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Validity of rhinometry in measuring nasal patency for nasotracheal intubtion
Abstract
PurposeNumerous techniques have been used to reduce epistaxis during nasotracheal intubation. Rhinometry can assess nasal patency in preoperative conditions. However, the possible role of rhinometry in routine nasotracheal intubation has not been studied. Methods
One hundred and one patients undergoing dental and maxillofacial surgery that required general anesthesia and nasotracheal intubation were enrolled. We examined whether symmetry or any asymmetry in bilateral airflow patterns by condensation of the expiration, assessed by preoperative rhinometry on seated position, increased the incidence of epistaxis and the need for a nasogastric catheter to guide the endotracheal tube into the oropharynx. We also compared the incidence of changing the site of nasal intubation between the assessment by rhinometry and by cone-beam computed tomography analysis of nasal airspace in the inferior meatus. ResultsPatients with any asymmetry in bilateral airflow patterns were 18 % (n = 18), the remaining 82 % (n = 83) had symmetric bilateral nasal cavities. Patients with any asymmetry were more likely to need a guiding nasogastric catheter than patients with symmetry (22 vs. 3.6 %, p = 0.018). The incidence of epistaxis was higher in patients with any asymmetry (39 %) than those with symmetry (16 %), but there was no significant difference between groups (p = 0.055). The site of intubation was changed more frequently based on cone-beam computed tomography analysis than by rhinometry (38 vs. 11 %, p = 0.043). Conclusion
Preoperative rhinometry may be a valuable objective tool to assess nasal patency for nasotracheal intubation in patients who undergo dental and maxillofacial surgery.
... Nasotracheal intubation should be performed based on the overall results of preoperative evaluation. If nasotracheal KSAM intubation is expected to be difficult, a discussion should be conducted with the surgeon to decide whether to perform nasotracheal intubation or not and to devise alternative methods [21,22]. The pre-anesthetic evaluation for these patients should be performed within 48 h before surgery and should be documented and recorded [2][3][4][5][6]. ...
... Using a tube with a cuff requires attention to the cuff pressure. When the cuff pressure reaches 30 cmH2O, the tracheal mucosal blood flow is compromised, and when the cuff pressure reaches 45 cmH2O, the mucosal blood flow is completely obstructed [21]. It has been reported that tube lubrication with K-Y jelly (Johnson & Johnson, USA) inhibits the increase in cuff pressure in vitro when using a tube with a cuff under general anesthesia using N2O. ...
Nasotracheal intubation is used as a basic method for airway management, along with orotracheal intubation under anesthesia and intensive care. It has become an effective alternative method to orotracheal intubation with increased benefits of offering better mobility and surgical field in oral and maxillofacial surgery and possibly in trauma and critically ill patients. Nasotracheal intubation is performed through a relatively narrow nasal cavity; therefore, additional precautions are needed. Accordingly, nasotracheal intubation methods have evolved over the years with accumulated clinical experience and improved instruments to facilitate safe intubation with reduced complications. Therefore, in this review article, we summarize the basic anatomy of the nasal airways to clarify the precautions, delineate the history and development of various methods and instruments, and describe the indications, contraindications, complications, and preventive methods of nasotracheal intubation.
... Gogniashvili et al. also investigated the nasal cycle in the same manner [6]. In general anesthesia, nasal patency is investigated before nasal intubation [7]. Rhinomanometry can measure nasal resistance during the nasal cycle; however, it cannot measure the direct airflow pressure in the nasal cavity. ...
Objective:
Previously, we used a nasal cavity model to analyze the intranasal airflow dynamics and numerically calculate the nasal resistance value. In this study, We attempted clarify the parameters influencing nasal resistance by newly developed computer model.
Methods:
The computer simulation model was developed from the structures of nasal airway tract adopted from 1.0-mm slice computed tomography (CT) obtained from the 2 of the healthy volunteers. (model 1: the one at 35-year-old man, model 2: 25-year-old man.) We have calculated the nasal resistance by computer simulation calculations of both model 1 and model 2. These calculated values were compared with the values obtained from the established method of rhinomanometry. For the simulation, Fluent 17.2® (ANSYS, American) was employed for f luid a nalysis u sing the continuity equation for 3D incompressible flow and the Navies-Stokes equation for the basic equations. Both models were laminar models. The SIMPLE calculation method using the finite volume method was employed here, and the quadratic precision upwind difference method was used to discretize the convection terms.
