Shinichi Sakura

Ultrasound guided thoracic paravertebral block in breast surgery.

history of gradually worsening breathlessness and abdominal distension. She described dysphagia and a sensation of a mass at the back of her throat. Her symptoms were worse on lying flat. She had a history of hypothyroidism and Raynaud’s phenomenon, was taking thyroxine and was normally completely independent. Physical examination revealed a woman in obvious respiratory distress with marked inspiratory stridor, respiratory rate of 24 breaths. min and using her accessory muscles of respiration. Auscultation revealed no wheeze or crepitation. Arterial blood gases on 10 l.min oxygen revealed pH 7.38, PCO2 4.25 kPa, pO2 8.52 kPa. Abdominal examination revealed gross abdominal distension with normal bowel sounds. X-ray showed marked oesophageal and small bowel dilatation. Computerised Tomography of her chest and abdomen (Fig. 2) revealed oesophageal distension compressing the distal trachea. In the emergency department, she was treated with Heliox 28% and insertion of large-bore nasogastric tube with prompt resolution of symptoms. She made a good recovery and was followed up by the gastroenterology team. Oesphageal achalasia is an idiopathic motility disorder of the oesophagus, characterised by impaired relaxation of the lower oesophageal sphincter and oesophageal aperistalsis, with resultant dilatation of the oesophagus [1–3]. Respiratory complications can occur secondary to food regurgitation, with aspiration and respiratory tract infection as a result. Prompt recognition of this condition is critical to treatment, the mainstay of which is insertion of a nasogastric tube, although sublingual nitrates have been used with good effect. Definitive treatment includes endoscopic balloon dilatation of the lower oesophageal sphincter, surgical myotomy or botulinum toxin injection. Acute airway obstruction with stridor is a very rare presentation of achalasia. This case is highlighted to anaesthetists as they may be called upon to assess these patients in the accident and emergency department.

Continuous local anesthetic infusion through ultrasound-guided rectus sheath catheters

To the Editor, Although epidural analgesia is a gold standard technique for postoperative abdominal analgesia, its use is sometimes limited due to perioperative anticoagulant therapy and undesirable complications such as hypotension. Rectus sheath (RS) blocks can provide alternative analgesia after midline abdominal surgery. This ultrasound-guided technique has recently gained popularity owing to fewer complications and a higher success rate. Since the duration of the RS block is limited by single injection, it is necessary to develop longer lasting analgesic methods for smooth postoperative recovery. A few attempts using RS catheters have been reported, including continuous administration of a large volume (42 mL hr) of local anesthetic. However, continuous high-dose local anesthetic infusion may induce local anesthetic systemic toxicity. We report cases in which continuous low-dose local anesthetic infusion through ultrasound-guided RS catheters showed effective postoperative midline abdominal analgesia. Written consent for publication was obtained from each patient.

Prolonged cardiac arrest unveiled silent sick sinus syndrome during general and epidural anesthesia

Patients who have silent sick sinus syndrome (SSS) can show various unexpected arrhythmias during surgery. The severity of these bradyarrythmias is affected by anesthetic methods. We report a unique case of a patient with silent SSS who developed 40 s of asystole under combined general and epidural anesthesia. A 40-year-old woman with no apparent cardiac disease underwent abdominal hysterectomy. General anesthesia was induced and maintained with propofol, fentanyl, and vecuronium combined with thoracic epidural anesthesia. During surgery, severe bradycardia, triggered by peritoneal manipulation, occurred, leading to 40 s of asystole. She was diagnosed as having SSS by a postoperative 24-h Holter electrocardiogram. We propose that the possible existence of SSS should be kept in mind even in a patient who shows no abnormalities on routine preoperative examination, especially in those in whom vagomimetic anesthetic methods are used.

