The effect of remifentanil on propofol requirements to achieve loss of response to command vs. loss of response to pain
When providing total intravenous anaesthesia, careful selection of end-points is required in titrating dose to effect during induction. Although propofol and remifentanil have predominantly different pharmacodynamic effects, they are seen to interact in achieving loss of consciousness and analgesia. To highlight these differences, we performed a double-blind, randomised controlled trial, comparing one group of patients receiving propofol alone (n = 42) with another group receiving remifentanil plus propofol (n = 46) as a target-controlled infusion of remifentanil (Minto; 3 ng.ml−1). Propofol was also titrated using a target-controlled infusion (Marsh effect model) to produce loss of response to tactile and vocal stimuli, and subsequently to loss of response to pain. The effect-site concentration of propofol at which 50% of patients lost tactile/verbal response was 2.9 μg.ml−1 in the propofol only group and 2.4 μg.ml−1 in the remifentanil with propofol group. In contrast, loss of pain response occurred at 4.4 μg.ml−1 in the propofol group, and 2.7 μg.ml−1 in the remifentanil with propofol group, with correspondingly lower bispectral index values. Judicious use of analgesia in total intravenous anaesthesia can have a propofol-sparing effect and potentially minimise the suppression of brain electrical activity.
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.
A national survey of neurological monitoring practice after obstetric regional anaesthesia in the UK
Neuraxial anaesthesia is widely used in obstetrics and neurological complications are rare. However, when they occur, subsequent investigation and management are time-critical and correlate with the extent of neurological recovery. The Third National Audit Project recommended the implementation of guidelines in obstetric epidural management, including advice on monitoring for early signs of problems and acting upon concerns. However, no national guideline exists for postoperative management in the obstetric population. We conducted a national survey of monitoring after obstetric neuraxial blockade and the management of an abnormally prolonged block. We received responses from 112/189 (59.3%) obstetric anaesthetic leads invited to participate. We determined that post-neuraxial blockade monitoring in the UK is highly variable: only 63/112 (56.3%) respondents’ units had a monitoring policy in place, although most of these did not undertake formal neurological monitoring, and a range of different monitoring methods and schedules were employed. In 12/63 (19%) local policies, the first review of neurology was performed at the standard postoperative visit the following day, and 66/112 (58.9%) units had no protocol in place to address emergency management of abnormally prolonged neuraxial blockade. Where a policy was in place, the initial recommended action and the type of imaging used were variable.
Postoperative pulmonary complications are common, with a reported incidence of 2–40%, and are associated with adverse outcomes that include death, longer hospital stay and reduced long-term survival. Enhanced recovery is now a standard of care for patients undergoing elective major surgery. Despite the high prevalence of pulmonary complications in this population, few elements of enhanced recovery specifically address reducing these complications. In 2013, a prevalence audit confirmed a postoperative pulmonary complication rate of 16/83 (19.3%) in patients undergoing elective major surgery who were admitted to critical care postoperatively. A quality improvement team developed and implemented ERAS+, an innovative model of peri-operative care combining elements of enhanced recovery with specific measures aimed at reducing pulmonary complications. ERAS+ was introduced in June 2014, with full implementation in September 2014. Patients were screened during full ERAS+ implementation and again one year following implementation. Following ERAS+ implementation, postoperative pulmonary complications reduced to 24/228 (10.5%). Sustained improvement was evident one year after implementation, with a pulmonary complication rate of 16/183 (8.7%). Median (IQR [range]) length of hospital stay one year after implementation of ERAS+ also improved from 12 (9–15 [4-101]) to 9 (5.5–10.5 [3-81]) days. The ERAS+ pathway is applicable to patients undergoing elective major surgery and appears effective in reducing postoperative pulmonary complications.
Thromboelastography (TEG) or rotational thromboelastometry (ROTEM) to monitor haemostatic treatment in bleeding patients: a systematic review with meta-analysis and trial sequential analysis
Coagulopathy and severe bleeding are associated with high mortality. We evaluated haemostatic treatment guided by the functional viscoelastic haemostatic assays, thromboelastography or rotational thromboelastometry in bleeding patients. We searched for randomised, controlled trials irrespective of publication status, publication date, blinding status, outcomes published or language from date of inception to 5 January 2016 in six bibliographic databases. We included 17 trials (1493 participants), most involving cardiac surgery. Thromboelastography or rotational thromboelastometry seemed to reduce overall mortality compared to any of our comparisons (3.9% vs. 7.4%, RR (95% CI) 0.52 (0.28–0.95); I2 = 0%, 8 trials, 717 participants). However, the quality of evidence is graded as low due to the high risk of bias, heterogeneity, imprecision and low event rate. Thromboelastography or rotational thromboelastometry significantly reduced the proportion of patients transfused with red blood cells (RR (95% CI) 0.86 (0.79–0.94); I2 = 0%, 10 trials, 832 participants), fresh frozen plasma (RR (95% CI) 0.57 (0.33–0.96); I2 = 86%, 10 trials, 832 participants) and platelets (RR (95% CI) 0.73 (0.60–0.88); I2 = 0%, 10 studies, 832 participants). There was no difference in proportion needing surgical re-interventions (RR (95% CI) 0.75 (0.50–1.10); I2 = 0%, 9 trials, 887 participants). Trial sequential analysis of mortality suggests that only 54% of the required information size has been reached so far. Transfusion strategies guided by thromboelastography or rotational thromboelastometry may reduce the need for blood products in patients with bleeding, but the results are mainly based on trials of elective cardiac surgery involving cardiopulmonary bypass, with low-quality evidence.