Apnea testing guided by continuous transcutaneous monitoring of partial pressure of carbon dioxide

OBJECTIVE: To continuously monitor PCO2 during two different protocols for apnea testing as part of the determination of brain death. DESIGN: Prospective comparative study using continuous transcutaneous PCO2 (tcPCO2) monitoring in 54 apnea tests with or without artificial CO2 augmentation. Another 53 apnea tests were not continuously monitored. SETTING: Intensive care wards in Northern Bavaria. PATIENTS: Ninety-six consecutive patients with suspected brain death. INTERVENTIONS: Apnea tests guided by transcutaneous monitoring during a PaCO2 of > or = 60 torr (> or = 8 kPa). MEASUREMENTS AND MAIN RESULTS: The mean of the difference between tcPCO2 and PaCO2 was -0.26 +/- 1.16 (SEM) torr (-0.035 +/- 0.15 kPa). Seventy percent of all transcutaneous measurements were within +/-10% of the PaCO2 values. The individual differences ranged from -25.8 to 16.9 torr (-3.44 to 2.25 kPa). CONCLUSIONS: While not as precise as could be desired in individual cases, the overall agreement between tcPCO2 and PaCO2 was good. Transcutaneous monitoring aided in effectively reducing the CO2 target overshoot with artificial CO2 augmentation, reduced the necessary number of blood gas checks compared with a former study, using predetermined time-locked evaluations, and prolonged only tests with artificial CO2 augmentation.     

Preliminary findings from a teleultrasound study in Alberta

This study is an examination of the interaction of humor and gender in moderating relationships among perceived stress, anxiety, and physical symptoms. Introductory psychology students (70 women, 61 men) completed self-report scales measuring perceived stress, humor, and symptomology. Multiple regression analyses revealed a moderating effect for humor between stress and anxiety, but only for men. When humor was low, a positive relationship was obtained between stress and anxiety; no relationship existed when humor was high. No gender differences were found in the significant moderating effect of humor between stress and physical symptoms. When humor was low, stress was related to physical symptoms; no relationship was found when humor was high. Overall, the findings supported humor as a moderator of stress; gender differences also existed for some outcomes.     

Proposed new bladder volume monitoring device based on impedance measurement

A new implantable bladder volume-monitoring device based on the impedance measurement of the detrusor muscle is described. The system is completely autonomous and forms a mixed-signal (analogue/digital) feedback loop with a neuro-stimulator to rectify bladder dysfunctions (incontinence and retention) through neuromuscular stimulation techniques. A programmable instrumentation amplifier and a signal processing block, to eliminate the artefacts caused by the patient's movements, have been designed and tested. The layout for the signal processing block has been realised in 0.8 micron BiCMOS technology.     

Therapeutic drug monitoring in pediatrics: a need for improvement

Therapeutic drug monitoring (TDM) is practiced for a number of frequently used drugs in infants and children. It is believed that monitoring drug levels will increase the probability of a therapeutic response and minimize the probability of adverse drug sequelae. Dose adjustments are based on measured drug levels interpreted relative to published therapeutic ranges which may or may not reflect the true relationship with either therapeutic or adverse effects. Potential errors derive from many sources, some amenable to solutions based on current knowledge, others awaiting improved understanding of the causes and consequences of unreliable therapeutic ranges.     

Reaching hidden populations of drug users by privileged access interviewers: methodological and practical issues

The methodological issues surrounding the use of a privileged access interviewer team to generate a network sample of drug users are examined. Traditionally network samples have tended to be used by qualitative researchers. Privileged access interviewing provides a mechanism for the application of a structured instrument to a network sampling model. In doing so some problematic issues in this area for structured methodology are overcome, reduced or standardized. The use of this method is appraised in terms of meeting the methodological requirements of the Drug Transitions study. The practical experiences of our group in using a privileged access interviewer team to interview more than 400 heroin users, many of whom were not in contact with treatment services, are discussed. This method is most appropriate for the quick collection of data, from diverse networks of drug users, by use of a structured instrument. Success is likely to be dependent on careful implementation. The ongoing monitoring of data quality is of particular importance, as is good management practice and the establishment of supportive and non exploitative relationships with the interviewer team.     

