Transcutaneous oxygen recovery and toe pulse reappearance time in the assessment of peripheral vascular disease.

The accuracy of measurements of transcutaneous oxygen tension (Ptco2) in the diagnosis of peripheral vascular disease (PVD) may be significantly increased by stressing limb circulation with the use of temporary ischemia. The purpose of this study was to compare the transcutaneous oxygen recovery half-time (TORT) and the toe pulse reappearance time (PRT/2) in a series of patients with symptomatic PVD before and after vascular reconstruction. The TORT was defined as the time required to recover half of the decrease in the limb/chest Ptco2 ratio caused by temporary limb ischemia, and is conceptually comparable to the toe PRT/2, the time required to recover half of the control toe pulse amplitude.

Common bile duct anastomosis using fibrin glue.

Transection of the common bile duct (CBD) secondary to iatrogenic or civilian trauma is a devastating injury associated with a high incidence of complications, especially biliary fistula and stricture formation. We evaluated the efficacy of Fibrin Sealant--a biologic adhesive containing highly concentrated human fibrinogen--in primary end-to-end anastomosis of the transected CBD in ten adult mongrel dogs. Postoperative T-tube stents in the CBD anastomosis and abdominal drainage were not used.

Tracheal repair with fibrin glue.

This animal study evaluated Fibrin Sealant, a multicomponent biologic adhesive, in tracheal operations. We conclude that the use of Fibrin Sealant in tracheal reconstruction results in a stable, leakless trachea, has good systemic and local compatibility, promotes tracheal wound healing, and reduces significantly the number of sutures required for end-to-end anastomosis.

Continuous polarographic monitoring of intra-arterial oxygen in the perioperative period.

Intra-arterial PO2 (PiO2) was polarographically monitored in ten critically ill patients during induction of anesthesia, the intraoperative period, extubation, and the immediate postoperative period; 147 PiO2 values were then paired with simultaneous measurements of PaO2. Mean PiO2 closely followed mean PaO2 over a wide range of values (r = .97), and the continuous, online real-time PiO2 readings provided a useful early warning system for hypoxemia during crisis periods.

Controversies in the pathophysiology and fluid management of postoperative adult respiratory distress syndrome.

Physiologic changes that lead to the development of ARDS begin with the precipitating shock syndrome. Hypovolemia, pulmonary vasoconstriction, reduced myocardial performance, and diminished O2 transport typically precede the development of clinical ARDS after hemorrhage, trauma, postoperative conditions, and sepsis. Since shock lung is a complication of shock, it is not surprising that the antecedent clinical and physiologic events that characterize the shock state may be determinants of both the genesis and the outcome of ARDS.

Therapy of critically ill postoperative patients based on outcome prediction and prospective clinical trials.

An objective physiologic approach to therapy of high-risk postoperative patients was developed using survival as the criterion to determine the relative importance of variables and optimal goals for these variables. A protocol, based on a branch chain decision tree, also was developed from outcome data. When tested prospectively against the standard of care, this protocol markedly reduced mortality and morbidity.

Common physiologic patterns in general surgical patients: hemodynamic and oxygen transport changes during and after operation in patients with and without associated medical problems.

An examination of perioperative cardiorespiratory parameters in surviving and nonsurviving patients has identified several physiologic responses to the stress of surgical trauma, namely enhancement of circulatory performance and oxygen transport. When specific subsets of surgical illness are examined, it was found that these responses often began from different plateaus of baseline function. Because these responses are greater in survivors than nonsurvivors and this relationship is fairly consistent among a variety of surgical illnesses, it would seem that duplicating or augmenting these responses would be a rational goal for therapeutic intervention that would lead to improved patient outcome.

Cardiorespiratory patterns in severe delirium tremens.

To define the hemodynamic and oxygen metabolism patterns associated with severe delirium tremens, we examined cardiorespiratory variables in five patients over the 24 hours before (control), at the time of (delirium tremens), and during the 24 hours after resolution of (postresolution) delirium tremens. In comparing the delirium tremens period with the control period, significant increases were found in mean +/- SD cardiac index (4.9 +/- 1.

Pathophysiology of adult respiratory distress syndrome after sepsis and surgical operations.

To describe the natural history of adult respiratory distress syndrome (ARDS) from the circulatory viewpoint, we measured hemodynamic and oxygen transport variables in a series of 126 postoperative and 65 septic ARDS patients. All patients had hypoxemia unresponsive to conservative measures and required mechanical ventilation. Data from this series were compared with data from normal healthy volunteers and from postoperative patients who did not develop ARDS.

Characterization of the prodynorphin and proenkephalin neuropeptide systems in rat hippocampus.

Opioid peptides derived from prodynorphin were localized immunocytochemically to dentate granule cells and mossy fibers of the rat hippocampus with antisera against dynorphin A(1-17) and dynorphin B. Extracts of microdissected hippocampal regions were resolved by reverse phase and molecular exclusion chromatography to identify the molecular forms of the dynorphin A immunoreactivity and to quantify regional contents. Results demonstrated that the relative concentration of dynorphin A within each dissected region of hippocampus agreed well with the distribution of dynorphin A detected by immunocytochemical methods.

Probability of survival as a prognostic and severity of illness score in critically ill surgical patients.

