Peter Raivio

Hydroxyethylstarch and gelatin solutions impair blood coagulation after cardiac surgery: a prospective randomized trial

BACKGROUND Colloids are often used after cardiac surgery as intravascular volume replacement therapy. Cardiac surgical patients have an increased risk of bleeding. Both hydroxyethylstarch (HES) and gelatin solutions impair haemostasis. We examined the impact and dose effect on coagulation of HES 130/0.4, gelatin, or Ringers acetate solutions after cardiac surgery. METHODS Forty-five patients received three boluses (each 7 ml kg(-1)) of either 6% HES 130/0.4, 4% gelatin, or Ringers acetate solution after elective cardiac surgery. The infusion of study solution was continued in the dose 7 ml kg(-1) over the following 12 h. The total dose of study solution was 28 ml kg(-1). Hypovolaemia was treated with Ringers acetate. Modified thromboelastometry was performed to detect coagulation disorders. RESULTS Clot formation time was prolonged and clot strength decreased after infusion of 7, 14, and 21 ml kg(-1) of either colloid compared with the Ringers acetate group. After infusion of 14 and 21 ml kg(-1) of Ringers acetate, clot strength was slightly, but significantly, increased. On the first postoperative morning, clot strength was still decreased in the gelatin group in comparison with the Ringers acetate group. Neither HES nor gelatin induced fibrinolysis. Chest tube drainage was comparable between all groups. CONCLUSIONS Even a small dose of HES 130/0.4 or gelatin impaired clot strength after cardiac surgery in a dose-dependent fashion, but neither colloid increased blood loss.

Pregabalin has an opioid-sparing effect in elderly patients after cardiac surgery: a randomized placebo-controlled trial

BACKGROUND In this prospective, randomized, double-blind, placebo-controlled study, we investigated the effect of pregabalin on oxycodone consumption, postoperative confusion, and pain in elderly cardiac surgery patients. METHODS Seventy patients, aged ≥75 yr, were randomized to receive either 150 mg of pregabalin before operation and 75 mg of pregabalin twice daily for 5 postoperative days or placebo. Pain intensity was measured with the Verbal Rating Scale (VRS). When pain intensity was ≥2 on the VRS, patients received oxycodone either i.v. (0.05 mg kg(-1)) or orally (0.10-0.15 mg kg(-1)). Postoperative confusion was measured with the Confusion Assessment Method for the intensive care unit (CAM-ICU). Postoperative pain was assessed by a telephone interview 1 and 3 months after operation. RESULTS Cumulative consumption of parenteral oxycodone during 16 h after extubation was reduced by 44% and total oxycodone consumption from extubation to the end of the fifth postoperative day was reduced by 48% in the pregabalin group. Time to extubation was 138 min shorter and CAM-ICU scores were significantly lower on the first postoperative day in the placebo group, although there was no significant difference with respect to the Mini-Mental State Examination or the Richmond Agitation Sedation Score. The incidence of pain during movement was significantly lower in the pregabalin group at 3 months postoperative. CONCLUSIONS The administration of pregabalin reduced postoperative opioid consumption after cardiac surgery reduced the incidence of confusion on the first postoperative day and increased time to extubation when compared with placebo. Three months after operation, patients in the pregabalin group experienced less pain during movement.

Comparison of the effect of 6% hydroxyethyl starch and gelatine on cardiac and stroke volume index: a randomized, controlled trial after cardiac surgery

Background and aims: The objective of this study was to find out the effect of various doses of hydroxyethyl starch (HES), gelatine or Ringer’s acetate on cardiac and stroke volume index after cardiac surgery. Material and methods: Three consecutive boluses (each 7 mL·kg-1) of either 6% HES 130/0.4, 4% gelatine, or Ringer’s acetate solutions were administered to 45 patients postoperatively. The rate of infusions was adjusted according to haemodynamic measurements. Thereafter, infusion of the study solution (7 mL·kg-1) was continued for the following 12 hours. The total dose of study solution was 28 mL·kg-1. Results and conclusion: Mean (SD) cardiac and stroke volume indices were greater in the HES group [2.8 L·min-1.m-2 (0.7), 34.1 (6.7) ml·m -2] than in the gelatine group [2.2 L·min-1.m -2 (0.6), 25.8 (7.2) ml·m-2] after completion of 7 mL·kg-1 of study solution. At this stage, the effect of gelatine did not differ from Ringer’s acetate. After completion of 14 mL·kg-1 and 21 mL·kg-1 of colloids, similar cardiac and stroke volume indices were observed and the haemodynamic response was better in both colloid groups than in the Ringer’s acetate group. No differences between groups were detected on the first postoperative morning. In the early postoperative phase after cardiac surgery, the effect of a single dose of HES solution on the haemodynamics was superior to the effect of gelatine or Ringer’s acetate. However, after repeated administration of the study solutions, the haemodynamics in the two colloid groups appeared to be similar, but superior to the Ringer’s acetate group.