Results:
The measured (simulation) values in Model 1 were 0.69 (0.48), 1.10 (0.41), and 0.42 (0.22) Pa/cm3/s on the right, left, and both sides, whereas those in Model 2 were 0.72 (0.21), 0.32 (0.09), and 0.22 (0.06) Pa/cm3/s, respectively.
Conclusion:
Our results suggest that nasal resistance is possibly affected by the length of the inferior turbinate and the cross-sectional area of the choana and nasopharynx. Further experiments using additional nasal cavity and paranasal sinus models are warranted.
... Determining the appropriate nasal cavity before nasal intubation as part of the preoperative evaluation is critical to minimizing potential complications. Nasal endoscopy, and rhinological evaluations, separately or together, were recommended for this purpose in the literature [12][13][14][15][16]. In our department, nasal intubation is performed from the side recommended by the ENT department for the patients for whom ENT consultation is requested. ...
In this study, we aimed to share our experience in preoperative anaesthesia evaluation for patients undergoing bimaxillary surgery in our hospital and review the relevant literature. We retrospectively evaluated 139 patients with ASA (American Society of Anesthesiology) physical status 1 and 2 who underwent bimaxillary surgery. Data were collected on demographic characteristics, ASA physical status, mallampati scores, systemic diseases, allergy history, consultation request status, consulted departments, smoking, alcohol or drug use, and previous exposure to general anaesthesia. The preoperative evaluation of bimaxillary surgery patients revealed several notable findings, including a relatively high rate of cardiovascular problems (48% rate among those with additional systemic disease), the need for otolaryngology (ENT) consultation being the most frequent (44% rate among all consultations), and a relatively high rate of active smoking (23.7%). Our findings suggest that the bimaxillary surgery patient group should be carefully evaluated, particularly regarding cardiovascular disease and difficult airway management
... Which ranges from blood-soaked mucus to large and extensive hemorrhages. [4,9] Although the amount of bleeding usually is not problematic for the patient or the surgical procedure, sometimes life-threatening bleeding has been reported. [10] Blood in the airways will interfere with the doctor's vision and there is even the possibility of aspiration of blood into the lungs. ...
Background:
Different techniques have been introduced to reduce the complications of nasotracheal intubation. The aim of this study was to compare the incidence of nasotracheal intubation complications in finger-guided and conventional methods.
Materials and methods:
In this double-blind randomized trial study, 70 patients who were candidates for oral and maxillofacial surgery who required nasal intubation were included in the study finally of which 33 patients with conventional method and 35 patients with finger-guided tubes in the nasopharynx were analyzed at the end of the study. Variables such as success rate, hemodynamic response, and complications of intubation were compared between the two groups.
Results:
There was no significant difference between the two groups in terms of hemodynamic response to intubation (P > 0.05). There was a significant difference between the two groups in terms of success in tracheal intubation (P < 0.05). There was a significant difference between the two groups in terms of epistaxis immediately after intubation (P < 0.05). There was no significant difference between the two groups in terms of nasal turbine fractures (P > 0.05). However, the frequency of submucosal intubation in the conventional method was significantly higher than the other group (P = 0.02).
Conclusion:
Nasotracheal intubation using the finger guiding technique in the nasopharynx is associated with a higher success rate and less complications after intubation such as epistaxis and submucosal intubation compared to the conventional method.
... Determining the appropriate nasal cavity before nasal intubation as a part of the preoperative evaluation is a critical approach to minimizing the complications that might arise, and nasal endoscopy, and rhinological evaluations, separately or together, were recommended for this purpose in the literature [19][20][21][22][23]. Among rhinological evaluations, rhinomanometric and rhinometric measurements were recommended as objective methods that evaluate nasal obstruction especially. ...
Purpose: To evaluate the effectiveness of Computed tomography-guided nasotracheal intubation in predicting tube advancement difficulty and preventing epistaxis.
Material and Methods: Sixty maxillofacial surgery patients were included in the study. The space where the tube will be passed in the internal nasal valve region was measured horizontally and vertically by Computed Tomography. The same experienced anesthesiologist intubated all patients. The patients were divided into two groups, 'easy' (n=28) or 'difficult' (n=32), according to the effort required to advance the tube through the nasal passage.
Results: The measured median distances were shorter in a difficult group than in the easy group (p<0.001). Epistaxis was significantly higher in the difficult group (p<0.001). Epistaxis was considerably higher in the difficult group (p<0.001).
