Doo Sik Kim

Thrombospondin-4 Contributes to Spinal Sensitization and Neuropathic Pain States

Neuropathic pain is a common cause of pain after nerve injury, but its molecular basis is poorly understood. In a post-gene chip microarray effort to identify new target genes contributing to neuropathic pain development, we report here the characterization of a novel neuropathic pain contributor, thrombospondin-4 (TSP4), using a neuropathic pain model of spinal nerve ligation injury. TSP4 is mainly expressed in astrocytes and significantly upregulated in the injury side of dorsal spinal cord that correlates with the development of neuropathic pain states. TSP4 blockade by intrathecal antibodies, antisense oligodeoxynucleotides, or inactivation of the TSP4 gene reverses or prevents behavioral hypersensitivities. Intrathecal injection of TSP4 protein into naive rats is sufficient to enhance the frequency of EPSCs in spinal dorsal horn neurons, suggesting an increased excitatory presynaptic input, and to cause similar behavioral hypersensitivities. Together, these findings support that injury-induced spinal TSP4 may contribute to spinal presynaptic hypersensitivity and neuropathic pain states. Development of TSP4 antagonists has the therapeutic potential for target-specific neuropathic pain management.

Predictors of difficult intubation defined by the intubation difficulty scale (IDS): predictive value of 7 airway assessment factors

Background The intubation difficulty scale (IDS) has been used as a validated difficulty score to define difficult intubation (DI). The purpose of this study is to identify airway assessment factors and total airway score (TAS) for predicting DI defined by the IDS. Methods There were 305 ASA physical status 1-2 patients, aged 19-70 years, who underwent elective surgery with endotracheal intubation. During the pre-anesthetic visit, we evaluated patients by 7 preoperative airway assessment factors, including the following: Mallampati classification, thyromental distance, head & neck movement, body mass index (BMI), buck teeth, inter-incisor gap, and upper lip bite test (ULBT). After endotracheal intubation, patients were divided into 2 groups based on their IDS score estimated with 7 variables: normal (IDS < 5) and DI (IDS ≥ 5) groups. The incidence of TAS (> 6) and high score of each airway assessment factor was compared in two groups: odds ratio, confidence interval (CI) of 95%, with a significant P value ≤ 0.05. Results The odds ratio of TAS (> 6), ULBT (class III), head & neck movement (< 90°), inter-incisor gap (< 4 cm), BMI (≥ 25 kg/m2) and Mallampati classification (≥ class III) were respectively 13.57 (95% CI = 2.99-61.54, P < 0.05), 12.48 (95% CI = 2.50-62.21, P < 0.05), 3.11 (95% CI = 0.87-11.13), 2.32 (95% CI = 0.75-7.19), 2.22 (95% CI = 0.81-6.06), and 1.22 (95% CI = 0.38-3.89). Conclusions We suggest that TAS (> 6) and ULBT (class III) are the most useful factors predicting DI.

The cardiovascular effects of midazolam co-induction to propofol for induction in aged patients.

Background The aim of this study was to investigate whether a small dose of midazolam and lessening the propofol dosage could prevent cardiovascular change at tracheal intubation for induction in aged patients. Methods Eighty patients over 65 years (ASA physical status 1, 2) scheduled for elective surgery received general anesthesia with remifentanil and propofol or midazolam. Patients in group P (n = 40) were induced with 0.9% NaCl 0.03 ml/kg, propofol 1. 2 mg/kg and remifentanil. Patients in group MP (n = 40) were induced with midazolam 0.03 mg/kg, propofol 0.8 mg/kg and remifentanil. The time taken to reach loss of consciousness (LOC) and the value of bispectral index score (BIS) at LOC were recorded. After LOC, 0.8 mg/kg of rocuronium was given and tracheal intubation was performed. The mean blood pressure (MBP) and heart rate (HR) were recorded before induction as the base value, before intubation, immediately post-intubation and 3 minutes after intubation. Results Compared with the base values, MBP at before intubation and 3 minutes after intubation was significantly decreased in group P and group MP (P < 0.05). Compared with group P, the decrease of MBP was significantly less at before intubation, immediately after intubation and 3 minutes after intubation in group MP (P < 0.05). The time taken to reach LOC was significantly decreased in group MP compared with that in group P (P < 0.05). There were no significant differences of HR at any time between the two groups. Conclusions Co-induction with midazolam and propofol could prevent a marked BP decrease at tracheal intubation for induction in aged patients.

Cerebral air embolism after removal of internal jugular venous catheter - A case report -

Air embolism can occur during central venous catheter removal. We encountered a patient diagnosed with cerebral air embolism associated with the removal of an internal jugular venous catheter. The patient was 65 years old and was admitted to the intensive care unit due to pneumonia. He had a catheter placed in the right internal jugular vein. Five days thereafter, the catheter was removed in semi-Fowlers position using the Valsalva maneuver. Immediately after the catheter removal, the patient became pale, felt dyspneic, lost consciousness and exhibited seizure activity. A neurological examination, revealed left upper arm (grade I) and lower leg paralysis (grade II) as well as left facial palsy. A brain computed tomogram showed that, air was trapped in the cavernous sinus. In diffusion weighted magnetic resonance imaging, signal changes were reported in the right frontal cortex, indicating acute cerebral infarction. Hyperbaric oxygen therapy and ventilatory support with synchronized intermittent mandatory ventilation mode was applied. Twenty days thereafter, consciousness and motor functions were recovered completely except for mild weakness of the upper arm (grade IV).