A new quantitative method for measuring the prognosis and severity of illness in terms of probability of survival was developed from 224 studies in an index population of 220 critically ill surgical patients. Patients were selected preoperatively to eliminate pre-existing cardiac disease, cirrhosis, nutritional debility, shock or sepsis, in order to evaluate the physiologic relationships of surgical trauma to outcome free of confounding associated medical disorders. The empirically derived numeric severity index was calculated from the probability of survival for each of 28 hemodynamic and oxygen transport variables at each time period after surgery.

Hemodynamic and oxygen transport patterns in surviving and nonsurviving postoperative patients.

Invasive hemodynamic monitoring was performed on 220 critically ill surgical patients judged by clinical evaluation to have a high likelihood of surgical complications or death. Patients with markedly abnormal preoperative hemodynamic values were excluded from analysis. Data were separated into preoperative, intraoperative and postoperative time intervals and the mean value of each variable for each patient at each time period was computed.

Senescent change in tissue weight and immunoreactive beta-endorphin, enkephalin, and vasopressin in eight regions of C57BL/6J mouse brain and pituitary.

Tissue weights and immunoreactive (IR) content and concentration of beta-endorphin, enkephalin, and vasopressin were assayed for senescent change in anterior pituitary, neurointermediate pituitary, hypothalamus, hippocampus, striatum, dorsolateral cortex, and pons-medulla, as well as residual brain samples remaining after the other dissections. Groups of naive male C57BL/6J mice, 8-12 months old and 28-32 months old, served as subjects. Old mice exhibited significant decline in anterior pituitary and hippocampus weight.

The eye as a peripheral sensor.

The eye is no longer an organ onto itself, but is now being used as a sensor for the rest of the body. The development, clinical uses, and future applications of conjunctival capillary monitoring are presented.

Effect of hemorrhagic shock on conjunctival and transcutaneous oxygen tensions in relation to hemodynamic and oxygen transport changes.

To evaluate possible physiologic mechanisms in hemorrhagic shock, sequential hemodynamics, O2 transport, conjunctival O2 (PcjO2), transcutaneous blood gases (PtcO2, PtcCO2), and core and conjunctival temperature (Tcore, Tcj) were measured during a control period, after hemorrhage, after reinfusion of the shed blood, and subsequently during terminal normovolemic shock in eight anesthetized dogs. The PtcO2 sensor requires surface heating to 44 degrees or 45 degrees C, whereas the PcjO2 sensor measures surface temperature but does not heat the tissue, thus avoiding heat-induced artifacts. Shortly after onset of hemorrhage, hemodynamic variables, bulk O2 transport, and tissue O2 tensions decreased abruptly.

Oxygen transport and utilization in hyperoxia and hypoxia: relation of conjunctival and transcutaneous oxygen tensions to hemodynamic and oxygen transport variables.

A device to measure surface oxygen tension of the palpebral conjunctiva (PcjO2) was developed and tested in 12 mongrel dogs subjected to normoxia, hyperoxia, and hypoxia. Intravascular pressure, hemodynamic, and bulk oxygen transport variables were measured simultaneously with PcjO2 and transcutaneous O2 (PtcO2) and CO2 (PtcCO2). PcjO2 closely paralleled PaO2 as the fractional inspired O2 concentration was changed from 0.

Splenic salvage using biologic glue.

Fibrin sealant (FS) is a biologic adhesive containing highly concentrated human fibrinogen that is effective in the face-to-face sealing of tissues, and in establishing hemostasis. We evaluated FS in 32 experimentally produced splenic injuries in six adult mongrel dogs. Complete hemostasis was achieved in all animals prior to closure.

The use of surface oximetry to assess bowel viability.

Tissue depends on perfusion, but tissue oxygenation measurements have been impractical. To develop a method for the clinical evaluation of bowel viability, we studied PO2 on the bowel surface (PSO2). The PSO2 was assessed on the stomach and intestine of 11 dogs.

Developmental changes in rat liver alcohol dehydrogenase.

Hepatic alcohol dehydrogenase activity and mass content change coordinately during development in male rats. Enzyme activity and mass content increase continuously after birth to 100 and 80% of maximal values within 6 weeks (2.6 +/- 0.

Assessment of peripheral vascular disease by postocclusive transcutaneous oxygen recovery time.

A method for assessing peripheral vascular disease (PVD) was developed from the pattern of transcutaneous oxygen (PtcO2) changes after temporary limb ischemia induced by pneumatic blood pressure cuff occlusion. The transcutaneous oxygen recovery half-time (TORT) was defined as the time required to recover half of the decrease in the limb/chest PtcO2 ratio produced by temporary limb ischemia. TORT was examined in subjects with and without significant PVD.

Method for intraoperative assessment of organ perfusion and viability using a miniature oxygen sensor.

A specially designed miniaturized Clark polarographic electrode was used to measure organ surface oxygen tension during surgical operations in 10 patients as a means of determining tissue perfusion and viability. When applied to organ surfaces, the sensor noninvasively provides real-time assessment of tissue PO2. Values obtained are dependent on both arterial PO2 and local blood flow and therefore may be used to quantitatively assess local oxygen delivery (perfusion).