The effects of the Trendelenburg position and the Valsalva manoeuvre on internal jugular vein diameter and placement in children.

INTRODUCTION: We compared the effects of various surgical positions, with and without the Valsalva manoeuvre, on the diameter of the right internal jugular vein (RIJV). METHODS: We recruited 100 American Society of Anesthesiologists physical status class I patients aged 2-12 years. The patients' heart rate, blood pressure, peripheral oxygen saturation and end-tidal CO2 pressure were monitored. Induction of anaesthesia was done using 1% propofol 10 mg/mL and fentanyl 2 µg/kg, while maintenance was achieved with 2% sevoflurane in a mixture of 50/50 oxygen and air (administered via a laryngeal mask airway). The RIJV diameter was measured using ultrasonography when the patient was in the supine position. Thereafter, it was measured when the patient was in the supine position + Valsalva, followed by the Trendelenburg, Trendelenburg + Valsalva, reverse Trendelenburg, and reverse Trendelenburg + Valsalva positions. A 15° depression or elevation was applied for the Trendelenburg position, and an airway pressure of 20 cmH2O was applied in the Valsalva manoeuvre. During ultrasonography, the patient's head was tilted 20° to the left. RESULTS: When compared to the mean RIJV diameter in the supine position, the mean RIJV diameter was significantly greater in all positions (p < 0.001) except for the reverse Trendelenburg position. The greatest increase in diameter was observed in the Trendelenburg position with the Valsalva manoeuvre (p < 0.001). CONCLUSION: In paediatric patients, the application of the Trendelenburg position with the Valsalva manoeuvre gave the greatest increase in RIJV diameter. The reverse Trendelenburg position had no significant effect on RIJV diameter.

Do metoclopramide and ondansetrone alter mivacurium-induced neuromuscular blockade? - a randomised trial.

BACKGROUND: We aimed to investigate the effects of metoclopramide and ondansetrone on mivacurium neuromuscular blockade. METHODS: Seventy five, ASA I-II patients, aged 18-65 and scheduled for elective surgery requiring tracheal intubation were included in the study. The patients received metoclopramide 10 mg, ondansetrone 4 mg or normal saline 5 mL; group M, group O, group NS (n=25), respectively. Before anesthesia study drugs were administered in a volume of 5 mL. The level of plasma cholinesterase were obtained before and 5 minutes after the administration of study drugs and 5 minutes after the administration of mivacurium. Onset time, T25, T75, T25-75, T90 levels were compared with each other and differences between each patients were investigated. After recording T90, the study was terminated and surgery was started. RESULTS: Onset time was significantly shorter in group M, than the other two groups. Onset time in group O was significantly shorter than in group NS. In Group M T25, T75, T90 and recovery indices were significantly greater than in Group NS (p<0.001). In Group O T25, T75 were greater than Group NS (p<0.01 and p<0.05, respectively). In Group M T75, T90 and emergence indices were significantly higher than Group O (p<0.001, p<0.01, p<0.001, respectively). In Groups M and O, plasma cholinesterase levels decreased significantly (p<0.001) after administration of study drugs and mivacurium. Plasma cholinesterase also was reduced in Group NS 5 minutes after the administration of mivacurium (p<0.001). CONCLUSION: Ondansetrone is believed to be more reliable agent than metoclopramide when used with mivacurium.

Metoclopramida e ondansetrona alteram o bloqueio neuromuscular induzido por mivacurio? - um estudo randomizado / Do metoclopramide and ondansetrone alter mivacurium-induced neuromuscular blockade? - a randomised trial / La metoclopramida y la ondansetrona alteran el bloqueo neuromuscular inducido por mivacurio? - un estudio aleatorizado

