An assessment of the tolerability of the Cook staged extubation wire in patients with known or suspected difficult airways extubated in intensive care

The Cook staged extubation set (Cook Medical) has been developed to facilitate management of the difficult airway. A guidewire inserted before tracheal extubation provides access to the subglottic airway should re‐intubation be required. This prospective cohort study examines patients’ tolerance of the guidewire and its impact on clinical status around tracheal extubation in the intensive care unit. Vital signs, incidence of symptoms and patient tolerance of the wire were recorded. Twenty‐three patients were enrolled and 17 (73%) tolerated the wire for 4 h. Nasendoscopy was performed in 11 of these patients and revealed one wire was in the oesophagus. The most common symptom was a mild intermittent cough in 13 patients. There was no impact of the guidewire on nursing care in 16 patients, tolerable impact in five and severe impact necessitating removal of the wire in one patient.     

A randomised cross‐over comparison of the transverse and longitudinal techniques for ultrasound‐guided identification of the cricothyroid membrane in morbidly obese subjects

We compared the transverse and longitudinal approaches to ultrasound‐guided identification of the cricothyroid membrane, to determine which was faster and more successful. Forty‐two anaesthetists received a one‐hour structured training programme consisting of e‐learning, a lecture and hands‐on training, and then applied both techniques in a randomised, cross‐over sequence to obese females with body mass index 39.0 – 43.9 kg.m^?2. The mean (SD) time to identify the cricothyroid membrane was 24.0 (12.4) s using the transverse technique compared with 37.6 (17.9) s for the longitudinal technique (p = 0.0003). Successful identification of the cricothyroid membrane was achieved by 38 (90%) anaesthetists using either technique. All anaesthetists were successful in identifying the cricothyroid membrane with at least one of the techniques. We advocate the learning and application of these two techniques for identification of the cricothyroid membrane before starting anaesthesia in difficult patients, especially when anatomical landmarks are impalpable. Further use in emergency situations is feasible, if clinicians have experience and the ultrasound machine is readily available.     

The Airway App: exploring the role of smartphone technology to capture emergency front‐of‐neck airway experiences internationally

In this exploratory study we describe the utility of smartphone technology for anonymous retrospective observational data collection of emergency front‐of‐neck airway management. The medical community continues to debate the optimal technique for emergency front‐of‐neck airway management. Although individual clinicians infrequently perform this procedure, hundreds are performed annually worldwide. Ubiquitous smartphone technology and internet connectivity have created the opportunity to collect these data. We created the ‘Airway App’, a smartphone application to capture the experiences of healthcare providers involved in emergency front‐of‐neck airway procedures. In the first 18‐month period, 104 emergency front‐of‐neck airway management reports were received; 99 (95%) were internally valid and unique from 21 countries. Eighty‐one (82%) were performed by non‐surgeons and 63 (64%) were ‘cannot intubate, cannot oxygenate’ emergencies. Overall first‐attempt success varied by technique; 45 scalpel–bougie cricothyroidotomy (37 first‐attempt success), 25 surgical cricothyroidotomy (15 first‐attempt success), eight cannula cricothyroidotomy (five first‐attempt success), six wire‐guided cricothyroidotomy (three first‐attempt success) and 15 tracheostomy reports (11 first‐attempt success). The most commonly reported positive human factors were good communication, good teamwork and/or skilled personnel. The most commonly reported negative human factors were fixation on multiple tracheal intubation attempts, delay in initiating emergency front‐of‐neck airway and/or the failure to plan for failure. Due to the anonymous nature of reporting, reports are open to recollection bias and spurious reporting. We conclude collection of data using a smartphone application is feasible and has the potential to expand our knowledge of emergency front‐of‐neck airway management.     

Effect of palpable vs. impalpable cricothyroid membranes in a simulated emergency front‐of‐neck access scenario

The Difficult Airway Society 2015 guidelines recommend and describe in detail a surgical cricothyroidotomy technique for the can't intubate, can't oxygenate (CICO) scenario, but this can be technically challenging for anaesthetists with no surgical training. Following a structured training session, 104 anaesthetists took part individually in a simulated can't intubate, can't oxygenate event using simulation and airway models to evaluate how well they could perform these front‐of‐neck access techniques. Main outcomes measures were: ability to correctly perform the technical steps; procedural time; and success rate. Outcomes were compared between palpable and impalpable cricothyroid membrane scenarios. Anaesthetists’ technical abilities were good, as assessed by a video analysis checklist score. Mean (SD) procedural time was 44 (16) s and 65 (17) s for the palpable and impalpable cricothyroid membrane models, respectively (p ≤ 0.001). First‐pass tracheal tube placement was obtained in 103 out of the 104 palpable cricothyroidotomies and in 101 out of the 104 impalpable cricothyroidotomies (p = 0.31). We conclude that anaesthetists can be trained to perform surgical front‐of‐neck access to an acceptable level of competence and speed when assessed using a simulator.     

