Indian Journal of Pharmacy and Pharmacology

2. Materials and Methods

2.1. Study design setting and ethical approval

A prospective cross-sectional observational study was conducted at the Medical Device Monitoring Centre (MDMC) functioning under the Materiovigilance Programme of India at Sri Aurobindo Medical College and Post Graduate Institute, Indore, Madhya Pradesh, India, between September 2022 and February 2023.^[11] The study was designed to generate real-world evidence regarding ventilator-associated adverse events reported during routine clinical practice in critical care settings. The overall methodological workflow adopted for ventilator-associated adverse event evaluation under materiovigilance surveillance is illustrated in Figure 1.

Mechanical ventilators are categorized as high-risk life-support medical devices requiring continuous technical monitoring, periodic calibration, and structured preventive maintenance to ensure optimal therapeutic performance and patient safety.^[12] The increased utilization of ventilators during and following the COVID-19 pandemic further emphasized the importance of systematic surveillance of ventilator-associated adverse events and near-miss incidents within established materiovigilance frameworks.^[13] Accordingly, the present study aimed to evaluate the frequency, pattern, severity classification, and technical characteristics of ventilator-associated adverse events in a tertiary healthcare institution.

Data collection was performed throughout the study period, followed by verification, compilation, and descriptive statistical analysis. The study was conducted in accordance with the ethical principles of the World Medical Association Declaration of Helsinki and complied with institutional ethical guidelines for biomedical and medical device-related research.^[14] Confidentiality of patient identity and device-related information was strictly maintained during all phases of the study. Ethical approval was obtained from the Institutional Ethics Committee of Sri Aurobindo Medical College and Post Graduate Institute, Indore (Approval No. SAIMS/EIC/34/22).

2.2. Data source and case identification

Data were collected from Medical Device Adverse Event (MDAE) reporting forms submitted to the Indian Pharmacopoeia Commission through the institutional Medical Device Monitoring Centre established under the Materiovigilance Programme of India. Adverse event reports were voluntarily submitted by healthcare professionals including physicians, nurses, respiratory therapists, and biomedical engineers involved in ventilator management and intensive care practice.^[15]

All reported ventilator-associated adverse events and near-miss incidents documented during the study period were screened for eligibility after verification of completeness, clinical relevance, and technical validity. Reports containing adequate information regarding device characteristics, event description, maintenance status, calibration history, and technical malfunction patterns were included in the study analysis. Incomplete reports, duplicate entries, reports lacking essential technical information, and adverse events unrelated to mechanical ventilators were excluded from the final evaluation.

Relevant demographic, clinical, maintenance-related, and technical variables were extracted from the reporting forms using a structured data collection approach. Extracted parameters included patient demographic characteristics, ventilator-associated technical abnormalities, severity classification, calibration records, preventive maintenance status, duration of device utilization, and intervals between calibration and adverse event occurrence.^[16]

2.3. Classification of adverse events

Reported adverse events were classified according to the guidelines of the Materiovigilance Programme of India based on the nature of the incident, clinical severity, and potential impact on patient safety. Classification was performed using the clinical and technical information documented in the Medical Device Adverse Event (MDAE) reporting forms.^[17] Adverse events were categorized as either near-miss incidents or serious adverse events according to standardized materiovigilance assessment criteria ([Table 1]). Near-miss incidents were defined as ventilator-related technical abnormalities or operational malfunctions with the potential to cause patient harm but identified before resulting in clinically significant consequences. Serious adverse events included incidents associated with death, life-threatening conditions, prolonged hospitalization, permanent impairment, or major medical intervention attributable to device malfunction.^[18] This standardized classification framework ensured consistency, reliability, and uniformity in ventilator-associated adverse event reporting and post-marketing materiovigilance surveillance.

2.4. Assessment of calibration and preventive maintenance status

Calibration status and preventive maintenance history of ventilators associated with adverse event reporting were evaluated using biomedical maintenance records and device documentation available at the institution. Calibration assessment included verification of documented calibration procedures and intervals between the most recent calibration date and occurrence of the reported adverse event. Preventive maintenance evaluation included assessment of scheduled maintenance documentation, servicing records, and biomedical engineering maintenance history associated with the ventilators.^[19] The duration between ventilator installation date and adverse event occurrence was additionally analyzed to evaluate the influence of prolonged device utilization on technical malfunction trends. These maintenance-related assessments were performed to identify potential operational vulnerabilities associated with ventilator safety and performance during routine clinical use.

