A randomised,non‐crossover study of the GuardianCPV™ Laryngeal Mask versus the LMA Supreme™ in paralysed,anaesthetised female patients

We investigated the hypothesis that the oropharyngeal leak pressure would differ between the GuardianCPV? and the LMA Supreme? in anaesthetised patients. We randomly assigned 120 patients to receive either the GuardianCPV or the LMA Supreme for airway management. Oropharyngeal leak pressure was measured during cuff inflation from 0 to 40 ml in 10‐ml steps. In addition, intracuff pressure, fibreoptic position of the airway and drain tube, device insertion success, ventilation success, blood staining and airway morbidity were determined. Mean (SD) oropharyngeal leak pressures for clinically acceptable cuff volumes of 20–40 ml were 31 (7) cmH₂O for the GuardianCPV and 27 (7) cmH₂O for the LMA Supreme (p < 0.0001); mean (SD) intracuff pressures were 68 (33) cmH₂O and 88 (43) cmH₂O (p < 0.0001), respectively. We found no differences in device insertion success, ventilation success, fibreoptic position of the airway and drain tube, blood staining or airway morbidity. We conclude that the oropharyngeal leak pressure is better for the GuardianCPV than for the LMA Supreme in anaesthetised patients.     

Patient‐controlled oral analgesia versus nurse‐controlled parenteral analgesia after caesarean section: a randomised controlled trial

We assessed the effectiveness of early patient‐controlled oral analgesia compared with parenteral analgesia in a randomised controlled non‐inferiority trial of women undergoing elective caesarean section under regional anaesthesia. Seventy‐seven women received multimodal paracetamol, ketoprofen and morphine analgesia. The woman having patient‐controlled oral analgesia were administered four pillboxes on the postnatal ward containing tablets and instructions for self‐medication, the first at 7 h after the spinal injection and then three more at 12‐hourly intervals. Pain at rest and on movement was evaluated using an 11‐point verbal rating scale at 2 h and then at 6‐hourly intervals for 48 h. The pre‐defined non‐inferiority limit for the difference in mean pain scores (patient‐controlled oral analgesia minus parenteral) was one. The one‐sided 95% CI of the difference in mean pain scores was significantly lower than one at all time‐points at rest and on movement, demonstrating non‐inferiority of patient‐controlled oral analgesia. More women used morphine in the patient‐controlled oral analgesia group (22 (58%)) than in the parenteral group (9 (23%); p = 0.002). The median (IQR [range]) number of morphine doses in the patient‐controlled oral analgesia group was 2 (1–3 [1–7]) compared with 1 (1–1 [1–2]); p = 0.006) in the parenteral group. Minor drug errors or omissions were identified in five (13%) women receiving patient‐controlled oral analgesia. Pruritus was more frequent in the patient‐controlled oral analgesia group (14 (37%) vs 6 (15%) respectively; p = 0.03), but no differences were noted for other adverse events and maternal satisfaction. After elective caesarean section, early patient‐controlled oral analgesia is non‐inferior to standard parenteral analgesia for pain management, and can be one of the steps of an enhanced recovery process.     

The McGrath® Series 5 videolaryngoscope vs the Macintosh laryngoscope: a randomised,controlled trial in patients with a simulated difficult airway

We compared the McGrath^® Series 5 videolaryngoscope with the Macintosh laryngoscope in a simulated difficult airway, using manual in‐line stabilisation in 88 anaesthestised patients of ASA physical status 1‐2. The primary outcome was laryngoscopic view. Secondary outcomes included rates of successful tracheal intubation and complications. A Cormack and Lehane grade‐1 or ‐2 view was found in all patients when using the McGrath compared with 45 (51%, p < 0.0001) using the Macintosh laryngoscopes. The mean (SD) percentage of glottic opening was 82 (23)% using the McGrath compared with 13 (23)% using the Macintosh (p < 0.0001). In 66 out of 88 patients (75%), the McGrath improved the glottic view by one to three grades compared with the Macintosh (p < 0.001). Intubation of the trachea was successful in all patients using the McGrath, while the Macintosh was successful in 26 (59%, p < 0.001). There was no significant difference in the complication rates between the devices.     

