Clinically relevant potential drug-drug interactions in intensive care patients: A large retrospective observational multicenter study.

PURPOSE: Potential drug-drug interactions (pDDIs) may harm patients admitted to the Intensive Care Unit (ICU). Due to the patient's critical condition and continuous monitoring on the ICU, not all pDDIs are clinically relevant. Clinical decision support systems (CDSSs) warning for irrelevant pDDIs could result in alert fatigue and overlooking important signals. Therefore, our aim was to describe the frequency of clinically relevant pDDIs (crpDDIs) to enable tailoring of CDSSs to the ICU setting. MATERIALS & METHODS: In this multicenter retrospective observational study, we used medication administration data to identify pDDIs in ICU admissions from 13 ICUs. Clinical relevance was based on a Delphi study in which intensivists and hospital pharmacists assessed the clinical relevance of pDDIs for the ICU setting. RESULTS: The mean number of pDDIs per 1000 medication administrations was 70.1, dropping to 31.0 when considering only crpDDIs. Of 103,871 ICU patients, 38% was exposed to a crpDDI. The most frequently occurring crpDDIs involve QT-prolonging agents, digoxin, or NSAIDs. CONCLUSIONS: Considering clinical relevance of pDDIs in the ICU setting is important, as only half of the detected pDDIs were crpDDIs. Therefore, tailoring CDSSs to the ICU may reduce alert fatigue and improve medication safety in ICU patients.

[Fatal intoxication with nicotine for e-cigarette]. / Fatale intoxicatie met nicotine voor e-sigaret.

BACKGROUND: Since the introduction of the electronic e-cigarette a few years ago, its use has greatly increased. The liquid formulations used in these e-cigarettes contain nicotine in high concentrations; ingestion of these liquids can be fatal. CASE DESCRIPTION: A 42-year-old male was admitted to the Intensive Care ward due to cardiac arrest. The patient had ingested highly concentrated liquid nicotine, originating from a vial with liquid for e-cigarettes. When the ambulance personnel found the patient he did not have a pulse; following CPR and administration of adrenaline his pulse returned. Upon admission, the plasma nicotine level was high at 3.0 mg/l (reference values for a smoker are 0.01-0.05 mg/l) and the patient's neurological function was poor. The patient was treated symptomatically, but eventually died of a postanoxic encephalopathy. CONCLUSION: Nicotine e-liquids are highly concentrated. Intentional ingestion can lead to toxic levels of nicotine which are associated with cardiac arrhythmias or arrest. Because even a few millilitres can be lethal, nicotine intoxication due to e-liquid ingestion should be considered potentially life-threatening.

Survey into blood glucose control in critically ill adult patients in the Netherlands.

BACKGROUND: To study current clinical practice in blood glucose (BG) control in adult intensive care units (ICUs) in the Netherlands. METHODS: We performed a national survey focusing on blood glucose targets, insulin administration, BG control guidelines, and opinions regarding BG control aiming for normoglycaemia (known as intensive insulin therapy, IIT). RESULTS: The completed questionnaire was returned by 88/113 (78%) of the participating centres. In 98% (86/88) of the ICUs some sort of BG control was being practised. Half of the ICUs (42/86, 48%) used tight BG targets as with IIT; 28/86 (33%) and 13/86 (15%) used more liberal targets of 4.4 to 7.0 mmol/l and 4.4 to 8.0 mmol/l, respectively. Eighty-two (93%) reported having a local guideline on BG control (or IIT). The BG threshold to start insulin was 7.0+/-1.3 mmol/l vs 7.8+/-1.3 mmol/l in ICUs that practised IIT vs ICUs that practised less tight BG control, respectively (p=0.005). In 28/86 (33%) measurement of the BG values was done according to a strict time schedule (i.e., BG values were measured on predefined time points). While respondents were fairly agreed on the benefits of IIT, opinions regarding ease of implementation and time needed to apply this strategy varied. In addition, severe hypoglycaemia was considered a serious side effect of IIT. CONCLUSION: Approximately half of the ICUs in the Netherlands reported having implemented IIT. However, the full guideline as used in the original studies on IIT was hardly ever implemented. Concerns about severe hypoglycaemia, at least in part, hampers implementation of IIT.