ROC analysis was performed, and cut-off values were determined to reveal the distance values at which difficulty may be experienced while advancing the tube. The cut-off values were 1.09 cm and 0.39 cm for the vertical and horizontal distances, respectively.
Conclusion: It was concluded that taking into account the measurements obtained from the tomography scan was a convenient way to estimate the difficulty of advancing the tube and thus avoid nosebleeds encountered during nasal intubation.
... e main type of EEG in the early epilepsy group was type iii. Relevant clinical research reports [15] that in the case of acute pathological damage to the cerebral cortex, electrolyte, neuronal ischemia, acid-base balance disorder, and hypoxia will be accompanied, which will greatly affect the stability of neuron cells, and obvious depolarization will further affect the activity of cortical neurons [16]. When the electrical activity spreads to the adjacent tissues, it will stimulate the thalamus greatly and produce an excitatory transient postsynaptic potential, which will then activate the distal or adjacent neuron groups and significantly change the neural network [17]. ...
Objective:
To search the predictive value of epilepsy secondary to acute subarachnoid hemorrhage (aSAH) based on EEG wave pattern in deep learning.
Methods:
A total of 156 cases of secondary epilepsy with lower cavity hemorrhage in our hospital were selected and divided into the late epilepsy group and the early epilepsy group according to seizure time, and the nonseizure group and the seizure group according to seizure condition. General data of patients were collected, the EEG types of each group were analyzed, and the disease recurrence rate, treatment effect, and symptom onset time were compared.
Results:
Rapid and slow and rapid blood flow velocity were the main abnormal manifestations of epilepsy secondary to inferior cavity hemorrhage, accounting for 33.3% and 18.6%, respectively. Compared with the seizure group, the proportion of type ii and type iii in the nonseizure group was higher, and the proportion of type ii and type iii in the early epilepsy group was higher than in the late epilepsy group (P < 0.05). The diagnostic accuracy, missed diagnosis rate, misdiagnosis rate, specificity, and sensitivity of the EEG wave pattern were 94.9%, 3.2%, 1.9%, 91.7%, and 96.2%, respectively. Compared with the early epilepsy group, the recurrence rate of type iii and type iv in the late epilepsy group was higher (P < 0.05). The effective rates of the attack group and the nonattack group were 72.7% and 97.0%, respectively. Compared with the attack group, the effective rate of the nonattack group was higher (P < 0.05). The effective rates of the early epilepsy group and the late epilepsy group were 91.7% and 85.0%, respectively. Compared with the late epilepsy group, the effective rate of the early epilepsy group was higher (P < 0.05). Compared with the early epilepsy group, the late epilepsy group had longer tonic-clonic seizures, atonic seizures, and absent seizures, and the difference between the groups was statistically significant (P < 0.05).
Conclusion:
In aSAH secondary epilepsy disease prediction, based on indepth study of the scalp EEG wave type prediction, they play an important role, including aSAH high-risk secondary epilepsy wave types for V, III, and IV types, as well as early and late epilepsy associated with disease stage. Through the diagnosis method to predict the severity of disease, this builds a good foundation for clinical treatment. It is beneficial to improve the effective rate of treatment.
... Furthermore, the patency of the nostril is a very important factor in reducing injury to nasal passages. Recently, rhinomanometry has been introduced to evaluate the patency of nostrils [13][14][15]. However, this method is not commonly used in clinical practice because it is not simple and requires special equipment; thus, simpler techniques are preferred. ...
Background
Nasotracheal intubation is a blind procedure that may lead to complications; therefore, several tests were introduced to assess a suitable nostril for nasotracheal intubation. However, the value of simple tests in clinical practice was insufficient to evaluate.
Method
A diagnostic prospective study was conducted in 42 patients, ASA classes I–III, undergoing surgery requiring nasotracheal intubation for general anesthesia. Two simple methods for assessing the patency of nostrils were investigated. Firstly, the occlusion test was evaluated by asking for the patient's own assessment of nasal airflow during occlusion of each contralateral nostril while in a sitting posture. Secondly, patients breathed onto a spatula held 1 cm below the nostrils while in a sitting posture. All patients were assessed using these two simple tests. Nasal endoscopic examination of each patient was used as a gold standard.
