Guidelines for safe transfer of the brain-injured patient: trauma and stroke, 2019: Guidelines from the Association of Anaesthetists and the Neuro Anaesthesia and Critical Care Society.

The location of care for many brain-injured patients has changed since 2012 following the development of major trauma centres. Advances in management of ischaemic stroke have led to the urgent transfer of many more patients. The basis of care has remained largely unchanged, however, with emphasis on maintaining adequate cerebral perfusion as the key to preventing secondary injury. Organisational aspects and training for transfers are highlighted, and we have included an expanded section on paediatric transfers. We have also provided a table with suggested blood pressure parameters for the common types of brain injury but acknowledge that there is little evidence for many of our recommendations. These guidelines remain a mix of evidence-based and consensus-based statements. We have received assistance from many organisations representing clinicians who care for these patients, and we believe our views represent the best of current thinking and opinion. We encourage departments to review their own practice using our suggestions for audit and quality improvement.

Targeted temperature management in patients with intracerebral haemorrhage, subarachnoid haemorrhage, or acute ischaemic stroke: consensus recommendations.

BACKGROUND: A modified Delphi approach was used to identify a consensus on practical recommendations for the use of non-pharmacological targeted temperature management in patients with intracerebral haemorrhage, subarachnoid haemorrhage, or acute ischaemic stroke with non-infectious fever (assumed neurogenic fever). METHODS: Nine experts in the management of neurogenic fever participated in the process, involving the completion of online questionnaires, face-to-face discussions, and summary reviews, to consolidate a consensus on targeted temperature management. RESULTS: The panel's recommendations are based on a balance of existing evidence and practical considerations. With this in mind, they highlight the importance of managing neurogenic fever using a single protocol for targeted temperature management. Targeted temperature management should be initiated if the patient temperature increases above 37.5°C, once an appropriate workup for infection has been undertaken. This helps prevent prophylactic targeted temperature management use and ensures infection is addressed appropriately. When neurogenic fever is detected, targeted temperature management should be initiated rapidly if antipyretic agents fail to control the temperature within 1 h, and should then be maintained for as long as there is potential for secondary brain damage. The recommended target temperature for targeted temperature management is 36.5-37.5°C. The use of advanced targeted temperature management methods that enable continuous, or near continuous, temperature measurement and precise temperature control is recommended. CONCLUSIONS: Given the limited heterogeneous evidence currently available on targeted temperature management use in patients with neurogenic fever and intracerebral haemorrhage, subarachnoid haemorrhage, or acute ischaemic stroke, a Delphi approach was appropriate to gather an expert consensus. To aid in the development of future investigations, the panel provides recommendations for data gathering.

A randomised controlled trial examining the effect of acupuncture at the EX-HN3 (Yintang) point on pre-operative anxiety levels in neurosurgical patients.

Pre-operative anxiety is an unpleasant state of psychological distress that occurs in up to 87% of patients awaiting neurosurgical procedures. Sedative medication is undesirable in this population due to the need for early postoperative neurological assessment. Acupuncture has previously been shown to reduce pre-operative anxiety, but studies involving neurosurgical patients are lacking. This single-centre, prospective, randomised controlled trial was designed to determine the effect of acupuncture at the EX-HN3 (Yintang point) on pre-operative anxiety levels in neurosurgical patients. The study was prospectively registered before participant recruitment. After measuring baseline anxiety levels, 128 patients were randomly allocated in a 1:1 ratio by a web-based computer program to receive either acupuncture at the EX-HN3 (Yintang) point (acupuncture group) or no intervention (control group). Participants were not blinded, but all analyses were performed by a member of the research team who was unaware of the group allocation. The primary outcome measure was anxiety level after 30 min, as measured by the six-item short form of the State-Trait Anxiety Inventory (possible score range 20-80). Sixty-two patients in each group were subsequently analysed. Median (IQR [range]) anxiety State-Trait Anxiety Inventory score reduced significantly in the acupuncture group (46.7 (36.7-53.3 [23.3-70.0]) to 40.0 (30.0-46.7) [20.0-53.3]), p < 0.001), with no change seen in the control group (41.7 (33.3-53.3 [20.0-76.7]) to 43.3 (36.7-50.0 [20.0-76.7]), p = 0.829). There were no adverse events in either group. Acupuncture at the EX-HN3 point reduces pre-operative anxiety levels in patients awaiting neurosurgery.

The role and limitations of EEG-based depth of anaesthesia monitoring in theatres and intensive care.

In this article we will look at some of the principles in processed EEG monitoring as applied to bispectral index (BIS). We outline why BIS should be regarded as a 'memory' monitor which in most circumstances reflects the depth of sedation or anaesthesia in particular patients. Its limitation in paralysed and non-paralysed patients must be understood in order for this monitor to be used safely. Finally, its emerging use in critical care will be explored.

An evaluation of factors influencing the assessment time in a nurse practitioner-led anaesthetic pre-operative assessment clinic.

Elective patients undergoing anaesthetic pre-operative assessment are usually allocated the same period of time with a nurse practitioner, leading to potential inefficiencies in patient flow through the clinic. We prospectively collected data on 8519 patients attending a pre-operative assessment clinic. The data set were split into derivation and validation cohorts. Standard multiple regressions were used to construct a model in the derivation cohort, which was then tested in the validation cohort. Due to missing data, 2457 patients were not studied, leaving 5892 for analysis (3870 in the derivation cohort and 2022 in the validation cohort). The mean (SD) pre-operative assessment time was 46 (12) min. Age, ASA physical status, nurse practitioner and surgical specialty all influenced the time spent in pre-operative assessment. The predictive equations calculated using the derivation cohort, based on age and ASA physical status, correctly estimated duration of consultation to within 20% of the maximum predicted time in 74.2% of the validation cohort. We conclude that if age and ASA physical status are known before the pre-operative assessment consultation, it could allow appointment times to be allocated more accurately.

