Estrategias preventivas del síndrome de burnout

INTRODUCTION.

In recent years increasing sophistication in non-invasive investigation and high quality angiography allowing accurate pre­ operative assessm ent of patients with critical limb ischaem ia, coupled with the exp ertise of sp ecialist vascular surgeons attem pting ever more complex distal revascularisation are thought to lead to increased limb salvage and su rvival. Patients referred to a sp ecialist unit with an a g gressive revascularisation policy should have a lower amputation rate and higher survival than patients treated in a non­ sp ecialist vascular un it.

To determine the accuracy of th is view , two groups of patients with critical limb ischaemia were stu d ied . The fir st group of patients were studied in th e Regional Vascular Service (R V S), situated at Charing Cross H ospital, London, W.6. and compared to a group of patients with critical limb ischaemia presenting to a D istrict General Hospital

(DGH), th e Lister General Hospital in Steven age, H ertfordshire. The RVS accepts patients both from within its local catchment area, the R iverside D istrict, servin g a population of 279,000 people and from other d istricts within North West Thames Region. The RVS is staffed by a Professor of Surgery and a Senior Lecturer with Honorary Consultant sta tu s, two Senior Surgical R egistrars with a vascular in terest and a fully equipped Vascular Laboratory.

The d istrict hospital accepts th e majority of its patients from within the d istrict, a population of 180,000. Elective vascular su rgery was performed entirely by one of th e four consultant su rgeon s.

AIM OF THIS STUDY.

This chapter id en tifies the risk factors for critical limb ischaemia in two populations, the fir st are patients referred to the RVS and the second patients referred to the DGH. Logistic regression analysis being performed to id en tify differences in limb salvage and mortality between the two groups.

PATIENTS AND METHODS.

A consecutive series of patients from the RVS and th e DGH with critical limb ischaemia (BeU et al, 1982) were stu d ied . Patients with acute limb ischaemia were excluded, as were patients with proven arterial embolism, B eurger's disease and arterial trauma.

The RVS patients were recruited over a th irty one month period, from 1st January 1989 to 31st July 1991, and the DGH patients over a sixteen month period, from 1st April 1990 to 31st July 1991. AU patients were entered prospectively into the stu d y . A nalysis of the two groups was made by comparing th e demographic populations and their referral pattern s. A ge, sex and th e foUowing risk factors were analysed; diabetes meUitus, hypertension, ischaem ic heart d isease, strok e, renal faUure and smoking sta tu s. The indication for entry into th e stu d y and the referral patterns are also analysed.

The author recruited aU patients presenting to the DGH with symptoms of lower limb ischaemia and th ose fu lfillin g th e criteria for

critical limb ischaemia were entered prosp ectively into th e stu d y . The demographic data for th is group were compared and contrasted with that for th e RVS patien ts.

STATISTICAL ANALYSIS.

Statistical analysis was performed usin g Chi square with Yates correction and Mann-Whitney U te s t. Logistic regression analysis was performed to id en tify risk factors affectin g limb salvage at the RVS compared to the DGH. The Cox Proportional Hazards Model was used to analyse any difference in mortality between the two groups.

RESULTS.

Table 3 .1 lis ts the patient details from the RVS and the DGH. The RVS treated 153 patients with 174 critically ischaemic limbs during 31 months of recruitm ent from 1st January 1989 to 31st July 1991. The DGH treated 30 patients with 30 critically ischaemic limbs during their 16 month period of recruitm ent from 1st April 1990 to 31st July 1991. There were more male than fem ales ( RVS 1.3 to 1, DGH 2 to 1 ) in each group, their median age was 72 and 73 years (inter-qu artile range RVS 61 to 78 years, DGH 68 to 80 y e a r s).

Listed in the table are the prevalence of risk factors for peripheral vascular d isease. Both groups had a similar proportion of patients with diabetes m ellitus (RVS 34%, DGH 30%), hypertension (RVS 54%,

DGH 53%), ischaemic heart disease (RVS 39%, DGH 30%). D ifferences in prevalence occurred in patients with a h istory of stroke (RVS 19%, DGH 4%)and renal faüure (RVS 11%, DGH 4%). L ess than 20% of patients in eith er group had never smoked. Statistical analysis of th e groups showed no statistically sign ifican t difference between the two populations.

L ogistic regression analysis was performed to id en tify risk factors affectin g limb salvage at th e RVS compared to th e DGH. The following independent risk factors were analysed : diabetes m ellitus, hyp erten sion, ischaemic heart d isease, cerebrovascular d isease, renal failu re, smoking sta tu s, Doppler sy sto lic ankle pressure and pressu re index of le ss than 0 .5 . No factor was sign ifican t, the b est predictive factor trend was a pressure index of le ss than 0.5 ( =3.66, p = 0 .0 5 6 ).

Cox Proportional Hazards Model was used to analyse any difference in mortality between the RVS and the DGH, none existed ( = 0 .5 0 , p = 0 .4 8 1 ). But analysis of the risk factors for total mortality for patients at the RVS, using th e same model, adjusted for age and s e x , identified two sign ifican t risk factors: ischaemic heart disease (relative risk 2 .2 0 , 95% confidence interval 1.14 to 4 .2 6 , p = 0.016) and renal impairment (relative risk 2 .7 0 , 95% confidence interval 1.26 to 5 .8 0 , p = 0 .0 1 6 ).

The definition of critical limb ischaemia (B ell et al. 1982) was fulfilled by all patients in both groups (table 3 .2 ). The majority of patients (64% at the RVS and 80% at th e DGH) had ulceration or gangrene to a variable ex ten t. Patients with rest pain alone and a

Doppler ankle sy sto lic pressu re of le s s than 40 mmHg was p resen t in 36% of the group at the RVS and 20% at th e DGH. The median Doppler ankle sy sto lic p ressu re for each patient was 39 mmHg at both the RVS and the DGH. The median ankle to brachial p ressu re index in patients at th e RVS was 0.27 and 0.25 in patients at the DGH.

Referral patterns d iffered , as might be exp ected , between the two hospitals (Table 3 .3 ). As a tertiary referral cen tre th e RVS accepted 15% of referrals from other hospitals and 18% of referrals from other disciplines within Charing C ross Hospital, mainly from the Endocrine and the Nephrology departm ents. All referrals to the DGH came from General Practitioners (GP) (90%) or from th e Care of the Elderly department within the DGH (10%), (x^ = 7 .2 , p = 0 .0 2 7 ). R eferrals to th e RVS came from outside the d istrict in 37% of ca ses, many d irectly from GP's outside the d istrict without access to a local vascular su rgeon. This differed sign ifican tly at the DGH, only one (3%) patient was referred from outside the d istrict (x^ = 11.4, p = 0.007)

TABLE 3 .1 . DEMOGRAPHIC DATA OF PATIENTS WITH CRITICAL