable devices have been marketed for detecting endotracheal intubation, each having advantages and disadvantages, especially when used during emergency situations. The devices are classified based on their principle of operation. Some rely on CO2 detection (STATCAP, Easy Cap, and Pedi-Cap), others utilize the transmission of light (Trachlight, SURCH-LITE), one operates based on reflection of sound energy (SCOTI), and some depend on aspiration of air (TubeChek and TubeChek-B). A brief description of each device and its operational characteristics are reviewed. A comparative analysis among the devices is made based on size, portability, cost, ease of operation, need for calibration or regular maintenance, reliability for patients with and without cardiac arrest, and the possibility of use for adult and pediatric patients. False-negative and false-positive results for each device are also discussed. False-negative results mean that although the endotracheal tube is in the trachea, the device indicates it is not. False-positive results mean that although the endotracheal tube is in the esophagus, the device indicates it is in the trachea. CONCLUSIONS: Although no clinical comparative study of commercial devices to detect endotracheal intubation exists, the syringe device (TubeChek) has most of the characteristics necessary for a device to be considered ideal in emergency situations in the prehospital setting. It is simple, inexpensive, easy to handle and operate, disposable, does not require maintenance, gives reliable results for patients with and without cardiac arrest, and can be used for almost all age groups. The device may yield false-negative results, most commonly in the presence of copious secretions and in cases of accidental endobronchial intubation. Regardless of the device used, clinical judgment and direct visualization of the endotracheal tube in the trachea are required to unequivocally confirm proper endotracheal tube placement.

Capnography↗
PubMed1995

Maximum blood savings by acute normovolemic hemodilution.

Acute normovolemic hemodilution (ANH) entails collecting blood from a patient immediately prior to surgery with concurrent fluid infusion to maintain intravascular volume constant. Blood collected during ANH is later reinfused to replace the red cell losses that occur during surgery. This technique is advocated as a means to reduce or eliminate homologous blood transfusion during surgery. Published guidelines for performing ANH vary, and the literature does not describe how to perform ANH to achieve the maximum benefit for a given patient. To evaluate how to save red blood cells as much as possible via ANH, and to determine the maximum benefit that can be expected, we developed a mathematic model of the process. Using the model, the net red cell mass savings possible when using ANH can be calculated given the patient's weight, initial hematocrit and minimum safe hematocrit. Results are reported to demonstrate the impact of the initial hematocrit and minimum safe hematocrit on the red cell savings possible with ANH. The data indicate that ANH does indeed save red blood cells that would otherwise be lost during surgery. However, the red cell savings possible when using ANH are not as much as typically published and, a degree of hemodilution more than that which is typically recommended is necessary to achieve even modest red cell savings.

Blood Transfusion, Autologous↗
PubMed1987

Evaluation of an emergency cricothyrotomy instrument.

An emergency cricothyrotomy device was placed in 11 anesthetized dogs in order to assess airway damage and problems in placement, ventilation, and design. Posterior airway perforation without esophageal damage occurred in three animals. Submucosal hematomas or cricoid cartilage injury occurred in seven animals. As placement by an untrained operator was surprisingly difficult, prior operator training with this device is recommended. When properly installed, an excellent emergency airway was achieved. Some minor design shortcomings are noted and suggestions for improvement are made.

Airway Obstruction↗
PubMed1984

Experience with microcomputer management of a personal medical literature collection.

Microcomputers may be conveniently and effectively used to manage personal medical literature collections. A bibliographic data base consisting of the author, title, and source for each reference is entered and stored on magnetic tapes or disks. Document categorization and keyword assignment prior to entry is optional, thus allowing clerical personnel to maintain both the literature collection and the bibliographic data base. Subject searches using an array of search terms formulated by the medical user permit retrieval of relevant bibliographic citations. Current alphabetical and keyword-in-context listings of the documents in the the collection may also be produced. The programming approach uses string processing and is within the capability of programmers with limited experience.

Computers↗
PubMed1984

Intravenous nitroglycerin administration during infrarenal aortic clamping.