Awake intubation and awake prone positioning of a morbidly obese patient for lumbar spine surgery.

We describe the awake fibreoptic intubation followed by awake prone positioning of a woman weighing 180 kg with body mass index of 62 kg.m(-2) requiring emergency lumbar discectomy for cauda equina syndrome. This approach was taken to overcome difficulties in transfering an anaesthetised patient on to the operating table. Following topical anaesthesia with lidocaine and low-dose remifentanil infusion, oral intubation was performed using a split oral airway to guide the fibrescope. The patient positioned herself on the Jackson operating table, following which general anaesthesia was induced. This technique optimised protection of the patient's eyes and other pressure areas while preventing undue cardiorespiratory compromise. The patient tolerated the procedure well, and later confirmed that she would consent to undergoing the same procedure again if further surgery became necessary.

A randomised single blinded study of the administration of pre-warmed fluid vs active fluid warming on the incidence of peri-operative hypothermia in short surgical procedures.

We compared the effect of delivering fluid warmed using two methods in 76 adult patients having short duration surgery. All patients received a litre of crystalloid delivered either at room temperature, warmed using an in-line warming device or pre-warmed in a warming cabinet for at least 8 h. The tympanic temperature of those receiving fluid at room temperature was 0.4 °C lower on arrival in recovery when compared with those receiving fluid from a warming cabinet (p = 0.008). Core temperature was below the hypothermic threshold of 36.0 °C in seven (14%) patients receiving either type of warm fluid, compared to eight (32%) patients receiving fluid at room temperature (p = 0.03). The administration of 1 l warmed fluid to patients having short duration general anaesthesia results in higher postoperative temperatures. Pre-warmed fluid, administered within 30 min of its removal from a warming cabinet, is as efficient at preventing peri-operative hypothermia as that delivered through an in-line warming system.

Comparison of the performance of four laryngoscopes in a high-fidelity simulator using normal and difficult airway.

BACKGROUND: Novel laryngoscopes may demonstrate advantages over the traditional Macintosh laryngoscope for difficult airways. Our study compared Glidescope laryngoscope, Bonfils fibrescope, and CTrach intubating laryngeal mask airway with the Macintosh laryngoscope in a simulated normal and difficult airway, considering the additional effect of previous intubation experience. METHODS: Twenty-two non-anaesthetists, 21 trainees, and 20 consultant anaesthetists attempted tracheal intubation of a Laerdal SimMan manikin, comparing a normal with a difficult airway scenario for each intubation device. The time taken to view the vocal cords and time to intubate were recorded. Also success rate and ease of use for each device were scored, alongside scope preference for each scenario. RESULTS: Time to intubate was significantly shorter with the Macintosh compared with all three novel devices. All the devices had a high first-attempt success rate, but the Glidescope had a 100% first time successful intubation for all participants in both a normal and a difficult airway. Non-anaesthetists took significantly longer time to intubate compared with consultant anaesthetists, but there was no difference between trainee and consultant anaesthetists. Higher proportions of participants found the Glidescope easy to use, compared with other devices. For the normal airway, the Macintosh was the preferred device, but for the difficult airway, the Glidescope was favoured. CONCLUSIONS: In this study, the Macintosh laryngoscope outperformed the other devices. However, the Glidescope was considered easy to use regardless of previous experience and was the preferred device for the simulated difficult airway.

Effect of prewarming on post-induction core temperature and the incidence of inadvertent perioperative hypothermia in patients undergoing general anaesthesia.

BACKGROUND: Inadvertent perioperative hypothermia (IPH) occurs in many patients because warming techniques are insufficient to counteract thermal redistribution resulting from the ablation of thermoregulatory vasoconstriction associated with anaesthesia. We tested the efficiency of a preoperative forced-air warming (FAW) device (Bair Paws) in preventing IPH. METHODS: Sixty-eight adult patients undergoing spinal surgery under general anaesthesia were randomized to receive either normal care or prewarming for 60 min, at 38 degrees C, using the Bair Paws system. All patients received routine FAW intraoperatively. RESULTS: Thirty-one patients were prewarmed and 37 patients were in the control group. There was a 0.3 degrees C smaller decrease in mean core temperature in the prewarmed group at 40, 60, and 80 min post-induction (P< or =0.05). Temperature was maintained above the hypothermic threshold of 36 degrees C in 21 (68%) patients in the prewarmed group, compared with 16 (43%) patients in the control group (P<0.05). CONCLUSIONS: Preoperative warming using the Bair Paws system results in smaller decreases in core temperature intraoperatively and less IPH in patients undergoing spinal surgery under general anaesthesia.

The influence of changes in end-tidal carbon dioxide upon the Bispectral Index.

Carbon dioxide is known to affect consciousness in animals and humans. We surmised that changes in end-tidal carbon dioxide during anaesthesia might affect the Bispectral Index. Twenty-four patients due to undergo surgery were anaesthetised with fentanyl and a propofol infusion. The Bispectral Index, pulse rate and blood pressure were recorded while end-tidal carbon dioxide levels were changed. The patients acted as their own controls as they were subjected to high, normal and low levels of end-tidal carbon dioxide (3-12 kPa) according to a randomised sequence. There were no changes in the Bispectral Index or haemodynamic variables resulting from manipulation of the end-tidal carbon dioxide. At the level of hypnosis involved in this study, changes in end-tidal carbon dioxide, within the range tested, do not result in changes in the Bispectral Index.