Non‑intubated general anesthesia with a supraglottic airway for heart transplantation: a preliminary cohort study of feasibility and enhanced recovery

Abstract

Background

Endotracheal intubation (EI) with mechanical ventilation has been the long-standing standard of care for general anesthesia of heart transplantation. The aim of this study is to evaluate the feasibility and recovery impact of a non‑intubated anesthesia (NIA) strategy using a supraglottic airway.

Methods

This study involved a single-center retrospective cohort (February 2023–August 2025). Recipients who were managed with NIA were compared with those receiving conventional EI. Primary outcomes were time to oral intake and time to first mobilization; secondary outcomes included estimated blood loss, intraoperative variables, vasoactive requirements, and intensive care unit length of stay.

Results

Seventeen recipients were included in the analysis (NIA, n=8; EI, n=9). NIA was associated with earlier oral intake [3.8 (3.5–5.0) vs. 27 (22–65) h; P=0.001], earlier mobilization [1.5 (1.3–2.0) vs. 4.0 (4.0–7.0) days; P=0.001], and lower estimated blood loss [375 (300–450) vs. 800 (500–1,000) mL; P=0.02]. Cardiopulmonary bypass, cross‑clamp, operation, and cold ischemia times trended shorter with NIA, but the differences were not statistically significant. No statistically significant differences were observed in intraoperative vasoactive-inotropic score or intraoperative vasoactive-inotropic dose. One planned NIA case converted to EI.

Conclusions

In selected recipients, non‑intubated general anesthesia heart transplantation with a supraglottic airway is feasible and associated with accelerated recovery. Prospective evaluations are warranted.

Highlight box.

Key findings

• This preliminary cohort study is the first to investigate the use of non-intubated general anesthesia with a supraglottic airway device in patients undergoing heart transplantation.

• This non-intubated general anesthesia technique was associated with earlier postoperative oral intake and mobilization, reduced intraoperative blood loss in heart transplant recipients.

What is known and what is new?

• Non-intubated anesthesia has been reported in pediatric combined heart-lung transplantation to reduce pulmonary complications and accelerate recovery. In open-heart surgery, there are only case reports and small series. This existing evidence suggests the potential feasibility of non‑intubated anesthesia (NIA) in heart transplantation.

• In carefully selected recipients managed within a standardized pathway and with a ready conversion plan, NIA heart transplantation using a supraglottic airway appears feasible and confers early functional advantages—notably earlier oral intake and mobilization and less bleeding—without evidence of increased vasoactive support.

What is the implication, and what should change now?

• The use of non-intubated general anesthesia with a supraglottic airway device appears feasible in heart transplantation and may confer early functional benefits.

• These hypothesis-generating results warrant prospective validation to clearly define the patient population most likely to benefit, confirm the safety of this approach in larger-scale applications, and quantify gains in resource utilization and patient-centered outcomes.

Introduction

Background

Heart transplantation is routinely performed under general anesthesia with endotracheal intubation (EI) (1-3). EI can contribute to airway trauma and ventilator-related lung injury and may delay recovery (4,5). Optimized airway management may offer significant benefits in cardiac transplantation. A previous study has indicated that ultra-fast-track extubation in the operating room can reduce infectious complications, ventilator-associated pneumonia, and atelectasis, without increasing patient mortality, demonstrating a favorable safety profile (6). Our pioneering “tubeless” thoracoscopic surgery, which integrates regional nerve blocks and preserves spontaneous breathing while avoiding EI, has been widely adopted (7). Therefore, non-intubated anesthesia (NIA) using a supraglottic airway may mitigate these issues. We report our preliminary experience comparing NIA versus EI in a consecutive cohort.