Twenty-five patients requiring infrarenal abdominal aortic clamping were studied during halothane, nitrous oxide anaesthesia. Aortic clamping caused reductions in cardiac index (CI), stroke volume index (SVI) and left ventricular stroke work index (LVSWI). Systemic vascular resistance (SVR) increased. In seven patients CI was less than 1.81 X min-1 X m-2. Intravenous administration of nitroglycerin, 1 microgram X kg-1 X min-1, for 20 minutes, accompanied by volume loading to maintain pulmonary capillary wedge pressure, resulted in a significant improvement in haemodynamic parameters. CI increased 24 per cent as a result of a 14 per cent increase in SVI and an eight per cent increase in heart rate. LVSWI increased 13 per cent and SVR decreased 21 per cent. The plasma nitroglycerin concentration at the time of these measurements was 2.9 +/- 1.0 ng X ml-1. Aortic unclamping resulted in a mean maximum decrease of 14 +/- 2 torr mean arterial pressure. Epinephrine, norepinephrine and plasma renin activity gradually increased during the period of the anaesthetic.

Aged↗
PubMed1983

Hemodynamic and platelet response to the bolus intravenous administration of porcine heparin.

There is considerable evidence that under some conditions intravenous heparin infusion may cause or at least enhance platelet aggregation in vivo. Reports of heparin-induced vasodilatation and decreases in arterial blood pressure have not been accompanied by simultaneous observations of the platelet response. In this study both the hemodynamic and platelet response to the bolus administration of porcine intestinal mucosa sodium heparin were monitored in 24 cardiac and 12 vascular surgery patients. Mean arterial blood pressure decreased 7.1 +/- 0.8 mmHg as a result of a 247 +/- 34 dyne X sec/cm5 decrease in systemic vascular resistance. Platelet count, platelet volume distribution, and beta-thromboglobulin levels did not change with heparin infusion. These responses did not differ when comparing the 155 unit/kg group and the 400 unit/kg group or the 400 unit/kg groups treated with different commercial preparations. The single patient who did have a decrease in platelet count and a severe rise in beta-thromboglobulin with heparin died intraoperatively of a massive myocardial infarction. Large increases in platelet factor 4 with heparin administration were not associated with platelet release but were dependent on whether or not the patient was treated with preoperative subcutaneous or intravenous heparin. There was no evidence that heparin-induced vasodilatation was mediated by platelet aggregation and release.

Animals↗
PubMed1981

Incidence of choledochoduodenal sphincter spasm during fentanyl-supplemented anesthesia.

One hundred patients were studied prospectively to assess the incidence of spasm of the choledochoduodenal sphincter during biliary tract surgery performed under a fentanyl-supplemented anesthetic technique. The incidence of failure of passage of contrast medium into the duodenum was 3%. In each of the three patients with cholangiographic evidence of sphincter spasm, contrast medium flowed freely into the duodenum after the intravenous administration of 2 mg of glucagon. It is concluded that spasm of the choledochoduodenal sphincter is an uncommon occurrence during fentanyl-supplemented anesthesia and that this method of anesthesia is suitable for biliary tract surgery.

Ampulla of Vater↗
PubMed1979

Failure of clinical concentrations of halothane to block adenosine diphosphate-induced platelet aggregation in vitro.

A dose-related inhibition by halothane of adenosine diphosphate-induced platelet aggregation was measured for human platelets in plasma anticoagulated with sodium citrate 6.8 mmol litre-1 or 13.6 mmol litre-1, or heparin 2 u. ml-1 and for platelets separated from plasma by albumin density gradient centrifugation and requiring no anticoagulant. By maintaining exposure and assay temperature at 37 degrees C, maintaining physiological pH, avoiding age-related deterioration and using an atraumatic equilibration method, no inhibition was found at clinical concentrations of halothane and 50% inhibition required greater than halothane 10%. Sodium citrate, a calcium chelating anticoagulant, was found to enhance halothane inhibition.

Adenosine Diphosphate↗
PubMedDate not supplied

Carbon dioxide laser burn of laryngotracheobronchial mucosa.

A CO2 laser fire in the laryngotracheobronchial tree occurred because of an increase in fraction of inspired oxygen to greater than 40%. An endotracheal tube was ignited and caused a severe burn of respiratory mucosa that required treatment in a burn intensive care unit. The patient had surprisingly few immediate respiratory complications and was discharged from the hospital 25 days after the burn.

Burns, Chemical↗