Increased Rate of Poor Laryngoscopic Views in Patients Scheduled for Cardiac Surgery Versus Patients Scheduled for General Surgery: A Propensity Score-Based Analysis of 21,561 Cases

Impact of Universal Use of the McGrath Videolaryngoscope as a Device for All Intubations in the Cardiac Operating Room. A Prospective Before-After VIDEOLAR-CAR Study

OBJECTIVE

Tracheal intubation in cardiac surgery patients has a higher incidence of difficult laryngoscopic views compared with patients undergoing other types of surgery. The authors hypothesized that using the McGrath Mac videolaryngoscope as the first intubation option for cardiac surgery patients improves the percentage of patients with "easy intubation" compared with using a direct Macintosh laryngoscope.

DESIGN

A prospective, observational, before-after study.

SETTING

At a tertiary-care hospital.

PARTICIPANTS

One thousand one hundred nine patients undergoing cardiac surgery.

INTERVENTION

Consecutive patients undergoing cardiac surgery were intubated using, as the first option, a Macintosh laryngoscope (preinterventional phase) or a McGrath Mac videolaryngoscope (interventional phase).

MEASUREMENTS AND MAIN RESULTS

The main objective was to assess whether the use of the McGrath videolaryngoscope, as the first intubation option, improves the percentage of patients with "easy intubation," defined as successful intubation on the first attempt, modified Cormack-Lehane grades of I or IIa, and the absence of the need for adjuvant airway devices. A total of 1,109 patients were included, 801 in the noninterventional phase and 308 in the interventional phase. The incidence of "easy intubation" was 93% in the interventional phase versus 78% in the noninterventional phase (p < 0.001). First-success-rate intubation was higher in the interventional phase (304/308; 98.7%) compared with the noninterventional phase (754/801, 94.1%; p = 0.005). Intubation in the interventional phase showed decreases in the incidence of difficult laryngoscopy (12/308 [3.9%] v 157/801 [19.6%]; p < 0.001), as well as moderate or difficult intubation (5/308 [1.6%] v 57/801 [7.1%]; p < 0.001).

CONCLUSIONS

The use of the McGrath videolaryngoscope as the first intubation option for tracheal intubation in cardiac surgery improves the percentage of patients with "easy" intubation," increasing glottic view and first-success-rate intubation and decreasing the incidence of moderate or difficult intubation.

Incidence of Difficult Laryngoscopy in Adult Congenital Heart Disease Patients: A Retrospective Cohort Study

OBJECTIVE

To identify the incidence of difficult intubation in patients with adult congenital heart disease (ACHD) undergoing cardiac surgery or catheterization.

DESIGN

A retrospective cohort study.

SETTING

A single-center academic quaternary pediatric hospital.

PARTICIPANTS

All patients were >18 years of age with ACHD undergoing endotracheal intubation within the Heart Center at Texas Children's Hospital between January 2012 and December 2019.

INTERVENTIONS

None.

MEASUREMENT AND MAIN RESULTS

A retrospective chart review was performed, including patient demographics, preoperative airway assessment and intraoperative airway management characteristics. Airways were categorized as difficult using the Pediatric Difficult Intubation registry operational definitions. For patients classified as having a difficult airway, the preoperative airway examination findings were recorded in addition to factors associated with difficult airway in the adult. The study authors identified 1,029 patients with ACHD who underwent procedures with anesthesia at their institution and were analyzed for the presence of difficult airway. In total, 878 patients were intubated, with 4.3% (n = 38) identified to have difficult airway. The presence of concomitant syndromes was greater in patients with difficult intubations and those who were not intubated compared with those who were not difficult intubations (23.7% and 17.2 v 7.5; p < 0.001), respectively. Most patients did not have typical signs associated with difficult intubation.

CONCLUSIONS

The study authors identified an incidence of difficult laryngoscopy in their cohort of ACHD patients to be 4.3%. Their incidences of difficult laryngoscopy were fewer than that reported in adult patients with noncongenital heart disease. Most importantly, the risk factors associated with difficult laryngoscopy in the normal adult may be different from those presenting with ACHD, necessitating further investigation.

Preoperative predictors of poor laryngoscope views in pediatric population undergoing cardiac catheterization

Background

The primary objective of this study was to identify pre-anesthetic airway assessment parameters that would predict Cormack and Lehane grade III and IV laryngoscopy views in pediatric patients undergoing cardiac catheterization procedures. The secondary end points were to identify factors that would contribute to difficult laryngoscope views in this subset of patients.

Settings and Design

Prospective observational study performed at a single tertiary cardiac care center.

Materials and Methods

199 children below 5 years of age undergoing elective cardiac catheterization were included. Pre-anesthetic airway assessment was done by modified Mallampati grading, lower lip to chin distance [LCD], tragus to mouth angle [TMA], thyromental distance [TMD], neck circumference [NC], and the ratio of height to thyromental distance [RHTMD]. Demographic data including American Society of Anesthesiologists physical status [ASA PS] were recorded for each child. Receiver Operating Characteristic curves were plotted and Areas Under the Curve were measured to identify the best cut off values for each of the airway evaluation method that would predict poor laryngoscopy views as well as assess their accuracy in doing so.

