RESUMEN
BACKGROUND: A limitation of Bier's block or i.v. regional anaesthesia (IVRA) is tourniquet pain. We hypothesized that tourniquet placement on the forearm vs upper arm during IVRA for distal upper extremity surgery may result in less tourniquet pain, lower the need for analgesic interventions, and decrease post-anaesthesia care unit (PACU) admission. METHODS: Patients for distal upper extremity surgery were randomized into upper or forearm single-cuff tourniquet placement. IVRA was either performed with 15 ml of 2% lidocaine and 20 mg ketorolac in the upper group or 8 ml of 2% lidocaine and 10 mg ketorolac in the forearm group. Vital signs and visual analogue scale (VAS) score were recorded. If VAS score was >4, 50 µg fentanyl was injected. If the patient had VAS scores >6 with fentanyl, deep sedation with propofol was administered. RESULTS: Twenty-eight subjects were in each group. There were no significant differences in patient characteristics, tourniquet time, or pressure between the groups. Ten patients in the forearm vs 27 in the upper arm group had a VAS score >4. The mean fentanyl use was 30 µg in the forearm group vs 104 µg in the upper arm group. One patient in the forearm group required propofol vs 22 in the upper arm group. PACU bypass to phase 2 recovery occurred 19 times in the forearm group vs zero times in the upper arm group (P<0.0001). CONCLUSIONS: Our results indicate that the placement of the tourniquet on the forearm resulted in less discomfort, fewer sedation interventions, and greater likelihood of bypassing the PACU when compared with upper arm tourniquet.
Asunto(s)
Anestesia de Conducción/métodos , Anestesia Intravenosa/métodos , Dolor Postoperatorio/etiología , Torniquetes/efectos adversos , Extremidad Superior/cirugía , Adulto , Anciano , Brazo , Femenino , Antebrazo , Humanos , Masculino , Persona de Mediana Edad , Dimensión del Dolor/métodos , Dolor Postoperatorio/prevención & control , Adulto JovenRESUMEN
BACKGROUND: Many studies demonstrate an association between brain damage and the extracellular release of catecholamines and amino acids during cerebral ischemia. While the clinical value of hypothermia during periods of compromised cerebral blood flow and oxygen delivery is well established, the role of anesthetic agents is less clear. Furthermore, the interaction between these agents and hypothermia remains to be elucidated. The purpose of this study was to examine the interactive effects of temperature, sodium thiopental (STP) and etomidate (ETOM) on extracellular neurotransmitter accumulation in the rat corpus striatum during cerebral ischemia. METHODS: Animals were randomly assigned to one of six subgroups: normal saline (NS-norm, pericranial t approximately equal to 37 degrees C, and NS-hypo, t=30 degrees C), etomidate (ETOM-norm and ETOM-hypo), and sodium thiopental (STP-norm and STP-hypo). Microdialysis probes were inserted into the corpus striatum. Dopamine (DA), glutamate, 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) levels were measured. At zero minutes, animals received a 10-min infusion of STP (3 mg x kg(-1) x min(-1)), ETOM (0.6 mg x kg(-1) x min(-1)), or NS. Prior to ischemia, animals were given either intravenous STP (10 mg x kg(-1)), ETOM (3 mg x kg(-1)), or NS in bolus form. Each animal was then subjected to 10 min of forebrain ischemia (Is1) followed by a reperfusion interval (Rep1). The entire sequence was then repeated. RESULTS: There were significant interactions between temperature and drug for DA (Is1, P=0.006, Is2, P=0.032) and its metabolites (DOPAC, Is1 P=0.01, HVA, Is1 P=0.03), and for glutamate (Is1, P=0.03, Is2 P=0.06). The nature of this interaction differed for DA and glutamate. The reduction in DA accumulation seen during hypothermia was offset by the addition of either STP or ETOM, whereas the addition of these drugs did not affect the reduced glutamate levels seen with hypothermia. During normothermia, STP and ETOM resulted in diminished DA accumulation compared to controls, yet they increased the accumulation of extracellular glutamate. CONCLUSIONS: Consistent with other studies, hypothermia was associated with diminished extracellular DA concentrations during forebrain ischemia. However, depending on the temperature condition, the addition of STP or ETOM in our forebrain ischemia model led to unexpected findings. The administration of these agents during normothermia diminished ischemia-induced DA accumulation yet resulted in significantly higher concentrations of extracellular glutamate. In contrast, STP and ETOM during hypothermia were noted to significantly offset the DA-reducing effects of hypothermia.
Asunto(s)
Anestésicos Intravenosos/farmacología , Isquemia Encefálica/metabolismo , Cuerpo Estriado/metabolismo , Dopamina/metabolismo , Etomidato/farmacología , Ácido Glutámico/metabolismo , Hipotermia Inducida , Tiopental/farmacología , Ácido 3,4-Dihidroxifenilacético/metabolismo , Animales , Presión Sanguínea , Isquemia Encefálica/fisiopatología , Dióxido de Carbono/sangre , Cromatografía Líquida de Alta Presión , Ácido Homovanílico/metabolismo , Concentración de Iones de Hidrógeno , Masculino , Microdiálisis , Prosencéfalo/irrigación sanguínea , Ratas , Ratas Endogámicas WKY , ReperfusiónRESUMEN
Long saphenous vein stripping (LSVS) surgery is often used to treat varicose veins. We tested the hypothesis that femoral nerve block (FNB) with genitofemoral nerve infiltration provides sufficient analgesia and superior recovery characteristics to spinal anesthesia for LSVS procedures in the ambulatory setting. Thirty-six patients were randomized to receive FNB with 30 mL of 3% alkalinized chloroprocaine, and 32 patients received spinal anesthesia with 65 mg of 5% hyperbaric lidocaine. Data collected included patient demographics, time required for induction of and recovery from anesthesia, postoperative anesthesia complications, and patient report of pain severity after the operation. During a follow-up call, a blinded observer noted the onset of any complications, the requirement for analgesics, and the patients' satisfaction with the anesthetic technique. Patients in the FNB group had significantly faster recovery (P < 0.01) and lower incidences of pain (P < 0.05) and complications (P < 0.05) than the patients in the spinal group. All patients who received FNB indicated that they would choose this type of anesthesia in the future, whereas five (15%) patients in the spinal group would refuse spinal anesthesia in the future (P < 0.01). We conclude that FNB is an excellent anesthetic choice for LSVS.