Haemodynamic effects of thoracic epidural anaesthesia during induction of anaesthesia: an investigation into the effects of tracheal intubation during target-controlled infusion of propofol*

We compared haemodynamic changes following induction of anaesthesia with propofol during tracheal intubation with and without epidural anaesthesia. Nineteen patients were divided into two groups to receive epidurally administered saline (Group C) or lidocaine 1.5% (Group E). The propofol infusion was started to produce blood concentrations of 3 μg.ml−1, and following fentanyl and vecuronium administration, tracheal intubation was performed. Mean arterial blood pressure (MBP), heart rate (HR), Bispectral index and effect‐site propofol concentration were recorded. Time to loss of consciousness was significantly shorter in Group E than in Group C. The effect‐site propofol concentration at loss of consciousness was significantly lower in Group E than in Group C. MBP and HR were significantly lower following propofol induction in both groups, and were significantly increased following intubation in Group C but not in Group E. In conclusion, epidural anaesthesia did not produce profound hypotension following induction of anaesthesia and produced a reduction in the haemodynamic response to tracheal intubation during a target controlled infusion of propofol.

Monitored anesthesia care based on ultrasound-guided subcostal transversus abdominis plane block for continuous ambulatory peritoneal dialysis catheter surgery: case series

Planning safe perioperative management for patients undergoing continuous ambulatory peritoneal dialysis (CAPD) catheter surgery (insertion and extraction of the catheter) is often difficult because many of these patients not only have renal insufficiency but also have co-existing disorders, such as heart diseases. As increased indications for perioperative anticoagulation therapy have limited the choice of anesthesia, selecting an appropriate anesthetic method, particularly for patients with poor systemic conditions, is becoming more challenging. We report seven cases of CAPD catheter surgery successfully managed by monitored anesthesia care using subcostal transversus abdominis plane (TAP) block with additional local anesthetic infiltration and analgesics. Despite co-existing cardiac disease and/or coagulation disorders, all patients were safely managed without any other major anesthetic methods. Subcostal TAP block is a useful anesthetic option for CAPD catheter surgery, particularly for patients with poor systemic conditions and/or in whom neuraxial blocks are contraindicated.

Research on local anesthetic neurotoxicity using intrathecal and epidural rat models

facilitate restricted distribution, catheters are placed with their tips among the nerve roots of the cauda equina [4] or very close to the caudal end of the epidural space [6]. Because local anesthetic solutions rarely induce neurologic injury in clinical practice, the observation of neurotoxic effects requires higher doses of these agents. Thus, a high concentration of local anesthetic is used, and/or continuous infusion is done in our models. Figure 1 shows a typical protocol for our studies, in which functional and histological fi ndings have been obtained. Neurologic function was examined with the tail-fl ick test and the paw-pressure test. Histological examination of the nerve roots and spinal cord was performed using light and electron microscopy. Experiments using our in vivo models have produced results that can answer some important questions, one of which is whether local anesthetic neurotoxicity is dose-dependent. We continuously administered 5% lidocaine, with or without glucose, for 30 min, 1 h, 2 h, or 4 h in our rat model [7]. The results of the tail-fl ick test, performed 4 days after the infusion, showed that rats given lidocaine for longer periods, regardless of glucose, were more likely to incur defi cits. Permanent neurologic injury, including cauda equina syndrome, has been reported to be associated with lidocaine in many cases. Results of experiments where we administered bupivacaine and lidocaine intrathecally as equipotent solutions have proven that bupivacaine is less neurotoxic than lidocaine, suggesting that neurotoxicity differs among local anesthetics [8]. There is a considerable difference between spinal and epidural anesthesia in the number of reported cases of nerve injury. This fact is probably because the neurotoxicity of epidural and intrathecal local anesthetics is different. Our models permit a comparison of the effects of anesthetics administered intrathecally and epidurally. When intrathecal and epidural lidocaine were administered in rats to produce similar anesthetic effects, persistent functional impairment occurred only after Serious neurologic complications rarely occur after neuraxial blockade. However, reports of cauda equina syndrome after continuous spinal anesthesia, published in 1991 [1], generated concern regarding the potential neurotoxicity of local anesthetics used clinically. Cauda equina syndrome results from injury to the sacral nerve roots and is characterized by varying degrees of bladder and bowel dysfunction, perineal sensory loss, and lower extremity motor weakness. Reviews of such cases and results of studies using anatomic models [2,3] have suggested that the combination of maldistribution and a relatively high dose of local anesthetic may result in toxic exposure of neural tissue. To identify the factors that contribute to local anesthetic injury, and to pursue investigations of the mechanisms underlying this injury, we have developed in vivo rat models, in which local anesthetic can be continuously administered intrathecally or epidurally [4–6]. To