Supraglottic Airway Devices: Present State and Outlook for 2050.

Correct placement of supraglottic airway devices (SGDs) is crucial for patient safety and of prime concern of anesthesiologists who want to provide effective and efficient airway management to their patients undergoing surgery or procedures requiring anesthesia care. In the majority of cases, blind insertion of SGDs results in less-than-optimal anatomical and functional positioning of the airway devices. Malpositioning can cause clinical malfunction and result in interference with gas exchange, loss-of-airway, gastric inflation, and aspiration of gastric contents. A close match is needed between the shape and profile of SGDs and the laryngeal inlet. An adequate first seal (with the respiratory tract) and a good fit at the second seal of the distal cuff and the gastrointestinal tract are most desirable. Vision-guided insertion techniques are ideal and should be the way forward. This article recommends the use of third-generation vision-incorporated-video SGDs, which allow for direct visualization of the insertion process, corrective maneuvers, and, when necessary, insertion of a nasogastric tube (NGT) and/or endotracheal tube (ETT) intubation. A videoscope embedded within the SGD allows a visual check of the glottis opening and position of the epiglottis. This design affords the benefit of confirming and/or correcting a SGD's position in the midline and rotation in the sagittal plane. The first clinically available video laryngeal mask airways (VLMAs) and multiple prototypes are being tested and used in anesthesia. Existing VLMAs are still not perfect, and further improvements are recommended. Additional modifications in multicamera technology, to obtain a panoramic view of the SGD sitting correctly in the hypopharynx and to prove that correct sizes have been used, are in the process of production. Ultimately, any device inserted orally-SGD, ETT, NGT, temperature probe, transesophageal scope, neural integrity monitor (NIM) tubes-could benefit from correct vision-guided positioning. VLMAs also allow for automatic recording, which can be documented in clinical records of patients, and could be valuable during teaching and research, with potential value in case of legal defence (with an airway incident). If difficulties occur with the airway, documentation in the patient's file may help future anesthesiologists to better understand the real-time problems. Both manufacturers and designers of SGDs may learn from optimally positioned SGDs to improve the design of these airway devices.

Incidence and Factors Related to Prolonged Postoperative Cognitive Decline (POCD) in Elderly Patients Following Surgery and Anaesthesia: A Systematic Review.

Aim: The aim of this systematic review is to explore the current literature to provide evidence regarding the incidence and risk factors of prolonged POCD in elderly patients following cardiac and non-cardiac surgical interventions. Methods: The PubMed and Google Scholar databases were searched using appropriate keywords and search engines for adequate evidence from studies meeting the inclusion criteria so as to reveal the end-point, which was the presence of prolonged POCD in elderly patients following surgery and anaesthesia. The incidence of POCD at different time intervals and the variables predicting the occurrence of POCD were analysed. Results: The results of 23 articles covering 5077 patients (3694 non cardiac and 1383 cardiac surgeries) were carefully analysed. POCD occurs from the first postoperative day and lasts for potentially long periods. The incidence of POCD in this review ranged from 2.2% to 35.7%. More specifically, it ranged from 2.2% to 31.5% in non-cardiac surgeries and 11.8% to 35.7% in patients who had undergone cardiac surgeries. Some of the independent risk factors (predictors) for the development of POCD were advanced age, high concentration of neuroinflammatory mediators detectable in plasma, low SpO2, longer anaesthetic and surgical duration, and depth of anaesthesia. Conclusion: This review can only provide limited evidence of prolonged POCD (more than a year) and further research that involves better study designs, larger samples, involving longer follow-up, and at different sites (multicentre) is highly advised. This in turn may help researchers and clinicians to discover the actual causes and risk factors and develop appropriate preventive and treatment protocols to tackle POCD in the ageing surgical population.

Anesthesia and perioperative pain relief in the frail elderly patient.

Demand for anesthesia and analgesia for the frail elderly is continuously increasing as the likelihood of encountering very elderly, very vulnerable, and very compromised patients has, ever so subtly, increased over the last three decades. The anesthesiologist has, increasingly, been obliged to offer professional services to frail patients. Fortunately, there has been a dramatic improvement in medications, methods of drug delivery, critical monitoring, and anesthesia techniques. Specific methodologies peculiar to the frail are now taught and practiced across all anesthesia subspecialties. However, administering anesthesia for the frail elderly is vastly different to giving an anesthetic to the older patient. Frail patients are increasingly cared for in specialized units-geriatric intensive therapy units, post-acute care services, palliative, hospices, and supportive care and aged care facilities. Several medications (e.g., morphine-sparing analgesics) more suited to the frail have become universally available in most centers worldwide so that best-practice, evidence-based anesthesia combinations of drugs and techniques are now increasingly employed. Every anesthetic and pain management techniques in the frail elderly patient are going to be discussed in this review.