[Spinal epidural abscess as a complication of a finger infection]. / Een spinaal epiduraal abces als complicatie van een ontstoken vinger.

An 81-year-old man was treated with intravenous antibiotics for a soft tissue infection in a finger. Despite adequate antibiotic treatment, he developed signs of spinal cord injury caused by a cervical spinal epidural abscess. An emergency laminectomy was performed. The neurological impairment appeared to be irreversible, and the patient died. Spinal epidural abscess is a rare and serious complication ofa bacteraemia. It is often caused by an infection of the skin or soft tissue with Staphylococcus aureus. Given the risk of rapidly progressive and irreversible neurological damage, this complication must be treated as soon as possible. The treatment of choice is surgery. Conservative management with intravenous antibiotics is an option only under strict conditions.

Intrusive growth of flax phloem fibers is of intercalary type.

Flax (Linum usitatissimum L.) phloem fibers elongate considerably during their development and intrude between existing cells. We questioned whether fiber elongation is caused by cell tip growth or intercalary growth. Cells with tip growth are characterized by having two specific zones of cytoplasm in the cell tip, one with vesicles and no large organelles at the very tip and one with various organelles amongst others longitudinally arranged cortical microtubules in the subapex. Such zones were not observed in elongating flax fibers. Instead, organelles moved into the very tip region, and cortical microtubules showed transversal and helical configurations as known for cells growing in intercalary way. In addition, pulse-chase experiments with Calcofluor White resulted in a spotted fluorescence in the cell wall all over the length of the fiber. Therefore, it is concluded that fiber elongation is not achieved by tip growth but by intercalary growth. The intrusively growing fiber is a coenocytic cell that has no plasmodesmata, making the fibers a symplastically isolated domain within the stem.

Novel approach to quantify immobilized-enzyme distributions.

The quantitative intraparticle enzyme distribution of Assemblase, an industrially employed polydisperse immobilized penicillin-G acylase, was measured. Because of strong autofluorescence of the carrier, the generally applied technique of confocal scanning microscopy could not be used; light microscopy was our method of choice. To do so, Assemblase particles of various sizes were sectioned, labeled with antibodies specifically against the enzyme, and analyzed light microscopically. Image analysis software was developed and used to determine the intraparticle enzyme distribution, which was found to be heterogeneous, with most enzyme located in the outer regions of the particles. Larger particles showed steeper gradients than smaller ones. A mathematical representation of the intraparticle profiles, based on in-stationary enzyme diffusion into the particles, was validated successfully for a broad range of particle sizes using data for volume-averaged particle size and enzyme loading. The enzyme gradients determined in this work will be used as input for a physical model that quantitatively describes the complex behavior of Assemblase. Such a physical model will lead to identification of the current bottlenecks in Assemblase and can serve as a starting point for the design of improved biocatalysts that also may be based on intelligent use of enzyme gradients.

Temporal and tissue-specific expression of the tobacco ntf4 MAP kinase.

The large number of mitogen-activated protein (MAP) kinase genes identified to date in plants suggests that their encoded proteins have a wide array of functions in development and physiological responses, as has been indicated by studies on the factors which lead to the activation of these kinases. Signalling pathways involving members of a multigene family employ a variety of mechanisms to ensure response specificity, one of which is via differential gene expression. We have performed detailed analyses of the expression of the tobacco ntf4 MAP kinase gene using a variety of approaches. The ntf4 gene promoter region was isolated and a chimeric ntf4 promoter-GUS fusion construct was introduced into plants. GUS expression was detected in pollen, in developing and mature embryos, and shortly after seed germination, but not in other floral tissues and tissues such as leaf, root, or stem. This expression pattern was confirmed by northern and western analyses. In situ hybridization and immunolocalization studies showed that the expression of the ntf4 gene and its encoded protein p45Ntf4 occurred in embryos at least from the globular embryo stage until the mature seed, as well as in the seed endosperm. Taken together, the results show that the p45Ntf4 MAP kinase has a very restricted expression pattern, being found only in pollen and seeds. These findings should be important when considering MAP kinase function in plants.