Effect of Trendelenburg position on right and left internal jugular vein cross-sectional area

Background Unlike the right internal jugular vein (RIJV), there is a paucity of data regarding the effect of the Trendelenburg position on the left internal jugular vein (LIJV). The purpose of this study is to investigate the cross-sectional area (CSA) of the LIJV and RIJV and their response to the Trendelenburg position using two-dimensional ultrasound in adult subjects. Methods This study enrolled fifty-eight patients with American Society of Anesthesiologists physical status class I-II who were undergoing general anesthesia. CSAs of both the RIJV and LIJV were measured with a two-dimensional ultrasound in the supine position and then in a 10° Trendelenburg position. Results In the supine position, the transverse diameter, anteroposterior diameter, and CSA of the RIJV were significantly larger than those of the LIJV (P < 0.001). Of 58 patients, the RIJV CSA was larger than the LIJV CSA in 43 patients (74.1%), and the LIJV CSA was larger than the RIJV CSA in 15 patients (25.9%). In the Trendelenburg position, CSAs of the RIJV and LIJV increased 39.4 and 25.5%, respectively, compared with the supine position. However, RIJV changed at a rate that was significantly greater than that of the LIJV (P < 0.05). Of 58 patients, the RIJV CSA was larger than the LIJV CSA in 48 patients (82.8%), and the LIJV CSA was larger than the RIJV CSA in 10 patients (17.2%). Conclusions In supine position, the RIJV CSA was larger than the LIJV CSA. The increased CSA in the Trendelenburg position was greater in the RIJV than the LIJV.

Dexmedetomidine to Help Nerve Regeneration in a Rat Sciatic Nerve Injury Model

Background Several studies have shown that dexmedetomidine (DXM), a selective α2-adrenoceptor agonist, also has neuroprotective effects. However, its effect on impaired peripheral nerve regeneration has not been studied. Materials and Methods Forty-five Sprague-Dawley rats were randomly assigned to three groups: group 1 (control SHAM), group 2 (sciatic nerve injury + normal saline), and group 3 (sciatic nerve injury + DXM). The rats of group 3 were subdivided into the following three groups: DXM 0.5, 6, and 20 μg·kg−1 (groups 3A, 3B, and 3C, resp.). The sciatic nerve injury was assessed for nerve regeneration at 2 and 6 weeks. Results There were no differences between groups 2 and 3 in their sciatic functional index (SFI) values or histological findings at 2 weeks postinjury. However, SFI differences were statistically significant at 6 weeks postinjury in group 3. The gross findings with H&E staining showed that the number of axons was higher in group 3 than in group 2. There was no histological difference according to the DXM concentration. Conclusion The coincidental functional and histological assessment results of this study suggest that DXM for 6 weeks positively affects damaged peripheral nerves.

Paradoxical carbon dioxide embolism during laparoscopic cholecystectomy as a cause of cardiac arrest and neurologic sequelae: a case report

An 81-year-old male patient was scheduled for a laparoscopic cholecystectomy due to acute cholecystitis. About 50 minutes into the operation, the arterial blood pressure suddenly decreased and ventricular fibrillation appeared on the electrocardiography. The patient received cardiopulmonary resuscitation and recovered a normal vital sign. We suspected a carbon dioxide embolism as the middle hepatic vein had been injured during the surgery. We performed a transesophageal echocardiography and were able to confirm the presence of multiple gas bubbles in all of the cardiac chambers. After the operation, the patient presented a stable hemodynamic state, but showed weaknesses in the left arm and leg. There were no acute lesions except for a chronic cerebral cortical atrophy and chronic microvascular encephalopathy on the postoperative brain-computed tomography, 3D angiography and magnetic resonance image. Fortunately, three days after the operation, the patients hemiparesis had entirely subsided and he was discharged without any neurologic sequelae.

Difference of the hemodynamic changes induced by tracheal intubation using remifentanil between smokers and nonsmokers

Background It was well-known that smoking affects the cardiovascular system, and remifentanil can suppress the sympathetic stimulations induced by tracheal intubation. The purpose of this study was to investigate whether there was any difference in the hemodynamic changes induced by tracheal intubation with using remifentanil between smokers and nonsmokers. Methods Eighty patients were enrolled: male smokers (MS), male nonsmokers (MN), female smokers (FS) and female nonsmokers (FN). Anesthesia was induced with diluted remifentanil (20 µg/ml) at a rate of 10 µg/kg/hr using an infusion pump, and 2 min later, midazolam 0.05 mg/kg and propofol 0.8 mg/kg were injected for achieving unconsciousness. Rocuronium 1 mg/kg was used for muscle relaxation, and tracheal intubation was performed 2 min after rocuronium injection. After tracheal intubation, the remifentanil was decreased to 2 µg/kg/hr. The mean arterial pressure (MAP) and heart rate (HR) were checked before induction, on unconsciousness, just before intubation, just after intubation and 1, 2 and 3 minutes after intubation, and these values were compared between the groups. Results In men, the MAP and HR just after intubation and at 1, 2 and 3 minutes after intubation in Group MS were significantly higher than those of Group MN (P < 0.05). For the women, the HR in both groups (the FS and FN groups) were increased just after intubation and 1, 2 and 3 minutes after intubation compared with that at the baseline, respectively, but there was no difference between the two groups. Conclusions There was a difference of the hemodynamic changes induced by tracheal intubation with using remifentanil between the male smokers and nonsmokers, but not in women.