Blind nasotracheal intubation in awaken patient scheduled for hemimandibulectomy: case report

Abstracts

JUSTIFICATIVA E OBJETIVOS: A abordagem à via aérea pode utilizar diversos recursos. Manter o paciente acordado, cujo controle seguro da ventilação/oxigenação é incerto, constitui uma opção quando há dúvida quanto à intubação. A intubação nasotraqueal (INT) às cegas é uma alternativa à fibroscopia. RELATO DO CASO: Paciente do sexo feminino, 75 anos, 56 kg, candidata à hemimandibulectomia, com imobilidade cervical por artrodese, abertura bucal de 2,2 cm, retrognatismo moderado, sem protrusão voluntária da mandíbula, distância mento-esternal de 11 cm e mento-tireoidiana de 6 cm, recebendo 5 pontos na escala Wilson. A paciente previamente orientada consentiu com o procedimento. Após monitoração e oxigenação, foi iniciada infusão contínua de dexmedetomidina. Realizado bloqueio dos nervos laríngeo superior e inferior com lidocaína a 2,0% sem vasoconstritor e instilação de lidocaína spray em hipofaringe. Previamente à INT foram administrados ondansetron, midazolam, fentanil e droperidol, permanecendo a paciente acordada e cooperativa. A inserção via nasal de tubo traqueal foi orientada pela sua opacificação e ruídos respiratórios e confirmada por ausculta pulmonar e capnografia. Iniciada infusão contínua de propofol e remifentanil, administrados rocurônio e ventilação controlada. A operação de 60 minutos não teve intercorrências. Ao término, a paciente apresentava ventilação espontânea, sendo extubada e encaminhada à recuperação pós-anestésica, recebendo alta sem queixas. CONCLUSÕES: A INT é alternativa à fibroscopia quando a segurança do controle das vias aéreas é incerta. O prévio esclarecimento da paciente foi essencial. Houve segurança, sem depressão respiratória ou instabilidade hemodinâmica.

ANESTESIA, geral; INTUBAÇÃO: nasotraqueal, às cegas

CLINICAL REPORT

Blind nasotracheal intubation in awaken patient scheduled for hemimandibulectomy. Case report^*

Intubación nasotraqueal a ciegas en paciente despierta candidata a la hemimandibulectomía. Relato de caso

Daniel de Carli, TSA^I; Nivaldo Simões Correa, TSA^II; Tatiana Castelo Branco Vilar Silva^III; Eduardo Malta Maradei^IV

^IInstrutor Co-Responsável pelo CET do Hospital Vera Cruz; Professor Colaborador da Disciplina de Anestesiologia da Faculdade de Medicina de Jundiaí; Membro do Corpo Clínico do Hospital Paulo Sacramento, Jundiaí, SP

^IIInstrutor Co-Responsável pelo CET do Hospital Vera Cruz

^IIIME₃ do CET Hospital Vera Cruz

^IVME₂ do CET Hospital Vera Cruz

^{Correspondence to}

SUMMARY

BACKGROUND AND OBJECTIVES: Several resources can be used for the approach of the airways. Maintaining a patient awake when control of ventilation/oxygenation is uncertain is an option when intubation is doubtful. Blind nasotracheal intubation (NTI) is an alternative to fiberoptic endoscopy.

CASE REPORT: A 75-year old patient, weighing 56 kg, was scheduled for hemimandibulectomy; she presented cervical immobility secondary to arthrodesis, mouth opening of 2.2 cm, moderate retrognatism, voluntary protrusion of the mandible was absent, mentosternal distance of 11 cm and mento-thyroid distance of 6 cm, therefore receiving a score of 5 on the Wilson scale. The patient signed an informed consent after being informed about the procedure. After monitoring and oxygenation, continuous infusion of dexmedetomidine was initiated. Superior and inferior laryngeal nerve block was performed with 2.0% lidocaine without vasoconstrictor and the hypopharinx was anesthetized with a lidocaine spray. Before NTI, ondansetron, midazolam, fentanyl, and droperidol were administered and the patient remained awake and cooperative. Nasal insertion of the tracheal tube was oriented by its opacification and respiratory sounds and the placement was confirmed by pulmonary auscultation and capnography. Continuous infusion of propofol and remifentanil was instituted, vecuronium was administered and controlled ventilation was initiated. The surgery lasted 60 minutes without intercurrences. At the end, the patient was breathing spontaneously, so she was extubated and transferred to the recovery room from where she was discharged without any complaints.

CONCLUSION: Nasotracheal intubation is an alternative to fiberoptic endoscopy when safety and control of the airways is uncertain. Informing the patient about the procedure was essential. Safety was assured and respiratory depression and hemodynamic instability was not observed.

Key Words: ANESTHESIA, general; INTUBATION, nasotracheal, blind.

RESUMEN

JUSTIFICATIVA Y OBJETIVOS: El abordaje a la vía aérea puede utilizar diversos recursos. Mantener el paciente despierto cuyo control seguro de la ventilación/oxigenación no es muy regular y es una opción cuando existe una duda en cuanto a la intubación. La intubación nasotraqueal (INT) a ciegas es una alternativa a la fibroscopía.

