SCI: Pressure Ulcers (2007)

Citation:
 
Study Design:
Class:
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Quality Rating:
Research Purpose:
To evaluate the results of surgical treatment of pressure ulcers in spinal cord injury (SCI) patients and the correlation of the outcome variables with various factors that may adversely affect treatment results.
Inclusion Criteria:

Spinal cord injury patients who underwent surgical treatment for pressure ulcers at a Veterans Hospital in a regional referral spinal cord injury unit between 1992 and 1997 whose medical records were complete and had a minimum follow-up of 12 months.

Exclusion Criteria:
Those SCI patients and their medical records which had returned to their local facilities and communities.
Description of Study Protocol:

Recruitment

SCI patients who underwent surgical treatment for pressure ulcers at a Veterans Hospital in a regional spinal cord injury unit between 1992 and 1997.

Design

  • Retrospective evaluation of 48 patients with a total of 70 pressure ulcers by chart review and follow-up phone interview.
  • Age, gender, spinal cord injury level, ulcer characteristics to include ulcer location and number, grade of severity, and presence of osteomyelitis was collected along with mental status, presence of cardiac or pulmonary disease or diabetes, smoking history and the number of previous procedures for that specific ulcer.
  • Laboratory results included hemoglobin, hematocrit, PT/PTT, albumin, and total protein.
  • Surgery was documented as debridement alone, direct closure, skin graft, random fasciocutaneous flap, or muscle/musculocutaneous flap; and whether the procedure was single stage or an initial debridement followed by delayed closure.
  • Postoperative variables were examined and included type of bed used and duration of surgical drains. 
  • Outcome measures included postoperative complications (seroma, hematoma, wound infection, wound separation, partial or total flap loss, major pulmonary complication, deep venous thrombosis, stroke, and death), ulcer reoccurence or development of a new ulcer at a different site, duration of antibiotic use, length of time until sitting program was instituted, and duration of hospital stay.

Blinding used (if applicable)

Not clear if phone interviewers were blinded 

Intervention (if applicable):  Not applicable 

Statistical Analysis

Co-morbid conditions, nutritional status, smoking history, type of repair performed, type of bed used postoperatively, ulcer location and severity, duration of postoperative antibiotic therapy, time elapsed before sitting rehabilitation began, and length of hospital stay were evaluated against one another using the t-test, the correlation coefficent, and ANOVA followed by pairwise comparison tests.

Data Collection Summary:

Timing of Measurements

 A retrospective evaluation on consecutively treated patients with a minimum follow-up of 12 months was implemented by chart review and follow-up telephone interviews.

Dependent Variables

  • Ulcer repair outcome measures to include postoperative systemic and wound-healing complications, recurrance rates, and the development of new ulcers at different sites.

Independent Variables

  • Co-morbid conditions, nutritional status, smoking history, type of repair performed, type of bed used postoperatively, ulcer location and serverity, duration of postoperative antibiotic therapy, time elapsed before sitting rehabilitation began, and length of hosptial stay. 

Control Variables

  •  none noted
Description of Actual Data Sample:

Initial N: More than 100 underwent surgical treatment for pressure ulcers.  48 had complete hospital records.

Attrition (final N): 48

Age: 54.2, range of 37 - 76 years

Ethnicity: not noted by author

Other relevant demographics: 32 (71.1%) paraplegic, 13(28.9%) quadriplegic.

Anthropometrics Subjects varied by level of spinal cord injury and number of ulcers. Co-morbid conditions were not similar across the subjects.

