Effect of nerve block on response of forearm blood flow to local temperature

To determine the role of neurotransmitter in the response of forearm blood flow (ABF) to local (forearm) skin temperature (Tsk) we measured ABF of six subjects at Tsk from 25 to 40 degrees C before (control) and after brachial plexus block (BPB). Control experiments were conducted in an ambient temperature of 27–29 degrees C, adjusted to minimize the subject's overall thermal sensation. Tsk was regulated by blowing a controlled-temperature airstream through a plastic bag enclosing the arm. We first lowered Tsk to 25 degrees C and after 20 min began to measure ABF with Whitney strain gauges. We then raised Tsk by 2.5 degrees C steps to 40 degrees C and measured ABF every 30 s for at least 10 min at each level of Tsk. Mean ABF rose from 1.1 ml X 100 ml-1 X min-1 at Tsk of 25 degrees C to 2.1 ml X 100 ml-1 X min-1 at 32.5 degrees C to 13.7 ml X 100 ml-1 X min-1 at 40 degrees C in control experiments and from 2.8 to 4.4 to 14.8 ml X 100 ml-1 X min-1 after BPB. The effect of Tsk on ABF was highly significant (P less than 0.0001) but the effect of BPB was not (P approximately equal to 0.2). At thermoneutrality, the effect of Tsk on ABF is largely independent of neural activity, since this effect is unaffected by nerve block.

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Respiratory effect of interscalene brachial plexus block vs combined infraclavicular plexus block with suprascapular nerve block for arthroscopic shoulder surgery

Journal of Clinical Anesthesia ◽

10.1016/j.jclinane.2017.11.029 ◽

2018 ◽

Vol 44 ◽

pp. 117-118 ◽

Cited By ~ 1

Author(s):

Lara Gianesello ◽

Vittorio Pavoni ◽

Iacopo Burzio ◽

Alberto Boccaccini

Keyword(s):

Brachial Plexus ◽

Nerve Block ◽

Brachial Plexus Block ◽

Suprascapular Nerve ◽

Shoulder Surgery ◽

Interscalene Brachial Plexus Block ◽

Respiratory Effect ◽

Suprascapular Nerve Block ◽

Arthroscopic Shoulder Surgery ◽

Plexus Block

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Comparison between Intravenous and Perineural Dexamethasone in Prolonging the Analgesic Effect of Supraclavicular Plexus Nerve Block

QJM ◽

10.1093/qjmed/hcaa039.017 ◽

2020 ◽

Vol 113 (Supplement_1) ◽

Author(s):

H M M Elzahaby ◽

K Y Kamal ◽

D F Emam ◽

M Y Saad

Keyword(s):

Chronic Pain ◽

Nerve Block ◽

Motor Block ◽

Brachial Plexus Block ◽

Ultrasound Guided ◽

Post Surgery ◽

Dexamethasone Group ◽

Supraclavicular Brachial Plexus Block ◽

Hospital Stays ◽

Plexus Block

Abstract Background poor controlled acute pain post-surgery is accompanied with several unwanted postoperative consequences, including patient agony, distress, myocardial ischemia, increased hospital stays and an increased possibility of post-operative chronic pain. Aim of the Work to study the effect of dexamethasone as a supplementary to bupivacaine in supraclavicular brachial plexus block. The comparison included the onset and the duration of the motor and sensory blocks, the duration of analgesia of the block and their effect on the postoperative analgesic needs. The effect of the drugs on hemodynamics and monitoring for the occurrence of any complication. Patients and Methods in our study, 50 patients were randomly divided into 2 equal groups. Perineural group received bupivacaine (0.5%) assosciated with 8 mg dexamethasone and Systemic group in which 8 mg of dexamethasone was injected systemically. All patients received equal volumes of 20 milliliters. Results our study revealed that adding 8 milligram of dexamethasone to bupivacaine in ultrasound-guided supraclavicular nerve block decreased the onset times of motor and sensory blocks and significantly increased their durations. In addition, dexamethasone prolonged the time of analgesia of the plexus block markedly, as shown by the time of request of first analgesia. Moreover, in perineural dexamethasone group, postoperative analgesic needs were much lesser than that of bupivacaine groups. Addition of dexamethasone perineural also did not affect the hemodynamics to a significant level. This makes perineural dexamethasone with bupivacaine more superior than the use of bupivacaine with addition of intravenous dexamethasone. Conclusion addition of Dexamethasone to bupivacaine in supraclavicular nerve block shortened the onset times of both sensory and motor blocks than injecting dexamethasone intravenously. Addition of Dexamethasone to bupivacaine significantly prolongs both sensory and motor block durations than injecting dexamethasone intravenously.