The impact of trained assistance on error rates in anaesthesia: a simulation‐based randomised controlled trial*

Trained assistance for the anaesthetist appears likely to improve safety in anaesthesia. However, there are few objective data to support this assumption, and the requirement for a trained assistant is not universally enforced. We applied a simulation‐based model developed in previous work to test the hypothesis that the presence of a trained assistant reduces error in anaesthesia. Ten randomly selected anaesthetists, five trained anaesthetic technicians and five theatre nurses without training in anaesthesia participated in two simulated emergencies, with anaesthetists working alternately with a technician or a nurse. The mean (SD) error rate per scenario was 4.75 (2.9). There were significantly fewer errors in the technician group than the nurse group (33 vs 62, p = 0.01) and this difference remained significant when errors were weighted for severity. This provides objective evidence supporting the requirement for trained assistance to the anaesthetist, and furthermore, demonstrates that a simulation‐based model can provide rigorous evidence on safety interventions in anaesthesia.     

Retention of laryngoscopy skills in medical students: a randomised,cross‐over study of the Macintosh,A.P. Advance™, C‐MAC® and Airtraq® laryngoscopes

In addition to being effective and easy to learn how to use, the ideal laryngoscope should be associated with minimal reduction in skill performance during gaps in practice over time. We compared the time taken to intubate the trachea of a manikin by novice medical students immediately after training, and then after 1 month, with no intervening practice. We designed a two‐period, four‐group, randomised, cross‐over trial to compare the Macintosh, Venner^™ A.P. Advance^™ with difficult airway blade, C‐MAC^® with D‐Blade and Airtraq^® with wireless video‐viewer. A bougie was used to aid intubation with the Macintosh and the C‐MAC. After training, there was no significant difference in median (IQR [range]) intubation time using the videolaryngoscopes compared with the Macintosh, which took 30 (26.5–35 [12–118])s. One month later, the intubation time was longer using the C‐MAC (41 (29.5–52 [20–119])s; p = 0.002) and A.P. Advance (40 (28.5–57.5 [21–107])s; p = 0.0003)m compared with the Macintosh (27 (21–29 [16–90])s); there was no difference using the Airtraq (27 (20.5–32.5 [15–94])s; p = 0.258) compared with the Macintosh. While skill acquisition after a brief period of learning and practice was equal for each laryngoscope, performance levels differed after 1 month without practice. In particular, the consistency of performance using the C‐MAC and A.P. Advance was worse compared with the Macintosh and the Airtraq. While the clinical significance of this is doubtful, we believe that reliable and consistent performance at laryngoscopy is desirable; for the devices that we tested, this requires regular practice.     

A comparison of the respiratory effects of oxycodone versus morphine: a randomised,double‐blind,placebo‐controlled investigation*

Oxycodone’s respiratory profile (particularly the extent of respiratory depression in comparison to morphine) remains to be fully characterised in the peri‐operative period. We randomly assigned ASA 1‐2 adults for elective surgery under general anaesthesia to receive saline, morphine 0.1 mg.kg^?1, or oxycodone 0.05 mg.kg^?1, 0.1 mg.kg^?1, or 0.2 mg.kg^?1. Results were obtained from six patients in the saline group, 12 patients in the groups receiving morphine 0.1 mg.kg^?1, oxycodone 0.05 mg.kg^?1 and 0.1 mg.kg^?1, and from 10 patients who received oxycodone 0.2 mg.kg^?1. Patients were breathing spontaneously and minute ventilation monitored with a wet wedge spirometer for 30 min. All active groups demonstrated significant respiratory depression compared to saline (p < 0.0001 for all groups). The mean (SD) reduction in minute volume from baseline was 22.6% (10.4%) for the morphine 0.1 group and 53.3% (27.2%), 74.4% (12.9%) and 88.6% (13.5%) for the oxycodone 0.05, 0.1 and 0.2 groups, respectively, with significant dose dependent differences between oxycodone groups (p = 0.0007). The extent and speed of onset of oxycodone induced respiratory depression was dose dependent and greater than an equivalent dose of morphine.     

