PubMed Health⌕ Search

Biomedical subjects

D Prentice

Publications and source records attributed to D Prentice.

At least 19 recordsLinked to original sources
PubMed2005

Short communication: Efficacy of parenteral ceftiofur for treatment of systemically mild clinical mastitis in dairy cattle.

The objective of this study was to evaluate the effect of intramuscular (i.m.) ceftiofur (2.2 mg/kg) on important outcomes of systemically mild clinical mastitis episodes in lactating dairy cattle. Cows with clinical mastitis were randomly assigned to a treatment group: pirlimycin intramammary (i.m.m.) (n = 35), pirlimycin i.m.m. and ceftiofur i.m.m. (n = 36), cephapirin i.m.m. (n = 40), cephapirin i.m. and ceftiofur i.m. (n = 33). Sixty-nine, 22, and 9% of initial cultures were gram-negative, gram-positive, and mixed, respectively. Logistic regression analysis showed no significant associations between treatment groups and loss of quarter, recurrence, or culling. Mixed infections, positive milk culture at 7 d after leaving hospital pen, decreased rumen motility, and absence of udder firmness were associated with increased odds of mastitis recurrence. The results suggest that i.m. ceftiofur treatment has no beneficial effects on the outcome of systemically mild clinical mastitis.

Animals↗
PubMed2001

Relaxation of mouse isolated aorta to adenosine and its analogues does not involve adenosine A(1), A(2) or A(3) receptors.

Relaxations to adenosine and analogues were investigated in the mouse aorta in the presence of the adenosine A(1) receptor-selective antagonist 1,3-dipropyl-8-cyclopentylxanthine (DPCPX, 30 nM), which did not affect relaxations to adenosine or its analogue N(6)-R-phenylisopropyladenosine (R-PIA) but abolished contractile adenosine A(1) receptor-mediated responses to these agonists. Relaxations to adenosine, 5'-N-ethylcarboxamidoadenosine, R-PIA, 2-[p-(2-carbonylethyl)-phenylethylamino]-5'-N-ethylcarboxamidoadenosine (CGS 21680), and N(6)-(3-iodobenzyl)-adenosine-5'-N-methyluronamide (IB-MECA) were unaffected by the adenosine A(1)/A(2) receptor antagonist 8-sulphophenyltheophylline (100 microM). IB-MECA relaxations were unaffected by the adenosine A(3) receptor-selective antagonist 3-ethyl-5-benzyl-2-methyl-6-phenyl-4-phenylethynyl-1,4-(+/-)-dihydropyridine-3,5-dicarboxylate (MRS1191, 30 microM) and R-PIA relaxations were unaffected by N(G)-nitro-L-arginine methyl ester (100 microM) and endothelium removal. In conclusion, relaxant responses to adenosine and analogues do not involve adenosine A(1), A(2) or A(3) receptors and are endothelium- and nitric oxide-independent.

Adenosine↗
PubMed2001

Controversies in the use of the pulmonary artery catheter.

The pulmonary artery catheter (PAC) has been in use for more than 30 years. The amount and detail of hemodynamic information provided by the PAC cannot be matched by any other single technology. Whether or not this information makes a difference in the clinical outcomes of critically ill patients is uncertain, however. The Pulmonary Artery Catheter Consensus Conference scrutinized the available research data on the catheter and provided guidelines for clinicians on its use. This article summarizes the controversy and the guidelines available for use of the PAC. It notes the need for further research on patient outcomes.

Catheterization, Swan-Ganz↗
PubMed2001

Migraine and hypertension. Is there a relationship?

BACKGROUND Migraine and hypertension are common conditions that frequently coexist. The relastionship between the two is usually coincidental, but some evidence suggests that poor control of blood pressure may exacerbate the frequency and severity of migraine. OBJECTIVE To review the relationship between migraine, other headaches and blood pressure and to discuss guidelines for suitable therapy for both conditions when they occur together. DISCUSSION Establishing the blood pressure should be a routine task in the assessment of all headache patients. Severe hypertension in the setting of new acute headache may indicate a serious underlying cause and requires urgent investigation. In patients with migraine and established hypertension, good control of blood pressure may be beneficial in controlling their headache. Many of the drugs used to treat hypertension may cause headache and some agents used to treat migraine can exacerbate hypertension and so careful consideration of the therapeutic options is important.

