Application of Discharge Criteria for Home Readiness Using Bispectral and Supraglottic Airway Devices in Day-care Surgery without Using Muscle Relaxants.

INTRODUCTION: The availability of rapid and short-acting intravenous and volatile anesthetics has facilitated early recovery that is why nowadays ambulatory surgery is becoming more common. If the criteria used to discharge patients from the Postanesthesia Care Unit (PACU) are met in the operating room (OR), it would be appropriate to consider bypassing the PACU and transferring the patient directly to the step-down unit. This process is known as "fast-tracking" after ambulatory surgery. AIMS: To compare hemodynamic characteristics and recovery profile as per fast-track criteria (FTC) of recovery and postanesthesia discharge scoring system (PADSS) between sevoflurane and desflurane.
MATERIALS AND METHODS: One hundred American Society of Anesthesiologists Class I-II patients aged 20-50 years were randomly divided into two groups. Following anesthesia induction with injection propofol and injection dexmedetomidine airway was secured with i-gel, Group D (n = 50) received desflurane + dexmedetomidine + O2 + N2O and Group S (n = 50) received sevoflurane in place of desflurane. Emergence time was noted and FTC was evaluated in the OR, Score >12 is considered as shifting criteria for ambulatory surgery unit (ASU). PADSS was noted in ASU at an interval of 15 min for 3 h and Score >9 is considered as ready to discharge home.
RESULTS: Response to pain, verbal commands, and spontaneous eye opening in Group D was shorter than that in Group S (P = 0.001). Mean time to achieve FTC score >12 was 15 min in both the groups. Eighty-six percent of patients were ready to go home between 60 and 90 min using PADSS.
CONCLUSION: We concluded that early recovery is faster for desflurane, and there is no difference in ready to go home time between desflurane and sevoflurane.

INTRODUCTION

Day-care surgery as per the International Association of Ambulatory Surgery is “An operation or procedure, an office or outpatient operation/procedure,” where the patient is discharged on the same working day.[12] The main prerequisites for day-care surgery are short duration of procedure, fast recovery from anesthesia, avoiding endotracheal intubation, and use of adjuvants which provide more hemodynamic stability and help in fast recovery from anesthesia.

Nowadays, the concept of balanced anesthesia using different drugs other than anesthetic agents such as benzodiazepines, opioids, neuromuscular blockers, and α2 adrenergic agonists is very popular.

Considering low blood/gas coefficient of sevoflurane and desflurane, fast induction and early recovery were expected from these newer inhalational agents in comparison with traditional agents such as isoflurane and halothane.[3]

For decades, endotracheal intubation and bag and mask ventilation were the mainstays of airway management, but there are many advantages of supraglottic devices over endotracheal tubes as laryngoscopy and muscle relaxant are not required. The ease of insertion and less time for insertion that help in providing secure airway rapidly is the outstanding feature causing less hemodynamic and intraocular pressure changes. It also causes fewer incidences of sore throat and is also less stimulating in reactive airway.[4]

A new and cheaper supraglottic airway device “I-gel”(Intetsurgical Ltd., Wokingham, Berkshire, UK) has been developed.[4] The i-gel is a novel, innovative, easy to insert, single use, latex free, and noninflatable supraglottic airway with “anatomically shaped” cuff which improves the airway seal as the device warms to body temperature, used in anesthesia during spontaneous, and intermittent positive pressure ventilation. It contains both airway and drainage tubes and an integral bite block.[5] Concerns may arise regarding intraoperative awareness as a result of light anesthesia in the effort to fast-track patients at the end of surgery. The bispectral analysis of electroencephalogram (BIS-EEG) has been advocated as a means of preventing awareness during general anesthesia. The BIS-EEG allows practitioners to titrate anesthetics to control levels of consciousness, allowing significantly less drug use, faster emergence, faster postanesthesia recovery times, and improved Postanesthesia Care Unit (PACU) bypass rates.[6]

Dexmedetomidine is a highly selective α2-agonist that has been shown to have sedative, analgesic, and anesthetic sparing effects.[78] In day-care surgery, the newer approach is fast tracking, in which patients are shifted directly from operating room (OR) to ambulatory surgery unit (ASU), for which Aldrete criteria are used as recovery scale in many studies.[9]

The question how long patients should remain in hospital following ambulatory surgery before they can be discharged safely is crucial dimension of future development in this area of care. In year 2003, McGrath and Chung[10] devised a postanesthesia discharge scoring system (PADSS) that objectively assesses fitness for discharge using a scoring system. Using the PADSS, most patients can be discharged within 2 h after surgery. The PADSS was developed at the Toronto Hospital, where it has been used extensively to determine when patients can be discharged home safely.

Many studies have been conducted to evaluate the postoperative recovery characteristics and readiness for discharge such as Aldrete scoring, mini–mental state examination, postanesthesia discharge scoring, and many more. However, there are not much studies which had combined above-mentioned three dimensions for rapid recovery, i.e., less soluble inhaled anesthetics, less airway instrumentation (using i-gel), and finally adjuvants which smoothen extubation by decreasing stress response (dexmedetomidine). This cocktail may provide some benefit over conventional approach.

