The Resuscitation Predictor Scoring Scale RPS Scale for inhospital cardiac arrests

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The Resuscitation Predictor Scoring Scale (RPS
Scale) for in-hospital cardiac arrests

• Dr Simon Cooper (PhD)
• Senior Lecturer (FHSW)
• Chris Evans (BSc) Research Assistant.
• Statistical verification from Dr Steve Shaw,
  University of Plymouth.

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Derriford Hospital, Plymouth. 1,200 beds.
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Objectives of the Study

• To identify the key factors influencing survival
  in CPR attempts.
• To quantify CPR survival rates 15 minutes into a
  resuscitation.

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Patients and Methods

• A seven year study (1993-2000) of 2,567
  in-hospital emergency calls.
• Excluded for this study were
• False alarms (14).
• Respiratory arrest only (3).
• Patients lt20 years (2).
• Multiple arrests (18).
• Leaving 1,633 patients who received full CPR.

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Results Survival Rates

• Immediate survival - 661 (41).
• 24 hour survival - 444 (28).
• Discharge survival 297 (19).

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Results Key Predictors of Survival to 24 hours
(from regression analysis)

• Duration of resuscitation - majority of survivors
  resuscitated within 15 minutes.
• Primary arrhythmia - survival more likely for
  patients in VT/VF.
• Patients age - those lt70 years significantly more
  likely to survive.
• Primary mode of arrest (respiratory or cardiac) -
  survival more likely where the mode of arrest was
  respiratory.
• All significant at Plt0.001

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The RPS Scale Whos it for?
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How was the RPS Scale developed?

• Stage 1.
• The weighting scores (from the regression) were
  allocated to each variable.
• Which provided an individual total score for
  each case.

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Development of the RPS Scale(Ranking
combinations)
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Development of the RPS Scale

• Stage 2
• Selected patients who were resuscitated for gt15
  minutes (N 741).
• Compared predicted survival status with actual
  survival, to establish reliability of the
  predictors.
• (Reliability of the 4 predictors 90. See
  comment in Conclusion)

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Development of the RPS Scale

• Stage 3
• Calculated the actual survival rates for each
  combination of variables to provide Table A/B on
  RPS Scale.

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The Final RPS Scale Prerequisites

• For in-hospital use.
• 15 minutes into a resuscitation.
• Where there has been no return of spontaneous
  circulation during the resuscitation attempt.
• With consideration of additional factors listed
  in Table C.

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The RPS Scale Table AUse this table 15 minutes
into a resuscitation where the following
variables are known.
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The RPS Scale Table BUse this table 15 minutes
into a resuscitation where the following
variables are known.
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The RPS Scale Table C (Additional key
predictors of survival reducing survival).

• Resuscitation Factors
• Delay (gt3 minutes) to commencement of BLS.
• No return of spontaneous circulation during
  resuscitation.
• Pre Arrest Morbidity
• Malignancy especially metastatic.
• Homebound lifestyle.
• Sepsis (on admission).
• Pneumonia (on admission).
• Creatinine gt220 mmol/l.
• Hypotension (systolic lt 90mmHg).
• Glasgow Coma Scale 3-5.

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Conclusions

• The predictors are validated by many previous
  studies (e.g BRESUS).
• The scale has good face validity.
• The variables listed have a predictive accuracy
  of greater than 90.
• The survival rates listed are exact for this
  population.
• The population is a representative microcosm.

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ANY QUESTIONS?