PubMed Health⌕ Search

Biomedical subjects

K N Hoffman

Publications and source records attributed to K N Hoffman.

6 recordsLinked to original sources
PubMed1996

Laboratory assays and duplex scanning outcomes after symptomatic deep vein thrombosis: preliminary results.

PURPOSE: The purpose of this article was to assess a number of hematologic and fibrinolytic assays at the time of diagnosis of deep vein thrombosis (DVT) and at several intervals over a period of 6 months afterward and to correlate these results with the results of serial duplex scanning. METHODS: Thirty-five patients (average age 61, range 18 to 82) with acute symptomatic DVT confirmed by duplex scanning were included. On diagnosis, blood was drawn, and plasma levels of tissue-type plasminogen activator (t-PA), plasminogen activator inhibitor (PAI), D-dimer (DD), and tissue factor pathway inhibitor (TFPI) were determined. Duplex scanning and all laboratory assays were repeated 1 week, 1 month, 3 months, and 6 months thereafter. RESULTS: The rate of DVT complete resolution 6 months after diagnosis was 57%. Whereas plasma levels of PAI were similar throughout the 6-month follow-up period, t-PA increased significantly 1 week after diagnosis and decreased thereafter. Both DD and TFPI levels decreased significantly after diagnosis compared with presentation values. Comparing these assay levels between patients with complete resolution versus partial or no resolution, PAI levels were significantly higher during the first week in patients with poor outcome. Plasma levels of t-PA were higher in cases with good outcome, and DD levels were higher in patients with poor outcome. TFPI levels were similar in both outcome groups. CONCLUSIONS: Patients with complete DVT resolution on duplex scanning at 6 months had significantly lower levels of PAI on presentation and after 1 week than did those with incomplete lysis. Although differences were not significant, t-PA levels were higher and DD lower in patients with good outcome. Our results suggest that certain plasma fibrinolytic assays might correlate with the outcome of DVT, as assessed by duplex ultrasonography.

Adolescent↗
PubMed1995

Postoperative hypercoagulability and deep-vein thrombosis after laparoscopic cholecystectomy.

Patients who undergo laparoscopic cholecystectomy (LC) are operated on under general anesthesia, in a reverse Trendelenburg position, with 12-15-mmHg pneumoperitoneum. All of these factors can induce venous stasis of the legs, which may lead to postoperative deep-vein thrombosis (DVT). The objectives of this study were to assess the degree of hypercoagulability and to determine the rate of postoperative DVT in a group of 100 patients in whom LC was completed. Whole-blood thrombelastography (TEG) and plasma-activated partial thromboplastin time (PTT) determination were carried out preoperatively and on the 1st postoperative day. All patients received pre-, intra-, and postoperative graduated compression stockings and sequential pneumatic compression devices until fully ambulatory. Twenty-six percent of the patients with a risk score > 4, or a post-operative TEG index > +5.0, received subcutaneous heparin (5,000 units b.i.d.), beginning in the postoperative period and continuing for 4 weeks as an outpatient. A complete venous duplex scan of both legs was performed on the 7th postoperative day, at the time of their office visit. Our results revealed significant postoperative hypercoagulability for the TEG index (P < 0.005) and for PTT (P < 0.05). One patient had an asymptomatic DVT (1%), and no side effects from the mechanical or pharmacological prophylaxis occurred in this series. These data suggest that the low incidence of thrombosis in the face of theoretical and laboratory evidence of postoperative hypercoagulability may reflect an effective prophylactic regime.(ABSTRACT TRUNCATED AT 250 WORDS)

Bandages↗
PubMed1995

Modifications of plasma levels of tissue factor pathway inhibitor and endothelin-1 induced by a reverse Trendelenburg position: influence of elastic compression--preliminary results.

