INADEQUATE POSTOPERATIVE PAIN CONTROL IN AMBULATORY SURGERY

Budapest 7 de Mayo de 2013

A. Jiménez, J.A. Gracia, E. Redondo, B. Calvo, B. Jiménez, M. Martínez.

  

BACKGROUND.

Ambulatory surgery constitutes near 50% of all surgery performed in Spain nowadays. Postoperative pain control is one of the most important objectives in this surgery in order to reach patient satisfaction and to avoid unplanned hospital admissions. Recent studies have shown that large numbers of patients suffer from moderate to severe pain during the first 24-48 hours (Rawal N. 2007).

 

 

 

 

 

 

 

This bad postoperative pain control forces to consult with general practitioner, causes adverse physiological effects (respiratory, cardiovascular, gastrointestinal, urinary and metabolic) and involves hospital admissions. These undesirable consequences induce the increase of costs associated with ambulatory surgery.

 

 

 

 

 

 

 

The Day Surgery Unit (DSU) of U.H. Lozano Blesa in Zaragoza, Spain, began its activity in 1995 as a multidisciplinary unit and in the last two years almost 3000 patients/year were operated on in the DSU. Protocols of postoperative pain control were improved in year 2000 after noticing a poor pain control in some patients.

OBJECTIVE.

 

 

 

 

 

 

This study was undertaken to examine the success or failure in the postoperative pain control in our multidisciplinary DSU and its relation to the different types of surgery.

METHODS.

The unit is integrated in a University General Hospital with independent facilities. A total of 24035 patients were scheduled to be operated on in the DSU from March 1995 to November 2012. The surgical specialties included were Ophthalmology (45.9 per cent of patients), General Surgery (19.8 per cent), Orthopedic Surgery (13.4 per cent), Urology (7.2%), Vascular Surgery (6.1 per cent), ENT (4.9 per cent) and Gynecology (2 per cent).

 

 

 

 

 

 

Patients and their caregivers were instructed in pain control using oral drugs as metamizol (dipyrone, non-opioid analgesic) or paracetamol (acetaminophen, NSAID analgesic) complemented sometimes with diclofenac (NSAID analgesic), every six or eight hours during the first 3-7 days after surgery, according to the expected pain, mild, moderate or severe.

 

 

 

 

 

 

 

Recovery events in the postanesthetic care unit and at home after discharge were registered in a database during the first 30 days of postoperative period. Statistical analyses were performed using Stat-View 5.1.0 software. Statistical comparisons were made with ANOVA test and t test according to qualitative or quantitative variables. Significance was defined as p<0 .05.="" o:p="">

 

RESULTS.

 

 

 

 

 

 

 

 

Among the 487 patients (2.1 per cent) with bad postoperative pain control (289 women, 198 men), median age was 55 years with a symmetrical distribution. However patients between 41 and 65 years old suffered significantly more pain than older (3.2 per cent and 1.2 per cent respectively) and than younger (2.3 per cent).

 

 

 

 

 

 

 

 

 

ASA status I patients had a significant higher incidence of pain than ASA status II or III patients (2.5 per cent, 2 per cent and 1.5 per cent respectively). These findings can be related to the different types of surgery as we will show later.

 

 

 

 

 

 

 

The most common types of anesthesia were local combined with sedation (31 per cent), retrobulbar block (29 per cent), spinal (22 per cent) and general anesthesia (12 per cent). Patients having spinal anesthesia and axillary plexus technique had significant higher incidence of bad postoperative pain control (4.5 per cent and 3.9 per cent) than local and retrobulbar block (1 per cent and 1.2 per cent).

 

 

 

 

 

 

 

 

The mean duration of surgery was 34 min (median 30 min) but the patients who had bad postoperative pain relief had longer duration (43 min) probably related to a more complex procedure and an increased tissue trauma.

 

 

 

 

 

 

 

The type of surgery is probably the factor that has most influenced the poor control of postoperative pain. As in the majority of studies orthopedic patients suffered most painful surgery (5.9 per cent) while ophthalmological and ENT patients (1.1 and 1 per cent) had the best postoperative pain relief. Vascular surgery and general surgery patients also suffered postoperative pain above the mean (3.3 per cent and 2.5 per cent). Analysing each type of surgery, the majority of published studies recognize that shoulder surgery has the greatest incidence of severe postoperative pain but we have a very short experience with this surgery in ambulatory basis.

 

 

 

 

 

 

 

Our study shows that hallux valgus correction with 8.5 per cent of patients suffering poor postoperative pain control is the most painful surgery followed by knee arthroscopy (6.7 per cent), hernia repair (3.4 per cent), varicose vein surgery (3.3 per cent) and anal surgery (2.5 per cent). On the other hand the cataract surgery was the less painful (1 per cent) followed by laryngeal microsurgery (1.3 per cent) and testicle surgery (1.4 per cent).

All these significant predictive factors are interrelated being the age and the type of surgery the most important probably. To probe this  we should have conducted a multivariable analysis. The body mass index is also an important factor in other studies but this index is not registered in our database.   

 

 

 

 

 

 

Among the 487 patients with poor postoperative pain control,  39  of them (8 per cent) needed immediate hospital admission and 4 were admitted after discharge. Our DSU has a mean of 2 per cent of unexpected hospital admission by different causes and of this small percentage, 0.13 is due to a poor postoperative pain control.

CONCLUSIONS.

1. Adequate pain control is important to avoid patient dissatisfaction, adverse physiological effects and unplanned hospital admissions.

2. Principally hallux valgus correction and knee arthroscopy, but also hernia repair surgery, varicose vein stripping and anal surgery are the procedures more frequently related to bad postoperative pain control.

3. In patients with risk factors as the type of surgery and anesthesia, the longer duration of some interventions, the age between 40 and 65 years of patients and even the ASA status I it’s necessary to develop more effective strategies for control of postoperative pain.

REFERENCES.

-F. Chung ete al. Postoperative pain in ambulatory surgery. Anesth Analg 1997; 85:808-16.

-F. Coluzzi et al. Determinants of patient satisfaction in postoperative pain management following hand ambulatory day-surgery. Minerva Med 2011; 102(3):177.86.

-O. L. Elvir-Lazo and P. F. White, PhD. Postoperative Pain Management After Ambulatory Surgery: Role of Multimodal Analgesia. Anesthesiology Clin 2010;28: 217–224.

-S. Mukherji and A. Rudra . Postoperative pain relief for ambulatory surgery. Indian J. Anesthes. 2006; 50(5):355-362.

-N. Rawal. Postoperative pain treatment for ambulatory surgery. Best Pract Res Clin Anaesthesiol 2007;21(1):129-48.