Hahck Soo Park

Effect of intraoperative infusion of ketamine on remifentanil-induced hyperalgesia.

Background Opioid induced hyperalgesia (OIH) is related with high opioid dosage, a long duration of opioid administration, and abrupt discontinuation of infused opioids in anesthetic settings. Ketamine is known to attenuate OIH efficiently, but methods of administration and methods to quantify and assess a decrease in OIH vary. We demonstrated the existence of remifentanil-induced hyperalgesia and investigated the ability of ketamine to attenuate OIH. Methods Seventy-five patients undergoing laparoscopic gynecologic surgery under remifentanil-based anesthesia were assigned to one of the following groups: (1) group RL (remifentanil 0.05 µg/kg/min), (2) group RH (remifentanil 0.3 µg/kg/min), or (3) group KRH (remifentanil 0.3 µg/kg/min + ketamine 0.5 mg/kg bolus with 5 µg/kg/min infusion intraoperatively). Desflurane was administered for maintenance of anesthesia to target bispectral index scores (40-60) and hemodynamic parameters (heart rate and blood pressure < ± 20% of baseline values). All parameters related to OIH and its attenuation induced by ketamine were investigated. Results There was no significant difference among the three groups related to demographic and anesthetic parameters except the end-tidal concentration of desflurane. Additional analgesic consumption, numerical rating scale scores at 6 and 24 h, and cumulative fentanyl dose were significantly higher in group RH than in the other two groups. The value difference of the Touch-Test sensory evaluation was significantly higher negative in group RH than in the other two groups. Conclusions Remifentanil-induced hyperalgesia is significantly attenuated by intraoperative bolus and infusion of ketamine. Ketamine also decreased tactile sensitization, as measured by Touch-Test sensory evaluation.

Cervical transforaminal epidural block using low-dose local anesthetic: a prospective, randomized, double-blind study.

OBJECTIVES Intra-arterial injections of local anesthetic during cervical transforaminal epidural block (TFEB) can cause rare but fatal neurologic complications. We hypothesized that using a dose of local anesthetic lower than seizure threshold during cervical TFEB would not be associated with seizure activity in cases of accidental intra-arterial injection. METHODS Patients were randomized to one of two groups: group I received injections of 1 mL of 1% lidocaine mixed with dexamethasone 2.5 mg (n = 15), and group II received 1 mL of 0.125% lidocaine mixed with dexamethasone 2.5 mg (n = 15). When the numeric rating scale (NRS) for pain was greater than 3, cervical TFEBs were performed three times at 2-week intervals. Patients were evaluated up to 3 months. RESULTS Thirty patients with cervical radicular pain were enrolled in this study. The NRS pain score on the day of procedure and at 2 weeks, 4 weeks, 6 weeks, and 3 months following the initial procedure were similarly significantly reduced in both groups. The total number of procedures performed and the outcomes evaluated according to Odoms criteria at the 3-month follow-up visit were not different between groups. Overall, 73.3% and 80% patients in groups I and II, respectively, rated the degree of their symptom relief as excellent or good. CONCLUSION Cervical TFEB performed using 0.125% lidocaine with dexamethasone achieved similar satisfactory effects as 1% lidocaine with dexamethasone for the treatment of cervical radicular pain. Therefore, the use of low-dose lidocaine with dexamethasone is reasonable for cervical TFEB, as this may reduce the incidence of rare but fatal complications.

The effects of a forceful transforaminal epidural steroid injection on radicular pain: a preliminary study.

Background Lumbar transforaminal epidural steroid injections (TFESIs) are performed to provide symptom relief in patients with radicular pain. Recent articles suggested that injected volume itself have analgesic effects and higher volumes are associated with better outcomes. To date, few studies have been conducted to investigate the effects of volume. Therefore, well-designed controlled studies were necessary to confirm the effect of volume itself on pain relief. The purpose of this study was to examine the effectiveness of a forceful saline injection on lumbar TFESI using non-particulate steroids. Methods Fifty consecutive patients with lumbar radicular pain were enrolled. The participants were allocated into one of two groups: dexamethasone with volume (Group DV) and dexamethasone alone (Group DO). The volume was delivered by a forceful injection of 5ml of normal saline. The primary end-point for this study was a VAS pain score and modified MacNab score indicating the rate of effectiveness at the four-week follow-up. Results There were no significant post-procedural VAS differences between two groups (P = .252). The effectiveness rate among the patients was 47.8% in DV group, 34.8% in DO group, measured by modified MacNab score. The difference was not statistically significant (P = .117). Conclusions A forceful saline injection did not have a significant effect during the treatment of radicular pain. Further studies with greater volumes and with additional techniques would offer a more conclusive perspective.

