Cardiovascular changes following insertion of oropharyngeal and nasopharyngeal airways

McGrath Video Laryngoscopy Facilitates Routine Nasotracheal Intubation in Patients Undergoing Oral and Maxillofacial Surgery: A Comparison With Macintosh Laryngoscopy

PURPOSE

The McGrath video laryngoscope (VL) offers excellent laryngoscopic views and increases the success rate of orotracheal intubation in patients with normal and difficult airways. The purpose of this randomized controlled trial was to compare the McGrath VL with the Macintosh laryngoscope to investigate the efficacy of the McGrath VL for routine nasotracheal intubation in patients with an expected normal airway.

MATERIALS AND METHODS

To address the research purpose, the efficacy of the McGrath VL for routine nasotracheal intubation was compared with that of the Macintosh laryngoscope. The predictor variable was the laryngoscopic technique (McGrath VL vs Macintosh laryngoscope). The outcome variables were the time to successful intubation, laryngoscopic views before and after optimal external laryngeal manipulation (OELM), use of Magill forceps, ease of intubation, and severity of oropharyngeal bleeding.

RESULTS

Data from 35 patients undergoing oral and maxillofacial surgery were assessed. The time to intubation was 10.5 seconds shorter in the McGrath group than in the Macintosh group (34.4 ± 13.7 vs 44.9 ± 15.6 seconds; P = .004). The incidence of grade 1 glottic view before OELM was higher in the McGrath group than in the Macintosh group (83 vs 57%; P = .019). The frequency of Magill forceps use was lower in the McGrath group than in the Macintosh group (6 vs 34%; P = .003).

CONCLUSION

McGrath VL facilitates routine nasotracheal intubation in expected normal airways by providing a shorter intubation time and better laryngoscopic views compared with the Macintosh laryngoscope.

Indirect versus direct laryngoscopy for routine nasotracheal intubation

STUDY OBJECTIVE

To compare the effectiveness of the indirect laryngoscopes, Airtraq (A) and GlideScope (G), with the Macintosh (M) laryngoscope in routine nasotracheal intubation.

DESIGN

Randomized, single-blinded study.

SETTING

University-affiliated, tertiary-care hospital.

PATIENTS

62 adult, ASA physical status 1 and 2 patients with normal airways requiring nasotracheal intubation for dental or maxillofacial surgery.

INTERVENTION

Patients in Groups A and G underwent nasal intubation with the Airtraq and GlideScope, respectively, while laryngoscopy in Group M was performed with the Macintosh blade.

MEASUREMENTS

Performance of the intubating tools was judged by the ease [Intubation Difficulty Scale (IDS) and numeric rating scale (NRS)] and time to intubation (laryngoscopy and endotracheal tube advancement). In addition, hemodynamic parameters, severity of postoperative sore throat, and posture of the intubator were recorded.

MAIN RESULTS

IDS score was significantly lower with the Airtraq and GlideScope than with the Macintosh laryngoscope (mean ± SD: A 0.1 ± 0.3, G 0.3 ± 0.6, M 0.8 ± 1.0; P = 0.013). NRS reported by the intubators showed a similar preference for indirect over direct laryngoscopy (A 0.9 ± 0.7, G 1.1 ± 0.6, M 1.9 ± 1.1; P = 0.001). Duration of laryngoscopy and endotracheal tube insertion was similar in all groups. No significant intergroup differences in hemodynamic parameters were recorded. Postoperative sore throat was significantly reduced using the GlideScope compared with the other devices (P = 0.048).

CONCLUSION

The Airtraq and GlideScope facilitated nasotracheal intubation more so than the Macintosh laryngoscope in adults with apparently normal airways.

Reducing nasopharyngeal trauma: the urethral catheter-assisted nasotracheal intubation technique

Nasal intubation is an advantageous approach for dental procedures performed in the hospital, ambulatory surgery center, or dental office, when possible. Although many who provide anesthesia services are familiar and comfortable with nasal intubation techniques, some are reluctant and uncomfortable because of lack of experience or fear of nasopharyngeal bleeding and trauma. It has been observed from experiences in various settings that many approaches may be adapted to the technique of achieving nasal intubation. The technique that is described in this paper suggests a minimally invasive approach that introduces the nasoendotracheal tube through the nasopharyngeal pathway to the oropharynx in an expedient manner while preserving the nasopharyngeal structures, thus lessening nasal bleeding and trauma to soft tissues. The technique uses a common urethral catheter and can be incorporated along with current intubation armamentaria. As with all techniques, some limitations to the approach have been identified and are described in this paper. Cases with limited mouth opening, neck injury, and difficult airways may necessitate alternative methods. However, the short learning curve along with the many benefits of this technique offers the anesthesia professional additional options for excellent patient care.

Hemodynamic responses to tracheal intubation with the Glidescope videolaryngoscope: a comparison of oral and nasal routes

BACKGROUND

Although there have been numerous favorable reports on the uses of the GlideScope videolaryngoscope (GSVL) in oral and nasal intubations, no study has compared the hemodynamic responses to oral and nasal intubations with the GSVL in a single clinical trial. The purpose of this randomized clinical study was to determine whether there was a clinically relevant difference between the hemodynamic responses to oral and nasal intubations with the GSVL.

