The 1998 Normal Appendectomy and Perforated Appendicitis Rate in Manila Doctors Hospital

 

 

Reynaldo O. Joson, MD, MHA, MHPEd, MS Surg

Overall Coordinator

 

Members of Task Force on Normal Appendectomy and Perforated Appendicitis Rates*

Drs. R. Aman, L. Bernardo, J. Caraos, T. Catabas, G. Cruz, M. Dalluay, M. de Leon,

A. Dumlao, R. Dy, V. Mag-iba, K. Reubenfeldt, and E. San Luis

 

                                                           

Introduction

           

            In 1998, the Manila Doctors Hospital created a quality assurance committee to improve management of patients with acute nontraumatic right lower quadrant  (RLQ) abdominal pain.

 

            One of the committee’s strategies is to develop an evidence-based clinical practice guideline.

 

            The conceptual framework of the guideline development project is as follows:

 

 

Input

Throughput

Output

           

Variations in diagnostic and treatment  process

      Confused patients

      Confused medical students

 

Costly diagnostic and treatment process

 

Delays in diagnosis and treatment

 

Missed diagnosis

 

Wrong diagnosis

 

Medicolegal suits

 

 

 

 

evidence-based

clinical practice guidelines

 

on

 

acute nontraumatic

right lower quadrant

abdominal pain

Standardized diagnostic process and treatment process

     Well-informed patients

     Well-informed students

 

Cost-effective diagnostic and treatment process

 

Efficient diagnosis and treatment

 

Reduced missed diagnosis

 

Reduced wrong diagnosis

 

Reduced medicolegal suits

 

--------------------------------------

Decreased

  negative appendectomy

  rate to an acceptable

  level

  without significantly          

        increasing

  perforation rate

  and its morbidity and

  mortality consequences

 

 

            All the items listed under the input column are the perceived problems.  The evidence-based clinical practice guideline is the proposed intervention.  The expected output will be an improvement of the problems listed in the input column.

 

            The primary goal of this evidence-based clinical practice guideline is to achieve a better health outcome in terms of reducing the incidence of delayed, missed, and overdiagnosis of acute appendicitis in patients presenting with acute nontraumatic RLQ abdominal pain, thereby, reducing the perforation and negative appendectomy rates to an acceptable level.  

 

            The secondary goal is to promote rational cost-effective diagnostic and treatment processes in the management of patients with acute nontraumatic RLQ abdominal pain,  thereby achieving a high quality care.

 

            All the perceived problems in the input column need documentation to see if they really exist.  If they do, the data gathered will be used as baseline data to be compared with the post intervention data to see if improvement has really occurred with the clinical practice guideline.

           

            Various task forces were created for the documentation of baseline data as well as for the formulation of clinical practice guidelines.  These task forces are working simultaneously and in a concerted cooperative manner.

 

            One task force is assigned to gather statistical data on the normal appendectomy and perforated appendicitis rates. 

 

            This paper is a report of this particular task.

 

 

            General Objective:

                       

                        To gather statistical data on the normal appendectomy and perforated appendicitis rates as part of a quality assurance activity in Manila Doctors Hospital.

 

 

            Specific Objectives:

                       

                        1. To determine and compare the normal appendectomy rate of Manila Doctors Hospital with global rates.

 

                         2. To determine and compare the perforated appendicitis rate of Manila Doctors Hospital with global rates.

 

 

Materials and Methods

 

            The 1998 records of the Operating Room and Surgical Pathology of the Manila Doctors Hospital were reviewed as to normal appendectomy and perforated appendicitis rates.

 

            All operative technique records that contained an appendectomy procedure were reviewed.  Only the operations done with a preoperative diagnosis of acute appendicitis were included in the count.  Incidental appendectomies were excluded.   Those with  “perforated appendicitis” written in the space for postoperative diagnosis were counted as perforated appendicitis.  The review of the operative technique records gave the total number of appendectomy done in 1998 and the proportion of perforated appendicitis.

   

            In the surgical pathology logbook, entries with histopathological studies of vermiform appendices were reviewed.  Those with concomitant histopathological studies of other intraabdominal viscera were considered incidental appendectomies and, therefore, excluded in the count.  A histopathological report of “lymphoid hyperplasia” indicated a normal appendix.  The presence of the words  “perforated” and “gangrenous” indicated a perforated appendix.  The review of the histopathological records gave the proportion of normal appendectomies and  perforated appendicitis for 1998.

 

           

Results

 

            The total number of appendices removed for a suspected acute appendicitis in 1998, as gotten from the operating room records, was 156.  The number of grossly “perforated  appendicitis” was 34 given a proportion of  21.8%.

