Teaching with a video system improves the training period but not subsequent success of tracheal intubation with the Bullard laryngoscope

BACKGROUND: The Bullard laryngoscope is useful for the management of a variety of airway management scenarios. Without the aid of a video system, teaching laryngoscopy skills occurs with indirect feedback to the instructor. The purpose of this study was to determine if use of a video system would speed the process of learning the Bullard laryngoscope or improve the performance (speed or success) of its use. METHODS: Thirty-six anesthesia providers with no previous Bullard laryngoscope experience were randomly divided into two groups: initial training (first 15 intubations) with looking directly through the eyepiece (n = 20), or with the display of the scope on a video monitor (n = 16). The subjects each then performed 15 Bullard intubations by looking directly through the eyepiece. RESULTS: There was not an overall significant difference in laryngoscopy or intubation times between the groups. When only the first 15 intubations were considered, the laryngoscopy time was shorter in the video group (26 +/- 24) than in the nonvideo group (32 +/- 34; P< 0.04). In the first 15 patients, there were fewer single attempts at intubation (67.9% vs 80.3%; P< 0.002) and more failed intubations (17.2% vs 6.0%; P< 0.0001) in the nonvideo group. CONCLUSIONS: In conclusion, the authors have shown that use of a video camera decreases time for laryngoscopic view and improves success rate when the Bullard laryngoscope is first being taught to experienced clinicians. However, these benefits are not evident as more experience with the Bullard laryngoscope is achieved, such that no difference in skill with the Bullard laryngoscope is discernible after 15 intubations whether a video system was used to teach this technique.     

Comparison of the Bullard and Macintosh Laryngoscopes for Endotracheal Intubation of Patients with a Potential Cervical Spine Injury

Background: In the emergency trauma situation, in-line stabilization (ILS) of the cervical spine is used to reduce head and neck extension during laryngoscopy. The Bullard laryngoscope may result in less cervical spine movement than the Macintosh laryngoscope. The aim of this study was to compare cervical spine extension (measured radiographically) and time to intubation with the Bullard and Macintosh laryngoscopes during a simulated emergency with cervical spine precautions taken.

Methods: Twenty-nine patients requiring general anesthesia and endotracheal intubation were studied. Patients were placed on a rigid board and anesthesia was induced. Laryngoscopy was performed on four occasions: with the Bullard and Macintosh laryngoscope both with and without manual ILS. Cricoid pressure was applied with ILS. To determine cervical spine extension, radiographs were exposed before and during laryngoscopy. Times to intubation and grade view of the larynx were also compared.

Results: Cervical spine extension (occiput-C5) was greatest with the Macintosh laryngoscope (25.9 [degree sign] +/- 2.8 [degree sign]). Extension was reduced when using the Macintosh laryngoscope with ILS (12.9 +/- 2.1 [degree sign]) and the Bullard laryngoscope without stabilization (12.6 +/- 1.8 [degree sign]; P < 0.05). Times to intubation were similar for the Macintosh laryngoscope with ILS (20.3 +/- 12.8 s) and for the Bullard without ILS (25.6 +/- 10.4 s). Manual ILS with the Bullard laryngoscope results in further reduction in cervical spine extension (5.6 +/- 1.5 [degree sign]) but prolongs time to intubation (40.3 +/- 19.5 s; P < 0.05).     

Effect of Cricoid Pressure on the Success of Endotracheal Intubation with a Lightwand

Background: The lightwand may be useful as an alternative for tracheal intubation during a rapid-sequence induction of anesthesia in the presence of a full stomach. This study was undertaken to assess the effect of application of cricoid pressure on the success of lightwand intubation.

Methods: Sixty adult female patients presenting for abdominal hysterectomy were randomly allocated to lightwand intubation with and without cricoid pressure. The time to successful intubation and number of attempts were recorded.

Results: All 30 patients allocated to intubation without cricoid pressure were intubated successfully at the first attempt within a median time of 28 s (95% confidence interval, 18-77 s). Lightwand intubation with cricoid pressure was successful in 26 of 30 patients at the first attempt, but the median time to successful intubation was significantly longer at 48.5 s (95% confidence interval, 36-78 s;P = 0.001). Three patients required two attempts for successful intubation, and one could not be intubated with the lightwand while cricoid pressure was being applied.     