Results
The diagnostic value of the occlusion test (sensitivity of 91.7%, specificity of 61.1%, PPV of 75.9%, NPV of 84.6%, LR+ of 2.36, and LR− of 0.14) seemed better than that of the spatula test (sensitivity of 95.8%, specificity of 25.0%, PPV of 63.0%, NPV of 81.8%, LR+ of 1.28, and LR− of 0.17). When both tests were combined in series, the diagnostic value increased (sensitivity of 87.9%, specificity of 70.8%, PPV of 80.1%, NPV of 81.4%, LR+ of 3.01, and LR− of 0.17).
Conclusion and Recommendations
The simple occlusion test is more useful than the spatula test. However, combining the results from both tests in series helped to improve the diagnostic value for selecting a suitable nostril for nasotracheal intubation.
Background and Aims
Nasal endoscopy, an objective technique for precisely identifying a clearer nasal cavity (NC), has limited clinical utility due to its invasive nature. Nasal magnetic resonance imaging (MRI) can be a reliable, non-invasive, objective alternative to nasal endoscopy. Hence, this study was planned to find the efficacy of MRI compared to nasal endoscopy in identifying a clearer NC.
Methods
In this randomised study, patients between 18 and 75 years were enroled to identify a clearer NC by nasal endoscopy and MRI. One hundred and forty patients were randomised between the nasal endoscopy or MRI groups for nasotracheal intubation through MRI or nasal endoscopy and identified as having a clearer NC. To assess the successful tube negotiation through the MRI or nasal endoscopy identified clearer NC, an agreement between the nasal endoscopy and MRI assigned clearer NC with the ultimate NC of tube negotiation was evaluated using Cohen’s kappa interrater agreement with linear weights test.
Results
We found excellent agreement between the MRI and nasal endoscopy for identifying clearer nasal cavities [κ = 0.91, 95% confidence interval (CI): 0.80, 0.96]. Similarly, excellent agreement was found between the MRI (κ = 0.88, 95% CI: 0.80, 0.96) or nasal endoscopy (κ = 0.88, 95% CI: 0.80, 0.96) identified clearer NC and the NC through which the tube was ultimately negotiated.
Conclusion
MRI is an objective and reliable alternative to nasal endoscopy for NC assessment. It precisely identifies nasal anomalies and selects a wider and clearer NC.
Objectives:
To evaluate the effectiveness of computed tomography-guided nasotracheal intubation procedure in predicting tube advancement difficulty and preventing epistaxis.
Methods:
The prospective study was conducted at Erciyes University Faculty of Dentistry from April 2018 to June 2019 and comprised maxillofacial surgery patients of either gender aged 18-50 years who were due to undergo bimaxillary orthognathic surgery, which was defined as American Society of Anaesthesiology grade I or II. The space where the tube was to be passed in the internal nasal valve region was measured horizontally and vertically using computed tomography. A single experienced anaesthesiologists intubated all the patients who were later divided into 'easy' group A and 'difficult' group B on the basis of the effort required to advance the tube through the nasal passage. Data was analysed using JASP version 0.14.1.0).
Results:
Of the 60 patients, 42(70%) were females and 18(30%) were males. The overall mean age was 29.0±10.5 years and the mean body mass index value was 23.6±4.0 kg/m 2 (p>0.05). There were 28(46.6%) patients in group A, and 32(53.3%) in group B. Median distances were significantly shorter and epistaxis was significantly higher in group B compared to group A (p<0.001). The cut-off values to reveal the distance at which difficulty may be experienced while advancing the tube, determined through receiver operating characteristic analysis, were 1.09 cm for vertical and 0.39cm for horizontal distances.
Conclusions:
The nasotracheal intubation procedure under the guidance of computed tomography could help predict the difficulty of tube advancement, and could thus prevent epistaxis and other related nasal intubation complications. Clinical trial number: NCT05525754.
Objective
Dexmedetomidine, an α2-adrenergic receptor agonist, mitigates cognitive dysfunction in elderly patients after surgery with general anesthesia. However, the underlying mechanism by which dexmedetomidine reduces cognitive dysfunction remains to be fully elucidated. The aim of this study was to investigate the effects of dexmedetomidine on lipopolysaccharide (LPS)-induced neuronal dysfunction in cultured hippocampal neurons.
Methods
LPS, in the presence and absence of dexmedetomidine, was applied to cultured hippocampal neurons to mimic post-surgical inflammation. Neuronal morphology, including neurite outgrowth and synaptic transmission, was observed, and miniature excitatory postsynaptic currents were recorded by electrophysiological patch-clamp.
