[Comparison of fentanyl and dexmedetomidine as an adjuvant to bupivacaine for unilateral spinal anesthesia in lower limb surgery: a randomized trial]. / Comparação de fentanil e dexmedetomidina como adjuvante à bupivacaína para raquianestesia unilateral em cirurgia de membros inferiores: estudo randômico.

BACKGROUND AND OBJECTIVES: One of the disadvantages of unilateral spinal anesthesia is the short duration of post-operative analgesia, which can be addressed by adding adjuvants to local anesthetics. The aim of current study was to compare the effects of adding dexmedetomidine, fentanyl, or saline to bupivacaine on the properties of unilateral spinal anesthesia in patients undergoing calf surgery. METHODS: In this double-blind clinical trial, 90 patients who underwent elective calf surgery were randomly divided into three groups. The spinal anesthetic rate in each of the three groups was 1mL bupivacaine 0.5% (5mg). In groups BD, BF and BS, 5µg of dexmedetomidine, 25µg of fentanyl and 0.5mL saline were added, respectively. The duration of the motor and sensory blocks in both limbs and the rate of pain during 24h after surgery were calculated. Hemodynamic changes were also measured during anesthesia for up to 90min. RESULTS: The duration of both of motor and sensory block was significantly longer in dependent limb in the BF (96 and 169min) and BD (92 and 166min) groups than the BS (84 and 157min) group. Visual Analog Scale was significantly lower in the two groups of BF (1.4) and BD (1.3), within 24h after surgery, than the BS (1.6) group. CONCLUSIONS: The addition of fentanyl and dexmedetomidine to bupivacaine in unilateral spinal anesthesia can increase the duration of the motor and sensory block in dependent limb and prolong the duration of postoperative pain. However, fentanyl is more effective than dexmedetomidine.

Comparison of fentanyl and dexmedetomidine as an adjuvant to bupivacaine for unilateral spinal anesthesia in lower limb surgery: a randomized trial / Comparação de fentanil e dexmedetomidina como adjuvante à bupivacaína para raquianestesia unilateral em cirurgia de membros inferiores: estudo randômico

Abstract Background and objectives One of the disadvantages of unilateral spinal anesthesia is the short duration of post-operative analgesia, which can be addressed by adding adjuvants to local anesthetics. The aim of current study was to compare the effects of adding dexmedetomidine, fentanyl, or saline to bupivacaine on the properties of unilateral spinal anesthesia in patients undergoing calf surgery. Methods In this double-blind clinical trial, 90 patients who underwent elective calf surgery were randomly divided into three groups. The spinal anesthetic rate in each of the three groups was 1 mL bupivacaine 0.5% (5 mg). In groups BD, BF and BS, 5 µg of dexmedetomidine, 25 µg of fentanyl and 0.5 mL saline were added, respectively. The duration of the motor and sensory blocks in both limbs and the rate of pain during 24 h after surgery were calculated. Hemodynamic changes were also measured during anesthesia for up to 90 min. Results The duration of both of motor and sensory block was significantly longer in dependent limb in the BF (96 and 169 min) and BD (92 and 166 min) groups than the BS (84 and 157 min) group. Visual Analog Scale was significantly lower in the two groups of BF (1.4) and BD (1.3), within 24 h after surgery, than the BS (1.6) group. Conclusions The addition of fentanyl and dexmedetomidine to bupivacaine in unilateral spinal anesthesia can increase the duration of the motor and sensory block in dependent limb and prolong the duration of postoperative pain. However, fentanyl is more effective than dexmedetomidine.

