Faculty of Health Sciences
Permanent URI for this communityhttp://ir-dev.dut.ac.za/handle/10321/11
Browse
3 results
Search Results
Item Investigation of acute systemic inflammatory response and myocardial injury after cardiac surgery in patients infected with human immunodeficiency virus(2016) Gojo, Mawande Khayalethu Edson; Prakaschandra, RosaleyIntroduction: The immediate post-cardiopulmonary bypass (CPB) immune responses and organ injuries in immune- compromised patients remain poorly documented. We conducted a prospective clinical study to determine whether or not human immunodeficiency virus (HIV) seropositive patients generate higher acute systemic inflammatory response and suffer greater myocardial injury, compared to HIV seronegative patients. Methodology: Sixty-one consecutive patients i.e. Thirty HIV seropositive patients and Thirty-one seronegative, undergoing elective cardiac valve(s) replacement were enrolled, over a period of nine months from a single center hospital, after informed consent was acquired. The C-reactive protein (CRP) and Erythrocyte sedimentation rate (ESR) were used as biomarkers of acute inflammatory response, and cardiac troponin I (cTnI) as a biomarker for measuring postoperative myocardial injury. Single tests were measured preoperatively and postoperatively, in both groups, and these were compared and correlated to perioperative events and CPB parameters. Results: The mean age group was similar between the HIV seropositive and negative group (37.8 and 37.1 years, respectively). Preoperatively both groups had relatively equal CRP levels (p=0.388), ESR levels (p=0.817) and cTnI (p=0.489). The CPB events and durations were significantly different between the two groups, CPB duration (p=0.021). Other CPB events include, clamp aortic duration (p=0.026), CPB blood transfusion (p=0.013), CPB total urine output (p=0.035) and CPB peak lactate (p=0.040). Postoperatively we observed significant increased biomarkers level in both groups, with no significant difference between the groups: mean CRP (p=0.115), mean ESR (p=0.214) and cTnI (p=0.363). We observed a significant negative correlation between the mean change in CRP levels and mechanical ventilation (r=- 0.548, p=0.002) in the seropositive group, but not in the uninfected group (r=0.025, p=0.893). The correlation between the difference in CRP and ICU stay was not significant between in both group (r=-0.231, p=0.229 and r=0.25, p=0.975, respectively). A significant positive correlation between postoperative cTnI and the inotropic support duration (r=0.384, p=0.040) was seen in the seropositive groups, but not in the negative group (r=0.092, p=0.622). Furthermore we observed a significant drop in CD4 cells postoperatively (p=<0.001) in the HIV seropositive group. Antiretroviral treatment appeared to influence the degree of change in CD4 cells postoperatively. Conclusion: We conclude that HIV positive patients’ postoperative reactions to cardiac surgery supported by CPB are similar to those of HIV seronegetive patients. We further report non-paralleling correlations between the biomarkers and perioperative events; however these do not seem to affect the overall outcomes between the two groups.Item Comparative in vitro analysis of a balanced electrolyte solution versus an unbalanced electrolyte solution, for processing of residual pump blood using cell saver for patients undergoing elective cardiac surgery(2016) Pillay, Krishnan; Adam, Jamila Khatoon; Mohapi, M.J.Introduction: A large volume of residual haemodilute blood remains in the cardiopulmonary bypass (CPB) circuit after termination of the bypass. It is common practice in many centres to process residual pump blood with an autologus cell salvage system (ACSS), thereby producing a re-suspended red blood cell (RBC) concentrate and attenuating the need for donor blood RBC concentrate. It has also become standard practice to wash donor pack red blood cells (PRBC) before adding it to neonate cardiopulmonary circuits (Swindell et al., 2007). Manufactures of ACSS recommend 0.9% sodium chloride (NaCl) as a wash solution for processing salvaged blood. Previous studies have demonstrated that washing PRBC with normal saline results in acid-base (Huber