Piriformis muscle: clinical anatomy with computed tomography in korean population.

Background The objective was to evaluate the distance from the skin and the diameter of the piriformis muscle and their relationship to the body mass index (BMI). Methods The study was a prospective study involving 60 patients. Patients were prepared on a radiological table in the prone position. Several images were obtained of each. In this view, the distance between the subcutaneous tissue and the piriformis muscle, and the diameter of the piriformis, were measured at three points (medially to laterally). Results The distance to the piriformis from the skin was 6.6 ± 0.9 cm, 6.3 ± 0.8 cm, and 5.2 ± 0.9 cm in terms of the lateral, center, and medial measurement, respectively. The center of the piriformis had a greater diameter with 1.7 ± 0.4 (0.9-2.5) cm. The distance to the piriformis increased with BMI. Conclusions This study shows that the lateral of the piriformis muscle has a relatively greater distance from the skin. The center of the piriformis showed a greater diameter than other two portions. We found that the distance of the piriformis from subcutaneous tissues was correlated with BMI, but the diameter of the piriformis was not affected by BMI. These measurements can be used as a reference for determining the piriformis injection site in patients with piriformis syndrome.

A Modified Approach of Percutaneous Endoscopic Lumbar Discectomy (PELD) for Far Lateral Disc Herniation at L5-S1 with Foot Drop

Foraminal or extraforaminal Far Lateral Disc Herniations (FLDH) extending into or beyond the foraminal zone have been recognized as between 7-12% of all lumbosacral disc herniations. Conventional posterior laminectomy may not provide good access to a herniation that lies far lateral to the lateral margin of the pedicle. Use of the endoscopic technique through a percutaneous approach to treat such FLDH patients can decrease the surgical morbidity while achieving better outcomes. We made an effort to utilize the advantages of percutaneous endoscopic lumbar discectomy (PELD) and to determine the appropriate approach for FLDH at the level between the 5th Lumbar and first Sacral vertebrae(L5-S1). The authors present a case of an endoscopically resected lumbar extruded disc of the left extraforaminal zone with superior foraminal migration at the level of L5-S1, which had led to foot drop, while placing the endoscope in the anterior epidural space without facetectomy.

The effect of stellate ganglion block on intractable lymphedema after breast cancer surgery.

Lymphedema of the upper limb after breast cancer surgery is a disease that carries a life-long risk and is difficult to cure once it occurs despite the various treatments which have been developed. Two patients were referred from general surgery department for intractable lymphedema. They were treated with stellate ganglion blocks (SGBs), and the circumferences of the mid-point of their each upper and lower arms were measured on every visit to the pain clinic. A decrease of the circumference in each patient was observed starting after the second injection. A series of blocks were established to maintain a prolonged effect. Both patients were satisfied with less swelling and pain. This case demonstrates the benefits of an SGB for intractable upper limb lymphedema.

Vertebral level of Tuffier's line measured by ultrasonography in parturients in the lateral decubitus position

Background It is known that Tuffiers line intersects the spine at the L4 spinous process or at the L4-L5 intervertebral space. Full term parturient women undergo various physical changes. Therefore, determining the vertebral level with Tuffiers line based on palpation inevitably is not very accurate. The aim of this study was to use ultrasound to verify the difference between vertebral levels for the palpated Tuffiers line in parturient and non-parturient women in the lateral decubitus position. Methods We consecutively enrolled 40 parturient women at 37-41 weeks of gestation and 40 non-parturient women scheduled for regional anesthesia. In the left lateral position, the location of the vertebra was identified using ultrasonography. We marked every intervertebral space from L5 to L2 vertebra, divided each spinous process into two equal parts, and numbered the spaces sequentially from 1 to 9. We drew a Tuffiers line by palpating, recorded the vertebral level that this line intersected. Results The mean value of an arbitrary number of vertebral level of Tuffiers line was 6.4 ± 0.9 in the non-pregnant group and this represents L4-lower vertebral level. In the pregnant group, the mean value was 3.0 ± 1.0 which represents L3-lower vertebral level. There was a significant difference between the two groups (P < 0.05). Conclusions We compared using an available ultrasound technique the vertebral levels intersected by the palpated Tuffiers line between parturient and non-parturient women and found that the vertebral levels were more cephalad in the parturient women compared to the non-parturient women.

