Causes Of Pacemaker Infections And Their Countermeasures

Objectives:By a description of infectious symptoms and the analyses of their causes, this dissertation attempts to explore how to prevent and cure cardiac pacemaker infections and provide some scientific instructions for using pacemakers.Methods:Successive surveys were conducted from June,1996to September,2011in First Affiliated Hospital of Kunming Medical University. The research involves1829patients (1247males and582females, aged2-95,64.59±14.49in average) who have received implantation or re-implantation of pacemakers with relatively complete medical records at this hospital. The data show30pacemaker users (23males and7females, aged2-88,61.07±18.90in average) get infected. By focusing on the data of the30infected patients'baseline information, infectious features, therapeutic interventions and curative rehabilitation and by making a comparison with the infected and uninfected ones, this research attempts to find out the causes of inflections, design ways for therapeutic interventions, and evaluate the effects of treatment. For the sake of assessing the optimized countermeasures against pacemaker infections, this study employs SPSS17.0software for data processing and sets P< 0.05as the standard for differences in data analysis.Results:1. Among the1829patients who have received pacemaker implantation or re-implantation,30patients (1.64%) with23males (1.84%) and7females (1.20%), whose ages range from2to88,61.07±18.90in average, get infected. Infections have little to do with sex, male or female (P=0.31). Infected patients below and above60account for12and18respectively, with no significant difference in the infection rate (P=0.98).2. The time of pacemaker infections attack ranges from1week to84months, with a median of3months (14months as a quartile range). In the order of occurrence rate, the number accounts for40%(12cases after1month, but within12months),33%(10cases within1month),27%(8cases after1year) and10(3cases after2years) respectively.3. In the order of infection patterns, the figure accounts for40.0%(12cases for bursa bag abscess, ulcer or necrosis),30.0%(9cases for incision infection),30.0%(9cases for exposure of pacemaker or its wires) respectively. No endocarditis has been found.4. Pacemaker infections have nothing to do with the operation in the same day (P>0.05).5. In the order of the ratio of risk, the pacemaker infections rank as follows: bursa bag hematoma (OR=10.41, p<0.001), reconstructing pacing system at least three times (OR=5.63,p<0.05), complicated diabetes (OR=4.92, p<0.05) dislocation of wires of pacemaker in acute phrase (OR=4.62, p<0.001), more than3hours of operation (OR=4.28, p<0.05), using antibiotics before operation (OR=0.082, p<0.001)6. The secretions from the4infected patients test positive3times (accounting for50%) in the6bacterial cultures:1time for MRSA (methicillin-resistance Staphylococcus aureus),1time for Staphylococcus aureus squirrel staphylococcus double infection, and1time for Salmonella infection.7. The30infected patients undergo69therapeutic interventions in total:20times (30.0%) for restoration of bursa bags after debridement,16times (23.3%) for partial or complete re-implantation of pacemaker,14times (20.3%) for local debridement without cutting bursa bags,9times (13.0%) for lateral or contralateral re-implantation,7times (10.1%) for removing part of the whole wires or pacemaker.8.16reconstructions of pacemakers occurred:3cases (4.3%) for implantation of pacemaker,4cases (5.8%) for electrode-tipped wires,9cases (13.0%) for combined reconstruction,2cases (12.5%) for delayed reconstruction. Only1case (3%) rejects re-implantation after the removal of pacemaker.9Among the30infected patients followed2months at least and338months at most, with a median of46months (96months as a quartile range),29(97%) get healed and pacemakers work.1case (3%) gets restored (p<0.001).Conclusions:1. In the cases of First Affiliated Hospital of Kunming Medical University, the occurrence rate of pacemaker infections is1.64%with no obvious difference between sexes. Infections among the patients above60have little to do with age. More than2/3inflections break out after the operation within1year, and less than1/3cases attack over1year. Therefore, the hardness in finding out the causes of infections requires regular follow-up and timely treatment.2. Many factors contribute to the pacemaker infections. On the basis of susceptibility, they rank as follows:bursa bag hematoma, antibiotics before operation, partial or complete implantation of pacemaker more than once, complicated diabetes, and dislocation of wires of pacemaker. Pacemaker infections have nothing to do with the operation in the same day.3. Nearly all the pacemaker infections belong to local infection. About2/3infections result from bursa bag ulcer, while1/3ones or so account for wires rejection or incision infection. More emphases on instructing patients and more optimized follow-ups help prevent infections and pacemaker works in efficient, safe, economical and convenient ways.4The treatment should adhere to individual treatment principle:local debridement, bursa bag debridement, restoring in depth, lateral partial or whole reconstruction, contralateral partial or whole reconstruction, partial or whole removal of the pacemaker, local or general antibiotics and nutrition supplement. One or more measures help pacemaker work well and97%infections get cured.5Almost1/2pacemaker infections need partial or whole reconstruction treatment. Untimely and incorrect treatment as well as residue of electrode-tipped wires may give rise to pacemaker infections. Thus re-implantation or removal of electrode-tipped wires works in dealing with complicated infections.