Transmission of HIV Drug Resistance and the Predicted Effect on Current First-line Regimens in Europe

Transmitted human immunodeficiency virus drug resistance in Europe is stable at around 8%. The impact of baseline mutation patterns on susceptibility to antiretroviral drugs should be addressed using clinical guidelines. The impact on baseline susceptibility is largest for nonnucleoside reverse transcriptase inhibitors.

Background. Numerous studies have shown that baseline drug resistance patterns may influence the outcome of antiretroviral therapy. Therefore, guidelines recommend drug resistance testing to guide the choice of initial regimen. In addition to optimizing individual patient management, these baseline resistance data enable transmitted drug resistance (TDR) to be surveyed for public health purposes. The SPREAD program systematically collects data to gain insight into TDR occurring in Europe since 2001.

Methods. Demographic, clinical, and virological data from 4140 antiretroviral-naive human immunodeficiency virus (HIV)–infected individuals from 26 countries who were newly diagnosed between 2008 and 2010 were analyzed. Evidence of TDR was defined using the WHO list for surveillance of drug resistance mutations. Prevalence of TDR was assessed over time by comparing the results to SPREAD data from 2002 to 2007. Baseline susceptibility to antiretroviral drugs was predicted using the Stanford HIVdb program version 7.0.

Results. The overall prevalence of TDR did not change significantly over time and was 8.3% (95% confidence interval, 7.2%–9.5%) in 2008–2010. The most frequent indicators of TDR were nucleoside reverse transcriptase inhibitor (NRTI) mutations (4.5%), followed by nonnucleoside reverse transcriptase inhibitor (NNRTI) mutations (2.9%) and protease inhibitor mutations (2.0%). Baseline mutations were most predictive of reduced susceptibility to initial NNRTI-based regimens: 4.5% and 6.5% of patient isolates were predicted to have resistance to regimens containing efavirenz or rilpivirine, respectively, independent of current NRTI backbones.

Conclusions. Although TDR was highest for NRTIs, the impact of baseline drug resistance patterns on susceptibility was largest for NNRTIs. The prevalence of TDR assessed by epidemiological surveys does not clearly indicate to what degree susceptibility to different drug classes is affected.

Urapidil permeates the intact blood-brain barrier

OBJECTIVE

To determine the plasma and cerebrospinal fluid (CSF) levels of urapidil after i.v. administration and the effect on CSF serotonin and 5-hydroxyindoleacetic acid (5-HIAA) concentrations.

DESIGN

Open, single-dose study.

SETTING

Post-surgery following neurosurgical removal of the hypophysis (n = 5) or aneurysm clipping (n = 1).

PATIENTS

6 patients, aged 32-71 years, with intact blood-brain barrier (BBB); 1 patient was studied twice.

INTERVENTIONS

Single dose of 25 mg urapidil i.v. as prophylaxis of BP increase during extubation or as treatment of hypertensive episodes.

MEASUREMENTS AND RESULTS

Urapidil, serotonin and 5-HIAA were measured by HPLC in CSF during 8 h after urapidil administration. Urapidil was detected in CSF as soon as 5 min after injection in 3 patients. The concentration ratio of plasma/CSF after the distribution phase was about 5:1. No significant effect on serotonin and 5-HIAA in CSF was seen.

CONCLUSION

After administration of a therapeutic dose, urapidil permeates the BBB and may interact with central 5-HT1A-receptors.

Simultaneous measurement of cardiac output by thermodilution, thoracic electrical bioimpedance and Doppler ultrasound

To evaluate the accuracy of two non-invasive techniques for cardiac output (CO) measurement, we have measured CO simultaneously by thoracic electrical bioimpedance (TEB), pulsed Doppler ultrasound (DU) and standard thermodilution methods (TD) under different clinical conditions. Measurements were made in 10 patients: (I) during steady state anaesthesia with controlled IPPV ventilation (n = 131), spread over the entire ventilatory cycle; (II) during apnoea (n = 56); (III) during spontaneous breathing (n = 152) in the intensive care unit. Mean (SD) cardiac output values were: (I) COTD 3.5 (1.0) litre min-1, COTEB 3.4 (0.7) litre min-1, CODU 2.8 (0.7) litre min-1; (II) COTD 3.6 (0.6) litre min-1, COTEB 3.5 (0.4) litre min-1, CODU 2.9 (0.7) litre min-1; (III) COTD 7.7 (1.5) litre min-1, COTEB 7.6 (1.9) litre min-1, CODU 5.2 (1.4) litre min-1. The mean percentage deviation of TEB from TD ranged from -2.2% to 1.4% and that of DU from TD was from -16% to -32%. There were no statistically significant differences between TD and TEB, but TD and DU differed significantly during IPPV, apnoea and spontaneous ventilation (P < 0.0001).

