QCD and strongly coupled gauge theories: challenges and perspectives.

We highlight the progress, current status, and open challenges of QCD-driven physics, in theory and in experiment. We discuss how the strong interaction is intimately connected to a broad sweep of physical problems, in settings ranging from astrophysics and cosmology to strongly coupled, complex systems in particle and condensed-matter physics, as well as to searches for physics beyond the Standard Model. We also discuss how success in describing the strong interaction impacts other fields, and, in turn, how such subjects can impact studies of the strong interaction. In the course of the work we offer a perspective on the many research streams which flow into and out of QCD, as well as a vision for future developments.

Computer aided surgical reconstruction after complex facial burn injuries -- opportunities and limitations.

In severe facial burn injuries with extensive destruction of anatomical structures, cosmetic and functional outcome of treatment are frequently not satisfactory. Although operative therapy is being continuously refined, the variety and proximity of structures in the facial region is considered a major challenge in reconstructive surgery. We present the case of a 16-year-old patient with a severe facial burn injury. In planning the reconstructive procedures, we used a multimodal approach employing data from computerized tomography imaging, as well as from surface laser scanning, which provided three-dimensional visualization of facial soft tissues. Amount and pattern of structural loss could thus be determined more precisely and studied more vividly than by inspection of two-dimensional imaging alone. Anatomical features to be reconstructed could be projected onto the skin area of the prelaminated vertical rectus abdominis muscle (VRAM) flap that has been chosen to cover the defect. Prior to surgery, correction of the defects was simulated and the results of the virtual procedure superimposed on a three-dimensional head model of the patient. Tissue elasticity and thickness of the flap, however, could not be ascertained in advance, indicating the limitations of the method.

Effects of standardized acute normovolemic hemodilution on intraoperative allogeneic blood transfusion in patients undergoing major maxillofacial surgery.

The aim of the present study was to demonstrate the practicality and efficacy of acute normovolemic hemodilution (ANH) to reduce allogeneic red blood cell (RBC) transfusion in patients undergoing elective surgery with anticipated high intraoperative blood loss (BL). 124 patients (age 48 +/- 18 years, ASA classes I-III) underwent major maxillofacial surgery in a university hospital (68% tumor surgery, 32% dysgnathia correction). After induction of general anesthesia, ANH was performed by standardized withdrawal of 900 ml (2 units) of whole blood and simultaneous infusion of 500 ml of hydroxyethyl starch solution (6% HES 130,000/0.4) and 1500 ml of crystalloidal solution. Intraoperative BL was fluid-compensated until physiologic parameters indicated the need for RBC transfusion. First, autologous ANH-blood was retransfused followed by, if necessary, allogeneic RBC. Total BL was referred to the patient's calculated blood volume (BV): fractional blood volume loss, BL(fract) = BL/BV. ANH took 16 +/- 2 min and was void of any adverse event. The costs for ANH was 24 per patient. 55 patients had a mean BL(fract) of 44 +/- 28% and required an intraoperative transfusion; 49/55 patients with an average BL(fract) of 37 +/- 14% were transfused with only autologous ANH-blood; 6/55 patients with a mean BL(fract) of 100 +/- 47% underwent additional transfusion with allogeneic RBC. Standardized, 2 unit, ANH is a practicable, safe and economic blood conservation technique that allowed for the complete avoidance of allogeneic RBC transfusion in 89% of patients undergoing maxillofacial surgery that required an intraoperative RBC transfusion.

[18F]FDG imaging of head and neck tumours: comparison of hybrid PET and morphological methods.

