Use of remifentanil for awake fiberoptic intubation in a morbidly obese patient with severe inflammation of the neck

Evolution of the treatment of severe odontogenic infections over 50 years: A comprehensive review

Objectives

Severe odontogenic infections remain a challenge for maxillofacial surgeons. The aim of this work is to review the literature to provide an update of knowledge on the topic.

Methods

A comprehensive review of articles in PubMed, Web of Science and Africa Journals Online was performed through searching for "severe odontogenic infections." No language restrictions were applied. Only articles pertaining to treatment options were retrieved. Articles from the past 50 years were included.

Results

A total of 84 articles from 39 countries worldwide were included. Severe odontogenic infections are not unique to low- and middle-income countries but also pose challenges in developed countries. Surgical management and antibiotic therapy for this type of infection is discussed. Some immunocompromised patients have high risks of complications and mortality rates. A world map of publications on the topic is provided.

Conclusions

Several important aspects of managing severe odontogenic infections are discussed. Predictors of severity in addition to recommended antibiotic choice have been debated. Diabetes mellitus is a poor predictor of the prognosis of odontogenic infections.

Dexmedetomidine in the Management of Awake Fiberoptic Intubation

Awake Fibreoptic Intubation (AFOI) is, nowadays, the gold standard in predicted difficult airway management. Numerous practice guidelines have been developed to assist clinicians facing with a difficult airway. If conducted without sedation, it is common that this procedure may lead to high patient discomfort and severe hemodynamic responses. Sedation is frequently used to make the process more tolerable to patients even if it is not always easy to strike a balance between patient comfort, safety, co-operation, and good intubating conditions. In the last years, many drugs and drug combinations have been described. This minireview aims to discuss the evidence supporting the use of Dexmedetomidine (DEX) in the AFOI management.

[General anesthesia and intensive care for patients surgically treated for deep neck odontogenic infections]

The study objectives were to determine the significance of deep neck odontogenic infections severity to predict the postoperative morbidity. Observational study was conducted in 2014-2015. A continuous sample of 38 patients who were urgently hospitalized in the Novosibirsk Regional Clinical Hospital with deep neck odontogenic infections and operated on the day of hospitalization was analyzed. SAPS scale rates correlated positively with the duration of the artificial lungs ventilation (ALV). The positive balance of the introduced and withdrawn liquid in the first day of the postoperative period is associated with the ALV duration, which requires accurate dosing of the infusion volumes. The described protocol of perioperative care significantly decreases morbidity in patients with deep neck odontogenic infections.

Successful intubation of a difficult airway due to a large obstructive vocal cord polyp augmented by the delivery of a transtracheal injection of local anaesthetic

We describe a case of a very difficult intubation which was safely navigated through careful planning. Our patient presented initially with increasing hoarseness and shortness of breath over a 6-month period. This was investigated and the patient was found to have a large vocal cord mass and was referred for urgent microlaryngoscopy and vocal cord polypectomy. On the day of surgery the obstruction was noted and awake fiberoptic bronchoscopy was used with a remifentanil infusion. Given the mass was large and increased in size with expiration, the time frame to pass the tube was extremely short. We delivered a transtracheal injection of local anaesthesia. This approach allowed for safe passage of the endotracheal tube. In patients such as this it may be worth considering the use of a transtracheal injection in the first instance.

Conscious sedation for awake fibreoptic intubation: a review of the literature

PURPOSE

Awake fibreoptic intubation (AFOI) is the gold standard of management of the predicted difficult airway. Sedation is frequently used to make the process more tolerable to patients. It is not always easy to strike a balance between patient comfort and good intubating conditions on the one hand and maintaining ventilation and a patent airway on the other. In the last 30 years, many drugs and drug combinations have been described, but there is very little in the literature to help guide the practitioner to choose between them. The objective of this article is to discuss the evidence supporting the use of the agents described with regard to their efficacy, recommended doses and techniques, and limitations to their use for AFOI.

SOURCE

Publication databases were searched for articles published from 1996 to 2012 relating to sedation for AFOI.

