Effectiveness of Terbutaline Pump for the Prevention of Preterm Birth. A Systematic Review and Meta-Analysis

Subcutaneous terbutaline (SQ terbutaline) infusion by pump is used in pregnant women as a prolonged (beyond 48-72 h) maintenance tocolytic following acute treatment of preterm contractions. The effectiveness and safety of this maintenance tocolysis have not been clearly established. We aimed to systematically evaluate the effectiveness and safety of subcutaneous (SQ) terbutaline infusion by pump for maintenance tocolysis.MEDLINE, EMBASE, CINAHL, the Cochrane Library, the Centre for Reviews and Dissemination databases, post-marketing surveillance data and grey literature were searched up to April 2011 for relevant experimental and observational studies. Two randomized trials, one nonrandomized trial, and 11 observational studies met inclusion criteria. Non-comparative studies were considered only for pump-related harms. We excluded case-reports but sought FDA summaries of post-marketing surveillance data. Non-English records without an English abstract were excluded. Evidence of low strength from observational studies with risk of bias favored SQ terbutaline pump for the outcomes of delivery at <32 and <37 weeks, mean days of pregnancy prolongation, and neonatal death. Observational studies of medium to high risk of bias also demonstrated benefit for other surrogate outcomes, such as birthweight and neonatal intensive care unit (NICU) admission. Several cases of maternal deaths and maternal cardiovascular events have been reported in patients receiving terbutaline tocolysis.Although evidence suggests that pump therapy may be beneficial as maintenance tocolysis, our confidence in its validity and reproducibility is low, suggesting that its use should be limited to the research setting. Concerns regarding safety of therapy persist

First Paper: Tyre to Wet Road Friction at High Speeds

The general problem of loss of tyre grip on wet road surfaces is discussed. The initial section of the paper covers a description of the testing techniques employed for the investigations reported. These include both road and indoor rig techniques developed to study limiting tyre braking and cornering properties under a wide range of operating conditions. The level of friction between a tyre and a wet road is primarily related to the ability to remove a water film from the ground contact area. The contact area is considered to be separated into three effective zones. Initially the ‘bulk’ of the film is displaced leaving a thin residual film to be penetrated at, or absorbed from, the interface before substantially dry contact can be established. The size of this dry area, at the rear of the contact zone, has an overriding control on the level of available friction and is dependent upon the time occupied in displacing the water film in the frontal zones. An increase in the peripheral speed of the tyre reduces the time available for water displacement and effectively shortens the area of actual ground contact. In the limiting condition the vertical load on the tyre becomes entirely supported on the water film and the condition of aquaplaning exists. The requirements for this condition to occur are briefly discussed. Tread pattern and road surface design are shown to exert a considerable influence upon the rate of water displacement from the contact area and hence upon the relative sizes of the water-supported zones. The forces developed in the dry zone at the rear of the ground contact are dependent upon the frictional characteristics of the tread material. A section of the paper considers the wide scale effects of tread pattern, tread material and road surface characteristics and discusses the nature of the interactions between these three variables. Some results of recent studies related to different types of tread pattern, specific pattern design features and the effect of tyre casing construction are included. Future potential development of the tyre contribution is reviewed. </jats:p

Tire to Wet Road Friction at High Speeds

Abstract The general problem of loss of tire grip on wet road surfaces is discussed. The initial section of the paper covers a description of testing techniques employed for the investigations reported. These include both road and indoor rig techniques developed to study limiting tire braking and cornering properties under a wide range of operating conditions. The level of friction between a tire and a wet road is primarily related to the ability to remove a water film from the ground contact area. The contact area is considered to be separated into three effective zones. Initially the ‘bulk’ of the film is displaced leaving a thin residual film to be penetrated at, or absorbed from, the interface before substantially dry contact can be established. The size of this dry area, at the rear of the contact zone, has an overriding control on the level of available friction and depends on the time occupied in displacing the water film in the frontal zones. An increase in the peripheral speed of the tire reduces the time available for water displacement and effectively shortens the area of actual ground contact. In the limiting condition the vertical load on the tire becomes entirely supported on the water film and the condition of aquaplaning exists. The requirements for this condition to occur are briefly discussed. Tread pattern and road surface design are shown to exert a considerable influence on the rate of water displacement from the contact area and hence on the relative sizes of the water supported zones. The forces developed in the dry zone at the rear of the ground contact depend on the frictional characteristics of the tread material. A section of the paper considers the wide scale effects of tread pattern, tread material, and road surface characteristics and discusses the nature of the interactions between these three variables. Some results of recent studies related to different types of tread pattern, specific pattern design features, and the effect of tire casing construction are included and future potential development of the tire contribution is reviewed.</jats:p

Effect of pregnancy on the accuracy of light-reflection rheography.

Light-reflection rheography is a noninvasive method to detect venous obstruction by indirectly measuring venous emptying time. In nonpregnant women it has greater than 90% sensitivity when compared with venography but has not been tested during gestation. To determine if the nonthrombotic occlusion of venous outflow by the pregnant uterus might alter the performance of light-reflection rheography, we examined 17 normal patients with a vascular Accuscan (Hemodynamics, Inc., Boca Raton, Fla.) in the third trimester of pregnancy and 11 patients during the early second trimester. These results were compared with the defined normal (nonpregnant) rate of venous emptying (slope 0.54 +/- 0.06). The mean (+/- SD) for the entire sample was 0.58 +/- 0.23 mm/sec in the right leg and 0.52 +/- 0.19 mm/sec in the left leg measured in the standard sitting position (p = 0.21). The results did not vary with gestational age. A subset of patients in late pregnancy were used to compare the effect of various positions (supine, lateral decubitus, and sitting) on test performance. Positions other than sitting provided results that were inconsistent. It appears that the large pregnant uterus does not significantly obstruct venous outflow from the lower extremities in the standard sitting position; thus the results of light-reflection rheography are not affected. Comparison of light-reflection rheography versus venography in pregnant patients with suspected venous thrombosis is being investigated

A comparison study of pain associated with endocervical sampling techniques.

Endocervical curettage (ECC) is an important tool in the diagnosis and treatment of cervical neoplasia. Its use has been limited, however, because of the pain it can cause. We show that the use of a soft plastic curette cause statistically less pain without compromising the quantity or quality of the sample