Successful airway management of a patient with a known difficult airway with the Direct Coupler Interface Video Laryngoscope

We present the case of a patient who first presented with unexpected difficult laryngoscopy and intubation after induction of general anesthesia. After multiple failed attempts using direct laryngoscopy, tracheal intubation was successfully performed with the Intubating Laryngeal Mask Airway. He returned to the operating room 5 days later for another surgical procedure, and intubation was performed with the Direct Coupler Interface Video Laryngoscope on the first attempt by the same anesthesiologist.     

Success of Tracheal Intubation with Intubating Laryngeal Mask Airways: A Randomized Trial of the LMA Fastrach(TM) and LMA CTrach(TM)

Background: The LMA CTrach(TM) system (The Laryngeal Mask Company, Singapore) is a development of the LMA Fastrach(TM) system (The Laryngeal Mask Company, Singapore), with integrated fiberoptic bundles and a detachable liquid crystal display viewer. This randomized study of 271 patients compared tracheal intubation with these two systems.

Methods: In both groups, ventilation was optimized after insertion of the laryngeal mask conduit before proceeding further: intubation with the LMA Fastrach(TM), and optimizing the conduit placement and view and then intubation with the LMA CTrach(TM). The first-attempt and overall success rates of tracheal intubation, and the times required, were recorded.

Results: Tracheal intubation was successful on the first attempt in 93.3% of patients with the LMA CTrach(TM) and 67.9% of patients with the LMA Fastrach(TM) (P < 0.001). The success rates within three attempts were 100% with the LMA CTrach(TM) and 96.4% with the LMA Fastrach(TM) (P = 0.06). The median (interquartile range) time for the complete tracheal intubation process was 116 (82-156) s with the LMA CTrach(TM) and 100 (74-121) s with the LMA Fastrach(TM) (P = 0.002). There was no correlation between the grade of conventional laryngoscopy and success of intubation with either system.     

Failed Debridement and Implant Retention Does Not Compromise the Success of Subsequent Staged Revision in Infected Total Knee Arthroplasty

BackgroundPeriprosthetic joint infection (PJI) is the leading cause of early revisions after total knee arthroplasty. Debridement, antibiotics, and implant retention (DAIR) procedures are often the initial treatment for PJI. However, there is concern that failed DAIR undermines the future success of revision procedures. This study aims to investigate the impact of DAIR on the success of subsequent staged revisions for PJI.MethodsA multicenter retrospective review was performed over a 15-year period. Treatment success was defined as implant retention without the use of long-term suppressive antibiotics. This was compared between patients who underwent a staged revision as the first procedure for PJI (staged-only) and patients who failed DAIR before staged revision (F-DAIR). Competing risk survival analysis was performed to compare the 2 groups and considered for patient demographics, American Society of Anesthesiologists score, organism type, body mass index, age of prosthesis, and duration of symptoms.ResultsOf 291 eligible patients, 63 underwent staged revision and 228 underwent DAIR as the first procedure for PJI. Of the 228 DAIR patients, 75 failed DAIR and underwent subsequent staged revision (F-DAIR). At mean follow-up of 6.2 years, the success rate was 72% in the F-DAIR group and 81% in the staged-only group. On survival analysis, there was no significant difference in subdistribution hazard ratio comparing the probability of failure (implant retention) in the 2 treatments groups (subdistribution hazard ratio = 0.72; 95% confidence interval 0.32-1.61; P = .42).ConclusionThis study suggested that a previously failed DAIR does not compromise the success rate of a subsequent staged revision.     

Isoflurane, but Not Halothane, Improves Indices of Diastolic Performance in Dogs with Rapid Ventricular, Pacing-induced Cardiomyopathy

Background: The left ventricular (LV) mechanical effects of isoflurane and halothane were examined in dogs with rapid LV pacing-induced cardiomyopathy. These experiments tested the hypothesis that isoflurane and halothane differentially enhance indices of diastolic performance in dogs with moderate LV dysfunction.