Choice of anaesthesia for category‐1 caesarean section in women with anticipated difficult tracheal intubation: the use of decision analysis

A predicted difficult airway is sometimes considered a contra‐indication to rapid sequence induction of general anaesthesia, even in an urgent case such as a category‐1 caesarean section for fetal distress. However, formally assessing the risk is difficult because of the rarity and urgency of such cases. We have used decision analysis to quantify the time taken to establish anaesthesia, and probability of failure, of three possible anaesthetic methods, based on a systematic review of the literature. We considered rapid sequence induction of general anaesthesia with videolaryngoscopy, awake fibreoptic intubation and rapid spinal anaesthesia. Our results show a shorter mean (95% CI) time to induction of 100 (87–114) s using rapid sequence induction compared with 9 (7–11) min for awake fibreoptic intubation (p < 0.0001) and 6.3 (5.4–7.2) min for spinal anaesthesia (p < 0.0001). We calculate the risk of ultimate failed airway control after rapid sequence induction to be 21 (0–53) per 100,000 cases, and postulate that some mothers may accept such a risk in order to reduce potential fetal harm from an extended time interval until delivery. Although rapid sequence induction may not be the anaesthetic technique of choice for all cases in the circumstance of a category‐1 caesarean section for fetal distress with a predicted difficult airway, we suggest that it is an acceptable option.     

A cadaver study comparing three fibreoptic‐assisted techniques for converting a supraglottic airway to a cuffed tracheal tube

After rescuing an airway with a supraglottic airway device, a method to convert it to a cuffed tracheal tube is often needed. The best method to do this has never been directly studied. We compared three techniques for conversion of a standard LMA^® Unique airway to a cuffed endotracheal tube using a fibrescope. The primary endpoint was time to intubation, with secondary endpoints of success rate, perceived difficulty and preferred technique. We also investigated the relationship between level of training and prior training and experience with the techniques on the primary outcome. The mean (95% CI) time to intubation using a direct tracheal tube technique of 37 (31–42) s was significantly shorter than either the Aintree intubation catheter technique at 70 (60–80) s, or a guidewire technique at 126 (110–141) s (p < 0.001). Most (13/24) participants rated the tracheal tube as their preferred technique, while 11/24 preferred the Aintree technique. In terms of perceived difficulty, 23/24, 21/24 and 9/24 participants rated the tracheal tube technique, Aintree technique and guidewire technique, respectively, as either very easy or easy. There was no relationship between prior training, prior experience or level of training on time to completion of any of the techniques. We conclude the tracheal tube and Aintree techniques both provide a rapid and easy method for conversion of a supraglottic airway device to a cuffed tracheal tube. The guidewire technique cannot be recommended.     

The impact of didactic read‐aloud action cards on the performance of cannula cricothyroidotomy in a simulated ‘can't intubate can't oxygenate’ scenario

Significant benefits have been demonstrated with the use of peri‐operative checklists. We assessed whether a read‐aloud didactic action card would improve performance of cannula cricothyroidotomy in a simulated ‘can't intubate, can't oxygenate’ scenario. A 17‐step action card was devised by an expert panel. Participants in their first 4 years of anaesthetic training were randomly assigned into ‘no‐card’ or ‘card’ groups. Scenarios were video‐recorded for analysis. Fifty‐three participants (27 no‐card and 26 card) completed the scenario. The number of steps omitted was mean (SD) 6.7 (2.0) in the no‐card group vs. 0.3 (0.5); p < 0.001 in the card group, but the no‐card group was faster to oxygenation by mean (95% CI) 35.4 (6.6–64.2) s. The Kappa statistic was 0.84 (0.73–0.95). Our study demonstrated that action cards are beneficial in achieving successful front‐of‐neck access using a cannula cricothyroidotomy technique. Further investigation is required to determine this tool's effectiveness in other front‐of‐neck access situations, and its role in teaching or clinical management.     

Sodium‐glucose co‐transporter type‐2 inhibitors: pharmacology and peri‐operative considerations

Sodium‐glucose co‐transporter 2 (SGLT2) inhibitors are an emerging class of oral hypoglycaemic agents with therapeutic benefits beyond better glycaemic control. A major concern of the sodium‐glucose co‐transporter 2 inhibitors is their propensity to cause euglycaemic ketoacidosis in the peri‐operative period and the potential for this critical diagnosis to be delayed or missed entirely. This review attempts to collate the case reports of sodium‐glucose co‐transporter 2 inhibitor ketoacidosis associated with surgery to highlight and put a perspective on this peri‐operative issue. Preventive strategies and the management of the ketoacidosis are discussed.     

