European Journal of Cardiovascular Medicine

Day care or ambulatory surgery has become an integral part of modern surgical practice, offering the benefits of reduced hospital stay, lower healthcare costs, and improved utilization of hospital resources without compromising patient safety or clinical outcomes [1]. The concept of operating and discharging a patient on the same day is particularly beneficial in high-volume centers and developing healthcare systems where efficiency is paramount.

The anaesthetic technique used plays a vital role in determining the success of ambulatory procedures. Historically, general anaesthesia was often avoided in these settings due to its association with delayed recovery and increased risk of postoperative complications [2]. However, the development of short-acting agents like Propofol and the refinement of inhalational agents such as Isoflurane have significantly improved outcomes [3, 4].

Propofol has become a popular choice for total intravenous anaesthesia (TIVA), owing to its rapid onset and offset, minimal postoperative nausea and vomiting (PONV), and smoother psychomotor recovery profile [5,6]. Isoflurane remains a widely used volatile anaesthetic, known for its cardiovascular stability and reliability, although it has been associated with prolonged recovery times in some studies [7].

The decision between TIVA with Propofol and inhalational maintenance with Isoflurane often comes down to the expected speed of recovery and readiness for discharge. Rapid recovery in day care surgery not only improves patient satisfaction but also supports hospital throughput, making this comparison clinically relevant [8].

This study was conducted to assess phase I and phase II recovery times between Propofol-based TIVA and Isoflurane-based inhalational anaesthesia in patients undergoing minor elective day care surgeries.

This was a prospective, randomized, single-blinded comparative study conducted over a period of one year, from June 2023 to May 2024, at the Department of Anaesthesia, Guntur Medical College. Institutional ethics committee approval was obtained prior to study commencement. Written informed consent was obtained from all participants.

Based on previous studies comparing recovery times between Propofol and Isoflurane [1,2], with an estimated standard deviation of 10 minutes for Phase II recovery and a minimum clinically relevant difference of 8 minutes, the required sample size was calculated as 36 per group (α = 0.05, β = 0.20). Considering potential dropouts, a final sample of 80 patients was enrolled (40 per group).

Inclusion Criteria

• Adult patients aged 18–50 years
• American Society of Anesthesiologists (ASA) physical status I or II
• Scheduled for elective, minor, day care surgeries (head, neck, breast, or upper limbs)
• Estimated surgical duration less than 90 minutes
• Ability to ambulate independently and follow post-anaesthesia instructions

Exclusion Criteria

• Patients unwilling to participate
• ASA physical status ≥ III
• Major surgical procedures
• History of obstructive sleep apnoea, difficult airway, or neuropsychiatric disorders
• Known allergy to Propofol or Isoflurane

Patients were randomly allocated into two groups (n = 40 each) using computer-generated random numbers placed in sealed opaque envelopes: Group P: Received Propofol-based Total Intravenous Anaesthesia (TIVA) and Group I: Received Isoflurane-based inhalational maintenance.

All patients were pre-medicated with intravenous glycopyrrolate (5 µg/kg) and fentanyl (2 µg/kg). Standard monitors were applied (ECG, non-invasive BP, SpO₂), and baseline vitals recorded. Induction was done with Propofol 2 mg/kg IV in both groups. A size-appropriate Laryngeal Mask Airway (LMA) was inserted after loss of verbal contact and confirmed for correct placement.

Group P (Propofol TIVA): Anaesthesia was maintained using Propofol infusion via a syringe pump with a manual stepped regimen:

• 200 µg/kg/min for 10 minutes
• 167 µg/kg/min for 20 minutes
• 133 µg/kg/min for 30 minutes
• 100 µg/kg/min maintenance until end of surgery Spontaneous ventilation was supported with a Bain circuit.

Group I (Isoflurane): Anaesthesia maintenance was with Isoflurane. Inspired concentration of Isoflurane was titrated between 0.6%–1.2% based on patient response. Spontaneous breathing was maintained throughout.

Vital parameters including heart rate, non-invasive blood pressure, SpO₂, and ECG were monitored every 5 minutes. Anaesthesia was discontinued at the time of skin closure, and this was considered ‘time zero’ for recovery measurement.

Recovery Assessment

Recovery was evaluated in two phases:

• Phase I Recovery: Time from anaesthetic discontinuation to achievement of Aldrete score ≥ 9
• Phase II Recovery (Home Readiness): Time from anaesthetic discontinuation to PADSS score ≥ 9

All recovery assessments were performed by an anaesthesiologist blinded to group allocation.

