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| ORIGINAL ARTICLE |
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| Year : 2020 | Volume
: 21
| Issue : 2 | Page : 114-120 |
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A comparative study of desflurane/fentanyl with sevoflurane/fentanyl on time of awakening and airway morbidity in ambulatory surgery using a supraglottic airway device: A randomized, single-blind study
Sansaya Mahapatra1, Raj Tobin2, Alok Gupta2, Nitin Choudhary3, Soumya Dash4
1 Department of Anaesthesiology and Critical Care, Maulana Azad Medical College, New Delhi, India
2 Department of Anesthesia and Pain Management, Max Superspeciality Hospital, New Delhi, India
3 Department of Anaesthesiology, ABVIMS and Dr. RML Hospital, New Delhi, India
4 Department of Gynaecology and Obstetrics, Hindurao Hospital, New Delhi, India
| Date of Submission | 05-Mar-2020 |
| Date of Decision | 09-Apr-2020 |
| Date of Acceptance | 19-Apr-2020 |
| Date of Web Publication | 19-Sep-2020 |
Correspondence Address:
Dr. Nitin Choudhary
Flat No-1601, Gardenia Gitanjali Apartment, Vasundhara Sector-18, Ghaziabad - 201 012, Uttar Pradesh
India
 Source of Support: None, Conflict of Interest: None  | Check |
DOI: 10.4103/TheIAForum.TheIAForum_22_20
Background and Aims: The goal of anesthesia for ambulatory surgeries is rapid recovery with decreased hospital stay for rapid turnover of patients. We aim to compare desflurane and sevoflurane with regard to their recovery profile and incidence of airway morbidity and to study the effect of opioid (fentanyl) on these study parameters.
Methods: We randomized seventy American Society of Anesthesiologists physical status I and II patients, aged 18–60 years of either sex undergoing elective surgery of less than an hour duration into two groups: Group D (desflurane + fentanyl) and Group S (sevoflurane + fentanyl). After standard induction of anesthesia, Proseal™ laryngeal mask airway was inserted. Intravenous fentanyl was administered based on entropy values. Anesthesia was maintained on a group-specific inhalational agent. We recorded the time taken for eye opening, follow commands, vocalize, attain modified Aldrete score ≥9 in postanesthesia care unit (PACU), incidence of airway morbidity, rescue analgesic requirement in 1st h postoperatively, and any other complication.
Results: The mean time to awakening was significantly faster in Group D (P < 0.001) with shorter stay in PACU (P < 0.001). Incidence of airway morbidity was higher in Group D than Group S, but was not statistically significant (P = 0.710).
Conclusion: Desflurane provides faster recovery with shorter PACU stay compared to sevoflurane with comparable incidence of airway morbidity. Opioids may affect airway morbidity, but must be used judiciously to avoid its unwanted effect on recovery.
Keywords: Ambulatory anesthesia, desflurane, opioid, sevoflurane
How to cite this article:
Mahapatra S, Tobin R, Gupta A, Choudhary N, Dash S. A comparative study of desflurane/fentanyl with sevoflurane/fentanyl on time of awakening and airway morbidity in ambulatory surgery using a supraglottic airway device: A randomized, single-blind study. Indian Anaesth Forum 2020;21:114-20 |
How to cite this URL:
Mahapatra S, Tobin R, Gupta A, Choudhary N, Dash S. A comparative study of desflurane/fentanyl with sevoflurane/fentanyl on time of awakening and airway morbidity in ambulatory surgery using a supraglottic airway device: A randomized, single-blind study. Indian Anaesth Forum [serial online] 2020 [cited 2023 Jun 2];21:114-20. Available from: http://www.theiaforum.org/text.asp?2020/21/2/114/295326 |
| Introduction | |  |
Ambulatory surgeries have been possible due to rapid advancements in the field of anesthesia. Fast track anesthesia primarily aims to provide optimal surgical conditions along with rapid recovery and minimal side effects with resultant decrease in the duration of hospital stay.[1] Newer short-acting drugs with advanced monitoring aids to allow careful titration of anesthetic drugs have made this distant dream into present-day reality.[2] For fast tracking of patients in an ambulatory setting, meeting the discharge criteria from postanesthesia care unit (PACU) at the earliest is of utmost importance.