Plasma and Interstitial Fluid Pharmacokinetics of Prophylactic Cefazolin in Elective Bariatric Surgery Patients.

Guidelines for surgical prophylactic dosing of cefazolin in bariatric surgery vary in terms of recommended dose. This study aimed to describe the plasma and interstitial fluid (ISF) cefazolin pharmacokinetics in patients undergoing bariatric surgery and to determine an optimum dosing regimen. Abdominal subcutaneous ISF concentrations (measured using microdialysis) and plasma samples were collected at regular time points after administration of cefazolin 2 g intravenously. Total and unbound cefazolin concentrations were assayed and then modeled using Pmetrics. Monte Carlo dosing simulations (n = 5,000) were used to define cefazolin dosing regimens able to achieve a fractional target attainment (FTA) of >95% in the ISF suitable for the MIC for Staphylococcus aureus in isolates of ≤2 mg · L-1 and for a surgical duration of 4 h. Fourteen patients were included, with a mean (standard deviation [SD]) bodyweight of 148 (35) kg and body mass index (BMI) of 48 kg · m-2. Cefazolin protein binding ranged from 14 to 36% with variable penetration into ISF of 58% ± 56%. Cefazolin was best described as a four-compartment model including nonlinear protein binding. The mean central volume of distribution in the final model was 18.2 (SD 3.31) L, and the mean clearance was 32.4 (SD 20.2) L · h-1. A standard 2-g dose achieved an FTA of >95% for all patients with BMIs ranging from 36 to 69 kg · m-2. A 2-g prophylactic cefazolin dose achieves appropriate unbound plasma and ISF concentrations in obese and morbidly obese bariatric surgery patients.

Obesity, metabolic syndrome, and inflammation: An update for anaesthetists caring for patients with obesity.

Our understanding of chronic inflammation in obesity is evolving. Suggested mechanisms include hypoxia of adipose tissue and a subsequent increase in circulating cytokines. It is now known that adipose tissue, far from being an inert tissue, produces and secretes multiple peptides that influence inflammation and metabolism, including substrates of the renin-angiotensin-aldosterone system (RAAS). RAAS blocking antihypertensive medication and cholesterol-lowering agents are now being evaluated for their metabolic and inflammation-modulating effects. Surgery also has pro-inflammatory effects, which may be exacerbated in patients with obesity. This narrative review will summarise the recent literature surrounding obesity, metabolic syndrome, inflammation, and interplay with the RAAS, with evidence-based recommendations for the optimisation of patients with obesity, prior to surgery and anaesthesia.

Modified Retrograde Nasal Intubation: A New Airway Technique and Devices.

Nasotracheal intubation remains an underused but invaluable technique for securely managing the airway during oral and maxillofacial surgery. In this article, we present a modified clinical technique that allows for the potential introduction into clinical practice of 2 new airway devices: a nasal laryngeal mask airway and an interchangeable oral/nasal endotracheal tube. We hypothesize that with the use of proper techniques, these devices can add new and safer alternatives for securing an airway by the nasal route. The advantage of this novel technique is that the airway is secured by the oral route prior to performing a modified retrograde nasal intubation, eliminating the danger of profuse epistaxis precipitating a "cannot intubate, cannot ventilate" scenario. In addition, the design and materials used in the components of the devices may minimize trauma. The authors aim to inform clinicians about the indications, physical characteristics, and insertion/removal techniques related to these new devices.

Prophylactic Cefazolin Dosing in Women With Body Mass Index >35 kg·m-2 Undergoing Cesarean Delivery: A Pharmacokinetic Study of Plasma and Interstitial Fluid.