Resumo Justificativa e objetivos Uma das desvantagens da raquianestesia unilateral é a curta duração da analgesia pós-operatória, que pode ser abordada pela adição de adjuvantes aos anestésicos locais. O objetivo deste estudo foi comparar os efeitos da adição de dexmedetomidina, fentanil ou solução salina à bupivacaína sobre as propriedades da raquianestesia unilateral em pacientes submetidos à cirurgia de panturrilha. Métodos Neste ensaio clínico duplo-cego, 90 pacientes submetidos à cirurgia eletiva de panturrilha foram randomicamente divididos em três grupos. A quantidade de anestésico para a raquianestesia nos três grupos foi de 1 mL de bupivacaína a 0,5% (5 mg). Nos grupos BD, BF e BS, 5 µg de dexmedetomidina, 25 µg de fentanil e 0,5 mL de solução salina foram adicionados, respectivamente. Foram calculados a duração dos bloqueios motor e sensorial em ambos os membros e o escore de dor durante 24 horas após a cirurgia. As alterações hemodinâmicas também foram medidas durante a anestesia por até 90 minutos. Resultados A duração de ambos os bloqueios, motor e sensorial, foi significativamente maior no membro dependente nos grupos BF (96 e 169 min) e BD (92 e 166 min) do que no grupo BS (84 e 157 min). Os escores da escala visual analógica foram significativamente menores nos grupos BF (1,4) e BD (1,3) do que no grupo BS (1,6) nas 24 horas após a cirurgia. Conclusões A adição de fentanil e dexmedetomidina à bupivacaína em raquianestesia unilateral pode aumentar a duração dos bloqueios sensorial e motor no membro dependente e prolongar a duração da dor pós-operatória. Contudo, fentanil é mais eficaz do que dexmedetomidina.

Comparative analysis of the methods of anesthetic maintenance in patients with diabetes with the syndrome of diabetic foot requiring operative intervention.

OBJECTIVE: Introduction: In the present article we draw a comparison between such types of regional anesthesia (RA) as unilateral spinal anesthesia (USA), traditional spinal anesthesia (SA) and block anesthesia of peripheral nerve trunk (block anesthesia of sciatic nerve (BASN) on the side of operative intervention) during surgical treatment of patients with the syndrome of diabetic foot. The aim of the article is to compare effectiveness, reliability and safety of such methods of RA as unilateral and traditional spinal anesthesia, as well as block anesthesia of sciatic nerve on the side of operative intervention. PATIENTS AND METHODS: Materials and methods: 96 patients with the syndrome of diabetic foot, who received treatment in the department of purulent surgery, were examined. All patients underwent operative interventions of varying degrees of complexity depending on the nature and seriousness of damage degree of extremities, in terms of RA types under investigation. Effectiveness of regional block anesthesia, the time when anesthesia takes effect, duration and deepness were evaluated. RESULTS: Results: It should be noted that USA, as a variant of pain management during operations of foot, provides the most adequate level of surgical pain management in comparison with the other types of anesthesia. During block anesthesia of sciatic nerve more than half of patients are not provided with 100% surgical analgesia, which can lead to additional medicamentous analgosedation. According to the results obtained, pain sensitivity in patients after BASN is reliably higher than in patients after USA and SA in all stages of the study. CONCLUSION: Conclusions: RA is the main method of choice during operations on foot in comparison with the methods of general anesthesia. Unilateral spinal anesthesia is carried out with the use of smaller amount of anesthetic than traditional spinal anesthesia and block anesthesia of peripheral nerve trunk, which significantly reduces sympathectomy area and leads to the stable hemodynamic during the peri-operative period.

Anestesia espinal unilateral para cirugía ortopédica ambulatoria: evaluación de una dosis mínima de bupivacaína hiperbara asociada a lateralización: ¿es posible el éxito? / Unilateral spinal anaesthesis for orthopaedic ambulatory surgery: evaluation of a mininal dose of hyperbaric bupivacaine associated with side positioning: Is success posible?