The performance of rigid scopes for tracheal intubation: a randomised,controlled trial in patients with a simulated difficult airway

We compared the Bonfils^? and SensaScope^? rigid fibreoptic scopes in 200 patients with a simulated difficult airway randomised to one of the two devices. A cervical collar inhibited neck movement and reduced mouth opening to a mean (SD) of 23 (3) mm. The primary outcome parameter was overall success of tracheal intubation; secondary outcomes included first‐attempt success, intubation times, difficulty of intubation, fibreoptic view and side‐effects. The mean (95% CI) overall success rate was 88 (80–94)% for the Bonfils and 89 (81–94)% for the SensaScope (p = 0.83). First‐attempt intubation success rates were 63 (53–72)% for the Bonfils and 72 (62–81)% for the SensaScope (p = 0.17). Median (IQR [range]) intubation time was significantly shorter with the SensaScope (34 (20–84 [5–240]) s vs. 45 (25–134 [12–230]) s), and fibreoptic view was significantly better with the SensaScope (full view of the glottis in 79% with the SensaScope vs. 61% with the Bonfils). This might be explained by its steerable tip and the S‐formed shape, contributing to better manoeuvrability. There were no differences in the difficulty of intubation or side‐effects.     

A randomised cross‐over trial comparing the McGrath® Series 5 videolaryngoscope with the Macintosh laryngoscope in patients with cervical spine immobilisation

We compared the performance of the McGrath^® Series 5 videolaryngoscope with the Macintosh laryngoscope in 49 patients without suspected cervical spine pathology, whose cervical spine was immobilised using a semi‐rigid collar. The primary outcome was the view obtained at laryngoscopy. Secondary outcomes included time to tracheal intubation, rates of successful intubation and incidence of complications. In all patients, the view was better (92%) or the same (8%) in the McGrath group versus the Macintosh group (p < 0.01). There were no failed intubations in the McGrath group and seven (28%) in the Macintosh group (p < 0.02). There was no statistical difference in time taken to intubate or incidence of complications. We conclude that the McGrath^® Series 5 is a superior laryngoscope when cervical spine immobilisation is maintained during tracheal intubation.     

Remifentanil for labour analgesia: a double‐blinded,randomised controlled trial of maternal and neonatal effects of patient‐controlled analgesia versus continuous infusion

This trial aimed to compare the maternal and neonatal effects of remifentanil given by patient‐controlled analgesia (PCA) or continuous infusion for labour analgesia. Patient controlled analgesia was administered using increasing stepwise boluses from 0.1 to 0.4 μg.kg^?1 (0.1 μg.kg^?1 increment, 2 min lockout, n = 30). Continuous infusion used rates from 0.05 to 0.2 μg.kg^?1.min^?1 (0.05 μg.kg^?1.min^?1 increment, n = 30). Dose increments were given on request. Women reported lowest pain scores (median (IQR [range]) of 3 (2–4 [2–5]) for PCA and 4 (3–5.25 [3–7]) for continuous infusion (p = 0.004) at 60 min after the beginning of analgesia. The mean (SD) remifentanil umbilical vein/maternal artery ratio in the PCA and infusion groups were 0.74 (0.45) vs 0.70 (0.52), respectively (p = 0.776). The mean (SD) umbilical artery/umbilical vein ratios were 0.31 (0.12) vs 0.26 (0.07), respectively (p = 0.088). Maternal and neonatal adverse reactions of remifentanil were similar between the two groups. The total remifentanil consumption (median (IQR [range]) during PCA administration was lower than continuous infusion, 1.34 (1.22–1.48 [0.89–1.69]) mg vs 1.49 (1.35–1.61 [1.12–1.70] mg; p = 0.011). The results suggest that remifentanil PCA provides better pain relief and similar placental transfer compared with continuous infusion.     

The effects of calcineurin inhibitors on prostanoid synthesis: a randomized cross‐over study in healthy humans