 

            The total number of appendices operated under the clinical diagnosis of acute appendicitis and submitted for histopathological examination in 1998 was 90 or a histopathological examination rate of 57.7%.    The total number of normal appendices found in the submitted appendices was 13, giving a normal appendectomy rate of 14%.  Of the 77 pathologic appendices, 9 were perforated, giving a perforated appendicitis rate of 12%.

 

 

Discussion

 

            In the quality assurance studies of patients with acute appendicitis, the ultimate focus is on the normal appendectomy and perforated appendicitis rates. Delays in diagnosis and treatment, missed and overdiagnosis, morbidity and mortality rates and others can also be used as parameters.  However, all these will eventually end up in using normal appendectomy and perforated appendicitis rates as the overall parameters of quality health care.  For example, overdiagnosis will lead to a high normal appendectomy rate.  Delays in diagnosis and treatment and missed diagnosis will lead to a high perforated appendicitis rate.  A high perforated appendicitis rate will lead to high morbidity and mortality rates.(1-3).     

           

            Table 1 shows a comparison of  the morbidity and mortality rates among normal appendix, acute appendicitis, and perforated appendicitis in 10,023 appendectomies done over 15 years from 1977 - 1992.

 

 

Table 1. Morbidity and mortality rates among normal appendix, acute appendicitis, and perforated appendicitis.

 

Scenarios after appendectomy

Mortality

Complications

Normal appendix

0.14%

4.60%

Acute appendicitis

0.24%

6.10%

Perforated appendicitis

1.66%

(11x normal)

19.30%

(4x normal)

From: Velanovich V, Satava R. Balancing the normal appendectomy rate with the perforated appendicitis rate: Implications for quality assurance.  Am Surg 1992;58:4,264-269.

 

 

            The normal appendectomy and perforated appendicitis rates worldwide and in large series are shown in Table 2 (3).  The normal appendectomy rate ranges from 13 to 32% while the perforated appendicitis rate ranges from 16 to 25%.

 

 

Table 2. Global normal appendectomy and perforated appendicitis rates.

 

Author

N

Time Frame

% Male

Mean Age (yr)

Normal Rate

Perforating Rate

Babcock

1662

1936-1955

NA

NA

NA

25

Mittlepunkt

1000

1960-1964

67

43

NA

24

Lewis

1000

1963-1973

64

NA

20

21

Siberman

1013

1976-1978

NA

NA

15

19

Pieper

1018

1972-1976

49

22

32

20

Maxwell

844

1985-1987

77

24

13

18

Andersson

3029

1984-1989

49

21

31

16

Hale

4950

1992-1993

64

26

13

24

Hale DA, Molloy M, Pearl RH, Schutt DC, Jaques DP.  Appendectomy:   A contemporary appraisal.  Ann Surg 1997; 225:3, 253-61.

 

 

            For the statistics in Manila Doctors Hospital, different figures were gotten from the operating room and surgical pathology records.  

 

            For the normal appendectomy rate, reliance was placed on the histopathological records.  However, considering that only 57.8% of appendices removed were submitted for histopathological examination, the computed figure of 14% is most likely on the low side. 

 

            For the perforating appendicitis rate, reliance would have to be placed on the operating room records, on those that stated  grossly visible perforation on the appendices.  However, considering that only 57.7% of appendices were submitted for histopathological examination and gangrenous appendicitis were not counted under the perforated appendicitis, the computed figure of 21.8% is most likely on the low side.

 

            It is said that there is an inverse relationship between normal appendectomy rate and perforated appendectomy rate. (3)  Achieving  a low normal appendectomy rate will be accompanied by a high perforated appendicitis rate. Likewise, achieving a low perforated appendicitis rate will be accompanied by a high normal appendectomy rate.  Velanovich and Satava (3) opined that despite efforts to achieve an ideal situation, the perforation rate seemed to level off at approximately 10%.

 

            Colson (4) and Temple(5), however, in their studies, indicated that high negative appendectomy rate are no longer necessary and that indiscriminate appendectomy as an attempt to decrease the perforation rate should not be done. 

 

            Historically, a 10-20% negative appendectomy rate was felt to be acceptable in order to minimize the incidence of perforated appendicitis. This implies that the rate of perforation is related to a delay in diagnosis and/or treatment, and that by accepting a higher negative appendectomy rate one can, in effect, buy a lower perforation rate. However, the rate of perforation, about 20-30%,  has changed very little over the last 50 years, despite best efforts (2).  Past (6) and Recent studies (2, 4,5, 7-8) suggest that the rate of perforation is due more to a delay in presentation than to a delay in treatment. This suggests that the incidence of negative appendectomies can be lowered without compromising the perforation rate.

 

            A negative appendectomy rate can be lowered to as low as 5% without compromising perforation rate with adjunctive diagnostic tests, such as active observation (9-20) and imaging techniques (21-22).