Analgesics↗
PubMed2000

A school and community outbreak of tuberculosis in Auckland.

AIM: To describe a school and community outbreak of tuberculosis in South Auckland in 1997/8. METHODS: Cases were diagnosed according to national guidelines at Middlemore, Green Lane and Starship Hospitals. Public health follow-up was conducted by Auckland Healthcare. RESULTS: Twelve cases were diagnosed during the outbreak. Nine cases were from the same South Auckland secondary school; six reported no association outside school. Three cases were in younger children who had close household contact with two of the school cases. Nine cases (including eight from the school) had identical Mycobacterium tuberculosis isolates on restriction fragment length polymorphism testing. No microbiological culture was obtained from the three remaining cases. Contact investigation detected five of the cases. Chemoprophylaxis was prescribed for twenty-six school students, two adult staff, and nine household contacts. CONCLUSION: This is the first published account of a tuberculosis outbreak in a New Zealand school setting for decades. Recognition of the outbreak was delayed. DNA fingerprinting played a valuable role in the investigation. The source case may have been a school student. The social impact of the outbreak and preventability with routine adolescent BCG vaccination are discussed.

Adolescent↗
PubMed2000

Inadequate treatment of nosocomial infections is associated with certain empiric antibiotic choices.

OBJECTIVE: The purpose of this study was to determine the impact of scheduled changes of antibiotic classes, used for the empirical treatment of suspected or documented Gram-negative bacterial infections, on the occurrence of inadequate antimicrobial treatment of nosocomial infections. DESIGN: Prospective observational study. SETTING: Medical (19-bed) and surgical (18-bed) intensive care units in an urban teaching hospital. PATIENTS: A total of 3,668 patients requiring intensive care unit admission were prospectively evaluated during three consecutive time periods. INTERVENTIONS: During each time period, one antibiotic class was selected for the empirical treatment of Gram-negative bacterial infections as follows: time period 1 (baseline period) (1,323 patients), ceftazidime; time period 2 (1,243 patients), ciprofloxacin; and time period 3 (1,102 patients), cefepime. MEASUREMENTS AND MAIN RESULTS: The overall administration of inadequate antimicrobial treatment for nosocomial infections decreased during the course of the study (6.1%, 4.7%, and 4.5%; p = .15). This was primarily because of a statistically significant decrease in the administration of inadequate antibiotic treatment for Gram-negative bacterial infections (4.4%, 2.1%, and 1.6%; p < .001). There were no statistically significant differences in the overall hospital mortality rate among the three time periods (15.6%, 16.4%, and 16.2%; p = .828) despite a significant increase in severity of illness as measured with Acute Physiology and Chronic Health Evaluation (APACHE) II scores (15.3 +/- 7.6, 15.7 +/- 8.0, and 20.7 +/- 8.6; p < .001). The hospital mortality rate decreased significantly during time period 3 (20.6%) compared with time period 1 (28.4%; p < .001) and time period 2 (29.5%; p < .001) for patients with an APACHE II score > or = 15. CONCLUSIONS: These data suggest that scheduled changes of antibiotic classes for the empirical treatment of Gram-negative bacterial infections can reduce the occurrence of inadequate antibiotic treatment for nosocomial infections. Reducing inadequate antibiotic administration may improve the outcomes of critically ill patients with APACHE II scores > or = 15.

APACHE↗
PubMed1999

Effect of a nursing-implemented sedation protocol on the duration of mechanical ventilation.

