Is the Perfusion Index Useful in Early Detection of High Spinal Subarachnoid Block during Cesarean Section?

OBJECTIVE: To investigate the usefulness of the perfusion index (PI) in the early detection of high spinal subarachnoid block (SAB) for cesarean section (CS). METHOD: SAB was applied in patients of CS. The patients was subdivided into two groups, according to the highest level of block: the Ce group (cervical spine level) and the Th group (thoracic spine level). The PI values in the finger and toe, and vital signs were measured at pre- and post-SAB in both groups together with SAB level. RESULTS: The PI valuses in the finger and toe were elevated post-SAB in both groups; it showed no significant difference between them. However, in the Ce group, anesthesia immediately reached the upper thoracic nerves, and blood pressure showed a significant decrease post-SAB. CONCLUSIONS: Post-SAB finger PI value measuerments may not be useful for early detection of high SAB. Alternatively, the anesthesiologist should pay attention to immediate post-SAB changes in clinical signs such as a decrease in blood pressure as well as a rapid elevation of block level.

A Case of Mediastimal Emphysema Possibly Caused by the Insertion of a Laryngoscope.

Insertion of a laryngoscope to a patient with a strong pharyngeal reflex resulted in pharyngeal injury and subsequent development of mediastinal emphysema. An increase in airway pressure accompanying a strong pharyngeal reflex, as well as pharyngeal injury were thought to be factors associated with the development of mediastinal emphysema.

A Case of Superior Mesenteric Artery Occlusion Caused by Delayed Administration of Anticoagulants in a Patient with Nonvalvular Atrial Fibrillation.

A 86-year-old female with nonvalvular atrial fibrillation (NOVAF) who did not receive prophylactic anticoagulant treatment visited our hospital because of gastrointestinal symptoms. At first, acute gastroenteritis was suspected, but later she developed ileus and she was diagnosed with superior mesenteric artery occlusion (SMAO). We successfully performed the anesthetic management of this patient and subtotal resection of the small intestine was performed. Heparin was initiated after surgery, but she developed cerebral infarction later, and finally she died due to infection and anemia caused by melena. Although this patient was at high risk of thrombosis, she did not receive anticoagulant treatment. It might result in developing SMAO, and once SMAO occurred, thrombosis recurred even on anticoagulant treatment. This case suggested the importance of primary prevention of thrombosis in patients with NVAF.

Intraperitoneal residual contrast agent from hysterosalpingography detected following cesarean section.

Residual contrast agent from hysterosalpingography was detected in the abdominal cavity in a patient who had undergone Cesarean section. It is believed that magnetic resonance imaging alone would be sufficient to distinguish such medium from a foreign body in such cases.

Visibility of ultrasound-guided echogenic needle and its potential in clinical delivery of regional anesthesia.

OBJECTIVE: Ultrasound-guided regional anesthesia is recommended for nerve block due to its safety and reliability. Needle visualization is important when inserting needles into tissues in close proximity to target nerves. For safety reasons, the tip of the standard-type needle for application of nerve block is thinner than that of an interventional needle for insertion into intra-abdominal organs, and this makes it harder to determine its precise position. The purpose of this study was to evaluate the performance of an insulated echogenic needle under ultrasound guidance in phantoms and in the routine anesthetic management of patients undergoing elective surgery. METHODS: Needles with a 21-G diameter were inserted into Blue PhantomTM (Advanced Medical Technologies, LLC, WA) and chicken breast phantoms at angles of 15, 30, 45, 60, and 75 degrees relative to the surface. The needle was scanned by ultrasound using a TiTANTM (SonoSite, WA, USA). Visualization was compared between an insulated needle with corner cube reflectors (CCR-type: Hakko, Japan) and an insulated standard needle (S-type: Hakko, Japan). Both types of needle were also used to deliver regional anesthesia in patients with an ASA classification of PS1-2 undergoing elective surgery. RESULTS: The tip of CCR appeared as 3 bright points under ultrasound, and was more hyperechoic than S. The CCR-type needle was clearly visible under ultrasound at insertion angles of 15, 30, and 45 degrees, and was consistently more hyperechoic than S. However, at steeper angles of > 60 degrees, visibility was poorer. In delivering clinical regional nerve block, CCR was usually more hyperechoic than S, allowing the nerve block points targeted to be accessed with greater ease. CONCLUSIONS: The better visibility of the tip of CCR indicates that it is superior to S in the clinical delivery of peripheral nerve block.