METHODS

A total of 71 patients, ASA physical status I, aged 18-50 years, scheduled for elective plastic surgery under general anesthesia, were randomly allocated to the oral intubation group (OI group) and the nasal intubation group (NI group). Noninvasive blood pressure (BP) and heart rate (HR) were recorded before (baseline values) and after anesthesia induction (postinduction values), at intubation and every minute for a further 5 minutes. Maximum values of BP and HR during the observation were noted. The product of HR and systolic blood pressure (rate pressure product, RPP), the percent changes of systolic blood pressure (SBP) and HR relative to the baseline values at every measuring point, and the areas under the SBP and HR versus time curves were calculated.

RESULTS

The intubation time was significantly longer in the NI group than in the OI group. The total incidence of difficulties encountered during laryngoscopy and intubation were higher in the OI group than in the NI group (29% vs. 6%, p < 0.05). BP at all measuring points, the maximum values of BP, the area under the SBP versus time curve, and the incidence of SBP percent increase more than 30% of baseline value did not differ significantly between the two groups. However, HR and RPP at intubation and their maximum values during the observation, the area under the HR versus time curve, and the incidence of HR percent increase more than 30% of baseline value were significantly higher in the OI group than in the NI group (p < 0.05). As compared with the NI group, the times required to reach the maximum values of SBP and HR were significantly shorter and the times required for recovery of SBP and HR to postinduction values were significantly longer in the OI group (p < 0.05).

CONCLUSION

In anesthetized adult patients, oral and nasal intubations with the GSVL can result in a similar pressor response. However, the tachycardic response to nasal intubation using a GSVL is smaller and of shorter duration than that to oral intubation using a GSVL.

The circulatory responses to tracheal intubation in children: a comparison of the oral and nasal routes

The circulatory responses to laryngoscopic tracheal intubation in 62 healthy children undergoing surgery requiring tracheal intubation were studied. They were randomly assigned to receive either the oral or nasal route for intubation. Baseline non-invasive blood pressure and heart rate were recorded following induction of anaesthesia, at intubation and then every minute for 5 min. The percentage changes of systolic blood pressure and heart rate during the measurement period were calculated. The results demonstrated that intubation time was significantly longer in the nasal group. Both oral and nasal intubation caused significant increases in blood pressure and heart rate compared to baseline and postinduction values. However, there were no significant differences found between the two groups in relation to blood pressure and heart rate. The two groups were similar with respect to the percentage changes of systolic blood pressure and heart rate during the observation period. It is concluded that oral and nasal intubation using a direct laryngoscopy can result in a similar circulatory response in anaesthetised children.

Circulatory responses to fiberoptic intubation in anesthetized children: a comparison of oral and nasal routes

BACKGROUND

Previous studies have demonstrated a significant difference in the circulatory responses in adults to fiberoptic nasotracheal intubation (FNI) and fiberoptic orotracheal intubation (FOI). But, it is unknown whether there is a clinically relevant difference in the circulatory responses in children to these two intubation methods.

METHODS

In this randomized clinical study, we compared the arterial blood pressure and heart rate changes during FNI and FOI in 66 children, ASA physical status I-II, aged 3-9 yr scheduled for elective plastic surgery. After anesthesia induction with fentanyl-propofol and vecuronium, fiberoptic intubation was performed. Noninvasive arterial blood pressure and heart rate were recorded before (baseline values) and after anesthesia induction (postinduction values), at intubation, and every minute for the first 5 min after intubation. The maximum values of arterial blood pressure and heart rate during the observation were also recorded.

RESULTS

The total intubation time was significantly longer in the FNI group than in the FOI group. Both FOI and FNI caused significant increases in arterial blood pressure and heart rate compared with the baseline and postinduction values. Arterial blood pressure and heart rate at intubation and after intubation, and their maximum values during the observed periods were significantly lower in the FNI group compared with the FOI group. The times required to reach the maximum values of systolic blood pressure and heart rate were significantly longer in the FNI group than in the FOI group, but the times required for recovery of systolic blood pressure and heart rate to postinduction values were significantly shorter in the FNI group than in the FOI group. After the intubation, the times required to reach the peak levels of systolic blood pressure and heart rate were not significantly different between the two groups.

CONCLUSIONS

Both FOI and FNI can cause significant circulatory responses in healthy anesthetized children, and the circulatory responses to FNI are fewer and of a shorter duration than those to FOI.

The circulatory responses to fibreoptic intubation: a comparison of oral and nasal routes

The circulatory responses to fibreoptic intubation under general anaesthesia were studied in 60 adult female patients who were randomly assigned to receive either the oral or nasal route for insertion. Non-invasive blood pressure and heart rate were recorded before anaesthesia induction (baseline values), immediately after anaesthesia induction (post-induction values), at intubation and every minute for a further 5 min. The product of heart rate and systolic blood pressure (rate pressure product) at every time point was also calculated. The results showed that both fibreoptic orotracheal intubation and fibreoptic nasotracheal intubation resulted in significant increases in blood pressure, heart rate and rate pressure product compared to baseline and post-induction values. The times required to reach the maximum values of systolic blood pressure and heart rate were significantly longer in the fibreoptic nasotracheal intubation group than in the fibreoptic orotracheal intubation group. There were no significant differences between the two groups in blood pressure, heart rate and rate pressure product at any measuring point, or in the maximum values during observation. The time required for recovery of systolic blood pressure to the post-induction value was not significantly different between the two groups, but the time required for recovery of heart rate to post-induction value was significantly longer in the fibreoptic orotracheal intubation group than in the fibreoptic nasotracheal intubation group. It was concluded that both fibreoptic orotracheal and fibreoptic nasotracheal intubations could cause a similar magnitude of circulatory responses in general anaesthetised, female adults, but the tachycardic response to fibreoptic orotracheal intubation lasted longer than that to fibreoptic nasotracheal intubation.