INTRODUCCIÓN: la anestesia espinal unilateral (AEU) es una alternativa para el desarrollo de la cirugía ortopédica ambulatoria (COA). el OBJETIVO de este ensayo clínico fue el evaluar una dosis baja de bupivacaína hiperbara (BHB), asociada a fentanilo intratecal (FI) para obtención de AEU en COA. MATERIALES Y MÉTODOS: ensayo clínico, prospectivo, controlado en pacientes ASA I a II. la AEU se efectuó con el paciente en decúbito lateral (DL), con el lado operatorio hacia abajo, a nivel de L3-L4. se inyectó 5 mg de BHB 0,75% asociado a 20 µg de FI. se evaluó el bloqueo sensitivo (BS) y motor (BM) cada 3 minutos, los primeros 20 minutos y luego cada 15 minutos. Se midió el nivel máximo alcanzado, el tiempo de regresión a T12 y el tiempo de regresión de dos segmentos. se registró la incidencia de complicaciones. RESULTADOS: 50 pacientes fueron incluidos, 66% de sexo masculino. Se obtuvo anestesia unilateral en el 84% y BM total unilateral en el 86%. La altura del BS osciló entre T9 y T11. la duración del BS fue 116 min. (SD± 23). la regresión a T12 fue de 47 min (SD±19). No se encontró correlación entre talla, dosis y duración de bloqueo. ningún paciente necesitó anestesia general. 1 paciente presentó bradicardia. DISCUSIÓN: la AEU con dosis bajas de BHB asociado a FI es eficiente en COA. se obtuvo adecuados BS y BM en la mayoría de los pacientes. la AEU mostró ser confiable, permitiendo una alta precoz y segura.

INTRODUCTION: The unilateral spinal anesthesia (USA) is an alternative for orthopedic ambulatory surgery (OAS). The AIM of this study was to evaluate a low dose of hyperbaric bupivacaine (HB) associated with intrathecal fentanyl (ITF) to produce USA. MATERIALS AND METHODS: Prospective, controlled clinical trial in ASA I ­II patients. The USA was developed in lateral position with the operating side downwards between L3-L4 space with 5 mg of HB + 20 µg ITF. We evaluated sensitive level block (SB), motor level block (MB), maximum level obtained, discharge time (DT) and collateral effects incidence. RESULTS: 50 patients were included, 66% male. The USA was obtained in 84% and total BM was present in 86% of cases. The level obtained of SB was between T9-T11 and the duration was 116 min (SD± 23). No correlation was obtained between patients height, BH dose and block duration. 1 patient presented bradycardia. No general anesthesia was necessary. DISCUSSION: The USA with a low dose of HB and ITF it's safe to developed OAS. Only 11 min were necessary to obtain a good SB and MB.

Effect of spinal flexion and extension in the lateral decubitus position on the unilaterality of spinal anesthesia using hyperbaric bupivacaine.

BACKGROUND AND AIMS: Many unilateral lower limb orthopedic surgeries are conducted under unilateral spinal anesthesia with full flexion of spine and immediate extension after local anesthetic administration into the subarachnoid space. Studies have shown that extension of the spine in lateral decubitous position makes cauda equina to sink to the dependent side due to gravity. Continuous flexion of the spine causes sunken cauda equina to be suspended in the middle of the subarachnoid space increasing the possibility of unilateralization of the block. Hence, this study was carried out to assess the effect of flexion and extension in lateral decubitus position in unilateral spinal anesthesia. MATERIAL AND METHODS: Sixty patients posted for elective unilateral lower limb below knee orthopedic surgeries were randomly allocated into two groups-group F (flexion of spine) and group E (extension of spine). Using a 25-gauge Quincke spinal needle, 8 mg of 0.5% hyperbaric bupivacaine was injected over a period of 80 s at L3-L4 interspace. Patients were kept in flexion or extension according to the group they belong to after drug administration. After 15 min of lateral position in either group, patients were turned to supine position. Sensory blockade was assessed by loss of pinprick sensation and motor blockade by modified Bromage scale. RESULTS: Strict unilateral sensory block at 15th min was in 18 patients in flexion group compared with 11 patients in extension group which is statistically significant (p=0.03). At 60th min, there was no significant sensory unilaterality between the groups (p=0.06). A strict unilateral motor blockade at 15th min was also in 18 patients in group F and 11 patients in group E which was also statistically significant (p=0.04). At 60th min, seven patients in group F and three patients in group E had strict unilateral motor blockade which was also statistically significant (p=0.03). The maximum sensory level on the nondependent side was T10 in group F and T8 in group E, whereas it was T6 in both the groups on the dependent side. There was no difference in the two-segment regression of the sensory block, duration of sensory and motor blockade, the maximum level of the block, and hemodynamic status between the groups. CONCLUSION: Maintaining flexion of the spinal column for 15 min increases the likelihood of unilateral spinal block compared with extension of the spinal column during lateral decubitus positioning.