OBJECTIVE: To compare a practice of protocol-directed sedation during mechanical ventilation implemented by nurses with traditional non-protocol-directed sedation administration. DESIGN: Randomized, controlled clinical trial. SETTING: Medical intensive care unit (19 beds) in an urban teaching hospital. PATIENTS: Patients requiring mechanical ventilation (n = 321). INTERVENTIONS: Patients were randomly assigned to receive either protocol-directed sedation (n = 162) or non-protocol-directed sedation (n = 159). MEASUREMENTS AND MAIN RESULTS: The median duration of mechanical ventilation was 55.9 hrs (95% confidence interval, 41.0-90.0 hrs) for patients managed with protocol-directed sedation and 117.0 hrs (95% confidence interval, 96.0-155.6 hrs) for patients receiving non-protocol-directed sedation. Kaplan-Meier analysis demonstrated that patients in the protocol-directed sedation group had statistically shorter durations of mechanical ventilation than patients in the non-protocol-directed sedation group (chi-square = 7.00, p = .008, log rank test; chi-square = 8.54, p = .004, Wilcoxon's test; chi-square = 9.18, p = .003, -2 log test). Lengths of stay in the intensive care unit (5.7+/-5.9 days vs. 7.5+/-6.5 days; p = .013) and hospital (14.0+/-17.3 days vs. 19.9+/-24.2 days; p < .001) were also significantly shorter among patients in the protocol-directed sedation group. Among the 132 patients (41.1%) receiving continuous intravenous sedation, those in the protocol-directed sedation group (n = 66) had a significantly shorter duration of continuous intravenous sedation than those in the non-protocol-directed sedation group (n = 66) (3.5+/-4.0 days vs. 5.6+/-6.4 days; p = .003). Patients in the protocol-directed sedation group also had a significantly lower tracheostomy rate compared with patients in the non-protocol-directed sedation group (10 of 162 patients [6.2%] vs. 21 of 159 patients [13.2%], p = .038). CONCLUSIONS: The use of protocol-directed sedation can reduce the duration of mechanical ventilation, the intensive care unit and hospital lengths of stay, and the need for tracheostomy among critically ill patients with acute respiratory failure.

Algorithms↗
PubMed1998

A randomized clinical trial comparing an extended-use hygroscopic condenser humidifier with heated-water humidification in mechanically ventilated patients.

STUDY OBJECTIVE: To determine the safety and cost-effectiveness of mechanical ventilation with an extended-use hygroscopic condenser humidifier (Duration; Nellcor Puritan-Bennett; Eden Prairie, Minn) compared with mechanical ventilation with heated-water humidification. DESIGN: Prospective randomized clinical trial. SETTING: Medical and surgical ICUs of Barnes-Jewish Hospital, St. Louis, a university-affiliated teaching hospital. PATIENTS: Three hundred ten consecutive qualified patients undergoing mechanical ventilation. INTERVENTIONS: Patients requiring mechanical ventilation were randomly assigned to receive humidification with either an extended-use hygroscopic condenser humidifier (for up to the first 7 days of mechanical ventilation) or heated-water humidification. MEASUREMENTS: Occurrence of ventilator-associated pneumonia, endotracheal tube occlusion, duration of mechanical ventilation, lengths of intensive care and hospitalization, acquired multiorgan dysfunction, and hospital mortality. RESULTS: One hundred sixty-three patients were randomly assigned to receive humidification with an extended-use hygroscopic condenser humidifier, and 147 patients were randomly assigned to receive heated-water humidification. The two groups were similar at the time of randomization with regard to demographic characteristics, ICU admission diagnoses, and severity of illness. Risk factors for the development of ventilator-associated pneumonia were also similar during the study period for both treatment groups. Ventilator-associated pneumonia was seen in 15 (9.2%) patients receiving humidification with an extended-use hygroscopic condenser humidifier and in 15 (10.2%) patients receiving heated-water humidification (relative risk, 0.90; 95% confidence interval=0.46 to 1.78; p=0.766). No statistically significant differences for hospital mortality, duration of mechanical ventilation, lengths of stay in the hospital ICU, or acquired organ system derangements were found between the two treatment groups. No episode of endotracheal tube occlusion occurred during the study period in either treatment group. The total cost of providing humidification was $2,605 for patients receiving a hygroscopic condenser humidifier compared with $5,625 for patients receiving heated-water humidification. CONCLUSION: Our findings suggest that the initial application of an extended-use hygroscopic condenser humidifier is a safe and more cost-effective method of providing humidification to patients requiring mechanical ventilation compared with heated-water humidification.

Adolescent↗
PubMed1998

The use of continuous i.v. sedation is associated with prolongation of mechanical ventilation.