Rationale and knowledge gap

We recently successfully performed a combined heart-lung transplantation under NIA in a 15-year-old male patient with pulmonary hypertension and right heart failure, with satisfactory postoperative recovery (8). This case demonstrates the conceptual feasibility of NIA in cardiac transplantation. In the field of cardiothoracic surgery, spontaneous ventilation techniques have shown advantages in reducing airway instrumentation and mechanical ventilation, potentially improving patient outcomes (7,9-11). The tubeless thoracoscopic surgery and anesthesia protocol, primarily utilizing a laryngeal mask airway combined with targeted nerve blocks, has been proven to mitigate airway trauma, reduce systemic inflammatory response, and accelerate recovery (7,9). A previous case report described the successful use of non-intubated anesthesia with intravenous sedation and nerve blocks in a 41-year-old patient undergoing atrial septal defect repair (12). As optimized airway management and fast-track protocols gain widespread use to reduce complications after cardiac surgery, our technique of supraglottic airway-based NIA emerges as the logical next step—pushing the boundaries of enhanced recovery in the perioperative period.

Objective

Given the potential benefits of optimized airway management for heart transplantation, our center has employed NIA in lung transplantation since 2023. This study was consequently designed to evaluate the safety and impact on postoperative recovery of NIA in patients undergoing heart transplantation. To our knowledge, this represents the first preliminary cohort study investigating the use of NIA with a supraglottic airway for general anesthesia in heart transplantation. We present this article in accordance with the TREND reporting checklist (available at https://jtd.amegroups.com/article/view/10.21037/jtd-2025-aw-2169/rc).

Methods

Study design and setting

This is a single‑center retrospective cohort study of heart transplants that were performed between February 2023 and August 2025. Patients from The First Affiliated Hospital of Guangzhou Medical University since February 2023 were categorized by final airway strategy (NIA with a supraglottic airway vs. EI). Beginning in November 2024, NIA was considered for suitable candidates. Suitable candidates for NIA in heart transplantation were those with controllable surgical duration, no evidence of a difficult airway, relatively stable hemodynamics, and no history of active gastroesophageal reflux or swallowing disorder. Contraindications included anticipated difficult airway, severe pulmonary hypertension, expected surgical time >10 hours, severe preoperative pulmonary infection or pulmonary edema, or patients already intubated preoperatively. One intended NIA case converted to EI and was analyzed with EI. The study was conducted in accordance with the Declaration of Helsinki and its subsequent amendments and was approved by the ethics committee of The First Affiliated Hospital of Guangzhou Medical University (No. ES-2025-137-02). Informed consent for data usage was obtained from all participants. The flowchart of this study is shown in Figure 1.

Figure 1.

Flowchart of the study. EI, endotracheal intubation; NIA, non-intubated anesthesia.

Eligibility, selection, and perioperative care

Exclusion criteria for heart transplantation included preoperative intubation, severe pulmonary hypertension, pulmonary edema/disease and severe hepatic/renal dysfunction, and other surgical contraindications, including severe active infection, extracardiac malignancy, history of substance abuse, severe peripheral vascular or cerebrovascular disease.

All recipients underwent median sternotomy with cardiopulmonary bypass (CPB) and standard postoperative immunosuppression.

Anesthesia and surgery procedures

NIA pathway

Induction was performed with midazolam, sufentanil, etomidate, and rocuronium. After induction, a supraglottic airway was placed, and ventilation was initiated in high-frequency SIMV mode with a tidal volume of 4–8 mL/kg and a respiratory rate of 12–20 breaths/min. Maintenance anesthesia consisted of continuous infusions of remifentanil (0.1–0.2 µg/kg/min) and dexmedetomidine (0.2–0.7 µg/kg/h), combined with target-controlled infusion (TCI) of propofol at a target plasma concentration of 1–2 µg/mL; sufentanil and sevoflurane were added if clinically indicated. Rocuronium (0.3 mg/kg) could be administered intraoperatively as needed to facilitate surgical conditions. Ultrasound-guided bilateral intercostal nerve blocks (T3–T8) were performed before skin preparation and draping, using 0.375% ropivacaine combined with 1% lidocaine, 4 mL per intercostal space, in a single administration. Alternatively, bilateral transversus thoracis muscle plane blocks could be performed, with the same drug combination at 20 mL per side. For sternotomy analgesia, due to the synergistic effect of the nerve block, an additional bolus of sufentanil (0.2–0.5 µg/kg) and rocuronium (0.3 mg/kg) was administered immediately before sternotomy. No further neuromuscular blockade was given after induction unless required for surgical conditions. The supraglottic airway was removed in the operating room once the patient was fully awake, meeting the following criteria: adequate spontaneous breathing, stable hemodynamics, core temperature ≥36 ℃, no active bleeding, and full consciousness with appropriate responses. Conversion to EI was performed if the post-bypass oxygenation index (PaO₂/FiO₂) was <150 or if uncorrectable hypercapnia or acidosis occurred.