et al., 2013) and electrolyte derangements (Varghese et al., 2007). Infusion of normal saline in healthy volunteers also results in significant changes in osmolality (Williams et al., 1999). The use of normal saline as a wash solution in processing residual CPB blood requires investigation. Aims and Objectives: This was a prospective, quantitative in vitro investigation to analyze and compare the quality of residual pump blood post CPB that had been washed with either an unbalanced electrolyte solution (0.9% normal saline) or a balanced electrolyte solution (Balsol®). Both are crystalloid solutions. The primary objective of the present study was to measure and compare the pH, electrolytes, metabolites, osmolality and strong ion difference (SID) of residual pump blood to the pH, electrolytes, metabolites, osmolality and SID of processed cell saver blood, which was washed with either 0.9% normal saline or Balsol® solution. The secondary objective was to measure and compare protein levels (albumin and total protein) in residual pump blood to protein levels in processed cell saver blood, that is washed with either 0.9% normal saline or Balsol® solution. The final objective was to determine the volume, haematocrit and haemoglobin yield post cell saver processing, from the input volume of residual pump blood when washed with either 0.9% normal saline or Balsol® solution. This was the first study of this nature done in the South African population group. Methodology: In this investigation in a series of forty patients (n=40) undergoing elective cardiac surgery with CPB, the first twenty patients were allocated to the NaCl control group (n=20) and the second twenty patients were allocated to the Balsol® interventional group (n=20). The extracorporeal circuit consisted of a standard integral hollow fibre membrane oxygenator and tubing that was primed with 1500-1800 millilitres of balanced crystalloid solution (Balsol®), for both the control group and the interventional group, and addition of 5000 iu heparin. The balanced crystalloid solution (Balsol®) is the approved standard CPB priming solution for all cardiac procedures at Inkosi Albert Luthuli Central Hospital. This setup was used with the Stockert S5 roller pump heart lung machine. The operations were performed as per protocol with standard non-pulsatile CPB and hypothermia was maintained at 28 – 32 ºC (core) and haemodilution (haematocrit 20 % to 30 %). A standard flow rate of 2.4 L/min/m² was used. Cardio protection consisted of either cold Blood Cardioplegia using the Buckberg 4:1 ratio, being four parts blood to one part cardioplegia (with the 35ml of 20 % Dextrose + 1 gram Magnesium Sulphate added per 500ml), or 20ml/kg cold St Thomas II cardioplegia (with addition of 10ml of 8.5% NaHCO3 + 100mg lignocain per litre). Topical cooling was achieved with ice cold 0.9 % saline. Maintenance fluid used during CPB was Balsol® for both the control and the interventional groups. Calcium, potassium and sodium bicarbonate was administered as required during CPB to correct deficits for both groups. Weaning of CPB was performed after re-warming to a rectal temperature of at least 35 ºC for both study groups. Immediately on termination of CPB a blood sample was taken from the sampling manifold of the CPB circuit for pre wash analysis. Residual pump blood was then flushed out with one litre of Balsol® solution for both groups and collected into the Medtronic autolog cell saver reservoir to be processed. In the control study group 0.9% NaCl was used as the wash solution and in the interventional study group Balsol® solution was used as the wash solution. After processing of the salvaged blood is complete, a blood sample was taken for post wash analysis. Clinical data recorded for pre and post wash samples included: pH, pCO2, pO2, [K+], [Na+], [Cl-], [Ca2+], lactate, glucose, [HCO3-], TCO2, haematocrit, haemoglobin (GEM 4000® premier™ blood gas analyser) blood volume (Medtronic autolog) and SID (calculated as per equation). Inorganic phosphate, total magnesium, albumin, total protein (Siemens Advia 1800 blood gas analyser) and osmolality (Gonotech osmometer) were also measured. Results: There was a highly significant decrease (p < 