The Surgeon and Safety

An Introduction to Safety Theory

and Modeling Applications to

the OR

Overview Why focus on safety in surgery? Acknowledge the surgeon as a part of a

complex human-machine system, the OR Why model the OR and the fundamental

processes of surgery Our IDEF model to define surgery and OR

activities Applications Building the infrastructure for a safer and

more efficient OR

NY Statistics Preventable Medical Injury

Study population where all hospitalize patients in the NY state during the 1984.

30,195 randomly selected patients records from all types of acute care hospitals were reviewed by nurse-abstractors using 18 screening criteria for possible “injury”

7,743 records were reviewed by 2 physicians that were certify either on internal medicine or general surgery.

1,133 patients were identify as having suffer an adverse event.

NY-Patient Injury Findings

3.7 % of all the discharges were marred by an adverse event

28% of adverse events were judged as negligence Over 50% resolved in disability lasting less than a

month. 7% of the disabilities were prolonged of permanent 14% of the patients died as a result of their injuries Adverse events were as twice as common in

patients over 65 year of age Vascular, cardiac and neurosurgical patients have a

significant higher risk of injury than other type of specialty care

70% of adverse events were found to be preventable

24% were judged unpreventable 6% were classified as potentially

preventable

NY-Patient Injury Findings

Today’s Pre-industrial Medicine

Most other industries have employed systems engineering, safety enhancement programs, and quality control methods.

High risk industries such as aviation are remarkably safe. Airlines typically have four billion flights per major accident (hull-loss)

Would you fly on an airline which crashes four times every one hundred take-offs.

Today’s Industrial Age Medicine

What is a System Complex body: a combination of related

elements organized into a complex whole Set of principles: a scheme of ideas or

principles, for example, for classification or for forms of government or religion

Way of proceeding: a method or set of procedures for achieving something

Set of interdependent elements interacting to achieve a common aim. These systems may be both human and nonhuman (equipment, technologies, etc).

[KF] What is System Modeling?

The process of creating a system model.

What is an Engineering Model?

A system model is a formal, symbolic representation of a system in which important system elements, relationships, and behaviors are explicitly represented by structured text, graphical elements and relationships, mathematical equations, or computer software.

[KF] What is a System Model?

A formal, symbolic representation of a system in which important system elements, relationships, and behaviors are explicitly represented by structured text, graphical elements and relationships, mathematical equations, or computer software.

A structure that accurately depicts or mimics the real system.

[KF] Kinds of System Models Structural models represent

Systems & subsystems (humans, machines) Relationships, e.g.,

System/subsystem “Is part of” Information flow Communication

Functional models represent Processes Functions (goal-directed processes) Tasks (functions performed by humans) Procedures (steps to perform functions)

Why do we Model?

To understand To predict To control To design To communicate to our colleagues

in the engineering sciences To realistically train

[KF] Why Model? To understand the system, e.g.,

Help engineers understand the basics. Help medical personnel integrate & get the “big

picture”. To predict, e.g.,

What will happen if we change …? To control, e.g.,

How can we speed up turnaround? To design

Analysis, e.g., Identify human performance issues & opportunities.

Synthesis, e.g., Functional specifications for OR automation.

What is Surgery? Medical procedures involving operations:

medical treatment that involves operations or manipulations on the patient’s body and, usually, cutting the body open to perform these

Branch of medicine: the branch of medicine that deals with diseases and conditions treated by operation or manipulation, or the range of diseases treated in this way

Surgeon’s art or activity: the art or activity of performing surgery

Operating room: a hospital or clinic room where surgery is performed

Surgery Defined as Process Surgery is a process that physically alters

the patient’s anatomy through incision, excision, reconstruction, implantation, etc. in order to diagnosis and treat.

The surgical process transforms the patient’s physiological state to a more advantageous situation (state) for healing, function, cosmesis and the relief of suffering.

PERFORM

SURGERY

Ready PatientOR Ready

Documentation

Surgical GoalPatient Factors

Surgical Sys Factors4 Ps (Philosophy, Policies, Procedures, Practices)

Ready OR Team

Surgeon NursingAnesthetist

Recovering Patient

Finished Documentation

OR to be Cleaned & RestockSurgical Specimens & Waste

[KF] IDEF0 Integrated DEFinition language 0 Ideal for representing processes &

functions Graphical modeling language

Boxes: functions Arrows: relationships

Represents any level of abstraction “Big picture” Fine details

Depicts concurrency, functional dependencies (not sequences)

[KF] IDEF0 Functional Modeling (1) Function

What is the function or process? e.g., “perform laparoscopic hysterectomy”

What systems are transformed (changed) by the function?

e.g., patient, the OR, documents Inputs

What is the state of the systems before the function begins?

Outputs What is the state of each system after the function is

done?

[KF] IDEF0 Functional Modeling (2) Controls

What factors and other things control the function? Guide it? Facilitate it? Impair it?