Comparison of two doses of hypobaric bupivacaine in unilateral spinal anesthesia for hip fracture surgery: 5 mg versus 7.5 mg.

INTRODUCTION: Hip fracture is a frequent and severe disease. Its prognosis depends on the perioperative hemodynamic stability which can be preserved by the unilateral spinal anesthesia especially with low doses of local anesthetics. This study aims to compare the efficacy and hemodynamic stability of two doses of hypobaric bupivacaine (7.5 mg vs 5 mg) in unilateral spinal anesthesia. METHODS: In this prospective, randomized, double-blind study, 108 patients scheduled for hip fracture surgery under unilateral spinal anesthesia were enrolled to receive either 5 mg (group 1) or 7.5 mg (group 2) of hypobaric bupivacaine. Spinal anesthesia was performed in lateral position. Patients' socio-demographic characteristics, hemodynamic profile, sensory and motor blocks parameters were recorded. RESULTS: Both groups were comparable regarding to demographic data. Two cases of failure occurred in group 1 and one case in group 2 corresponding to a comparable efficiency rates (96.29% and 98.14% respectively; p = 0.5). A higher mean onset and lower mean regression times of sensory block were significantly noted in group 1 (7.79±3.76 min vs 5.75±2.35 min, p < 0.001 and 91.29±31.55 min vs 112.77±18.77 min, p <0.001 respectively). Incidence of bilateralization (29.62% vs 87.03%, p < 0.001), incidence of hypotensive episodes (59.25% vs 92.59%, p < 0.001) and vascular loading (1481.48±411.65 ml vs 2111.11±596.10 ml, p < 0.001) were significantly higher in group 2. CONCLUSION: The dosage of 5mg of hypobaric bupivacaine in unilateral spinal anesthesia is as effective as the dosage of 7.5 mg with lower bilateralization incidence and better hemodynamic stability.

[Unilateral spinal anesthesia : Literature review and recommendations]. / Einseitige Spinalanästhesie : Literaturübersicht und Handlungsempfehlung.

Unilateral spinal anesthesia is a cost-effective and rapidly performed anesthetic technique. An exclusively unilateral block only affects the sensory, motor and sympathetic functions on one side of the body and offers the advantages of a spinal block without the typical adverse side effects seen with a bilateral block. The lack of hypotension, in particular, makes unilateral spinal anesthesia suitable for patients with cardiovascular risk factors e. g. aortic valve stenosis or coronary artery disease. Increasing numbers of surgical procedures are now being performed on an outpatient basis. Until now, spinal anesthesia has been considered unsuitable for this, not only because of the high incidence of intraoperative hypotension and postoperative urinary retention but also because of the prolonged postoperative stay before home discharge. This is not the case with unilateral spinal anesthesia: motor function returns rapidly, the incidence of urinary retention is extremely low, and patients are usually eligible for home discharge sooner than after bilateral spinal anesthesia or general anesthesia. The success of the technique depends on a number of factors. In addition to the local anesthetic, its concentration and dose, and the baricity of the injected solution, the shape of the spinal needle, the injection speed, the patient's position during injection, and the time the patient remains in this position after injection are equally important parameters. A number of intrathecally applied adjuvant drugs are used to give a more intense and/or longer-lasting block. For this review, we collated the published data on unilateral spinal anesthesia from journals with an impact factor greater than 1.0 and defined an optimized method for performing the technique. In order to achieve an exclusively unilateral block one should use 0.5 % hyperbaric bupivacaine injected at a rate of 0.33 ml/min or slower. During the injection and the following 20 min the patient should lie in the lateral decubitus position on the side intended for surgery with knees drawn to the chest. An injection of 5 mg (1 ml) hyperbaric bupivacaine 0.5 % provides an hour-long block to T 12, and a dose of 7.5 to 10 mg (1.5-2.0 ml) extends the block to T 6. Adding clonidine (0.5 to 1.0 µg/kg BW) to the injection prolongs the duration of the block to approximately two to three hours. During the 20-minute fixation period, the cephalad spread of the block can be influenced to a certain extent by raising or lowering the head of the table.

