Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Alan T. Davis is active.

Publication


Featured researches published by Alan T. Davis.


Journal of Parenteral and Enteral Nutrition | 2008

The Incidence of PICC Line–Associated Thrombosis With and Without the Use of Prophylactic Anticoagulants

James D. Paauw; Heather L. Borders; Nichole K. Ingalls; Sarah Boomstra; Susan Lambke; Brian Fedeson; Austin Goldsmith; Alan T. Davis

BACKGROUND Indications for peripherally inserted central catheters (PICC) for long-term venous access have grown during the last several years. There are various complications associated with PICC lines, a common one being venous thrombosis. This studys purpose was to determine the incidence of venous thrombosis associated with PICCs with and without prophylactic anticoagulants. METHODS In this observational, prospective, cohort study, patients with PICC lines were evaluated using Doppler ultrasound for the presence of PICC-associated venous thrombosis at 5-7 days and again at 12-14 days after line placement. When present, clinical signs and symptoms of thrombosis were documented. Fifty-six patients were evaluated for the type of anticoagulation used, if any, and other clinical parameters such as smoking, ambulation, and previous surgery. The incidence of thrombus was then calculated for the entire population as well as for specific patient subgroups. RESULTS Patient age was 55.7 +/- 2.6 (mean +/- SEM) years, and BMI was 28.2 +/- 1.2 (n = 56). There were 38 (67.9%) nonambulatory subjects, 15 (26.8%) smokers, 4 (7.1%) coagulopathic subjects, 2 (3.6%) patients receiving estrogen-containing medications, 25 (44.6%) who had undergone surgery within the past 6 months, and 5 (8.9%) cancer patients. There were 21/56 patients (37.5%) with thrombus. Patients who received anticoagulation had a 22.9% (8/35) incidence of thrombosis, which was significantly less (P < .05) than for those who received no anticoagulant (13/21, 61.9%). CONCLUSION The use of anticoagulants for prophylaxis in patients with a PICC line was associated with a decreased rate of associated venous thrombosis.


Journal of Parenteral and Enteral Nutrition | 2004

A randomized trial of endoscopic and fluoroscopic placement of postpyloric feeding tubes in critically ill patients.

James A. Foote; Paul R. Kemmeter; Pablo A. Prichard; Randal S. Baker; James D. Paauw; Jeffery C. Gawel; Alan T. Davis

BACKGROUND Early postpyloric feeding is considered the accepted method of nutrition support in critically ill patients. Endoscopic and fluoroscopic techniques are associated with the highest percentage of successful placement. The purpose of this study was to compare endoscopic vs fluoroscopic placement of postpyloric feeding tubes in critically ill patients. METHODS This is a randomized prospective clinical trial. Forty-three patients were randomized to receive feeding tubes by endoscopic or fluoroscopic technique. All procedures were performed at the bedside in the critical care unit. A soft small-bore nonweighted feeding tube was used in all cases. Successful placement was confirmed by either an abdominal x-ray for endoscopic technique or a fluoroscopic radiograph for fluoroscopic technique. RESULTS Postpyloric feeding tubes were successfully placed in 41 of 43 patients (95%). The success rate using endoscopic technique was 96% (25 of 26), whereas the rate using fluoroscopy was 94% (16 of 17). The average time of successful placement was 15.2 +/- 2.9 (mean +/- SEM) minutes for endoscopic placement and 16.2 +/- 3.2 minutes for fluoroscopic placement, which was not statistically significant (p > .05). CONCLUSIONS Endoscopic and fluoroscopic placement of postpyloric feeding tubes can safely and accurately be performed at the bedside in critically ill patients. Our results showed no significant difference in the success rate or time of placement between endoscopic vs fluoroscopic placement of postpyloric feeding tubes.


Journal of Parenteral and Enteral Nutrition | 2005

Hyperemesis gravidarum and fetal outcome.

