Incidence and predictors of infection in patients undergoing primary isolated coronary artery bypass grafting: a report from a tertiary care hospital in a developing country.

AIM: Infection following coronary artery bypass grafting (CABG) is a leading cause of morbidity, mortality, and increased length of hospital stay. Many studies have investigated the predictive value of known risk factors for infection in patients following CABG and conclusions have been variable and may reveal regional or institution-specific influence. The purpose of this prospective study was to determine the pre- and peri-operative risk factors for infection in patients undergoing coronary artery bypass surgery in a developing country. METHODS: A prospective study was undertaken to collect data on 12 reported risk factors for all patients undergoing CABG during a five-year period at The Aga Khan University Hospital, Pakistan. The relationship of these risk factors to infection following CABG was evaluated. RESULTS: Out of 767 consecutive patients admitted for CABG, a total of 73 (9.51%) developed 92 infections following surgery. Sternal Surgical Site Infection (SSI) developed in 30 patients (3.91%), of which 29 (96.7%) were superficial and 1 (3.33%) was deep. There were 37 leg wound infections at the site of conduit harvest, and 2 cases of infection at the intra-aortic balloon pump. There were 12 cases of sepsis and 11 urinary tract infections. There were 26 cases (35.6%) of leukocytosis and 17 patients (23.3%) showed elevated erythrocyte sedimentation rate (ESR). Staphylococcus aureus was the most frequently isolated pathogen (39.7%). Bacteremia data was not collected. Of the total cases of infection following CABG, 59 required prolonged hospitalization or readmission. Univariate analysis was performed using a p-value of <0.2 as the inclusion criteria for further analysis using logistic regression. Multivariate analysis with adjusted Relative Risk (RR) showed that diabetes (P=0.002, RR=2.3, 95% CI=1.4-4.0), obesity (P=0.036, RR=2.2, 95% CI=1.0-4.4), use of an intra-aortic balloon pump (P=0.001, RR=3.6, 95% CI=1.7-7.7), female gender (P=0.004, RR=2.5, 95% CI=0.2-0.8) and prolonged mechanical ventilation (P=<0.0001, RR=6.7, 95% CI=2.8-15.5) were independent predictors of infection in the study population. CONCLUSION: This study suggests that diabetes, obesity, use of an intra-aortic balloon pump and female gender are independent predictors of infection in patients undergoing CABG. Early and strict diabetic control and pre-operative weight reduction may reduce the incidence of infection following CABG. Contamination of these patients may occur before, during and after the operation and efforts to curb such contamination must be intensive. Further prospective studies need to be undertaken to identify and establish these and other risk factors for infection in the region and elsewhere.

Catching and killing of airborne SARS-CoV-2 to control spread of COVID-19 by a heated air disinfection system.

Airborne transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) via air-conditioning systems poses a significant threat for the continued escalation of the current coronavirus disease (COVID-19) pandemic. Considering that SARS-CoV-2 cannot tolerate temperatures above 70 °C, here we designed and fabricated efficient filters based on heated nickel (Ni) foam to catch and kill SARS-CoV-2. Virus test results revealed that 99.8% of the aerosolized SARS-CoV-2 was caught and killed by a single pass through a novel Ni-foam-based filter when heated up to 200 °C. In addition, the same filter was also used to catch and kill 99.9% of Bacillus anthracis, an airborne spore. This study paves the way for preventing transmission of SARS-CoV-2 and other highly infectious airborne agents in closed environments.

Is use of temporary pacing wires following coronary bypass surgery really necessary?

AIM: Temporary epicardial pacing wires (TEPW) which are routinely used after coronary bypass grafting may result in significant complications. We sought to identify variables that predict TEPW implantation and thereby limit their use. METHODS: This prospective study enrolled 564 patients (296 underwent coronary artery bypass grafting with cardiopulmonary bypass [ONCAB] and 268 underwent off-pump coronary artery bypass grafting, OPCAB). TEPW were placed in patients with the intraoperative presence of one or more of the following criteria: sinus bradycardia, sinus arrest, nodal/junctional rhythms, atrioventricular block, bundle branch block, ventricular tachycardia, or onset of atrial fibrillation. RESULTS: Only 31 (5.5%) patients [ONCAB: 20 (6.8%) (ventricular: 14, bichamber: 6); OPCAB: 11 (4.1%) (ventricular: 9, bichamber: 2)] had temporary epicardial pacing wires implanted intraoperatively. Indications for using temporary epicardial pacing wires for ONCAB were sinus bradycardia (8), nodal/junctional rhythms (3), atrioventricular block (3), atrial fibrillation (4), and bundle branch block (2), and for OPCAB were sinus bradycardia (8), nodal/junctional rhythms (2), and atrioventricular block (1). Mean duration for pacing was 22.4 h for the ONCAB group and 11.3 h for the OPCAB group. There were no temporary epicardial pacing wires associated complications. One paced OPCAB patient required a permanent pacemaker and 2 non-paced OPCAB patients required transvenous pacing wires. Univariate and multivariate analyses were also conducted to determine risk factors for TEPW. CONCLUSION: TEPW implantation is overused in cardiac surgery and by identifying independent predictors for pacing we conclude that TEPW use should be limited to a select few.

Post-coronary artery bypass surgery pericardial abscess: Salmonella paratyphi B.

Endemic enteric fever is one of the major health problems in South Asia where focal pyogenic infections with salmonella are being increasingly reported. A pericardial abscess following coronary artery bypass surgery with Salmonella paratyphi B was successfully treated, the first reported case so far.

Behind the counter: pharmacies and dispensing patterns of pharmacy attendants in Karachi.

BACKGROUND: There is little literature available on dispensing patterns and unsupervised sale of medicines from pharmacies in developing countries. OBJECTIVE: This study obtained background information on pharmacies, assessed the level of training, knowledge and dispensing patterns of pharmacy attendants in Karachi. METHODOLOGY: This is a descriptive cross sectional study with convenient sampling. A structured questionnaire was used to interview pharmacy attendants. RESULTS: Of the 219 pharmacies surveyed, 62% reported more than 50 customers daily and 20% also sold items of general provision. Mean operating hours were 13. Only 24 (11%) had a visible license. On an average 3 attendants were employed per pharmacy. We interviewed one in each. Amongst the 219 interviewed, 77 (35%) were intermediate qualified and only 26 (12%) pharmacologically trained. Correct frequency of ORS administration was not known by 167 (76%) and 21% incorrectly suggested an anti-diarrhoeal preparation for viral diarrhoea in children. The knowledge of those with pharmacological training was significantly better. For respiratory tract infection in children approximately 60% did not know the correct dose of Paracetamol and Amoxicillin. Only 13 (6%) knew that Propanalol was contraindicated in hypertensive asthamatics. For Cotrimoxazole, metronidazole and lomotil only 40%, 21% and 15% respectively, were aware that these could not be dispensed without prescription. CONCLUSION: In the absence of trained pharmacists existing pharmacy attendants should be trained to improve drug-dispensing patterns.