Limiting Emergence Phenomena After General Anesthesia With Combined LMA and ETT Airway Management Technique

Study Overview
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Brief Summary
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Emergence from general anesthesia with a laryngeal mask airway compared with an endotracheal tube has been shown to favorable with respect to limiting emergence phenomena such as coughing, straining, restlessness, and sympathetic stimulation leading to hypertension and tachycardia. Many anesthesiologists would prefer the use of an ETT to an LMA in cases in which higher ventilation pressures may be required, in those patients who are perceived to be high risk for reflux and pulmonary aspiration of gastric contents, as well as during cases that allow the anesthesiologist to have little accessibility the airway. The aim of this study is to investigate an airway management technique that would allow for the benefits of the ETT in terms of a secure airway for the duration of the surgical procedure as well the potential for less emergence phenomena seen when emerging with an LMA.

Detailed Description
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Emergence from general anesthesia is a critical period of anesthetic management (1. Popat, 2012). The noxious stimuli of an endotracheal tube as well as the excitement stage of anesthesia, commonly seen prior to return of consciousness while emerging from general anesthesia, both lead to emergence phenomena of coughing, straining, and restlessness in addition to physiologic derangements (2. Atkinson, 1987). Physiologically, emergence from anesthesia is associated with rising sympathetic tone (as evidenced by elevated catecholamine levels and the resultant hemodynamic changes of increasing heart rate and blood pressure), intracranial pressure, and intraocular pressure. Airway tone and reflexes are also problematic as they may be depressed by the lingering pharmacologic effects of anesthetics and analgesics leading to decreased airway obstruction or aspiration events. Airway reflexes may also be exaggerated while traversing the excitement stage; this can lead to undesirable consequences of coughing, breath-holding, bucking or in extreme cases laryngospasm. A smooth emergence is preferable for all patients but is required for those patients who would not tolerate the above physiologic changes (e.g. severe aortic stenosis or coronary artery disease, both of which would poorly tolerate tachycardia) or those would be at risk in terms of the procedure that was performed (cerebral aneurysm clipping, carotid endarterectomy, thyroidectomy: procedures in which stress fresh surgical wounds with hypertension and straining would be undesirable). Several airway management (3. Koga 1998, 4. Perello-Cerda 2015) and pharmacologic strategies (5. Minogue 20014, 6. Nho 2009, 7. Guler 2005) have been employed to provide a smooth emergence from general anesthesia. One of the most efficacious strategies is the use of supraglottic airway devices rather than endotracheal tubes. Despite evidence supporting the safety and efficacy of ventilation of SGAs during laparoscopic procedures (8. Natalini 2003, 9. Belena 2012, 10. Carron 2012, 11. Bernardini 2009), many anesthesiologists would prefer the use of an ETT to an SGA in cases in which higher ventilation pressures may be required (obesity, steep Trendeleberg position, pneumoperitoneum). In addition to the cases requiring high ventilation pressures, ETTs are preferred to SGAs in those patients who are perceived to be high risk for reflux and pulmonary aspiration of gastric contents (non-fasted, intestinal obstruction, gastroparesis, parturients), as well as during cases that allow the anesthesiologist to have little accessibility the airway (neurosurgical, ENT, etc). The Bailey maneuver (managing the airway with an ETT throughout the case and then exchanging for an LMA while deeply anesthetized (12. Nair 1995), has also been shown to provide less stimulating emergence. Unfortunately, the Bailey maneuver is relatively contraindicated in cases in which there is the perception that reintubation would be difficult, as the risks of exchanging a functioning airway device for one that has not been tested outweighs the potential benefits of a smooth emergence. The airway management technique under investigation involves initially placing an LMA after induction of anesthesia. Once adequate ventilation has been accomplished using the LMA, the patient will be endotracheally intubated using a fiberoptic bronchoscope and the in situ LMA as a conduit (13. Timmermann 2011). General anesthesia will be maintained with sevoflurane and narcotics at the discretion of the primary anesthesiologist. The patient will be ventilated via the endotracheal tube during the duration of the surgical procedure and then the trachea will be extubated while the patient is at a deep plane of anesthesia after release of the pneumoperitoneum and return to supine positioning. This technique is a potential method for reducing the stress of emergence in patients who would benefit from the use of an endotracheal tube intraoperatively.