EI pathway

The EI pathway used identical induction and maintenance except for tracheal intubation; extubation was performed in the intensive care unit (ICU) when criteria were met.

Arterial blood gas was monitored via a radial artery line. Samples were obtained every 30–60 minutes, and more frequently if clinically indicated. Perfusion management was identical in both NIA and EI groups, with no procedural differences.

Outcomes analysis

Primary outcomes were time to oral intake (hours) and time to first mobilization (days). Secondary outcomes included estimated blood loss (EBL), intraoperative times, vasoactive‑inotropic score (VIS) and dose (VID), ventilation duration (EI), ICU length of stay, and complications.

Statistical analysis

Normality was assessed using the Shapiro-Wilk test. Continuous variables were compared using Student’s t-test or the Mann-Whitney U test, as appropriate. Categorical variables were analyzed using Fisher’s exact test. A two-sided P value <0.05 was considered statistically significant. All analyses were performed using SPSS version 25.0.

Results

Cohort and baseline characteristics

Seventeen recipients were analyzed (8 in the NIA group and 9 in the EI group) (Table 1). Groups were broadly similar for sex, age, body mass index/body surface area, and etiology. The EI group had numerically higher preoperative acuity [more vasoactive/intra-aortic balloon pump (IABP) support; more patients in Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) class 1–3], without statistical significance.

Table 1. Baseline clinical and demographic characteristics.

Variable	EI (n=9)	NIA (n=8)	P
Female	2 (22.2)	5 (62.5)	0.15
Age, years	50±16	37±17	0.14
BMI, kg/m2	20.7±5.2	22.3±2.8	0.44
BSA, m2	1.60±0.21	1.62±0.14	0.84
Diagnoses			0.46
Dilated cardiomyopathy	7 (77.8)	5 (62.5)
Arrhythmogenic cardiomyopathy	1 (11.1)	2 (25.0)
Ischemic cardiomyopathy	1 (11.1)	0
Congenital heart disease	0	1 (12.5)
ICD implanted	3 (33.3)	1 (12.5)	0.58
IABP support (preop)	2 (22.2)	0	0.47
Preop vasoactive use	6 (66.7)	2 (22.2)	0.15
INTERMACS class 1–3	6 (66.7)	2 (25.0)	0.22

Data are presented as n (%) or mean ± standard deviation. BMI, body mass index; BSA, body surface area; EI, endotracheal intubation; IABP, intra-aortic balloon pump; ICD, implantable cardioverter defibrillator; INTERMACS, Interagency Registry for Mechanically Assisted Circulatory Support; NIA, non-intubated anesthesia.

Intraoperative management and recovery

EBL was lower with NIA [375 (300–450) vs. 800 (500–1,000) mL; P=0.02] (Table 2). CPB and aortic cross-clamp time metrics trended shorter with NIA but were not statistically different. In NIA cases, the supraglottic airway was removed in the operating room (mean 19.4±13.5 min). EI patients had 24 (17–118) h of postoperative ventilation. Oral intake [3.8 (3.5–5.0) vs. 27 (22–65) h; P=0.001] and mobilization [1.5 (1.3–2.0) vs. 4.0 (4.0–7.0) days; P=0.001] occurred earlier with NIA. ICU stay was numerically shorter with NIA (4.8±1.7 vs. 7.2±4.6 days; P=0.17).

Table 2. Intraoperative and postoperative outcomes.