Data analyzed with SPSS software (25.0). Quantitative variables were expressed as mean and compared using the unpaired Student’s t-test. P-value less than 0.05 was considered statistically significant.

In this study, 80 individuals were divided into 2 equal groups, (n=40 in each group). Baseline parameters were comparable between the groups.

Table 1: Baseline Characteristics of Patients

There were no statistically significant differences in age, weight, or gender distribution between the two groups.

Table 2: Duration of Surgery and Recovery Times

Phase I recovery times were similar across both groups. However, Phase II recovery (home readiness) was significantly faster in the Propofol group compared to the Isoflurane group.

Table 3: Distribution of Recovery Milestones

A higher proportion of patients in the Propofol group achieved Phase II recovery within 45 minutes, compared to only a few in the Isoflurane group.

Table 4: Adverse Events Observed

Propofol was associated with fewer postoperative complaints, particularly in terms of nausea and delayed awakening.

Day care or ambulatory anaesthesia is increasingly favoured for elective minor surgeries due to its advantages in cost-effectiveness, patient convenience, and reduced hospital stay. The key to a successful day care anaesthetic technique lies in ensuring a smooth induction, stable intraoperative course, and rapid recovery with minimal side effects. In this study, we compared the recovery profiles of Propofol-based TIVA and Isoflurane-based inhalational anaesthesia, with a particular focus on discharge readiness (Phase II recovery).

Our findings demonstrate that while both agents yielded similar Phase I recovery times, Propofol significantly outperformed Isoflurane in Phase II recovery. This suggests that although immediate awakening may not differ substantially, Propofol facilitates faster return to baseline function and home readiness. These results align with earlier studies which report quicker discharge profiles with TIVA agents, particularly Propofol, in ambulatory settings [9, 10].

The pharmacokinetic profile of Propofol contributes to its efficiency. It undergoes rapid redistribution and hepatic metabolism, resulting in minimal residual sedation, even after longer infusions [11]. Conversely, Isoflurane, with its higher lipid solubility, tends to accumulate in adipose tissues, particularly with increasing anaesthetic duration, thereby prolonging its washout and delaying full recovery [12].

Interestingly, our findings also correlate with a recent study by Mahdavi et al., who observed that patients anaesthetised with Propofol were discharged significantly earlier than those receiving Isoflurane after short ENT procedures, despite similar intraoperative stability [13]. Likewise, Yilmaz et al. found that TIVA led to better cognitive and psychomotor recovery compared to inhalational agents in outpatient laparoscopic surgeries [14].

Regarding postoperative complications, Propofol was associated with a lower incidence of nausea and vomiting, consistent with its known antiemetic properties [15]. In contrast, patients in the Isoflurane group experienced more PONV events, although none were severe. This further strengthens the case for choosing Propofol when patient comfort and early discharge are priorities.

Our study also aligns with a meta-analysis by Punjasawadwong et al., which highlighted that TIVA significantly reduces the incidence of PONV and improves patient satisfaction in ambulatory settings compared to volatile anaesthetic [16]. Moreover, the manual stepped infusion regimen we used for Propofol proved to be a practical and effective alternative to target-controlled infusion pumps, especially in resource-limited settings [17].

The distribution of surgical duration, age, weight, and gender across groups was statistically comparable, minimizing potential confounding. However, a small limitation of this study is that we did not evaluate long-term outcomes such as postoperative cognitive function or delayed side effects, which may merit further investigation.

From a resource utilization perspective, although Isoflurane is often considered more economical in terms of per-unit cost, the extended recovery time may increase indirect hospital costs, including staffing and recovery room usage [18]. Therefore, Propofol may provide greater overall efficiency in high-throughput day care settings.

In this comparative study evaluating Propofol-based total intravenous anaesthesia and Isoflurane-based inhalational anaesthesia for minor outpatient surgeries, both techniques offered similar early recovery times. However, Propofol demonstrated a significantly shorter Phase II recovery period, translating into earlier discharge readiness and less postoperative complications.

Given its favorable recovery profile and enhanced patient comfort, Propofol appears to be the more suitable choice for ambulatory anaesthesia in elective short-duration surgeries, especially in high-throughput environments aiming to optimize turnover without compromising safety.

Future studies may focus on long-term patient satisfaction, cost-analysis in different healthcare models, and cognitive recovery parameters to further support the findings of this study.

ACKNOWLEDGEMENTS: The authors would like to acknowledge the support given by the staff while conducting this study.

CONFLICTS OF INTEREST: None declared.

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