Case of Wenckebach-type atrioventricular block caused by administration of indigo carmine.

We report a case of first-degree atrioventricular (A-V) block progressing to second-degree (Wenckebach-type) A-V block after administration of indigo carmine in a patient undergoing hysterectomy under general anesthesia. We believe that the onset of Wenckebach-type A-V block may have been induced by one or more of three factors: 1) preoperative first-degree A-V block, 2) the anesthetics used (propofol and remifentanil), and 3) administration of indigo carmine.

Subchronic administration of ketamine decreases the mRNA expression of serine racemase in rat brain.

The behavioral impairment produced by ketamine represents a pharmacological model for some aspects of schizophrenia such as positive, negative, and cognitive symptoms. Despite the multiple properties of ketamine, the main mechanism for its psychomimetic and anesthetic effect involves NMDA receptor system. Present study examined whether subchronic administration of ketamine at the subanesthetic doses (50 mg/kg) induces changes of behavior analogous to those observed in schizophrenia and the gene expressions of the enzymes for D-serine, an endogenous co-agonist for the NMDA-glycine site, in rat brain. Administration of ketamine daily for 14 consecutive days increased stereotyped behavior, ataxia and locomotion. The levels of serine racemase mRNAs in forebrain areas significantly decreased after subchronic administration of ketamine. In contrast, subchronic ketamine administration produced a significant increase in the mRNA expression of D-amino acid oxidase in the midbrain. These findings suggest that there is a relationship between the gene expression of the D-serine-related enzymes and the blockade of the NMDA receptors.

Ketamine enhances the expression of serine racemase and D-amino acid oxidase mRNAs in rat brain.

We have evaluated the effects of the acute administration of noncompetitive N-methyl-D-aspartate receptor antagonist, ketamine, on the expression of serine racemase and D-amino acid oxidase mRNAs in several brain areas of rats. The ketamine administration produced a dose-dependent and transient elevation in the levels of serine racemase and D-amino acid oxidase mRNAs in all the brain areas. These findings suggest that there is a relationship between the gene expression of the d-serine-related enzymes and the blockade of the N-methyl-D-aspartate receptors.

Optimal puncture site of the right internal jugular vein after laryngeal mask airway placement.

BACKGROUND: Puncturing of the internal jugular vein (IJV) after placement of a laryngeal mask airway (LMA) is difficult. Overlapping of the right internal jugular vein (IJV) and common carotid artery (CCA) after placement of an LMA-Classic (Laryngeal Mask Company, Henley-on-Thames, United Kingdom) was investigated using an ultrasound scanner. A study was conducted to determine the optimal puncture site in the case of puncturing the right IJV after LMA-Classic placement. METHODS: The subjects in this study consisted of 114 patients (60 men and 54 women) scheduled to undergo LMA-Classic placement (size 4 for men and size 3 for women). Overlapping between the IJV and CCA was investigated at three points (high, middle, and low points) on the right side of the neck after LMA-Classic placement. A test puncture was also made at the right low (supraclavicular) point after LMA-Classic placement. RESULTS: (1) The degree of overlapping of the right IJV and CCA after LMA-Classic placement was clearly greater than before LMA placement. (2) With the exception of some measurements, there were many cases in which the right IJV and CCA were completely overlapping after LMA-Classic placement. Furthermore, the CCA was not observed in the vicinity of the right IJV at the right low point. (3) There were no complications (including pneumothorax and accidental arterial puncture) during supraclavicular IJV puncture after LMA-Classic placement. CONCLUSION: After placement of the LMA-Classic, overlapping of the IJV and CCA increased at the high and middle puncture points of the IJV; however, at the lower puncture point, the position of the vessels remained unaffected. Therefore, during IJV puncture at high or middle points, ultrasound guidance is advisable to avoid CCA puncture.