Results
LPS significantly impaired neurite outgrowth in hippocampal neurons in a concentration- and time-dependent manner, which was reversed by dexmedetomidine treatment. Electrophysiological patch-clamp results showed that LPS induced synaptic transmission dysfunction, which was restored after dexmedetomidine addition. Furthermore, Western blotting assays showed that LPS suppressed the AKT/GSK-3β/CRMP-2 signaling pathway and dexmedetomidine countered the inhibitory effect of LPS by re-activating this pathway.
Conclusion
In general, dexmedetomidine protected against the effects of LPS-induced hippocampal neuron damage, including neurite outgrowth and synaptic transmission. Overall, dexmedetomidine modulated the AKT/GSK-3β/CRMP-2 signaling pathway to alleviate LPS-induced neurological dysfunction.
The COVID-19 pandemic has posed new challenges to the anesthesiologists the world over. Keeping in mind the way the virus was known to be spreading through aerosols and the global deficiency of personal protective equipment, medical workers embarked upon to create and develop devices and equipment to protect themselves from the virus during this pandemic period.
Taiwanese anesthesiologist Dr. Hsien Yung Lai has constructed an aerosol box,1 whose function is to offer an additional protection from aerosols produced during the induction and intubation of the patients needing surgery. The box is transparent made of plexiglass with dimensions of 50 x 50 x 40 cm. The box has two holes with diameters of 10 cm each, for insertion and manipulation of the hands of the intubating anesthesiologist.
Taking consideration of the recommendations for COVID-19 by The European Society of Regional Anaesthesia & Pain Therapy (ESRA) and The American Society of Regional Anesthesia and Pain Medicine (ASRA).2 the preference is given to peripheral nerve blocks as a main anesthesia technique, thus avoiding the need of intubation and general anesthesia.
We used the aerosol box as a protective shield for performing peripheral nerve blocks of brachial plexus, by infraclavicular and interscalene approach and cervical plexus block in patients who were suspected of CoViD-19 infection. Many studies concluded that the potential aerosol spread of SARS-CoV-2 is not only through coughing and sneezing, but also through breathing.3 In a large number of these patients, a cough is a symptom which represents a high possibility of transmitting the virus through aerosols to the anesthesiologist, because of the close contact that they have during the performance of these blocks.
The box is positioned over the patient's head. Through the one hole, the anesthesiologist inserts one hand with the needle for applying the peripheral nerve block; through the other hole, the other hand holds the probe of the ultrasound. During the procedure, the anesthesiologist is using the recommended PPE.
Although the space is limited for manipulation, we successfully performed the blocks without much limitations.
We think that the use of aerosol box during manipulation and performing the peripheral nerve blocks in brachial and cervical region, in patients that are suspected of COVID-19, or are known to be infected, enhances the safety of the anesthesiologist as the chances of infection during the manipulation are extremely low.
This EAACI Task Force document aims at providing the readers with a comprehensive and complete overview of the currently available tools for diagnosis of nasal and sino-nasal disease. We have tried to logically order the different important issues related to history taking, clinical examination and additional investigative tools for evaluation of the severity of sinonasal disease into a consensus document. A panel of European experts in the field of Rhinology has contributed to this consensus document on Diagnostic Tools in Rhinology.
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.
The placement of endotracheal tubes in the airway, particularly through the nose, can cause trauma. Their design might be an important etiologic factor, but they have changed little since their introduction. Recently Parker Medical (Bridgewater, Conn) introduced the Parker Flex-Tip (PFT) tube, suggesting that it causes less trauma. This study aimed to compare the PFT endotracheal tube to a side-beveled, standard-tip endotracheal tube (ETT) for nasotracheal intubation (Figures 1 and 2). Forty consecutive oral surgery patients requiring nasotracheal intubation were randomized to receive either a standard ETT or the PFT tube. Intubations were recorded using a fiber-optic camera positioned proximal to the Murphy eye of the tube. This allowed visualization of the path and action of the tube tip as it traversed the nasal, pharyngeal, laryngeal, and tracheal airway regions. Video recordings made during intubation and extubation were evaluated for bleeding, trauma, and intubation time. Both bleeding and trauma were recorded using a visual analogue scale (VAS) and by 3 different evaluators. The PFT received significantly better VAS values than the standard tubes from all 3 raters (P < 0.05) in both the extent of trauma and bleeding. Since the intubations were purposefully conducted slowly for photographic reasons, neither tube displayed a time advantage. This study suggests that the PFT tube design may be safer by causing less trauma and bleeding than standard tube designs for nasotracheal intubation.