Successful Treatment of Severe Sympathetically Maintained Pain Following Anterior Spine Surgery

Sympathetic dysfunction is one of the possible complications of anterior spine surgery; however, it has been underestimated as a cause of complications. We report two successful experiences of treating severe dysesthetic pain occurring after anterior spine surgery, by performing a sympathetic block. The first patient experienced a burning and stabbing pain in the contralateral upper extremity of approach side used in anterior cervical discectomy and fusion, and underwent a stellate ganglion block with a significant relief of his pain. The second patient complained of a cold sensation and severe unexpected pain in the lower extremity of the contralateral side after anterior lumbar interbody fusion and was treated with lumbar sympathetic block. We aimed to describe sympathetically maintained pain as one of the important causes of early postoperative pain and the treatment option chosen for these cases in detail.

Plasma Concentrations of Morphine during Postoperative Pain Control

Background Morphine has been commonly used for postoperative pain control. We measured plasma concentrations of morphine and compared the efficacy and safety of continuous epidural analgesia (CEA) using morphine-bupivacaine with intravenous patient controlled analgesia (IV-PCA) with morphine for 48 hrs after the end of the operation. Methods Nineteen patients undergoing Miles operation were assigned to receive a morphine loading dose of 5 mg followed by IV-PCA with 0.1% morphine (IV-PCA group, n = 9) or a morphine loading dose of 2 mg and 0.125% bupivacaine 10 ml, followed by CEA with 0.004% morphine and 0.075% bupivacaine at a rate of 5 ml/hr (CEA group, n = 10). The plasma concentrations of morphine were measured and visual analog scales (VAS) for pain were recorded at 1, 6, 12, 24, and 48 hr postoperatively and the effects on respiration and any other side effects were noted. Results The mean maximal and minimal levels of plasma morphine were 40.2 ± 21.2 ng/ml and 23.4 ± 9.7 ng/ml for the IV-PCA group and 11.8 ± 3.5 ng/ml and 8.2 ± 1.9 ng/ml for the CEA group, respectively. Resting and dynamic pain scores were significantly lower in the CEA group than in the IV-PCA group. There were no significant differences for the effects on respiration and for any side effects between the two groups. Conclusions We evaluated plasma concentrations of morphine with CEA using morphine-bupivacaine and IV-PCA using morphine for the postoperative pain control. The CEA group had better postoperative analgesia than that of the IV-PCA group and the incidence of side effects were not significantly different between the two groups.

The effect of head rotation on efficiency of ventilation and cuff pressure using the PLMA in pediatric patients

Background This study examined whether changing the head position from neutral to side can affect expiratory tidal volume (TV) and cuff pressure when the appropriate sizes of a Proseal™ Laryngeal Mask Airway (PLMA)-depending on the body weight -are used in pediatric patients during pressure controlled ventilation (PCV). Methods Seventy-seven children (5-30 kg) were divided into three groups according to their body weight, PLMA#1.5 (group I, n = 24), #2 (group II, n = 26), and #2.5 (group III, n = 27). After anesthesia induction, a PLMA was placed with a cuff-pressure of 60 cmH2O. The TV and existence of leakage at the peak inspiratory pressure (PIP) of 20 cmH2O, and the appropriate PIP for TV 10 ml/kg were examined. Upon head rotation to the left side, the TV, PIP, cuff pressure changes, and the appropriate PIP to achieve a TV 10 ml/kg were evaluated. Results Head rotation of 45 degrees to the left side during PCV caused a significant increase in cuff pressure and a decrease in TV, and there was no definite leakage. Changes in PIP and TV were similar in the three groups. The cuff pressure increased but there was no significant difference between the three groups. Conclusions Although cuff pressure and TV of the PLMA were changed significantly after turning the head from the neutral position to the side, a re-adjustment of the cuff pressure and PIP to maintain a TV of 10 ml/kg can make the placed PLMA useful and successful in pediatric patients under general anesthesia.