2.5. Statistical analysis

Collected data were compiled, coded, and analyzed using Microsoft Excel (Microsoft Corporation, Redmond, WA, USA) and Statistical Package for the Social Sciences (SPSS) software version 26.0 (IBM Corp., Armonk, NY, USA). Descriptive statistical methods were used to evaluate demographic characteristics, severity classification, calibration status, preventive maintenance documentation, and technical malfunction patterns associated with ventilator-related adverse events.^[20] Continuous variables, including patient age, duration between ventilator installation and adverse event occurrence, and calibration intervals, were expressed as mean ± standard deviation (SD), whereas categorical variables were summarized using frequencies and percentages. Chi-square test or Fisher’s exact test, where appropriate, was applied to evaluate associations between preventive maintenance status and ventilator-associated technical malfunctions. Spearman’s rank correlation analysis was performed to assess relationships between calibration intervals and technical abnormality frequency. A p-value <0.05 was considered statistically significant.^[21][22]

3. Results

During the study period, a total of 120 medical device adverse event reports were received at the Medical Device Monitoring Centre (MDMC), among which 27 (22.5%) were associated with mechanical ventilators under materiovigilance surveillance. Ventilator-associated adverse events represented a considerable proportion of total reported device-related incidents, emphasizing the clinical relevance of continuous ventilator safety monitoring and post-marketing surveillance in critical care settings ([Figure 2]).

3.1. Demographic characteristics of ventilator associated adverse events

Among the 27 ventilator-associated adverse event reports, 15 (55.5%) involved male patients, whereas 7 (26.0%) were associated with female patients. In 5 (18.5%) reports, no direct patient involvement was documented because the incidents occurred during ventilator testing, calibration procedures, or technical evaluation processes. The mean age of patients associated with ventilator-related adverse events was 49.52 ± 21.42 years ([Table 2]). These findings indicate that ventilator-associated adverse events were predominantly observed among middle-aged and older critically ill patients receiving respiratory support in intensive care settings.

3.2. Severity classification of ventilator associated adverse events

Severity assessment of ventilator-associated adverse events according to Materiovigilance Programme of India (MvPI) classification criteria revealed that all reported incidents were categorized as near-miss events, whereas no serious adverse events were observed during the study period. These findings suggest that the identified ventilator-related technical abnormalities and operational malfunctions were detected before resulting in clinically significant patient harm. The predominance of near-miss incidents reflects the potential role of active materiovigilance surveillance, routine technical evaluation, and timely biomedical intervention in minimizing serious ventilator-associated complications within critical care settings ([Table 3]).

3.3. Calibration and preventive maintenance status of ventilators

Assessment of maintenance-related parameters demonstrated that 23 (85.15%) ventilators associated with adverse event reporting had documented calibration records, whereas 4 (14.81%) devices lacked documented calibration history. In contrast, preventive maintenance documentation was available for only 11 (40.74%) ventilators, while 16 (59.25%) devices had no documented preventive maintenance status ([Figure 3]). Preventive maintenance documentation was substantially lower than calibration documentation, indicating potential deficiencies in routine biomedical maintenance practices. These findings suggest that inadequate preventive maintenance and irregular servicing may contribute to ventilator-associated technical malfunctions and operational deficiencies during routine clinical utilization.

3.4. Time related analysis of ventilator associated adverse events

Time-related analysis demonstrated substantial variability in ventilator utilization duration and calibration intervals among devices associated with adverse event reporting. The mean duration between ventilator installation and occurrence of adverse events was 49.47 ± 47.89 months, indicating prolonged clinical utilization of several ventilators prior to adverse event identification. Similarly, the mean interval between the most recent calibration date and adverse event occurrence was 172.52 ± 123.73 days, reflecting inconsistencies in calibration scheduling and preventive maintenance practices across evaluated devices. Exploratory Spearman’s rank correlation analysis demonstrated a positive association between prolonged calibration intervals and increased frequency of ventilator-associated technical abnormalities (rho = 0.58, p = 0.02), suggesting that delayed calibration practices may contribute to operational instability and reduced ventilator reliability in critical care settings ([Table 4]).

