Supraglottic airway devices in the ambulatory setting

Safety, Efficacy, and Ease of Insertion of Gnana Laryngeal Airway (GLA-4): A Prospective Clinical Study Utilizing the Unique Laryngeal Mask Airway With a Suction Tubing

INTRODUCTION

Utilizing laryngeal mask airways to maintain patients' airways is advantageous because it enables the anesthesiologist to keep the patient spontaneously inhaling and is less traumatic to the airway than intubation. Newer designs such as the Gnana laryngeal mask airway design permit real-time suctioning while the mask is on a patient.

METHODS

This is a prospective observational study of the efficacy of Gnana laryngeal airway 4 (GLA-4) in 50 patients undergoing colonoscopy. Induction and maintenance of anesthesia were provided with propofol; GLA-4 was applied to secure the airway; and correct placement was verified.

RESULTS

Fifty patients were included in the study (44% female, 56% male, mean age: 56.5 years, mean BMI: 33.3). Twelve patients were assigned American Society of Anesthesiologists (ASA) class 2, and 38 were assigned ASA class 3. The first attempt of GLA-4 insertion was successful in 47 patients, and two attempts were required for the successful placement of the GLA-4 in two patients. The successful placement was not achieved in one patient. The average time to successful insertion was 27.1 ± 3.9s. The average volume of oropharyngeal secretions suctioned through the suction catheter was 9.96 ± 2.31 mL. No intraoperative or postoperative complications occurred in the 50 patients. There were no reports of sore throat, hoarseness, dysphagia, or cough immediately postop.

CONCLUSION

GLA-4 can be inserted safely with adequate periglottic occlusion. This laryngeal mask is unique and desirable due to its ability to evacuate oropharyngeal secretions while in place to prevent laryngospasm. To establish the role of GLA-4 in broader clinical situations, additional clinical trials and studies are required.

Airway physical examination tests for detection of difficult airway management in apparently normal adult patients

BACKGROUND

The unanticipated difficult airway is a potentially life-threatening event during anaesthesia or acute conditions. An unsuccessfully managed upper airway is associated with serious morbidity and mortality. Several bedside screening tests are used in clinical practice to identify those at high risk of difficult airway. Their accuracy and benefit however, remains unclear.

OBJECTIVES

The objective of this review was to characterize and compare the diagnostic accuracy of the Mallampati classification and other commonly used airway examination tests for assessing the physical status of the airway in adult patients with no apparent anatomical airway abnormalities. We performed this individually for each of the four descriptors of the difficult airway: difficult face mask ventilation, difficult laryngoscopy, difficult tracheal intubation, and failed intubation.

SEARCH METHODS

We searched major electronic databases including CENTRAL, MEDLINE, Embase, ISI Web of Science, CINAHL, as well as regional, subject specific, and dissertation and theses databases from inception to 16 December 2016, without language restrictions. In addition, we searched the Science Citation Index and checked the references of all the relevant studies. We also handsearched selected journals, conference proceedings, and relevant guidelines. We updated this search in March 2018, but we have not yet incorporated these results.

SELECTION CRITERIA

We considered full-text diagnostic test accuracy studies of any individual index test, or a combination of tests, against a reference standard. Participants were adults without obvious airway abnormalities, who were having laryngoscopy performed with a standard laryngoscope and the trachea intubated with a standard tracheal tube. Index tests included the Mallampati test, modified Mallampati test, Wilson risk score, thyromental distance, sternomental distance, mouth opening test, upper lip bite test, or any combination of these. The target condition was difficult airway, with one of the following reference standards: difficult face mask ventilation, difficult laryngoscopy, difficult tracheal intubation, and failed intubation.

DATA COLLECTION AND ANALYSIS

We performed screening and selection of the studies, data extraction and assessment of methodological quality (using QUADAS-2) independently and in duplicate. We designed a Microsoft Access database for data collection and used Review Manager 5 and R for data analysis. For each index test and each reference standard, we assessed sensitivity and specificity. We produced forest plots and summary receiver operating characteristic (ROC) plots to summarize the data. Where possible, we performed meta-analyses to calculate pooled estimates and compare test accuracy indirectly using bivariate models. We investigated heterogeneity and performed sensitivity analyses.

