In this section :

Selected Serious Events: Introduction

​Overview and Implications

Selected Serious Events and select Never Events in Canada

Patients expect safe care, and healthcare providers strive to deliver care that results in better health and safe, effective outcomes for patients. However, events that harm patients do occur while care is being provided, or as a result of that care. While risk is an inherent part of care, we know that many of these events that cause harm can be prevented using current knowledge and practices. Many of these events occur only rarely, but all can have a severe impact on the lives and well-being of patients. Health Quality Ontario (HQO), and the Canadian Patient Safety Institute (CPSI) partnered with several jurisdictions and organizations in Canada to create a list of 15 Never Events (NE). Never Events are patient safety incidents that result in serious patient harm or death and that are preventable using organizational checks and balances (HQO & CPSI, 2015).

The selected serious events included in this resource are:

  • Failure of sterile precautions during surgical and medical care during:
    • surgical operation*
    • infusion or transfusion
    • kidney dialysis or other perfusion
    • injection or immunization
    • endoscopic examination
    • heart catheterization
    • aspiration, puncture, and other catheterization
  • Contaminated medical or biological substances
  • Failure in suture or ligature during surgical operation
  • Endotracheal tube wrongly placed during anesthetic procedure
  • Performance of inappropriate operation*

* Correspond with Never Events #1 and #4: NE #1 surgery on the wrong body part or the wrong patient or conducting the wrong procedure. NE #4 patient death or serious harm arising from the use of improperly sterilized instruments or equipment provided by the healthcare facility.

Failure of sterile precautions

The purpose of maintaining sterile precautions is to reduce the number of microbes present to as few as possible. The sterile field is used in many situations outside the operating room as well as inside the operating room when performing surgical cases. Sterile fields should be used outside the operating room when performing any procedure that could introduce microbes into a patient. A few examples of this would be inserting a foley catheter, an arterial line, and a central line. Inside the operating room, sterile fields are created relative to the back table, the mayo stand, and finally the patient and the surgical site itself (Tennant, 2021). Failure of sterile precautions during medical and surgical procedures has resulted in the spread of infection and disease transmission. This has led to increased morbidity and mortality for patients as well as increased length of stay and increased costs (Siegel, Rhinehart, Chiarello et al., 2007, Ontario Agency for Health Protection and Promotion, 2013). 

Aseptic, Sterile, and clean techniques

Historically, the practice of protecting patients from contamination and infection during clinical procedures has generated an inaccurate and confusing paradigm based on the terminology of sterile, aseptic, and clean techniques. The use of accurate terminology is important in order to promote clarity in practice (National Health and Medical Research Council - NHMRC, 2019). The Australian Guidelines for the Prevention and Control of Infection in Healthcare (NHMRC, 2019) offers the following definitions:

Sterile 'Free from microorganisms' Due to the natural multitude of organisms in the atmosphere it is not possible to achieve a sterile technique in a typical healthcare setting. Near sterile techniques can only be achieved in controlled environments such as a laminar air flow cabinet or a specially equipped theatre. The commonly used term, 'sterile technique' (i.e., the instruction to maintain sterility of equipment exposed to air), is obviously not possible and is often applied inaccurately.

Asepsis 'Freedom from infection or infectious (pathogenic) material' An aseptic technique aims to prevent pathogenic organisms, in sufficient quantity to cause infection, from being introduced to susceptible sites by hands, surfaces and equipment. Therefore, unlike sterile techniques, aseptic techniques are possible and can be achieved in typical hospital and community settings.

Clean 'Free from dirt, marks or stains' Although cleaning followed by drying of equipment and surfaces can be very effective it does not necessarily meet the quality standard of asepsis. However, the action of cleaning is an important component in helping render equipment and skin aseptic, especially when there are high levels of contamination that require removal or reduction. To be confident of achieving asepsis an application of a skin or hard surface disinfectant is required either during cleaning or afterwards.

The aim of any aseptic technique is asepsis.

As defined above, aseptic technique is the purposeful prevention of transfer of microorganisms from the patient's body surface to a normally sterile body site or from one person to another by keeping the microbe count to an irreducible minimum. Aseptic techniques are measures designed to render the patient's skin, supplies and surfaces maximally free from microorganisms. Such practices are used when performing procedures that expose the patient's normally sterile sites (e.g., intravascular system, spinal canal, subdural space, urinary tract) in such a manner as to keep them free from microorganisms (NHMRC, 2019; PHAC, 2012).

To practice safely it is essential that healthcare workers understand the principles and practice of aseptic technique. An example of an aseptic technique is Aseptic Non-Touch Technique (ANTT), a comprehensively defined practice framework for aseptic technique developed by the Association for Safe Aseptic Practice (The-ASAP, 2015). 

Sterilizations of medical and surgical instruments and equipment: Infection is a major risk of surgery and despite modern technologies and procedures, infections related to improper equipment reprocessing still occur.

