Speed of injection

The BCs have been previously discussed by Gleaves et al. [1], Zou et al. [3], Creten et al. [9] and others. Initial condition (2) can he accepted because its statement of an initially clean surfece is an experimental statement. BCs (3, 4) are here further discussed with refenraice to the experimental apparatus. BC (3) states that the flux at the reactor Met is a delta fimction and is the approximation that pulse injection occurs over an inflnitely short time. This is discussed using experimental data on the speed of injection of the input pulse. BC (4) is the approximation that the gas concentration is zero outside the reactor tube. It implies tiM any gas eluting firom the reactor tube is immKiiately removed, that is, the approximation is that... 

For testing the V. marginalis of the rabbit ear is used. Only water soluble drug substances should be administered. Each animal receives a volume of 0.2-0.5 ml of the solution into the mechanically congested ear vein. The ear on the other side is treated with the vehicle only. An alternative method is to use extra animals for treatment with the vehicle only. The speed of injection (volume per time) should be similar to the human clinical situation. During the injection and after the animals have to be observed for clinical signs. In total the animals have to be checked for a period of 14 days. The site of injection has to be checked for signs of local reactions. 

It has been also observed that hypertonic and hypotonic salt solutions tend to irritate sensitive tissue and cause pain when applied to mucous membranes of the eye, ear, and nose, etc., whereas isotonic solution causes no tissue irritation when it comes in contact with the tissue. Obviously, the tonicity of formulations that come in to direct contact with blood, muscle, eye, nose, and delicate tissues is critical. Therefore, the issue of tonicity is important in small- and large-volume injectables, ophthalmic products, and products intended for tissue irrigation. The degree of tissue irritation or hemolysis or crenation observed depends on the degree of deviation from isotonicity, the volume injected, the speed of injection, the concentration of the solutes in the injection, and the nature of the membrane. The parenteral and ophthalmic formulations are therefore adjusted to isotonicity if possible. 

Drugs injected directly into the cerebrospinal fluid have a tendency to produce unpredictable effects, their spread being influenced not only by the volume administered, but also by the concentration of the drug, its specific gravity in relation to that of cerebrospinal fluid, the positioning of the patient (head-up or head-down), and on the speed of injection of bolus doses. Truncal muscle spasms can also increase the spread of drug within the cerebrospinal fluid. All these parameters need to be taken into consideration. Standardization is required as a first step. Rapid bolus injection in particular can produce unexpectedly severe adverse effects. 

The canse was thonght to be snbdnral injection, althongh other mechanisms conld not be exclnded for example the catheter conld have been partly intrathecal and the nlti-mate distribntion of the dose conld have been related to the speed of injection or catheter migration before the final dose was given. 

Presentation Transient radicular irritation causes transient pain in the back, buttocks, and lower extremities, without formal neurological signs or symptoms. It can follow single-dose intrathecal anesthesia. Lidocaine has been reported as the predominant culprit. However, transient radicular irritation has also been reported with bupivacaine, mepivacaine, tetracaine, and prilocaine. Osmolarity, the addition of dextrose, and speed of injection do not contribute, and even reducing the concentration of hdocaine does not alter the incidence (220,221). 

Gillies GW, Lees NW. The effects of speed of injection on induction with propofol. A comparison with etomidate. Anaesthesia 1989 44(5) 386-8. 

Suppressing Useful only for dryers with volume < 100 Not useful Suitabihty depends upon airflow rate and speed of injection Use limited to small-length dryers... 

The pressure exerted on the rubber in the cavity is related to the available pressure from the moulding machine, the speed of injection and the size of the runner through which it must flow to reach the mould cavity. The smaller the cross-sectional area of the runner, the higher is the pressure gradient between the point of injection and the cavity. If the length of the runners is the same to each cavity, there will be an equal rate of fill to all the cavities. If the path lengths are unequal, some cavities will fill before the others. Once a cavity has filled, it, and the related runner system, will rapidly achieve the full available... 

The reported incidence of pain during injection of propofol is 80%. The mechanism is not known, but direct irritation via nociceptors and activation of the kallik-rein-kinin cascade caused by kininogen release from the vascular wall have been proposed. Various strategies have been used in attempts to prevent propofol injection pain, including concomitant administration of lidocaine, ketamine, sodium thiopental, and fentanyl alteration of the speed of injection and adjusting the temperature of the injection solution. The most effective method to date has been the addition of lidocaine, which reduces the incidence to 40%. Four studies addressing this problem have been reported. 

Suitability depends upon airflow rate and speed of injection... 

Samples were injected onto the head of the column through a silicone rubber diaphragm by means of a 1 yl Hamilton microsyringe with standard needle. Frequent replacement of the diaphragm rubber was found to be necessary due to the high temperature used for vaporisation of the organotins, and the high pressure differential across the column itself. The speed of injection was not found to... 

The resulting colouration is controlled by the mixing dynamics of the materials in question and the shear they are subject to, for example, by the size and position of the sprue. Injection can be simultaneous or set on an alternating cycle to give a pulse type effect. The size of the injection steps and the speed of injection will also alter the colouration of the resultant moulding. Applications tend to be for mainly cosmetic applications such as covers and boxes and applications such as buttons where the colouration can be used to decorative effect. An example of a moulding is shown in Figure 10.16. 

Aronski et al. (45 ) studied systolic time intervals and peripheral blood flow in 12 patients after induction of anaesthesia with 0.05 ml/kg body weight Althesin and concluded that the drug has a definite cardio-depressive action. In another series of 220 patients (46 ) tachycardia and hypotension were seen in 35 and 25% of cases respectively. The respiratory depressant effect of the drug was related to the speed of injection. Muscle tremors were absent when Althesin was given by intravenous infusion. Even convulsions after Althesin have been described, immediately after the injection (4 C) or, in the case of less rapid injection, after some delay (48C). The slow injection of Althesin can indeed reduce the incidence of aU its side effects, as was shown in a comparison between 2 groups of 30 patients in which differing rates of administration were employed (49C). 

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