Acute massive pulmonary embolism treated by urgent pulmonary embolectomy: A case report.

The management of acute massive pulmonary embolism presents a clinical challenge as currently there is no consensus for definitive treatment. Early decision-making regarding surgical intervention is essential when the risk of mortality is high.

Intraoperative diagnosis of an unsuspected ruptured left ventricular aneurysm using transesophageal echocardiography: A case report.

Transesophageal echocardiography (TEE) enables a more accurate visualization of left ventricular posterior aneurysms than transthoracic echocardiography due to the close proximity of the esophagus to the posterior ventricular wall. Therefore, TEE is essential for the accurate diagnosis of posterior aneurysm, particularly in urgent settings where preoperative assessments may be insufficient.

Effect of carbamazepine and gabapentin on excitability in the trigeminal subnucleus caudalis of neonatal rats using a voltage-sensitive dye imaging technique.

BACKGROUND: The antiepileptic drugs carbamazepine and gabapentin are effective in treating neuropathic pain and trigeminal neuralgia. In the present study, to analyze the effects of carbamazepine and gabapentin on neuronal excitation in the spinal trigeminal subnucleus caudalis (Sp5c) in the medulla oblongata, we recorded temporal changes in nociceptive afferent activity in the Sp5c of trigeminal nerve-attached brainstem slices of neonatal rats using a voltage-sensitive dye imaging technique. RESULTS: Electrical stimulation of the trigeminal nerve rootlet evoked changes in the fluorescence intensity of dye in the Sp5c. The optical signals were composed of two phases, a fast component with a sharp peak followed by a long-lasting component with a period of more than 500 ms. This evoked excitation was not influenced by administration of carbamazepine (10, 100 and 1,000 µM) or gabapentin (1 and 10 µM), but was increased by administration of 100 µM gabapentin. This evoked excitation was increased further in low Mg(2+) (0.8 mM) conditions, and this effect of low Mg(2+) concentration was antagonized by 30 µM DL-2-amino-5-phosphonopentanoic acid (AP5), a N-methyl-D-aspartate (NMDA) receptor blocker. The increased excitation in low Mg(2+) conditions was also antagonized by carbamazepine (1,000 µM) and gabapentin (100 µM). CONCLUSION: Carbamazepine and gabapentin did not decrease electrically evoked excitation in the Sp5c in control conditions. Further excitation in low Mg(2+) conditions was antagonized by the NMDA receptor blocker AP5. Carbamazepine and gabapentin had similar effects to AP5 on evoked excitation in the Sp5c in low Mg(2+) conditions. Thus, we concluded that carbamazepine and gabapentin may act by blocking NMDA receptors in the Sp5c, which contributes to its anti-hypersensitivity in neuropathic pain.

Orexin-B antagonized respiratory depression induced by sevoflurane, propofol, and remifentanil in isolated brainstem-spinal cords of neonatal rats.

Orexins (hypocretins) play a crucial role in arousal, feeding, and endocrine function. We previously reported that orexin-B activated respiratory neurons in the isolated brainstem-spinal cords of neonatal rats. We herein determined whether orexin-B antagonized respiratory depression induced by sevoflurane, propofol, or remifentanil. We recorded C4 nerve bursts as an index of inspiratory activity in a brainstem-spinal cord preparation. The preparation was superfused with a solution equilibrated with 3% sevoflurane alone for 10 min and the superfusate was then switched to a solution containing sevoflurane plus orexin-B. Sevoflurane decreased the C4 burst rate and the integrated C4 amplitude. The C4 burst rate and amplitude were reversed by 0.5 µM orexin-B, but not by 0.1 µM orexin-B. The decrease induced in the C4 burst rate by 10 µM propofol or 0.01 µM remifentanil was significantly antagonized by 0.1 µM orexin-B. Respiratory depression induced by a higher concentration (0.1 µM) of remifentanil was not restored by 0.1 µM orexin-B. These results demonstrated that orexin-B antagonized respiratory depression induced by sevoflurane, propofol, or remifentanil.

Effect of carbamazepine and gabapentin on excitability in the trigeminal subnucleus caudalis of neonatal rats using a voltage-sensitive dye imaging technique