This review describes the phenomenon of the nasal cycle, which consists of periodic congestion and decongestion of the nasal venous sinusoids. The hypothesis is put forward that the nasal venous sinusoids participate in respiratory defence by generation of plasma exudate. This hypothesis is based on recent studies, which have shown that the nasal venous sinusoids have a fenestrated endothelium and that the nasal cycle is increased during periods of nasal infection; and also on a series of older observations in the literature, which link the generation of nasal fluid to the decongestion of nasal venous sinusoids. It is proposed that the periodic congestion and decongestion of nasal venous sinusoids may provide a pump mechanism for the generation of plasma exudate, and that this mechanism is an important component of respiratory defence.
Nasotracheal intubation (NTI) has greater potential for trauma of nasopharyngeal mucosa than orotracheal intubation. The present study investigated the success rate of NTI and frequency of nasal bleeding using a curve-tipped suction catheter (CTSC) to guide nasotracheal tube advancement.
Subjects comprised 131 adult patients who under-went NTI. Subjects were randomly divided into two groups: a) NTI under CTSC guidance (G[+] group). The CTSC (14 Fr) was first inserted through the tracheal tube, with the tip of the CTSC emerging from the distal end of the tube. The curved tip was directed ventrally. Both tracheal tube and CTSC were advanced together through the nasopharynx; b) NTI without CTSC guidance (G[-] group). The tracheal tube was advanced into the nasal cavity and passed into the pharynx without CTSC guidance. The time required to pass the endotracheal tube through the nasal cavity (nasal passage time), success rate of nasal passage with nasotracheal tube, and the incidence and severity of nasal bleeding were compared.
Success rate for nasal passage was 100% in the G(+) group (62/62) and 82.6% in the G(-) group (57/69; P = 0.0006). Frequency of nasal bleeding was significantly lower in the G(+) group (21/62, 33.9%) than in the G(-) group (37/69, 53.6%; P = 0.023). Severity of nasal bleeding was also significantly lower in the G(+) group than in the G(-) group (P = 0.030).
Nasotracheal intubation under CTSC guidance increases the success rate of airway instrumentation, and also reduces the incidence and severity of epistaxis.
In nasotracheal intubation, there are two main pathways in the nostril through which the endotracheal tube may pass. The lower pathway lies along the floor of the nose underneath the inferior turbinate. The upper pathway lies above the inferior turbinate, just below the middle turbinate. The lower pathway may be considered to be the safer route as it is located away from the middle turbinate and cribiform plate.
We conducted a randomized controlled trial comparing the frequency with which preformed, reinforced, and thermosoftened preformed tubes pass through upper and lower pathways. Ninety-two maxillofacial patients requiring nasotracheal intubation as part of their anaesthetic management were studied. Two patients were excluded from the study at endoscopy because of atypical nasal anatomy. After the induction of general anaesthesia, a standardized traditional nasal intubation was performed with a Macintosh laryngoscope, the operators endeavouring to direct the tube along the floor of the nose. Fibreoptic nasendoscopy was then performed by passing the tip of the fibrescope 2-3 cm into the nasal cavity above and below the tube, to identify the pathway taken.
Data were analysed on 30 patients in each group. Five (16.7%) preformed tubes, 17 (56.7%) reinforced tubes, and 6 (20%) thermosoftened preformed tubes passed through the lower pathway. Significantly more reinforced tubes took the preferred pathway (P=0.001). Tubes passing through the upper pathway caused significantly more epistaxis than tubes passing through the lower pathway (P=0.003).
Endotracheal tubes, particularly preformed tubes, frequently take the less favourable pathway during nasotracheal intubation, in spite of specific attempts to avoid this.