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Anestesia Raquidea , Nervio Femoral , Bloqueo Nervioso , Vena Safena/cirugía , Várices/cirugía , Adulto , Anciano , Procedimientos Quirúrgicos Ambulatorios , Femenino , Humanos , Masculino , Persona de Mediana EdadRESUMEN
Sciatic nerve block in the popliteal fossa is associated with a highly variable success rate. Frequently, anesthesia is profound in the distribution of both the tibial (TN) and common peroneal nerves (CPN), although the response to nerve stimulation or paresthesia is obtained in the distribution of one division of the nerve. However, anesthesia in the distribution of only one division of the nerve is also a common occurrence under apparently identical clinical circumstances. Looking for a possible role of a common epineural sheath in these phenomena, we injected dye into the epineural sheath of the tibial nerve in 10 cadaver legs and observed its spread within the sheath. Injections of 15 mL and 30 mL of the dye resulted in a proximal spread of 147 +/- 34 mm and 172 +/- 50 mm, respectively, from the injection point 10 cm below the popliteal fossa crease. In a majority of the legs, the dye reached the division of the sciatic nerve in the popliteal fossa, bathing both the TN and CPN. Gross inspection and histologic examination of the sciatic nerve specimens revealed a common epineural sheath enveloping the TN and CPN. The presence of the common epineural sheath and its characteristics may have important clinical implications for sciatic nerve blockade in the popliteal fossa.
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Bloqueo Nervioso , Nervio Ciático , Nervio Tibial/anatomía & histología , Humanos , Lactante , Nervio Peroneo/anatomía & histología , Nervio Ciático/anatomía & histologíaRESUMEN
STUDY OBJECTIVE: To compare a combination of peripheral nerve blocks with spinal anesthesia in ambulatory patients undergoing short saphenous vein stripping. DESIGN: Prospective, randomized study. SETTING: University hospital. PATIENTS: 28 ASA physical status l and II ambulatory surgery patients undergoing short saphenous vein stripping. INTERVENTIONS: 14 patients received a popliteal block (sciatic nerve block at the popliteal fossa) using 30 ml of alkalinized 3% chloroprocaine and a posterior cutaneous nerve of the thigh block with 10 ml of 1% lidocaine. The 14 patients who were randomized to the spinal anesthesia group received 65 mg of 5% hyperbaric lidocaine. MEASUREMENTS AND MAIN RESULTS: There were no significant differences in age and gender between the two groups (mean age 53 +/- 13 years, 8 men and 20 women). Patients in the peripheral nerve block group recovered significantly faster in phase 1 of the postanesthesia care unit (PACU) (67 +/- 10 min vs. 122 +/- 50 min, p < 0.01) and were discharged home sooner (222 +/- 53 min vs. 294 +/- 69 min, p < 0.01) than the patients in the spinal anesthesia group. CONCLUSIONS: The combination of popliteal and posterior cutaneous nerve of the thigh blocks provided adequate anesthesia and a faster recovery profile with a similar subjective acceptance of both anesthetic techniques in ambulatory patients undergoing short saphenous vein stripping in the prone position.
Asunto(s)
Procedimientos Quirúrgicos Ambulatorios , Anestesia Raquidea , Bloqueo Nervioso , Vena Safena/cirugía , Procedimientos Quirúrgicos Vasculares , Método Doble Ciego , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Piel/inervación , Muslo/inervaciónRESUMEN
BACKGROUND AND OBJECTIVES: The disadvantage of the classic posterior approach to block of the sciatic nerve at the knee level (popliteal nerve block [PNB]) is the need to position a patient in the prone position for performance of the block. In this study on cadavers, a lateral approach to the popliteal nerve in the supine position was investigated, and some anatomic considerations of relevance to popliteal nerve block were addressed. METHODS: In 19 cadaver right legs, the lateral approach to PNB was simulated with a needle, introduced in the groove between the biceps femoris and vastus lateralis muscles 7 cm above the knee, at either 30 degrees or 60 degrees relative to the horizontal plane, and 1 mL of dye solution was injected through the needle. After dissection of the popliteal fossa, the position of the solidified bolus of dye in relation to the popliteal nerve was determined. Additionally, the dye was injected into the popliteal nerve sheath, and the spread of the dye and continuity of the sheaths were determined. RESULTS: In 10 legs, the lateral approach was attempted at a 30 degrees angle and in 9 legs at a 60 degrees angle. The solidified injectates at 30 degrees were closely distributed anterolaterally to the nerve, while injectates at 60 degrees tended to be further from the nerve and scattered along its posterolateral aspect (P = .02). The dye injected into the nerve sheaths traveled 5 to 10 cm within the sheath, surrounding both main divisions of the popliteal nerve, the tibial and the common peroneal nerve. CONCLUSION: A lateral approach to the popliteal nerve with insertion of the needle at a 30 degrees angle relative to the horizontal plane results in predictable approximation of the needle tip to the popliteal nerve. The results also suggest the existence of a continuous neural sheath encompassing the popliteal nerve and its main branches. This may have clinical implications similar to those in perivascular neuronal block.