Outcomes	EI (n=9)	NIA (n=8)	P
CPB time, min	239 [218–255]	175 [162–222]	0.054
Aortic cross‑clamp, min	101.5±21.9	82.6±21.7	0.10
Cold ischemia, min	196±47	165±43	0.19
Estimated blood loss, mL	800 [500–1,000]	375 [300–450]	0.02
Intraoperative VIS	16.7±6.9	13.8±7.7	0.43
Intraoperative VID, mg/kg	2.8±1.3	2.4±1.2	0.54
Mechanical ventilation, h	24 [17–118]	–	–
Oral intake, h	27 [22–65]	3.8 [3.5–5.0]	0.001
Mobilization, days	4.0 [4.0–7.0]	1.5 [1.3–2.0]	0.001
ICU length of stay, days	7.2±4.6	4.8±1.7	0.17
Postoperative VID, mg/kg	27.1 [13.0–38.5]	26.1 [15.1–46.4]	0.77
Duration of vasoactive use, days	3.0 [3.0–14.5]	3.5 [3.0–8.0]	0.81

Data are presented as median [interquartile range] or mean ± standard deviation. CPB, cardiopulmonary bypass; EI, endotracheal intubation; ICU, intensive care unit; NIA, non-intubated anesthesia; VID, vasoactive-inotropic dose; VIS, vasoactive-inotropic score.

Discussion

Principal findings

In this preliminary cohort comparing NIA with a supraglottic airway against conventional EI for orthotopic heart transplantation, we identified three robust signals. First, time to oral intake and time to first mobilization were markedly shorter with NIA [3.8 (3.5–5.0) h and 1.5 (1.3–2.0) days, respectively], consistent with an enhanced‑recovery effect. Second, EBL was significantly lower with NIA [median 375 (300–450) vs. 800 (500–1,000) mL]. Third, hemodynamic stability and vasoactive requirements were comparable between groups, and only one NIA candidate required intraoperative conversion to EI. Other operative time variables (CPB, cross‑clamp, total operative, and cold ischemia times) trended shorter without statistical significance—likely reflecting both clinical and sample‑size factors. Collectively, these findings suggest that NIA is feasible in carefully selected transplant recipients and may accelerate early postoperative rehabilitation without compromising intraoperative control.

Relation to prior work and what this adds

Fast‑track cardiac anesthesia and immediate or early extubation after cardiac surgery—including transplant in selected settings—are supported by prior literature and are cornerstones of Enhanced Recovery After Surgery (ERAS)inspired pathways (13-18). Our experience extends this trajectory by evaluating deliberate avoidance of tracheal intubation via a supraglottic airway in isolated heart transplantation, rather than merely expediting extubation after EI. To our knowledge, this is the first case‑series to report such a strategy in this procedure, bridging the gap between fast‑track paradigms and fully non‑intubated conduct of complex cardiac surgery. The magnitudes of benefit we observed—especially for oral intake and mobilization—are directionally concordant with ERAS principles, while the lack of excess vasoactive support or instability indicates that physiologic tolerance of NIA can be achieved even in this high‑acuity context.

Potential mechanisms underlying accelerated recovery

Several, likely synergistic, mechanisms may explain the observed earlier functional recovery with NIA (14,19-22): (I) Airway/respiratory mechanics: avoiding tracheal instrumentation reduces mucosal trauma and airway edema, which can hinder early swallowing and mobilization; the supraglottic approach also facilitates lighter planes of anesthesia toward the end of surgery, expediting emergence. (II) Lower exposure to neuromuscular blockade and volatile agents: our pathway minimized additional muscle relaxant beyond induction; together with opioid‑sparing maintenance and pre‑emptive intercostal nerve block, this likely improved early neuromuscular function and preserved protective airway reflexes, supporting earlier oral intake and physical therapy engagement. (III) Hemodynamic steadiness without higher vasoactive burden: comparable intra‑ and postoperative vasoactive indices between groups indicate that avoiding intubation did not incur a penalty in circulatory control. (IV) Bleeding signal: lower EBL in NIA may relate to reduced airway stimulation and fewer swings in intrathoracic pressure as the patient transitions off CPB. Additionally, because surgical and CPB durations were shorter in NIA, the team could proceed to chest closure sooner, allowing earlier intraoperative hemostasis assessment and intervention. This timing advantage may have contributed to more efficient bleeding control. Selection effects cannot be excluded and warrant confirmation in larger, adjusted cohorts.

