Comparison of Acute Airway/Respiratory Complications and Intervention Requirements in Extubations Performed During On-Hours Versus Off-Hours

Comparison of Acute Airway/Respiratory Complications and Intervention Requirements in Extubations Performed During On-Hours Versus Off-Hours: A Prospective Observational Cohort Study

Perioperative airway/respiratory complications are a major driver of morbidity and mortality. While UK audits NAP4 and NAP7 extensively examined major critical events (e.g., cardiac arrest), prospective standardized data on acute, more frequent extubation-phase complications-such as desaturation, laryngospasm, obstruction, bronchospasm, and aspiration-remain scarce. Off-hours procedures carry additional risks related to increased workload, reduced senior supervision, and clinician fatigue, though current evidence is inconclusive and requires further human-factors research using validated tools like the Karolinska Sleepiness Scale (KSS). This prospective cohort study at Kocaeli City Hospital aims to compare the incidence of acute airway/respiratory complications and intervention requirements during extubation and the first 30 minutes post-extubation between on-hours (08:00-16:00) and off-hours (>16:00). Notably, this will be the first prospective observational study to specifically test NAP7's off-hours risk findings at the extubation stage, with the goal of strengthening patient safety and guiding institutional quality improvement.

Study Overview

• Status: Recruiting
• Conditions: Extubation; Airway Complication of Anaesthesia; Extubation Failures
• Intervention / Treatment: Procedure: Extubation; Other: Survey/Questionnaire Administration

Detailed Description

Perioperative airway and respiratory complications remain a leading cause of significant morbidity and mortality in anaesthetic practice, as rigorously highlighted by the Royal College of Anaesthetists and Difficult Airway Society's 4th National Audit Project (NAP4), which comprehensively mapped the epidemiology of major airway events across anaesthesia, intensive care, and emergency departments, while particularly emphasising the disproportionately severe outcomes in emergency surgeries and non-theatre settings, as well as the pivotal role of system-level and team-related factors in shaping these adverse events. Building upon this foundation, the recently published analyses from the 7th National Audit Project (NAP7) have further substantiated that airway and respiratory complications-most notably laryngospasm, failed airway management, and pulmonary aspiration-account for a considerable proportion of perioperative cardiac arrests, reaffirming the persistent vulnerability of the airway across the entire perioperative continuum. Nevertheless, despite the invaluable contributions of NAP4 and NAP7, these landmark audits are fundamentally designed as national surveillance programmes focused on catastrophic endpoints such as major airway incidents and cardiac arrest; consequently, they have not provided prospective, standardised, and granular data on the much more frequently encountered acute airway and respiratory events that occur specifically during the extubation phase-including desaturation, laryngospasm, upper airway obstruction, bronchospasm, and regurgitation/aspiration-nor on the corresponding requirement for active clinical interventions in real-time practice, which remains a conspicuous and clinically relevant knowledge gap. This gap is further compounded by the observation that even the limited number of prospective studies concentrating on the adult extubation period have reported widely variable complication spectra and employed inconsistent definitions across different institutions, underscoring the pressing need for standardised, multicentre or single-centre prospective data that can inform robust quality benchmarks and facilitate meaningful comparisons across settings. Concurrently, a growing body of literature has raised legitimate concerns regarding the heightened perioperative risk associated with off-hours and on-call working conditions, wherein the convergence of increased workload due to concurrent emergency cases, diminished availability of senior supervisory staff, and the progressive accumulation of clinician fatigue and sleep deprivation may collectively predispose to suboptimal clinical performance and adverse patient outcomes; indeed, while off-hours surgery has been associated with higher mortality relative to daytime procedures, the existing evidence remains of low certainty, and patient-specific as well as surgical characteristics do not fully account for this observed association, thereby necessitating further investigations that specifically target human and organisational factors as explanatory variables. Within this context, the objective and validated assessment of clinician fatigue becomes particularly pertinent, and the Karolinska Sleepiness Scale (KSS), which has been widely employed in anaesthesia research, verified against electroencephalographic (EEG) measurements, and previously utilised to evaluate sleepiness levels under on-call conditions, offers a practical and psychometrically sound tool to objectively quantify the impact of fatigue on airway management performance during extubation. Motivated by these converging imperatives, this prospective observational cohort study at Kocaeli City Hospital is designed to compare the incidence of acute airway and respiratory complications, along with the associated intervention requirements, at the moment of extubation and during the immediate 30-minute post-extubation period, between extubations performed during on-hours (08:00-16:00) and those conducted during off-hours (after 16:00, as well as weekends and public holidays), with the overarching aims of strengthening institutional patient safety practices, driving evidence-based process improvements, and ultimately contributing to the broader discourse on perioperative airway safety. Notably, this investigation carries a distinctive scientific value, as it will be the first prospective observational study specifically designed to test NAP7's off-hours risk hypothesis at the extubation stage, thereby directly addressing a critical evidence gap in the current anaesthesia literature and offering actionable insights that may inform future guidelines and organisational policies regarding safe extubation practices across different times of the day.

