[Effect of electroacupuncture combined with cervical plexus block on stress responses in patients undergoing thyroid surgery].

OBJECTIVE: To observe the effect of electroacupuncture (EA) combined with cervical plexus block (CPB) on the stress response of patients undergoing thyroid surgery. METHODS: Forty thyroidectomy patients were randomly divided into sham EA plus CPB group (sham group) and EA+CPB group (20 cases in each group). For patients of the sham group, deep cervical plexus block (25% ropivacaine hydrochloride + 1% lidocaine hydrochloride) was performed first, followed by inserting acupuncture needles into bilateral Hegu (LI 4) and Neiguan (PC 6) separately without needle manipulation and then connecting the output wires of the EA therapeutic instrument to the handles of the acupuncture needles but without electric current output. For patients of the EA+CPB group, deep cervical plexus block was performed first followed by EA stimulation [10 Hz, (6 +/- 2) mA] of the bilateral LI 4 and PC 6 for 20 min. Systolic blood pressure (SBP), heart rate (HR) and breathing frequency were detected using a multipurpose monitor. Plasma adrenocorticotropic hormone (ACTH) and cortisol (Cor) contents were determined using chemiluminescence method, plasma epinephrine (E) level was detected by enzyme-linked immunosorbent assay, glucose (Glu) assayed by oxidase method, and plasma C-reactive protein (CRP) level detected using immumofluorescence technique. RESULTS: (1) During surgery, the patients' SBP and HR of both sham and EA groups were increased significantly compared with their basic values (P < 0.05), but the levels of the increased SBP and HR of the EA group were obviously lower than those of the sham group (P < 0.05). (2) The levels of plasma ACTH during surgery and at the immediate time after surgery, Cor level at the immediate time after surgery, plasma E and Glu contents during surgery, at the immediate time and on day 1 after surgery, and plasma CRP at the immediate time, and on day 1 and 3 after surgery in the sham group were upregulated considerably (P < 0.05), while the levels of plasma ACTH, Cor, E, Glu and CRP in the above-mentioned time-points of the EA group were all remarkably lower than those of the sham group (P < 0.05). CONCLUSION: EA combined with cervical plexus block significantly reduces peri-operative cardiovascular stress responses and inhibits abnormal increases of plasma stress hormones and inflammatory reaction in patients undergoing thyroid surgery.

Spread of injectate with superficial cervical plexus block in humans: an anatomical study.

BACKGROUND: This study was undertaken to investigate why the superficial cervical plexus block for carotid endarterectomy is so effective. Initial consideration would suggest that a superficial injection would be unlikely to block all terminal fibres of relevant nerves. One possibility is that the local anaesthetic crosses the deep cervical fascia and blocks the cervical nerves at their roots. METHODS: Superficial cervical plexus blocks (injections just below the investing fascia) were performed using methylene blue (30 ml) in four cadavers. In one additional control cadaver, a deep cervical plexus injection was performed. In a second control cadaver, a subcutaneous injection (superficial to investing fascia) was performed at the posterior border of the sternomastoid muscle. RESULTS: Anatomical dissection showed that with superficial block there was spread of the dye to structures beneath the deep cervical fascia. In the first control, dye remained in the deep cervical space. In the second control, dye remained subcutaneous. CONCLUSIONS: The superficial cervical space communicates with the deep cervical space and this may explain the efficacy of the superficial block. The method of communication remains unknown. Our findings also indicate that the suitable site of injection for the superficial cervical plexus block is below the investing fascia of the neck, and not just subcutaneous.

GABA-, glycine-, and glutamate-immunoreactive bouton profiles in apposition to neurons of the central cervical nucleus in the rat.

The neurons of the central cervical nucleus (CCN) convey information about the position and movements of the head, and receive excitatory input from dorsal neck muscles and the labyrinth. Both of these afferent sources form glutamatergic synaptic contacts with CCN neurons. However, these sensory afferent sources can also inhibit CCN neurons. To further elucidate the synaptic organization, we made an electron microscopic investigation, identifying and evaluating the relative frequency of bouton profiles containing the inhibitory transmitters GABA and glycine in apposition to identified CCN neurons. In addition, labeling for glutamate was performed. The identification of the CCN neurons was made possible by injections of retrograde tracer substances into the cerebellum. These substances were made visible by preembedding immunocytochemistry or postembedding immunogold staining. Such staining was also used to detect the three amino acids that were found in boutons apposed to the identified neurons (cf. Ornung et al., J. Comp. Neurol. 1996;365:413-426; Lindå et al., J. Comp. Neurol. 2000;425:10-23). Due to the relatively poor transport of the tracer substances into dendrites of the CCN neurons, the analysis was restricted to the cell body and included bouton profiles in direct apposition to the soma membrane. Data from 10 CCN neurons revealed that about 50% of the apposing bouton profiles were immunoreactive for GABA, and about 34% for glycine. In four neurons, the degree of colocalization of GABA and glycine was determined to be close to 30%. Thus, the vast majority of glycine-labeled profiles also contained GABA, while a considerable fraction of the profiles were immunoreactive for only GABA. The values for glycine immunoreactive bouton profiles presented here may represent somewhat low estimates, depending on the method used. Data from four neurons showed that about 18% of the profiles were labeled for glutamate. The large fraction of purely GABA immunoreactive profiles, or at least a substantial group of them, is suggestive of their derivation from axons descending from the brainstem.