During nasotracheal intubation, the tracheal tube passes through either the upper or lower pathway in the nasal cavity, and it has been reported to be safer that the tracheal tube passes though the lower pathway, just below the inferior turbinate. We evaluated the use of a nasogastric tube as a guide to facilitate tracheal tube passage through the lower pathway, compared with the ‘conventional’ technique (blind insertion of the tracheal tube into the nasal cavity). A total of 60 adult patients undergoing oral and maxillofacial surgery were included in the study. In 20 out of 30 patients (66.7%) with the nasogastric tube-guided technique, the tracheal tube passed through the lower pathway, compared with 8 out of 30 patients (26.7%) with the ‘conventional’ technique (p = 0.004). Use of the nasogastric tube-guided technique reduced the incidence and severity of epistaxis (p = 0.027), improved navigability (p = 0.034) and required fewer manipulations (p = 0.001) than the ‘conventional’ technique.
To evaluate the reliability of assessments of nasal flow rate for improved nostril selection for nasotracheal intubation.
Prospective, randomized, double-blinded study.
Operating room of a university-affiliated hospital.
118 ASA physical status 1 and 2 patients, aged 18-65 years, scheduled for elective maxillofacial and oral surgery requiring nasotracheal intubation.
Patients were randomized to the left or right nostril groups. Forced vital capacity (FVC) and forced expiratory volume in one second (FEV(1)) through the mouth and each nostril were measured before anesthesia induction.
The relationship between the rate of airflow through the selected nostril and frequency of epistaxis and navigability of the nasotracheal tube were evaluated.
There were no significant differences in the frequency of epistaxis and degree of navigability of the tracheal tube between the left and right nostril groups. In both nostril groups, patients who suffered epistaxis showed significantly less FEV(1) and FEV(1)/FVC values than did patients without epistaxis (P < 0.05). In addition, in both groups patients who passed the tube easily showed significantly higher FEV(1) and FEV(1)/FVC values than did patients who passed the tube with resistance or failed tube passage (P < 0.05).
Measurement of nasal flow rate is a useful clinical method for choosing a nostril for nasotracheal intubation.
We tested our hypothesis that use of the Parker Flex-Tip tracheal tube could reduce the incidence of nasal mucosal trauma during nasotracheal intubation when compared with a conventional tip tracheal tube. One hundred and two patients, who were scheduled for elective oral surgery in which nasotracheal intubation was indicated to optimise the surgical approach, were recruited into this study. Either a Flex-Tip tracheal tube or a conventional tip tracheal tube was chosen randomly for each nasotracheal intubation. The incidence of epistaxis using the Flex-Tip tracheal tube (6 (11.8%)) was significantly lower than that with the conventional tip tracheal tube (18 (35.3%); p = 0.009). Nasal pain due to intubation, rated on a 100-mm visual analogue scale, was less intense with the Flex-Tip tracheal tube (median, (10th-90th percentile) 19 (12-28) mm compared with the conventional tip tracheal tube (30 (22-35) mm; p < 0.001). The Flex-Tip tracheal tube thus appeared to reduce the incidence of nasal mucosal trauma during nasotracheal intubation and the incidence of post-intubation nasal pain, compared with the conventional tip tracheal tube.
The alternating congestion and decongestion of the nasal mucosa, termed the "nasal cycle", was investigated with current mask (posterior) active rhinomanometric techniques. This communication reports variations in nasal resistance in 50 human subjects, each studied for about 7 hours. Approximately 600 resistance values (cm H2O/liter per second) were obtained from each subject. The nasal cycle defined in rhinomanometric terms was that alternating congestion and decongestion of the nasal turbinates which produced a change in pressure and airflow values calculated as resistance (comparing one side with the other) of 20% or greater for two consecutive observations (at least 15 minutes). The data demonstrated that 36 of 50 subjects (12 of 18 males and 24 of 32 females) had at least one nasal cycle during the period of observation.
We have studied the prevalence of intranasal abnormalities that may influence the choice of nostril for intubation, using
the fibreoptic laryngoscope, in 60 oral surgery patients presenting for nasotracheal intubation under general anaesthesia,
who had no symptoms or signs of nasal obstruction. Videotape recordings were made during each nasendoscopy and later analysed
by an anaesthetist and an otolaryngologist. A total of 68% of patients had intranasal abnormalities (10% bilateral and 58%
unilateral) which resulted in one nostril being more patent than the other and therefore considered more suitable for intubation.
The most common abnormality was deviated nasal septum which occurred in 57% of the study group; 22% were minor deviations,
13% were major deviations and 22% were impactions. Other abnormalities were simple spurs, unilateral polyp and hypertrophy
of the inferior turbinate. In view of the relatively high incidence of intranasal pathology revealed on endoscopic examination,
anaesthetists should consider using the fibreoptic laryngoscope to select the best nostril when performing nasotracheal intubation.