Effect of cooled hyperbaric bupivacaine on unilateral spinal anesthesia success rate and hemodynamic complications in inguinal hernia surgery.

PURPOSE: We hypothesized that cooling hyperbaric bupivacaine from 23 to 5 °C may limit the intrathecal spread of bupivacaine and therefore increase the success rate of unilateral spinal anesthesia and decrease the rate of hemodynamic complications. METHODS: A hundred patients scheduled for elective unilateral inguinal hernia surgery were randomly allocated to receive 1.8 ml of 0.5 % hyperbaric bupivacaine intrathecally at either 5 °C (group I, n = 50) or at 23 °C (group II, n = 50). Following spinal block at the L2-3 interspace, the lateral decubitus position was maintained for 15 min. Unilateral spinal anesthesia was assessed and confirmed at 15 and 30 min. The levels of sensory and motor block on the operative side were evaluated until complete resolution. RESULTS: The rate of unilateral spinal anesthesia at 15 and 30 min was significantly higher in group I (p = 0.015 and 0.028, respectively). Hypotensive events and bradycardia were significantly rarer in group I (p = 0.014 and 0.037, respectively). The density and viscosity of the solution at 5 °C was significantly higher than at 23 °C (p < 0.0001). Compared with group II, sensory block peaked later in group I (17.4 vs 12.6 min) and at a lower level (T9 vs T7), and two-segment regression of sensory block (76.4 vs 84.3 min) and motor block recovery was shorter (157.6 vs 193.4 min) (p < 0.0001). CONCLUSIONS: Cooling of hyperbaric bupivacaine to 5 °C increased the density and viscosity of the solution and the success rate of unilateral spinal anesthesia, and decreased the hemodynamic complication rate.

Optimal dose of hyperbaric bupivacaine 0.5% for unilateral spinal anesthesia during diagnostic knee arthroscopy.

OBJECTIVE: To determine the dose of hyperbaric bupivacaine 0.5% required for unilateral spinal anesthesia during diagnostic knee arthroscopy. PATIENTS AND METHODS: This prospective, randomized, clinical study was performed in 80 patients who were assigned to four groups to receive different doses of intrathecal hyperbaric bupivacaine (5 mg, 7.5 mg, 10 mg and 12.5 mg in Groups 1, 2, 3, and 4 respectively). Onset of sensory and motor block, hemodynamic changes, regression of motor block, and incidence of complications were recorded. RESULTS: Unilateral sensory block was reported in 90% and 85% of patients in Group 1 and Group 2, respectively, but not in any patient in Group 3 and Group 4. Unilateral motor block (modified Bromage scale 0) was reported in 95% of patients in Group 1, 90% in Group 2, and only 5% in Group 3, while no patient in Group 4 showed unilateral motor block. The time required for regression of motor block (Bromage scale 0) was prolonged with higher doses. The incidence of nausea, vomiting, and urine retention was similar in the study groups. CONCLUSION: Unilateral sensory and motor block can be achieved with doses of 5 mg and 7.5 mg hyperbaric bupivacaine 0.5% with a stable hemodynamic state. However, 7.5 mg of hyperbaric bupivacaine 0.5% was the dose required for adequate unilateral spinal anesthesia.