Methods: Eight dogs were chronically instrumented for measurement of LV and aortic pressures, subendocardial segment length, and cardiac output. Contractility was quantified by preload recruitable stroke work (Mw). Diastolic function was evaluated with a time constant of isovolumic relaxation (tau), segment lengthening velocities and time-velocity integrals during early filling (dL/dtE and TVI-E) and atrial systole (dL/dtA and TVI-A), and a regional chamber stiffness constant (Kp). Hemodynamics and LV function were recorded in the conscious state before pacing. The left ventricles of the dogs were then continuously paced at ventricular rates between 220 and 240 beats *symbol* min sup -1 for 10 plus/minus 1 days and monitored on a daily basis. After the development of moderate LV dysfunction, pacing was temporarily discontinued, and dogs were studied in sinus rhythm in the conscious state and after 20 min equilibration at 1.1, 1.4, and 1.7 minimum alveolar concentration isoflurane and halothane on separate days.

Results: Chronic rapid pacing increased baseline (sinus rhythm) heart rate, LV end-diastolic pressure, and end-diastolic segment length and decreased mean arterial pressure, LV systolic pressure, and cardiac output. Mw decreased and tau and Kp increased, consistent with LV systolic and diastolic dysfunction. Reductions in dL/dtE /dL/dt sub A and TVI-E/A occurred, which indicated that LV filling was more dependent on atrial systole. In dogs with cardiomyopathy, isoflurane and halothane increased heart rate and decreased mean arterial pressure, LV systolic pressure, LV end-diastolic pressure, cardiac output, Mw, and Kp. Decreases in LV end-diastolic pressure were more pronounced in dogs anesthetized with 1.1 minimum alveolar concentration isoflurane compared with halothane. Halothane-induced decreases Mw were greater than those observed with equi-minimum alveolar concentration isoflurane. A reduction in tau and increases in TVI-E/TVI-A and the ratio of early to total LV filling were observed with isoflurane. In contrast, halothane caused dose-related reductions in dL/dtE, dL/dt sub A, TVI-E, and TVI-A, and did not improve the ratios of these variables.     

环甲膜穿刺在急诊饱胃清醒气管插管中的应用

目的探讨环甲膜穿刺在急诊饱胃病人清醒气管插管中应用的可行性及安全性。方法急诊饱胃病人37例,气管插管采用慢诱导,静注氟芬合剂,丁卡因喷喉,环甲膜穿刺注入利多卡因,后行气管插管。结果在整个插管过程中,3例病人不适反应稍大,其余均能很好地耐受气管插管,无气道痉挛和呛咳等动作。37例病人整个插管监护过程中,心电图及血压变化在预料范围内,SpO2无下降,无一例出现反流及误吸。结论环甲膜穿刺后行气道表面麻醉应用于清醒气管插管具有较高的安全性和可行性。     

Involuntary Wheel Running Improves but Does Not Fully Reverse the Deterioration of Bone Structure of Obese Rats Despite Decreasing Adiposity

This study investigated whether exercise or antioxidant supplementation with vitamin C and E during exercise affects bone structure and markers of bone metabolism in obese rat. Sprague–Dawley rats, 6-week old, were fed a normal-fat diet (NF, 10 % kcal as fat) and a high-fat diet (HF, 45 % with extra fat from lard) ad libitum for 14 weeks. Then, rats on the high-fat diet were assigned randomly to three treatment groups for additional 12 weeks with forced exercise: HF; HF + exercise (HF + Ex); and HF with vitamin C (0.5 g ascorbate/kg diet) and vitamin E (0.4 g α-tocopherol acetate/kg diet) supplementation + exercise (HF + Ex + VCE). At the end of the study, body weight and fat (%) were similar among NF, HF + Ex, and HF + Ex + VCE, whereas HF had greater body weight and fat (%) than other groups. Compared to NF, HF had elevated serum leptin, tartrate-resistant acid phosphatase (TRAP), and IGF-1; increased trabecular separation and structural model index; and lowered bone mineral density, trabecular connectivity density, and trabecular number in distal femur, while HF + Ex and HF + Ex + VCE had elevated serum TRAP and decreased bone volume/total volume and trabecular number of distal femurs. Compared to HF, HF + Ex and HF + Ex + VCE had decreased serum TRAP and osteocalcin and improved bone structural properties of the distal femur. These findings suggest that exercise, while decreasing body fat, does not fully protect against the negative skeletal effects of existing obesity induced by a high-fat diet. Furthermore, vitamin C and E supplementation has no additional benefits on bone structural properties during exercise.     