PRINCIPLE FINDINGS

Benzodiazepines, propofol, opioids, alpha2-adrenoceptor agonists, and ketamine are the main classes of drugs that have been described to facilitate AFOI. Drugs that are most suitable have a combination of both anxiolytic and analgesic properties. The ideal choice of drug may vary depending on the patient and the indication for AFOI.

CONCLUSION

There is good evidence to support the use of two drugs in particular, remifentanil and dexmedetomidine. Each has certain unique characteristics that make them an attractive choice for an AFOI.

[Fibreoptic clinical training in anaesthesia. Course design and results based on a self-assessment survey]

BACKGROUND AND OBJECTIVE

Fibreoptic intubation is the technique of choice for resolving complications related to a difficult airway. Our aim was to determine whether a clinical-practice-based, individualized course provides sufficient training and confidence to allow anaesthetists to routinely practice fibreoptic intubation.

METHODS

Our hospital developed a clinical-practice-based, individualized course on fibreoptic intubation in general anaesthesia that provided practice in sedated spontaneously breathing patients and insertion through supraglottic devices. From 2005 to 2009, we e-mailed participants for response to an anonymous online self-assessment survey. We asked participants about the training outcomes and their overall degree of satisfaction.

RESULTS

Seventy-seven participants were sent the questionnaire six months after the course and 61% responded. All respondents considered themselves skilled in handling the bronchoscope at the end of the course and 97% used it in their routine practice in patients with difficult airways.

CONCLUSIONS

These results suggest a high success rate can be expected from individually tailored fibreoptic intubation courses that supplement theory and mannequin experience with clinical practice.

Dexmedetomidine versus remifentanil sedation during awake fiberoptic nasotracheal intubation: a double-blinded randomized controlled trial

BACKGROUND

Awake fiberoptic nasotracheal intubation is usually performed in patients with an anticipated difficult airway. This study compares dexmedetomidine and remifentanil for conscious sedation during fiberoptic intubation.

METHODS

Forty patients undergoing elective awake fiberoptic nasotracheal intubation were allocated randomly to receive either dexmedetomidine (n = 20) or remifentanil (n = 20). Primary outcome measures were endoscopy, intubation, and post-intubation conditions as scored by the attending anesthesiologist. Other parameters included the time taken to achieve the desired level of sedation, endoscopy time, intubation time, and hemodynamic changes during the procedure. An interview was conducted 24 h after surgery to evaluate patients' recall of and satisfaction with the procedure.

RESULTS

The median [interquartile range] endoscopy score (graded 0-5) in the dexmedetomidine group (2 [1-2]) was significantly better than in patients who received remifentanil (3 [2-3]; p < 0.01). Recall of intubation was significantly lower in the dexmedetomidine group (p = 0.027). Dexmedetomidine provided better patient satisfaction than remifentanil (2 [1-2] and 2 [2-3], respectively; p = 0.022). Patients in the dexmedetomidine group had fewer heart rate responses during endoscopy and intubation as compared to the remifentanil group (p < 0.001 and p = 0.004, respectively). Peripheral oxygen saturation was less in the remifentanil group during endoscopy (p = 0.003). There were no significant differences in intubation and post-intubation conditions.

CONCLUSIONS

Both dexmedetomidine and remifentanil were effective as sedatives in patients undergoing awake fiberoptic nasotracheal intubation. Compared with remifentanil, dexmedetomidine offered better endoscopy scores, lower recall of intubation, and greater patient satisfaction, with minor hemodynamic side effects.

Laryngoscopy in conscious patients with remifentanil: how useful is an "awake look"?

STUDY OBJECTIVE

To determine the sensitivity and specificity of direct laryngoscopy in the conscious patient as a diagnostic test for difficult direct laryngoscopy in the unconscious patient.

DESIGN

Prospective case series.

SETTING

Various operating rooms in a Canadian tertiary-care hospital.

PATIENTS

81 ASA physical status 1, 2, and 3 subjects undergoing elective surgery.

INTERVENTIONS

A bolus of midazolam was given and a continuous infusion of remifentanil was started and adjusted as needed. Direct laryngoscopy was performed in the conscious subject. No topical anesthesia was applied to the upper airway.