MAIN RESULTS

We included 133 (127 cohort type and 6 case-control) studies involving 844,206 participants. We evaluated a total of seven different prespecified index tests in the 133 studies, as well as 69 non-prespecified, and 32 combinations. For the prespecified index tests, we found six studies for the Mallampati test, 105 for the modified Mallampati test, six for the Wilson risk score, 52 for thyromental distance, 18 for sternomental distance, 34 for the mouth opening test, and 30 for the upper lip bite test. Difficult face mask ventilation was the reference standard in seven studies, difficult laryngoscopy in 92 studies, difficult tracheal intubation in 50 studies, and failed intubation in two studies. Across all studies, we judged the risk of bias to be variable for the different domains; we mostly observed low risk of bias for patient selection, flow and timing, and unclear risk of bias for reference standard and index test. Applicability concerns were generally low for all domains. For difficult laryngoscopy, the summary sensitivity ranged from 0.22 (95% confidence interval (CI) 0.13 to 0.33; mouth opening test) to 0.67 (95% CI 0.45 to 0.83; upper lip bite test) and the summary specificity ranged from 0.80 (95% CI 0.74 to 0.85; modified Mallampati test) to 0.95 (95% CI 0.88 to 0.98; Wilson risk score). The upper lip bite test for diagnosing difficult laryngoscopy provided the highest sensitivity compared to the other tests (P < 0.001). For difficult tracheal intubation, summary sensitivity ranged from 0.24 (95% CI 0.12 to 0.43; thyromental distance) to 0.51 (95% CI 0.40 to 0.61; modified Mallampati test) and the summary specificity ranged from 0.87 (95% CI 0.82 to 0.91; modified Mallampati test) to 0.93 (0.87 to 0.96; mouth opening test). The modified Mallampati test had the highest sensitivity for diagnosing difficult tracheal intubation compared to the other tests (P < 0.001). For difficult face mask ventilation, we could only estimate summary sensitivity (0.17, 95% CI 0.06 to 0.39) and specificity (0.90, 95% CI 0.81 to 0.95) for the modified Mallampati test.

AUTHORS' CONCLUSIONS

Bedside airway examination tests, for assessing the physical status of the airway in adults with no apparent anatomical airway abnormalities, are designed as screening tests. Screening tests are expected to have high sensitivities. We found that all investigated index tests had relatively low sensitivities with high variability. In contrast, specificities were consistently and markedly higher than sensitivities across all tests. The standard bedside airway examination tests should be interpreted with caution, as they do not appear to be good screening tests. Among the tests we examined, the upper lip bite test showed the most favourable diagnostic test accuracy properties. Given the paucity of available data, future research is needed to develop tests with high sensitivities to make them useful, and to consider their use for screening difficult face mask ventilation and failed intubation. The 27 studies in 'Studies awaiting classification' may alter the conclusions of the review, once we have assessed them.

Randomized Comparison of Isoflurane versus Sevoflurane and Desflurane for Maintenance of Ambulatory Anesthesia

Background:

Ambulatory surgeries demand safe anesthesia with faster recovery which makes it expensive due to the cost of inhalational anesthetic agents such as sevoflurane and desflurane. Isoflurane is inexpensive agent but can cause delayed recovery. The aim of this study was to evaluate cost-benefit ratio of all three agent with respect to recovery and safety profile

Materials and Methods:

Patients posted for elective ambulatory surgeries were divided into three groups. Suitable size laryngeal mask airway was inserted following induction with propofol and vecuronium. Anesthesia was maintained on low-flow anesthesia with inhalational agent as isoflurane for Group I, sevoflurane for Group II and Group III received desflurane. Patients were monitored for recovery as per modified Aldrete score and as per postanesthesia discharge scoring system for discharge from hospital. Cost analysis was done by Dion's formula. Statistical analysis was done with analysis of variance for recovery profile, Chi-square test for safety profile and Kruskal Wallis test for cost comparison between groups.