Official Title
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Limiting Emergence Phenomena After General Anesthesia for Laparoscopic Surgery With Combined Laryngeal Mask Airway and Endotracheal Tube Airway Management Technique

Conditions
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Limit Emergence Phenomena After General Anesthesia

Intervention / Treatment
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* Procedure: Induction of anesthesia
* Device: Placement of LMA [Ambu (R) AuraGain (TM) disposable laryngeal mask]
* Device: Laryngoscopy and placement of ETT
* Procedure: Ventilation via the ETT
* Procedure: Removal of the ETT
* Procedure: Intubation of the trachea through the LMA
* Procedure: Ventilation via the LMA
* Procedure: Emergence from anesthesia


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: ASA 1-3 Patients undergoing elective laparoscopic surgery Exclusion Criteria: Individuals who cannot provide consent Individuals who would require translation services to provide consent Prisoners Parturients Non-fasted patients (as per HMC Anesthesiology Department NPO policy) Patients felt to be high risk for gastric reflux and pulmonary aspiration (those with gastroparesis, symptomatic GERD, etc.: at the discretion of primary anesthesia team) Those patients with anticipated difficult airway requiring maintenance of spontaneous ventilation (awake intubation)

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Diagnostic
Allocation: Randomized
Intervention Model: Single Group Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: ETT only<br>Endotracheal tube intubation after induction of anesthesia. Ventilation with ETT until emergence. | Procedure: Induction of anesthesia<br>* At the discretion of the primary anesthesiologist. Typically involves the administration of an analgesic agent, hypnotic agent, and neuromuscular blocking agent<br>Device: Laryngoscopy and placement of ETT<br>* Via direct or indirect laryngoscopy. Sizing at the discretion of the primary anesthesiologist. Mallinckrodt (TM) Intermediate Hi-Lo cuffed endotracheal tube (Covidien)<br>Procedure: Ventilation via the ETT<br>* Ventilator mode, tidal volume/ ventilation pressure, respiratory rate, positive end expiratory pressure, inspired to expired ratio at the discretion of the primary anesthesiologist.<br>Procedure: Removal of the ETT<br>* Either upon emergence of anesthesia after suctioning of the oropharynx and after a positive pressure breath or while deeply anesthetized after release of the pneumoperitoneum in the combined LMA/ETT group.<br>Procedure: Emergence from anesthesia<br>* At the discretion of primary team. Airway device (either ETT or LMA) will be removed when patient is adequately ventilating and able to respond to commands (such as open your eyes or squeeze my hand).<br>|
| Experimental: Combined ETT/LMA technique<br>Placement of LMA after induction of anesthesia. Intubation of trachea with ETT via LMA with fiberoptic bronchoscope. Ventilation with ETT throughout case. Removal of ETT while deeply anesthetized. Ventilation with LMA until emergence. | Procedure: Induction of anesthesia<br>* At the discretion of the primary anesthesiologist. Typically involves the administration of an analgesic agent, hypnotic agent, and neuromuscular blocking agent<br>Device: Placement of LMA [Ambu (R) AuraGain (TM) disposable laryngeal mask]<br>* By standard method. Sizing at the discretion of the primary anesthesiologist.<br>Procedure: Ventilation via the ETT<br>* Ventilator mode, tidal volume/ ventilation pressure, respiratory rate, positive end expiratory pressure, inspired to expired ratio at the discretion of the primary anesthesiologist.<br>Procedure: Removal of the ETT<br>* Either upon emergence of anesthesia after suctioning of the oropharynx and after a positive pressure breath or while deeply anesthetized after release of the pneumoperitoneum in the combined LMA/ETT group.<br>Procedure: Intubation of the trachea through the LMA<br>* With ETT using fiberoptic bronchoscope guidance.<br>Procedure: Ventilation via the LMA<br>* After removal of the ETT. Ventilator mode, tidal volume/ ventilation pressure, respiratory rate, positive end expiratory pressure, inspired to expired ratio at the discretion of the primary anesthesiologist.