MEASUREMENTS

The modified Cormack-Lehane grade was recorded with each subject conscious and unconscious. Other data collected before the intervention included age, gender, height, weight, body mass index, Mallampati class, thyromental distance, mouth opening, previous history of failed or difficult intubation, history of hypertension or obstructive sleep apnea, and routine use of beta blockers. The time of intravenous placement, total dose and duration of remifentanil infusion, and time of endotracheal tube placement were recorded. The lowest oxygen saturation, lowest and highest systolic blood pressure and heart rate, and presence or absence of gagging, coughing, or chest wall rigidity were also noted. Subjects were also asked to complete a questionnaire in the recovery room regarding recall and the degree of discomfort experienced.

MAIN RESULTS

43 of 81 subjects were graded 1 or 2a when the laryngoscopy was done in the conscious subject. Six of the 38 subjects who were graded as a difficult laryngoscopy (grade 2b or higher) when they were conscious also remained a difficult laryngoscopy when unconscious and paralyzed. Sensitivity and specificity of direct laryngoscopy in the conscious subject as a diagnostic test for difficult direct laryngoscopy in the unconscious subject were 100% [95% confidence interval (CI) 0.52 to 1] and 57% (95% CI 0.47 to 0.70), respectively.

CONCLUSIONS

Using remifentanil as the sole analgesic allows evaluation of the larynx with direct laryngoscopy in a conscious patient. A poor Cormack-Lehane grade in a conscious patient may or may not improve with general anesthesia.

Pathologic paediatric conditions associated with a compromised airway

PURPOSE

The purpose was to describe pathologic paediatric conditions associated with airway compromise adversely affecting dental treatment with sedation and general anaesthesia.

METHODS

A review of available literature was completed, identifying pathologic paediatric conditions predisposing to airway compromise.

RESULTS

Airway-related deaths are uncommon, but respiratory complication represents the greatest cause of morbidity and mortality during the administration of general anaesthesia. Differences in anatomy and physiology of the paediatric and adult airway contribute to the child's predisposition to rapid development of airway compromise and respiratory failure; juvenile rheumatoid arthritis, cervical spine injury, morbid obesity, and prematurity represent only a few conditions contributing to potential airway compromise of which the paediatric clinician needs to be aware. In all cases, thorough physical examination prior to treatment is mandated to affect a positive treatment outcome.

CONCLUSIONS

Successful management of children and adolescents with a compromised airway begins with identification of the problem through a detailed medical history and physical examination. Due to the likely fragile nature of many of these patients, and possibility of concomitant medical conditions affecting airway management, dental treatment needs necessitating pharmacological management are best treated in a controlled setting such as the operating room, where a patent airway can be maintained.

[Transorbital fiberoptic intubation: a predictable difficult intubation in cephalic surgery]

Management of the difficult adult airway is a crucial problem in anaesthesia. It is the first cause of anaesthetic mortality and morbidity. We report here the case of a patient who could only be intubated through the orbital cavity. We discuss our technique of intubation compared to the other rare procedures described in the literature. We also focus on our anaesthetic protocol and the interest of preserving spontaneous ventilation for intubation. Use of short acting anaesthetic drugs can help to achieve such conditions.