The aim of this study was to evaluate fluorine-18 fluorodeoxyglucose ([(18)F]FDG) imaging of head and neck tumours using a second- or third-generation hybrid PET device. Results were compared with the findings of spiral computed tomography (CT) and magnetic resonance imaging (MRI), and, as regards lymph node metastasis, the ultrasound findings. A total of 116 patients with head and neck tumours (83 males and 33 females aged 27-88 years) were examined using a hybrid PET scanner after injection of 185-350 MBq of [(18)F]FDG (Picker Prism 2000 XP-PCD, Marconi Axis gamma-PET(2) AZ). Hybrid PET examinations were performed in list mode using an axial filter. Reconstruction of data was performed iteratively. Ninety-six patients underwent CT using a multislice technique (Siemens Somatom Plus 4, Marconi MX 8000), 18 patients underwent MRI and 100 patients were examined by ultrasound. All findings were verified by histology, which was considered the gold standard, or, in the event of negative histology, by follow-up. Correct diagnosis of the primary or recurrent lesion was made in 73 of 85 patients using the hybrid PET scanner, in 50 of 76 patients on CT and in 7 of 10 patients on MRI. Hybrid PET successfully visualised metastatic disease in cervical lymph nodes in 28 of 34 patients, while 23 of 31 were correctly diagnosed with CT, 3 of 4 with MRI and 30 of 33 with ultrasound. False positive results regarding lymph node metastasis were seen in three patients with hybrid PET, in 14 patients with CT and in 13 patients with ultrasound. MRI yielded no false positive results concerning lymph node metastasis. In one patient, unrecognised metastatic lesions were seen on hybrid PET elsewhere in the body (lung: n=1; bone: n=1). Additional malignant lesions at sites other than the head and neck tumour were found in three patients (one patient with lung cancer, one patient with pelvic metastasis due to a carcinoma of the prostate and one patient with pulmonary metastasis due to breast cancer). It is concluded that [(18)F]FDG PET with hybrid PET scanners is superior to CT and MRI in the diagnosis of primary or recurrent lesions as well as in the assessment of lymph node involvement, whereas it is inferior to ultrasound in the detection of cervical lymph node metastasis.

[Positioning of the premaxilla in cases of bilateral cleft lip, alveolus and palate using Latham's appliance]. / Positionierung der Oberkieferelemente mit der Latham-Appartur bei Patienten mit Lippen-Kiefer-Gaumen-Spalten.

UNLABELLED: SUBJECT MATTER: In cases of bilateral cleft lip, alveolus and palate, preoperative positioning of the premaxilla using Latham's appliance has been described. This method is controversial, since it may cause growth defects. PATIENTS AND METHODS: From 1992 to 2000, Latham's appliance was inserted preoperatively into 20 patients with bilateral lip, alveolus and palate clefts with extreme premaxillary protrusion. Pin fixation ensued at the age of 3 months. After adjustment of the premaxilla, the soft palate was closed and bilateral lip adhesion as well as bilateral gingivoperiosteoplasty were performed directly after the removal of the appliance. Final lip closure took place 4-6 weeks later. At the age of 2 years, the hard palate was closed. Evaluation was based on combined face-maxilla models, standard photographs and, when available, lateral skull x-rays showing the relative position of the segments, the influence of Latham's appliance on the nasal septum and the relation of the upper jaw to the skull base and mandibula. RESULTS: In all cases, a satisfactory alveolar alignment was achieved; thickening and curvature of the nasal septum occurred but receded. Neither growth disturbances nor dental germ damage were seen. In two cases, complications arose from suture dehiscence of the lip adhesion: in one patient, a screw defect caused a loosening of the appliance and there was also a transmigration of the postpremaxillary pin. CONCLUSIONS: On the basis of our experience, the use of Latham's appliance, combined with consistent orthodontic supervision and, if necessary, treatment, represents a practical option for the treatment of bilateral cleft lip, alveolus and palate, especially in cases with extreme protrusion of the premaxilla.

[Giant hemangioma of the tongue: combined use of perioperative blood conservation procedures]. / Riesenhämangiom des Zungenkörpers Kombinierter Einsatz fremdblutsparender Verfahren zur perioperativen Reduktion von Fremdbluttransfusionen.