The calcineurin inhibitors (CNIs) cyclosporine (CsA) and tacrolimus (Tac) are implicated in post‐transplant complications such as cardiovascular morbidity. Prostanoids are fatty acid‐derived compounds essential for controlling cardiovascular homeostasis. We tested the hypothesis that CNIs suppress cyclooxygenase (COX)‐2‐derived prostacyclin (PGI) and increase thromboxane synthesis in humans. Ten healthy men underwent 5‐h infusions of CsA, Tac, and saline in a randomized, double‐blind, cross‐over study. Blood and urine samples were collected before and after the infusion of each drug/saline, to measure PGI and thromboxane metabolites. CsA decreased whole‐blood COX‐2 activity by 39% (P = 0.05) and basal plasma 6‐keto‐PGF_1α levels by 31%, only nonsignificantly. Urine excretion of PGI‐M and TxB₂ did not change significantly after CsA infusion. Tac decreased TxB₂ in the COX‐1 ex vivo assay by 30% (P = 0.03), while no changes were seen in urinary levels of PGI‐M or TxB₂. Urinary TxB₂ excretion was 15% lower after saline infusion (P = 0.03). These within‐treatment differences in prostanoid synthesis did not differ significantly between the treatments (anova ). Mean blood levels of CNIs were 486 μg/l for CsA and 12.8 μg/l for Tac. Clinically relevant doses of CsA and Tac induce acute differential changes in prostanoid levels in healthy human subjects. CsA suppresses COX‐2 activity, while Tac decreases platelet activity.     

Homotoxicological remedies versus desmopressin versus placebo in the treatment of enuresis: a randomised, double-blind, controlled trial

The aim of this trial was to compare the safety and efficacy of homotoxicological remedies versus placebo and versus desmopressin (dDAVP) in the treatment of monosymptomatic nocturnal enuresis (MNE). We conducted a randomised, double-blind, double-dummy, controlled trial in which 151 children with MNE were randomly assigned to receive oral homotoxicological remedies (n = 50), dDAVP (n = 50) or placebo (n = 51). The primary outcomes were: the reduction of wet nights per week after 3 months of therapy; the evaluation of the numbers and percentages of non-responders and responders; the number of children relapsing after initial response and the number of children attaining 14 consecutive dry nights during the treatment. The secondary outcome was the detection of adverse effects. Baseline clinical characteristics were similar in the three groups of patients. After the 3 months of therapy there was a significant difference between the three groups (P < 0.001) in the mean number of wet nights per week. The daily dose of dDAVP produced a statistically significant decrease (62.9%) in wet nights compared to placebo (2.4%) (P < 0.001) and compared to homotoxicological remedies (30.0%) (P < 0.001). There was a significant decrease in wet nights among the group treated with homotoxicological medications if compared with placebo (P < 0.001). The full response achieved with homotoxicological remedies (20%) was superior if compared with placebo (0%) (P < 0.001). Homotoxicology was superior to placebo (P < 0.001) with regard to the number of children attaining 14 consecutive dry nights during treatment. Our study demonstrates that homotoxicology is safe and effective when compared with placebo, even if it is significantly less effective than dDAVP in this clinical condition.     

The effects of perineural dexmedetomidine on the pharmacodynamic profile of femoral nerve block: a dose‐finding randomised,controlled, double‐blind study

This randomised, controlled, double‐blind study investigated the effects of different doses of perineural dexmedetomidine on the pharmacodynamic profile of femoral nerve block in patients undergoing arthroscopic knee surgery. Ultrasound‐guided femoral nerve block was performed before general anaesthesia using 25 ml of bupivacaine 0.5% combined with normal saline in the control group, and 25 μg, 50 μg or 75 μg of dexmedetomidine in three treatment groups (n = 15 for each group). All patients received a standard general anaesthetic and multimodal postoperative analgesic regimen. The use of the 50 μg and 75 μg dose levels of dexmedetomidine was associated with reduction of the onset time, extension of the duration of block, prolonged time to the first postoperative request for rescue analgesia, and reduced postoperative morphine requirements. The times to first request for postoperative analgesia were mean (SD) 10.8 (1.6) h in the control group and 11.0 (7.1), 21.8 (3.0) and 28.6 (10.0) in the 25 μg, 50 μg and 75 μg treatment groups, respectively. These times were significantly longer in the 50 μg and 75 μg treatment groups compared with the 25 μg (p < 0.0001) and control group (p < 0.0001). The total 24‐h postoperative morphine consumption was 7.6 (5.1) mg in the control group, and 6.5 (3.5), 3.9 (3.4), 1.8 (2.6) in the 25 μg, 50 μg and 75 μg treatment groups, respectively. Postoperative morphine consumption was significantly higher in the control group compared with the 50 μg (p = 0.045) and the 75 μg (p = 0.001) treatment groups. The best analgesic profile was achieved at the 75 μg dose, but this was associated with increased risk of hypotension.     