Results

LCD, TMD and low body mass index were found to have good sensitivity, specificity and accuracy in predicting Grade III and IV laryngoscope views. ASA PS grade III and above patients had a significantly higher incidence of poor laryngoscope visualization.

Conclusions

LCD, TMA, TMD, NC, RHTMD and BMI could all be used combinedly as screening tools during pre-anesthetic airway evaluation for predicting difficult laryngoscope views in children. Among these, LCD, TMD along with low body mass index might have better accuracy.

Management of the Difficult Airway in the Pediatric Patient

Loss of airway control in children, if not resolved quickly, will lead to devastating consequences. Successful management of the pediatric difficult airway, both anticipated and unanticipated, is facilitated by preprocedure assessment and preparation. Accessibility of and continued hands-on training with modern airway instruments, familiarization with difficult airway guidelines, and collaboration with multidisciplinary airway teams can aid in the management of the difficult pediatric airway. This review outlines the importance of airway assessment and advanced airway equipment for children. It also discusses difficult airway management techniques and algorithms for the management and rescue of the pediatric difficult airway.

Perioperative Care of the Obese Cardiac Surgical Patient

Morbid obesity is associated with impairment of cardiovascular, pulmonary, gastrointestinal, and renal physiology with significant perioperative consequences and has been linked with higher morbidity and mortality after cardiac surgery. Cardiac surgery patients have a higher incidence of difficult airway and difficult laryngoscopy than general surgery patients do, and obesity is associated with difficult mask ventilation and direct laryngoscopy. Positioning injuries occur more frequently because obese patients are at greater risk of pressure injury, such as rhabdomyolysis and compartment syndrome. Despite the association between obesity and several chronic disease states, the effects of obesity on perioperative outcomes are conflicting. Studies examining outcomes of overweight and obese patients in cardiac surgery have reported varying results. An "obesity paradox" has been described, in which the mortality for overweight and obese patients is lower compared with patients of normal weight. This review describes the physiologic abnormalities and clinical implications of obesity in cardiac surgery and summarizes recommendations for anesthesiologists to optimize perioperative care of the obese cardiac surgical patient.

Are cardiac surgical patients at increased risk of difficult intubation?

Background and Aims:

Safe airway management is the cornerstone of contemporary anaesthesia practice, and difficult intubation (DI) remains a major cause of anaesthetic morbidity and mortality. The surgical category, particularly cardiac surgery as a risk factor for DI has not been studied extensively. The aim of this study was to test the hypothesis whether cardiac surgical patients are at increased risk of DI.

Methods:

During the study, 627 patients (329 cardiac and 298 non-cardiac surgical) were enrolled. Pre-operative demographic and other variables associated with DI were assessed. Patients with Cormack Lehane grade III and IV or use of bougie in Cormack grade II were defined as DI. The incidence of anticipated and unanticipated DI was assessed. Factors associated with DI were described using univariate and multivariate logistic regression models.

Results:

The overall incidence of DI was 122/627 (19.46%). The incidence of DI was higher in cardiac surgery patients (24%) as compared to non-cardiac surgery patients (14.4% P = 0.002). On multivariate analysis, factors independently associated with DI were greater age, male sex, higher Mallampati grade, and anticipated DI, but not cardiac surgery. The incidence of unanticipated DI was 48.1% and 53.4% in cardiac and non-cardiac surgery patients, respectively.

Conclusion:

Although there was a higher incidence of DI in cardiac surgical patients, cardiac surgery is not an independent risk factor for DI. Rather, other factors play more important role. About half of the DI both in cardiac and non-cardiac surgeries were unanticipated.

Airway management of the cardiac surgical patients: Current perspective

The difficult airway (DA) is a common problem encountered in patients undergoing cardiac surgery. However, the challenge is not only just establishment of airway but also maintaining a definitive airway for the safe conduct of cardiopulmonary bypass from initiation to weaning after surgical correction or palliation, de-airing of cardiac chambers. This review describes the management of the DA in a cardiac theater environment. The primary aims are recognition of DA both anatomical and physiological, necessary preparations for (and management of) difficult intubation and extubation. All patients undergoing cardiac surgery should initially be considered as having potentially DA as many of them have poor physiologic reserve. Making the cardiac surgical theater environment conducive to DA management is as essential as it is to deal with low cardiac output syndrome or acute heart failure. Tube obstruction and/or displacement should be suspected in case of a new onset ventilation problem, especially in the recovery unit. Cardiac anesthesiologists are often challenged with DA while inducing general endotracheal anesthesia. They ought to be familiar with the DA algorithms and possess skill for using the latest airway adjuncts.