Experiência: Objetivamos investigar os efeitos de metoclopramida e ondansetrona no bloqueio neuromuscular por mivacúrio. Métodos: Foram incluídos no estudo 75 pacientes ASA I-II, com idades entre 18 e 65 anos e agendados para cirurgia eletiva necessitando de intubação traqueal. Os pacientes receberam metoclopramida 10 mg, ondansetrona 4 mg ou salina normal 5 mL; grupo M, grupo O e grupo SN (n = 25) respectivamente. Antes da anestesia, os medicamentos em estudo foram administrados em um volume de 5 mL. O nível de colinesterase plasmática foram obtidos antes e 5 minutos depois da administração dos medicamentos em estudo e 5 minutos depois da administração de mivacúrio. Os tempos até o início e os níveis T25, T75, T25-75 e T90 foram comparados entre si, tendo sido investigadas as diferenças entre cada paciente. Depois de registrar T90, o estudo foi terminado, tendo início a cirurgia. Resultados: O tempo até o início foi significativamente mais breve no Grupo M versus os outros dois grupos. O tempo até o início no Grupo O foi significativamente mais breve versus grupo SN. No grupo M, T25, T75, T90 e os índices de recuperação foram significativamente maiores versus Grupo NS (p < 0,001). No Grupo O, T25 e T75 foram maiores versus Grupo NS (p < 0,01 e p < 0,05,respectivamente). No Grupo M, T75, T90 e índices de retorno da anestesia foram significativamente maiores versus Grupo O (p < 0,001, p < 0,01, p < 0,001, respectivamente). Nos Grupos M e O, os níveis plasmáticos de colinesterase diminuíram significativamente (p < 0,001). Depois da administração dos medicamentos em estudo e de mivacúrio. Houve também redução na colinesterase plasmática no Grupo NS 5 minutos após a administração de mivacúrio (p < 0,001). ...

Background: We aimed to investigate the effects of metoclopramide and ondansetrone on mivacurium neuromuscular blockade. Methods: Seventy five, ASA I-II patients, aged 18-65 and scheduled for elective surgery requiring tracheal intubation were included in the study. The patients received metoclopramide 10 mg, ondansetrone 4 mg or normal saline 5 mL; group M, group O, group NS (n = 25), respectively. Before anesthesia study drugs were administered in a volume of 5 mL. The level of plasma cholinesterase were obtained before and 5 minutes after the administration of study drugs and5 minutes after the administration of mivacurium. Onset time, T25, T75, T25-75, T90 levelswere compared with each other and differences between each patients were investigated. After recording T90, the study was terminated and surgery was started. Results: Onset time was significantly shorter in group M, than the other two groups. Onset time in group O was significantly shorter than in group NS. In Group M T25, T75, T90 and recovery indices were significantly greater than in Group NS (p < 0.001). In Group O T25, T75 were greater than Group NS (p < 0.01 and p < 0.05, respectively). In Group M T75, T90 and emergence indices were significantly higher than Group O (p < 0.001, p < 0.01, p < 0.001, respectively). In Groups M and O, plasma cholinesterase levels decreased significantly (p < 0.001) after administration of study drugs and mivacurium. Plasma cholinesterase also was reduced in Group NS 5 minutes after the administration of mivacurium (p < 0.001). Conclusion: Ondansetrone is believed to be more reliable agent than metoclopramide when used with mivacurium. .

Thoracic paravertebral block for video-assisted thoracoscopic surgery: single injection versus multiple injections.

OBJECTIVE: Thoracic paravertebral blocks (PVBs) have been shown to be effective for analgesia after video-assisted thoracoscopic surgery (VATS) with single- and multiple-injection techniques. The efficacy of single-injection PVB was compared with multiple-injection PVB on postoperative analgesia in VATS was studied. DESIGN: Prospective, randomized study. SETTING: Single university hospital. PARTICIPANTS: Fifty patients undergoing VATS. INTERVENTIONS: A nerve stimulator-guided PVB was performed in the sitting position before surgery using a solution of 20 mL 0.5% bupivacaine with 1:200,000 epinephrine by a single injection at T6 (group S, n = 25) or by 5 injections of 4 mL each at T4 to T8 (group M, n = 25). MEASUREMENTS AND MAIN RESULTS: A successful PVB was achieved in all patients. The times to perform the blocks were 6.8 ± 1.9 minutes in the S group and 17.9 ± 3.0 minutes in the M group (p < 0.001). The times to block onset were 8.3 ± 1.8 minutes in the S group and 7.2 ± 0.9 minutes in the M group (p = 0.014). The numbers of anesthetized dermatomes were 5.8 ± 0.8 for the S group and 6.6 ± 1.1 for the M group (p = 0.009). The postoperative pain scores and morphine consumption with patient-controlled analgesia were comparable in the two groups. There were no significant differences in times to the first mobilization and hospital discharge for two groups. Patient satisfaction with the analgesic procedure was greater in the S group (p < 0.05). No complications were attributed to the blocks. CONCLUSIONS: The two techniques provided comparable postoperative analgesia. However, single-injection PVB may represent an advantage over multiple-injection PVB in patients undergoing VATS, with greater patient satisfaction associated with a shorter procedure and the likelihood of decreased complications.