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Interactions between local and reflex influences on human forearm skin blood flow

Journal of Applied Physiology ◽

10.1152/jappl.1976.41.6.826 ◽

1976 ◽

Vol 41 (6) ◽

pp. 826-831 ◽

Cited By ~ 77

Author(s):

J. M. Johnson ◽

G. L. Brengelmann ◽

L. B. Rowell

Keyword(s):

Blood Flow ◽

Skin Blood Flow ◽

Forearm Blood Flow ◽

Lower Body Negative Pressure ◽

Muscle Blood Flow ◽

Whole Body ◽

Vasoconstrictor Response ◽

Human Forearm ◽

Forearm Skin ◽

Forearm Muscle

A three-part experiment was designed to examine interactions between local and reflex influences on forearm skin blood flow (SkBF). In part I locally increasing arm skin temperature (Tsk) to 42.5 degrees C was not associated with increases in underlying forearm muscle blood flow, esophageal temperature (Tes), or forearm blood flow in the contralateral cool arm. In part II whole-body Tsk was held at 38 or 40 degrees C and the surface temperature of one arm held at 38 or 42 degrees C for prolonged periods. SkBF in the heated arm rose rapidly with the elevation in body Tsk and arm Tsk continued to rise as Tes rose. SkBF in the arm kept at 32 degrees C paralleled rising Tes. In six studies, SkBF in the cool arm ultimately converged with SkBF in the heated arm. In eight other studies, heated arm SkBF maintained an offset above cool arm SkBF throughout the period of whole-body heating. In part III, local arm Tsk of 42.5 degrees C did not abolish skin vasoconstrictor response to lower body negative pressure. We conclude that local and reflex influences to skin interact so as to modify the degree but not the pattern of skin vasomotor response.

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Role of Nitric Oxide towards Vasodilator Effects of Substance P and ATP in Human Forearm Vessels

Clinical Science ◽

10.1042/cs0920123 ◽

1997 ◽

Vol 92 (2) ◽

pp. 123-131 ◽

Cited By ~ 18

Author(s):

Masanari Shiramoto ◽

Tsutomu Imaizumi ◽

Yoshitaka Hirooka ◽

Toyonari Endo ◽

Takashi Namba ◽

...

Keyword(s):

Nitric Oxide ◽

Blood Flow ◽

Substance P ◽

Sodium Nitroprusside ◽

Forearm Blood Flow ◽

Dependent Manner ◽

Human Forearm ◽

Before And After ◽

Dose Dependent

1. It has been shown in animals that substance P as well as acetylcholine releases endothelium-derived nitric oxide and evokes vasodilatation and that ATP-induced vasodilatation is partially mediated by nitric oxide. The aim of this study was to examine whether vasodilator effects of substance P and ATP are mediated by nitric oxide in humans. 2. In healthy volunteers (n = 35), we measured forearm blood flow by a strain-gauge plethysmograph while infusing graded doses of acetylcholine, substance P, ATP or sodium nitroprusside into the brachial artery before and after infusion of NG-monomethyl-l-arginine (4 or 8 μmol/min for 5 min). In addition, we measured forearm blood flow while infusing substance P before and during infusion of l-arginine (10 mg/min, simultaneously), or before and 1 h after oral administration of indomethacin (75 mg). 3. Acetylcholine, substance P, ATP or sodium nitroprusside increased forearm blood flow in a dose-dependent manner. NG-Monomethyl-l-arginine decreased basal forearm blood flow and inhibited acetylcholine-induced vasodilatation but did not affect substance P-, ATP-, or sodium nitroprusside-induced vasodilatation. Neither supplementation of l-arginine nor pretreatment with indomethacin affected substance P-induced vasodilatation. 4. Our results suggest that, in the human forearm vessels, substance P-induced vasodilatation may not be mediated by either nitric oxide or prostaglandins and that ATP-induced vasodilatation may also not be mediated by nitric oxide.

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The Incidence and Aetiology of Phrenic Nerve Blockade Associated with Supraclavicular Brachial Plexus Block

Anaesthesia and Intensive Care ◽

10.1177/0310057x7900700406 ◽

1979 ◽

Vol 7 (4) ◽

pp. 346-349 ◽

Cited By ~ 75

Author(s):

G. E. Knoblanche

Keyword(s):

Brachial Plexus ◽

Nerve Block ◽

Phrenic Nerve ◽

Brachial Plexus Block ◽

X Ray ◽

Supraclavicular Approach ◽

True Incidence ◽

Supraclavicular Brachial Plexus Block ◽

Plexus Block ◽

Phrenic Nerve Block

A trial to ascertain the true incidence of inadvertent phrenic nerve block with brachial plexus block via the supraclavicular approach was carried out. Phrenic nerve block was monitored by x-ray screening of the diaphragm. There was an incidence of phrenic nerve block of 67% (10 cases of diaphragmatic paralysis in 15 brachial blocks). The possible causes of phrenic nerve block with brachial block are discussed. It is concluded that the phrenic nerve is blocked peripherally in front of the scalenus anterior.