Meropenem versus cefuroxime plus gentamicin for treatment of serious infections in elderly patients.

In this multicenter study, the efficacy of and tolerability for meropenem were compared with those for the combination of cefuroxime-gentamicin (+/- metronidazole) for the treatment of serious bacterial infections in patients > or = 65 years of age. A total of 79 patients were randomized; thirty-nine received meropenem (1 g/8 h), and 40 received cefuroxime (1.5 g/8 h) plus gentamicin (4 mg/kg of body weight daily) for 5 to 10 days. Metronidazole (500 mg/6 h) could be added to the cefuroxime-gentamicin regimen for the treatment of intra-abdominal infections (n = 10). Seventy patients were evaluable for clinical efficacy; the primary diagnoses were as follows: pneumonia in 41 patients (20 treated with meropenem, 21 treated with cefuroxime-gentamicin), intra-abdominal infection in 10 patients (7 meropenem, 3 cefuroxime-gentamicin-metronidazole), urinary tract infection (UTI) in 11 patients (6 meropenem, 5 cefuroxime-gentamicin), sepsis syndrome in 7 patients (4 meropenem, 3 cefuroxime-gentamicin), and "other" in 1 patient (cefuroxime-gentamicin). The pathogens isolated from 18 patients with bacteremia were as follows: Staphylococcus spp. (n = 2), Streptococcus spp. (n = 2), members of the family Enterobacteriaceae (n = 11), and Bacteroides spp. (n = 3). A satisfactory clinical response at the end of therapy was achieved in 26 of 37 (70%) and 24 of 33 (73%) evaluable patients treated with meropenem and combination therapy, respectively. Clinical success was achieved in 23 of 31 (74%) and 21 of 28 (75%) evaluable patients with infections other than UTIs, respectively. A satisfactory microbiological response occurred in 15 of 22 (68%) patients in the meropenem group compared with 12 of 19 (63%) treated with combination therapy. Renal failure occurred during therapy in 2 of 39 (5%) meropenem recipients compared with 5 of 40 (13%) of those treated with combination therapy. The findings in this small study indicate that meropenem is as efficacious for and as well tolerated by elderly patients as the combination of cefuroxime-gentamicin (+/- metronidazole).

Cefepime compared with ceftazidime as initial therapy for serious bacterial infections and sepsis syndrome.

In an open randomized multicenter comparative study, we evaluated the safety and efficacy of cefepime (CP; 2.0 g given intravenously every 12 h) and ceftazidime (CZ; 2.0 g given intravenously every 8 h) as initial treatment for adult patients with suspected serious bacterial infections. A total of 133 patients entered the study, of whom 114 were evaluable for clinical and microbiological response assessment: 56 received CP and 58 received CZ. About 50% (30 who received CP and 25 who received CZ) fulfilled the criteria of the sepsis syndrome. The treatment groups were comparable with respect to sex distribution, mean age, underlying diseases, treatment duration, APACHE II score, and type of infection. The most commonly cultured microorganisms were members of the family Enterobacteriaceae, Streptococcus pneumoniae, and Staphylococcus aureus. The causative microorganisms were eradicated from 92% (37 of 40) of patients with a microbiologically documented infection who underwent treatment with CP; they were eradicated from 86% (42 to 49) of patients who received CZ. The responses of only clinically documented infections in the CP group were 90% (27 of 30 patients); in the CZ group they were 87% (26 of 30 patients). When patients fulfilled the criteria of the sepsis syndrome (septic shock excluded), the causative microorganisms were eradicated from 89% (16 of 18) of CP-treated patients and 86% (12 of 14) of CZ-treated patients. None of these differences was statistically significant. Mortality was the same in both groups (four patients in each group) and was not attributable to the study medication. In conclusion, CP is at least as effective and as safe as CZ, as initial antimicrobial therapy for suspected serious bacterial infections in nonneutropenic patients with or without the sepsis syndrome. CP has the additional advantage in that it can be given twice daily, which may lead to a decrease in hospital costs.