The most important determinant affecting the recovery from anesthesia is the type of anesthesia technique.[3] Desflurane and sevoflurane are the two routinely used inhalational agents for conduct of anesthesia in day care settings owing to their pharmacological properties.[4] Although desflurane provides rapid onset and offset of anesthesia as desired for successful conduct of ambulatory anesthesia, its physical property of being an irritant inhalational agent may result in increased airway morbidity.[5] Therefore, the role of desflurane in spontaneous breathing patients remains questionable for the fear of increased chances of adverse airway events. There are very limited studies to support the use of desflurane in spontaneous respiration with emphasis on associated airway morbidity.[6]
We hypothesized that desflurane has early recovery with comparable airway morbidity in patients with no airway reactivity compared to sevoflurane when used in spontaneously breathing patients in short day care surgeries. Therefore, we planned to conduct a study with the primary objective to compare the time taken to awakening from anesthesia using desflurane and sevoflurane using opioid-based balanced anesthesia technique. The secondary objectives of the study were the time taken to follow verbal commands, vocalize, attain modified Aldrete score ≥9 in PACU, incidence of airway morbidity, rescue analgesic requirement in 1st h postoperatively, and any other complication.
| Methods | | |
This was a prospective, randomized, single-blind, control study which was conducted in a tertiary care hospital over a period of 1 year after obtaining prior approval from the institutional ethics committee. Written informed consent was obtained from all the study participants after explaining them about the objective of our study, the associated technique, and its related complications.
Seventy American Society of Anesthesiologists (ASA) physical status I and II patients between 18 and 60 years of age of either sex having body mass index ≤30 kg/m2 with modified Mallampati Grade I and II and interincisor gap >3 cm planned for ambulatory surgery under general anesthesia lasting <60 min were included in the study.
Patients with anticipated difficult airway, history of snoring, pregnancy, active upper respiratory tract infection, acute or chronic lung disease, increased risk of aspiration, on antidepressants, psychiatric disorders, chronic opioid or corticosteroid use, liver or renal disease, history of gastritis, and patient's refusal for participation were excluded from the study.
All patients were randomly allocated into two groups, namely, Group D (desflurane/fentanyl) and Group S (sevoflurane/fentanyl). Randomization was done by a computer-generated allocation schedule using allocation concealment to prevent prior knowledge of treatment assignment. Numbers were assigned in strict chronological sequence and study participants were entered in sequence. Each study participant was allocated a unique randomization number on successful completion of screening. To decrease bias and confounders, the decision to accept or reject a participant was made using inclusion and exclusion criteria. Informed consent was obtained from participants before obtaining the randomization code.
All patients underwent a detailed preoperative evaluation with history, general and systemic examination, and airway assessment. Patients fulfilling the inclusion criteria were kept nil per oral as per the standard ASA guidelines. All patients were premedicated with alprazolam 0.25 mg and pantoprazole 40 mg at 6 am on the day of surgery with sips of water. In the operating room, clinical monitoring included electrocardiography, pulse oximetry, noninvasive arterial blood pressure, capnography, and entropy sensor (GE Healthcare). All patients were placed in supine position and baseline vital parameters and entropy values were recorded. A 20-gauze intravenous cannula was secured over nondominant hand and ringer lactate/normal saline solution was started. All patients were premedicated with midazolam 0.02 mg/kg intravenously. General anesthesia was induced with titrated doses of propofol intravenously till the loss of verbal response was attained. After assessing the adequacy of jaw relaxation, a prelubricated (using water based jelly) Proseal™ laryngeal mask airway (PLMA™) of appropriate size was inserted with the help of introducer. The size selection of PLMA™ was based on the patient's body weight as recommended by the manufacturer. Correct placement of PLMA™ was ensured with adequate chest rise, appearance of square-shaped capnograph, and adequate seal. The Ryle's tube was inserted via gastric channel. Only two attempts were allowed for correct PLMA™ placement. If PLMA™ was not placed correctly even after the 2nd attempt, the patient was excluded