Table 21 'Postoperative Physiologic Metabolic Derangements'

PSI 20: Postoperative Physiologic Metabolic Derangements
Origin: Review of an AHRQ PSI (3)
Dimension Description
Description of Specific
Aspects of Patient Safety
Postoperative Physiologic Metabolic Derangements is a potentially
life-threatening complication in surgical care. Thus it is a suitable
measure of patient safety.
Aim of the PSI This PSI is intended to flag cases of postoperative metabolic or
physiologic complications.
Level of Determination of
Patient Safety
Safety is assessed at the aggregated patient level.
Source(s) This indicator was originally proposed by Iezzoni et al. as part of the
Complication Screening Programme (CSP 20, “postoperative
physiologic and metabolic derangements”). The University Health
System Consortium adopted the CSP indicator for major surgery
patients (3).
Extent of Clinically
Testing
The project team developing the AHRQ PSI conducted extensive
empirical analyses on this PSI. The team concluded that this PSI
generally performs well on several different dimensions, including
reliability, bias, relatedness of indicators, and persistence over time.
AHRQ panellists had concern about the definition of acute renal
failure: what one doctor may call acute renal failure, another may not.
To ensure that the only renal failure cases that are accounted for are
those that are clinically severe, the panel suggested that acute renal
failure be included only when it is paired with a procedure code for
dialysis. Panellists also noted that coding of relatively transient
metabolic and physiologic complications may be lacking, e.g. cases of
diabetic ketoacidosis. Conversely, some physicians may capture nonclinically
significant events in this indicator. (3).
The AHRQ PSI software was applied to Veteran Affairs (VA)
administrative data to identify potential instances of compromised
patient safety; determine occurrence rates of PSI events in the VA;
and examine the construct validity of the PSIs. The study population
was 97% male, with a mean age of 65 years, 54% were age 65 and
older. All together 11411 PSI events were identified, 46% of PSI
events occurred in surgical hospitalisation and 54% in medical
hospitalisation. The observed PSI rate per 1000 discharges was 1.89
for Postoperative Physiologic Metabolic Derangements. Significant
differences were found for hospitalisations with PSI and those without
PSI events for longer lengths of stay, higher mortality, and higher
costs (4).
The performance of the AHRQ PSIs was analysed to: 1) provide a
descriptive analysis of the incidence of PSI events from 2001 to 2004
in the VA; 2) examine trends in national PSI rates at the hospital
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56
discharge level over time; and 3) assess whether hospital
characteristics (teaching status, number of beds, and degree of quality
improvement implementation) and baseline safety-related hospital
performance predict future hospital safety-related performance. Riskadjusted
rates of the PSI for iatrogenic pneumothorax and failure to
rescue demonstrated no trend in the rate over time. It was concluded,
that this PSI is a useful tools for tracking and monitoring patient safety
events. Future research should investigate whether trends reflect better
or worse care or increased attention to documenting patient safety
events (5).
Administrative data from community hospitals in 16 US states with
reliable race/ethnicity measures using the AHRQ PSIs was analysed to
determine whether racial and ethnic differences in patient safety
events disappear when income (a proxy for socioeconomic status) is
taken into account. Postoperative Physiologic Metabolic
Derangements occur significantly more often among Asian and
Pacific Islander and African American, Non Hispanics than among
white. It was concluded that: ”The AHRQ PSIs are a broad screen for
potential safety events that point to needed improvement in the quality
of care for specific populations” (7).
AHRQ is determining the feasibility and practicality in a project
concerning validation of selected AHRQ Quality Indicators (8).
The results suggest that this PSI may be useful as a measure of patient
safety (3-5;7)
Evidence of Clinically use
of Standards
No evidence of clinically use of standards was found.
PSI category Theme Related PSI: “Surgical Complication”.
Data definitions Cases of specified physiological or metabolic derangement per 1000
elective surgical discharges with an operating room procedure.
Numerator Description Discharges with ICD-9-CM codes for physiologic and metabolic
derangements in any secondary diagnosis field.
Discharges with acute renal failure (subgroup of physiologic and
metabolic derangements) must be accompanied by a procedure code
for dialysis (3995, 5498).
Denominator Description All elective* surgical discharges age 18 and older defined by specific
DRGs and an ICD-9-CM code for an operating room procedure.
*Defined by admit type.
Exclude cases:
− with ICD-9-CM codes for physiologic and metabolic
derangements in the principal diagnosis field
− with a principal ICD-9-CM code for chronic renal failure
− with acute renal failure where a procedure for dialysis occurs
before or on the same day as the first operating room procedure
Note: If day of procedure is not available in the input data file, the
rate may be slightly lower than if the information was available
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− with both a diagnosis code of ketoacidosis, hyperosmolarity, or
other coma (subgroups of physiologic and metabolic derangements
coding) and a principal diagnosis of diabetes
− with both a secondary diagnosis code for acute renal failure
(subgroup of physiologic and metabolic derangements coding) and
a principal diagnosis of acute myocardial infarction, cardiac
arrhythmia, cardiac arrest, shock, hemorrhage, or gastrointestinal
hemorrhage
− MDC 14 (pregnancy, childbirth and the puerperium)
Data Source Administrative data.
Identifying the
institutional context
The impact of postoperative physiologic metabolic derangements
makes this PSI important for both financial and quality improvement
policies.
Care Setting The PSI applies for quality medical care.
Professionals Responsible
for Health Care
Surgeons, anaesthesiologists and nurses.
Lowest Level of Health
Care Delivery Addressed
Individual clinical department.
Allowance for Patient
Factors
Risk adjustment for age, sex and comorbidity categories.
Stratification by
Vulnerable Populations
No stratification.
Standard of Comparison No specific standards given.
Scoring AHRQ has PSI software for scoring.