James D. Paauw; Sandra Bierling; Curtis R. Cook; Alan T. Davis

BACKGROUND Hyperemesis gravidarum (HG) is reported in 0.5-2% of all pregnancies. The purpose of this research was to evaluate the relationship of maternal HG, neonatal birth weight, and birth outcomes. METHODS This is a prospective cohort study of 45 patients diagnosed, by Fairweathers criteria, with HG compared with 306 non-HG control pregnant patients with singleton pregnancies. Sociodemographic and clinical data were obtained from the pregnant patients. Neonatal data were also collected, including indicators of neonatal wellness. RESULTS Significantly higher incidences of being nonwhite (33% vs 16%; p < .05) and of attaining post-high school education (60% vs 38%) were noted in the HG group, relative to controls. Mothers in the control group experienced greater gestational weight gain, 14.9 +/- 0.3 kg (mean +/- SEM) relative to mothers in the HG group (10.6 +/- 1.3 kg). Infants from HG pregnancies manifested significantly lower birth weight (3.23 +/- 0.09 kg vs 3.52 +/- 0.03 kg), younger gestational age (38.4 +/- 0.3 weeks vs 39.7 +/- 0.1 weeks), and a greater length of hospital stay (2.9 +/- 0.5 days vs 1.8 +/- 0.1 day), relative to infants from the control group. After undergoing multivariate analysis, HG was a significant predictor of decreased gestational age and increased hospital length of stay. CONCLUSIONS Infants born of women who had HG are more likely to experience decreased gestational age and increased length of hospital stay. Efficacy of early and aggressive treatment of HG, including nutrition support, in minimizing these outcomes needs to be studied.


Pediatric Critical Care Medicine | 2014

Therapeutic role of anakinra, an interleukin-1 receptor antagonist, in the management of secondary hemophagocytic lymphohistiocytosis/sepsis/multiple organ dysfunction/macrophage activating syndrome in critically ill children*.

Surender Rajasekaran; Katherine Kruse; Karen Kovey; Alan T. Davis; Nabil Hassan; Akunne Ndika; Sandra Zuiderveen; James D. Birmingham

Objectives: Secondary hemophagocytic lymphohistiocytosis, macrophage activating syndrome, and sepsis share the same inflammatory phenotype leading often to multiple organ dysfunction syndrome needing intensive care. The goal of this article is to describe our experience with anakinra (Kineret), a recombinant interleukin-1 receptor antagonist, in decreasing the systemic inflammation. Design: Retrospective case series. Setting: The PICU at the Helen DeVos Children’s Hospital (Grand Rapids, MI). Patients: The records of eight critically ill children presumed to have secondary hemophagocytic lymphohistiocytosis at our institution between January 1, 2011, and July 31, 2012, were reviewed. Interventions: All of the patients were treated with anakinra (Kineret) and in some cases systemic corticosteroids as first-line therapy for secondary hemophagocytic lymphohistiocytosis. Measurements and Main Results: Patients had a median age of 14 years and a median Pediatric Risk of Mortality score of 11.5. Four were previously healthy and four had underlying diseases that could have made them susceptible to secondary hemophagocytic lymphohistiocytosis. Indications for PICU transfer were respiratory distress 50% (4 of 8), cardiovascular instability 37.5% (3 of 8), and chest pain (1 of 8). Five of the patients (62.5%) were mechanically ventilated and 62.5% (5 of 8) received vasoactive infusions. Inflammatory markers were assessed linearly at the start of therapy and 7 days later. Baseline C-reactive protein was 206 ± 50 mg/L (mean ± SEM) at the start of anakinra and decreased by 67.1% to 68 ± 36 mg/L (p = 0.03). Ferritin decreased by 63.8% to 3,210 ± 1,178 ng/mL (p = 0.30), and fibrinogen decreased by 42% to 158 ± 41 mg/dL (p = 0.03). Absolute neutrophil count (p = 0.38) and absolute lymphocyte count (p = 0.69) did not change significantly. No infections were attributed to anakinra therapy. One patient died long after treatment with anakinra while receiving pre-hematopoietic stem cell transplant chemotherapy. Conclusions: Anakinra could represent a promising therapeutic approach in these life-threatening disorders that are likely underdiagnosed and often difficult to treat.


American Journal of Surgery | 2008

Mammographic distance as a predictor of nipple-areola complex involvement in breast cancer.

Margaret J. Loewen; Jill A. Jennings; Stanley R. Sherman; Jason Slaikeu; Pierson A. Ebrom; Alan T. Davis; Timothy L. Fitzgerald

BACKGROUND Although involvement of the nipple-areola complex (NAC) occurs in a minority of patients with breast cancer, standard skin-sparing mastectomy requires its removal. To assist in patient selection for NAC preservation we evaluated NAC involvement and correlated this with preoperatively available clinical data. METHODS Patients with invasive breast cancer or ductal carcinoma in situ undergoing mastectomy from 1998 to 2005 were reviewed retrospectively. The NAC had been evaluated with multiple thin sections. Pathologic data including NAC involvement were analyzed. The mammographic tumor distance from the nipple was measured in 2 standard views. RESULTS There were 302 patients enrolled, of which 10% were noted to have NAC involvement. This correlated negatively with tumor distance from the nipple (P < .05). A logistic regression equation was derived from the data, with NAC involvement as the dependent variable and distance from the nipple as the independent variable. The equation predicted involvement of the NAC when the distance was less than 4.96 cm with a sensitivity of 82% and a negative predictive value of 97%. CONCLUSIONS A majority of patients are candidates for NAC preservation. The mammographic distance between the tumor and the nipple is independently predictive of NAC involvement and is useful as an equation variable.