Comparison of two different doses of intrathecal levobupivacaine for transurethral endoscopic surgery.

OBJECTIVE: To evaluate the effects of two different spinal isobaric levobupivacaine doses on spinal anesthesia characteristics and to find the minimum effective dose for surgery in patients undergoing transurethral resection (TUR) surgery. MATERIALS AND METHODS: Fifty male patients undergoing TUR surgery were included in the study and were randomized into two equal groups: Group LB10 (n=25): 10 mg 0.5% isobaric levobupivacaine (2 ml) and Group LB15 (n=25): 15 mg 0.75% isobaric levobupivacaine (2 ml). Spinal anesthesia was administered via a 25G Quincke spinal needle through the L3-4 intervertebral space. Sensorial block levels were evaluated using the 'pin-prick test', and motor block levels were evaluated using the 'Bromage scale'. The sensorial and motor block characteristics of patients during intraoperative and postoperative periods and recovery time from spinal anesthesia were evaluated. RESULTS: In three cases in the Group LB10, sensorial block did not reach the T10 level. Complete motor block (Bromage=3) did not occur in eight cases in the Group LB10 and in five cases in the Group LB15. The highest sensorial dermatomal level detected was higher in Group LB15. In Group LB15, sensorial block initial time and the time of complete motor block occurrence were significantly shorter than Group LB10. Hypotension was observed in one case in Group LB15. No significant difference between groups was detected in two segments of regression times: the time to S2 regression and complete sensorial block regression time. Complete motor block regression time was significantly longer in Group LB15 than in Group LB10 (p<0.01). CONCLUSION: Our findings showed that the minimum effective spinal isobaric levobupivacaine dose was 10 mg for TUR surgery.

Intravenous dexmedetomidine, but not midazolam, prolongs bupivacaine spinal anesthesia.

PURPOSE: Midazolam has only sedative properties. However, dexmedetomidine has both analgesic and sedative properties that may prolong the duration of sensory and motor block obtained with spinal anesthesia. This study was designed to compare intravenous dexmedetomidine with midazolam and placebo on spinal block duration, analgesia, and sedation in patients undergoing transurethral resection of the prostate. METHODS: In this double-blind randomized placebo-controlled trial, 75 American Society of Anesthesiologists' I and II patients received dexmedetomidine 0.5 microg . kg(-1), midazolam 0.05 mg . kg(-1), or saline intravenously before spinal anesthesia with bupivacaine 0.5% 15 mg (n = 25 per group). The maximum upper level of sensory block and sensory and motor regression times were recorded. Postoperative analgesic requirements and sedation were also recorded. RESULTS: Sensory block was higher with dexmedetomidine (T 4.6 +/- 0.6) than with midazolam (T 6.4 +/- 0.9; P < 0.001) or saline (T 6.4 +/- 0.8; P < 0.001). Time for sensory regression of two dermatomes was 145 +/- 26 min in the dexmedetomidine group, longer (P < 0.001) than in the midazolam (106 +/- 39 min) or the saline (97 +/- 27 min) groups. Duration of motor block was similar in all groups. Dexmedetomidine also increased the time to first request for postoperative analgesia (P < 0.01 compared with midazolam and saline) and decreased analgesic requirements (P < 0.05). The maximum Ramsay sedation score was greater in the dexmedetomidine and midazolam groups than in the saline group (P < 0.001). CONCLUSION: Intravenous dexmedetomidine, but not midazolam, prolonged spinal bupivacaine sensory blockade. It also provided sedation and additional analgesia.