Pharmacokinetics of cefepime in patients with the sepsis syndrome.

We investigated the pharmacokinetics of cefepime after administration of multiple doses to seven patients with the sepsis syndrome. Patients ranged in age from 66 to 78 years (mean +/- S.D.: 74 +/- 5 years); all fulfilled the criteria of the sepsis syndrome and had APACHE-II scores between 14 and 21 (mean +/- S.D.: 17 +/- 2). Serial blood and urine samples were collected after a minimum of 3 days (steady state) of treatment with cefepime 2.0 g bd i.v. Cefepime was assayed by HPLC. Data were analysed using non-compartmental methods. The mean +/- S.D. creatinine clearance (Clcr) was 55 +/- 8 mL/min. Mean +/- S.D. values for selected pharmacokinetic parameters on day 5 were Cmax (94.2 +/- 23.9 mg/L), T1/2 (3.4 +/- 1.1 h), Vdss (32.6 +/- 17.5 L), and the total clearance Cl(total) (125 +/- 51 mL/min). Time to peak plasma concentration (Tmax) and area under curve (AUC) averaged 0.7 +/- 0.2 h and 305 +/- 115 mg.h/L, respectively. Cefepime plasma concentrations were above the MIC90 for Pseudomonas aeruginosa (7 mg/L) for approximately 80% of the time and in the case of Enterobacteriaceae (0.5 mg/L) for 100% of the time. The more prolonged T1/2 in comparison with young healthy volunteers (T1/2 = 2.1 h) is consistent with the changes in renal function associated with increased age, and is comparable to data obtained in healthy elderly subjects (T1/2 = 3.7 h). Cmax, AUC and Cl(tot) were more variable than those observed in previous studies and are probably a reflection of the clinical conditions under which dosing and sampling occurred.

International comparative study of cefepime and ceftazidime in the treatment of serious bacterial infections.

In this randomized multicentre study, we compared the safety and efficacy of cefepime, 2.0 g bd i.v., with that of ceftazidime, 2.0 g tid i.v., as initial treatment of adult patients with serious infections of bacterial aetiology. Three hundred and forty-eight patients were entered into the study, 173 received cefepime and 175 ceftazidime. The treatment groups were comparable with respect to demographic characteristics, including the types of infection (cefepime/ceftazidime: urinary tract, 55/72; lower respiratory tract, 83/74; skin and soft tissue, 23/14; septicaemia, 81/81; and others, 15/5). Gram-positive bacteria were identified as pathogens on 86 occasions (cefepime/ceftazidime: 48/41), including 20 Staphylococcus aureus isolates (13/7) and 27 Streptococcus pneumoniae isolates (14/13). Gram-negative bacilli were isolated on 261 occasions (126/135), and included 219 Enterobacteriaceae (cefepime/ceftazidime: 108/111) and 34 strains of Pseudomonas aeruginosa (14/20). An intention-to-treat analysis revealed satisfactory clinical response rates of 80% and 79% for the cefepime and ceftazidime groups, respectively, and bacteriological eradication rates of 85% and 88% for the cefepime and ceftazidime groups, respectively. Of patients with microbiologically documented infections, 86% (84 of 98) treated with cefepime and 87% (94 of 108) treated with ceftazidime responded satisfactorily. Thirty-two patients (19%) treated with cefepime and 26 (15%) treated with ceftazidime died. Thirty-six patients in the cefepime group and 23 in the ceftazidime group experienced adverse events; therapy was discontinued prematurely in four and two patients in the cefepime and ceftazidime groups, respectively. Of the patients experiencing adverse events, 22 (13%) treated with cefepime developed intolerance at the injection site, compared with 11 (6%) treated with ceftazidime (P = 0.045). In conclusion, twice-daily cefepime (2 g bd) is at least as effective as ceftazidime (2 g tid), as initial empirical therapy for serious bacterial infections in non-neutropenic patients.