Bedside tests for predicting difficult airways: an abridged Cochrane diagnostic test accuracy systematic review

Although bedside screening tests are routinely used to identify people at high risk of having a difficult airway, their clinical utility is unclear. We estimated the diagnostic accuracy of commonly used bedside examination tests for assessing the airway in adult patients without apparent anatomical abnormalities scheduled to undergo general anaesthesia. We searched for studies that reported our pre-specified bedside index screening tests against a reference standard, published in any language, from date of inception to 16 December 2016, in seven bibliographic databases. We included 133 studies (127 cohort type and 6 case–control) involving 844,206 participants. Overall, their methodological quality (according to QUADAS-2, a standard tool for assessing quality of diagnostic accuracy studies) was moderate to high. Our pre-specified tests were: the Mallampati test (6 studies); modified Mallampati test (105 studies); Wilson risk score (6 studies); thyromental distance (52 studies); sternomental distance (18 studies); mouth opening test (34 studies); and the upper lip bite test (30 studies). Difficult facemask ventilation, difficult laryngoscopy, difficult intubation and failed intubation were the reference standards in seven, 92, 50 and two studies, respectively. Across all reference standards, we found all index tests had relatively low sensitivities, with high variability, but specificities were consistently and markedly higher than sensitivities. For difficult laryngoscopy, the sensitivity and specificity (95%CI) of the upper lip bite test were 0.67 (0.45–0.83) and 0.92 (0.86–0.95), respectively; upper lip bite test sensitivity (95%CI) was significantly higher than that for the mouth opening test (0.22, 0.13–0.33; p < 0.001). For difficult tracheal intubation, the modified Mallampati test had a significantly higher sensitivity (95%CI) at 0.51 (0.40–0.61) compared with mouth opening (0.27, 0.16–0.41; p < 0.001) and thyromental distance (0.24, 0.12–0.43; p < 0.001). Although the upper lip bite test showed the most favourable diagnostic test accuracy properties, none of the common bedside screening tests is well suited for detecting unanticipated difficult airways, as many of them are missed.     

A survey of UK peri‐operative medicine: pre‐operative care

The majority of UK hospitals now have a Local Lead for Peri‐operative Medicine (n = 115). They were asked to take part in an online survey to identify provision and practice of pre‐operative assessment and optimisation in the UK. We received 86 completed questionnaires (response rate 75%). Our results demonstrate strengths in provision of shared decision‐making clinics. Fifty‐seven (65%, 95%CI 55.8–75.4%) had clinics for high‐risk surgical patients. However, 80 (93%, 70.2–87.2%) expressed a desire for support and training in shared decision‐making. We asked about management of pre‐operative anaemia, and identified that 69 (80%, 71.5–88.1%) had a screening process for anaemia, with 72% and 68% having access to oral and intravenous iron therapy, respectively. A need for peri‐operative support in managing frailty and cognitive impairment was identified, as few (24%, 6.5–34.5%) respondents indicated that they had access to specific interventions. Respondents were asked to rank their ‘top five’ priority topics in Peri‐operative Medicine from a list of 22. These were: shared decision‐making; peri‐operative team development; frailty screening and its management; postoperative morbidity prediction; and primary care collaboration. We found variation in practice across the UK, and propose to further explore this variation by examining barriers and facilitators to improvement, and highlighting examples of good practice.     

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.     

Risk factors for multidrug‐resistant organisms among deceased organ donors

Donor infection or colonization with a multidrug‐resistant organism (MDRO) affects organ utilization and recipient antibiotic management. Approaches to identifying donors at risk of carrying MDROs are unknown. We sought to determine the risk factors for MDROs among transplant donors. A multicenter retrospective cohort study was conducted at four transplant centers between 2015 and 2016. All deceased donors who donated at least one organ were included. Cultures obtained during the donor's terminal hospitalization and organ procurement were evaluated. The primary outcome was isolation of an MDRO on culture. Multivariable Cox regression was used to determine risk factors associated with time to donor MDRO. Of 440 total donors, 64 (15%) donors grew an MDRO on culture. Predictors of an MDRO on donor culture included hepatitis C viremia (hazard ratio [HR] 4.09, 95% confidence interval [CI] 1.71‐9.78, P = .002), need for dialysis (HR 4.59, 95% CI 1.09‐19.21, P = .037), prior hematopoietic cell transplant (HR 7.57, 95% CI 1.03‐55.75, P = .047), and exposure to antibiotics with a narrow gram‐negative spectrum (HR 1.13, 95% CI 1.00‐1.27, P = .045). This is the first study to determine risk factors for MDROs among deceased donors and will be important for risk stratifying potential donors and informing transplant recipient prophylaxis.     