We have studied the reliability of two simple pre-induction tests used to select the more patent nostril for nasotracheal intubation by comparing their results with those obtained from fibreoptic examination of the nostrils, in 75 maxillo-facial patients requiring nasotracheal intubation under general anaesthesia, who had no history of nasal obstruction. The tests comprised (1) estimation of the rate of airflow through each nostril during expiration by palpating the passage of air when the contralateral nostril was occluded, and (2) asking for the patient's assessment of airflow through the nostrils, following the administration of a vasoconstrictor. After each test, noses were classified as left or right nostril clearer or nostrils equally clear. After the induction of general anaesthesia, bilateral nasendoscopies were performed and videotape recordings of these were later analysed by an otolaryngologist who had no knowledge of the test results. Intranasal abnormalities were identified and noses were again classified as left or right nostril clearer or nostrils equally clear. There was no significant difference between the overall diagnostic success rates of the two tests (44% and 47%, respectively). In patients with intranasal abnormalities, the numbers of correct diagnoses made by the two tests were not significantly different and were also not significantly different from the number of correct selections made if only the right nostril or only the left nostril had been used for the intubation. In view of the relatively high diagnostic failure rates, anaesthetists should not rely on the two tests investigated when selecting the best nostril for nasotracheal intubation.
Nasal spirometry has been used previously to monitor the nasal cycle. Asymmetry of nasal airflow is expressed as a nasal partitioning ratio (NPR) that ranges from -1 (left nasal cavity obstruction) to + (right nasal cavity obstruction) with 0 indicating symmetry of airflow. This study investigated the normal range of NPR in the decongested nose as a means of assessing the degree of nasal septal deviation.
NPR was measured in 100 healthy volunteers using a portable spirometer.
Mean NPR before decongestion was -0.1 +/- 0.32 SD (range, -0.84-0.75), and after decongestion mean NPR was -0.02 +/- 0.16 SD (range, -0.46-0.51). Male NPR ranged from -0.46 to 0.51 (mean, -0.1 +/- 0.22) whereas female NPR was from -0.21 to 0.37 (mean, -0.03 +/- 0.1; p < 0.001). There was a significant correlation between the clinicians assessment of the degree of septal deviation and NPR, r(s) = 0.69 (p < 0.01). The 95% reference range for NPR in this normal population was found to be between +0.30 and -0.34.
A normal range of NPR may prove useful in assessing patients complaining of nasal obstruction. A case may be made that patients on the waiting list that fall within the normal range of NPR are unlikely to benefit from septal surgery because their nasal passages are not greatly asymmetrical.
Epistaxis is the most common complication of nasotracheal intubation. We compared endotracheal tubes (ETT) obturated with an inflated esophageal stethoscope with normal ETTs with regard to the prevention of epistaxis and navigability, both with and without thermosoftening.
Dental surgical patients requiring nasotracheal intubation were randomly allocated into 1 of 4 groups (n = 50 each): Group 1, nonthermosoftened ETTs; Group 2, nonthermosoftened ETTs obturated with an inflated esophageal stethoscope; Group 3, thermosoftened ETTs; and Group 4, thermosoftened ETTs obturated with an inflated esophageal stethoscope. Navigability of ETTs through the nasal cavity and postintubation epistaxis were evaluated.
Navigability of ETTs through the nasal cavity was the worst in Group 1 (P = 0.001). Epistaxis was the most severe in Group 1, similar between Groups 2 and 3, and the least severe in Group 4 (P < 0.001).
The use of esophageal stethoscope-obturated ETTs was effective, and comparable to thermosoftening, in preventing epistaxis associated with nasotracheal intubation. Thermosoftened, obturated ETTs were more effective than simple thermosoftened ETTs in reducing epistaxis.
Thermosoftening treatment of the nasotracheal tube before intubation can reduce epistaxis and nasal damage
- Y C Kim
- S H Lee
- G J Noh
- S Y Cho
- J H Yeom
- W J Shin
- D H Lee
- J S Ryu
- Y S Park
- K J Cha
- S C Lee
- YC Kim
Usefulness and problems of transnasal gastrointestinal endoscopy
- T Kojima
- S Tsukamoto
- H Ikegaya
- T Aoki
- N Ooba
- S Nishinakagawa
- Y Mizuguchi