[Psychosomatic, sedative and hemodynamic reactions following preoperative administration of midazolam in children]

Since children's intellectual perception is limited, the preoperative visit by an anesthesiologist alone can rarely help to free the small patients from fear and restlessness prior to elective surgery. In order to relieve anxiety which should be the primary goal of premedication in any patient - children need anxiolytic premedication agents. Drugs for premedication administered by intramuscular or rectal route in children often cause pain, fear and discomfort. The present study was performed in order to investigate oral given midazolam in the premedication of children with special regard to the practical suitability of this method. 100 children, 0.5 to 10 years of age (group A: 0.5-4 years, group B: 5-10 years) undergoing elective urological surgery received 0.4 mg/kg midazolam orally about 20 minutes prior to the arrival in the operation unit. After insertion of a venous cannula into a forearm vein anesthesia was induced with thiopental and maintained by inhalation with Isoflurane, nitrous oxide and oxygen (fi O2:0.3). Degree of sedation, state of mind and behaviour (for 100 children) as well as blood pressure and heart rate (separately for group A and B) were registered preoperatively at defined, comparable and representative circumstances. Side effects prior and during induction phase of anesthesia were documented. The personal data are representative for a normal population of children with typical urological diseases. Oral administered midazolam had only a mild or non sedative effect in 76-84% of the children 70-84% of the small patients showed an indifferent or euphoric state of mind and 67-88% behaved cooperatively or passively.(ABSTRACT TRUNCATED AT 250 WORDS)

Determination of cardiac output during positive end-expiratory pressure--noninvasive electrical bioimpedance compared with standard thermodilution

Many investigators have demonstrated the accuracy and reliability of thoracic electrical bioimpedance (TEB) in spontaneously breathing patients and under mechanical intermittent positive-pressure ventilation. Most of these studies showed a good correlation between TEB and invasive methods, such as thermodilution (TD) or the Fick method. But during PEEP, contrary results occur when comparing TEB and TD. In six patients undergoing neurosurgical interventions, TEB cardiac output measurements were compared during zero end-expiratory pressure (ZEEP) and during PEEP at 8 cm H2O with a low respiratory rate. The data revealed a good correlation during ZEEP (r = .93) and during PEEP (r = .91). There was no significant statistical difference when measuring cardiac output by TEB during ventilation with PEEP. During normal or decreased cardiac output, TEB overestimated cardiac output compared with TD, whereas TEB underestimated cardiac output compared with TD during increased cardiac output, especially during PEEP.

[A computer-assisted noninvasive monitoring system with graphic display of online determination of cardiovascular parameters]

During anesthesia the cardiovascular system is usually assessed on the basis of heart rate and arterial pressure, although the most important hemodynamic measurement is that of flow. A method for the non-invasive measurement of cardiac output is based on thoracic electrical bio-impedance. The NCCOM3-R7 is a non-invasive cardiac output monitor that makes use of thoracic electrical bioimpedance, which has been shown to provide results comparable with thermodilution in various hemodynamic states both in animals and humans. A new on-line hemodynamic monitoring system has been developed using the non-invasive NCCOM3-R7 (BoMed) cardiac output monitor, a portable microcomputer (NEC Multispeed) in connection with a software package CDDP-1 (BoMed), a Dinamap automatic arterial pressure monitor (Critikon) and an additional 14" display. Every 16 heart beats the cardiac output monitor transfers 11 cardiodynamic parameters in ASCII-format to the microcomputer, where the data are stored. Using the CDDP-1 program the current cardiodynamic status of the patient is displayed numerically and graphically on the monitor screen. Mean arterial pressure is determined by Dinamap and the data must be entered manually in the menu. The program then calculates systemic vascular resistance and left ventricular work index, the CVP being set to 3 torr and PAOP to 6 torr. In the graphic display the current hemodynamic status is shown and the underlying situation is analyzed in terms of systemic vascular resistance and volume-dependent contractility. The reliability of this on-line monitoring system is demonstrated in a high-risk patient.(ABSTRACT TRUNCATED AT 250 WORDS)

[Postoperative monitoring following short duration surgery of the ear, nose and throat. Experiences with midazolam as an anesthesia induction agent]

A combination of midazolam and alfentanil was used on 24 patients for induction of general anaesthesia. Anaesthesia was maintained with N2O/O2 and repeated injections of alfentanil. The mean operation time was 40.8 min. At the end of surgery the patients recovered 4.8 min after antagonisation of the alfentanil with naloxon, and the endotracheal tube could be removed. Thirty, 60 and 120 min after extubation the patients were asked to perform a Marschner's test, which measures the ability to concentrate on fast intellectual work. Up to 660 simple arithmetical additions could be checked within 7.5 min. The intellectual performance recovered quickly: after 30 min 79% of the pre-operative values were reached, after 60 min 85% and after 120 min 90%. Midazolam is suitable as an induction agent for shortlasting otorhinolaryngological surgery.

[Intra- and postoperative effect of various plasma substitutes on blood rheology and conjunctival oxygen partial pressure in microsurgical intervertebral disk operations]

In a prospective, randomized, controlled, parallel group study the effect of different infusion solutions (HES 200/0.5 10%, dextran 40 10% and electrolyte solution) during and after intervertebral disc microsurgery on blood fluidity and conjunctival partial oxygen pressure was measured. At the beginning of the operation all patients showed a reduction in conjunctival oxygen pressure - independent of the infusion solution. Both fluidity of blood and oxygen partial pressure changed according to the plasma substitute used. Thus after the administration of medium molecular weight hydroxyethyl starch an improvement in the fluidity of blood with a consecutive significant increase in the conjunctival oxygen pressure could be observed, whereas there was no increase after the administration of electrolyte solution and only a slight one (according to tendency) after infusion of dextran.