Effect of Intrathecal Fentanyl with Hyperbaric Bupivacaine on Unilateral Spinal Anesthesia for Knee Arthroscopy / 대한마취과학회지

BACKGROUND: Unilateral spinal anesthesia prolongs sensory blockade and provides hemodynamic stability. Intrathecal opioids enhance spinal anesthesia without prolonging motor recovery or hemodynamic side effects. The author evaluated the effect of intrathecal fentanyl on unilateral spinal blockade with hyperbaric bupivacaine for knee arthroscopy. METHODS: Thirty-six healthy patients undergoing unilateral knee arthroscopy randomly received unilateral spinal anesthesia with 0.5% hyperbaric bupivacaine 4 mg (Group I) or 0.5% hyperbaric bupivacaine 4 mg combined with fentanyl 10 microgram (Group II). A lateral decubitus position was maintained for 15 minutes after intrathecal injection. The level and duration of sensory and motor blockade were recorded. RESULTS: The regression time of sensory block by two segments on dependent site was prolonged on Group II more than Group I (P < 0.05). There was no significant difference between two groups in recovery time of sensory and motor block. Unilateral sensory block was observed in 18 patients in Group I (100%) and in 2 patients in Group II (11%). Hemodynamic side effects were minimal in both groups, but pruritus was observed in 6 patients in Group II (33%). CONCLUSIONS: Small dose of intrathecal fentanyl with bupivacaine unilateral spinal anesthesia prolonged the duration of sensory block on operated site, but did not increase side effects and the duration of motor block and recovery. But intrathecal fentanyl with bupivacaine made disturbance of successful unilateral spinal block by the sensory block of nonoperated site.

Unilateral Spinal Anesthesia with Hyperbaric Levobupivacaine and Bupivacaine for Lower Limb Surgery / 대한마취과학회지

BACKGROUND: Levobupivacaine is the isolated S-enantiomer of bupivacaine and may be a favorable alternative to bupivacaine. The author evaluated the clinical efficacy of levobupivacaine relative to bupivacaine in spinal anesthesia. METHODS: The author randomly allocated 40 ASA physical status I or II patients undergoing lower limb surgery to do unilateral spinal anesthesia with 8% glucose bupivacaine 4 mg (n = 20) or 8% glucose levobupivacaine 4 mg (n = 20). Spinal anesthesia was performed at the L3-4 interspace using a 25-gauge Whitacre spinal needle. The lateral decubitus position was maintained for fifteen minutes after injection. RESULTS: Thirty minutes after injection, unilateral sensory block was present in 60% and 40% of cases, and unilateral motor block was observed in 90% and 85% in levobupivacaine and bupivacaine group, respectively. Levobupivacaine group had no differences as compared to bupivacaine group for spinal block resolution. CONCLUSIONS: It was concluded that 8% glucose levobupivacaine 4 mg and 8% glucose bupivacaine 4 mg provided similar spinal block for lower limb surgery without hemodynamic unstability.

The Effect of Injection Speed of Local Anesthetic on Success Rate of Unilateral Spinal Anesthesia / 대한마취과학회지

