Video-Assisted Versus Conventional Tracheal Intubation in Morbidly Obese Patients

Background  We compared tracheal intubation characteristics and arterial oxygenation quality during airway management of morbidly obese patients whose trachea was intubated under video assistance with the LMA CTrach™ (SEBAC, Pantin, France) or the Airtraq™ laryngoscope (VYGON, écouen, France) with that of the conventional Macintosh laryngoscope. Methods  After standardized induction of anesthesia, 318 morbidly obese patients scheduled for elective morbid obesity surgery received tracheal intubation with the LMA CTrach™, the Airtraq™ laryngoscope, or the conventional Macintosh laryngoscope. Duration of apnea, time to tracheal intubation, and oxygenation quality during airway management were compared between the LMA CTrach™ and the laryngoscope groups. Results  Patients’ characteristics were similar in the three groups. The success rate for tracheal intubation was 100% with the LMA CTrach™ and the Airtraq™ laryngoscope. One patient of the Macintosh laryngoscope group received LMA CTrach™ intubation because of early arterial oxygen desaturation associated with unstable facemask ventilation. The duration of apnea was shorter with the LMA CTrach™ than that of the Airtraq™ laryngoscope and the Macintosh laryngoscope. The duration tracheal intubation was shorter with the Airtraq™ laryngoscope than with the Macintosh laryngoscopes and the LMA CTrach™. During airway management, arterial oxygenation was of better quality with the LMA CTrach™ and the Airtraq™ laryngoscope than that of the Macintosh laryngoscope. Conclusion  Because LMA CTrach™ promoted short apnea time and the Airtraq™ laryngoscope allowed early definitive airway, both video-assisted tracheal intubation devices prevented most serious arterial oxygenation desaturation evidenced during tracheal intubation of morbidly obese patients with the conventional Macintosh laryngoscope. Support was provided solely from department sources. LMA and PRODOL Companies promoted material support for the airways.     

气管插管病人胃管置入方法研究

目的 探讨气管插管病人胃管置入方法。方法 将264例气管插管病人随机分为卡弗放气组(A组)、卡费不放气组(B组)、头部前倾组(C组)和镇静状态下牵拉气管组(D组)各66例；观察并比较一次置管成功率，置管前后HR、SpO2及置管过程中呛咳发生率。结果①一次置管成功率比较，A组与B组差异无显著性意义(P＞0．05)，C组显著低于A、B组(均P＜0．05)，D组显著高于其它各组(均P＜0．01)。②置管后HR、SpO2与各自置管前相比，B、D组无显著性意义(均P＞0．05)，A、C组HR明显加快、SpO2明显降低(P＜0．05，P＜0．01）；C组置管过程中呛咳发生率显著高于其他各组(均P＜0．01)。结论 对气管插管病人在镇静状态下牵拉气管的同时置入胃管准确性高、不良反应少。     

Difficult Tracheal Intubation in Obese Gastric Bypass patients

Background

Endotracheal intubation is commonly perceived to be more difficult in obese patients than in lean patients. Primarily, we investigated the association between difficult tracheal intubation (DTI) and obesity, and secondarily, the association between DTI and validated scoring systems used to assess the airways, the association between DTI and quantities of anesthetics used to induce general anesthesia, and the association between DTI and difficulties with venous and arterial cannulation.

Methods

This is a monocentric prospective observational clinical study of a consecutive series of 539 obese patients undergoing gastric bypass. Tracheal intubation was done preoperatively together with scoring of Intubation Score (IS), Mallampati (MLP), and Cormack-Lehane classification (CLC) and registration of the quantities of anesthetics and total attempts on cannulation.

Results

The overall proportion of patients with DTI was 3.5 % and the patients with DTI were more frequently males, had higher CLC, higher American Society of Anesthesiologists physical status classification (ASA), and noticeably, a lower BMI compared to the patients with easy tracheal intubation. After adjustment with multivariable analyses body mass index (BMI) <40, CLC >2, ASA scores >2, and male gender were risk factors of DTI. Males generally had higher CLC, MLP, and ASA scores compared to females, but no difference in BMI. There was no difference in quantities of anesthetics used between the two groups with or without DTI. Intra-venous and intra-arterial cannulation was succeeded in first attempt in 85 and 86 % of the patients, respectively, and there were no association between BMI and difficult vascular access.

Conclusions

We found no association between increasing BMI and DTI.

     

Efficacy of the Self-inflating Bulb in Confirming Tracheal Intubation in the Morbidly Obese

Background: This study was designed to determine the incidence of false-negative and false-positive results when the self-inflating bulb (SIB) is used to differentiate tracheal from esophageal intubation in morbidly obese patients using two techniques. In technique 1, the SIB is compressed before it is connected to the tube; in technique 2, the SIB is compressed after connection to the tube.

Methods: With institutional review board approval, 54 consenting adult morbidly obese patients (body mass index > 35) undergoing elective surgical procedures were included in the study. After anesthetic induction and muscle relaxation, both the trachea and esophagus were intubated under direct vision with identical cuffed tubes. The efficacy of the SIB in verifying the position of both tubes was tested by a second anesthesiologist. The speed of reinflation was graded as rapid (< 4 s) or none (> 4 s), using both techniques. In the case of tracheal intubation, the absence of reinflation was recorded as a false-negative, whereas in cases of esophageal intubation, rapid reinflation was recorded as a false-positive. Identification of tube location by the second anesthesiologist was based on SIB reinflation results from techniques 1 and 2, as well as the presence of a flatuslike sound elicited by technique 2 in esophageally placed tubes. All patients were retested by the SIB after receiving three breaths of 400-500 ml each. In all patients exhibiting false-negative results, six obese patients exhibiting true-positive results, and four nonobese patients exhibiting true-positive results, tracheal responses to the SIB maneuvers were observed directly by a flexible fiberoptic bronchoscope incorporating an airtight system, 15-20 min after mechanical ventilation was instituted.