from further statistical analysis and was managed as per the standard protocol (either a different supraglottic device was selected or the operator was changed based on the decision of the senior anesthetist in the operation theater). The cuff pressure was measured and monitored continuously to maintain it below 60 cmH2O during the entire duration of surgery. The patient was maintained on spontaneous respiration targeting a respiratory rate of 12–16 breaths/min, and if required, intermittent positive pressure ventilation was given to maintain the end-tidal carbon dioxide in the range of 30–40 mmHg. Adequate depth of anesthesia was maintained by a group-specific inhalational agent at 1.0 minimum alveolar concentration (MAC) using an end-tidal concentration measurement. Entropy was measured at all times maintaining the values between 40 and 60. Response and state entropy values were continuously monitored, and based on their values, opioid was administered intravenously throughout the duration of surgery. If the difference between response and state entropy was more than 10, fentanyl 25 mcg was administered intravenously and was repeated in similar aliquots to achieve the desired values. The fresh-gas flow (mixture of oxygen and air maintaining inspired concentration of oxygen at 0.50) was initially kept at 8 L/min during induction of anesthesia, until volatile anesthetic concentration reached 1.0 MAC; then, it was reduced to 1 L/min during maintenance of anesthesia. Closed circuit was used during the entire period of anesthesia for the surgery. All patients received 1 g of intravenous paracetamol and 75 mg of intravenous diclofenac immediately after induction of anesthesia. All patients received ondansetron 4 mg intravenously, 30 min before the anticipated completion of surgery. At the end of the procedure, volatile anesthetic agent was discontinued and fresh-gas flow was increased to 8 L/min with 100% oxygen. The procedure of PLMA™ insertion was performed by a single operator who was routinely using PLMA™ for conduct of anesthesia in patients. After the discontinuation of the inhalational agent on achieving MAC value of 0.3–0.4 or entropy value >60, PLMA™ along with Ryle's tube was removed. When the patient was able to open the eyes, follow verbal commands (tongue protrusion), and vocalize, the patient was then shifted to PACU. The patient was monitored in PACU and was assessed every 10 min by trained staff nurse based on the modified Aldrete score, and the final decision of discharge from PACU was taken by the anesthetist.[7] Postoperative pain was assessed on numerical rating scale (NRS) of 0–10 where 0 was no pain and 10 was worst possible pain imaginable.[8] If NRS was ≥4, tramadol 1 mg/kg was administered intravenously as rescue analgesic. The patient was also observed for upper airway morbidity in the form of cough or scratchy throat and was graded. The severity of cough or scratchy throat was graded as 0 – no cough or scratchy throat occurring any time since operation; 1 – minimal scratchy throat or cough less than what is noted with a cold occurring any time since operation; 2 – moderate cough as would be noted with a cold occurring at any time since operation; and 3 – severe cough greater than would be noted with a cold occurring at any time since operation.[9] The patient was discharged from the PACU after attaining modified Aldrete score ≥ 9.
The primary outcome of the study was the total time duration of awakening defined as the time in minutes between discontinuation of volatile anesthetic agent to spontaneous eye opening or any movement of extremities whichever was earlier. The secondary outcomes compared were (1) presence of upper airway morbidity defined as any presence of cough or scratchy throat after discontinuation of volatile anesthetic till 1 h postoperatively; (2) total duration of time to follow commands defined as the time in minutes between discontinuation of volatile anesthetic agent and response to a verbal command; (3) total duration of time to develop coherent speech defined as time to speak name and address after discontinuation of volatile anesthetic agent; (4) time to achieve modified Aldrete score ≥9 was defined the time from admission in PACU till the patient attained modified Aldrete score ≥9; (5) requirement of rescue analgesia in the first postoperative hour; and (6) complications if any.
Based on the study by De Oliveira et al.[10] with time of awakening with desflurane as 6.8 ± 3.5 min and with sevoflurane as 11.8 ± 4.2 min and considering the time of awakening as the primary outcome of our study, the sample size analysis determined that 25 patients per group were required to achieve 90% power at α = 0.05. Assuming the dropout rate of 20%, the sample size required was 60 patients. We took the sample size of convenience as 70 patients.