PURPOSE: The purpose of this study was to assess the effects of the passive 45-degree reverse Trendelenburg position and graduated compression stockings (GCS) on plasma tissue factor pathway inhibitor (TFPI) and endothelin-1 levels in a group of volunteers. METHODS: Ten healthy subjects lay on an examining table for 30 minutes while baseline measurements were made. The table was then tilted to a 45-degree upright position for 60 minutes, and measurements were repeated. On a different day, subjects were tilted again, but on this occasion they wore thigh-length GCS. Blood was drawn before and 60 minutes after tilting during both sessions, and plasma TFPI and endothelin-1 were obtained. Cross-sectional areas of the calf medial gastrocnemius vein, before and after tilting, were measured by a duplex scanner. RESULTS: Upright tilting induced a significant dilation of the medial gastrocnemius veins that was partially corrected by the use of elastic stockings. Similarly, endothelin-1 levels significantly increased after tilting. The use of GCS did not modify these differences. On the other hand, although TFPI levels were not affected by tilting without stockings, they were significantly elevated after tilting when GCS were used. CONCLUSIONS: Upright passive tilting induces significant dilation of the deep calf veins and is associated with a significant increase in plasma levels of endothelin-1, whereas TFPI levels remain unchanged. The use of elastic stockings reduces the degree of calf distention but does not prevent an increase in endothelin-1. TFPI levels are significantly increased after tilting when GCS are used. This might represent a previously unknown mechanism of action of elastic stockings with interesting potential for deep vein thrombosis prophylaxis. More studies are warranted in a larger series to confirm these results.

Adult↗
PubMed1995

Venous duplex imaging follow-up of acute symptomatic deep vein thrombosis of the leg.

PURPOSE: The purpose of this study was to evaluate the rate of resolution of deep vein thrombosis (DVT) in the leg, by means of duplex imaging, in patients with symptoms during a 6-month period after initial diagnosis. METHODS: Seventy-three limbs in 69 patients with acute DVT diagnosed by duplex imaging received conventional heparin and warfarin treatment and underwent subsequent duplex studies 1, 4, 12, and 24 weeks after the initial diagnosis. The objectives of the study were to document (1) the rate or complete resolution of DVT, (2) the proportion of unstable, floating thrombi, and (3) the development of chronic damage as a result of vessel wall scarring. RESULTS: The rate of normalization of DVT 6 months after diagnosis was 78% in the common femoral vein, 70% in the superficial femoral vein, 75% in the popliteal vein, and 70% in the calf veins examined at the scheduled intervals. Twenty-six percent of thrombi were considered unstable on the baseline examination. The average number of days necessary for these thrombi to become stable was 10.7 days. Damage to the vessel wall or valves was documented in 44% of the patients. CONCLUSIONS: Rates of resolution of DVT were similar for the different veins of the leg studied. There was a high proportion of unstable thrombi, which present a high potential risk of embolization. Serial duplex scanning after DVT renders important information with regard to thrombus resolution, propagation, and attachment to the vein wall.

Acute Disease↗
PubMed1993

Symptom relief after endoscopic sinus surgery: an outcomes-based study.

Previous studies of patients outcomes after sinus surgery have generally described only a summary measure of overall change in symptoms or health status. This paper describes an outcomes-based longitudinal study of sinus symptom prevalence among thirty-one patients treated with endoscopic surgery for chronic sinusitis. Patients completed structured data collection forms to quantify the prevalence of commonly experienced sinus-related symptoms during an eight-week period both before surgery and six months after undergoing sinus surgery. Significant decreases in nasal symptom prevalence (post-surgery versus pre-surgery) were noted for headaches, nasal drainage, nasal congestion, sinus infection, and breathing difficulties. In addition, the proportion of subjects who rated their current health as "better" compared to one year previously increased from 27% pre-surgery to 58% six months after sinus surgery. These findings aid in quantifying the magnitude of improvement experienced by sinus surgery patients and provide further evidence that endoscopic sinus surgery represents an effective treatment for chronic sinusitis.

Adult↗