Corticosteroids and Inhaled Salbutamol in Patients with Reversible Airway Obstruction Markedly Decrease the Incidence of Bronchospasm after Tracheal Intubation

Background: In patients with bronchial hyperreactivity, airway instrumentation can evoke life-threatening bronchospasm. However, the best strategy for the prevention of bronchospasm has not been defined. Therefore, in a randomized, prospective, placebo-controlled study, the authors tested whether prophylaxis with either combined salbutamol-methylprednisolone or salbutamol alone (1) improves lung function and (2) prevents wheezing after intubation.

Methods: Thirty-one patients with partially reversible airway obstruction (airway resistance > 180%, forced expiratory volume in 1 s [FEV1] < 70% of predicted value, and FEV1 increase > 10% after two puffs of salbutamol), who were naive to anti-obstructive treatment, were randomized to receive daily for 5 days either 3 x 2 puffs (0.2 mg) of salbutamol alone (n = 16) or salbutamol combined with methylprednisolone (40 mg/day orally) (n = 15). Lung function was evaluated daily. Another 10 patients received two puffs of salbutamol 10 min before anesthesia. In all patients, wheezing was assessed before and 5 min after tracheal intubation.

Results: Within 1 day, both salbutamol and salbutamol-methylprednisolone treatment significantly improved airway resistance (salbutamol, 4.3 +/- 2.0 [SD] to 2.9 +/- 1.3 mmHg [middle dot] s [middle dot] l-1; salbutamol-methylprednisolone, 5.5 +/- 2.9 to 3.4 +/- 1.7 mmHg [middle dot] s [middle dot] l-1) and FEV1 (salbutamol, 1.79 +/- 0.49 to 2.12 +/- 0.61 l; salbutamol-methylprednisolone, 1.58 +/- 0.66 to 2.04 +/- 1.05 l) to a steady state, with no difference between groups. However, regardless of whether single-dose salbutamol preinduction or prolonged salbutamol treatment was used, most patients (8 of 10 and 7 of 9) experienced wheezing after intubation. In contrast, only one patient receiving additional methylprednisolone experienced wheezing (P = 0.0058).     

Effect of Prophylactic Bronchodilator Treatment with Intravenous Colforsin Daropate, a Water-soluble Forskolin Derivative, on Airway Resistance after Tracheal Intubation

Background: After induction of anesthesia, lung resistance increases. The authors hypothesized that prophylactic bronchodilator treatment with intravenous colforsin daropate, a water-soluble forskolin derivative, before tracheal intubation would result in decreased lung resistance and increased lung compliance after tracheal intubation when compared with placebo medication.

Methods: Forty-six adult patients were randomized to placebo or colforsin daropate treatment. Patients in the control group received normal saline; patients in the colforsin group received 0.75 [mu]g [middle dot] kg-1 [middle dot] min-1 colforsin daropate intravenously until the study ended. Thirty minutes after the study began, the authors administered 5 mg/kg thiamylal and 5 [mu]g/kg fentanyl for induction of general anesthesia and 0.3 mg/kg vecuronium for muscle relaxation. A 15-mg [middle dot] kg-1 [middle dot] h-1 continuous infusion of thiamylal followed anesthetic induction. Four, 8, 12, and 16 min after tracheal intubation, mean airway resistance (Rawm), expiratory airway resistance (Rawe), and dynamic lung compliance (Cdyn) were measured.

Results: Patients in the colforsin group had significantly lower Rawm and Rawe and higher Cdyn after intubation than those in the control group. Differences in Rawm, Rawe, and Cdyn between the two groups persisted through the final measurement at 16 min. At 4 min after intubation, smokers had a higher Rawm and a lower Cdyn than nonsmokers in the control group. After treatment by intravenous colforsin daropate, Rawm, Rawe, and Cdyn values were similar for smokers and nonsmokers after tracheal intubation.