Results:

Patient characteristics and duration of anesthesia were similar in all three groups. Time to eye-opening was significantly less with desflurane than sevoflurane and isoflurane (P = 0.001). Time to home readiness was similar in all three groups (P = 0.451). The incidence of airway irritation, pain, and nausea/vomiting was similar in all three groups. Cost of Group I was statistically lower than other two groups (P = 0.00).

Conclusion:

Home readiness and safety profile were comparable between agents; the cost involved was the least with isoflurane.

Comparison of the Disposable Streamlined Liner of the Pharynx Airway and the Disposable I-gel in Anaesthetized, Paralyzed Adults: A Randomized Prospective Study

Introduction. This study compared streamlined liner of the pharynx airway (SLIPA) and I-gel noninflatable, single-use, supraglottic airway device (SAD) performance in anesthetized, paralyzed adults. Methods. Eighty adults (ASA physical statuses I–III) who were undergoing elective procedures under general anesthesia with an SAD were enrolled in this prospective, randomized, single-blind study. Subjects were randomly and evenly assigned to the SLIPA or I-gel group for intraoperative airway management. Ease and number of insertions, insertion time, oropharyngeal sealing pressure, hemodynamic response, oxygen saturation (SpO₂), end-tidal CO₂ (EtCO₂), and peri- and postoperative complications were examined. Results. The SLIPA and I-gel devices were successfully inserted in 100% and 95% of subjects, respectively. In two I-gel subjects (5%), ventilation was not possible after two attempts, but a size 55 SLIPA was successfully inserted in both cases. Forty-two and 38 patients were ultimately included in the SLIPA and I-gel groups, respectively. Insertion time was significantly shorter with the SLIPA (11.19 ± 3.03 s) than with the I-gel (15.05 ± 6.37 s, P = 0.003). Oropharyngeal sealing pressure was significantly higher in SLIPA (28.76 ± 3.11 cmH₂O) than in I-gel (25.9 ± 3.65 cmH₂O) subjects (P = 0.001). Blood staining occurred more frequently in SLIPA (n = 8, 19.0%) than in I-gel (n = 5, 13.2%) patients (P < 0.01). Heart rate, mean arterial blood pressure, SpO₂, and EtCO₂ were not significantly different between groups. Conclusion. Although blood staining incidence was higher, SLIPA insertion was easier and faster than I-gel insertion. The SLIPA provided better airway sealing pressure. Both devices had similar mechanical ventilation and oxygenation characteristics and comparable hemodynamic stability. Both noninflatable SADs are useful, but SLIPA rapid insertion and good airway sealing make it an effective alternative to the I-gel.

Clinical evaluation of the Baska Mask laryngeal mask in adult patients in ambulatory surgery

OBJECTIVE

To evaluate the clinical performance of the Baska Mask, a new second-generation supraglottic airway device with a self-inflating cuff and two side suction channels for continuous aspiration.

MATERIAL AND METHODS

Eighty adult patients without difficult airways were prospectively included. Ease of insertion and number of attempts needed, quality of ventilation, airway seal pressure, fibreoptic view, ease of gastric access, and complications were assessed. Sizes 3, 4, 5 were analyzed and compared.

RESULTS

First attempt insertion success rate was 88% and the overall rate was 100%, although additional maneuvers were necessary in 44% of the cases. The ventilation was adequate in 96%, with 39% of them requiring adjusting maneuvers. Size 3 needed significantly less adjustments, and achieved a higher seal pressure than sizes 4 and 5 combined. The airway seal pressure was 33 ± 7 cm H2O. Complete or partial vocal cords were visible in 90% of the 66 cases assessed. Partial obstruction, caused by distortion of the cuff-free border, was seen in 5%, and no glottic structures were identified in 5%. Gastric access was easy in all cases. Complications were mild and transient.