BACKGROUND: Obesity is a risk factor for surgical site infection after cesarean delivery. There is inadequate pharmacokinetic data available regarding prophylactic cefazolin dosing in obese pregnant women. We aimed to describe the plasma and interstitial fluid (ISF) pharmacokinetics of cefazolin in obese women undergoing elective cesarean delivery and use dosing simulations to predict optimal dosing regimens. METHODS: Eligible women were scheduled for elective cesarean delivery at term, with a body mass index (BMI) of >35 kg·m. Plasma and ISF samples were collected following 2 g of intravenous cefazolin. Concentrations were determined using liquid chromatography-mass spectrometry. Population pharmacokinetic modeling and Monte Carlo dosing simulations were performed using Pmetrics. Total and unbound cefazolin concentrations in plasma and ISF were compared with the minimum inhibitory concentration at which 90% of isolates are inhibited (MIC90) of cefazolin for Staphylococcus aureus, 2 mg·L. The fractional target attainment (FTA) of dosing regimens to achieve a pre-established target of 95% unbound ISF concentrations >2 mg·L throughout a 3-hour duration of the surgery was calculated. RESULTS: The 12 women recruited had a median (interquartile range [IQR]) BMI of 41.5 (39.7-46.6) kg·m and a median (IQR) gestation of 38.7 weeks (37.9-39.0). For each timepoint up to 180 minutes, the median across subjects of total and unbound plasma concentration of cefazolin remained above 2 mg·L. The minimum observed total plasma concentration was 31.7 mg·L and plasma unbound concentration was 7.7 mg·L (observed in the same participant). For each timepoint up to 150 minutes, the median across subjects of unbound ISF concentrations remained above 2 mg·L. The minimum observed unbound ISF concentration was 0.7 mg·L (observed in 1 participant). In 2 participants, the ISF concentration of cefazolin was not maintained above 2 mg·L. The mean (± standard error [SE]) penetration of cefazolin (calculated as area under the concentration-time curve for the unbound fraction of drug [fAUC]tissue/fAUCplasma) into the ISF was 0.884 ± 1.11. Simulations demonstrated that FTA >95% was achieved in patients weighing 90-150 kg by an initial 2 g dose with redosing of 2 g at 2 hours. FTA was improved to >99% when an initial 3 g dose was repeated at 2 hours. CONCLUSIONS: To maintain adequate ISF antibiotic concentrations in obese pregnant women, our results suggest that redosing of cefazolin may be required. When wound closure has not occurred within 2 hours, redosing is suggested, following either a 2 or 3 g initial bolus. These preliminary results require validation in a larger population.

A prospective randomized comparison of airway seal using the novel vision-guided insertion of LMA-Supreme® and LMA-Protector®.

The laryngeal mask airways supreme (LMA-Supreme™) and protector (LMA-Protector™) are generally placed blindly, often resulting in a less than optimal position and vision-guided placement has been recommended. This prospective, randomized controlled study compared the efficacy of airway seal by measuring the oropharyngeal leak pressure in 100 surgical patients who underwent a variety of non-thoracic surgery under general anaesthesia, suitable with a supraglottic airway device. Patients were allocated to either the LMA-Supreme (n = 50) or LMA-Protector (n = 50) group. All insertions were performed under vision of a videolaryngoscope using an 'insert-detect-correct-as-you-go' technique with standardized corrective measures. Our primary endpoint, mean oropharyngeal leak pressure, was significantly higher in the LMA-Protector (31.7 ± 2.9 cm H2O) compared to the LMA-Supreme (27.7 ± 3.5 cm H2O) group (mean difference 4.0 cm H2O, 95% confidence interval (CI) 2.7-5.3 cm H2O, p < 0.001) after achieving a near-optimal fibreoptic position in the LMA-Protector (94%) and LMA-Supreme (96%) groups. No statistically significant differences were shown for secondary outcomes of alignment, number of insertion attempts and malpositions, and final anatomical position as scored by fibreoptic evaluation. Corrective manoeuvres were required in virtually all patients to obtain a correct anatomically positioned LMA. Position outcomes of the two devices were similar except for the proportion of procedures with folds in the proximal cuff (90% LMA-Supreme vs. 2% LMA-Protector, p < 0.001), the need for intracuff pressure adjustments (80% LMA-Supreme vs. 48% LMA-Protector, p = 0.001) and size correction (18% LMA-Supreme vs. 4% LMA-Protector, p = 0.025). In conclusion, a higher oropharyngeal leak pressure can be achieved with LMA-Protector compared to LMA-Supreme with optimal anatomical position when insertion is vision-guided.