Statistical analysis used
The data obtained were analyzed using Statistical Package for the Social Sciences (17.0 evaluation version, SPSS inc, Chicago, IL, USA). The continuous data were presented as mean ± standard deviation, and the categorical variables were presented by means of numbers and percentages. The normally distributed continuous variables were compared using Student's t-test. The nominal categorical data were compared using Chi-squared test or Fisher's exact test. P < 0.05 was considered statistically significant.
| Results | | |
The flow of the patients enrolled in the study is represented in the CONSORT flow diagram [Figure 1]. The two groups were comparable with respect to demographic profile [Table 1]. | Figure 1: CONSORT diagram showing the division of patients at every stage of randomized control trial
Click here to view |
In all the patients enrolled in this study, PLMA of sizes 3, 4, and 5 was used and the data were comparable in the study groups [Table 1]. The PLMA was placed correctly in 67 patients in the first attempt, whereas two patients in Group D and in one patient in Group S required the second attempt. The mean duration of surgery (P = 0.002) was longer in Group D with higher requirement of fentanyl (P = 0.018) as compared to Group S [Table 1] and [Table 2]. The time to awakening/eye opening (P <0.001) and time to coherent speech (P <0.001) were significantly shorter in Group D as compared to Group S [Table 3]. The time to attain modified Aldrete score ≥9 was significantly faster in Group D (P <0.001). The cough score was comparable between the two groups (P = 0.710) [Table 4]. One patient in Group D and two patients in Group S required rescue analgesic in the first postoperative hour. No significant hemodynamic fluctuations or any complication was observed in any of the study group.
| Discussion | | |
Ambulatory surgery is required to manage the needs of growing health-care system. Fast tracking of patients in day care surgery requires early recovery from anesthesia with patient satisfaction. Ambulatory surgery not only helps in managing the large volume of patients but also makes it more economical by decreasing the length of hospital stay.[11] Desflurane and sevoflurane have lower blood gas coefficient, which makes them the inhalational agent of choice for ambulatory anesthesia by providing rapid induction as well as emergence from anesthesia.[12] Therefore, we planned to conduct a study to compare the recovery profile and airway morbidity of desflurane and sevoflurane in patients with spontaneous respiration by trying to limit the confounding factors as much as possible which may affect the study results.
In our study, the primary outcome was the time of awakening, which was found to be significantly faster with desflurane. The previous studies also found faster recovery with desflurane compared to sevoflurane, though the time durations are different due to different endpoints taken for calculating the time taken for eye opening after discontinuation of the inhalational agent.[10],[13] Unlike previous studies where opioids were not used in their anesthetic technique, we despite using fentanyl got results which are comparable to them.[13],[14] To limit the administration of opioids in our patients to prevent the side effects of opioids from affecting the recovery profile of inhalational agents as well as the discharge of patients from PACU, we administered fentanyl judiciously based on the entropy values to all our patients. In our study, the duration of surgery as well as the fentanyl requirement was found to be significantly more in desflurane unlike previous mentioned studies; however, we still found faster recovery with desflurane compared to sevoflurane.[13],[14] Hence, opioids in low doses or when given judiciously do not affect the recovery profile of desflurane. The likely reason of increased fentanyl requirement in desflurane group could be because of increased duration of surgery seen in desflurane group and second desflurane is known to cause sympathetic stimulation which could have resulted in increased opioid requirement. In our study, we used entropy as well as MAC to ensure adequate depth of anesthesia and monitor the analgesic requirement unlike previous studies which were mostly centered on achieving the MAC value of 1. Majority of the past studies[6],[10],[14] were conducted on gynecological hysteroscopic procedure, which are superficial procedure unlike our study wherein we also included knee arthroscopy which is a relatively more painful procedure and requires adequate depth of anesthesia with varying analgesic requirement. The secondary outcomes, namely the time taken to follow verbal commands and the time to coherent speech following discontinuation of inhalational agent, were significantly shorter with desflurane. Our study results were in concordance to previous study results.[10],[14]
Early recovery is of utmost importance for assessing the successful outcome of ambulatory anesthesia. We used modified Aldrete score for assessing the time taken for discharge from PACU. We found that the time taken for attainment of modified Aldrete score ≥9 was significantly shorter with desflurane compared to sevoflurane. These findings may be attributable to the fact that desflurane has lower blood gas partition coefficient with rapid elimination and minimal metabolites compared to sevoflurane. A previous study found early discharge from PACU with desflurane, but the total time to discharge from PACU with desflurane was more compared to our study results in spite of the fact that they considered modified Aldrete score ≥8 as the discharge criteria from PACU.[6] The probable reason could be that they administered fentanyl at 1 μg/kg, while we gave it in aliquots of 25 μg based on the entropy values. In another study, they did not find statistically significant difference in the time to discharge between the two inhalational agents, but their time to discharge was much longer compared to our study results.[10] The possible reason could be that they administered fentanyl in aliquots of 25 μg every 5 min or whenever the respiratory rate increased to more than 16/min which could have prolonged the time to discharge from PACU.