CONCLUSIONS

The Baska Mask achieves a high seal pressure, effective ventilation, and a quick access to drain gastric contents. However, additional adjustment maneuvers are frequently required to insert the mask and to optimize ventilation.

Application of process improvement principles to increase the frequency of complete airway management documentation

BACKGROUND

Process improvement in healthcare delivery settings can be difficult, even when there is consensus among clinicians about a clinical practice or desired outcome. Airway management is a medical intervention fundamental to the delivery of anesthesia care. Like other medical interventions, a detailed description of the management methods should be documented. Despite this expectation, airway documentation is often insufficient. The authors hypothesized that formal adoption of process improvement methods could be used to increase the rate of "complete" airway management documentation.

METHODS

The authors defined a set of criteria as a local practice standard of "complete" airway management documentation. The authors then employed selected process improvement methodologies over 13 months in three iterative and escalating phases to increase the percentage of records with complete documentation. The criteria were applied retrospectively to determine the baseline frequency of complete records, and prospectively to measure the impact of process improvements efforts over the three phases of implementation.

RESULTS

Immediately before the initial intervention, a retrospective review of 23,011 general anesthesia cases over 6 months showed that 13.2% of patient records included complete documentation. At the conclusion of the 13-month improvement effort, documentation improved to a completion rate of 91.6% (P<0.0001). During the subsequent 21 months, the completion rate was sustained at an average of 90.7% (SD, 0.9%) across 82,571 general anesthetic records.

CONCLUSION

Systematic application of process improvement methodologies can improve airway documentation and may be similarly effective in improving other areas of anesthesia clinical practice.

Effects of fentanyl administration before induction of anesthesia and placement of the Laryngeal Mask Airway: a randomized, placebo-controlled trial

STUDY OBJECTIVE

To assess the effects of fentanyl administered before induction of anesthesia on movement and airway responses during desflurane anesthesia via the Laryngeal Mask Airway (LMA).

DESIGN

Randomized, double-blinded, controlled trial.

STUDY SETTING

Tertiary-care academic center.

PATIENTS

100 adult, ASA physical status 1, 2, and 3 patients undergoing ambulatory surgery.

INTERVENTIONS

Patients were administered fentanyl 1 μg/kg (n=51) or saline (n=49) 3 to 5 minutes before induction with propofol 2-2.5 mg/kg intravenously (IV), followed by LMA placement. Anesthesia was maintained with desflurane titrated to a bispectral index (BIS) of 50-60 and 50% nitrous oxide in oxygen, and fentanyl 25 μg boluses were titrated to respiratory rate.

MEASUREMENTS

Apnea occurrence and duration of manual ventilation, as well as frequency and severity of movement, coughing, breath holding, and laryngospasm were recorded.

MAIN RESULTS

Two patients in each group were excluded from analysis. The fentanyl pretreatment group had a higher frequency of apnea (94% vs 64%; P=0.0003) and longer duration of manual ventilation (3 [interquartile range (IQR), 1.5-5] min vs 1 [0-1.5] min; P<0.0001) at induction. In contrast, the fentanyl pretreatment group had a lower frequency of movements (16% vs 51%;P=0.0001). The rates of intraoperative breath holding (6.1% vs 8.5%) and laryngospasm (2% vs 4.3%) in the two groups were similar. All subjects experiencing laryngospasm were smokers. Adjusting for smoking status did not affect the differences noted in apnea, duration of manual ventilation, or movement between groups; however, coughing occurrence was statistically higher in the placebo group (P=0.043).

CONCLUSIONS

Preinduction fentanyl increased the frequency of apnea at induction and duration of manual ventilation, but reduced the frequency of movements. In addition, it reduced intraoperative coughing in smokers.

Regional anaesthesia with sedation protocol to safely debride sacral pressure ulcers

A treatment challenge for patients with sacral pressure ulcers is balancing the need for adequate surgical debridement with appropriate anaesthesia management. We are functioning under the hypothesis that regional anaesthesia has advantages over general anaesthesia. We describe our regional anaesthesia protocol for perioperative and postoperative management.