Location: Veterans Hopsital in a regional referral spinal cord injury unit

 

Summary of Results:

 

Variables

Duration to discharge, weeks

p -Value

Ulcer location

Sacrel

Trochanteric

Ischial

 

15.3 ± 6.4

  8.9 ± 2.0

  8.5 ± 3.7

 

< 0.04

--

--

Wound separation

yes

no

 

17.0 ± 8.6

 9.0 ± 4.4

 

< 0.02

--

New or Recurrent Ulcer

New ulcer

Recurrent ulcer

 

 

 7.8 ± 4.5

12.9 ± 7.3

 

< 0.04

--

 

Other Findings

  • Smokers had longer courses of antibiotic therapy than nonsmokers (40.3 days vs. 26.8 days; p < 0.05).
  • A higher serum total protein was correlated with a shorter duration of antibiotic therapy (p < 0.006).
  • Otherwise, none of the other variables correlated significantly with postoperative complications or with ulcer recurrence.
Author Conclusion:
  • The only outcome variables that showed any correlations were length of hospital stay and duration of antibiotic use. 
  • Ulcer location (in particular sacral ulcers) and development of local wound complications had a negative impact on length of hospital stay, and a longer course of antibiotic treatment was required if total protein was lower or if the pateint was a chronic smoker.
  • No significant correlatins were found between any postoperative systemic or wound complications, ulcer recurrence, or new ulcer development and patient age, level of spinal cord injury, number of ulcers and grade, laboratory values, mental status, cardiac or pulmonary disease, diabetes, and presence or absence of osteomyelitis.
Funding Source:
Government: Dept. of Veteran's Affairs
University/Hospital: Baylor College of Medicine
Reviewer Comments:
  • 32 (71.2%) of the participants were paraplegic, 13 (28.9%) were quadriplegic and the precise level of spinal cord injury was undocumented in 3 patients.  14 of the patients (29.2%) had multiple ulcers.  
  • 18.6% had some cognitive mental status impairment, 91.6% had a history of cardiovascular illness (hypertension under treatment, prior myocardial infarction or coronary bypass, angina pectoris), 80.0% had a history of pulmonary disease, 32.0% had diabetes, and 61.7% were smokers.
  • The distribution of the pressure ulcers was unequal with 42.0% being ischial ulcers.  12 particpants had osteomyelitis, and surgical proceures were not evenly distributed.
  • Postoperative care was may have incurred bias as type of bed [air-fuidized- 72.9%, low-air loss bed, 8.3% and regular beds 18.8%] was not evely distributed among the participants.
Quality Criteria Checklist: Primary Research
Relevance Questions
  1. Would implementing the studied intervention or procedure (if found successful) result in improved outcomes for the patients/clients/population group? (Not Applicable for some epidemiological studies) Yes
  2. Did the authors study an outcome (dependent variable) or topic that the patients/clients/population group would care about? Yes
  3. Is the focus of the intervention or procedure (independent variable) or topic of study a common issue of concern to dieteticspractice? Yes
  4. Is the intervention or procedure feasible? (NA for some epidemiological studies) Yes
 