Results: The incidence of false-negative results was initially 30% with technique 1 and 11% with technique 2, but decreased to 4% when technique 2 was used after the delivery of three breaths. The second anesthesiologist initially identified tube location in 92.5% of patients correctly. After the delivery of three breaths, tube location was correctly identified in 96.3% of patients. Fiberoptic bronchoscopic examination of the patients exhibiting false-negative results revealed exaggerated inward bulging of the posterior tracheal membrane during reinflation of the SIB when technique 1 was used.     

Submandible Angle in Nonobese Patients with Difficult Tracheal Intubation

Background: Although functional immobility of craniofacial structures during direct laryngoscopy may cause difficult tracheal intubation (DTI), there may be an unfavorable specific craniofacial feature for successful tracheal intubation. The aim of this study was to identify the specific craniofacial features associated with DTI.

Methods: Digital photographs of nonobese patients with DTI (23 males and 18 females) and age- and body mass index-matched patients with easy tracheal intubation (ETI) (16 males and 16 females) were taken and used for measurements of various craniofacial dimensions. Composite facial pictures of each patient group were constructed for visualization of differences of the craniofacial features.

Results: Mandible position angle was significantly smaller in DTI males than in male patients with ETI. Submandible angle was significantly larger in both male and female DTI patients than in patients with ETI. Logistic regression analysis revealed that the submandible angle was a significant and independent variable associated with DTI among the craniofacial dimensions for both sexes. The specific craniofacial features were visually more evident in the profile in than frontal composites.     

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。     

A Multicenter Clinical Study of the Safety and Activity of Maleimide-Polyethylene Glycol-modified Hemoglobin (Hemospan®) in Patients Undergoing Major Orthopedic Surgery

Background: Hemospan(R) (Sangart Inc., San Diego, CA), a polyethylene glycol-modified hemoglobin with unique oxygen transport properties, has successfully completed a phase I trial in healthy volunteers. Because adverse events are expected to increase with age, the authors conducted a phase II safety study of Hemospan in elderly patients undergoing elective hip arthroplasty during spinal anesthesia.

Methods: Ninety male and female patients, American Society of Anesthesiologists physical status I-III, aged 50-89 yr, in six Swedish academic hospitals were randomly assigned to receive either 250 or 500 ml Hemospan or Ringer's acetate (30 patients/group) before induction of spinal anesthesia. Safety assessment included vital signs and Holter monitoring from infusion to 24 h, evaluation of laboratory values, and fluid balance. The hypothesis to be tested was that the incidence of adverse events would be no more frequent in patients who received Hemospan compared with standard of care (Ringer's acetate).

Results: Three serious adverse events were noted, none of which was deemed related to study treatment. Liver enzymes, amylase, and lipase increased transiently in patients in all three groups. There were no significant differences in electrocardiogram or Holter parameters, but there was a suggestion of more bradycardic events in the treated groups. Hypotension was less frequent in the treated patients compared with controls.     

Intrapatient Reproducibility of the BISxp® Monitor

Background: The Bispectral Index (BIS) reportedly reflects anesthetic depth. It is recommended that anesthetic agents should be titrated to maintain the BIS between 40 and 60 arbitrary BIS units during anesthesia. For anesthesia providers to follow this recommendation, the monitor should be predictably affected by different anesthetic agents and have good interpatient and intrapatient reproducibility. The authors hypothesized that when two BISxp(R) devices (Aspect Medical Systems, Newton, MA) are placed concurrently on the same patient, their readings are concordant throughout the anesthetic period.

Methods: Simultaneous BIS recordings from two BISxp(R) monitors were obtained during anesthesia at 5-s intervals from 12 participants.

Results: In total 22,860 concurrent paired BIS readings were obtained. For 10.7% of the time, there were sustained periods of 30 s or greater where the readings suggested a different depth of anesthesia. For 6% of the time, there were sustained periods of 30 s or greater where the readings differed by 10 or more arbitrary BIS units. The regression coefficient (R2) for the two devices was 0.65 (range, 0.35-0.92). There was zero bias between the devices, and the 95% limits of agreement ranged between -18 and +17.     

Psychological Profile and Outcome in Patients Undergoing Gastroplasty for Morbid Obesity

Eighteen out of 22 consecutive patients undergoing vertical banded gastroplasty were reviewed with regard to preoperative psychological assessment and postoperative outcome. Each patient was initially evaluated by a consultant liaison psychiatrist with regard to previous or ongoing psychological disturbance, and suitability for bariatric surgery. Patients could be grouped into three broad categories: Group A (seven patients) those with no psychiatric abnormality; Group B (six patients) those with minor psychiatric disorders such as sociopathic teenage behaviour, outpatient treatment for depression; and Group C (five patients) those with a history of major psychiatric disturbance such as depressive psychosis and drug dependency. Psychiatric morbidity had no adverse effect in terms of postoperative outcome or weight loss. Mean weight loss of 26%, 30% and 33% was recorded in groups A, B and C respectively after a mean follow-up period of 33 months following gastroplasty. The occurrence of postoperative psychiatric problems correlated closely with preoperative psychological assessment, with none of seven patients in group A but four of the five patients in group C requiring psychiatric management. Our findings indicate that psychiatric illness is not associated with poor outcome following surgery for morbid obesity and such patients should not be excluded if psychiatric support is available before and after surgery.