A giant hemangioma of the tongue was resected in a 16-year-old otherwise healthy young man (ASA I). Despite a total blood loss of 4,300 ml, corresponding to 105% of the patients intravascular blood volume, no allogeneic red blood cells had to be transfused intraoperatively. Besides minimization of intraoperative blood loss with preoperative alcohol injections into the tumor, ligation of large tumor-perfusing arteries, application of fibrin glue, skillful surgical technique, positioning of the surgical field above the level of the heart, controlled hypotension and maintenance of normothermia, acute normovolemic hemodilution (augmented by preoperative administration of recombinant human erythropoetin - rhEpo) and autotransfusion of lost blood were used for recovery of autologous blood. Under the protection of hyperoxia, a decrease of the hemoglobin (Hb) concentration to 4.2 g/dl was bridged by extreme normovolemic hemodilution. No signs of immanent or manifest tissue hypoxia were encountered. Retransfusion of autologous red blood cells was only started when surgical control of bleeding was achieved. Additionally a total of 4 units of fresh frozen plasma were infused for stabilization of plasma coagulation. After a 9-hour surgical duration, the patient was transferred to the intensive care unit, normotensive (with low-dose infusion of norepinephrin) and normothermic with a Hb concentration of 5.6 g/dl. In the face of an increasing lactacidosis 2 units of packed red blood cells were transfused on post surgical day 1.

[Clinical and epidemiological data of patients with malignomas of the head and neck]. / Klinische und epidemiologische Daten zu Malignomen des Kopf-Hals-Bereichs.

BACKGROUND: The present study describes clinical and epidemiological data of patients with malignomas of the head and neck documented in the Munich Cancer Register. PATIENTS AND METHODS: Data of head and neck cancer patients treated at four departments of head and neck surgery and one of oral-maxillo-facial surgery in the area of Munich from 1978 up to now are reported. RESULTS: Incidence and mortality as a function of age, sex, and tumor localization are described in comparison to clinical and epidemiological data as specified in tumor registers of the Saarland and the USA. Moreover, TNM stages, survival, recurrence, and metastasis rates are presented. CONCLUSION: Based on the documentation of the Munich Cancer Register our study is the first to present a detailed description of clinical and epidemiological data of patients suffering from head and neck malignomas.

[[F-18]FDG imaging of head and neck tumors: comparison of hybrid PET, dedicated PET and CT]. / [F-18]FDG-Bildgebung bei Kopf-Hals-Tumoren: vergleichende Untersuchungen mit Hybrid-PET, Ring-PET und CT.

AIM: Aim of the study was to evaluate [F-18]FDG imaging of head and neck tumors using a Hybrid-PET device of the 2nd or 3rd generation. Examinations were compared to dedicated PET and Spiral-CT. METHODS: 54 patients suffering from head and neck tumors were examined using dedicated PET and Hybrid-PET after injection of 185-350 MBq [F-18]FDG. Examinations were carried out on the dedicated PET first followed by a scan on the Hybrid-PET. Dedicated PET was acquired in 3D mode, Hybrid-PET was performed in list mode using an axial filter. Reconstruction of data was performed iteratively on both, dedicated PET and Hybrid-PET. All patients received a CT scan in multislice technique. All finding have been verified by the goldstandard histology or in case of negative histology by follow up. RESULTS: Using dedicated PET the primary or recurrent lesion was correctly diagnosed in 47/48 patients, using Hybrid-PET in 46/48 patients and using CT in 25/48 patients. Metastatic disease in cervical lymph nodes was diagnosed in 17/18 patients with dedicated PET, in 16/18 patients with Hybrid-PET and in 15/18 with CT. False positive results with regard to lymph node metastasis were seen with one patient for dedicated PET and Hybrid-PET, respectively, and with 18 patients for CT. In a total of 11 patients unknown metastatic lesions were seen with dedicated PET and with Hybrid-PET elsewhere in the body. Additional malignant disease other than the head and neck tumor was found in 4 patients. CONCLUSION: Using Hybrid-PET for [F-18]FDG imaging reveals a loss of sensitivity and specificity of about 1-5% as compared to dedicated PET in head and neck tumors. [F-18]FDG PET with both, dedicated PET and Hybrid-PET is superior to CT in the diagnosis of primary or recurrent lesions as well as in the assessment of lymph node involvement.

Serum and urine concentrations of flunitrazepam and metabolites, after a single oral dose, by immunoassay and GC-MS.