           

 

Conclusion

 

            Although the Manila Doctors Hospital statistics on normal appendectomy and perforated appendicitis rates fall within the global ranges, the authors feel that the rates can still be improved.  Future research should be done on how to improve the negative appendectomy and perforated appendicitis rates to achieve a better quality care for MDH patients with acute appendicitis.

 

 

 

References

 

1. Calder JDF, Gajraj H.  Recent advances in the diagnosis and treatment of acute appendicitis.  Br J Hosp Med 1995;54:129-33.

 

2. Hale DA, Molloy M, Pearl RH, Schutt DC, Jaques DP.  Appendectomy:   A contemporary appraisal.  Ann Surg 1997; 225:3, 253-61.

 

3. Velanovich V, Satava R. Balancing the normal appendectomy rate with the perforated appendicitis rate: Implications for quality assurance. 1992;58:4,264-269.

 

4. Colson M, Dunnington G,  Skinner KA. Appendicitis: High negative appendectomy rates are no longer acceptable.  Am J Surg 1997;174:6, 723-6.

 

5. Temple CL, Huchcroft SA, Temple WJ. The natural history of appendicitis in adults.  A prospective study.  Ann Surg 1995;221:3, 278-81.

 

6. White JJ, Scintillana M, Haller JA. Intensive in-hospital observation. A safe way to decrease unncessary appendectomy.  Am Surg 1975;41:793-98.

 

7. Hale DA, Jaques DP, Molloy M, Pearl RH, Schutt DC, dAvis JC.  Appendectomy.  Improving care through quality improvement.  Arch Surg 1997; 132:2, 153-7.

 

8. Levy RD, Degiannis E, Kantarovsky A, Maberti PM, Wells M, Hatzitheofilou C.  Audit of acute appendicitis in a black South African population.  S Afr J Surg 1997; 35:4, 198-202.

 

9. White JJ, Scintillana M, Haller JA. Intensive in-hospital observation. A safe way to decrease unnecessary appendectomy.  Am Surg 1975;41:793-98.

 

10. Hawthorn IE.  Abdominal pain as a cause of acute admission to hospital.  J R Coll Surg Edinb 1992;37:389-93.

 

11. Roffmann LO, Rasmussen OO. Aids in the diagnosis of acute appendicitis.  Br J Surg 1989; 76:774-9.

 

12. Jones PF. Active observation in the management of acute abdominal pain in childhood.  BMJ 1976;   ii:551-3.

 

13. Macklin CP, Radcliffe GS, Merei JM, Stringer MD.  A prospective evaluation of the modified Alvarado score for acute appendicitis in children.  Ann R Coll Surg Engl 1997; 79:3, 203-5

 

14. Magnant C, Nauta RJ.  Observation versus operation for abdominal pain in the right lower quadrant: roles of the clinical examination and the leukocyte count.  Am J Surg 1986; 151:746.

                                   

15. Thompson HH: Acute observation in acute abdominal pain.  Amer J Surg 1986;152:522.

 

16. Joson RJ. Active observation in the evaluation of patients with possible acute appendicitis.  Philippe J Surg Spec 1990; 45:3, 108-111.

 

17. Graff L, Radford MJ, Werne C.  Probability of appendicitis before and after observation.  Ann Emerg Med 1991; 20:5, 503-7.

 

18. Senbanjo RO. Management of patients with equivocal signs of appendicitis.  J R Coll Surg Edinb 1997; 42:2, 85-8.

 

19. Dolgin SE, Beck AR, Tartter PI.  The risk of perforation when children with possible appendicitis are observed in the hospital.  Surg Gynecol Obstet  1992; 175:4, 320-4.

 

20. Gahukamble DB, Rakas FS.  Hospital observation for right lower quadrant abdominal pain with questionable acute appendicitis in children.  Indian J Pediatr 1990; 57:4, 545-50.

 

21. Orr RK, Porter D, Hartmann D.  Ultrasonography to evaluate adults for appendicitis: decision-making based on meta-analysis and probabilistic reasoning.  Acad Emerg Med 1995;2:7, 644-50.

 

22. Balthazar EJ, Megibow AJ, Siegel SE, Birnhaum BA.  Appendicitis: prospective evaluation with high-resolution CT.  Radiology 1991;180:21-4.

 

 

Acknowledgment:

 

*Members of Task Force on Normal Appendectomy and Perforated Appendicitis Rates

 

            MDH Interns Batch 1998-1999

                        Rowena Aman, MD

                        Luzviminda Bernardo, MD

                        Joselino Caraos, MD

                        Tomas Catabas, MD

                        Gary Cruz, MD

                        Melvin Dalluay, MD

                        Melissa de Leon, MD

                        Ariel Dumlao, MD

                        Renelyn Dy, MD

                        Vivien Mag-iba, MD

                        Karen Reubenfeldt, MD

                        Emil San Luis, MD

 

 

 

 

 

 

 

 

 

 

 

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