Localization of the trunk muscles using musculoskeletal ultrasound guidance for pedicle screw stimulation during spine surgery.

The precise placement of recording electrodes at the relevant myotome is mandatory while performing pedicle screw stimulation (PSS) during spine surgery; however, their placement at trunk muscles is challenging. This study aimed to determine whether ultrasound guidance is useful for trunk muscle localization for PSS during spine surgery. A retrospective clinical study was conducted from a prospective database. Eighty-four patients eligible for spine surgery were recruited. Ultrasound was used to localize the intercostal, rectus abdominis, and internal oblique and psoas muscles if pedicle screw placement was performed at T3 to L1. After the operation, patients were examined for any new neurological deficits related to this procedure, and computed tomography was performed to check screw position if indicated. Four to 22 pedicle screws were used for spinal fixation. The threshold of stimulus to obtain a compound muscle action potential ranged from 1.29 to >20mA during PSS. Six of our patients sustained new postoperative deficits, and only one case was related directly to pedicel screw misplacement. Loss of motor evoked potential (MEP) over both the lower limbs was noted during pedicle screw placement, and the stimulus threshold during PSS were 1.29mA at the left T9 and 3.8mA at the right T5 level. MEP remained absent at the end of surgery despite removal of those two screws. The patient woke with significant weakness in both lower limbs (muscle power 0/0) and voiding difficulty. Fortunately, he regained walking ability 4.5months later after intensive rehabilitation therapy.

Intraoperative administration of tramadol for postoperative nurse-controlled analgesia resulted in earlier awakening and less sedation than morphine in children after cardiac surgery.

In adults, intraoperative administration of tramadol could result in earlier recovery and less sedation than morphine. In this controlled, randomized, double-blind study, we investigated whether an intraoperative initial dose of tramadol could cause more rapid awakening from general anesthesia, less sedation, and earlier tracheal extubation than morphine in children during the immediate postoperative period. Forty children aged 1-6 yr, scheduled for atrial or ventricular septal defect repair and tracheal extubation in the pediatric intensive care unit, were randomly allocated to receive morphine, initial dose 0.2 mg/kg, or tramadol 2 mg/kg given at the end of sternal closure, followed by nurse-controlled analgesia (bolus 0.02 mg/kg of morphine and 0.2 mg/kg of tramadol) with background infusions (0.015 mg x kg(-1) x h(-1) for morphine and 0.15 mg x kg(-1) x h(-1) for tramadol). Postoperatively, children receiving tramadol had earlier awakening from general anesthesia (P = 0.02) and were less sedated at 1 and 2 h postoperatively (P = 0.03 and P = 0.01, respectively). Tracheal extubation was earlier in the tramadol group (P = 0.01). Lengths of pediatric intensive care unit stay did not differ between groups. Times to first trigger of nurse-controlled analgesia bolus and objective pain scores during the 48 h observation period were comparable between groups. The incidence of desaturation and emesis were similar between groups. The patients ate well and did not differ on Day 1 or Day 2.

Successful management of contrast medium extravasation injury through stellate ganglion block and intra-arterial nitroglycerin.

We describe the successful management of extravasation injury to the left hand by contrast medium with stellate ganglion block and intra-arterial nitroglycerin in a patient which befell during contrast-enhanced imaging. The incidence of contrast-medium extravasation injury is increasing because of the convenience and availability of contrast-enhanced imaging and ease of injection access. Extravasation of contrast medium may results in severe pain, erythema, cyanosis, and edema or even skin necrosis, which is largely related to the ionization, osmolarity, and volume of the contrast medium. The conservative treatment is often adequate in small amount extravasation, but if the extravasation is overwhelming further energetic management is mandatory. A 29-year-old man was brought to our emergency because of diffuse abdominal pain and he was arranged to receive intravenous contrast media enhanced abdominal computed tomography for diagnosis. Ruptured appendicitis with abscess formation was suspected; then the patient underwent emergent appendectomy and drainage of the abscess. However, severe swelling and cyanotic change that radiated from the intravenous catheter insertion site in every direction over the entire dorsum of the left hand were noted after the surgery. Contrast-medium extravasation injury was highly contemplated and a left stellate ganglion block was performed immediately for relief of symptoms. The consulting surgeon ruled out compartment syndrome, but advised emergent left upper limb arteriography, which revealed signs of vasospasm with high intravascular pressure of the left distal ulnar and radial arteries; thus nitroglycerin was injected into left distal ulnar and radial arteries for relief of vasospasm. The clinical symptoms were improved after the above managements and the patient was discharged 7 days later without any sequela.