Ambulatory patient-activated arrhythmia monitoring: comparison of a new wrist-applied monitor with a conventional precordial device

Sensitivity of forced expiratory flow between 25% and 75% of the vital capacity (FEF25-75) in detecting airway obstruction was investigated in 14 children with mild-moderate asthma, allergic to house dust mites, while at high altitude (1756 m). Forced vital capacity (FVC), forced expiratory volume in 1 sec (FEV1), FEF25-75, and peak expiratory flow (PEF) were measured every 2 weeks for 12 weeks (total, 84 measurements). The presence or absence of wheezing at the chest auscultation was ascertained before each test. During the study period, a significant improvement of both mean (SD) FEF25-75 [61 (12)% vs. 68 (11)% of the predicted value, p = 0.005] and PEF [95 (16)% vs. 103 (13)%, p = 0.002] was observed. FEV1 changed only marginally [82 (7)% vs. 86 (6)%, p = 0.05]. Wheezing was present on 12/84 occasions. Wheezing was associated with abnormal FEF25-75 values on most occasions but not with abnormal FEV1 or PEF. FEF25-75 was decreased on 51% of days in which wheezing was absent. FEV1 and PEF were, respectively, normal in 69% (p < 0.0001) and 92% (p < 0.0001) of measurements in which FEF25-75 was abnormal. These results suggest that FEF25-75 may be considered a good indicator of airflow obstruction and a sensitive marker of respiratory improvement in asthmatic children during reduced antigen exposure.     

Organizing drug injectors against AIDS: Preliminary data on behavioral outcomes.

Describes a project based on organizing drug injectors to change their subculture in ways that promote lower risk behaviors. Initial and follow-up interviews were conducted with 368 Ss. Findings indicate a decline in high-risk behaviors such as renting or borrowing used syringes and an increase in risk-reducing behaviors such as using new syringes and condoms. Almost half the Ss entered drug abuse treatment during the follow-up period; 60% taught others to use bleach to decontaminate injecting equipment. Risk reduction was greater among Ss who attended group meetings. Thus, organizing drug injectors is a feasible intervention that should be adopted elsewhere. Drug injectors can take on responsibility in combating AIDS. All evaluations of interventions should measure Ss' efforts to spread the message to others. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Whole-cell and single-channel alpha1 beta1 gamma2S GABAA receptor currents elicited by a "multipuffer" drug application device

Pharmacological characterization of ion channels and receptors in cultured neurons or transfected cell lines requires microapplication of multiple drug solutions during electrophysiological recording. An ideal device could apply a large number of solutions to a limited area with rapid arrival and removal of drug solutions. We describe a novel "multipuffer" rapid application device, based on a modified T-tube with a nozzle made from a glass micropipette tip. Drug solutions are drawn via suction from open reservoirs mounted above the recording chamber through the device into a waste trap. Closure of a solenoid valve between the device and the waste trap causes flow of drug solution though the T-tube nozzle. Any number of drug solutions can be applied with rapid onset (50-100 ms) after a brief fixed delay (100-200 ms). Recombinant alpha1beta1gamma2S GABAA receptors (GABARs) transfected into L929 fibroblasts were recorded using whole-cell and single-channel configurations. Application of GABA resulted in chloride currents with an EC50 of 12.2 microM and a Hill slope of 1.27, suggesting more than one binding site for GABA. GABAR currents were enhanced by diazepam and pentobarbital and inhibited by bicuculline and picrotoxin. Single-channel recordings revealed a main conductance state of 26-28 pS. This device is particularly suitable for rapid, spatially controlled drug applications onto neurons or other cells recorded in the whole-cell configuration, but is also appropriate for isolated single-channel or multichannel membrane patch recordings.     

Reproducibility of drug efficacy predictions by Holter monitoring in the electrophysiologic study versus electrocardiographic monitoring (ESVEM) trial. ESVEM Investigators

The effect of a newly developed free radical scavenger (OPC-15161) on the progression of nephrotoxic serum (NTS) nephritis was evaluated. NTS nephritis rats were sacrificed immediately before and 1, 2, 3, 6, and 24 h and 13 and 19 days after intravenous injection of NTS. The tissue content of phosphatidylcholine hydroperoxide, the activity of superoxide, the activity of superoxide dismutase in the renal cortex, and the serum malondialdehyde levels were measured. The phosphatidylcholine hydroperoxide content in the renal cortex of OPC-15161-treated NTS nephritis rats was lower than that in the control rats 24 h after NTS injection. The activity of superoxide dismutase in OPC-15161-treated rats was sustained in contrast to the decrease in this activity in the control rats 6 h after injection of NTS. The effects of OPC-15161, dipyridamole, and prednisolone on NTS nephritis rats were investigated. OPC-15161 (20 mg/kg p.o.) showed a potent inhibitory effect on the urinary protein excretion, whereas dipyridamole (30 and 100 mg/kg p.o.) and prednisolone (2 mg/kg p.o.) had less suppressive effects. In view of these results, we conclude that OPC-15161 notably ameliorated the urinary protein excretion by way of the suppression of lipid peroxidation in the renal tissue of NTS nephritis rats.     

