Local Anaesthetic effect of carticaine [Ultracaine] in comparison to lidocaine

The aim of this work was to study carticaine and its local anesthetic properties in comparison with lidocaine. The results revealed that in intravenous regional analgesia, the onset time and duration of analgesic action till full recovery were shorter with carticaine. There was no significant difference between the two groups in the quality of anesthesia and motor block. In spinal analgesia, both local anesthetics acted similarly, but the loss of tactile sensation and motor block began earlier with carticaine. In epidural analgesia, there was no difference between carticaine and lidocaine in the onset time and spread of analgesia or motor block. The duration of analgesia was longer with carticaine. In dental patients, the onset of analgesia with nerve block as well as infiltration anesthesia was quicker with carticaine as compared with lidocaine

Sevoflurane versus halothane for the incidence and type of arrhythmia during anaesthesia for adenotonsillectomy in children

This study was carried on 60 patients scheduled for adenotonsillectomy to compare the incidence and type of arrhythmia during sevoflurane or halothane anesthesia. All patients were premedicated with atropine 0.01-0.02 mg/kg im 30 minutes before induction of anesthesia, then received inhalation induction using nitrous oxide 50% in oxygen supplemented with either sevoflurane or halothane. Time to loss of eyelash reflex was more rapid with sevoflurane than halothane, although time to adequate anesthesia to allow the insertion of endotracheal tube was slower in sevoflurane group. The incidence of cardiac arrhythmia was higher during halothane [40%] than during sevoflurane anesthesia [20%] and the arrhythmia was more often ventricular in origin in the two groups

Some pharmacodynamic aspects of ropivacaine on the cardiovascular system

In a previous work, it was demonstrated that ropivacaine, an aminoamide local anaesthetic, possessed a negative inotropic activity on isolated rabbit heart. It also elicited vasopressor effect on arterial blood pressure of anaesthetized cats. Bradycardia occurred only with high doses of the drug. The present study was designed to clarify the mechanism by which ropivacaine affect cardiac contractility, blood pressure, heart rate and vascular reactivity. The bradycardia and the vasopressor effect of ropivacaine was proved in spinal cat preparations to be the result of a peripheral action of the drug. This hypertensive response was furtherly proved to be mediated via activation of alpha adrenergic receptors and blocking beta2 adrenoceptors.-The negative inotropic action of ropivacaine was found to be probably the result of a beta adrenergic blocking effect and a direct action of the drug. Furthermore, different doses of ropivacaine [1.5-12 micro g/ml] elicited well-pronounced potentiation of the height of norepinephrine-induced concentrations of spiral aortic strips isolated from normal rabbits. This enhancement could be attributed to its alpha adrenergic agonistic effect. Concerning the isolated rat hind limb, it was found in the present investigation that ropivacaine produced dose dependent minor reduction in vascular outflow, which may be due to the increased peripheral resistance produced by the drug. In this study, it was concluded that the vasopressor effect of ropivacaine seems to be mediated via alpha adrenoceptor agonistic and beta adrenergic blocking activities while the negative inotropic effect of the drug may be due to a direct action on the heart and a beta-adrenergic receptor blockade of the myocardial tissue

Study of some parameters of endothelial dysfunction and coagulopathies in schistosomal cor pulmonale patients