Mechanical pain hypersensitivity after incisional surgery is enhanced in rats subjected to neonatal peripheral inflammation: effects of N-methyl-D-aspartate receptor antagonists.

BACKGROUND: Neonatal pain and inflammation may lead to a long-term effect on nociceptive processing in adults. The current study examined the characteristics of postoperative incisional pain behaviors in adult rats that were subjected to neonatal peripheral inflammation. METHODS: Rat pups received a subcutaneous injection of saline or carrageenan into the plantar surface of the left hind paw at postnatal day 1. Naive pups were used as the control. Paw withdrawal thresholds to punctuate mechanical stimuli were examined at postnatal days 35, 42, and 49. After rats received a plantar incision on the left or right hind paw at postnatal day 50, paw withdrawal thresholds were measured at 4 h, 1 day, 2 days, 3 days, 5 days, and 7 days after incision. In addition, spinal cord Fos expression was detected at 2 h after incision. Finally, the effects of intrathecal N-methyl-D-aspartate receptor antagonists DL-2-amino-5-phosphonovaleric acid and dizocilpine and the nitric oxide synthase inhibitor L-N-nitro-arginine methylester on incisional pain were examined at 4 h after incision. RESULTS: Although the rats subjected to neonatal peripheral carrageenan injection developed mechanical hypoalgesia in bilateral hind paws at baseline, they displayed increased spinal cord Fos expression at 2 h and exaggerated mechanical pain hypersensitivity at 4 h (but not at other time points) after plantar incision. Intrathecal DL-2-amino-5-phosphonovaleric acid, dizocilpine, and L-N-nitro-arginine methylester significantly attenuated incision-induced mechanical pain hypersensitivity at 4 h after incision in the neonatally carrageenan-treated rats, but not in the naive or neonatally saline-treated rats. CONCLUSIONS: The authors' results suggest that early inflammatory insults during the neonatal period could produce excessive incision-associated mechanical pain hypersensitivity in adult rats. Spinal cord N-methyl-D-aspartate receptors and downstream nitric oxide signaling might contribute to this abnormal pain hypersensitivity, although the mechanisms underlying the long-term effect of neonatal inflammation are still unclear.

Intrathecal ketorolac pretreatment reduced spinal cord ischemic injury in rats.

Paraplegia caused by spinal cord ischemic injury remains a potential complication of surgical repair of thoracoabdominal aortic aneurysms. Studies suggest that cyclooxygenase (COX) contributes to ischemic neuronal damage and that COX inhibitors may reduce injury. In this study, we examined whether intrathecal pretreatment with ketorolac, a nonselective COX inhibitor, had a protective effect against ischemic spinal cord injury in rats. Rats were randomized to receive either intrathecal normal saline, ketorolac 30 microg, or ketorolac 60 microg (n = 6 rats per group) 1 h before spinal cord ischemia (intraaortic balloon occlusion combined with proximal arterial hypotension for 11 min). Another 6 rats served as the sham-operated controls. Ischemic injury was assessed by hindlimb motor function and by histopathological changes in the lumbar spinal cord at 24 h after the ischemic insult. The other 20 rats (n = 10 per group) were used in the second experiments to evaluate the safety of this drug. Survival of rats was recorded 28 days after reperfusion. Intrathecal pretreatment with 60 microg of ketorolac significantly reduced neuronal death and improved hindlimb motor function, and the long-term survival was similar to that in the control group. The results suggest that intrathecal ketorolac may be of therapeutic potential for preventing spinal cord ischemic injury during thoracoabdominal aortic surgery.