Difficult airway management of a patient with limited range of motion in the temporomandibular joint and cervical extension caused by psoriatic arthritis: a case report.

BACKGROUND: Psoriasis vulgaris, a chronic inflammatory skin disease, rarely causes temporomandibular arthritis. We report a case of difficult airway management of a patient with limited range of motion in the temporomandibular joint and cervical extension caused by psoriatic arthritis. CASE PRESENTATION: A 33-year-old man was scheduled to undergo laparoscopic colectomy. On admission, he was diagnosed with psoriatic arthritis. After induction of general anesthesia, we attempted intubation using Pentax Airway Scope® with a thin intlock blade and using a bronchoscope, but it was impossible because of the limited oral space and mandibular elevation. Because of concerns about cannot intubate, cannot ventilate, we antagonized the neuromuscular block and he emerged from general anesthesia. Finally, we succeeded in awake intubation via the nasal cavity using a bronchoscope under spontaneous respiration. CONCLUSIONS: Although psoriasis vulgaris is very rarely associated with temporomandibular arthritis, anesthesiologists should consider that it can cause perioperative difficult airways.

Dexmedetomidine Maintains Its Direct Cardioprotective Effect Against Ischemia/Reperfusion Injury in Hypertensive Hypertrophied Myocardium.

BACKGROUND: Dexmedetomidine (DEX) has a direct cardioprotective effect against ischemia/reperfusion injury through endothelial nitric oxide synthase (eNOS) phosphorylation via α2-adrenoreceptor (α2-AR). By using spontaneously hypertensive rat (SHR) and Wistar-Kyoto (WKY) rat models, the cardioprotective effect of DEX in hypertrophied myocardium and the differential characteristics of cardiac α2-AR and the I1 imidazoline receptor (I1R) were examined. METHODS: Langendorff-perfused rat hearts underwent 40 minutes of global ischemia followed by 120 minutes of reperfusion in the presence or absence of DEX before ischemia. Infarct size was measured, and eNOS phosphorylation was assessed by Western blotting. The presence and expression of the receptors were assessed by immunohistochemistry, real-time reverse transcriptase polymerase chain reaction, and Western blotting. RESULTS: In WKY, DEX significantly decreased infarct size and increased phosphorylated-eNOS/eNOS. These effects were counteracted by yohimbine (α2-AR antagonist) and efaroxan (α2-AR and I1R antagonist). In SHR, DEX significantly decreased infarct size, and the effect was counteracted by efaroxan but not yohimbine. DEX did not alter phosphorylated-eNOS/eNOS in SHR. α2-AR and I1R were observed in WKY and SHR hearts. Although alpha2A-AR and alpha2B-AR messenger RNA and protein levels were upregulated in SHR, I1R expression was comparable between the 2 species. CONCLUSIONS: In the hypertrophied heart, DEX maintains its direct cardioprotective effect against ischemia/reperfusion injury via I1R in an eNOS-nondependent manner despite upregulation of α2-AR.

Nitrite administration improves sepsis-induced myocardial and mitochondrial dysfunction by modulating stress signal responses.

PURPOSE: A specific therapeutic strategy in sepsis-induced myocardial dysfunction remains to be determined. Nitrite may have cardioprotective effects against sepsis-induced myocardial dysfunction. This study investigated the cardioprotective effects of nitrite on myocardial function, mitochondrial bioenergetics, and its underlying molecular mechanisms in severe septic rats. METHODS: Sepsis was induced in male Wistar rats by cecal ligation and puncture (CLP). After CLP, we administered normal saline (NS group) or nitrite (nitrite group) subcutaneously. We administered nitrite at different doses (0.1-10 mg/kg) to ascertain the most effective dose and examined cardiac function in an isolated heart experiment 8 h after CLP. We investigated mitochondrial bioenergetics and molecular mechanisms underlying the administration of nitrite in vitro. RESULTS: In isolated heart experiments, the left ventricular developed pressure (96 ± 5 mmHg) at a moderate nitrite dose (1.0 mg/kg) was significantly higher than that in the NS group (75 ± 4 mmHg, P < 0.05). Mitochondrial oxidative phosphorylation in the nitrite group was significantly higher than that in the NS group (P < 0.01). Immunoblotting revealed that nitrite significantly increased the phosphorylation of Akt (P < 0.05) and reduced the nuclear translocation of NF-κB (P < 0.05) compared with the NS group. Nitrite was also shown to improve the rate of survival in severe septic rats (P < 0.001). CONCLUSIONS: Our results showed that a moderate nitrite dose improved septic myocardial dysfunction at organ, cellular, and molecular levels via modulation of stress signal responses, which resulted in an improvement in survival.