BACKGROUND: The relationship between the injection speed of a local anesthetic and the success rate of unilateral spinal anesthesia has been a controversial issue. The aim of this thesis was to identify any significant effects of the drug injection speed on the success rate of unilateral spinal anesthesia. METHODS: Forty patients were randomly allocated into 2 groups, group R and S. The injection speed was 4 ml/min in group R (n = 20) and 1 ml/min in group S (n = 20). Hyperbaric 0.5% bupivacaine 10 mg was injected via a syringe pump. The drug was administered at the L3-4 intervertebral space with the patient in the lateral decubitus position, which was maintained for 20 minutes after the injection. A spinal sensory block was assessed by examining the temperature sensation using an alcohol-sponge. The motor block was evaluated using the modified Bromage scale and the dependent and non-dependent sides were compared. RESULTS: Significant differences (P<0.05) were observed in the success rate of unilateral motor paralysis (45% in group R vs 90% in group S). There were no significant blood pressure differences between the two groups 5, 10, 15, 30 and 60 minutes after injecting the hyperbaric 0.5% bupivacaine. CONCLUSIONS: The injection speed of local anesthetics is one of the crucial factors for achieving a unilateral spinal anesthesia. Therefore, it is important to maintain a slow injection speed of a local anesthetic in unilateral spinal anesthesia.

The Influence of Unilateral Spinal Anesthesia and Conventional Spinal Anesthesia on Sensitivity to Midazolam Sedation / 대한마취과학회지

BACKGROUND: Spinal anesthesia potentiates sedative drug effects. We speculated that an acute decrease in tonic afferent input by spinal anesthesia would decrease the level of consciousness and thereby increase susceptibility to sedative drugs. The experiments were approached with the assumption that the amount of sedative would reduce in the following order: first, the group without spinal anesthesia, second, the group with unilateral spinal anesthesia, and third, the group with conventional spinal anesthesia. METHODS: Patients in group 1 (n = 20) were given midazolam without spinal anesthesia and patients in group 2 (n = 20) received unilateral spinal anesthesia. Those patients who after 20 minutes had a sensory level of T9-11 and a motor block of 3 in dependent side, no sensory block, and a motor block of 0 in the non-dependent side were included. In group 3 (n = 20), patients received conventional spinal anesthesia, and those patients who after 20 minutes had a sensory level of T9-11 and a motor block of 3 were included. The amount of midazolam administered at 33microgram/kg/min to a Bispectral Index score (BIS) of 80 was measured. RESULTS: The dose of midazolam administered to a BIS of 80 was significantly lower in group 3 than in group 1 or group 2. CONCLUSIONS: The sensitivity of sedatives was in the following order: the group with conventional spinal anesthesia, the group with unilateral spinal anesthesia, and the group not administered spinal anesthesia.

The Characteristics of Clinical Anesthesia Based on the Duration of Lateral Decubitus in Low Dose Hyperbaric Bupivacaine Induced Unilateral Spinal Block / 대한마취과학회지

BACKGROUND: When attempting a unilateral spinal anesthesia, many factors must be considered including patient's position, density and amount of the local anesthetics, needle design, injection speed. We evaluated a duration of lateral decubitus with low dose hyperbaric bupivacaine for maximizing the benefit. METHODS: Hyperbaric 0.5% bupivacaine 6 mg was administered slowly through a 25-gauge Whitacre needle to 60 ASA 1-2 patients undergoing unilateral lower extremity surgery. The patients were randomly allocated to four groups based on the duration of lateral decubitus after spinal anesthesia: 5 minutes in Group I; 10 minutes in Group II; 15 minutes in Group III; 20 minutes in Group IV. Circulatory variables, sensory and motor block level were recorded. RESULTS: The circulatory variables were stable in all patients. In the Group I, the success rate of unilateral motor block was significantly lower than other groups. In the Group IV, the success rate of unilateral sensory block was significantly higher than group I. In the Group II, III, IV, the patient's satisfaction scores were significantly higher than Group I. CONCLUSIONS: When unilateral spinal anesthesia was attempted with 0.5% hyperbaric bupivacaine 6 mg, cardiovascular stability was achieved in the groups that patients are kept in a lateral decubitus for more than 5 minutes after spinal injection, and patient's higher satisfaction scores were achieved in the unilateral motor block and in the groups that patients are kept in a lateral decubitus for more than 15 minutes after spinal injection.