STUDY OBJECTIVE: To determine whether the use of continuous i.v. sedation is associated with prolongation of the duration of mechanical ventilation. DESIGN: Prospective observational cohort study. SETTING: The medical ICU of Barnes-Jewish Hospital, a university-affiliated urban teaching hospital. PATIENTS: Two hundred forty-two consecutive ICU patients requiring mechanical ventilation. INTERVENTIONS: Patient surveillance and data collection. MEASUREMENTS AND RESULTS: The primary outcome measure was the duration of mechanical ventilation. Secondary outcome measures included ICU and hospital lengths of stay, hospital mortality, and acquired organ system derangements. A total of 93 (38.4%) mechanically ventilated patients received continuous i.v. sedation while 149 (61.6%) patients received either bolus administration of i.v. sedation (n=64) or no i.v. sedation (n=85) following intubation. The duration of mechanical ventilation was significantly longer for patients receiving continuous i.v. sedation compared with patients not receiving continuous i.v. sedation (185+/-190 h vs 55.6+/-75.6 h; p<0.001). Similarly, the lengths of intensive care (13.5+/-33.7 days vs 4.8+/-4.1 days; p<0.001) and hospitalization (21.0+/-25.1 days vs 12.8+/-14.1 days; p<0.001) were statistically longer among patients receiving continuous i.v. sedation. Multiple linear regression analysis, adjusting for age, gender, severity of illness, mortality, indication for mechanical ventilation, use of chemical paralysis, presence of a tracheostomy, and the number of acquired organ system derangements, found the adjusted duration of mechanical ventilation to be significantly longer for patients receiving continuous i.v. sedation compared with patients who did not receive continuous i.v. sedation (148 h [95% confidence interval: 121, 175 h] vs 78.7 h [95% confidence interval: 68.9, 88.6 h]; p<0.001). CONCLUSION: We conclude from these preliminary observational data that the use of continuous i.v. sedation may be associated with the prolongation of mechanical ventilation. This study suggests that strategies targeted at reducing the use of continuous i.v. sedation could shorten the duration of mechanical ventilation for some patients. Prospective randomized clinical trials, using well-designed sedation guidelines and protocols, are required to determine whether patient-specific outcomes (eg, duration of mechanical ventilation, patient comfort) can be improved compared with conventional sedation practices.

Adolescent↗
PubMed1997

Sequential increases in the intrahepatic expression of epidermal growth factor, basic fibroblast growth factor, and transforming growth factor beta in a bile duct ligated rat model of cirrhosis.

Chronic hepatic regeneration constitutes an important part of the cirrhotic process. The factors regulating chronic hepatic regeneration, however, remain unclear. We therefore analyzed the intrahepatic messenger RNA (mRNA) expression of growth factors (epidermal growth factor [EGF], basic fibroblast growth factor [bFGF], hepatocyte growth factor [HGF], transforming growth factor [TGF]-alpha, and TGF-beta) at progressive time points (postoperative days 2, 7, 14, and 21) in a rat bile duct-ligated (BDL) model of cirrhosis versus sham controls. Intrahepatic growth factor mRNA expression was quantitatively assessed by polymerase chain reaction (PCR) using a dot-blot hybridization technique. Cirrhosis was associated with statistically significant (P < .05) progressive increases in the intrahepatic mRNA expression of bFGF (80-fold), EGF (25-fold), and TGF-beta (fourfold) in BDL animals versus controls. Furthermore, immunohistochemistry of hepatic sections showed a progressive up-regulation of bFGF protein in areas of bile duct proliferation. These areas also showed a dramatic increase in the number of hepatic stellate cells (HSC). In contrast, the intrahepatic expression of hepatocyte growth factor (HGF) mRNA was only significantly increased at postoperative days 7 and 14 in BDL animals before returning to control levels as cirrhosis developed. There were no significant differences found at any timepoint in the expression of TGF-alpha in BDL animals versus controls. In conclusion, the development of cirrhosis in this BDL rat model was associated with a progressive increase in the intrahepatic expression of EGF, bFGF, and TGF-beta. Early increased expression of HGF was not maintained in established cirrhosis. The findings suggest that these growth factors may play important roles in the pathogenesis of chronic hepatic regeneration in cirrhosis.

Animals↗
PubMed1997

A randomized, controlled trial of protocol-directed versus physician-directed weaning from mechanical ventilation.