• Study Type: Observational
• Enrollment (Estimated): 2640

Contacts and Locations

• Study Contact: Name: Mehmet Yilmaz, Md; Phone Number: 05052174432; Email: drmyilmaz33@gmail.com
• Study Contact Backup: Name: Ali Mete Temel, Md; Phone Number: +905438465215; Email: metetemel60@hotmail.com

Study Locations

• Turkey (Türkiye)
  • Izmıt
    • Kocaeli, Izmıt, Turkey (Türkiye), 41001
      • Recruiting
      • Kocaeli City Hospital
      • Contact: Mehmet Yilmaz, Md; Phone Number: 05052174432; Email: drmyilmaz33@gmail.com
      • Sub-Investigator: Mehmet Yilmaz, Md
      • Contact: Ali Mete Temel, Md; Phone Number: +905438465215; Email: metetemel60@hotmail.com
      • Principal Investigator: Ali Mete Temel, Md

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

The study population comprises adult patients (aged ≥ 18 years, with no upper age limit) undergoing either elective or emergency surgery under general anaesthesia with endotracheal intubation at Kocaeli City Hospital, a tertiary referral centre in Turkey. Eligible participants are those in whom tracheal extubation is planned in the operating theatre or in the post-anaesthesia care unit (PACU). The population includes both American Society of Anesthesiologists (ASA) Class I-V patients, reflecting the full spectrum of surgical acuity and comorbidity burden encountered in routine clinical practice. Patients undergoing regional anaesthesia or sedation without intubation, those with a pre-existing tracheostomy, patients transferred intubated to the intensive care unit postoperatively, and those undergoing cardiothoracic surgery involving cardiopulmonary bypass are excluded. Additionally, patients requiring emergency airway management outside the operating theatre, those with a known or susp

Description

Inclusion Criteria:

- Age ≥ 18 years

Undergoing elective or emergency surgery under general anaesthesia with endotracheal intubation

Planned tracheal extubation in the operating theatre or post-anaesthesia care unit (PACU)

Provision of written informed consent (or deferred consent for emergency cases, in accordance with national regulations)

Exclusion Criteria:

• Patients undergoing surgery under regional anaesthesia or sedation without endotracheal intubation

Patients with a tracheostomy in situ

Patients who remain intubated and are transferred to the intensive care unit (ICU) postoperatively

Patients undergoing cardiothoracic surgery involving cardiopulmonary bypass

Emergency airway management performed outside the operating theatre (e.g., ICU, emergency department)

Patients with known or suspected difficult airway requiring awake fibreoptic intubation

Patients who refuse to provide informed consent or withdraw consent during the study

Pregnant patients

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
On-Hours; On-hours group: Extubations performed between 08:00 and 16:00 on weekdays (Monday to Friday), excluding public holidays.	Procedure: Extubation; An extubation attempt is the planned, deliberate removal of the endotracheal tube from the patient's trachea, beginning with preparatory manoeuvres (such as oropharyngeal suctioning and cuff deflation) and ending with the complete withdrawal of the tube and establishment of a patent native airway with adequate spontaneous breathing.; Other: Survey/Questionnaire Administration; Description: The Karolinska Sleepiness Scale (KSS), a validated 9-point Likert scale (1 = extremely alert, 9 = very sleepy, fighting sleep), will be administered to the attending anaesthetist responsible for performing the extubation immediately prior to the extubation procedure. This assessment is performed to objectively quantify the clinician's subjective level of sleepiness and fatigue at the time of extubation. The KSS score will be recorded as a predictor/exposure variable to evaluate the association between anaesthetist fatigue and the occurrence of acute airway and respiratory complications during extubation. This assessment is applied uniformly across both study groups (on-hours and off-hours extubations).
Off-Hours; Off-hours group: Extubations performed after 16:00 on weekdays, as well as all extubations performed on weekends and public holidays, regardless of the time of day	Procedure: Extubation; An extubation attempt is the planned, deliberate removal of the endotracheal tube from the patient's trachea, beginning with preparatory manoeuvres (such as oropharyngeal suctioning and cuff deflation) and ending with the complete withdrawal of the tube and establishment of a patent native airway with adequate spontaneous breathing.; Other: Survey/Questionnaire Administration; Description: The Karolinska Sleepiness Scale (KSS), a validated 9-point Likert scale (1 = extremely alert, 9 = very sleepy, fighting sleep), will be administered to the attending anaesthetist responsible for performing the extubation immediately prior to the extubation procedure. This assessment is performed to objectively quantify the clinician's subjective level of sleepiness and fatigue at the time of extubation. The KSS score will be recorded as a predictor/exposure variable to evaluate the association between anaesthetist fatigue and the occurrence of acute airway and respiratory complications during extubation. This assessment is applied uniformly across both study groups (on-hours and off-hours extubations).