A clinical study was conducted to assess the ability of commercially available immunoassays to detect flunitrazepam (FNP) in plasma and urine samples and to compare the results with those obtained by gas chromatography-mass spectrometry (GC-MS). The clinical study consisted of four individuals (two male and two female) who had taken a single 2-mg dose of FNP. Serum was collected over a 48-h period and urine was collected over a 72-h period. The serum and urine samples were analyzed by the COBAS INTEGRA Serum Benzodiazepines assay (SBENZ), the TDx serum and urine Benzodiazepines assay, and GC-MS. The GC-MS procedure was developed for analysis of FNP and metabolites in plasma and urine using an acid hydrolysis step resulting in the formation of specific benzophenones corresponding to FNP and its metabolites. The relative sensitivities of the assays for the detection of FNP and metabolites in serum and urine were GC-MS > SBENZ > TDx. The immunoassay results for serum samples showed peak concentrations of FNP metabolites at 8 h after FNP ingestion for three individuals and at about 1 h for the fourth individual. The GC-MS, SBENZ, and TDx urine immunoassays detected drug above the stated limit of detection (LOD) in 44, 41, and 35 serial FNP urine samples, respectively. FNP metabolites were detected in urine samples with all three assays for up to 72 h after a 2-mg dose. The improved detection rate with the SBENZ assay as compared to the TDx assay is likely explained by its higher cross-reactivity with the major metabolite, 7-amino-flunitrazepam (7-amino-FNP), and its lower LOD.

New fluorescence polarization immunoassays for analysis of barbiturates and benzodiazepines in serum and urine: performance characteristics.

The performance of the new fluorescence polarization immunoassay reagents Cassette COBAS INTEGRA Serum Benzodiazepines assay (SBENZ) and Cassette Serum Barbiturates assay (SBARB) was evaluated as compared to other immunoassays (Abbott TDx Serum Benzodiazepines, Abbott TDx Urine Benzodiazepines, Behring EMIT Serum Benzodiazepines, Abbott ADx Serum Barbiturates, Behring EMIT Serum Barbiturates, and the COBAS INTEGRA Barbiturates (BARB) urine assay) and gas chromatography-mass spectrometry (GC-MS). Recoveries of nordiazepam and secobarbital using the SBENZ and SBARB assays, respectively, were equivalent for serum, plasma, and urine. Cross-reactivities of structurally related benzodiazepines, barbiturates, and their metabolites were very similar in serum and urine for the SBENZ and SBARB assays. Precision was within 5.4% for SBENZ serum and within 11% from 10 to 100 ng/mL for urine. Precision was within 5% for SBARB serum and within 7% from 136 to 277 ng/mL for the urine application. The standard curves for SBENZ and SBARB were stable for at least 16 weeks with the reagents stored open on the COBAS INTEGRA analyzer. Clinical comparison of the SBENZ serum assay indicated an increased pickup rate, as confirmed by GC-MS, compared to TDx and EMIT. The diagnostic sensitivities of the SBENZ serum application, TDx, and EMIT versus GC-MS were 100%, 89%, and 36%, respectively. The diagnostic specificities were 71%, 79%, and 100%, respectively. The diagnostic sensitivities of the SBENZ urine application and TDx versus GC-MS were 100% and the diagnostic specificities were 88%. The increased positive pick-up of the SBENZ assay compared to the other immunoassays is most probably due to the difference in the limit of detection (LOD) and the increased cross-reactivity for the low-dose benzodiazepines. Clinical comparison of the SBARB serum assay indicated an increased positive pick-up rate, as confirmed by GC-MS. The diagnostic sensitivities of the SBARB serum application, ADx, and EMIT versus GC-MS were 96%, 65%, and 35%, respectively. The diagnostic specificities were all 100%. The diagnostic sensitivities for the SBARB urine application and BARB versus GC-MS were all 100%, and the diagnostic specificities were all 91%. The SBENZ and SBARB kits demonstrated increased sensitivity for the detection of benzodiazepines and barbiturates in both serum and urine compared to the other immunoassays.