Validity Questions
1. Was the research question clearly stated? Yes
  1.1. Was (were) the specific intervention(s) or procedure(s) [independent variable(s)] identified? Yes
  1.2. Was (were) the outcome(s) [dependent variable(s)] clearly indicated? Yes
  1.3. Were the target population and setting specified? Yes
2. Was the selection of study subjects/patients free from bias? Yes
  2.1. Were inclusion/exclusion criteria specified (e.g., risk, point in disease progression, diagnostic or prognosis criteria), and with sufficient detail and without omitting criteria critical to the study? Yes
  2.2. Were criteria applied equally to all study groups? Yes
  2.3. Were health, demographics, and other characteristics of subjects described? Yes
  2.4. Were the subjects/patients a representative sample of the relevant population? Yes
3. Were study groups comparable? No
  3.1. Was the method of assigning subjects/patients to groups described and unbiased? (Method of randomization identified if RCT) N/A
  3.2. Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline? No
  3.3. Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.) N/A
  3.4. If cohort study or cross-sectional study, were groups comparable on important confounding factors and/or were preexisting differences accounted for by using appropriate adjustments in statistical analysis? No
  3.5. If case control study, were potential confounding factors comparable for cases and controls? (If case series or trial with subjects serving as own control, this criterion is not applicable.) N/A
  3.6. If diagnostic test, was there an independent blind comparison with an appropriate reference standard (e.g., "gold standard")? N/A
4. Was method of handling withdrawals described? Yes
  4.1. Were follow-up methods described and the same for all groups? Yes
  4.2. Was the number, characteristics of withdrawals (i.e., dropouts, lost to follow up, attrition rate) and/or response rate (cross-sectional studies) described for each group? (Follow up goal for a strong study is 80%.) Yes
  4.3. Were all enrolled subjects/patients (in the original sample) accounted for? Yes
  4.4. Were reasons for withdrawals similar across groups? Yes
  4.5. If diagnostic test, was decision to perform reference test not dependent on results of test under study? N/A
5. Was blinding used to prevent introduction of bias? ???
  5.1. In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate? N/A
  5.2. Were data collectors blinded for outcomes assessment? (If outcome is measured using an objective test, such as a lab value, this criterion is assumed to be met.) ???
  5.3. In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded? ???
  5.4. In case control study, was case definition explicit and case ascertainment not influenced by exposure status? N/A
  5.5. In diagnostic study, were test results blinded to patient history and other test results? N/A
6. Were intervention/therapeutic regimens/exposure factor or procedure and any comparison(s) described in detail? Were interveningfactors described? Yes
  6.1. In RCT or other intervention trial, were protocols described for all regimens studied? N/A
  6.2. In observational study, were interventions, study settings, and clinicians/provider described? Yes
  6.3. Was the intensity and duration of the intervention or exposure factor sufficient to produce a meaningful effect? Yes
  6.4. Was the amount of exposure and, if relevant, subject/patient compliance measured? N/A
  6.5. Were co-interventions (e.g., ancillary treatments, other therapies) described? Yes
  6.6. Were extra or unplanned treatments described? N/A
  6.7. Was the information for 6.4, 6.5, and 6.6 assessed the same way for all groups? Yes
  6.8. In diagnostic study, were details of test administration and replication sufficient? N/A
7. Were outcomes clearly defined and the measurements valid and reliable? Yes
  7.1. Were primary and secondary endpoints described and relevant to the question? Yes
  7.2. Were nutrition measures appropriate to question and outcomes of concern? Yes
  7.3. Was the period of follow-up long enough for important outcome(s) to occur? Yes
  7.4. Were the observations and measurements based on standard, valid, and reliable data collection instruments/tests/procedures? Yes
  7.5. Was the measurement of effect at an appropriate level of precision? Yes
  7.6. Were other factors accounted for (measured) that could affect outcomes? Yes
  7.7. Were the measurements conducted consistently across groups? Yes
8. Was the statistical analysis appropriate for the study design and type of outcome indicators? Yes
  8.1. Were statistical analyses adequately described and the results reported appropriately? Yes
  8.2. Were correct statistical tests used and assumptions of test not violated? Yes
  8.3. Were statistics reported with levels of significance and/or confidence intervals? Yes
  8.4. Was "intent to treat" analysis of outcomes done (and as appropriate, was there an analysis of outcomes for those maximally exposed or a dose-response analysis)? N/A
  8.5. Were adequate adjustments made for effects of confounding factors that might have affected the outcomes (e.g., multivariate analyses)? No
  8.6. Was clinical significance as well as statistical significance reported? Yes
  8.7. If negative findings, was a power calculation reported to address type 2 error? N/A
9. Are conclusions supported by results with biases and limitations taken into consideration? Yes
  9.1. Is there a discussion of findings? Yes
  9.2. Are biases and study limitations identified and discussed? Yes
10. Is bias due to study's funding or sponsorship unlikely? Yes
  10.1. Were sources of funding and investigators' affiliations described? Yes
  10.2. Was the study free from apparent conflict of interest? Yes