OBJECTIVE: To compare a practice of protocol-directed weaning from mechanical ventilation implemented by nurses and respiratory therapists with traditional physician-directed weaning. DESIGN: Randomized, controlled trial. SETTING: Medical and surgical intensive care units in two university-affiliated teaching hospitals. PATIENTS: Patients requiring mechanical ventilation (n = 357). INTERVENTIONS: Patients were randomly assigned to receive either protocol-directed (n = 179) or physician-directed (n = 178) weaning from mechanical ventilation. MEASUREMENTS AND MAIN RESULTS: The primary outcome measure was the duration of mechanical ventilation from tracheal intubation until discontinuation of mechanical ventilation. Other outcome measures included need for reintubation, length of hospital stay, hospital mortality rate, and hospital costs. The median duration of mechanical ventilation was 35 hrs for the protocol-directed group (first quartile 15 hrs; third quartile 114 hrs) compared with 44 hrs for the physician-directed group (first quartile 21 hrs; third quartile 209 hrs). Kaplan-Meier analysis demonstrated that patients randomized to protocol-directed weaning had significantly shorter durations of mechanical ventilation compared with patients randomized to physician-directed weaning (chi 2 = 3.62, p = .057, log-rank test; chi 2 = 5.12, p = .024, Wilcoxon test). Cox proportional-hazards regression analysis, adjusting for other covariates, showed that the rate of successful weaning was significantly greater for patients receiving protocol-directed weaning compared with patients receiving physician-directed weaning (risk ratio 1.31; 95% confidence interval 1.15 to 1.50; p = .039). The hospital mortality rates for the two treatment groups were similar (protocol-directed 22.3% vs. physician-directed 23.6%; p = .779). Hospital cost savings for patients in the protocol-directed group were $42,960 compared with hospital costs for patients in the physician-directed group. CONCLUSION: Protocol-guided weaning of mechanical ventilation, as performed by nurses and respiratory therapists, is safe and led to extubation more rapidly than physician-directed weaning.

Adult↗
PubMed1997

Mechanical ventilation with or without daily changes of in-line suction catheters.

The purpose of this study was to determine the safety and cost-effectiveness of not routinely changing in-line suction catheters for patients requiring mechanical ventilation. Patients were randomly assigned to receive either no routine in-line suction catheter changes (n = 258) or in-line suction catheter changes every 24 h (n = 263). The main outcome measure was the incidence of ventilator-associated pneumonia. Other outcomes evaluated included hospital mortality, acquired organ system derangements, duration of mechanical ventilation, lengths of intensive care and hospital stay, and the cost for in-line suction catheters. Ventilator-associated pneumonia was seen in 38 patients (14.7%) receiving no routine in-line suction catheter changes and in 39 patients (14.8%) receiving in-line suction catheter changes every 24 h (relative risk, 0.99; 95% CI, 0.66 to 1.50). No statistically significant differences for hospital mortality, lengths of stay, the number of acquired organ system derangements, death in patients with ventilator-associated pneumonia, or mortality directly attributed to ventilator-associated pneumonia were found between the two treatment groups. Patients receiving in-line suction catheter changes every 24 h had 1,224 catheter changes costing a total of $11,016; patients receiving no routine in-line suction catheter changes had a total of 93 catheter changes costing $837. Our findings suggest that the elimination of routine in-line suction catheter changes is safe and can reduce the costs associated with providing mechanical ventilation.

Adult↗
PubMed1997

Patient transport from intensive care increases the risk of developing ventilator-associated pneumonia.

STUDY OBJECTIVE: To determine whether patient transport out of the ICU is associated with an increased risk of developing ventilator-associated pneumonia. DESIGN: Prospective cohort study. SETTING: ICUs of Barnes-Jewish Hospital, a university-affiliated teaching hospital. PATIENTS: Five hundred twenty-one ICU patients requiring mechanical ventilation for > 12 h. INTERVENTION: Prospective patient surveillance and data collection. MEASUREMENTS AND RESULTS: The primary outcome measure was the development of ventilator-associated pneumonia. A total of 273 (52.4%) mechanically ventilated patients required at least one transport out of the ICU while 248 (47.6%) patients did not undergo transport. Sixty-six (24.2%) of the transported patients developed ventilator-associated pneumonia compared with 11 (4.4%) patients in the group not undergoing transport (relative risk=5.5; 95% confidence interval [CI]=2.9 to 10.1; p<0.001). Multiple logistic regression analysis demonstrated that a preceding episode of transport out of the ICU was independently associated with the development of ventilator-associated pneumonia (adjusted odds ratio=3.8; 95% CI=2.6 to 5.5; p<0.001). Other variables independently associated with the development of ventilator-associated pneumonia included reintubation, presence of a tracheostomy, administration of aerosols, and male gender. CONCLUSIONS: We conclude that patient transport out of the ICU is associated with an increased risk for the development of ventilator-associated pneumonia.

APACHE↗