Oximetry of retinal vessels by dual-wavelength imaging: calibration and influence of pigmentation.

A method for noninvasive measurement of Hb O2 saturation (SO2) in retinal blood vessels by digital imaging was developed and tested. Images of vessels were recorded at O2-sensitive and O2-insensitive wavelengths (600 and 569 nm, respectively) by using a modified fundus camera with an image splitter coupled to an 18-bit digital camera. Retinal arterial SO2 was varied experimentally by having subjects breathe mixtures of O2 and N2 while systemic arterial SO2 was monitored with a pulse oximeter. Optical densities (ODs) of vascular segments were determined using a computer algorithm to track the path of reflected light intensity along vessels. During graded hypoxia the OD ratio (ODR = OD600/OD569) bore an inverse linear relationship to systemic SO2. Compensation for the influence of choroidal pigmentation significantly reduced variation in the arterial SO2 measurements among subjects. An O2 sensitivity of 0.00504 +/- 0.00029 (SE) ODR units/%SO2 was determined. Retinal venous SO2 at normoxia was 55 +/- 3.38% (SE). Breathing 100% O2 increased venous SO2 by 19.2 +/- 2.9%. This technique, when combined with blood flow studies in human subjects, will enable the study of retinal O2 utilization under experimental and various disease conditions.

[3-D imaging of the facial surface by topometry using projected white light strips]. / 3D-Erfassung der Gesichtsoberfläche durch Topometrie unter der Verwendung von projizierten Weisslichtstreifen.

Three-dimensional registration of the facial surface by methods which are currently in use is difficult because of the long measuring times required by point-based imaging systems. Artifacts caused by movement appear, e.g., blinking. Also the production of a facial plaster-cast model for measuring is not an adequate solution. In order to acquire data of the facial surface in a contact-free manner, a system is needed that has short measuring times, is able to record data of complex surfaces and at the same time does no harm to the open eyes. The method described here represents a new development of an industrial high tech CAD/CAM system. Unlike customary point-based imaging systems, the stripe projection method works using entire planes. Structured light is aimed at the surface to be measured, recorded by videocamera and calculated by triangulation; then the different views are combined by computer. The system has an optic sensor that can record approximately 500,000 measuring points within seconds (ca. 1.7s). Test persons' faces and plaster-cast models of them (n = 15) were measured comparatively and serially (n = 5) to test the validity and reliability of the method for maxillofacial procedures. These investigations show that this method is appropriate for recording three-dimensional soft-tissue profiles. First studies on patients before and after dysgnathia operations were undertaken. A prospective long-term study for collecting data on pre- and postoperative dysgnathia patients has been begun. Initially, it will record the changes in facial soft tissue on the basis of skeletal displacement. Later, predictions about the soft-tissue changes subsequent to dysgnathia surgery can be worked out on the basis of stored data matched with three-dimensional bone data.

[Three-dimensional registration of the facial surface using projected white light stripes (TRICOLITE - triangulation with coded light technique)]. / 3D-Erfassung der Gesichtsoberfläche durch Topometrie unter der Verwendung von projizierten Weißlichtstreifen.

Three-dimensional registration of the facial surface by methods which are currently in use is difficult because of the long measuring times required by point-based imaging systems. Artifacts caused by movement appear, e.g., blinking. Also the production of a facial plaster-cast model for measuring is not an adequate solution. In order to acquire data of the facial surface in a contact-free manner, a system is needed that has short measuring times, is able to record data of complex surfaces and at the same time does no harm to the open eyes. The method described here represents a new development of an industrial high tech CAD/CAM system. Unlike customary point-based imaging systems, the stripe projection method works using entire planes. Structured light is aimed at the surface to be measured, recorded by videocamera and calculated by triangulation; then the different views are combined by computer. The system has an optic sensor that can record approximately 500 000 measuring points within seconds (ca. 1.7s). Test persons' faces and plaster-cast models of them (n = 15) were measured compartively and serially (n = 5) to test the validity and reliability of the method for maxillofacial procedures. These investigations show that this method is appropriate for recording three-dimensional soft-tissue profiles. First studies on patients before and after dysgnathia operations were undertaken. A prospective long-term study for collecting data on pre- and postoperative dysgnathia patients has been begun. Initially, it will record the changes in facial soft tissue on the basis of skeletal displacement. Later, predictions about the soft-tissue changes subsequent to dysgnathia surgery can be worked out on the basis of stored data matched with three-dimensional bone data.