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Haemodynamic Effects of Eating: The Role of Meal Composition

Clinical Science ◽

10.1042/cs0900269 ◽

1996 ◽

Vol 90 (4) ◽

pp. 269-276 ◽

Cited By ~ 45

Author(s):

U. Høst ◽

H. Kelbaek ◽

H. Rasmusen ◽

M. Court-Payen ◽

N. Juel Christensen ◽

...

Keyword(s):

Blood Flow ◽

Cardiac Output ◽

Portal Vein ◽

Forearm Blood Flow ◽

Plasma Catecholamines ◽

Left Ventricular ◽

Gastric Distension ◽

Left Ventricular Volumes ◽

Portal Vein Flow

1. The purpose of this study was to investigate the effect of fractional meal stimulation on postprandial haemodynamic changes, the possible correlation between these changes and the potential mediating role of circulating catecholamines and insulin. 2. Healthy young subjects were studied before and after ingestion of isocaloric, isovolumetric high-protein, carbohydrate or fat meals (80–85% of total energy), 60 kJ per kg of body weight. Multigated radionuclide cardiography with autologous 99mTc-labelled erythrocytes was performed for assessment of cardiac output, venous occlusion plethysmography to obtain forearm blood flow and Doppler-ultrasonography for portal vein flow. Plasma levels of catecholamines and insulin were determined by radioimmunoassay. 3. Cardiac output increased considerably after each meal, including the control meal (water) with only minor differences in extent and timing. Left ventricular volumes increased after food intake, most pronounced after carbohydrate and protein. Forearm blood flow increased only after carbohydrate and protein. Portal vein flow increased after all meals, especially after fat, but also after the control meal. There was a significant correlation between the increment in cardiac output and changes in forearm and portal vein flow, but no correlation between either haemodynamic response and plasma catecholamines or insulin. 4. Postprandial cardiovascular changes are not substantially different after various isocaloric and isovolumic meal compositions. Gastric distension seems to play a role in the increase in cardiac output, accomplished by ventricular dilatation. These changes seem to some extent to be linked to changes in muscle and splanchnic flow.

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The effect of local heating on blood flow in the finger and the forearm skin

Canadian Journal of Physiology and Pharmacology ◽

10.1139/y87-210 ◽

1987 ◽

Vol 65 (6) ◽

pp. 1329-1332 ◽

Cited By ~ 18

Author(s):

Tetsuo Nagasaka ◽

Kozo Hirata ◽

Tadahiro Nunomura ◽

Michel Cabanac

Keyword(s):

Blood Flow ◽

Relative Humidity ◽

Local Heating ◽

Venous Occlusion ◽

Water Bath ◽

Strain Gauges ◽

Forearm Skin ◽

Thermal Sweating ◽

Hot Environments ◽

Male Subjects

Blood flow of the finger and the forearm were measured in five male subjects by venous occlusion plethysmography using mercury-in-Silastic strain gauges in either a cool–dry (COOL: 25 °C, 40% relative humidity), a hot–dry (WARM: 35 °C, 40% relative humidity), or a hot–wet (HOT: 35 °C, 80% relative humidity) environment. One hand or forearm was immersed in a water bath, the temperature (Tw) of which was raised every 10 min by steps of 2 °C until it reached 41° or 43 °C. While the other hand or forearm was kept immersed in a water bath (Tw, 35 °C), blood flow in the heated side (BFw) was compared with the corresponding blood flow in the control side (BFc). Under WARM or HOT conditions, linger BFw was significantly lower than finger BFc at a Tw of 39–41 °C in the majority of subjects. When Tw was raised to 43 °C, however, finger BFw became higher than BFc in nearly half of the subjects. In the COOL state, finger BFw did not decrease but increased steadily when Tw increased from 37° to 43 °C. In the forearm, BFw increased steadily with increasing Tw even in WARM–HOT environments. No such heat-induced vasoconstriction was observed in the forearm. From these results we conclude that in hyperthermic subjects, the rise in local temperature to above the core temperature produces vasoconstriction in the fingers, an area where no thermal sweating takes place.

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