Mechanisms What actors (humans, machines) perform it?

Subfunctions Should this function be described in more detail so

as to meet the needs of the analysis? If so, what are the subfunctions (simpler processes)

that must be performed to complete it? Repeat this process for each of them.

IDEF0 Conventions

PERFORM

SURGERY

Patient ReadyOR Ready

Documentation

Surgical GoalPatient Factors

Surgical Sys Factors4 Ps (Philosophy, Policies, Procedures, Practices)

Ready OR Team

Recovering Patient

Finished Documentation

OR to be Cleaned & Restock

Inputs: systems and other things that are changed by the function

Function: a goal directed process

Mechanisms: actors (humans or machines) that perform the function

Controls: things that define the goal or/and guide, facilitate, or constrain the function

Outputs: the results of performing the function

Surgical Specimens & Waste

6

restore SurgSys to neutral

state

5

initiate Ptrecovery

A44

perform surgery

3

prepare ORSys for surgery

2

prepare Pt forsurgery

1

plan surgery

surgical specimens

restore 4Ps

rec 4Pssurgery 4PsOR prep4Ps

Pt prep 4Ps

surgical 4 Ps

OR Sys:ready

for prep

Rec Sys: ready for Pt

Pre-op Sys: ready for prep

OR Sys factors Rec Sys factors

clean-up teamrecovery teamOR teamOR Prep teampre-op team

Pre-opSys:used

restoreSurg Sys

goal

Pt recoverygoal

Surg Sysprep goal

Pt prep goal

Pt: ready for prep

surgerygoal

surgical team

documentation: finalized

surgical goal

waste

documentation: initialized

Surg Sys factorsPt factors

OR Sys:used

Pt:closed

OR Sys:ready forsurgery

Pt: readyfor surgery

surgical subgoals

Surg Sys: restored

Surg Sys: ready for prep

Pt: recovering

[KF] Human performance Issues Analysis For each primitive function (i.e., those without subfunctions)

Define the systems and subsystems and their interactions. Identify human performance issues

Physical issues, e.g., Personnel accommodation Accessibility of tools, equipment, controls

Sensory issues, e.g., Visibility Display design

Cognitive issues, e.g., Display/control compatibility Effects of decision biases

Team issues, e.g., Team situational awareness Surgeon/-A communication

Identify opportunities for improving human performance. Changes to equipment Changes to procedures Training

Our Modeling Team

Criticality of failure mode

A procedure in which each potential failure mode is ranked according to the combined influence of severity, detectability, and probability of occurrence.

Detectability

The likelihood that detection methods or current process controls will discover and correct a potential failure mode before a patient is harmed.

Failure mode and effects analysis

A procedure to identify and analyze each potential failure mode in a system to determine

• the possible effects on the process• the severity of each potential failure-

mode• causes of the failure, and• the actions to be taken to repair the

failure

Likelihood of error reaching the patient

The potential for discovery and correction of an error before it reaches a patient.

Failure effect

The consequences(s) a failure mode has on the ensuing steps and the ultimate outcome of the process. The effect is described in terms of what the people involved in the process and/or the patient might experience.

Failure mode

The manner in which a failure is observed; it generally describes the way the failure occurs.

Hazard analysis

The process of collecting and evaluating information on hazards associated with a process to identify significant risks that require implementation of effective control mechanisms.

Probability

The assessment of the likelihood that a particular failure mode will happen.

Root causeAspects of the process or environment that are

the basic reason for failure or that initiate the problem that eventually leads to the failure, such as

• Inadequate procedures• Equipment design defects• Misapplication of information• Lack of knowledge or skills• Wrong methods• Short staffing, or• Ergonomic issues

Severity

The consequences of a failure as a result of a particular filure mode. Severity considers the worst potential consequence of a failure determined by the degree of patient injury that could ultimately occur.

Strategies

Actions intended to lower the reisk of failure mode occurrence. If no action is recommended, the decision not to act is noted.

FAILURE MODE AND EFFECTS ANALYSIS

Prospective risk analysis - involves close examination of high-risk processes to identify needed improvements that will reduce the chance of unintended adverse events.

RISK ASSESSMENT PROCESS

Used in other industries (ie, aviation and manufacturing) to evaluate system safety. Health care organizations now are using it to evaluate and improve the safety of patient care activities.

THE FMEA PROCESS

Promotes systematic thinking about the safety of patient care processes ( ie, what could go wrong, what needs to be done to prevent failures.)

ACCIDENTS

Accidents in the health care setting may be inevitable, but their frequency can be decreased with a dedicated focus on patient safety.

RISK REDUCTION

Risk reduction naturally flows from a positive approach to risk containment and control.

HUMAN ERROR

Although it may be human nature to make mistakes, it also is human nature to create solutions, identify alternatives, and meet future challenges.

PATIENT SAFETY

It is easier for people to do the right thing when a process is made more consistent by standardizing the steps.