MATERIALS AND METHODS

After approval from the Institutional Ethical Committee and informed written consent of parents/guardians of the patients, we conducted this double-blind, randomized study in our institute. Patients who do not understand English, consent form was given in vernacular language. Nearly 100 patients of American Society of Anesthesiologist (ASA) Class I or II in the age group of 20–50 years undergoing short surgical procedure under general anesthesia were included in this study. These patients were randomly allocated into two groups of fifty each.

Allocation of groups:

Group S (50): Patients were induced with propofol and maintained with sevoflurane + dexmedetomidine + O2 + N2O without using muscle relaxant

Group D (50): Patients were induced with propofol and maintained desflurane + dexmedetomidine + O2 + N2O without using muscle relaxant.

After doing detailed pre anesthetic check up (PAC), all routine investigation was done.

Inclusion criteria:

Patients of ASA Class I or II in the age group between 20 and 50 years were admitted for day-care surgery irrespective of gender.

Exclusion criteria for potential subjects were:

A history of a significant cardiac, pulmonary, hepatic or renal disease

Chronic drug or alcohol abuse

Morbid obesity

Disabling neuropsychiatric disorder

Hypersensitivity to anesthetics or familial history of malignant hyperthermia

Women who were pregnant or breastfeeding

Patients who refuse to give consent.

On the day of surgery, patients were reassessed preoperatively. After confirming overnight fasting, patients were shifted to operation theater. Multipara monitor was attached. Baseline reading of heart rate (HR), SpO2, noninvasive blood pressure (NIBP), and electrocardiography (ECG) pattern was recorded, and continuous monitoring of vitals was started. Premedication is given to all patients in the form of injection glycopyrrolate 0.2 mg intravenous (IV) + injection ondansetron 4 mg IV 5 min before induction. Induction was done with injection dexmedetomidine 1 μg/kg over 10 min and injection propofol 2–3 mg/kg airway was secured by i-gel. Maintenance of anesthesia was achieved with sevoflurane/desflurane and dexmedetomidine infusion 0.5 μg/kg/h. Continuous monitoring of NIBP, SpO2, HR, ECG, pulse rate, and BIS was done. Dial concentration was adjusted to maintain BIS in the range of 40–50. In case of intraoperative bradycardia, i.e., HR <60 beats/min or hypotension (systolic blood pressure [SBP] <90 mmHg or mean blood pressure <60 mmHg), i.e., dial concentration and dexmedetomidine, infusion rate will be adjusted accordingly. Injection atropine and injection ephedrine were used for resistant cases. Ten minutes before the start of skin closure, injection paracetamol infusion was started at a dose of 15 mg/kg for analgesia. Dexmedetomidine infusion stopped 5 min before completion of surgery. After completion of surgery, all anesthetic gases were stopped, i-gel was removed 100% O2 given, and emergence time was noted.

The question how long patients should remain in hospital following ambulatory surgery before they can be discharged safely is crucial dimension of future development in this area of care. In our study, we used fast-track criteria (FTC) for recovery and PADSS for discharge. FTC score >12 is considered as shifting criteria for ASU. PADSS was noted in ASU at an interval of 15 min for 3 h and Score >9 is considered as ready to discharge home.

RESULTS

A total of 100 patients were recruited for the study and 50 patients were allocated to each group. Sample size was calculated at view at most 5% risk, with minimum 80% power, and 5% significant level (significant at 95% confidence interval). There was no premature study withdrawal due to failure of surgery to proceed as planned or the development of complications hindering the assessment of study variables. Both the groups were comparable demographically and statistically nonsignificant in terms of mean age and sex of patients in both groups. Mean duration of surgery was also comparable in both groups. Baseline, at the time of securing airway, and intraoperative hemodynamic variables such as HR, blood pressure (BP), and oxygen saturation were monitored. There was no statistical difference in desflurane and sevoflurane groups. Another important finding observed in our study was no increase in HR and BP at the time of securing airway when compared to baseline BP.

The time to achieve response to painful stimuli, response to verbal commands, and spontaneous eye opening were measured from time of termination of anesthetic gases. Time (mean ± standard deviation [SD] minutes) for response to painful stimuli, response to verbal commands, and spontaneous eye opening was 5.38 ± 1.04, 5.96 ± 1.14, and 6.84 ± 1.05 in Group S (sevoflurane); in Group D (desflurane), it was 3.66 ± 0.96, 4.64 ± 1.04, and 5.62 ± 1.08, respectively [Table 1 and Figure 1]. All these parameters were achieved in significantly less time (P < 0.0001) in Group D (desflurane) as compared to Group S (sevoflurane), thus suggesting that desflurane had a faster recovery than sevoflurane. The mean time to achieve fast-track score of >12 was less in Group D (12.8 ± 2.88 min) as compared to Group S (12.9 ± 4.52 min), but it was statistically insignificant. There was no significant difference in mean PADSS score at different time intervals in both the groups [Table 2]. Nearly 7% of patient in 15–45 min, 76% in 60–120 min, and 17% in 135–180 min were ready to go home. In total, 83% patients were ready to go home in 2 h [Figure 2]. Pain was observed in seven patients in Group D and nine patients in Group S. The treatment given was injection diclofenac 75 mg intramuscular. It was found to be statistically insignificant. Nausea and vomiting was present in four patients in Group D and three patients in Group S. The treatment given was ondansetron IV 4 mg; it was found to be statistically insignificant.