Compliance and adverse drug reactions: a prospective study with ethinylestradiol using continuous compliance monitoring

This study examined the relationship between adverse reactions and patient compliance with ethinylestradiol at 40 micrograms twice daily versus 20 micrograms four times daily. In a randomized study 61 female patients with primary infertility were prescribed the drug twice daily (n = 31) or four times daily (n = 30). Ethinylestradiol was administered for 7 days before the sperm cervical mucus penetration-test was performed for hormonal standardization of the cervical mucus quality. Drug compliance was measured by continuous monitoring using the Medication Event Monitoring System. Two parameters were evaluated: percentage of prescribed doses taken (administration compliance) and adherence to the prescribed dose schedule (regimen compliance, number of days with two or four dosing events recorded). Adverse drug reactions were assessed using a standardized questionnaire. Fourty-four women experienced side effects, of which 81% were rated by patients as being mild. Patient compliance was higher with the twice daily than with the four times daily regimen: 85% versus 65% prescribed doses taken (P < 0.05). There was no significant difference in compliance comparing patients with and without adverse reactions (82% versus 72%, respectively), but compliance was lower and more irregular with at least 3 versus one or two adverse reactions reported: 54% versus 84% in administration compliance and 31% versus 58% in regimen compliance (P < 0.05). Compliance was also lower in patients with nausea and vomiting than in those without these symptoms, 59% versus 91% and 34% versus 66% (P < 0.005), respectively, and lower with moderate or severe compared to mild side effects; 48% versus 85% and 25% versus 59% (P < 0.005).(ABSTRACT TRUNCATED AT 250 WORDS)     

Theoretical and practical aspects of tube sinking by a rotary die

This paper is concerned with a method of analyzing the process of tube sinking by a rotary die, modifying the method of finite elements. The components of the state of strain tensor have been determined for the conventional tube sinking process as well as a rotary die. It has been proved that the adoption of a rotary die does not essentially change the scheme of the state of strain, but that it does, however, reduce the drawing force. The results of theoretical analysis have been compared with those of experimental tests effected by means of a special device ensuring die rotation.     

In vivo results with a new device for ultrasonic monitoring of pig skin cryosurgery: the echographic cryoprobe

One of the main difficulties encountered in cryosurgery is the uncertainty in the extent and depth of the tissue effectively treated during the freezing process. The objective of this study was to evaluate in vivo ultrasonic control of skin cryosurgery using a new echographic cryoprobe. An echographic cryoprobe, developed specifically for dermatology applications, combines a high-frequency (20 MHz) miniature ultrasonic transducer and a N2O-driven closed cryoprobe. Knowledge of the ultrasound velocity of frozen skin is a prerequisite for monitoring the iceball formation kinetics. Therefore, in a first study, we estimated the ultrasound velocity of frozen skin specimens. In a second step, the operation of the echographic cryoprobe was assessed, under in vivo conditions similar to those used in human therapeutics, on normal skin of three female "Large-White" pigs under anesthesia. The mean value of ultrasound velocity of frozen skin obtained by pooling the data from all the skin specimens included in this study was 2865 +/- 170 m per s. The average rates of growth (10(-2) mm per s) of the iceballs were found to be 12.2 +/- 1.0 (pig 1), 9.0 +/- 1.0 (pig 2), and 8.4 +/- 0.9 (pig 3). The echographic cryoprobe had a built-in high-frequency ultrasonic transducer that served two functions. It enabled in vivo real-time monitoring of depth penetration of the iceball and it gave important feedback to the operator or to the console relating to the rate of growth of the iceball. Automatic (i.e., operator-independent) detection of the echo signal from the freezing front and calculation of the depth penetration of the iceball was possible.     

Total testing process applied to therapeutic drug monitoring: impact on patients' outcomes and economics

The Total Testing Process (TTP) refers to the sequence of 11 steps of laboratory testing, beginning with a clinical question prompted by the patient-clinician encounter and concluding with the impact of the test result on patient care. TTP when applied to therapeutic drug monitoring (TDM) emphasizes that TDM must be considered a process involving a series of steps and interrelated activities and not viewed simply as a numerical value for a serum drug concentration. TTP is also an ideal format for organizing and identifying the system-related and patient-centered variables used in outcomes assessment of TDM, as well as providing a template for collecting the cost data needed for economic analyses. Examples are provided for improving application of TDM by practitioners, clinical laboratories, and educators.