The analgesic efficiency of combined pregabalin and ketamine for total hip arthroplasty: a randomised,double‐blind,controlled study

Ketamine and pregabalin each provide postoperative analgesia, although the combination has yet to be evaluated. One hundred and forty‐two patients undergoing total hip arthroplasty were randomly assigned to receive ketamine alone, pregabalin alone, ketamine and pregabalin combined, or placebo. Pain scores at rest and on movement, morphine consumption, side‐effects, pressure pain thresholds and secondary hyperalgesia were evaluated. Mean (SD) total 48‐h morphine use was reduced in patients given ketamine alone (52 (22) mg) and pregabalin alone (44 (20) mg) compared with placebo (77 (36) mg) p < 0.001. Morphine use was further reduced in patients given both ketamine and pregabalin (38 (19) mg) with an interaction between ketamine and pregabalin (ANOVA factorial; p = 0.028). Secondary hyperalgesia was reduced by ketamine. There were no differences between groups in pain scores after surgery, pressure pain thresholds or side‐effects. The combination of pregabalin and ketamine has a small, beneficial clinical effect.     

Lung allocation score: the Eurotransplant model versus the revised US model – a cross‐sectional study

Both Eurotransplant (ET) and the US use the lung allocation score (LAS) to allocate donor lungs. In 2015, the US implemented a new algorithm for calculating the score while ET has fine‐tuned the original model using business rules. A comparison of both models in a contemporary patient cohort was performed. The rank positions and the correlation between both scores were calculated for all patients on the active waiting list in ET. On February 6th 2017, 581 patients were actively listed on the lung transplant waiting list. The median LAS values were 32.56 and 32.70 in ET and the US, respectively. The overall correlation coefficient between both scores was 0.71. Forty‐three per cent of the patients had a < 2 point change in their LAS. US LAS was more than two points lower for 41% and more than two points higher for 16% of the patients. Median ranks and the 90th percentiles for all diagnosis groups did not differ between both scores. Implementing the 2015 US LAS model would not significantly alter the current waiting list in ET.     

Intra‐operative protective mechanical ventilation in lung transplantation: a randomised,controlled trial

Primary graft dysfunction occurs in up to 25% of patients after lung transplantation. Contributing factors include ventilator‐induced lung injury, cardiopulmonary bypass, ischaemia‐reperfusion injury and excessive fluid administration. We evaluated the feasibility, safety and efficacy of an open‐lung protective ventilation strategy aimed at reducing ventilator‐induced lung injury. We enrolled adult patients scheduled to undergo bilateral sequential lung transplantation, and randomly assigned them to either a control group (volume‐controlled ventilation with 5 cmH₂O, positive end‐expiratory pressure, low tidal volumes (two‐lung ventilation 6 ml.kg^?1, one‐lung ventilation 4 ml.kg^?1)) or an alveolar recruitment group (regular step‐wise positive end‐expiratory pressure‐based alveolar recruitment manoeuvres, pressure‐controlled ventilation set at 16 cmH₂O with 10 cmH₂O positive end‐expiratory pressure). Ventilation strategies were commenced from reperfusion of the first lung allograft and continued for the duration of surgery. Regular PaO₂/F_IO₂ ratios were calculated and venous blood samples collected for inflammatory marker evaluation during the procedure and for the first 24 h of intensive care stay. The primary end‐point was the PaO₂/F_IO₂ ratio at 24 h after first lung reperfusion. Thirty adult patients were studied. The primary outcome was not different between groups (mean (SD) PaO₂/F_IO₂ ratio control group 340 (111) vs. alveolar recruitment group 404 (153); adjusted p = 0.26). Patients in the control group had poorer mean (SD) PaO₂/F_IO₂ ratios at the end of the surgical procedure and a longer median (IQR [range]) time to tracheal extubation compared with the alveolar recruitment group (308 (144) vs. 402 (154) (p = 0.03) and 18 (10–27 [5–468]) h vs. 15 (11–36 [5–115]) h (p = 0.01), respectively). An open‐lung protective ventilation strategy during surgery for lung transplantation is feasible, safe and achieves favourable ventilation parameters.