Carotid sinus nerve blockade to reduce blood pressure instability following carotid endarterectomy: a systematic review and meta-analysis.

OBJECTIVES: Local anaesthetic infiltration into the carotid sinus during carotid endarterectomy (CEA) has been recommended to minimise blood pressure fluctuations but its use remains controversial. The aim of this meta-analysis was to determine whether intra-operative administration of local anaesthetic reduces the incidence of haemodynamic instability following CEA. MATERIALS AND METHODS: A search of the Medline, Pubmed and Embase databases and the Current Controlled Trials register identified four trials, which met the pre-defined inclusion criteria for data extraction. Pooled odds ratios with 95 per cent confidence intervals (c.i.) for the development of post-operative hypotension and hypertension were calculated using a random-effects model. RESULTS: Outcomes of 432 patients were studied. Local anaesthetic blockade of the carotid sinus was associated with a pooled odds ratio of 1.25 (95 per cent c.i. 0.496 to 3.15); p=0.216) and 1.28 (95 per cent c.i. 0.699 to 2.33; p=0.428) for the development of post-operative hypotension and hypertension respectively. Although none reach significance there was a trend towards increased risk of developing a complication in those patients who received local anaesthetic. CONCLUSIONS: There are insufficient data to determine the role of intra-operative local anaesthetic administration in reducing post-operative blood pressure lability following CEA. Conversely, the possibility of harm cannot be excluded on the basis of the currently available data.     

Update on chronic obstructive pulmonary disease.

Chronic obstructive pulmonary disease is one of the most significant chronic illnesses of adults. Comprehensive care of the affected patient requires the medical-surgical nurse to have knowledge of the disease process, collaborative management, and nursing care based on research and current practice guidelines.     

The development of food allergy after liver transplantation.

The acquisition of new food allergy after orthotopic liver transplantation is now a well described phenomenon, mainly reported in children. The etiology of this phenomenon is at present unclear, but has been ascribed by some to tacrolimus treatment. Here we report a case of liver transplant acquired food allergy (LTAFA) in a child who received a split liver graft. The case is remarkable for the absence of new food allergy in the adult recipient of the same graft. This suggests that host-specific factors play an important role in the development of food allergy after liver transplantation, and emphasizes the predisposition that children have toward this phenomenon. Possible mechanisms underlying the development of food allergy after liver transplantation are discussed. In conclusion, tacrolimus treatment alone cannot account for LTAFA. Host factors such as the maturity of immune regulatory mechanisms are likely to play a critical role in the development of new food allergy after a liver transplant.     

Morphological correlates of response dynamics and efferent stimulation in horizontal semicircular canal afferents of the toadfish, Opsanus tau.

1. We used the intraaxonal labeling technique to study correlations between the terminal dendritic morphology of horizontal semicircular canal primary afferents and their response dynamics to sinusoidal head rotation and combined electrical stimulation of central efferent vestibular neurons. Thirty-eight canal afferents were identified by their sensitivity and phase of response to rotation between 0.1 and 1.0 Hz (+/- 10 degrees/s) and were subsequently labeled with horseradish peroxidase or biocytin. The afferent's dendritic field and synaptic specializations in the neuroepithelium of the crista were examined under light microscopy. 2. Rate and regularity of background discharge of the afferent were not correlated with its axon diameter or relative location of its dendritic field in the crista. 3. Response sensitivity of the afferent to rotation was correlated both with the relative location of its dendritic field in the crista and with the number of terminal endings it possesses. Afferents having low sensitivities, slow dynamics, and few terminal endings supply the peripheral portions of the crista; afferents with higher sensitivities, faster dynamics, and greater number of terminal endings supply the more central portions. It is suggested that the differences in sensitivity among the afferents reflect principally the variations in both the cupular dynamics along the crista and the number of possible hair cell contact sites in the neuroepithelium. 4. Response phase of the afferent was correlated only with the extent of its dendritic processes along the transverse axis of the crista. Afferents having transversely oriented dendritic fields had less phase lags relative to acceleration than did those having a more longitudinally oriented dendritic field. 5. Efferent stimulation produced a change in both the afferent's discharge rate and its response sensitivity to rotation. Afferents discharge rate and its response sensitivity to rotation. Afferents having a centrally located dendritic field and acceleration afferents, defined by their response to rotation, were the most affected by efferent stimulation. These results suggest that efferent innervation is either directed toward, or most efficacious in, the central regions of the crista and that it may select specific hair cell-afferent complexes.     

Inhibitory effects of AH 21-132 in guinea-pig isolated ileum and taenia caeci.

1. AH 21-132 is being investigated as a potential chemotherapeutic agent for bronchial asthma. The present experiments were designed to determine whether AH 21-132 shares the activity of theophylline as an antagonist at adenosine A1 receptors and to assess its potency as a relaxant in intestinal smooth muscle. 2. In the transmurally-stimulated guinea-pig ileum, theophylline (1 mM), but not AH 21-132 (1 and 10 microM), antagonized twitch depression induced by adenosine. Higher concentrations (100 microM and 1 mM) of AH 21-132 themselves had a depressant effect. Neither theophylline (1 mM) nor AH 21-132 (1 and 10 microM) antagonized twitch depression induced by noradrenaline. 3. AH 21-132 (100 microM and 1 mM) depressed maximum contractions of ileum induced by both acetylcholine (ACh) and histamine. 4. In ileum treated with hyoscine (1 microM), AH 21-132 (greater than 10 microM) caused a concentration-dependent depression of the log concentration-effect curve for potassium chloride. 5. Simultaneous extracellular electrophysiological and mechanical recording from taenia caeci showed that AH 21-132 (100 microM-1 mM) inhibited spontaneous tension waves and their associated bursts of electrical spike activity. 6. Intracellular electrophysiological recording from taenia caeci showed that the mechano-inhibitory effect of 1 mM AH 21-132 was accompanied by abolition of spontaneous spike activity. Following spike abolition, the membrane potential assumed a value very close to that observed during periods of electrical quiescence prior to drug exposure. 7. AH 21-132 inhibited the activity of cyclic AMP-dependent and cyclic GMP-dependent phosphodiesterases derived from homogenates of ileal smooth muscle.(ABSTRACT TRUNCATED AT 250 WORDS)