Macintosh Blade Videolaryngoscopy Combined With Rigid Bonfils Intubation Endoscope Offers a Suitable Alternative for Patients With Difficult Airways.

BACKGROUND: In the armamentarium of an anesthesiologist, videolaryngoscopy is a valuable addition to secure the airway. However, when the videolaryngoscope (VLS) offers no solution, few options remain. Earlier, we presented an intubation technique combining Macintosh blade VLS and Bonfils intubation endoscope (BIE) for a patient with a history of very difficult intubation. In the present study, we evaluated this technique to establish whether it is a valuable alternative. METHODS: In this single-blinded nonrandomized study, 38 patients with a history of difficult intubation or 1 or more predictors of difficult intubation, scoring a Cormack & Lehane (C&L) grade III or IV using Macintosh blade VLS, were included. Patients were intubated combining the VLS with the BIE. The C&L grade was scored 3 times during (1) direct laryngoscopy; (2) indirect videolaryngoscopy; and (3) using the combined technique (VLS + BIE). Afterward, 2 blinded anesthesiologists assessed the C&L grade using the pictures taken during the procedure. RESULTS: Data of 38 patients were analyzed. An improvement of the C&L grade with the combined technique occurred in 33 of 38 patients (86.8%; 95% confidence interval, 71.9%-95.6%). Reviewer 1 reported an improvement of the C&L grade with the combined technique in 37 of 38 patients. Reviewer 2 reported improvement in 33 and deterioration in 2 of the patients. No complications occurred. CONCLUSIONS: The combined use of a VLS with Macintosh blade and BIE gives the anesthesiologist a valuable alternative intubation option in patients with extremely difficult airways.

Regional anesthesia and analgesia in cancer care: is it time to break the bad news?

PURPOSE OF REVIEW: There is ongoing controversy regarding the tumor-protective effects of regional anesthesia in patients undergoing cancer surgery. Evidence of up-to-date systematic reviews will be presented alongside recent updates on the effects of opioids and local anesthetics. RECENT FINDINGS: In recent years, the literature regarding the effects of regional anesthesia techniques on cancer recurrence has raised many unanswered questions. Ongoing randomized controlled trials may not be able to shed light on the controversial discussion regarding the tumor protective effects of regional anesthesia because the expected effect size and event rate in those studies may be overstated.Recent more refined animal data, provides no evidence to suggest that opioids promote cancer recurrence or facilitate the development of metastatic disease.In addition, local anesthetics have promising preclinical anticarcinogenic effects that extend beyond their voltage-gated sodium channel blocking properties and could be of therapeutic value. SUMMARY: Cancer recurrence in patients undergoing surgery remains a global burden. Current evidence suggests that regional techniques, opioid analgesia and local anesthetics in onco-anesthesia may require a tailored individual approach due to the phenotypic and genotypic heterogeneity within and between different tumors. The authors surmise that future or ongoing randomized controlled trials regarding regional anesthesia techniques and cancer outcome may not be able to reproduce clear results, as it will be challenging to prove the efficacy of one single intervention (e.g. regional anesthesia) in an otherwise complex multifactorial perioperative oncological setting.

Perioperative Anesthesia Care and Tumor Progression.

This narrative review discusses the most recent up-to-date findings focused on the currently available "best clinical practice" regarding perioperative anesthesia care bundle factors and their effect on tumor progression. The main objective is to critically appraise the current literature on local anesthetics, regional outcome studies, opioids, and nonsteroidal anti-inflammatory drugs (NSAIDs) and their ability to decrease recurrence in patients undergoing cancer surgery. A brief discussion of additional topical perioperative factors relevant to the anesthesiologist including volatile and intravenous anesthetics, perioperative stress and anxiety, nutrition, and immune stimulation is included. The results of several recently published systematic reviews looking at the association between cancer recurrences and regional anesthesia have yielded inconclusive data and provide insufficient evidence regarding a definitive benefit of regional anesthesia. Basic science data suggests an anti tumor effect induced by local anesthetics. New refined animal models show that opioids can safely be used for perioperative pain management. Preliminary evidence suggests that NSAIDs should be an essential part of multimodal analgesia. Volatile anesthetics have been shown to increase tumor formation, whereas preclinical and emerging clinical data from propofol indicate tumor protective qualities. The perioperative period in the cancer patient represents a unique environment where surgically mediated stress response leads to immune suppression. Regional anesthesia techniques when indicated in combination with multimodal analgesia that include NSAIDs, opioids, and local anesthetics to prevent the pathophysiologic effects of pain and neuroendocrine stress response should be viewed as an essential part of balanced anesthesia.