Achieving effective disinfection and sterilization is essential for ensuring that medical and surgical equipment/devices do not transmit infectious pathogens to clients/patients/residents or staff. The goals of safe reprocessing of medical equipment/devices include:

  • preventing transmission of microorganisms to personnel and clients/patients/ residents.
  • minimizing damage to medical equipment/devices from foreign material (e.g., blood, body fluids, saline, and medications) or inappropriate handling (Ontario Agency for Health Protection and Promotion, 2013).

Contaminated medical or biological substances

The tainted blood tragedy is one of the worst public health disasters that Canada has ever faced. When AIDS appeared in the early 1980s and soon became an epidemic, the entire Canadian blood supply system was affected. More than 1,100 transfused Canadians were infected by HIV, of whom 700 had hemophilia and other bleeding disorders, and 400 were transfusion recipients for other reasons (trauma, surgery, childbirth, cancer). Up to 20,000 were infected with the hepatitis C virus (HCV) through blood and blood products before testing was introduced in 1990 (Canadian Hemophilia Society, retrieved April 2021). This tragedy led to the Royal Commission of Inquiry on the Blood System in Canada, led by Justice Horace Krever. In 1997, Justice Krever tabled his report in the House of Commons, putting forward a set of 50 recommendations that, to this day, guide the blood system to ensure safety for all Canadians (Canadian Blood Services-Transfusion, 2019).

The transplantation of a human tissue allograft introduces the risk of complications to the recipient including the fatal and nonfatal transmission of infectious organisms such as bacteria, fungi, viruses, parasites, and prions. Tissue banks are considered to be manufacturers of human biologics where donor tissue is processed and enhanced using good manufacturing practices and good tissue practices to optimize safety and clinical outcomes. As biological manufacturers of tissue allografts that present a risk of disease transmission, tissue bank practices that reduce and eliminate infectious organisms must be effective, evidence-based and validated (Canadian Blood Services- Organs and Tissues, 2016).

Failure in suture or ligature during surgical operation

Most of the knot and suture failures exist due to technical errors in tying and wrong selection of sutures or knots in different scenarios. Common failure modes of knots and sutures are suture breakage, knot loosening, knot breakage, and tissue breakage. Failure of any of these factors can destroy the repair construct (Öçgüder, 2018).

Endotracheal tube wrongly placed during anesthetic procedure

Endotracheal intubation is a routine procedure in anesthetic care. Immediate verification of endotracheal placement of the ETT is necessary as esophageal or endobronchial intubation is a significant source of avoidable anesthetic-related morbidity and mortality (Miller, 2015). Serious complications can occur from inadvertent placement of the endotracheal tube in a main stem bronchus, such as hypoxemia caused by atelectasis formation in the unventilated lung and hyperinflation and barotrauma with development of a pneumothorax of the intubated lung. Proper positioning of the endotracheal tube in relation to the carina is clinically important (Sitzwohl et al, 2010).

Performance of inappropriate operation*

Surgery on the wrong body part or the wrong patient or conducting the wrong procedure: Surgery is one area of healthcare in which preventable medical errors and near misses can occur. Of great concern is wrong-site surgery (WSS), which encompasses surgery performed on the wrong side or site of the body, wrong surgical procedure performed, and surgery performed on the wrong patient. WSS has also been defined as a sentinel event (i.e., an unexpected occurrence involving death or serious physical or psychological injures, or the risk thereof) by the Joint Commission, which found WSS to be the third-highest-ranking event (Mulloy & Huges, 2008).  

Wrong site surgeries have been associated with the failure to identify incorrect information in the documents related to surgery, such as the schedule, consent, and patient's history and physical examination. The opportunities for wrong site surgery are minimized when all the information is in agreement, and when all members of the operating room (OR) team assume a personal responsibility for the procedure (Pennsylvania Patient Safety Authority, 2007). The Pennsylvania Patient Safety Authority study (Yonash, 2020) showed that the frequency of WSS varied according to a range of variables, including error type (e.g., wrong side, wrong site, wrong procedure, wrong patient); year; facility type; hospital bed size; hospital procedure location; procedure; body region; body part; and clinician specialty. Many clinicians, patient safety professionals, and organizations take the position that WSS events are preventable and should never occur (Yonash, 2020).

Distractions and/or interruptions related to human communication, equipment such as surgical alarms or technology (e.g., phone calls, pagers) are a threat to patient safety in the OR as they have been found to contribute to patient safety incidents and have been reported to be linked to wrong-side surgery and wrong-site surgery. Guidelines and tools have been developed by perioperative professional associations and patient safety agencies to limit and/or ameliorate the negative impact of distraction and these include application of the "sterile cockpit" concept from aviation, reducing distractions from technology and noise, use of surgical safety checklists and briefings and teamwork training. Engagement of surgeons and multidisciplinary teams is necessary to address the problem of distractions in the OR (Pennsylvania Patient Safety Authority, 2014).

Unnecessary/obsolete procedure involves the performance of a surgery that was deemed unnecessary given the clinical situation. It may also involve the performance of a procedure or the use of a technique that is no longer considered to be standard. The performance of an unnecessary or an obsolete procedure may be related the failure of monitoring individual surgeon's practices or due to a misinterpretation of diagnostic tests (HIROC, 2016).


Reduce the incidence of serious selected events captured in this clinical group.

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