Table 1

Emergence characteristics in Group S and Group D

Figure 1

Emergence characteristics in Group S and D

Table 2

Mean postanaesthesia discharge scoring system in Group S and Group D

Figure 2

Time to assess PADSS score

DISCUSSION

Multidimensional benefits to the patient, hospital, and national economy are the driving forces behind the changing scenario on the horizon of day-care surgery, and it has facilitated the rapid rise in ambulatory surgery worldwide. With the availability of rapid, short-acting anesthetic, analgesic as well as improved monitoring devices, it has been possible to minimize the adverse effects of anesthesia on the recovery process. When anesthetic inhalational agent's dose is calculated according to BIS readings, without endotracheal intubation and without the use of muscle relaxants, it adds to many benefits to patients which was the main focus of our study.

In our study, HR, SBP, and DBP remained stable during surgery and also the intergroup comparison was statistically nonsignificant, and this comes in agreement with the study conducted by Jones et al.[11]

Another important finding observed in our study was no increase in HR and BP at the time when secured airway when compared to baseline BP (mean ± SD mmHg) and HR (mean ± SD beats/min). Our study is also in accordance with a study done by Rao et al.[12] They concluded that dexmedetomidine provided a stable hemodynamic profile in the perioperative period and a blunted pressor response to intubation and extubation.

The time to achieve response to painful stimuli, response to verbal commands, and spontaneous eye opening were measured from the time of termination of anesthetic gases. All these parameters were achieved in significantly less time (P < 0.0001) in Group D (desflurane) as compared to Group S (sevoflurane), thus suggesting that desflurane had faster recovery from anesthesia than sevoflurane.

Our study is also in accordance with Heavner et al.[13] They concluded that elderly patients after a variety of surgical interventions’ early recovery are faster following desflurane versus sevoflurane anesthesia. Our study is also in accordance with Erk et al.[14] They compared the effects of desflurane, sevoflurane, and propofol on recovery characteristics and postoperative nausea and vomiting (PONV) in laparoscopic cholecystectomy; they concluded early recovery was significantly fast in desflurane group but no statistically significant in late recovery.

The mean time to achieve fast-track score of >12 was less in Group D as compared to Group S, but it was statistically insignificant. The fast-track score at 5, 10, 15, 20, and 25 min was also statistically insignificant between Group D and Group S. This is in accordance with the study conducted by Gonul and Ozer.[15] who showed that there was no significant variation in FTC score between sevoflurane and desflurane at 5, 10, and 15 min after extubation.

Our study was in concordance with the study done by Chung[16] which concluded that PADSS home-readiness criteria were satisfied in 19% of patients at 60 min, 60% at 90 min, and 86% at 120 min. The majority (95.6%) of patients achieved a PADSS score >9 within 3 h after anesthesia. Only 4.4% of patients had to stay in the ambulatory unit >3 h after anesthesia. Our study is also supported by a study done by Jindal et al.[17] They concluded that there was an insignificant difference in mean time to achieve PADSS score >9 between desflurane (188.40 ± 22.30 min) and sevoflurane (193.20 ± 22.60 min) groups.

The reason for delayed achieving PADSS score >9 in 16 patients was the type of surgery due to which they were not able to walk such as hydrocele and perineal abscess drainage.

The incidence of postoperative complications (pain and PONV) was also similar in both the groups. This was in contrast to a study by Karlsen et al.[18] who found that the PONV (24 h in PACU and ward) was higher in the desflurane group (67%) than that in sevoflurane group (36%). This difference in PONV can be explained on the basis that we observed the patient only till they achieved necessary PADSS for discharge, i.e., maximum duration was 3 h.

Limitations

As far as limitations of our study are concerned, main limitation was we had not done end-tidal CO2 monitoring and other was that we observed the patients until they achieved necessary PADSS for discharge, i.e., maximum duration was 3 h. Hence, we were not able to comment on delayed complications.

Thus, to conclude, both the inhalational anesthetics, i.e., sevoflurane and desflurane give comparable results as far as time to home readiness is concerned while emergence is fast with desflurane. Use of PADSS has limitations in procedures which prevents early ambulation such as surgery for hydrocele and perineal abscess, so there is scope for some modification in PADSS score. It should be considered that these anesthetics have no differences in terms of late recovery, PONV, and discharge from the hospital.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.