Comparison of the diameter, cross-sectional area, and position of the left and right internal jugular vein and carotid artery in adults using ultrasound.

STUDY OBJECTIVE: Central venous access is indicated for transduction of central venous pressure and the administration of inotropes in the perioperative period. The right internal jugular vein (RIJV) is cannulated preferentially over the left internal jugular vein (LIJV). Cannulation of the LIJV is associated with a higher complication rate and a perceived increased level of difficulty when compared with cannulation of the RIJV. Possible explanations for the higher complication rate include a smaller diameter and more anterior position relative to the corresponding carotid artery (CA) of the LIJV compared with the RIJV. In this study, the RIJV and LIJV were examined in mechanically ventilated patients to determine the validity of these possible explanations. DESIGN: A prospective, nonrandomized cohort study. SETTING: The operating room of a major teaching hospital. PATIENTS: One hundred fifty-one patients scheduled for elective heart surgery. INTERVENTION: Ultrasound examination of the RIJV and LIJV at the level of the cricoid cartilage with a 12-MHz linear transducer in 151 anesthetized, mechanically ventilated patients in the Trendelenburg position. MEASUREMENTS AND RESULTS: In 72% of patients, the RIJV was dominant over the LIJV. The diameter and cross-sectional area of the RIJV was larger than the LIJV (P < .001). An anterior position of the LIJV in relation to the left CA was detected more often when compared with the RIJV and right CA (15.1% vs 5.4%, P = .01). CONCLUSION: This study confirms the smaller diameter and increased frequency of anterior positioning relative to the corresponding CA of the LIJV when compared with the RIJV. This validates them as possible explanations for the higher complication rate of LIJV cannulation compared with RIJV cannulation.

A novel method of intubation and orogastric tube insertion using a C-MAC-D-blade videolaryngoscope-bougie technique.

INTRODUCTION: Expertise in airway management is a fundamental aspect of anesthesia practice. Fortunately 'can't intubate, can't ventilate' scenarios are extremely rare. In particular, patients with tumors on the right side of the oropharynx and larynx can be very problematic to intubate. METHODS: We present an alternative intubation technique, whereby a C-MAC D-blade videolaryngoscope is loaded with a Frova catheter in the narrow, curving channel within the blade's infero-posterior aspect on the left side of the blade. This technique can be a successful alternative in patients with difficult airways. RESULTS: The proposed technique was successfully demonstrated in a case whereby a 47-year old male with premetrics of a difficult airway, presented with a large mass in the right supraglottis and hypopharynx with through-and-through thyroid cartilage infiltration, obstructing completely the view of the glottis with direct laryngoscopy. The referral hospital considered the patient unintubatable and sent the patient to our academic center for treatment. Endotracheal intubation with the new technique was successful at the first attempt. CONCLUSIONS: The C-MAC D-Blade videolaryngoscope-bougie technique provides an alternative method to intubate patients with difficult airways, even in exceptional situations such as in patients with a large right-sided oropharynx-larynx tumor.

Impact of postoperative renal replacement therapy on long-term outcome after cardiac surgery increases with age.

BACKGROUND AND AIM OF THE STUDY: In the present study, we investigated the survival of patients who received postoperative renal replacement therapy (RRT) after cardiac surgery. We specifically focused on factors predicting long-term outcome in elderly patients. METHODS: Data of all patients that received unintentional renal replacement therapy following cardiac surgery between 2004 and 2010 were analyzed. Logistic- and Cox regression analyses were performed to detect the predictors of early and late mortality, respectively. RESULTS: During the study period, 11,899 patients underwent cardiac surgery in our center. Post-operative RRT was performed in 138 patients (1.2%). In this group of patients, 30-day mortality included 72 patients (52%) and the total overall mortality included 107 patients (77.5%). Regression analyses revealed that age predicted 30-day mortality (odds ratio = 1.08 [1.03 to 1.12]) as well as late mortality (odds ratio = 1.05 [1.02 to 1.07]. CONCLUSIONS: Patients requiring RRT after cardiac surgery have a poor prognosis with a high mortality. Older age predicted both 30-day and late mortality in these patients.