Anesthetic management for repair of adult Bochdalek hernia by laparoscopic surgery.

This report describes anesthetic management of a case (a 64-year-old man) who was originally diagnosed as paraesophageal hernia before surgery and later diagnosed as Bochdalek hernia during laparoscopic surgery. Anesthesia was started with oxygen, nitrous oxide, and sevoflurane, and respiration was managed using controlled mechanical ventilation. Although left pneumothorax was noticed during laparoscopic surgery (aeroperitonia pressure: 10 cmH2O), the surgery was performed using the same anesthesia procedure, because hardly any changes were observed on the monitor and vital signs were stable. The surgery was completed without incident. However, postoperative chest X-rays revealed the residual large pneumothorax. A chest drain tube was inserted immediately, after which the pneumothorax was improved. Pneumothorax is considered to be inevitable in cases of laparoscopic repair of Bochdalek hernia. To prevent exacerbation of pneumothorax, anesthetic management should consist of discontinuing the use of nitrous oxide and lowering the aeroperitonia pressure concomitently with the use of positive airway pressure.

Straight advancement of epidural catheter--comparative assessments by method and site of epidural needle puncture and angle of puncture.

The catheter straight advancement rate for introduction into the epidural space was investigated using a radiopaque catheter. One hundred patients were divided into two groups and underwent thoracic or lumbar epidural punctures, with one of two different puncture methods: the median approach or paramedian approach. Two different angles of epidural puncture needle insertion, 50-60 degrees and 90 degrees to skin surface plane, were used. A catheter was inserted into the epidural space about 5 cm cephalad and the course of the inserted catheter was ascertained by radiography. The results have shown that punctures performed at an insertion angle of 50-60 degrees yielded higher catheter straight advancement rates than those performed at an angle of 90 degrees in both thoracic and lumbar epidural punctures.

The efficiency of beta 2-agonist delivery through tracheal tubes with the metered-dose inhaler: an in vitro study.

PURPOSE: To study the delivery efficiency of procaterol aerosols administered through the tracheal tube (ETT) with a metered-dose inhaler (MDI) during apnea. METHODS: First, in a normal room air environment (at ambient temperatures of 24 degrees to 26 degrees C), we measured the amount of aerosol delivered through the ETT by comparing the weight of a 2-l bottle before and after firing the MDI directly into the 15-mm adapter of the ETT. The distal half of the ETT was inserted in the bottle. This procedure was repeated using five different ETTs with an internal diameter of 4-8.5 mm. The delivery efficiency was obtained by dividing the amount of aerosol delivered through the ETT by the total aerosol output per MDI puff. Next, we investigated whether the connector attached to the 15-mm ETT adapter could reduce the delivery, by repeating the same procedure with 4-mm and 5-mm ETTs. Finally, we compared the efficiencies of aerosol delivery through the 5-mm ETT and the 7.5-mm ETT in a normal room air environment with results obtained under a humidified condition (100% humid air at 37 degrees C). RESULTS: The percentages of aerosol delivered through the ETTs in a normal room air environment were 40%-60%, except for the 4-mm ETT, for which the percentage was 32.7% +/- 6.6% ( P < 0.05 vs that with the 5-mm ETT or the 6-mm ETT). A connector attached to the 15-mm ETT adapter significantly decreased the delivery efficiencies (19.0% +/- 5.8% vs 32.7% +/- 6.6% with the 4-mm ETT, 24.6% +/- 11.8% vs 51.7% +/- 10.8% in the 5-mm ETT) when compared with those without a connector. The delivery efficiencies under the humidified condition in the 5-mm ETT and the 7.5-mm ETT were 65.5% ( P < 0.05) and 89.8% of those in the normal room air environment, respectively. CONCLUSION: The efficiency of delivery of procaterol aerosol through the ETTs was unexpectedly high (approximately half of the total aerosol output per MDI puff in the 5-mm to 8.5-mm ETTs, and one third of the total aerosol output per MDI puff in the 4-mm ETT). A connector attached to the 15-mm ETT adapter noticeably decreased the delivery efficiency. In the smaller-sized ETT, delivery efficiency was significantly lower under the humidified condition than in the normal room air environment.