Differentiation by pyridoxal 5-phosphate, PPADS and IsoPPADS between responses mediated by UTP and those evoked by alpha, beta-methylene-ATP on rat sympathetic ganglia.

1. The effect of pyridoxal 5-phosphate, and the 2',4' and 2',5'-disulphonic acid isomers of 6-azophenylpyridoxal 5-phosphate (PPADS and IsoPPADS respectively) on depolarization of the rat superior cervical ganglion evoked by alpha, beta-methylene-adenosine 5'-triphosphate (alpha, beta-Me-ATP) and uridine 5'-triphosphate (UTP) were determined by a grease-gap recording technique. 2. Pyridoxal 5-phosphate (10-100 microM) and PPADS (10-100 microM) enhanced UTP- and depressed alpha, beta-Me-ATP-evoked depolarizations but did not significantly alter depolarizations evoked by potassium or hyperpolarizations evoked by adenosine. IsoPPADS (10 microM) depressed alpha, beta-Me-ATP-evoked depolarizations but did not alter depolarizations evoked by UTP. Depolarizations evoked by muscarine were depressed by IsoPPADS but not by pyridoxal 5-phosphate. 3. It is concluded that pyridoxal 5-phosphate, PPADS and IsoPPADS are antagonists at P2x-purinoceptors but not at the receptors that mediate UTP-evoked depolarization of the rat superior cervical ganglion. These observations substantiate the recent proposal that the rat superior cervical ganglia possess distinct receptors for purine and pyrimidine 5'-nucleotides, i.c. P2x-purinoceptors and pyrimidinoceptors respectively.

The effect of 6-aminonicotinamide blockade of the pentose phosphate pathway on catecholamines in the rat adrenal medulla, superior cervical ganglion, hypothalamus and synaptosome fractions.

The effect on tissue catecholamines of blockade of the pentose phosphate pathway with 6-aminonicotinamide (6-AN) was studied in the rat. 6-AN at 35-50 mg kg-1 persistently lowered the adrenaline content in the adrenal gland to less than 10% of control values and caused a 50% loss of noradrenaline, which recovered. When the amine turnover rate was increased by a preceding period of drum stress, 6-AN also consistently depressed noradrenaline in the gland. 6-AN was without significant effect on the noradrenaline concentration in heart tissue, hypothalamus and superior cervical ganglion and did not affect the uptake or release of catecholamines in vitro. The possibility is discussed that 6-AN interferes with the biosynthesis of catecholamines, when it blocks the pentose phosphate pathway, by decreasing the supply of reducing equivalents in the form of NADPH which are necessary for the tetrahydropteridine cofactors of tyrosine hydroxylase.

Changes in (3H)leucine incorporation into pineal proteins following estradiol or testosterone administration: involvement of the sympathetic superior cervical ganglion.

Pineal denervation by superior cervical ganglionectomy (Gx) decreased high affinity binding of estradiol (E2) to the pineal cytosol of female rats and of testosterone to the cytosol of male rats by 40 and 26% and by 75 and 80%, 5 and 14 days after sugery; hormone binding remained unchanged up to 24 h after surgery. Binding to the nuclear fraction decreased sigificantly by 2 weeks after incorporation of (3H) leucine into pineal proteins in Gx. A single injection of E2 (mug) to testosterone propionate (TP) (500 mug) failed to increase the Gx rats when injected 1 or 5 days after surgery. Significant increases were observed in sham-operated controls or in rats subjected to bilateral decentralization of ganglia; however on the 5th day an impairment was observed in hormone ability to enhance [3H]leucine incorporation in decentralized rats. The administration of isoproterenol 19 and 3 h before sacrifice replenished pineal-binding sites for E2 and testosterone in Gx rats, but failed to restore the responsiveness of denervated pineals to hormone administration. Moreover, E2 or TP treatment blocked the increase in labeled amino acid incorporation into proteins brought about by isoproterenol per se. The administration of propranolol 2 and 7 h after hormone injection decreased the ability of E2 and TP to enhance [3H]leucine incorporation by 55 and 41%, respectively. Tyrosine hydroxylase activity of the superior cervical ganglia decreased by 36 and 41% 6 h after E2 or TP administration, and by 43 and 47% after 3 daily injections of the hormones, whereas pineal tyrosine hydroxylase remained unchanged. Hormone treatment for 3 days increased the in vitro uptake of norepinephrine by the ganglia but did not affect uptake in the pineal gland. These data indicate that the integrity of neurons of the superior cervical ganglia is an absolute requirement for E2 and testosterone to enhance [3H]leucine incorporation into pineal proteins in rats.