RELATO DEL CASO: Paciente del sexo femenino, 75 años, 56 kg, candidata a la hemimandibulectomia, con inmovilidad cervical por artrodesis, abertura bucal de 2,2 cm, retrognatismo moderado, sin profusión voluntaria de la mandíbula, distancia mento-esternal de 11 cm y mento-tiroidiana de 6 cm, recibiendo 5 puntos en la escala Wilson. La paciente previamente orientada consintió con el procedimiento. Después de la monitorización y oxigenación, se inició la infusión continua de dexmedetomidina. Realizado el bloqueo de los nervios laríngeo superior e inferior con lidocaína a 2,0% sin vasoconstrictor e instilación de lidocaína spray en hipofaringe. Previamente a la INT se administraron ondansetrona, midazolam, fentanil y droperidol, permaneciendo la paciente despierta y cooperante. La inserción vía nasal de tubo traqueal fue orientada por su opacificación y ruidos respiratorios y confirmada por auscultación pulmonar y capnografía. Iniciada infusión continua de propofol y remifentanil, administrados rocuronio y ventilación controlada. La operación de 60 minutos no tuvo intercurrencias. Al término de la cirugía, la paciente presentaba ventilación espontánea, siendo extubada y llevada a la recuperación postanestésica, recibiendo alta sin quejas.

CONCLUSIONES: La INT es una alternativa a la fibroscopía cuando la seguridad del control de las vías aéreas no es segura. La previa clarificación de la paciente fue esencial. Hubo seguridad, sin depresión respiratoria o inestabilidad hemodinámica.

INTRODUCTION

Proper airway maintenance is one of the concerns during anesthesia. Therefore, the presence of difficult airway constitutes one of the greatest challenges for the anesthesiologist who should have several resources available in order to guarantee opened airways. The difficult airway algorithm of the American Society of Anesthesiologists (ASA) recommends the use of several devices, such as: laryngeal mask, ML-Fastrack^®, retrograde intubation, lighted guide-wire and fiberoptic endoscopy ¹.

In situations where safe ventilation and oxygenation control without the risk of aspiration of gastric contents are questionable, as well as whenever there are doubts whether intubation will be possible, management of the airways with awaken patient is recommended ².

Blind nasal intubation is an option whenever oral access is difficult or even impossible (as is the case of restricted mouth opening or cervical immobility) ³ and it was the technique chosen for this patient who presented a restriction to oral opening secondary to osteoradionecrosis and osteomyelitis of the mandible and left temporomandibular joint, besides immobility due to cervical fixation with a metal pin.

The objective of this report was to show the importance of blind nasal intubation on awake patient as an alternative to fiberoptic endoscopy, whenever it is not available, and to discuss the use of dexmedetomidine in this technique since it induces sedation without respiratory depression contributing to reduce patient distress, therefore increasing his/her collaboration ⁴.

CASE REPORT

This is a 75-year old female patient, weighing 56 kg, with a history of breast cancer diagnosed and treated 22 years prior to this admission. Three years ago, bone metastasis was detected in the cervical spine, and she underwent cervical fixation with a metal rod in an attempt to eradicate paresthesia in the upper limbs caused by compression of C₄ and C₅ nerve roots. After fixation, chemo and radiotherapy were initiated and the patient evolved over the course of the past three years to radionecrosis and osteomyelitis of the left mandible, being admitted for left hemimandibulectomy.

During pre-anesthetic evaluation, difficult airway was predicted due to the limited head and neck mobility secondary to cervical vertebrae fixation with metal rods, as can be seen in the X-rays (Figure 1); mouth opening of 2.2 cm (Figure 2); mentosternal distance of 11 cm and mento-thyroid distance of 6 cm; moderate retrognatism; and hindered Mallapanti evaluation (Figure 3), receiving 5 points in the Wilson scale.

Since this might be a difficult intubation and fiberoptic endoscopy was not available, it was decided to perform blind intubation with the patient awaken.

The patient was admitted to the operating room one hour after the oral administration of 5.0 mg of diazepam. After the procedure was explained to the patient, she signed an informed consent. Monitoring consisted of cardioscope, pulse oximetry, non-invasive blood pressure and a capnograph and gas analyzer were also available.

After oxygenation with a face mask with 100% oxygen, continuous infusion of dexmedetomidine (induction with 0.5 µg.kg^-1 over 10 minutes and maintenance with 0.5 µg.kg^-1.h^-1) was instituted.

Bilateral superior laryngeal nerve block was done through the superior horn of the thyroid cartilage with 2 mL of 2% lidocaine without vasoconstrictor and transtracheal instillation of 3 mL of the same anesthetic, besides instillation of 10% lidocaine spray on the hypopharynx. Afterwards, 4 mg of ondansetron, 3 mg of midazolam, and 50 µg of fentanyl with 2.5 mg of droperidol were administered and the patient remained awake and cooperative during the procedure.

