Randomized clinical trial of Appendicitis Inflammatory Response score-based management of patients with suspected appendicitis

BACKGROUND

The role of imaging in the diagnosis of appendicitis is controversial. This prospective interventional study and nested randomized trial analysed the impact of implementing a risk stratification algorithm based on the Appendicitis Inflammatory Response (AIR) score, and compared routine imaging with selective imaging after clinical reassessment.

METHOD

Patients presenting with suspicion of appendicitis between September 2009 and January 2012 from age 10 years were included at 21 emergency surgical centres and from age 5 years at three university paediatric centres. Registration of clinical characteristics, treatments and outcomes started during the baseline period. The AIR score-based algorithm was implemented during the intervention period. Intermediate-risk patients were randomized to routine imaging or selective imaging after clinical reassessment.

RESULTS

The baseline period included 1152 patients, and the intervention period 2639, of whom 1068 intermediate-risk patients were randomized. In low-risk patients, use of the AIR score-based algorithm resulted in less imaging (19·2 versus 34·5 per cent; P < 0·001), fewer admissions (29·5 versus 42·8 per cent; P < 0·001), and fewer negative explorations (1·6 versus 3·2 per cent; P = 0·030) and operations for non-perforated appendicitis (6·8 versus 9·7 per cent; P = 0·034). Intermediate-risk patients randomized to the imaging and observation groups had the same proportion of negative appendicectomies (6·4 versus 6·7 per cent respectively; P = 0·884), number of admissions, number of perforations and length of hospital stay, but routine imaging was associated with an increased proportion of patients treated for appendicitis (53·4 versus 46·3 per cent; P = 0·020).

CONCLUSION

AIR score-based risk classification can safely reduce the use of diagnostic imaging and hospital admissions in patients with suspicion of appendicitis. Registration number: NCT00971438 ( http://www.clinicaltrials.gov).

Does training in a virtual reality simulator improve surgical performance?

BACKGROUND

The development of computerized surgical simulators in a virtual reality environment demands models for proper validation. Recent investigations have shown that a virtual reality simulator (MIST-VR) is a reliable tool for the assessment of laparoscopic psychomotor skills and that it improves the automation of the so-called fulcrum effect. Therefore, we set out to determine whether training with the MIST-VR would improve the surgical performance of surgically inexperienced medical students and to see if results obtained in the simulator would correlate with surgical performance.

METHODS

A total of 29 medical students were randomized into two groups. One group received preoperative MIST-VR training. Both groups then performed a simulated laparoscopic appendectomy in a pig. The operations were videotaped and examined by three independent observers.

RESULTS

There was no significant difference in performance between the two groups. The performance with the MIST-VR correlated with the results in surgery.

CONCLUSION

A method that can measure surgical skill, based on the scoring of independent observers who view videotaped performances, seems to be reliable. MIST-VR did not improve the surgical skills of the subjects, but the results with MIST-VR did predict surgical outcome.

Mechanical small-bowel obstruction after conventional appendectomy in children

During the period May 1988 to August 1990, 871 children aged between 0 and 15 years were appendectomized by laparotomy because of suspected appendicitis at the department of pediatric surgery, St. Göran's Children's Hospital. The children were followed 4-6 years after appendectomy. 1.3 % (10/791) developed clinical symptoms consistent with mechanical small bowel obstruction (SBO) resulting in relaparotomy and confirmation of the diagnosis. The patients were divided into subgroups according to the degree of appendicitis. In the group with normal appendix 1.8% (3/170) developed mechanical SBO, simple appendicitis 0% (0/209), gangrenous appendicitis 0.4 % (1/236) and perforated appendicitis 3.4% (6/176). There was no mortality due to postoperative complications. Two patients died due to unrelated causes during the follow-up period.

Prophylactic antibiotics in uncomplicated appendicitis during childhood--a prospective randomised study

544 children operated upon for uncomplicated appendicitis were randomised into three groups. Group I received no antibiotics, patients in Group II were administered one single pre-operative dose of metronidazole (10 mg/kg) and patients in Group III received both both metronidazole (20 mg/kg) and cefuroxime (50 mg/kg) in a single preoperative dose. The rate of infectious complications in Group I was 6.3% but only 2.1 and 2.3 in Groups II and III, respectively. Among patients with a normal appendix or patients with simple appendicitis there was no difference in the rate of post-operative infections between the three different groups. However, in patients with gangrenous appendicitis the rate of postoperative infections was significantly lower in the two groups who received preoperative antibiotics (1.8% and 3.0% respectively) than in the group receiving no prophylactic antibiotics (infection rate 14%). It is concluded that a single preoperative dose of metronidazole significantly decreases the rate of postoperative infectious complications in children with appendicitis. No further improvement could be demonstrated if cefuroxime against aerobic organisms was added.