The use of balanced HES 130/0.42 during complex cardiac surgery; effect on blood coagulation and fluid balance: a randomized controlled trial.

Introduction: Colloids and crystalloid are used during cardiac surgery for priming of the cardiopulmonary bypass (CPB) circuit. Colloids may decrease postoperative fluid balance because of their high oncotic pressure and low risk of fluid extravasation. On the other hand, colloids have been shown to impair blood coagulation. Materials and methods: In a prospective, randomized, double-blinded study, 50 patients scheduled for coronary artery bypass grafting or a valve procedure were planned to be randomized to receive either balanced 6% HES130/0.42 or Ringer-acetate solution for CPB priming. Randomization was stopped prematurely after 35 randomized patients (19 in the HES and 16 in the Ringer groups) because of the published report where HES130/0.42 was associated with impaired renal function. Effects on haemostasis and fluid balance were investigated. Results: The rotational thromboelastometry (ROTEM®) parameters and chest tube drainage on the first postoperative morning (1POM) were comparable between the groups (p>0.05). However, patients in the HES group needed more blood and blood product transfusions. The total volume administered into the CPB circuit was lower in the HES than in the Ringer (RIN) group, 2905±1049 mL versus 3973±1207 mL (p=0.011), but there was no statistically significant difference in total fluid balance on the 1POM (5086±1660 mL in the HES group versus 5850±1514 mL in the RIN group, respectively). Conclusions: After complex cardiac surgery, the use of balanced 6% HES130/0.42 solution for CPB circuit priming did not impair haemostasis measured by ROTEM®, but it increased the need for transfusions. Fluid balance after CPB was less positive in the HES group, but, on the 1POM, it was comparable between the groups.

Thrombin in Myocardial Ischemia-Reperfusion During Cardiac Surgery

Thrombin is a multifunctional protease with procoagulant, pro-inflammatory, and pro-apoptotic effects. Thrombin has direct potentially adverse effects on the endothelium and on cardiomyocytes, which are independent of its procoagulant effects, and it has emerged as a possible mediator of ischemia-reperfusion injury. Several lines of experimental evidence specifically implicate thrombin to be involved in myocardial ischemia-reperfusion injury. Cardiopulmonary bypass increases thrombin generation progressively, but reperfusion after myocardial ischemia induces an additional distinct and rapid increase in thrombin generation. Clinical studies have shown that thrombin formation during cardiac surgery, especially during myocardial reperfusion, is involved with myocardial damage and impaired hemodynamic recovery. Therefore, strategies to improve thrombin control during cardiopulmonary bypass might be beneficial.

Adaptive lipid metabolism after ileal autotransplantation in pigs with proximal gut resection

BACKGROUND Transplantation of the small intestine impairs intestinal absorptive function, but the adaptive response of a segmental graft is unknown. The aim of this study was to investigate the effects of ileal autotransplantation on the adaptive absorption and metabolism of lipids in pigs that had undergone proximal gut resection. METHODS Serum lipids, plasma vitamins A and E, absorption and excretion of cholesterol, bile acids and fat, plasma cholesterol precursor and plant sterol proportions to cholesterol (respective markers of cholesterol synthesis and absorption), enteric structure, and transit were determined 4, 8, and 14 weeks after 75% proximal resection with (n = 15) or without (n = 15) autotransplantation of the remaining ileum. RESULTS As compared with pigs that underwent proximal gut resection, the additional autotransplantation reduced the adaptive increase in total serum and high-density lipoprotein cholesterol, plasma plant sterol proportions and vitamin E concentrations, cholesterol and fat absorption efficiency, and villus height (p < 0.05 for all) during the 14 postoperative weeks and resulted in increases of up to 4.6, 2.7, 1.3, and 2.1 times the plasma cholesterol precursors (p < 0.005), fecal excretion of bile acids (p < 0.0005), neutral steroids (p < 0.005), and net elimination of cholesterol (p < 0.0005), respectively. Cholesterol and fat absorption and plasma plant sterols were significantly enhanced between 8 and 14 weeks after autotransplantation (p < 0.05, p < 0.005, and p < 0.05, respectively), whereas fecal elimination of cholesterol remained increased until the end of the follow-up. CONCLUSIONS Autotransplantation of the ileum in pigs that have undergone proximal small bowel resection disturbs the adaptive absorption of cholesterol, bile acids, fat, and fat-soluble vitamins, resulting, through increased fecal elimination of cholesterol, in decreased serum cholesterol despite a marked compensatory increase in cholesterol synthesis.

Effects of transection and extrinsic denervation and a model of autotransplantation of the porcine jejunoileum on cholesterol biodynamics.