Nitrite Reduces Ischemia-Induced Ventricular Arrhythmias by Attenuating Connexin 43 Dephosphorylation in Rats.

BACKGROUND: Ventricular arrhythmias induced by ischemic heart disease are the main cause of sudden cardiac death. Ischemia can cause life-threatening arrhythmias by modulating connexin 43 (Cx43), a principal cardiac gap junction channel protein. The present study investigates whether nitrite can attenuate ischemia-induced ventricular arrhythmias and dephosphorylation of Cx43 in a rat model. METHODS: Rats were medicated with normal saline (control, n = 10), nitrite (0.015, 0.15, and 1.5 mg/kg, n = 9 or 10 each), and 0.15 mg/kg nitrite with either the nitric oxide scavenger 2-(4-carboxyphenyl)-4, 4, 5, 5-tetramethylimidazoline-1-oxyl-3-oxide, sodium salt (cPTIO; n = 9) or allopurinol (xanthine oxidoreductase inhibitor, n = 9). We determined the severity of ventricular arrhythmias based on arrhythmia scores and levels of phosphorylated Cx43. RESULTS: The median arrhythmia score may have been lower in the group given 0.15 mg/kg nitrite (4 [interquartile range {IQR}, 4-5]) than that in the control group (7.5 [IQR, 5.25-8]; P = 0.013). There was no difference among the control, the given 0.015 mg/kg nitrite (7 [IQR, 5-8]), and 1.5 mg/kg nitrite (7 [IQR, 5.5-7.75]; P = 0.95). The arrhythmia scores in the cPTIO (6 [IQR, 5-8]; P = 0.030) and allopurinol (7 [IQR, 5-8]; P = 0.005) groups may have been higher than that in 0.15 mg/kg nitrite group. Immunoblotting revealed that the level of phosphorylated Cx43 in the group given 0.15 mg/kg nitrite, but not in the other treated groups, was significantly higher compared with the control group (P = 0.007). CONCLUSIONS: Nitrite may have attenuated acute ischemia-induced ventricular arrhythmias and Cx43 dephosphorylation in rats. Nitric oxide, which might be generated by xanthine oxidoreductase via nitrite reduction, appears to play a crucial role in this antiarrhythmic effect.

Substrate-dependent modulation of oxidative phosphorylation in isolated mitochondria following in vitro hypoxia and reoxygenation injury.

BACKGROUND/OBJECTIVES: Previous studies using isolated mitochondria have provided new insight into the mechanisms and interventions for ischemia and reperfusion (I/R) injury. In in vitro experiments involving isolated mitochondria, hypoxia and reoxygenation (H/R) has been widely used to mimic I/R injury. However, in in vitro H/R mitochondrial experiments, the effects of various substrates on mitochondrial oxidative phosphorylation are unclear. In the present study, the effects of in vitro I/R injury on mitochondrial oxidative phosphorylation under different substrate conditions were investigated. METHODS: Hypoxia was achieved following complete consumption of oxygen by mitochondria isolated from rat heart tissue in an experimental chamber. The H/R protocol involved 30 min hypoxia followed by 15 min reoxygenation in a chamber opened to the atmosphere. Mitochondrial respiration and respiratory control ratio (RCR) were measured. RESULTS: When pyruvate/malate were used as substrates, H/R significantly decreased state 3 respiration (28.2±12 nmol O2/min/mg protein) and RCR (2.7±0.8) compared with the control (121.4±32.5 nmol O2/mg protein/min and 7.8±1.2, respectively). In contrast, when succinate was used without rotenone, H/R significantly increased state 3 respiration (57.0±11.2 nmol O2/mg protein/min) and RCR (2.0±0.3) compared with the control (48.2±12.3 nmol O2/mg protein/min and 1.3±0.2, respectively). CONCLUSIONS: The present study demonstrated that mitochondrial oxidative phosphorylation can be modulated by H/R in vitro depending on substrate conditions.

