Biomedical subjects

P J Dennesen

Publications and source records attributed to P J Dennesen.

6 recordsLinked to original sources

PubMed2001

The development of ventilator-associated pneumonia does not change aspects of mechanical ventilation.

OBJECTIVE: To evaluate whether the development of ventilator-associated pneumonia (VAP) is associated with changes in ventilation parameters. DESIGN: Matched case-control study. SETTING: Mixed intensive care unit of a university hospital. PATIENTS: From a large database we selected 33 patients with VAP, diagnosed with quantitative cultures of bronchoscopically obtained specimens. In addition, 33 other mechanically ventilated patients who did not develop VAP were selected (controls). Patients with VAP and controls were matched on seven variables representing severity of illness: duration of ventilation until matching, diagnosis on admission, renal function, liver function, preceding infection, preceding surgery and immunosuppressive therapy. Each patient with VAP was matched to a single control. Variables regarding type and mode of ventilation and interpretation of chest radiographs were not included in the matching procedure. MEASUREMENTS AND RESULTS: Characteristics of mechanical ventilation (mode of ventilation, tidal volume, expired minute ventilation, peak airway pressures, mean airway pressures, level of positive end-expiratory pressure, arterial oxygen tension(PaO2)/fractional inspired oxygen (FIO2) ratio), were compared on the day of diagnosis of VAP (or matching for controls) and 2 and 4 days before. Although there was a significant difference in PaO2/FIO2 ratios between cases and controls on the day of diagnosis of VAP, the change in PaO2/FIO2 ratios during the days of study were not statistically different between patients developing VAP and controls. No significant differences were found for any of the other variables of ventilation at any of the three time points studied, nor were there significant differences in changes of these parameters within individual patients. CONCLUSIONS: Characteristics and parameters of mechanical ventilation are not influenced by the development of VAP. It is, therefore, unlikely that these variables are useful in the diagnostic work-up of VAP.

Case-Control Studies↗

PubMed2001

Resolution of infectious parameters after antimicrobial therapy in patients with ventilator-associated pneumonia.

Although recommended durations of antimicrobial therapy for ventilator-associated pneumonia (VAP) range from 7 to 21 d, these are not based on prospective studies and little is known about the resolution of symptoms after start of antibiotics. Resolution of these symptoms was investigated in 27 patients. VAP was diagnosed on clinical, radiographic, and microbiological criteria, including quantitative cultures of bronchoalveolar lavage. All patients received appropriate antibiotic therapy. Highest temperatures, leukocyte counts, Pa(O(2))/FI(O(2)) ratios, and semiquantitative cultures of endotracheal aspirates were recorded from start of therapy until Day 14. Resolution was defined as the first day that these parameters fulfilled the following definition: temperature < or = 38 degrees C, leukocytes < or = 10 x 10(9)/L, Pa(O(2))/FI(O(2)) ratio > or = 25 kPa, and no or +1 of bacterial growth of etiologic pathogens in cultures of endotracheal aspirate. VAP was caused by Enterobacteriaceae (n = 14), P. aeruginosa (n = 7), S. aureus (n = 6), H. influenzae (n = 3), and S. pneumoniae (n = 1). H. influenzae and S. pneumoniae were eradicated from tracheal aspirates, whereas Enterobacteriaceae, S. aureus, and P. aeruginosa persisted, despite in vitro susceptibility to antibiotics administered. Significant improvements were observed for all clinical parameters, most apparently within the first 6 d after start of antibiotics. Newly acquired colonization, especially with P. aeruginosa and Enterobacteriaceae, occurred in the second week of therapy. Six patients developed a recurrent episode of VAP, four of them with P. aeruginosa. Clinical responses to therapy for VAP occur within the first 6 d of therapy, endotracheal colonization with Gram-negative bacteria persists despite susceptibility to therapy, and acquired colonization usually occurs in the second week of therapy and frequently precedes a recurrent episode.