Remifentanil update: clinical science and utility

The anilidopiperidine opioid remifentanil has pharmacodynamic properties similar to all opioids; however, its pharmacokinetic characteristics are unique. Favourable pharmacokinetic properties, minimally altered by extremes of age or renal or hepatic dysfunction, enable easy titration and rapid dissipation of clinical effect of this agent, even after prolonged infusion. Remifentanil is metabolised by esterases that are widespread throughout the plasma, red blood cells, and interstitial tissues, whereas other anilidopiperidine opioids (e.g. fentanyl, alfentanil and sufentanil) depend upon hepatic biotransformation and renal excretion for elimination. Consequently, remifentanil is cleared considerably more rapidly than other anilidopiperidine opioids. In addition, its pKa (the pH at which the drug is 50% ionised) is less than physiological pH; thus, remifentanil circulates primarily in the non-ionised moiety, which quickly penetrates the lipid blood-brain barrier and rapidly equilibrates across the plasma/effect site interface. By virtue of these distinctive pharmacokinetic properties, the context-sensitive half-time (i.e. the time required for the drug's plasma concentration to decrease by 50% after cessation of an infusion) of remifentanil remains consistently short (3.2 minutes), even following an infusion of long duration (> or =8 hours). Remifentanil, a clinically versatile opioid, is useful for intravenous analgesia and sedation in spontaneously breathing patients undergoing painful procedures. Profound analgesia may be achieved with minimal effect on cognitive function. Remifentanil may also provide sedation and analgesia during placement of regional anaesthetic blocks, and in conjunction with topical anaesthesia and airway nerve blocks, it may be useful for blunting reflex responses and facilitating 'awake' fibreoptic intubation. Compared with fentanyl and alfentanil in a day-surgery setting, remifentanil supplementation of general anaesthesia may improve intraoperative haemodynamic control. Both emergence time and the incidence of respiratory depression during post-anaesthetic recovery may be reduced. However, outcomes such as home discharge time, post-emergence adverse effect profile, and patient and provider satisfaction are not significantly improved, and the incidence of intraoperative hypotension and bradycardia is greater. In addition, drug acquisition costs for remifentanil are higher and clinicians may need extra time to familiarise themselves with the drug's unique pharmacokinetics.Ironically, the quick dissipation of opioid analgesic effect following remifentanil discontinuation may be a significant clinical disadvantage. Unless little or no postoperative pain is anticipated, the clinician may wish to treat prospectively using local or regional anaesthesia, non-opioid analgesics, or longer-acting opioid analgesics.

Awake nasotracheal fiberoptic intubation: patient comfort, intubating conditions, and hemodynamic stability during conscious sedation with remifentanil

Awake nasotracheal fiberoptic intubation requires an anesthetic management that provides sufficient patient comfort, adequate intubating conditions, and stable hemodynamics. Short-acting and easily titratable analgesics are excellent choices for this maneuver. In this study, our aim was to determine an appropriate dosage regimen of remifentanil for awake nasotracheal fiberoptic intubation. For that reason, we compared two different dosage regimens. Twenty-four patients were randomly assigned to receive remifentanil 0.75 micro g/kg in bolus, followed by a continuous infusion of 0.075 micro g x kg(-1) x min(-1) (Group L), or remifentanil 1.5 micro g/kg in bolus, followed by a continuous infusion of 0.15 micro g x kg(-1) x min(-1) (Group H). All patients were premedicated with midazolam 0.05 mg/kg IV and glycopyrrolate 0.2 mg IV. Both dosage regimens ensured patient comfort and sedation. Discomfort did not differ between groups. Patients in Group H were sedated more profoundly. Hemodynamic stability was maintained with both remifentanil doses. Intubating conditions were adequate in all patients and comparable between the groups. The large dosage regimen did not result in any additional benefit compared with the small dosage. For awake nasotracheal fiberoptic intubation, we therefore recommend remifentanil 0.75 micro g/kg in bolus followed by continuous infusion of 0.075 micro g x kg(-1) x min(-1), supplemented with midazolam 0.05 mg/kg.

Remifentanil: an update

PURPOSE OF REVIEW

Remifentanil has now reached maturity, as reflected by the increasing number of clinical papers relating to its use. Its position among anaesthetic drugs is now better understood, and this review will attempt to place it in the context of current clinical practice.

RECENT FINDINGS AND SUMMARY

Propofol reduces the initial distribution of remifentanil, leading to higher concentrations during induction. Propofol and remifentanil administered together at sedative doses display a major synergistic interaction on the respiratory drive. Remifentanil accelerates the penetration of sevoflurane to its site of effect. The risk of intraoperative awareness seems to be low when remifentanil is associated to very low concentrations of hypnotic drugs, but this field warrants further investigation. Acute tolerance to opioids and its prevention remain controversial.

SUMMARY

Remifentanil is the opioid of choice for tracheal intubation without muscle relaxants. It provides an alternative to regional anaesthesia in labour pain control. Target-controlled infusion may further improve the administration of remifentanil.