Search PubMed⌕ Search

Biomedical subjects

David J Powner

Publications and source records attributed to David J Powner.

24 records · Page 2Linked to original sources
PubMed2003

Advanced assessment of hemodynamic parameters during donor care.

Detailed evaluation of cardiovascular function by hemodynamic "profiling" during donor care may be necessary to select appropriate treatment for hypotension. Preload, systemic vascular resistance, heart rate, and contractility are all determinants of cardiac output and blood pressure. This review discusses the measurement, physiological limitations, and pharmacological manipulation of those variables during care of selected donors.

Hemodynamics↗
PubMed2002

Tetany following resuscitation after abruptio placentae.

BACKGROUND: Serum ionized calcium and magnesium are normally decreased during later stages of pregnancy. A further rapid decline may be caused by the rapid infusion of blood bank products in which citrate is used as an anticoagulant/preservative. Tetany, as reported here, may be precipitated by such infusions. CASE: A gravid woman presented in hemorrhagic shock due to abruptio placentae. Rapid infusion of packed red blood cells and fresh frozen plasma precipitated signs of tetany, muscle rigidity, posturing, high airway pressure during mechanical ventilation, etc. Ionized calcium and magnesium blood levels were very low (0.58 mmol/L and 1.0 mg/dL, respectively), but responded to rapid electrolyte administration. CONCLUSION: Binding of calcium and magnesium by citrate may lead to hypo-ionized calcemic and hypomagnesemic tetany after rapid replacement of blood products in the pregnant patient. This consequence is worsened when extreme alkalemia due to respiratory or metabolic causes is also present.

Abruptio Placentae↗
PubMed2002

Airway considerations for professional singers--a survey of expert opinion.

The objective of this study was to survey physician experts in voice disorders/treatment to establish consensus guidelines for translaryngeal intubation (TLI) and tracheotomy when treating professional singers or other voice professionals. A written survey was sent to all physician members of the Voice Foundation seeking opinions/recommendations about route of TLI, duration of TLI before tracheotomy, size of endotracheal and tracheotomy tubes, and special interventions during patient care as these might differ between professional singers and nonsingers. Fifty-five percent of the physicians responded, of whom 73% classified their experience in voice care as "extensive." A strong consensus (76%) favored a smaller endotracheal tube for singers (6-7 mm I.D. for males and 6.0 mm I.D. for females) via the oral (46%) versus nasal (36%) route. Intubation/extubation by the most expert/experienced personnel was emphasized so as to minimize direct trauma to the larynx. While intubated, strong recommendations were made to suppress gastric acid production and to minimize motion of the endotracheal tube, including patient sedation. Preferences for an early tracheotomy (6 days) versus their usual time (10 days) were approximately equal (44% vs. 50%, respectively) and most respondents (69%) recommended the same size tracheotomy tube (8.0 mm I.D. for males and 6.0 mm I.D. for females) for singers and nonsingers. Post extubation/decannulation care emphasized voice rest, retraining, continued gastric acid suppression, and the possibility of direct laryngoscopy to assess post-TLI or tracheotomy injuries.

Choice Behavior↗
PubMed2002

A review of "chest tubes" during donor care and after transplantation.

Thoracostomy tubes, also called chest tubes, are commonly present after transplantation or during donor care. The function of the thoracostomy tube is to provide a conduit for transporting fluid, gas, or blood from the pleural cavity to an attached drainage unit. Malfunction of the tube or parts of the unit assembly may lead to serious consequences and jeopardize transplant recipient recovery or donor organs. This review discusses the components of the thoracostomy tube and drainage unit assembly, normal operation, routine evaluation, and common problems that the organ procurement or transplantation coordinator may need to anticipate or treat.

Chest Tubes↗
PubMedDate not supplied

CVP and PAoP measurements are discordant during fluid therapy after traumatic brain injury.

The objective of the study was to compare measurements of central venous pressure (CVP) and pulmonary artery occlusion pressures (PAoP) as estimates of intravascular volume during the first 96 hours of fluid therapy after traumatic brain injury (TBI). One thousand five hundred ten simultaneous CVP and PAoP measurements from 31 patients entered into the National Acute Brain Injury Study: Hypothermia (NABISH:H) protocol were retrospectively compared. The effect of fluid administration and body temperature upon the paired measurements was statistically assessed. Agreement between CVP and PAoP values was poor. The CVP and PAoP were equal in only 11% of paired values. The CVP was always higher than PAoP in 1 patient, whereas PAoP always exceeded the CVP in 5 others. In 74% of the pairs, the PAoP was higher than the CVP, whereas in 15%, CVP was greater than PAoP. For any CVP measurement, the PAoP was either 3 mm Hg above or below the CVP in 67% of the pairs and at least 5 mm Hg above or below the CVP in 21% of the pairs. In 21 (68%) patients, PAoP was > or = 5 mm Hg above CVP in more than 4 readings, a clinically important difference. Discordance was not attributed to the fluid administered or to the temperature protocol. Neurological outcome appears affected by the volume of fluid administration. However, during initial therapy, estimates of intravascular volume provided by the CVP and PAoP are discordant. Although documented in other clinical conditions, the disparity noted here after TBI has not been previously reported. Assessment of intravascular volume to avoid hypovolemia should utilize other measurement techniques.

Adult↗