Quality of anticoagulation control and costs of monitoring warfarin therapy among patients with atrial fibrillation in clinic settings: a multi-site managed-care study

BACKGROUND: Warfarin is recommended for prevention of stroke in patients with atrial fibrillation who are at moderate or high risk, but requires intensive management to achieve safe and optimal anticoagulation control. Anticoagulation clinics are often used to administer warfarin therapy more effectively. OBJECTIVE: To collect data from multiple sites and assess the quality and costs associated with anticoagulation clinic services. METHODS: A random sample of 600 adults with chronic nonvalvular atrial fibrillation (CNVAF) receiving warfarin was selected from anticoagulation clinics affiliated with 3 health plans. Patients were identified between 1996 and 1998 and followed for up to one year. We assessed the proportion of time that international normalized ratio (INR) values were within the recommended range (2.0-3.0) and the costs of anticoagulation clinic care. RESULTS: Patients had an average of 18 clinic contacts over a mean duration of follow-up of 10.5 months. On average, patients were within the recommended INR range 62% of this time, with 25% of days below range and 13% above range. The mean per-patient cost of warfarin monitoring over the follow-up period averaged $261 at site A, $305 at site B, and $205 at site C (in 2003 US$). Mean costs for patients treated for one full year were $288, $339, and $216, respectively. CONCLUSIONS: In 3 geographically diverse health plans, anticoagulation clinics provided a generally higher quality of control than previously reported in other observational studies. This study highlights the costs of obtaining this level of control.     

A model for studying epithelial attachment and morphology at the interface between skin and percutaneous devices

Percutaneous devices are indispensable in modern medicine, yet complications from their use result in significant morbidity, mortality, and cost. Bacterial biofilm at the device exit site accounts for most infections in short-term devices. We hypothesize that advanced biomaterials can be developed that facilitate attachment of skin cells to percutaneous devices, forming a seal to preclude bacterial invasion. To study the skin/biomaterial interface systematically, we first identified biomaterials with physical properties compatible with histological processing of skin. Second, we developed an organ culture system to study skin response to implants. Organ cultures implanted with porous poly(2-hydroxyethyl methacrylate) [poly(HEMA)] or polytetrafluoroethylene (PTFE) could easily be evaluated histologically with preservation of the skin/biomaterial interface. Epithelial cells migrated down the cut edges of the biomaterial in a pattern seen in marsupialization of percutaneous devices in vivo. This in vitro model maintains skin viability and allows histologic evaluation of the skin/biomaterial interface, making this a useful, inexpensive test-bed for studies of epidermal attachment to modified biomaterials.     

Flumazenil reverses sedation after midazolam-induced general anesthesia in ambulatory surgery patients

Flumazenil, a specific competitive benzodiazepine antagonist, was evaluated for reversal of residual sedation after midazolam-induced ambulatory general anesthesia. Endotracheal anesthesia was begun with midazolam (mean +/- SD dose 12.4 +/- 2.4 mg), followed by nitrous oxide in oxygen, fentanyl, and succinylcholine, for gynecologic surgery lasting 38.6 +/- 12.5 min. After surgery, 29 women were given repeated injections of small amounts of either flumazenil or placebo until awake and calm. The mean flumazenil dose was 0.83 +/- 0.04 mg. Assessment of recovery was based on psychodiagnostic tests (visual analog sedation scale, Trieger dot, digit symbol substitution), pulse oxygen saturation, and end-expired carbon dioxide tension. Patients given flumazenil scored significantly better than did those given placebo on the psychodiagnostic tests for 5-60 min, but the groups were no longer different 120 and 180 min after the conclusion of surgery. All scores did not return to preoperative values by 180 min. Pulse oxygen saturation and end-expired carbon dioxide tension showed improvement from postoperative levels at 15 min after flumazenil injection. A controllable degree of midazolam reversal was achieved with flumazenil, but the duration of reversal was limited. Caution is needed to avoid premature discharge of ambulatory patients after midazolam-induced general anesthesia during the time that flumazenil is effective.     

Components of coagulation and fibrinolysis during thrombosis prophylaxis with a low molecular weight heparin (Enoxaparin) versus Dextran 70 in hip arthroplasty.

In a prospective randomized study heptest, thrombin-antithrombin complexes (TAT), D-dimer, and t-PA:ag were analysed pre- and postoperatively in 206 consecutive patients undergoing hip arthroplasty during thromboprophylaxis with either a LMW heparin (Enoxaparin) or Dextran 70. Deep vein thrombosis (DVT) developed in 6 of 102 (6%) Enoxaparin and in 21 of 104 (20%) Dextran patients diagnosed by bilateral phelobography. In the Enoxaparin group heptest showed a significant increase from the pre- to the postoperative level opposed to a significant decrease in the Dextran group. Postoperative levels of TAT, D-dimer, and t-PA:ag were significantly increased in both groups, however, TAT was significantly higher in patients in the Dextran group than in the Enoxaparin patients. D-dimer was significantly higher in Dextran patients with DVT postoperatively compared with patients without DVT. No differences concerning TAT or t-PA:ag were observed between patients with and without DVT in any of the groups.     