3.5. Distribution of technical problems associated with ventilator adverse events

Technical evaluation of ventilator-associated adverse events demonstrated that low tidal volume was the most frequently reported ventilator-related malfunction, accounting for 11 (40.74%) adverse event reports. Alarm failure represented the second most commonly observed technical abnormality with 4 (14.81%) reports, followed by flow sensor failure in 3 (11.11%) cases. Additional device-related technical problems included low FiO₂ delivery, increased tidal volume alarm abnormalities, sensor and graphical display errors, test failure, oxygen supply interruption, PEEP-related graph errors, device malfunction, check valve failure, and connection errors with patient monitors, each contributing 3.70% of the total reported adverse events. The predominance of ventilatory parameter-related abnormalities and alarm-associated failures highlights the clinical importance of continuous technical monitoring, routine preventive maintenance, and timely calibration practices to minimize ventilator-associated operational deficiencies in critical care settings. These findings further emphasize the critical role of active materiovigilance surveillance in the early identification and management of ventilator-related technical malfunctions before progression to clinically significant patient harm ([Table 5]).

3.6. Association between maintenance deficiencies and ventilator-associated technical malfunctions

Analytical evaluation demonstrated a significant association between deficiencies in preventive maintenance practices and occurrence of ventilator-associated technical malfunctions under materiovigilance surveillance. Chi-square/Fisher’s exact test revealed that ventilators lacking documented preventive maintenance records were more frequently associated with alarm-related abnormalities, ventilatory parameter instability, and sensor-related malfunctions compared with devices having documented maintenance history (p = 0.03). In addition, exploratory Spearman’s rank correlation analysis demonstrated a positive association between prolonged calibration intervals and increased frequency of technical abnormalities (rho = 0.58, p = 0.02), suggesting that delayed calibration practices may contribute to operational instability and reduced ventilator reliability during routine critical care utilization ([Figure 4]). These findings provide clinically relevant real-world evidence supporting the importance of structured preventive maintenance programs, periodic calibration verification, and integrated biomedical engineering surveillance systems for minimizing ventilator-associated technical vulnerabilities. The observed association between maintenance-related deficiencies and technical malfunction patterns further highlights the growing significance of proactive materiovigilance systems in strengthening patient safety, optimizing device performance, and reducing preventable operational risks in intensive care environments (Table 6 and Figure 4).

3.7. Major ventilator safety trends identified under materiovigilance surveillance

Overall analysis demonstrated that ventilator-associated adverse events were predominantly characterized by technical malfunctions and maintenance-related deficiencies. Low tidal volume abnormalities, alarm failure, and flow sensor malfunction represented the major technical vulnerabilities identified during routine clinical practice. Although all reported incidents were classified as near-miss events, deficiencies in preventive maintenance documentation and variability in calibration intervals indicated potential gaps in routine biomedical maintenance systems. These findings emphasize the importance of structured preventive maintenance protocols, standardized calibration practices, and strengthened materiovigilance surveillance systems for improving ventilator safety and operational reliability in critical care environments.

4. Discussion

The present study provides real-world evidence regarding ventilator-associated adverse events reported under materiovigilance surveillance in a tertiary care teaching hospital. Mechanical ventilators are indispensable life-support devices in critical care medicine, and technical malfunctions associated with these systems may compromise respiratory support, oxygen delivery, and patient safety if not identified promptly. The findings of the present study demonstrated that ventilator-associated adverse events were predominantly associated with technical abnormalities, calibration variability, and deficiencies in preventive maintenance practices, emphasizing the importance of structured materiovigilance systems and continuous biomedical surveillance in intensive care settings.

Low tidal volume was identified as the most frequently reported technical abnormality. Inadequate tidal volume delivery may impair ventilation efficiency and contribute to respiratory instability in critically ill patients requiring prolonged ventilatory support. Previous investigations have similarly reported that inaccuracies in ventilatory parameter delivery may adversely affect respiratory outcomes and increase the risk of ventilation-associated complications, including hypoventilation and ventilator-induced lung injury.^[23] The predominance of ventilatory parameter-related abnormalities observed in the present study therefore highlights the importance of continuous ventilator performance monitoring, periodic calibration verification, and timely technical intervention to minimize preventable respiratory compromise.

