Masakazu Kotoda

Cardiac arrest after spinal anesthesia in a patient with neurally mediated syncope.

We present the case of cardiac arrest in a patient with neurally mediated syncope (NMS). A 66-year-old male patient was scheduled to undergo right inguinal hernioplasty. He had a history of syncope, which occurred a few times a year in childhood and once a year recently. One minute after the second spinal injection, cardiac arrest (asystole) developed. Sinus rhythm was restored by cardiac massage and intravenous administration of atropine and ephedrine. The operation was cancelled. The patient was diagnosed as NMS by a cardiologist. Four months later, right inguinal hernioplasty was performed, uneventfully, under general anesthesia. High sympathetic blockade due to spinal anesthesia and transient withdrawal of sympathetic tone and increase in vagal discharge due to NMS could be the main causes of the cardiac arrest. If the patient has any possibility of NMS, anesthesiologists should consider the possibility of cardiac arrest after spinal anesthesia.

The effects of Patent Blue dye on peripheral and cerebral oxyhaemoglobin saturations

We measured the effect of Patent Blue dye on oxyhaemoglobin saturations after injection into breast tissue: 40 women had anaesthesia for breast surgery maintained with sevoflurane or propofol (20 randomly allocated to each). Saturations were recorded with a digital pulse oximeter, in arterial blood samples and with a cerebral tissue oximeter before dye injection and 10, 20, 30, 40, 50, 60, 75, 90, 105 and 120 min afterwards. Patent Blue did not decrease arterial blood oxyhaemoglobin saturation, but it did reduce mean (SD) digital and cerebral oxyhaemoglobin saturations by 1.1 (1.1) % and 6.8 (7.0) %, p < 0.0001 for both. The falsely reduced oximeter readings persisted for at least 2 h. The mean (SD) intra‐operative digital pulse oxyhaemoglobin readings were lower with sevoflurane than propofol, 97.8 (1.2) % and 98.8 (1.0) %, respectively, p < 0.0001.

Effects of hyperventilation on cerebral oxygen saturation estimated using near-infrared spectroscopy: A randomised comparison between propofol and sevoflurane anaesthesia

BACKGROUND Near-infrared spectroscopy estimates cerebral regional tissue oxygen saturation (rSO2), which may decrease under hyperventilation. Propofol and sevoflurane act differently on cerebral blood vessels. Consequently, cerebral blood flow during hyperventilation with propofol and sevoflurane anaesthesia may differ. OBJECTIVES The first aim of this study was to compare the changes in rSO2 between propofol and sevoflurane anaesthesia during hyperventilation. The second aim was to assess changes in rSO2 with ventilation changes. DESIGN A randomised, open-label study. SETTING University of Yamanashi Hospital, Yamanashi, Japan from January 2014 to September 2014. PARTICIPANTS Fifty American Society of Anesthesiologists physical status 1 or 2 adult patients who were scheduled for elective abdominal surgery were assigned randomly to receive either propofol or sevoflurane anaesthesia. Exclusion criterion was a known history of cerebral disease such as cerebral infarction, cerebral haemorrhage, transient ischaemic attack and subarachnoid haemorrhage. INTERVENTIONS After induction of anaesthesia but before the start of surgery, rSO2, arterial carbon dioxide partial pressure (PaCO2) and arterial oxygen saturation were measured. Measurements were repeated at 5-min intervals during 15 min of hyperventilation with a PaCO2 around 30 mmHg (4 kPa), and again after ventilation was normalised. MAIN OUTCOME MEASURES The primary outcome was the difference of changes in rSO2 between propofol anaesthesia and sevoflurane anaesthesia during and after hyperventilation. The second outcome was change in rSO2 after the initiation of hyperventilation and after the normalisation of ventilation. RESULTS Changes of rSO2 during hyperventilation were −10 ± 7% (left) and −11 ± 8% (right) in the propofol group, and −10 ± 8% (left) and −9 ± 7% (right) in the sevoflurane group. After normalisation of PaCO2, rSO2 returned to baseline values. Arterial oxygen saturation remained stable throughout the measurement period. The rSO2 values were similar in the propofol and the sevoflurane groups at each time point. CONCLUSION The effects of hyperventilation on estimated rSO2 were similar with propofol and sevoflurane anaesthesia. Changes in rSO2 correlated well with ventilation changes. TRIAL REGISTRATION Japan Primary Registries Network (JPRN); UMIN-CTR ID; UMIN000010640

Ultrasound-guided out-of-plane obturator nerve block.

‘microbial broth’, and we note that only the antibacterial effects of SaniCloth CHG 2% on E. coli and MRSA were measured. With input from the Medicines and Healthcare products Regulatory Agency’s Microbiology Advisory Committee, the AAGBI guidelines on infection control in anaesthesia [2] risk-stratify devices and methods of decontamination into high/intermediate/low, depending on the penetration of skin and mucous membranes. Bougies, along with other airway devices, are highly likely to be in contact with mucous membranes, and to become contaminated, and are therefore designated intermediate-risk. As such, they require high-level disinfection which would not be achieved with chlorhexidine 2%/alcohol 70% alone. It follows that low-level disinfection of reusable bougies is inadequate to prevent transmission of the majority of bacteria, viruses, fungi and spores. Perhaps more importantly, the authors have not commented on the prevention of transmission of prion proteins, such as those causing variant Creutzfeldt-Jakob disease (vCJD) [3]. Sani-Cloth CHG 2% disinfection would be insufficient to minimise the risk of transmission of vCJD adequately, and it is predominantly for this reason that disposable airway devices are recommended.

Anesthetic Management of a Child With Jeune Syndrome for Tracheotomy: A Case Report.

Jeune syndrome is a rare autosomal-recessive skeletal disorder. Anesthetic management of these patients is often difficult because of thoracic and lung hypoplasia. A 5-month-old boy with Jeune syndrome was scheduled to undergo a tracheotomy. Despite 5-minute preoxygenation with continuous positive airway pressure, the patient’s oxygen saturation rapidly dropped during the induction of anesthesia. The continuous positive airway pressure should have been titrated to effective tidal volume during preoxygenation to recruit the patient’s functional residual capacity and to prevent desaturation. During tracheotomy, volume-controlled ventilation with a high respiratory rate and sufficient inspiratory time effectively improved the patient’s respiratory status.