BACKGROUND: The antiepileptic drugs carbamazepine and gabapentin are effective in treating neuropathic pain and trigeminal neuralgia. In the present study, to analyze the effects of carbamazepine and gabapentin on neuronal excitation in the spinal trigeminal subnucleus caudalis (Sp5c) in the medulla oblongata, we recorded temporal changes in nociceptive afferent activity in the Sp5c of trigeminal nerve-attached brainstem slices of neonatal rats using a voltage-sensitive dye imaging technique. RESULTS: Electrical stimulation of the trigeminal nerve rootlet evoked changes in the fluorescence intensity of dye in the Sp5c. The optical signals were composed of two phases, a fast component with a sharp peak followed by a long-lasting component with a period of more than 500 ms. This evoked excitation was not influenced by administration of carbamazepine (10, 100 and 1,000 µM) or gabapentin (1 and 10 µM), but was increased by administration of 100 µM gabapentin. This evoked excitation was increased further in low Mg²+ (0.8 mM) conditions, and this effect of low Mg²+ concentration was antagonized by 30 µM DL-2-amino-5-phosphonopentanoic acid (AP5), a N-methyl-D-as-partate (NMDA) receptor blocker. The increased excitation in low Mg²+ conditions was also antagonized by carbamazepine (1,000 µM) and gabapentin (100 µM). CONCLUSION: Carbamazepine and gabapentin did not decrease electrically evoked excitation in the Sp5c in control conditions. Further excitation in low Mg²+ conditions was antagonized by the NMDA receptor blocker AP5. Carbamazepine and gabapentin had similar effects to AP5 on evoked excitation in the Sp5c in low Mg²+ conditions. Thus, we concluded that carbamazepine and gabapentin may act by blocking NMDA receptors in the Sp5c, which contributes to its anti-hypersensitivity in neuropathic pain.

Orexin induces excitation of respiratory neuronal network in isolated brainstem spinal cord of neonatal rat.

Endogenous neuropeptides known as orexins (hypocretins) play important roles in the regulation of feeding, drinking, endocrine function, and sleep/wakefulness. Orexin neuron projection sites include the rostral ventrolateral medulla of brainstem, which is related to the control of breathing. Previous studies suggest that orexins modulate the central CO2 ventilatory response during wakefulness in rodent. In the present study, we examined the effects of the orexinergic system on central respiratory control by adding orexin into a superfusion medium in the isolated brainstem-spinal cord of neonatal rat. Exposure to orexin B resulted in dose-dependent increases in C4 burst rate via brainstem, but not spinal cord. These increases in C4 burst rate induced concomitant increases in the depolarizing cycle rate of pre-inspiratory (Pre-I) and inspiratory (Insp) neurons. Tonic discharge was induced on C4 recording, although the rhythmic bursts of Pre-I and Insp neurons were maintained. Expiratory (Exp) neurons were also depolarized on administration of orexin B. Our findings indicate that orexin B activates central respiratory activity, mainly through depolarization and decreases in membrane resistance in Pre-I and Insp neurons, and possibly through early initiation of the expiratory phase induced by depolarization of Exp neurons.

Sevoflurane in combination with propofol, not thiopental, induces a more robust neuroapoptosis than sevoflurane alone in the neonatal mouse brain.

PURPOSE: Sevoflurane is the most widely used volatile anesthetic of general anesthesia. In children and neonates, it is commonly used alone or in combination with thiopental or propofol. A few recent studies reported that sevoflurane induced neuronal death in the developing rodent brain. We measured the neurotoxicity of these anesthetics at clinical doses, alone and in combination, in the developing mouse brain. METHODS: Seven-day-old C57BL/6 mice were randomly assigned to 6 treatment groups. Three groups were exposed to 3% sevoflurane for 6 h after injection of saline, thiopental (5 mg/kg), or propofol (10 mg/kg), whereas three groups were exposed to room air for 6 h after injection of equal doses of saline, thiopental, or propofol. Apoptosis in the hippocampal CA1 region (CA1) and retrosplenial cortex (RC) was assessed using caspase-3 immunostaining. RESULTS: Sevoflurane alone caused significantly higher apoptosis in the CA1 compared with saline plus air (P = 0.04). Sevoflurane in combination with propofol resulted in significantly greater numbers of apoptotic neurons than sevoflurane alone in both the CA1 and the RC (P = 0.04). However, there was no significant difference in apoptotic neuron density in both the regions between the groups treated with sevoflurane alone and in combination with thiopental (P = 0.683). CONCLUSION: Sevoflurane alone can induce neuronal apoptosis, and this effect is enhanced by propofol. Thiopental did not exacerbate the neurotoxicity of sevoflurane. There is the possibility that the combination of sevoflurane and propofol is a more harmful anesthetic technique than sevoflurane alone in pediatric patients.

Upper airway obstruction associated with flexed cervical position after posterior occipitocervical fusion.

Upper airway obstruction resulting from overflexion fixation of the cervical spine is a rare but life-threatening complication after cervical spine surgery. There are few reports of dyspnea after a posterior cervical fusion. We present the case of a 63-year-old woman with rheumatoid arthritis who developed an upper airway obstruction immediately after an O-C4 fusion. She was reintubated with a fiberoptic scope. Revision surgery allowing the angle to return to the neutral position was performed to ameliorate the overflexion of the cervical spine fixation and the consequent upper airway obstruction. After revision surgery, the upper airway obstruction disappeared. Our experience suggests that intraoperative use of fluoroscopy and extubation with a tube exchanger are recommended to avoid this complication, especially in patients at high risk of upper airway obstruction.