Risk factors for late‐onset hypogonadism

The European Male Aging Study (EMAS) has recently defined strict diagnostic criteria for late‐onset hypogonadism (LOH) including the levels of serum total testosterone (TT), free testosterone (FT) and three sexual symptoms. However, there is no report on risk factors for LOH using these criteria. In this study, we investigated risk factors for LOH based on these criteria. We recruited 277 men (aged 36‐80 years) who completed both a health check‐up and two questionnaires (a health and lifestyle questionnaire, and a sexual function questionnaire). Data on parameters, such as systolic blood pressure (SBP), glucose, triglyceride (TG) and high‐density lipoprotein (HDL), were obtained from medical records of the hospital in Shantou. TT and sex hormone‐binding globulin (SHBG) were measured by chemiluminescent immunoassay, and FT was calculated. TT, FT, age, waist circumference, SBP and glucose showed significant differences between LOH‐positive and LOH‐negative individuals. Univariate regression analyses showed that age, waist circumference, SBP, glucose and health status were risk factors for LOH. Pearson's correlation analysis revealed that TT was inversely correlated with waist circumference, glucose and SBP, and FT was inversely correlated with age, SBP and health status. In conclusion, age, waist circumference, SBP, glucose and health status were risk factors for LOH.     

Adaptations in pediatric anesthesia care and airway management in the resource‐poor setting

The need for safe and quality pediatric anesthesia care in low‐ and middle‐income countries (LMICs) is huge. An estimated 1.7 billion children do not have access to surgical care, and the majority are in LMICs. In addition, most LMICs do not have the requisite surgical workforce including anesthesia providers. Surgery is usually performed at three levels of facilities: district, provincial, and national referral hospitals. Unfortunately, the manpower, equipment, and other resources available to provide surgical care for children vary greatly at the different level facilities. The majority of district level hospitals are staffed solely by non‐physician anesthesia providers with variable training and little support to manage complicated pediatric patients. Airway and respiratory complications are known to account for a large portion of pediatric perioperative complications. Management of the difficult pediatric airway pathology is a challenge for anesthesia providers regardless of setting. However, in the low‐resource setting poor infrastructure, lack of transportation systems, and crippled referral systems lead to late presentation. There is often a lack of pediatric‐sized anesthesia equipment and resources, making management of the local pathology even more challenging. Efforts are being made to offer these providers additional training in pediatric anesthesia skills that incorporate low‐fidelity simulation. Out of necessity, anesthesia providers in this setting learn to be resourceful in order to manage complex pathologies with fewer, less ideal resources while still providing a safe anesthetic.     

Diagnostic point‐of‐care ultrasound: applications in obstetric anaesthetic management

Complications during pregnancy are not frequent, but may occur abruptly. Point‐of‐care ultrasound is a non‐invasive, non‐ionising diagnostic tool that is available at the bed‐side when complications occur. This review covers the use of ultrasound in various clinical situations. Gastric ultrasound can identify stomach contents that put the woman at risk for pulmonary aspiration. In the future, this tool will probably be used routinely before induction of anaesthesia to determine the presence of stomach contents above a particular risk threshold. Difficult tracheal intubation, and the potential for ‘can't intubate, can't oxygenate’, is more frequent in pregnant women. Point‐of‐care ultrasound of the airway allows accurate identification of the cricothyroid membrane, permitting rapid and safer establishment of front‐of‐neck airway access. Combined cardiac and lung ultrasound can determine the potential risk:benefit of fluid administration in the pregnant patient. Such prediction is of critical importance, given the tendency of pregnant women to develop pulmonary oedema. Combined echocardiography and lung ultrasound can be combined with ultrasound of the leg veins to differentiate between the various causes of acute respiratory failure, and guide treatment in this situation. Finally, as shown in the general population, multi‐organ point‐of‐care ultrasound allows early diagnosis of the main causes of circulatory failure and cardiac arrest at the bed‐side. As the importance of point‐of‐care ultrasound in critical patients is increasingly recognised, it is emerging as an important tool in the therapeutic armoury of obstetric anaesthetists.     

International consensus statement on the peri‐operative management of anaemia and iron deficiency

Despite current recommendations on the management of pre‐operative anaemia, there is no pragmatic guidance for the diagnosis and management of anaemia and iron deficiency in surgical patients. A number of experienced researchers and clinicians took part in an expert workshop and developed the following consensus statement. After presentation of our own research data and local policies and procedures, appropriate relevant literature was reviewed and discussed. We developed a series of best‐practice and evidence‐based statements to advise on patient care with respect to anaemia and iron deficiency in the peri‐operative period. These statements include: a diagnostic approach for anaemia and iron deficiency in surgical patients; identification of patients appropriate for treatment; and advice on practical management and follow‐up. We urge anaesthetists and peri‐operative physicians to embrace these recommendations, and hospital administrators to enable implementation of these concepts by allocating adequate resources.