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Incidence of Desaturation During Extubation	Description: The occurrence of desaturation during the extubation procedure itself, defined as a peripheral oxygen saturation (SpO₂) < 90% lasting for ≥ 30 seconds (or a ≥ 5% decrease from baseline in patients with pre-existing hypoxaemia), measured from the initiation of extubation manoeuvres (cuff deflation and suctioning) until the complete withdrawal of the endotracheal tube. Time Frame: Desaturation occurring during the extubation attempt and within the first 30 minutes post-extubation.	30 min. after extubation

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Other acute airway/respiratory complications	(laryngospasm, airway obstruction, bronchospasm, aspiration, apnoea, haemodynamic instability, arrhythmias, unplanned reintubation, surgical airway).	30 min. after extubation

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Intervention requirement by type	(simple airway manoeuvres, bag-mask ventilation, pharmacological agents, reintubation, surgical airway)	30 min. after extubation

Collaborators and Investigators

• Sponsor: Kocaeli City Hospital
• Investigators: Study Chair: Mehmet Yilmaz, Kocaeli City Hospital

Publications and helpful links

General Publications

• Xie Q, Shen Z, Pan M, Li Y, Luo Z, Wang C, Zhao L, Fang Y, Ding X, Teng J, Xu J. Weekend effect on the incidence and outcomes of cardiac surgery associated - acute kidney injury. BMC Cardiovasc Disord. 2023 Oct 27;23(1):524. doi: 10.1186/s12872-023-03431-4.
• Patel MS, Thomas JJ, Aguayo X, Gutmann D, Sarwary SH, Wain M. The Effect of Weekend Surgery on Outcomes of Emergency Laparotomy: Experience at a High Volume District General Hospital. Cureus. 2022 Mar 27;14(3):e23537. doi: 10.7759/cureus.23537. eCollection 2022 Mar.
• Ash-Rafzadeh H, Chambers TJ, Velez FO, Moodie CC, Garrett JR, Fontaine JP, Toloza EM. Effect of Surgical Day of Week on Postoperative Outcomes After Robotic-Assisted Pulmonary Lobectomy. Cureus. 2023 Feb 23;15(2):e35379. doi: 10.7759/cureus.35379. eCollection 2023 Feb.
• Maman D, Steinfeld Y, Berkovich Y. No Weekend Effect in Elective Primary Total Knee Arthroplasty: A Nationwide Analysis of 437,121 U.S. Cases. J Clin Med. 2025 Dec 12;14(24):8816. doi: 10.3390/jcm14248816.
• Cortegiani A, Gregoretti C, Neto AS, Hemmes SNT, Ball L, Canet J, Hiesmayr M, Hollmann MW, Mills GH, Melo MFV, Putensen C, Schmid W, Severgnini P, Wrigge H, Gama de Abreu M, Schultz MJ, Pelosi P; LAS VEGAS Investigators, the PROVE Network, and the Clinical Trial Network of the European Society of Anaesthesiology. Association between night-time surgery and occurrence of intraoperative adverse events and postoperative pulmonary complications. Br J Anaesth. 2019 Mar;122(3):361-369. doi: 10.1016/j.bja.2018.10.063. Epub 2019 Feb 8.

Study record dates

Study Major Dates

• Study Start (Estimated): August 3, 2026
• Primary Completion (Estimated): May 3, 2027
• Study Completion (Estimated): May 15, 2027

Study Registration Dates

• First Submitted: August 3, 2026
• First Submitted That Met QC Criteria: August 3, 2026
• First Posted (Actual): August 7, 2026

Study Record Updates

• Last Update Posted (Actual): August 18, 2026
• Last Update Submitted That Met QC Criteria: August 15, 2026
• Last Verified: August 1, 2026

More Information

Terms related to this study

• Keywords: General anaesthesia; Extubation; Prospective cohort study; Airway complications; Off-hours
• Additional Relevant MeSH Terms: Health Care Quality, Access, and Evaluation; Investigative Techniques; Epidemiologic Methods; Therapeutics; Data Collection; Health Care Evaluation Mechanisms; Quality of Health Care; Public Health; Environment and Public Health; Airway Management; Surveys and Questionnaires; Airway Extubation
• Other Study ID Numbers: KSH-2026-89

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Study data are the exclusive property of Kocaeli City Hospital and may only be shared with formal institutional authorization.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No