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Sunil K Ohri

Publications and source records attributed to Sunil K Ohri.

11 recordsLinked to original sources
PubMed2006

Gastrointestinal dysfunction following cardiac surgery.

Cardiac surgery is associated with a low incidence of GI complications, but with a disproportionate mortality. A number of risk factors have become established which identify patients at risk. CPB is associated with profound reductions in mucosal blood flow. Mesenteric perfusion is altered by primary endothelial dysfunction, which may further be exacerbated by the use of vasoconstrictors during CPB; inflammatory mediators can 'prime' the mesenteric vasculature. Cardiac surgery with or without CPB is associated with increased tissue oxygen demands, particularly by the splanchnic bed. The disparity in general and regional oxygen supply and demand results in the development of mucosal hypoxia and this cannot be attributed to CPB alone. This injury is measurable by reductions in both absorptive and barrier functions of the gut. Protection may be conferred by modulating the perfusion protocol during bypass and pharmacological interventions which modify the inflammatory response to surgery.

Cardiac Surgical Procedures↗
PubMed2005

Effects of pre-natal and early post-natal undernutrition on adult internal thoracic artery function.

OBJECTIVE: Previous studies in humans and animals have suggested that undernutrition in utero and in early post-natal life may lead to altered vascular function in a number of peripheral arteries. We investigated the effect of pre- and post-natal nutrient restriction on the vascular reactivity of the left internal thoracic artery using a sheep model. METHODS: Welsh mountain ewes were mated and assigned to three dietary groups: (1) 100% of total nutritional requirements (control, n=6); (2) 50% of total nutritional requirements during the first 31 days of gestation (n=6); and (3) 50% nutritional restriction during the first 31 days of gestation, followed by a restriction in the diet of their offspring 12-25 weeks post-natally, designed to produce a 15% reduction in growth trajectory (n=7). The male offspring were sacrificed at 130 weeks; the left internal thoracic artery was mounted onto a wire myograph and the reactivity of the vessel to various agonists measured. RESULTS: The offspring of animals who underwent an early gestation nutrient restriction had a significantly increased basal tone (0.41+/-0.25 vs 6.34+/-1.35, p=0.015) and sensitivity to phenylephrine (log EC(50): -6.23+/-0.04 M vs -5.74+/-0.17 M, p=0.036) as compared with control animals. However, this phenomenon was not seen in animals that underwent both pre- and post-natal nutrient restriction. CONCLUSIONS: Pre-natal undernutrition increases the basal tone and sensitivity of the left internal thoracic artery to phenylephrine. This effect is significantly attenuated by continued undernutrition in early post-natal life. These experiments suggest that in utero and early post-natal undernutrition may be important determinants of graft function in later life.

Animal Nutritional Physiological Phenomena↗
PubMed2005

Fetal origins of coronary heart disease-implications for cardiothoracic surgery?

Over the last 15 years, there has been growing evidence that poor nutrition during gestation plays an important role in the development of coronary heart disease. This hypothesis, commonly known as the 'fetal origins of adult disease' has now gained widespread acceptance in the scientific community. In this review, we discuss the evidence for this theory and analyse the patho-physiological mechanisms underlying the relationship between altered fetal growth and coronary heart disease. Finally, the potential relevance of the theory to cardiac surgical practice will be evaluated.

Adult↗
PubMed2004

A prospective randomized study to evaluate stress response during beating-heart and conventional coronary revascularization.

BACKGROUND: Cardiopulmonary bypass (CPB) is associated with a systemic stress hormonal response, which can lead to changes in hemodynamics and organ perfusion. We examined perioperative stress hormone release in low-risk patients undergoing coronary artery bypass grafting with and without cardiopulmonary bypass. METHODS: Fifty-two patients undergoing primary coronary artery bypass grafting by the same surgeon were randomly assigned into either on-pump (n = 26) or off-pump (n = 26) groups. The on-pump coronary artery bypass grafting group underwent mildly hypothermic (35 degrees C) pulsatile cardiopulmonary bypass with arterial line filtration. Arterial blood samples were collected preoperatively, at the end of operation, and at 1, 6, and 24 hours postoperatively. Plasma levels of vasopressin and cortisol were measured using radioimmunoassay. Anesthetic management was standardized. RESULTS: Both groups had similar demographic makeup and extent of revascularization (on-pump coronary artery bypass grafting, 2.8 +/- 1.0 grafts versus off-pump coronary artery bypass grafting, 2.4 +/- 0.9 grafts; p = 0.20). No mortality or major morbidity was observed and there were no crossovers. The cardiopulmonary bypass and aortic cross-clamp times in the on-pump coronary artery bypass grafting group were 63 +/- 24 and 33 +/- 11 minutes, respectively. In both groups there was a similar and significant rise in cortisol and vasopressin levels in the early postoperative phase, with a partial recovery toward baseline values observed at 24 hours postoperatively. Repeated measures analysis of covariance showed no significant difference between the groups with time for both hormones (cortisol, p = 0.40; vasopressin, p = 0.30). CONCLUSIONS: Despite the avoidance of cardiopulmonary bypass, off-pump coronary artery bypass grafting surgery triggers a systemic stress hormone response that is comparable to conventional surgical revascularization. The neurohormonal environment during beating-heart surgery should be further explored.

Aged↗
PubMed2003

Right pleuropericardial release: a useful technique in off-pump coronary surgery.

We describe the use of right pleurotomy combined with right pericardial release during off-pump coronary surgery. The maneuver releases the compression exerted on the right cardiac chambers during cardiac verticalization and improves hemodynamic stability during exposure of the posterior or lateral coronary vessels.