Adult↗

PubMed1998

Multiresistant bacteria as a hospital epidemic problem.

Since the introduction of antibiotics into clinical use, bacteria have protected themselves by developing antibiotic resistance mechanisms. Currently, there are increasing problems worldwide with multiresistant bacteria. These problems are especially evident within hospitals, where they frequently present as nosocomial epidemics. Currently, the most important nosocomial resistance problems on a global scale are caused by methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci and Enterobacteriaceae with plasmid-encoded extended-spectrum beta-lactamases. In this review we describe the characteristics of nosocomial epidemics of these three groups of multiresistant nosocomial pathogens. Despite the differences in bacterial species, the differences in mechanisms of resistance, the different ecological niches and the different infections caused by these pathogens, there are striking similarities in the variables determining nosocomial spread. The existence of each of these multiresistant micro-organisms and their concurrent spread seem to result from extensive antibiotic use and lapses in compliance with infection control measures. Problems with these bacteria became evident as monoclonal outbreaks, soon followed by establishment of endemicity especially in intensive care units. Finally, endemicity seems to be established on general hospital wards and in chronic care facilities and nursing homes, creating a continuous influx of colonized patients into special care wards. High compliance with infection control measures and a prudent and more restrictive use of antibiotics are the key measures to prevent these epidemics.

Cross Infection↗

PubMed1997

Duodenal diverticulitis.

The case history of a 56-year-old woman with an acute abdomen is presented. Laboratory data, a plain abdominal X-ray and ultrasound examination provided no clues for a definite diagnosis. Surprisingly, a duodenal diverticulitis was found at operation. Some aspects and complications of duodenal diverticula are discussed.

Diverticulitis↗

PubMed1992

[9-year experience with continuous ambulatory peritoneal dialysis in one center].

The experience gained with CAPD in a group of 101 patients with terminal renal failure and a subgroup of 19 patients with diabetes mellitus was analysed. The actuarial patient survival was 81% after two years and 50% after five years. The combined patient-technique survival after two years was 48.8%. The most important reasons for drop-out were transplantation (25%) and death (24%). Death was method-related in 4 patients and caused by peritonitis in 2 of them. More often peritonitis was the cause of morbidity and temporary interruption (10 x) or of permanent abandoning of the method (11 x ). The peritonitis frequency during the whole period of nine years was 1 : 11.3 months. Use of the Y-connector Twinbag system and a U.V.-light system reduced the incidence substantially. However, faecal peritonitis remains a dangerous situation which cannot be prevented in this way. The mortality in patients with diabetes mellitus is high but not method-related. The incidence of peritonitis is not significantly different from that among patients without diabetes mellitus.

Actuarial Analysis↗

PubMed1992

First dose hypotension after captopril; can it be predicted? A study of 240 patients.

We have studied prospectively the acute blood pressure lowering effect on an oral dose of captopril, 25 mg in 240 hypertensive patients. The mean relative reduction of systolic and diastolic BP was 16 and 15% respectively and the mean time to the mean arterial pressure nadir was 59 minutes. Systolic BP fell by more than 30% in 4.6% of patients and diastolic BP and mean arterial pressure dropped by more than 30% in 4.2 and 3.3% of patients respectively. Patients over 60 years of age showed a significantly larger fall in systolic and diastolic BP. Patients with renal artery stenosis reached the BP nadir in a significantly shorter time compared with patients with essential hypertension (50.5 vs. 59.7 minutes, P less than 0.05) and showed a significantly larger fall in systolic BP (20.7 vs. 15.4%, P less than 0.05). A forward stepwise regression analysis showed that only baseline plasma renin activity had a significant relation to the fall in BP (P less than 0.01, R = 0.57). We conclude that according to our definition of a greater than 30% decrease of the mean arterial pressure, a first dose hypotension after captopril was seen in 3.3% of 240 patients. Captopril treatment should be introduced carefully since not all those patients at risk of hypotension can be identified in advance.

Aldosterone↗