Application of gum elastic bougie to nasal intubation.

Gum elastic bougie (GEB), a useful device for difficult airway management, has seldom been used for nasotracheal intubation. Among 632 patients undergoing dental procedures or oral surgery, GEB was used successfully in 16 patients in whom conventional nasal intubation had failed because of anatomical problems or maldirection of the tip of the tracheal tube. We recommend that GEB should be applied from the first attempt for nasal intubation in patients with difficult airways.

Comparison of tracheal diameter measured by chest x-ray and by computed tomography.

Assessments of tracheal diameter (TD) are important to select proper endotracheal tubes. Previous studies have used X-ray and physical indices to estimate tracheal diameter but these may not reflect the actual TD. We compared TD measured by X-ray (TD-XP) and by computer tomography (TD-CT) in 200 patients. Also, we analyzed correlation of TD-CT with physical indices such as age, height, weight, and BMI. TD-XP and TD-CT were significantly correlated (male: n = 55, P = .0146; female: n = 91, P = .001). TD-XP was 0.4 mm wider in male and 1.0 mm wider in female than TD-CT. However, correlation coefficients of TD-XP and TD-CT are very weak (male: r = 0.36; female: r = 0.653). TD-CT did not correlate with age, height, weight, or BMI. Our findings suggest that correlations of TD-XP and TD are statistically significant but not clinically significant. Physical indices are not useful to estimate TD.

Laudanosine has no effects on respiratory activity but induces non-respiratory excitement activity in isolated brainstem-spinal cord preparation of neonatal rats.

Laudanosine, a degradation of neuomuscular blocking agent atracurium, crosses the blood-brain barrier and is indicted to trigger seizures at high concentration. In Xenopus Oocytes expressing nicotinic acetylcholine receptors (nAChRs), laudanosine has activating and inhibiting effects on nAChRs depending on its concentration. nAChRs is related to respiratory activities and thus, in the present study, we analyzed effects of laudanosine on central respiratory activities using isolated brainstem-spinal cord preparation of neonatal rats. The rhythmic inspiratory burst activity of the C4 spinal ventral root was recorded using a glass suction electrode as an index of respiratory rate. After superfusion with mock cerebrospinal fluid (CSF), the preparation was superfused with mock CSF containing laudanosine 1, 10 or 100 microM for 60 minutes. Laudanosine 1, 10 and 100 microM (n = 10 in each) did not induce any effects on C4 respiratory rate. In all 10 preparations, laudnosine 100 microM induced non-respiratory excitement activities that are possibly same as seizure observed in vivo study.

Anesthetic management of a neonate with type IV laryngotracheo-esophageal cleft.

Laryngotracheo-esophageal cleft is a rare congenital anomaly that occurs when the trachea and esophagus fail to separate during fetal development. Clinical severity varies greatly in anatomic cleft extent. We report the successful management of the airway of a neonate with type IV laryngotracheo-esophageal cleft for the gastric division surgery by dividing the esophagogastric continuity between the esophageal orifice and the stomach using the balloon catheter and remaining spontaneous breathing through the large cuffed tracheal tube inserted into the esophageal orifice.

Effects of wearing complete dentures during sleep on the apnea-hypopnea index.

PURPOSE: The aim of this study was to investigate whether wearing complete dentures during sleep can improve the apnea-hypopnea index (AHI). MATERIALS AND METHODS: A total of 34 edentulous patients (16 men and 18 women, mean age: 72.5 +/- 8.8 years) completed the study. Portable sleep recording was performed for two nights in patients' homes. All patients wore complete dentures one night and slept without dentures the other night. Information about medical history and denture use was obtained for all patients. The occurrence of obstructive sleep apnea syndrome (OSAS) was calculated in edentulous patients, and the effect that wearing complete dentures during sleep had on the AHI was evaluated. RESULTS: Twenty-seven of the 34 patients suffered from OSAS with an AHI > or = 5. The mean AHI in patients sleeping with dentures was lower than that of those without dentures (13.3 +/- 10.0 versus 17.7 +/- 14.6, P= .022). Nineteen of these 27 patients showed a decrease in AHI while eight showed an AHI increase, of whom four showed increases of more than 5 points when wearing dentures during sleep. CONCLUSIONS: Wearing complete dentures during sleep improves the AHI of most edentulous OSAS patients. In contrast, some patients suffer from AHI increases due to the use of complete dentures. Also in some patients, any significant change in AHI associated with the usage of complete dentures went unnoticed. Thus, careful attention should be given when complete dentures are recommended for edentulous OSAS patients.