Assessing a novel second generation laryngeal mask airway using the 'ADEPT' approach: results from the LMA® Protector™ observational study.

To address the problem of lack of clinical evidence for airway devices introduced to the market, the Difficult Airway Society (UK) developed an approach (termed ADEPT; Airway Device Evaluation Project Team) to standardise the model for device evaluation. Under this framework we assessed the LMA Protector, a second generation laryngeal mask airway. A total of 111 sequential adult patients were recruited and the LMA Protector inserted after induction of general anaesthesia. Effective insertion was confirmed by resistance to further distal movement, manual ventilation, and listening for gas leakage at the mouth. The breathing circuit was connected to the airway channel and airway patency confirmed with manual test ventilation at 20 cm H20 (water) pressure for 3 s. Data was collected in relation to the time for placement, intraoperative performance and postoperative performance of the airway device. Additionally, investigators rated the ease of insertion and adequacy of lung ventilation on a 5-point scale. The median (interquartile range [range]) time taken to insertion of the device was 31 (26-40[14-780]) s with the ability to ventilate after device insertion 100 (95% CI 96.7- 100)%. Secondary endpoints included one or more manoeuvres 60.3 (95% CI 50.6-69.5)% cases requiring to assist insertion; a median ease of insertion score of 4 (2-5[3-5]), and a median adequacy of ventilation score of 5 (5-5[4-5]). However, the first time insertion rate failure was 9.9% (95% CI 5.1-17.0%). There were no episodes of patient harm recorded, particularly desaturation. The LMA Protector appears suitable for clinical use, but an accompanying article discusses our reflections on the ADEPT approach to studying airway devices from a strategic perspective.

Cryoshock following cryoablation for hepatocellular carcinoma.

We present a case of profound shock and lactic acidemia occurring in the context of a cryoablative procedure for hepatocellular carcinoma. After out ruling more common possible etiologies, we diagnosed our patient as having a rare cause of shock, unique to these types of cryoablative procedures, known as cryoshock. Cryoablation can result in multiple complications one of which is 'cryoshock', a life-threatening syndrome of multiorgan failure and coagulopathy that carries a high mortality, up to 40%. While the mechanism of cryoshock has not been completely elucidated, it appears to be mediated by the release of cytokines TNF-alpha, IL-1, and IL-6. It is causally associated with complete thaw prior to refreezing and double freeze cycles, as well as volume of and duration of cryotherapy. Cryoreaction, which is a milder phenomenon including chills fever, tachycardia, tachypnea and temporary renal damage has been described after 1% of cryoablation sessions. Reports of the management of cryoshock are scarce and the mainstay of treatment is organ support. While cryoshock has been described in radiology and surgical literature it has not previously been described in anesthesiology literature. We highlight this as a potential serious complication which should be considered by all clinicians involved in these cases.

A randomised trial of bilateral erector spinae plane block vs. no block for thoracolumbar decompressive spinal surgery.

Major spinal surgery causes significant postoperative pain. We tested the efficacy and safety of bilateral erector spinae block on quality of recovery and pain after thoracolumbar decompression. We randomly allocated 60 adults to standard care or erector spinae block. Erector spinae block improved the mean (SD) quality of recovery-15 score at 24 postoperative hours, from 119 (20) to 132 (14), an increase (95%CI) of 13 (4-22), p = 0.0044. Median (IQR [range]) comprehensive complication index was 1 (0-3 [0-5]) in the control group vs. 1 (0-1 [0-4]) after block, p = 0.4. Erector spinae block reduced mean (SD) area under the curve pain during the first 24 postoperative hours: at rest, from 78 (49) to 50 (39), p = 0.018; and on sitting, from 125 (51) to 91 (50), p = 0.009. The cumulative mean (SD) oxycodone consumption to 24 h was 27 (18) mg in the control group and 19 (26) mg after block, p = 0.20. In conclusion, erector spinae block improved recovery and reduced pain for 24 h after thoracolumbar decompression surgery.

The effect of anaesthetic technique during primary breast cancer surgery on neutrophil-lymphocyte ratio, platelet-lymphocyte ratio and return to intended oncological therapy.

Inflammation and immunosuppression contribute to the pathogenesis of cancer. An increased neutrophil-lymphocyte ratio reflects these processes and is associated with adverse cancer outcomes. Whether anaesthetic technique for breast cancer surgery influences these factors, and potentially cancer recurrence, remains unknown. We conducted a secondary analysis in patients enrolled in an ongoing trial of anaesthetic technique on breast cancer recurrence. The primary hypothesis was that postoperative neutrophil-lymphocyte ratio is lower in patients allocated to receive propofol-paravertebral rather than inhalational agent-opioid anaesthesia for primary breast cancer surgery. Among 397 patients, 116 had differential white cell counts performed pre-operatively and postoperatively. Pre-operative neutrophil-lymphocyte ratio was similar in the propofol-paravertebral 2.3 (95%CI 1.8-2.8) and inhalational agent-opioid anaesthesia 2.2 (1.9-3.2) groups, p = 0.72. Postoperative neutrophil-lymphocyte ratio was lower (3.0 (2.4-4.2) vs. 4.0 (2.9-5.4), p = 0.001) in the propofol-paravertebral group. Propofol-paravertebral anaesthesia attenuated the postoperative increase in the neutrophil-lymphocyte ratio.