Heart rate variability during abdominal surgical manipulation under general and epidural anesthesia.

Anesthesiologists occasionally encounter bradycardia during abdominal surgery and recognize the phenomenon as a vagal reflex. The presence of bradycardia implies efferent vagal dominance in the autonomic nervous system during this vagal reflex. In this study, we investigated the effect of abdominal surgical manipulation on autonomic nervous activity, using heart rate variability analysis. Abdominal surgical manipulation decreased the heart rate and enhanced not only the high-frequency power (0.15-0.4 Hz) but also the low-frequency power (0.04-0.15 Hz) calculated from the power spectral density of heart rate variability. Our results suggest that both vagal tone and sympathetic tone could be activated during the vagal reflex caused by abdominal surgical manipulation.

Ultrasound-aided ipsilateral-dominant epidural block for total hip arthroplasty: a randomised controlled single-blind study.

BACKGROUND AND OBJECTIVE: Lumbar epidural anaesthesia usually affects both legs. The aim was to compare the success rates of ultrasound-aided vs. classical midline epidural catheter insertion for ipsilateral-dominant blocks and analgesia in patients undergoing total hip arthroplasty. METHODS: The protocol was designed as a prospective randomised single-blind study. In the ultrasound group (n = 12), ultrasound examination was performed to determine the puncture point and direction for ipsilateral-dominant block. In the midline group (n = 12), epidural puncture was performed by the usual midline approach. Rates of successful ipsilateral-dominant block using 6 ml of lidocaine 1.5% wt vol⁻¹ (primary outcome) and effects of patient-controlled epidural analgesia using ropivacaine 0.2% wt vol⁻¹ (secondary outcomes) were evaluated. RESULTS: The rates of successful ipsilateral-dominant block were 83% in the ultrasound group and 17% in the midline group (P = 0.004). Sensory and motor functions on the non-operated side in the ultrasound group were significantly better maintained than those on the operated side and compared with those on the non-operated side in the midline group (P < 0.05). Pain scores at mobilisation, incidence of post-operative nausea and vomiting and frequency of use of supplemental analgesics were significantly lower in the ultrasound group than in the midline group (P < 0.05). CONCLUSION: The use of ultrasound significantly improves the success rate of ipsilateral epidural block compared with the standard midline approach.

Ultrasound-aided unilateral epidural block for single lower-extremity pain.

We report an ultrasound-aided unilateral epidural block, employed in two patients, to provide better analgesia and motor function for lower-extremity pain. The patient in case 1 was a 72-year-old woman who suffered pain arising from Herpes zoster rash on the left leg (the second lumbar nerve area). A left-dominant continuous unilateral epidural block was performed to reduce her pain. After confirming the L2/3 epidural space and needle direction using ultrasound imaging, epidural cannulation was performed. Continuous infusion of 4 ml h(-1) of 1% lidocaine through the epidural catheter eliminated the herpetic pain in the left leg, maintaining motor function and normal sensation in her right leg. The patient in case 2 was a 35-year-old man whose complaint was postoperative pain in his left knee during passive movement. Dependent-side (left-side) dominant ultrasound-aided continuous unilateral epidural block, the same procedure as that used in case 1, was performed at the L3/4 intervertebral space. His left knee pain was clearly reduced, with partial paralysis, but motor function in his right leg was completely normal during the continuous epidural block with 4 ml h(-1) of 0.2% ropivacaine. Ultrasound imaging around the epidural space facilitated effective unilateral epidural block for single lower-extremity pain in both patients. This technique could decrease possible side effects and improve patient satisfaction during continuous nerve block by maintaining motor function and sensation in the nondependent side.

[Two cases of epidural anesthesia using ultrasound imaging].

We report two cases of epidural anesthesia in an 11-year-old obese girl (BMI 34.5) using ultrasound imaging by an inexperienced resident. It was useful for performing epidural anesthesia in these difficult cases to observe anatomical structure around epidural space and to measure the angle and distance from the skin to the epidural space. The distances in ultrasound imaging and actual puncture in case 1 were 171 mm and 250 mm, and in case 2 these were 439 mm and 480 mm, respectively. In both cases, epidural puncture was performed smoothly at the first attempt and there was no adverse effect. We conclude that using ultrasound imaging before epidural puncture in obese children is safer and more educational for residents.