0.05) within the NaCl group after washing with pCO2 (28.3 ± 2.9 vs. <6.0 ± 0.0), [K+] (4.5 ± 0.5 vs. 1.0 ± 0.7), total magnesium (1.7 ± 0.7 vs. 0.29 ± 0), ionized calcium (1.0 ± 0.09 vs. 0.1 ± 0.03), inorganic phosphate (0.9 ± 0.4 vs. 0.09 ± 0.04) and SID (27.1 ± 2.1 vs. 18.4 ± 2.2). There was a highly significant increase (p < 0.05) within the NaCl group after washing with pH (7.5 ± 0.1 vs. 7.7 ± 0.1), [Na+] (132.9 ± 3.2 vs. 146.3 ± 1.9), [Cl-] (107.8 ± 3.1 vs. 127.4 ± 2.1) and osmolaltity (256.9 ± 38.4 vs. 296.2 ± 57.5). There were highly significant decrease (p < 0.05) within the Balsol® group after washing with pCO2 (30.15 ± 6.0 vs. 18.9 ± 4.9), [Na+] (134.7 ± 2.2 vs. 125.6 ± 1), [Cl-] (108.8 ± 2.7 vs. 100.2 ± 1.4), ionized calcium (0.9 ± 0.1 vs. 0.02 ± 0.04), inorganic phosphate (0.8 ± 0.2 vs. 0.1 ± 0.024) and osmolality (288.8 ± 20.6 vs. 272.8 ± 19.9). There were highly significant increase (p < 0.05) within the Balsol® group after washing with pH (7.5 ± 0.1 vs. 7.7 ± 0.1), [K+] (4.2 ± 0.4 vs 4.6 ± 0.3). Total magnesium and SID were similar after washing within the Balsol® group. Albumin and total protein revealed similar significant decreases within both groups after washing. There was a highly significant difference (p < 0.05) in the change between groups after washing in all the variables measured, except for pH, inorganic phosphate, lactate, glucose, albumin, total protein, haematocrit, haemoglobin, and blood volume. Total carbon dioxide and [HCO3-] were not compared because they were incalculable by blood gas analyser in the NaCl group. Conclusion: This investigation concluded that the balanced electrolyte solution Balsol® used for washing residual CPB blood results in a re-suspended RBC concentrate, with an osmolality and electrolyte profile that is superior compared to washing residual CPB blood with 0.9% NaCl solution.Item Venoarterial modified ultrafiltration versus conventional arteriovenous modified ultrafiltration during cardiopulmonary bypass surgery(2009) Mohanlall, Rakesh; Nemlander, Arto; Adam, Jamila KhatoonINTRODUCTION: The role of modified ultrafiltration (MUF) in removing inflammatory mediators, reducing the need for homologous donor blood and decreasing pulmonary vascular resistance after cardiopulmonary bypass (CPB) has already been established. Different types of MUF systems evaluated illustrated that none of the MUF techniques adhered to the normal venous to arterial blood flow dynamics. OBJECTIVES: This experimental study compared a conventional arteriovenous modified ultrafiltration (AVMUF) system to a custom designed venoarterial modified ultrafiltration (VAMUF) system. This technique of VAMUF was designed to mimic the pro-grade flow pattern of the body and cardiopulmonary bypass circuit as compared to the conventional retrograde AVMUF systems. METHODS: Sixty patients that underwent MUF were divided into two groups, the AVMUF (n = 30) and the VAMUF (n=30) groups. Modified ultrafiltration was performed for a mean time of 12 minutes in both groups. In AVMUF blood was removed from the aorta, haemoconcentrated and infused into the right atrium (RA). In VAMUF blood flow was from the RA through a haemoconcentrator and re-infused into the aorta. RESULTS: There was no significant difference in any of the demographic variables, CPB or crossclamping time. Results showed significant difference in the ventilation times, with the VAMUF requiring a shorter ventilation time than the AVMUF group. Intensive care unit (ICU) stay, Hospital stay and discharge days were all significantly lower in the VAMUF group as well. The VAMUF also showed a lower percentage fluid balance than the AVMUF. The systolic and mean blood pressure was significantly higher after VAMUF with a decrease in heart rate, and central venous pressure (CVP). The VAMUF group showed a significantly greater decrease of Creatinine, serum lactacte and uric acid over time with no significant differences in oximetry. CONCLUSION: Results prove that VAMUF is more effective compared to the conventional AVMUF regarding the haemodynamics and clinical parameters of the patient and is more physiological with regards to blood flow dynamics. The VAMUF is, therefore, a more physiological technique than AVMUF.