<br>Procedure: Emergence from anesthesia<br>* At the discretion of primary team. Airway device (either ETT or LMA) will be removed when patient is adequately ventilating and able to respond to commands (such as open your eyes or squeeze my hand).<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in rate pressure product during emergence | Difference in heart rate multiplied by systolic blood pressure measured during the  5 minutes prior to emergence and the  5 minutes after removal of the airway device. Heart rate is continuously monitored and recorded at one minute intervals. Blood pressure is intermittently monitored at 3 minute intervals. The two SBPs measured prior to removal of the airway device will be multiplied by the HR at those times and the RPPs will be averaged. This will be compared with average of the product of the two SBPs and their corresponding HRs measured after removal of the airway device. | Intraoperative | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Time to successful ventilation via ETT | From administration of induction medication until ETT placement confirmed via capnography. | Intraoperative | 
| Change in rate pressure product during induction of anesthesia and intubation | Difference in heart rate multiplied by systolic blood pressure measured during the  5 minutes prior to induction of anesthesia and the  5 minutes after placement of the airway device. Heart rate is continuously monitored and recorded at one minute intervals. Blood pressure is intermittently monitored at 3 minute intervals. The two SBPs measured prior to placement of the airway device will be multiplied by the HR at those times and the RPPs will be averaged. This will be compared with average of the product of the two SBPs and their corresponding HRs measured after placement of the airway device. | Intraoperative | 
| Success rate of ventilation with LMA after extubation of trachea | After deflation of the pneumoperitoneum, the ETT will be removed and ventilation will be continued through the LMA. Success will be graded as follows: Adequate ventilation via LMA without need for adjustment. Adequate ventilation via LMA after adjustment of LMA. Inadequate ventilation via LMA. Unable to successfully re-seat LMA and need to re-intubate. | Intraoperative | 
| Presence/ severity of cough during prior to removal of airway device | During 5 minutes prior to removal of airway device. Cough will be graded as follows: None Mild = 1 episode of unsustained coughing (< 5 s) Moderate = More than 1 episode of unsustained (<5 s) coughing Severe = Sustained bout(s) of coughing (>5 s) http://www.ncbi.nlm.nih.gov/pubmed/15385385 - (5. Minogue 2004) | Intraoperative | 
| Presence/ severity of cough during after removal of airway device | During 5 minutes after removal of airway device. Cough will be graded as follows: None Mild = 1 episode of unsustained coughing (< 5 s) Moderate = More than 1 episode of unsustained (<5 s) coughing Severe = Sustained bout(s) of coughing (>5 s) http://www.ncbi.nlm.nih.gov/pubmed/15385385 - (5. Minogue 2004) | Intraoperative | 
| Total opioids (morphine equivalents) administered intraoperatively | From pre-induction until patient hand-off to post-anesthesia care unit team. Total intraoperative narcotics will be converted to morphine equivalents. | Intraoperative | 
| LMA cuff pressures when inflated to seal | After placement of LMA and LMA cuff inflated to seal. Pressure in the cuff will be measured and then deflated to pressures of 50-60 cmH20. | Intraoperative | 
| LMA cuff pressures prior to removal of ETT. | After deflation of the pneumoperitoneum. Pressure in the cuff will be measured and then deflated to pressures of 50-60 cmH20. | Intraoperative | 
| Presence of oropharyngeal sensory or motor nerve palsy. | Postoperative day 3-5. A phone call will be made to determine the number of participants with the presence of any oropharyngeal numbness / paresthesias, hoarseness (recurrent laryngeal n. - Lehnert, 2008), dysphagia/ dysarthria (hypoglossal n. - Takahoko, 2014 & Shah, 2015), decreased sensation and sense of taste (lingual n. - El Toukhy, 2012) that could be indicative of a neuropraxia versus nerve palsy. | Up to 1 week | 
| Presence of sore throat. | Postoperative day 3-5. A phone call will be made to determine the number of participants with sore throat (subjectively rated as none, mild, or severe). | Up to 1 week |