Shistosomal cor-pulmonale [SCP] is one of the most important causes of vascular cor-pulmonale in Egypt. The aim of the work was to study the role of endothelial coagulation interaction in the initiation and /or progression of SCP. The study was carried out on 26 male schistosomal patients. They were divided into 2 groups: Group I [GI]: 16 patients with SCP. Group II [GII]: 10 schistosomal non-corpulmonale patients of matched age. All patients were subjected to cardiac Echo-Doppler study and right heart catheterization for measurement of blood pressure in the pulmonary artery and right ventricle. Blood samples obtained from the pulmonary artery were utilized for measurement of: - Fibrinogen. - vWF activity.-Platelet aggregation index.- Fibrin monomers. vWF activity was significantly higher in GI[173.4 +/- 58%] compared with GII [109.8 +/- 17.3%] and there was a statistically significant positive correlation between vWF activity and systolic pulmonary artery pressure [SPAP] [r = 0.654],P = 0.006] and a statistically significant negative correlation between vWF activity and platelet aggregation index [r = -0.6557,P 0.006]. Fibrinogen level was found to be significantly lower in GI [149 +/- 25.2 mg%] compared with GII [269 +/- 36.3 mg%]. Several signs indicating intra-vascular coagulopathy have been observed in GI since platelet aggregation index in that group [0.69 +/- 0.09] was markedly lower than its value in GII [0.95 +/- 0.02], signifying the increased propensity for thrombosis inside the pulmonary artery in GI compared with GII. Moreover, fibrin monomers have been detected in the pulmonary artery in 87% of cases of GI while they were not detected in any case in GII. We conclude that endothelial dysfunction and local coagulopathy in lung vasculature of SCP patients are important to proggression, if not initiation, of pulmonary hypertension

Comparison between mivacurium and atracurium in neuromuscular block and cardiovascular effects in patients receiving nitrous oxide - oxygen - halothane or nitrous oxide - oxygen - narcotic anaesthesia

This study was done on 60 patients of both sexes ASA I and II undergoing routine surgical operation in Al-Zahraa Hospital from March 1996 to March 1997, the study was undertaken to determine the neuromuscular block and cardiovascular effects of mivacurium in comparison with atracurium in 60 patients in two groups, each group 30 patients was subdivided into [a, b, c]. In group I, Halothane group [HAL] it was found that the mean onset for the low dose of mivacurium and that of atracurium were similar while the onset of high dose was much shorter, there was a highly significant difference between atracurium and both doses of mivacurium for the train of four [TOF] and the recovery index [RI]. In group II, [BAL] the balanced group there was no difference in the onset between both doses of mivacurium and that of atracurium, in comparison there was a highly significant difference between atracurium and the high dose of mivacurium in RI and TOF. Comparing group I and II halothane was found to potentiate the effect of mivacurium at neuromuscular junction with a high significant difference both at the low dose and at the high dose when compared with the balanced group. It was concluded that the spontaneous recovery from mivacurium induced neuromuscular block is very rapid and there is less need for neostigmine- atropine induced antagonism. The haemodynamic effects of mivacurium was also assessed, that the cardiovascular safety of mivacurium is proved by absence of clinically significant alteration from base line mean arterial pressure [MAP] and heart rate [HR] during bolus administration at doses up to 0.15 mg/kg. The cardiovascular effects of mivacurium may become evident after injection of larger doses. The present study revealed that mivacurium may be a useful nondepolarizing alternative to suxamethonium in elective procedures and in situation where rapid onset of action is not necessary. Due to its short duration of action and rapid recovery it is used as an adjunct to general anaesthesia, to facilitate tracheal intubation and provide skeletal muscle relaxation during surgery or mechanical ventilation for short procedures, and in situation where antagonism of residual neuromuscular block is considered undesirable

Role of platelet aggregation in the pathogenesis of schistosomal cor pulmonale

Various mechanisms may contribute to the production of pulmonary hypertension which is the essential underlying hemodynamic factor in the production of schistosomal cor pulmonale. However, the pathophysiology of pulmonary hypertension is still, in many cases, unclear. This work was planned to study the role of platelets in the development of pulmonary hypertension in schistosomal patients. It was conducted on 15 hepatosplenic patients [10 with schistosomal cor pulmonale [group I] and 5 without [group II]]. Pulmonary arterial samples taken from group I and II showed increased platelet aggregates, decreased platelet count and fibrinogen levels, prolonged PPT and euglobulin clot lysis time in group I when compared with group II. Detection of circulating platelet aggregates in the first group was used as a simple screening test for the presence of intravascular coagulation in the pulmonary circulation of this group. Platelets release vasoconstrictor substances [5 hydroxytryptamine 5HT and thromboxane A2] during aggregation or activation and these substances may be a contributing vasospastic factor in pulmonary hypertension in the schistosomal patients