Journal of Trauma-injury Infection and Critical Care | 2010

Antiplatelet and anticoagulation therapies do not increase mortality in the absence of traumatic brain injury.

Mickey M. Ott; Evert Eriksson; Wayne E. Vanderkolk; David Christianson; Alan T. Davis; Donald J. Scholten

BACKGROUND : As the population continues to age, the number of patients undergoing traumatic injury while on antiplatelet or anticoagulation therapies is increasing. Mortality has been shown to increase in traumatic brain injury patients on warfarin therapy. Whether this increased mortality is seen in trauma patients without traumatic brain injury remains controversial. We investigated whether patients on antiplatelet and/or anticoagulation therapy were at increased risk of death from blunt traumatic injury in the absence of head injury. METHODS : A retrospective review of our Level I trauma center database was performed from 2002 to 2007. Inclusion criteria included all patients older than 60 years admitted to the trauma service. Only patients with a computed tomography scan negative for intracranial injury were analyzed. RESULTS : Two hundred twelve patients were found, of which 67 were found to be taking aspirin, warfarin, clopidogrel, or a combination of the three. Injury Severity Score (21 vs. 21), length of stay (11 days vs. 9 days), intensive care unit days (5 days vs. 4 days), and deaths (13% vs. 10%) were similar between those patients on antiplatelet/anticoagulation therapy and those who were not. CONCLUSION : In the absence of traumatic brain injury, the use of preinjury antiplatelet and/or anticoagulation therapy does not significantly increase the risk of mortality in the trauma patient. As the number of active seniors rises, this patient population will continue to present to the trauma service. To the best of our knowledge, this study is one of the largest addressing this question, and the only study examining the addition of antiplatelet therapy.


Catheterization and Cardiovascular Interventions | 2015

Detection by near-infrared spectroscopy of large lipid cores at culprit sites in patients with non-st-segment elevation myocardial infarction and unstable angina

Ryan D. Madder; Mustafa Husaini; Alan T. Davis; Stacie Van Oosterhout; Jan Harnek; Matthias Götberg; David Erlinge

This study was performed to assess the lipid burden of culprit lesions in non‐ST‐segment elevation myocardial infarction (non‐STEMI) and unstable angina (UA).


European Journal of Echocardiography | 2016

Large lipid-rich coronary plaques detected by near-infrared spectroscopy at non-stented sites in the target artery identify patients likely to experience future major adverse cardiovascular events

Ryan D. Madder; Mustafa Husaini; Alan T. Davis; Stacie VanOosterhout; Mohsin Khan; David Wohns; Richard McNamara; Kevin Wolschleger; John Gribar; J. Stewart Collins; Mark Jacoby; Jeffrey M. Decker; Michael J. Hendricks; Stephen T. Sum; Sean P. Madden; James H. Ware; James E. Muller

AIMS A recent study demonstrated that intracoronary near-infrared spectroscopy (NIRS) findings in non-target vessels are associated with major adverse cardiovascular and cerebrovascular events (MACCE). It is unknown whether NIRS findings at non-stented sites in target vessels are similarly associated with future MACCE. This study evaluated the association between large lipid-rich plaques (LRP) detected by NIRS at non-stented sites in a target artery and subsequent MACCE. METHODS AND RESULTS This study evaluated 121 consecutive registry patients undergoing NIRS imaging in a target artery. After excluding stented segments, target arteries were evaluated for a large LRP, defined as a maximum lipid core burden index in 4 mm (maxLCBI4 mm) ≥400. Excluding events in stented segments, Cox regression analysis was performed to evaluate for an association between a maxLCBI4 mm ≥400 and future MACCE, defined as all-cause mortality, non-fatal acute coronary syndrome, and cerebrovascular events. NIRS detected a maxLCBI4 mm ≥400 in a non-stented segment of the target artery in 17.4% of patients. The only baseline clinical variable marginally associated with MACCE was ejection fraction (HR 0.96, 95% CI 0.93-1.00, P = 0.054). A maxLCBI4 mm ≥400 in a non-stented segment at baseline was significantly associated with MACCE during follow-up (HR 10.2, 95% CI 3.4-30.6, P < 0.001). CONCLUSION Detection of large LRP by NIRS at non-stented sites in a target artery was associated with an increased risk of future MACCE. These findings support ongoing prospective studies to further evaluate the ability of NIRS to identify vulnerable patients.


