Caudal ropivacaine and bupivacaine for postoperative analgesia in infants undergoing lower abdominal surgery.

OBJECTIVE: To compare the postoperative analgesic efficacy of ropivacaine 0.175% and bupivacaine 0.175% injected caudally into infants for lower abdominal surgery. METHODS: Eighty infants, aged 3-12 months, ASA I-II scheduled to undergo lower abdominal surgery were randomly allocated to one of the two groups: Group R received 1ml.kg(-1) 0.175% ropivacaine and Group B received 1ml.kg(-1) 0.175% bupivacaine via caudal route. Postoperative analgesia, sedation and motor block were evaluated with modified objective pain scale, three-point scale and modified Bromage scale respectively. Postoperative measurements including mean arterial pressure (MAP), heart rate (HR), pain (OPS), sedation and motor block score were recorded for four hours in the postoperative recovery room. Parents were contacted by telephone after 24 hours to question duration of analgesia and side effects. RESULTS: No significant differences were found among the groups in demographic data, MAP, HR, OPS and sedation scores during four hours postoperatively. The duration of analgesia was 527.5±150.62 minutes in Group R, 692.77±139.01 minutes in Group B (p=0.004). Twelve (30%) patients in Group R, 16 (40%) patients in groupB needed rescue analgesics (p=0.348). Rescue analgesics were administered (1 time/2 times) (9/3) (22.5/7.5%) in Group R and 16/0 (40/0%) in Group B, where no statistically significant difference was determined between the groups (p=0.071). Motor blockade was observed in 7 (17.5%) patients in Group R, and 8 (20%) patients in Group B (p=0.774). CONCLUSION: This study indicated, that a concentration of 0.175% ropivacaine and 0.175% bupivacaine administered to the infants via caudal route both provided effective and similar postoperative pain relief in infants, who underwent lower abdominal surgery.

A novel approach for anterior sciatic nerve block: cadaveric feasibility study.

BACKGROUND: Sciatic nerve block is a commonly used technique for providing anesthesia and analgesia to the lower extremity. It is classically performed through posterior or lateral approaches. However, an anterior approach should be considered in certain conditions where patient positioning would be complicated. The success rate of the sciatic nerve block with previously defined approaches has been reported to be low, however, the complication rate with such approaches has been found to be high. Therefore, we aimed to conduct an anatomical study defining a new anterior approach to block the sciatic nerve and also to examine if the femoral nerve can be blocked via the same approach. METHODS: Initially, various landmarks and practical measurements were examined on 11 lower extremities. Eight of the lower extremities were used for defining the best approach to the sciatic nerve anteriorly. Once defined, Indian ink was injected into two cadaveric extremities with an anesthetic needle through such an approach. The route of the needle was evaluated via dissection and we observed whether the ink stained the sciatic nerve or injured regional neurovascular structures. The remaining extremity was cut axially to observe the route of the needle after injection. RESULTS: The ideal site of needle insertion was found to be 4-5 cm distal to the inguinal crease and 1-2 cm lateral to the femoral artery. On average, this point corresponded to a point located 8.0 ± 0.7 cm distal to a perpendicular line drawn midway through the straight line connecting the anterior superior iliac spine (ASIS) and the pubic tubercle (PT). The distance of this point to the straight line drawn between the ASIS and PT was approximately equal to half the distance of this line. CONCLUSION: The technique described herein appears anatomically safe with a lower risk of damage to major neurovascular structures. Additionally, the femoral nerve can be blocked simultaneously to obtain a larger area of anesthesia of the lower limb.

Blood gas changes in patients undergoing laryngeal microsurgery.

BACKGROUND: The aim of this prospective, single-blind study was to assess the variations in the blood levels of PaO(2), PaO(2)/FiO(2), PaCO(2), and acid-base balance of patients undergoing laryngeal microsurgery under general anesthesia using small-bore endotracheal tubes. METHODS: 25 male patients were intubated with endotracheal tubes of 5.5-mm-inner diameter and fifteen female patients were intubated with endotracheal tubes of 5-mm-inner diameter during surgery. PaO(2)/FiO(2), PaO(2), PaCO(2), percentage saturation of O(2) and HCO(3), and pH levels were monitored before surgery and at 15-min intervals during laryngeal microsurgery. Respiratory function's values (dead space, peak inspiratory pressure (PIP) and dynamic compliance) were recorded every 15 min throughout laryngeal microsurgery. RESULTS: No significant differences were observed between the pre- and intra-operative values of percentage saturation of O(2), PaO(2)/FiO(2) and HCO(3) until 120th min. There was no significant difference in respiratory function's values intraoperatively. Under anesthesia, PaO(2) levels significantly increased when compared with preoperative values. Another significant increase was observed in PaCO(2) levels after the 60th min. However, compared with preoperative values, pH levels significantly decreased under anesthesia at the 105th and 120th min. CONCLUSION: Laryngeal microsurgery under general anesthesia can be performed using small-bore endotracheal tubes. This is not likely to have any adverse effects on a patient's blood gases and acid-base balance unless the operation lasts longer than 105 min.