Alarm failure and flow sensor malfunction were also among the commonly reported technical abnormalities. Alarm systems are essential safety components in modern ventilators because they facilitate early recognition of device malfunction and physiological deterioration. Delayed or failed alarm activation may postpone clinical intervention and increase the likelihood of preventable patient harm. Similarly, flow sensor malfunction may impair respiratory parameter monitoring and ventilator performance assessment.^[24] These findings reinforce the clinical importance of routine technical evaluation and structured biomedical maintenance programs for maintaining ventilator reliability in critical care practice.

An important observation of the present study was that all reported incidents were categorized as near-miss events, while no serious adverse events were identified during the study period. Near-miss reporting plays a critical role in materiovigilance because it enables early identification of latent technical deficiencies and operational vulnerabilities before progression to clinically significant patient injury. Furthermore, the study demonstrated a statistically significant association between preventive maintenance deficiencies and ventilator-associated technical malfunctions. Prolonged calibration intervals were positively associated with increased technical abnormality frequency, suggesting that delayed calibration practices may contribute to reduced ventilator reliability. Overall, the findings highlight the growing importance of active materiovigilance systems, standardized preventive maintenance protocols, and integrated biomedical engineering surveillance for improving ventilator safety and minimizing preventable device-related risks in critical care environments.^[25]

5. Limitations

The present study has certain limitations. Being a single-center observational study with a relatively small sample size, the findings may not be fully generalizable to other healthcare settings. The study relied on voluntarily reported materiovigilance data, making underreporting and reporting bias possible. Detailed evaluation of ventilator manufacturers, device models, ICU-specific distribution, and patient-related clinical factors was not performed. Additionally, the cross-sectional design limited long-term assessment of ventilator performance and causal relationships between maintenance deficiencies and adverse events. Nevertheless, the study provides valuable real-world insights into ventilator-associated technical malfunctions and maintenance-related deficiencies under routine materiovigilance surveillance.

6. Conclusion

The present study provides real-world evidence regarding ventilator-associated adverse events identified under materiovigilance surveillance in a tertiary care teaching hospital. Technical malfunctions, particularly low tidal volume, alarm failure, and flow sensor abnormalities, represented the most frequently reported ventilator-related adverse events in critical care settings. Although all incidents were classified as near-miss events, deficiencies in preventive maintenance practices and variability in calibration intervals indicated potential gaps in routine biomedical maintenance and technical monitoring systems. The findings highlight the clinical importance of structured preventive maintenance, standardized calibration protocols, continuous technical surveillance, and active materiovigilance reporting for improving ventilator safety and operational reliability. Strengthening integrated biomedical engineering and materiovigilance practices may contribute substantially toward reducing preventable device-related risks and enhancing patient safety outcomes in intensive care environments. Future multicentric studies with larger sample sizes and manufacturer-specific evaluations are warranted to strengthen ventilator safety surveillance and biomedical maintenance strategies.

7. Author Contributions

Jitendra Patidar: Data curation, investigation, software. Anuja Jha: Data curation, formal analysis, investigation, resources. Mohammad Nadeem Khan: Data curation, methodology, project administration, validation, writing – review editing. Rashmi Mahajan: Data curation, formal analysis, funding acquisition, investigation, methodology. Pooja Reddy: Investigation, supervision.

8. Source of Funding

None.

9. Conflict of Interest

None.

10. Ethical Approval

The study was approved by Institutional Ethics Committee of Sri Aurobindo Medical College and Post Graduate Institute, Indore (Ref. No. SAIMS/EIC/34/22).

11. Acknowledgment

The authors sincerely acknowledge the Materiovigilance Programme of India (MvPI) and the Indian Pharmacopoeia Commission (IPC), Ghaziabad, India, for their guidance and support in strengthening medical device adverse event reporting and surveillance activities. The authors are also thankful to the Department of Pharmacology and the Medical Device Monitoring Centre (MDMC), Sri Aurobindo Medical College and Post Graduate Institute, Indore, Madhya Pradesh, India, for providing the necessary facilities, technical support, and institutional cooperation for conducting the present study under materiovigilance surveillance.