Safety, patient selection, and conversion strategy

Safety in non‑intubated transplant anesthesia hinges on three pillars: (I) patient selection; (II) standardized intraoperative thresholds for conversion to EI; and (III) team readiness to convert rapidly. In our program, NIA selection criteria generally excluded preoperative intubation, severe pulmonary hypertension/edema and major end‑organ dysfunction. With this approach, no signal of excess hemodynamic or ventilatory instability was observed, and no re‑intubations were required postoperatively in the NIA group. One planned NIA case required intraoperative conversion for instability and was managed uneventfully thereafter—underscoring that a low, pre‑specified conversion threshold is integral to safe deployment. From a ventilatory perspective, the supraglottic airway must reliably achieve leak pressures compatible with target tidal volumes and end-tidal carbon dioxide partial pressure (ETCO₂) during non‑intubated maintenance and separation from CPB. Routine intraoperative capnography and blood‑gas surveillance, readiness to decompress the stomach if needed, and hemodynamically tolerant anesthetic depth are practical safeguards. Our median time to device removal in the operating room timing (≈20 minutes after closure) aligns with these principles and likely contributed to the early‑recovery profile.

Clinical implications

If validated prospectively, NIA with a supraglottic airway could be an ERAS‑compatible default for a defined subset of transplant recipients—those without severe pulmonary hypertension or preoperative ventilatory compromise and with stable preoperative physiology. The functional gains we observed (earlier oral intake and mobilization) are clinically meaningful because they often translate into earlier rehabilitation milestones, more rapid transition to goal‑directed immunosuppression and nutrition, and possibly shorter ICU or hospital stays. Our data already show a numerically shorter ICU stay with NIA; however, sample size limits definitive inference. Resource utilization and cost advantages are plausible given less bleeding, earlier mobilization, and avoidance of ventilator‑associated care, but require formal cost‑effectiveness analyses.

Strengths and limitations

Strengths include the first systematic experience of a non‑intubated primary airway strategy in isolated heart transplantation; a standardized anesthetic pathway emphasizing opioid‑sparing and regional analgesia; and intention‑to‑treat handling of the single conversion case. Reporting both functional recovery endpoints and hemodynamic surrogates (VIS/VID) provides a balanced view of benefit and risk. Limitations include a small, single‑center, retrospective design with potential confounding by indication—indeed, the EI group had numerically higher acuity (more preoperative vasoactives and IABP). Some variables were summarized by medians without patient‑level data, limiting effect‑size estimation; complications were not powered for between‑group testing; and vasoactive reporting combined VIS with an institution‑specific VID aggregate. Unmeasured factors (e.g., donor‑recipient size match, pulmonary function metrics, analgesic exposure) may have influenced outcomes.

Future directions

Three complementary paths seem most informative: (I) a prospective, multicenter registry capturing standardized selection criteria, airway device specifications, ventilatory targets, and pre‑specified conversion triggers; (II) controlled comparative designs (propensity‑matched or inverse probability of treatment weighting (IPTW)‑adjusted cohorts; ultimately a randomized feasibility trial) focusing on functional recovery, pulmonary complications, transfusion needs, and safety; (III) health‑economics and patient‑reported outcomes to quantify value and patient experience alongside clinical safety.

Conclusions

In carefully selected recipients managed within a standardized pathway and with a ready conversion plan, NIA heart transplantation using a supraglottic airway appears feasible and confers early functional advantages—notably earlier oral intake and mobilization and less bleeding—without evidence of increased vasoactive support. These hypothesis‑generating results warrant prospective validation to define the population most likely to benefit, confirm safety at scale, and quantify resource and patient‑centered gains.

Supplementary

The article’s supplementary files as

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. The study was conducted in accordance with the Declaration of Helsinki and its subsequent amendments. The study was approved by the ethics committee of The First Affiliated Hospital of Guangzhou Medical University (No. ES-2025-137-02). Informed consent was obtained from all individual participants.

Data Sharing Statement

Available at https://jtd.amegroups.com/article/view/10.21037/jtd-2025-aw-2169/dss

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DOI: 10.21037/jtd-2025-aw-2169