Coronary Artery Bypass↗
PubMed2002

Leukodepletion reduces renal injury in coronary revascularization: a prospective randomized study.

BACKGROUND: Cardiopulmonary bypass (CPB) is an important contributor to renal failure, which is a well-recognized complication after coronary artery bypass grafting (CABG). Leukodepletion reduces CPB-associated inflammation and resultant end-organ injuries. However, its effectiveness in renal protection has not been evaluated in a prospective randomized clinical setting. METHODS: Forty low-risk patients awaiting elective CABG with normal preoperative cardiac and renal function were prospectively randomized into those undergoing nonpulsatile CPB without (group A: n = 20) and with leukodepletion (group B: n = 20). Renal glomerular and tubular injury were assessed by urinary excretion of microalbumin and retinol binding protein (RBP) indexed to creatinine (Cr), respectively. Daily measurements were taken from admission to postoperative day 5. Fluid balance, serum creatinine, and blood urea were also monitored. RESULTS: No mortality or renal complication occurred. Both groups had similar demographic makeups, Parsonnet scores, extents of coronary revascularization and, durations of CPB and aortic cross-clamping. Daily fluid balance, serum creatinine, and blood urea remained comparable in both groups throughout the study period. From equal preoperative values, a significantly higher release of urinary RBP:Cr (7,807 +/- 2,227 vs 3,942 +/- 2,528; p < 0.001) and urinary microalbumin:Cr (59.4 +/- 38.0 vs 4.7 +/- 6.7; p < 0.0001) occurred in group A, peaking on day 1 before returning to approximate baseline levels. CONCLUSIONS: Although clinically overt renal complications were absent, sensitive indicators revealed significantly more injury to both renal tubules and glomeruli after nonpulsatile CPB without leukodepletion. These data suggest that leukocytes play an important role in post-CPB renal dysfunction, and leukodepletion may offer some renal protection in low-risk patients during CABG.

Aged↗
PubMed2002

Mitral valve surgery for acute papillary muscle rupture following myocardial infarction.

BACKGROUND AND AIM OF THE STUDY: Acute papillary muscle rupture (PMR) is a rare but fatal complication of myocardial infarction (MI). Surgery represents the best treatment option, but carries a high risk. Our experience of emergency mitral valve surgery in patients with acute PMR following MI during the past 22 years is reviewed. METHODS: Between 1978 and 2000, 33 patients (20 males, 13 females; mean age 64 years; range: 46-80) underwent emergency surgery for acute post-infarct PMR in our institution. The site of MI was anterior in three patients and inferior in 30. Preoperatively, 17 patients had an intra-aortic balloon pump (IABP) inserted, 26 were on inotropic support, and 17 were ventilated. Twenty patients (61%) underwent concomitant coronary bypass grafting (CABG). The valve was replaced in 31 patients and repaired in two. Mean (+/- SD) duration of follow up was 63+/-54 months (range: 0-183 months). RESULTS: Early mortality (in-hospital) was 21% (n = 7). Factors associated with significant risk of early mortality included raised preoperative serum creatinine (p = 0.02), need for preoperative inotropic support (p = 0.03) and preoperative ventilation (p = 0.03). Raised preoperative serum creatinine remained significant on multiple logistic regression (p = 0.04). Postoperatively, 21 patients required an IABP. Mean duration of intensive care unit stay was 4+/-2.5 days (range: 0-10 days). Survival, including in-hospital mortality, at one, five and 10 years was 75+/-7.4, 65+/-8.6 and 32+/-9.7%, respectively. Four patients required valve-related reoperation (three for a paraprosthetic leak, one for failed repair). CONCLUSION: Patients with acute post-infarct PMR present in a severely compromised state. Early mortality is high, but the intermediate outcome is encouraging for operative survivors.

Aged↗
PubMed2002

Risk of reoperation for structural failure of aortic and mitral tissue valves.

BACKGROUND AND AIM OF THE STUDY: The study aim was to assess the risk of reoperation for patients with a failing stented tissue valve. METHODS: Between 1980 and 1999, 259 patients (118 males, 141 females; mean age 60.1+/-15.4 years) underwent redo valve replacement to replace a failing stented tissue valve. Of these patients, 94 (36.3%) underwent redo aortic valve replacement (AVR), 105 (40.5%) redo mitral valve replacement (MVR), and 60 (23.2%) redo aortic and mitral valve replacement (DVR). Twenty patients (7.7%) had previous coronary artery bypass grafting (CABG); further CABG were performed in 32 cases (12.4%). Preoperatively, 216 patients (83.3%) were in NYHA functional class III or IV. RESULTS: The early mortality was (6.5%; n = 17), including three patients who had AVR, five DVR, and nine MVR. A higher preoperative NHYA status (p <0.0004) and emergency surgery (p <0.0001) were significantly associated with an increased risk of operative death (univariate analysis). Age at surgery (p = 0.45), previous CABG (p = 0.45), position of the valve replaced (p = 0.2), type of implant (p = 0.06) and presence of coronary artery disease (p = 0.51) were not associated with a significant risk of operative mortality. Including those patients who died, 88 (34.0%) experienced a peri- or postoperative complication, seven of which (2.7%) were permanent. CONCLUSION: A failing tissue valve can be replaced, with acceptable operative mortality and morbidity. The choice of valve is a balance of its advantages and disadvantages, and these must be discussed with the patient. It appears, however, that the trend towards reducing the age at which tissue valve implantation is performed may be justified.

Adult↗