European Journal of Cardio-Thoracic Surgery | 2011

Recombinant factor VIIa (NovoSeven RT) use in high risk cardiac surgery

Alistair J. Chapman; Andrew L. Blount; Alan T. Davis; Robert L. Hooker

OBJECTIVE The use of recombinant factor VIIa (rFVIIa) (NovoSeven RT(®)) to establish hemostasis during massive perioperative bleeding in cardiac surgery has been explored in several retrospective studies. While early results are promising, a paucity of data leaves many questions about its safety profile. We sought to further define its use and associated outcomes in a large cohort study at a single institution. METHODS A retrospective cohort study design was used, in which 236 patients received rFVIIa for bleeding after cardiac surgery. These patients were matched with a cohort of 213 subjects, who had similar operations during the same period of time. Primary end points included thrombo-embolic events, mortality, incidence of re-operation, use of blood products, and patient disposition at 30 days. Statistical significance was assessed at p < 0.05. RESULTS There was no statistically significant difference in the incidence of stroke (3.4%, 1.9%; p = 0.32), renal failure (8.5%, 7.0%; p = 0.57), or 30-day mortality (7.7%, 4.3%; p = 0.14) between the rFVIIa and the control groups, respectively. The rFVIIa group did experience a higher rate of re-operation for bleeding (11.0%, 1.9%; p = 0.0001) and had a two-fold increase in the use of each of the following: cryoprecipitate, fresh-frozen plasma, platelets, and packed red blood cells, relative to the control group (p < 0.00001). CONCLUSIONS rFVIIa is an effective hemostatic agent for intractable bleeding in high-risk cardiac surgery with an acceptable safety profile. rFVIIa does not appear to be associated with increased postoperative complications, including thrombo-embolic events and death.


Journal of Parenteral and Enteral Nutrition | 2006

Carnitine Treatment Improved Quality-of-Life Measure in a Sample of Midwestern Hemodialysis Patients

Alison Steiber; Alan T. Davis; Leslie Spry; Jennifer Strong; Mary Lou Buss; Michelle M. Ratkiewicz; Lorraine Weatherspoon

BACKGROUND Previously, we demonstrated that selected groups of hemodialysis patients might be more likely to have abnormalities of carnitine metabolism. The purpose of the present study was to examine the effects of carnitine therapy in these selected groups of hemodialysis patients on quality-of-life measures and erythropoietin dose. METHODS This was a double-blind, randomized, controlled trial, in which 50 hemodialysis patients were treated with either 2 g i.v. carnitine or placebo. The treatment period was for 24 weeks. RESULTS Thirty-four patients (15 in the treatment group) completed the study. The mean age was 69 +/- 15 years, 35% were women, and 44% had diabetes. Mean initial plasma total, free, short-chain acyl and long-chain acyl carnitine concentrations (micromol/L; mean +/- SEM) were 35.9 +/- 1.8, 18.2 +/- 1.1, 11.6 +/- 0.6, and 6.0 +/- 0.3, whereas the plasma acyl-to-free-carnitine ratio was 1.02 +/- 0.05. With respect to the Medical Outcomes Short Form-36 (SF-36), improvements from baseline were noted in the treatment group (n = 13) for role-physical (33.9 +/- 1.9 to 43.2 +/- 3.0, p < .05) and the SF-36 physical component summary score (36.1 +/- 2.7 to 39.7 +/- 2.3, p = .09) relative to changes in the control group (n = 14). The erythropoietin dose over the 24-week period was reduced from baseline in the treatment group relative to the placebo group (-1.62 +/- 0.91 vs 1.33 +/- 0.79 units erythropoietin/dry weight/hemoglobin concentration, respectively, p < .05). CONCLUSIONS After 24 weeks of i.v. carnitine therapy, SF-36 scores were improved and erythropoietin doses were reduced in hemodialysis patients, relative to the control group.

Collaboration


Dive into the Alan T. Davis's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

James D. Paauw

Michigan State University

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge