Impact of a comprehensive safety initiative on patient-controlled analgesia errors.

BACKGROUND: Adverse drug events related to patient-controlled analgesia (PCA) place patients at risk. METHODS: We reviewed all critical incident reports at three tertiary care hospitals dated January 1, 2002, to February 28, 2009. In this longitudinal cohort study, critical incidents attributable to PCA errors were identified, and each incident was investigated. A safety intervention was implemented in February 2006 and involved new PCA pumps, new preprinted physician orders, nursing and patient education, a manual independent double-check, and a formal nursing transfer of accountability. RESULTS: A total of 25,198 patients were treated with PCA during this study, and 62 errors were found (0.25%), with 21 (0.08%) involving pump programming. All errors occurred before the safety interventions were put in place. Compared with the preintervention period, the odds ratio of a PCA error postintervention was 0.28 (95% CI = 0.14, 0.53; P < 0.001) whereas the odds ratio of a pump-programming error postintervention was 0.05 (95% CI = 0.001, 0.30; P < 0.001). Programming the wrong drug concentration was the most common programming error (10 of 21). Improper setup of intravenous tubing was also common (8 of 62), with one incident leading to respiratory arrest. Most PCA errors resulted in no harm, but there was negative impact to patients 34% of the time. CONCLUSION: At less than 1%, the incidence of PCA errors is relatively low. Most errors occur during PCA administration. Safety can be improved by addressing equipment, education, and process issues.

Recent development of antitumor agents from Chinese herbal medicines. Part II. High molecular compounds(3).

High molecular compounds from Chinese herbal medicines, including ribosome-inactivating proteins and polysaccharides from both fungi and high plants have been tested for the treatment of malignant diseases. Polysaccharides possessing immunostimulating activities can be used as adjuvants in tumor treatment. The fungi containing such polysaccharides are usually edible mushrooms or tonics in Traditional Chinese Medicine. Parts from high plants such as Radix Astragali and Fructus Lycii containing polysaccharides are mainly used as tonic in Traditional Chinese Medicine. Ribosome-inactivating proteins are a group of proteins exerting cytotoxic activities via inhibition of protein synthesis. Some of the ribosome-inactivating proteins have been used as the cytotoxic part in conjugates with monoclonal antibodies as tumor-targeting drugs. The cytotoxic and antineoplastic mechanisms of the high molecular compounds are rather different from those of the low molecular compounds described in part I.

Recent development of antitumor agents from chinese herbal medicines; part I. Low molecular compounds.

A series of low molecular compounds from Chinese herbal medicines which have proved to be, in some cases, highly effective especially in tumor therapy, is listed here (part II will deal with high molecular compounds, to be published in the next issue). In contrast to synthetic agents used in cancer chemotherapy, these natural compounds have relatively low toxicities. Many of the clinical studies referred to in this paper have been carried out on Asians. Because genetic factors influence enzyme levels, sometimes leading to striking differences in metabolism and pharmacokinetics of drugs, results obtained in clinical studies carried out in China are not 100 % transferable to the European population. The mechanisms of action of these compounds are manifold, consisting of reactions with DNA bases, intercalation in DNA, inhibition of topoisomerases, inhibition of protein kinases, induction of apoptosis etc. Some of the compounds have interesting structural features, that may be used as lead structures for the development of further antitumor agents.

Induction of poly(ADP-ribosyl)ation and DNA damage in human peripheral lymphocytes after treatment with (-)-epigallocatechin-gallate.

With regard to a future use of tea polyphenols in intervention trials with individuals at high cancer risk, the effects of the tea ingredient (-)-epigallocatechin gallate (EGCG) on poly(ADP-ribose) (PAR) levels and on DNA damage were investigated in human lymphocytes. A dose- and time-dependent elevation of both PAR formation as assessed by quantitative immunofluorescence analysis and DNA damage as assessed by the comet assay were observed after treatment with EGCG at 20, 40 and 80 microM for 10-240 min. Maximum levels of PAR formation and of DNA damage were observed after 10 min at all concentrations tested. Increased PAR levels were still detectable by 240 min in the 40 and 80 microM groups. At the lowest concentration, which is near the physiological peak values found after tea ingestion, PAR formation was not correlated with DNA damage. Here, EGCG led to pronounced PAR levels, whereas the comet assay was almost negative. In contrast, such marked differences in time course and extent of both genotoxicity and PAR formation following EGCG treatment were not detected after gamma-irradiation. Our results suggest that the known chemopreventive effects of EGCG, the main constituent of tea, may be partly attributed to an induction of PAR formation.

[Cancer prevention with green tea: reality and wishful thinking]. / Krebsprävention durch grünen Tee: Wirklichkeit und Wunschdenken.

Different processing of the leaves of the tea plant Camellia sinensis yields green or black tea, the subject of numerous investigations on the preventive effects on chronic degenerative diseases. The tea polyphenols, in particular (-)-epigallocatechin gallate (EGCG) were found to account for most of the protective effects. Since the concentration of EGCG is 5 times higher in green than in black tea, it is assumed that green tea possesses a greater preventive potential. Protection against cancer and cardiovascular diseases are the most important biomedical effects. In experimental models the preventive activity of tea is well documented for tumors at many organ sites. In humans, tea was reported to be protective against tumors of the lung, the gastrointestinal tract and the liver. Tea polyphenols, especially EGCG, were shown to exert cancer-protective activity by the following mechanisms: they inhibit the metabolic activation of carcinogens and induce at the same time detoxifying enzymes. They inhibit signaling pathways controlling cell proliferation and tumor growth such as protein kinase C and the release of tumor necrose factor-alpha from cells. Tea polyphenols reactivate processes which are impaired in tumor cells, such as the programmed cell death and the tumorsuppressor gene p53. Finally, tea polyphenols can also block angiogenesis leading to a starvation of the tumor. By inactivation of proteolytic enzymes they inhibit the development of metastases. This short review summarizes relevant recent findings on the protective effects of green tea constituents.