The sepsis syndrome in a Dutch university hospital. Clinical observations.

BACKGROUND: Most studies of the cause of sepsis syndrome focus on patients hospitalized in intensive care units. In this study, we analyzed the incidence, cause, and outcome of the sepsis syndrome in all hospitalized patients. METHODS: Clinical and microbiologic data were obtained for 382 patients (5.6% of all patients admitted) from whom blood was drawn for culture. RESULTS: The incidence of the sepsis syndrome was 13.6 per 1000 patients admitted (1.06 per 1000 hospital days), while the incidence of septic shock was 4.6 per 1000. The respiratory tract was the predominant infection site. Of all patients with sepsis syndrome, 38% (n = 35) had positive blood cultures. More than half of these cultures (13 [57%]) were caused by gram-positive microorganisms (excluding patients receiving selective decontamination of the digestive tract and those with intravascular device-related bacteremias). The mortality for patients with sepsis syndrome without shock was 28% (17/61), while for patients with septic shock, it was 55% (17/31). Patients with cardiovascular diseases had a significantly (P < .005) greater risk of dying during a sepsis syndrome episode than patients with other predisposing factors. Multivariate analysis of factors influencing outcome identified the development of shock and an immunocompromised state as being significantly associated with outcome in patients with sepsis syndrome. CONCLUSIONS: Patients fulfilling the criteria for the sepsis syndrome are at great risk of developing septic shock or multiple-organ failure and subsequently dying. In our hospital, the majority of bacteremic episodes were associated with gram-positive microorganisms.

Histological comparison of single somatic embryos of maize from suspension culture with somatic embryos attached to callus cells.

An embryogenic suspension culture of Zea mays, genotype 4C1, was obtained from friable callus that was cultured on solid medium and had been obtained from zygotic embryos. The suspension contained non-dividing elongated cells, clusters of dividing isodiametric cells, and globular, ovoid, and polar stages of somatic embryos. The single somatic embryos were blocked in shoot meristem formation: when transferred to regeneration medium they developed a root and, at the shoot side, a green cap with meristematic cells, but a scutellum and leaf primordia were not formed. In medium containing 2,4-dichlorophenoxy acetic acid, somatic embryos formed embryogenic callus aggregates, consisting of globular stage somatic embryos attached to each other via undifferentiated callus cells. These somatic embryos developed into mature embryos with the zygotic histological characteristics, such as scutellum and leaf primordia, in maturation medium, and then regenerated into plants in regeneration medium. By omitting the maturation phase, regeneration occurred via organogenesis. Polyembryos, i. e. embryos attached to each other without callus tissue in between, behaved as single somatic embryos. It is concluded that the attached callus tissue provides a factor that stimulates scutellum and leaf primordia formation.

Structure and function of the microtubular cytoskeleton during pollen development in Gasteria verrucosa (Mill.) H. Duval.

In a study of pollen development in Gasteria verrucosa, the changes in the spatial organization of microtubules were related to the processes of cell division, nuclear movement and cytomorphogenesis. Sections of polyethylene-glycol-embedded anthers of G. verrucosa were processed immunocytochemically to record the structure and succession of fluorescently labeled microtubular configurations. Using microspectrophotometric measurements the relative quantity of tubulin in microtubules per unit of cytoplasm was determined. Cell dimensions and nuclear positions were measured to relate changes in cell shape and nuclear movements to microtubular configurations. Microtubules were detected in the different cells during microsporogenesis and microgametogenesis. In microspore mother cells which are approximately isodiametric at interphase, microtubules were predominantly arranged in a criss-cross pattern. The microtubules probably function as a flexible cytoskeleton which sustains the integrity of the cytoplasm. Bundles of microtubules were observed in the microspores, in the generative cells and during nuclear division, where they functioned in establishing and maintaining cell and spindle shapes. Microtubules radiating from nuclear membranes appeared to fix the nucleus in position. In prophase of meiosis and after microspore mitosis, periods a high fluorescence intensity were distinguished indicating a variation in the quantity of microtubules.