Die Beziehung des Mitralöffnungstones zum Druck im linken Vorhof

Zusammenfassung Wie die Untersuchungen an 58 Kranken mit Mitralstenose zeigen, ist es möglich, ein annähernd exaktes Bild von der Druckhöhe im linken Vorhof mit Hilfe des Phonokardiogrammes zu gewinnen. Die Untersuchungen hatten zur Voraussetzung, daß eine einwandfreie Lungencapillardruckkurve als Abbild der linksseitigen Vorhofdruckkurve beim Herzkatheterismus registriert wurde und gleichzeitig im Phonokardiogramm ein Mitralöffnungston nachzuweisen war. Das zeitliche Auftreten des Mitralöffnungstones nach dem 2. Herzton stellt sich als eine Funktion des linken Vorhofdruckes bzw. des Druckgradienten durch die Mitralklappe dar. Dieses läßt sich auch bei absoluter Arrhythmie und den dabei von Schlag zu Schlag wechselnden Füllungsbedingungen nachweisen. Annäherungswerte für den Vorhofdruck lassen sich hier durch Festlegung eines mittleren Frequenzwertes ebenfalls mit dem Phonokardiogramm gewinnen. Bei der Auswertung ist weiter die Frequenzabhängigkeit der Werte zu berücksichtigen, sowie eine ebenfalls bestehende Abhängigkeit des Abstandes IIa–IIb vom jeweiligen systolischen Blutdruckwert. In Parallele zum Intervall des Mitralöffnungstones vom 2. Herzton läßt sich weiterhin eine — reziproke — Abhängigkeit der Umformungszeit vom Druckgradienten durch die Mitralklappe in zahlreichen Fällen nachweisen. Die Einbeziehung dieses Wertes in die erstgenannten Berechnungen ergibt jedoch keine größere Genauigkeit als die Berücksichtigung des Mitralöffnungstones allein.Auf die erforderliche Einschränkung des bisherigen Begriffes der stummen Mitralstenosen als Ausdruck einer Verschwielung des Mitralsegels wird aufmerksam gemacht. Die Untersuchungen lassen eine Einschränkung des Herzkatheterismus bei Kranken mit Mitralstenosen in der prä- und postoperativen Beurteilung zu.Die Untersuchungen wurden mit Unterstützung der Deutschen Forschungsgemeinschaft und unter Mitarbeit von Fräulein Dr.E. Heidenhain durchgeführt.     

Robot-Assisted Versus Standard Laparoscopic Colorectal Surgery

Background and Objectives:

Over the years, there has been a continual shift toward more minimally invasive surgical techniques, such as the use of laparoscopy in colorectal surgery. Recently, there has been increasing adoption of robotic technology. Our study aims to compare and contrast robot-assisted and laparoscopic approaches to colorectal operations.

Methods:

Forty patients undergoing laparoscopic or robotic colorectal surgery performed by 2 surgeons at an academic center, regardless of indication, were included in this retrospective review. Patients undergoing open approaches were excluded. Study outcomes included operative time, estimated blood loss, length of stay, complications, and conversion rate to an open procedure.

Results:

Twenty-five laparoscopic and fifteen robot-assisted colorectal surgeries were performed. The mean patient age was 61.1 ± 10.7 years in the laparoscopic group compared with 61.1 ± 8.5 years in the robotic group (P = .997). Patients had a similar body mass index and history of abdominal surgery. Mean blood loss was 163.3 ± 249.2 mL and 96.8 ± 157.7 mL, respectively (P = .385). Operative times were similar, with 190.8 ± 84.3 minutes in the laparoscopic group versus 258.4 ± 170.8 minutes in the robotic group (P = .183), as were lengths of hospital stay: 9.6 ± 7.3 and 6.5 ± 3.8 days, respectively (P = .091). In addition, there was no difference in the number of lymph nodes harvested between the laparoscopic group (14.0 ± 6.5) and robotic group (12.3 ± 4.2, P = .683).

Conclusions:

In our early experience, the robotic approach to colorectal surgery can be considered both safe and efficacious. Furthermore, it also preserves oncologically sufficient outcomes when performed for cancer operations.     

Fatal pulmonary embolism associated with surgery. An autopsy study

The records of all autopsies performed at two major Danish hospitals in 1986 were reviewed in order to analyze cases of fatal pulmonary embolism. There were 2,609 hospital deaths and 1,603 post mortem examinations. Pulmonary embolism was the primary cause of 74 deaths, 16 of which were postoperative. The median age of these ten men and six women was 72 years. In nine of the 16 cases the prognosis would have been favorable had embolism not occurred. Only three of the 16 had received thromboembolic prophylaxis. Four of the deaths from embolism occurred less than 24 hours after surgery, five within 7 days and seven between postoperative days 7 and 30. The estimated incidence of fatal pulmonary embolism following surgery was 1.2-1.3 per thousand.