Nasal introduction of a transparent 5.5 endotracheal tube with cuff was aided by respiratory sounds and opacification of the tube itself and it was confirmed by bilateral lung auscultation and capnography (Figure 4). Continuous infusion of remifentanil (0.1 µg.kg^-1.min^-1) and 2% propofol (target-controlled dose of 1 µg.mL^-1) was initiated, 50 mg of rocuronium were administered and pressure controlled ventilation was instituted (Figure 5).

The surgery lasted 60 minutes without intercurrences. After it was over, the patient was awake and breathing spontaneously, being extubated and transferred to the recovery room, where she remained hemodynamically stable and eupneic. She was discharged to the regular ward one hour later.

The following day, the patient was well and without complaints about the intubation technique. She remained in the hospital for three more days for intravenous antibiotic therapy.

DISCUSSION

Difficult airway is defined as a situation in which a trained anesthesiologist has difficulty to ventilate the patient with a mask or orotracheal tube. Its approach is based on the algorithm first published in 1993 by the American Society of Anesthesiologists Task Force on Management of the Difficult Airway. Death, brain damage, cardiorespiratory arrest, unnecessary tracheostomy and trauma to the airways are the main complications associated with improper management of the airways and it represents the most frequent cause of complications in anesthesiology. In the United States, approximately 33% of malpractice lawsuits against anesthesiologists are related to complications in the control of the airways and 85% of those represent some degree of hypoxic brain damage or death. Therefore, improper handling of the airways is the most frequent cause of lawsuits in anesthesiology ¹.

Being able to recognize that an airway might be potentially difficult is the first step for the adequate management. Pre-anesthetic evaluation of the patient is aimed at decreasing morbidity and mortality related with airways management. The anamnesis is the first step in the safe control of the airways, since it can anticipate a large proportion of probable ventilation difficulties and help planning management conducts to overcome them. Thus, patient evaluation is extremely important, obtaining a general impression of difficulties related with laryngoscopy and intubation, supraglottic ventilation techniques and capacity of the awake patient to cooperate ^5,6.

It is up to the anesthesiologist to recognize the potential of difficult airways, develop tactics for its approach and guarantee the safety of patients in situations of failed intubation. It is important to know how to use resources and alternatives that can overcome technical difficulties when handling the airways.

If a difficult intubation after anesthetic induction is envisioned, the airway should be controlled while the patient is still awake. When the safe control of ventilation or oxygenation is not assured, awake intubation has several advantages, including maintenance of spontaneous ventilation, the retro-palatal space is maintained opened and increased size of the pharynx, posterior placement of the larynx, and maintenance of the tone of the esophageal sphincter, which reduces the risk of reflux and aspiration ^7,8. And more importantly, if intubation maneuvers fail, spontaneous ventilation is preserved ³. The best results are obtained by a combination of regional block and sedation, which aims at decreasing patient anxiety and help him/her to better tolerate the topical anesthesia and intubation maneuvers ⁹. In this context, the highly selective action on alpha₂-adrenergic receptor of dexmedetomidine is synergistic with other drugs used commonly as well as has a low incidence of side effects and causes minimal respiratory depression ⁴.

Absolute contraindications to elective awake intubation include allergy to the local anesthetic and refusal or incapacity of the patient to cooperate with the procedure ³. Therefore, once the awake intubation is chosen, the patient should be physically and psychologically prepared for the procedure from the pre-anesthetic evaluation period, increasing, consequently, his/her cooperation by learning the importance and the reason for any uncomfortable procedure.

Fiberoptic endoscopy is a more versatile solution to handle awake or unconscious patients who are difficult, or seem difficult, to intubate ¹⁰, as is the case of disorders of unstable or fixed cervical spine, mass effect, or obstruction of the lower or upper airways ¹¹. This is a more effective and less traumatic technique for tracheal intubation in patients who would, otherwise, undergo tracheostomy due to failure of conventional techniques ¹². However, it demands the availability of a specific device and proper operator training. Contraindications to its use are related to the limitations of the device, hypoxia, presence of thick airways secretion, and incapacity of the patient to cooperate ¹³.

Whenever fiberoptic endoscopy is not available, blind basal intubation is an alternative when oral access is difficult or impossible. Auscultation of breath sounds through the endotracheal tube is an important indicator of the location of the tip of the tube and, therefore, this technique is contraindicated in patients with apnea ¹⁴. The main advantage of this technique is its simplicity, and 60% to 70% are successful in the first attempt. It should be noted that one should not delay the decision to abandon the technique when facing difficulties for its performance since prolonged attempts lead to hypoxemia and edema of the glottis (repetitive trauma) ³.

REFERENCES

Submitted em 18 de dezembro de 2006

Accepted para publicação em 24 de setembro de 2007

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*

Received from Centro de Ensino e Treinamento do Hospital Vera Cruz, Campinas, SP

Publication Dates

• Publication in this collection
  17 Jan 2008
• Date of issue
  Feb 2008

History

• Received
  18 Dec 2006
• Accepted
  24 Sept 2007