In our study, one patient in both the study groups required rescue analgesia in the first postoperative period. These patients were operated for mass excision. Adequate postoperative pain management resulted in shorter stay in PACU. There was no incidence of intraoperative awareness in either study group. Use of muscle relaxants has been associated with higher incidence of intraoperative awareness and is advocated to be best avoided in day care surgeries where muscle relaxation is not a prerequisite.[15],[16] We maintained the patients on spontaneous respiration under monitoring by entropy to ensure depth of anesthesia, prevent awareness under anesthesia, and to avoid use of muscle relaxants.
Desflurane is known airway irritant and may increase the incidence of intraoperative and postoperative airway morbidity. Desflurane in higher concentrations (1–1.5 MAC in 100% O2) may act as respiratory irritant and can precipitate adverse airways events. However, desflurane may not act as airway irritant in lower concentrations (1 MAC in 100% O2), i.e., till end-tidal concentration of 5.4%.[17] In our study, only three patients in desflurane group and two patients in sevoflurane group had postoperative cough or scratchy throat which was not found to be statistically significant. Out of these patients, two patients in desflurane group and one patient in sevoflurane group required second attempt for correct placement of PLMA™, which could be a reason for cough or scratchy throat postoperatively. Endotracheal intubation is associated with higher incidence of sore throat compared to supraglottic airway devices.[18] Therefore, to negate the possible confounding factors responsible for postoperative airway morbidity, we planned to use PLMA as the airway device in our study population. The previous study though found similar results but their incidence of adverse airway events was higher compared to our study results.[6] The possible explanation could be that they did not continuously monitor the cuff pressure and also used nitrous oxide intraoperatively which could have further increased the cuff pressure of PLMA™. Furthermore, they do not mention if they prelubricated the device before insertion and there is no detail about the nature of the lubricant if it was used. Another study also found higher incidence of adverse events with desflurane compared to sevoflurane though it was not statistically significant.[10] In this study, also, the cuff pressure was not monitored and laryngeal mask airway was used in place of PLMA™, which has a reported postoperative sore throat incidence ranging between 2.6% and 42%.[19],[20] There have been studies which have stated the role of opioids in decreasing the incidence of adverse airways events with desflurane by obtunding the airway reflexes. However, there is no consensus on the dose of opioid which ranges from 50 μg to 1 μ/kg.[14],[21] Therefore, opioids on the one hand might help in decreasing the adverse upper airway events, but on the other hand, it can affect the early awakening from desflurane. In our study, we administered fentanyl ranging from 25 μg to 75 μg and still found a lower incidence of airway morbidity compared to previous studies. We believe that the choice of airway device with balanced anesthesia and technique can significantly bring down the incidence of adverse airway events with desflurane. No other adverse airway event such as laryngospasm, hiccups, or breath holding was observed in either study group.
The major limitation of our study was the limited number of patients. Furthermore, we could have used I-Gel® as the supraglottic airway device instead of PLMA as studies have found lower incidence of postoperative airway morbidity with I-Gel®.[22] However, I-Gel® is a single use device and hence was not economical.
| Conclusion | | |
Desflurane/fentanyl provides faster recovery from day care anesthesia by shortening the time to awakening and decreased PACU stay than sevoflurane/fentanyl. Airway morbidity of desflurane is comparable to sevoflurane and can be significantly brought down by being vigilant on other confounding factors associated with adverse airway events. Opioids may have a role in decreasing the incidence of adverse airway events with desflurane, but it must be used judiciously. The choice of anesthesia technique, anesthetic agent, and monitoring together are responsible for favorable patient outcome.
Financial support and sponsorship
Nil.
Conflicts of interest
There are no conflict of interest.
| References | | |
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[Figure 1]
[Table 1], [Table 2], [Table 3], [Table 4]
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