[Possibilities for correcting the neck profile in pterygium colli]. / Korrekturmöglichkeiten des Halsprofils beim Pterygium colli.

Pterygium colli is characterized by bilateral webbing of the neck extending from the mastoid to the acromion. There is a broad variation in aetiology, very often chromosomal and congenital diseases are included, and most of the known cases present in association with Turner's syndrome. In one case we applied a posterior approach for correction of the webbed neck defect, which involved wide anterolateral skin undermining and skin resections from the nape of the neck. The redundant tissue and underlying defect are corrected and the resultant scar is hidden in the scalp. In two other cases a Z-plasty procedure was used to reduce the hypertrophic tissue, leaving the hairline in the original course. On the long-term follow-up all cases presented with improved aesthetic results, but showed hypertrophic scars.

Analysis of lidocaine on the COBAS INTEGRA.

A new fluorescence polarization (FP) immunoassay was developed for the COBAS INTEGRA to quantitate lidocaine in serum and sodium heparin derived plasma. The COBAS INTEGRA, a random and continuous access clinical analyzer, performs the new lidocaine assay at a throughput of 300 tests per hour. Comparison studies with the Abbott TDx Lidocaine assay yielded a correlation coefficient of 0.99 and a regression value of INTEGRA = -0.01 + 0.95 TDx, n = 69. The assay was found to be linear throughout the concentration range of 0 to 10 micrograms/ml using CASCO STANDARDS's DOCUMENT TDM 1 Linearity Test Set and the COBAS-FP TDM Calibration Verification Test Set. The new lidocaine assay exhibited good precision as determined by the National Committee for Clinical Laboratory Standards (NCCLS) protocol EP5-T2 with total percent coefficient of variation (%CV) values of less than 4 percent across the assay range. Interference was less than 10 percent for abnormal levels of total protein (2.1 to 10 g/dl), lipid (up to 2200 mg/dl triglyceride), hemoglobin (up to 10 g/dl), and icteric samples (up to 17.5 mg/dl bilirubin). Finally, the standard curve was stable for greater than 25 weeks which was attributable to the on-board reagent cooling and a unique cassette closure system.

Can bacteremia be predicted in surgical intensive care unit patients?

OBJECTIVES: To determine which clinical features are associated with bacteremia in a SICU. To determine if infections are identified prior to bacteremia via culturing of other body fluids. To determine if antibiotic regimens are changed after the results of the blood culture were obtained. DESIGN: A retrospective, unit-based, case control study. SETTING: A 10 bed SICU in a 552-bed, tertiary care and Level I Trauma center. PATIENTS: All SICU patients with one or more positive blood cultures over a 2 year period (n = 24) were matched by diagnosis, procedure, and age to SICU patients with negative blood cultures (n = 48). MEASUREMENTS AND RESULTS: Bacteremic and control patients had similar APACHE II scores though death was more likely in bacteremic patients (p < 0.05) and they had higher hospital charges (p < 0.02). There was no difference in any of the clinical variables studied (minimum and maximum temperature, maximum white blood cell count, minimum mean arterial blood pressure) between the bacteremic and control groups on the days leading up to and the day of the positive blood culture. Coincident infections of lung, bladder, wound, and central venous catheters were identified in 42% of bacteremic patients. The identification of organisms found in the blood had a direct impact on the antibiotic regimen of 54% of the bacteremic patients. CONCLUSIONS: A better screen for obtaining blood cultures in this SICU was not identified. If antibiotics are begun empirically before the results of blood cultures are known, the results of other body fluid cultures can be used to guide therapy initially. However, the data obtained from positive blood cultures was often helpful in changing empirical therapy. Therefore, blood cultures remain important diagnostic tools.

Comparison of three immunoassays for the determination of N-acetylprocainamide. Determination of false elevations by a polyclonal antibody-based method.

The performance of the ROCHE FP NAPA reagent, a newly reformulated monoclonal antibody-based fluorescence polarization immunoassay (FPIA) for N-acetylprocainamide, was compared with two commercially available polyclonal antibody-based immunoassays, the Abbott TDx and Syva EMIT. Although excellent correlation was observed between the ROCHE FP NAPA reagent and the Syva EMIT reagent, a positive bias was observed in the correlation between the ROCHE FP NAPA reagent and the Abbott TDx reagent. The bias in the TDx method was investigated further by the concurrent high-performance liquid chromatography (HPLC) analysis of patient samples. Insignificant differences (p < 0.05) were observed between the HPLC and ROCHE FP values. The TDx system, however, yielded significantly higher (p < 0.0005) results than did HPLC.

Selective application of cardiopulmonary resuscitation improves survival rates.

This study is a retrospective review of all patients who died without cardiopulmonary resuscitation (CPR) or who sustained a sudden cardiopulmonary arrest in the hospital and received CPR during a 2-yr period at a large medical center. Based on a review of Current Procedural Terminology codes, patients were classified into one of the ten disease categories: multiple medical problems, acute disease, procedure-related, congenital disease, neoplasm, metastatic neoplasm, trauma, burn, acquired immunodeficiency syndrome, and dementia. A total of 1206 patient deaths without a CPR effort were identified. CPR was administered to another 550 patients who had a sudden cardiopulmonary arrest, of which 71% survived the resuscitative attempt initially, but only 25% survived CPR until discharge from the hospital. CPR was applied less frequently than the mean in the metastatic neoplasm (P < 0.0001), trauma (P = 0.013), and dementia (P = 0.0003) groups and more frequently in the acute disease (P < 0.0001) and procedure-related (P < 0.0001) groups. Survival to discharge from the hospital was more frequent than the mean in the congenital disease group (P = 0.0004) and less frequent in the neoplasm group (P = 0.0425). The other groups had survival rates comparable to the mean. Patients 70 yr of age and older were less likely to receive CPR than those younger than 70 (P < 0.0001). However, if they did receive CPR, they were just as likely to survive to discharge from the hospital as the younger patients (P = 0.3404).(ABSTRACT TRUNCATED AT 250 WORDS)

A controlled trial of scheduled replacement of central venous and pulmonary-artery catheters.

BACKGROUND: The incidence of infection increases with the prolonged use of central vascular catheters, but it is unclear whether changing catheters every three days, as some recommend, will reduce the rate of infection, It is also unclear whether it is safer to change a catheter over a guide wire or insert it at a new site. METHODS: We conducted a controlled trial in adult patients in intensive care units who required central venous or pulmonary-artery catheters for more than three days. Patients were assigned randomly to undergo one of four methods of catheter exchange: replacement every three days either by insertion at a new site (group 1) or by exchange over a guide wire (group 2), or replacement when clinically indicated either by insertion at a new site (group 3) or by exchange over a guide wire (group 4). RESULTS: Of the 160 patients, 5 percent had catheter-related bloodstream infections, 16 percent had catheters that became colonized, and 9 percent had major mechanical complications. The incidence rates (per 1000 days of catheter use) of bloodstream infection were 3 in group 1, 6 in group 2, 2 in group 3, and 3 in group 4; the incidence rates of mechanical complications were 14, 4, 8, and 3, respectively. Patients randomly assigned to guide-wire-assisted exchange were more likely to have bloodstream infection after the first three days of catheterization (6 percent vs. 0, P = 0.06). Insertions at new sites were associated with more mechanical complications (5 percent vs. 1 percent, P = 0.005). CONCLUSIONS: Routine replacement of central vascular catheters every three days does not prevent infection. Exchanging catheters with the use of a guide wire increases the risk of bloodstream infection, but replacement involving insertion of catheters at new sites increases the risk of mechanical complications.