BACKGROUND/PURPOSE Small bowel transplantation impairs enteric function, necessitating transection, extrinsic denervation, and ischemia-reperfusion of the small intestine. The authors investigated how each of these nonimmunologic insides of the transplantation procedure modulates biodynamics of cholesterol and absorption of lipids. METHODS Twenty-three pigs with similar food, cholesterol, and fat intake underwent sham laparotomy (group 1), transection (group 2), extrinsic jejunoileal denervation (group 3), or a model of autotransplantation, including extrinsic jejunoileal denervation with in situ ischemia-reperfusion (group 4). Serum lipids, absorption, and excretion of cholesterol, bile acids, and fat were determined after 8 weeks. Plasma cholesterol precursors and plant sterols, respective markers of cholesterol synthesis, and absorption, were measured after 2 and 8 weeks. RESULTS When compared with sham laparotomy and transection groups, denervation and autotransplantation significantly decreased weight gain and increased plasma cholesterol precursors and fecal excretion of bile acids. In relation to sham operated animals, transection alone modestly increased plasma plant sterols at 2 weeks and biliary secretion and mass absorption of cholesterol. The latter changes were not observed after denervation or autotransplantation, ie, fractional and total absorption of cholesterol were significantly decreased in autotransplanted pigs when compared with transected controls. As compared with all the other groups, autotransplantation significantly increased bacterial metabolites of neutral sterols in feces and net fecal elimination of cholesterol, mainly as bile acids. CONCLUSIONS Extrinsic autonomic denervation of the jejunoileum, with or without synchronous ischemia-reperfusion, results in increased cholesterol synthesis, bile acid malabsorption, and decreased weight gain. Cholesterol malabsorption may develop gradually after intestinal autotransplantation, and even a short period of ischemia further impairs absorptive function of the denervated jejunoileum, resulting in increased fecal elimination of cholesterol mainly as bile acids.

Long-term results of vein sparing varicose vein surgery

The aim of this study was to assess the long-term functional outcome of vein sparing varicose vein surgery using handheld Doppler ultrasound (HHD). The series consisted of 171 consecutive day-case surgery patients operated on for uncomplicated lower limb varicose veins. Venous segments considered competent were spared based on clinical examination and HHD, which was performed preoperatively only when deemed necessary by the surgeon. After a mean follow-up of 8 years all patients were examined, a systematic HHD evaluation was performed, and the findings were classified according to the CEAP (Clinical, Etiological, Anatomical, Pathophysiological) classification, and disability scoring was performed. During the follow-up period 17% of the legs were reoperated or scheduled for reoperation. At follow-up 79% of all patients were asymptomatic without reoperation. In 24%, recurrent varicosities were present and venous reflux was demonstrated by HHD. Recurrence was two times more common when the saphenofemoral junction had originally been left intact. Of all recurrent cases, reflux was demonstrated in the long saphenous vein (LSV) above the knee in 62%, in the LSV below the knee in 7%, in the short saphenous vein (SSV) in 16%, in the posterior arch vein in 38%, and in a thigh perforator in 8%. Of the legs reoperated during the follow-up period 41% presented with venous reflux at the follow-up visit. We conclude that HHD efficiently reveals sites of reflux that have been missed during previous surgery and that a thorough preoperative HHD examination and marking of reflux routes is required.RésuméLe but de cette étude a été d’évaluer l’évolution fonctionnelle à long terme de la chirurgie conservatrice pour varices des membres inférieurs en utilisant un appareil écho doppler (ED) tenu à la main. Notre série a consisté en 171 patients consécutifs traités en ambulatoire pour varices des membres inférieurs non compliquées. Tout segment de veine considéré comme compétant a été épargné, basé sur les données de l’examen clinique et l’ED, qui a été réalisée en préopératoire lorsque le chirurgien l’a estimé nécessaire. Après un suivi moyen de huit ans, tous les patients ont été examinés, une évaluation systématique par ED a été réalisée et les résultats ont été classés selon la classification «CEAP» et la classification de handicap physique. Pendant le suivi, une réopération a été effectuée ou programmée pour 17% des jambes. Au suivi, 79% de tous les patients étaient asymptomatiques sans réopération. Chez 24%, on a trouvé des varicosités récidivantes et on a mis en évidence un reflux veineux par l’ED. La récidive a été deux fois plus fréquente lorsque l’on a laissé intacte initialement la jonction saphéno-fémorale. Dans tous les cas de récidives, on a mis en évidence un reflux dans la saphène majeure (SMa) (interne) au-dessus du genou dans 62% des cas, dans la SMa en dessous du genou dans 7%, dans la saphène mineure (Smi) (externe) chez 16%, dans la communicante veineuse postérieure chez 38%, et dans une perforante de la cuisse dans 8%. 41% des jambes réopérés dans la période de suivi ont eu un reflux veineux lors de la visite de contrôle. Nous concluons que TED décèle effectivement les sites de reflux qui ont été méconnus lors de l’acte chirurgical antérieur et qu’un examen ED préopératoire complet avec marquages des veines de reflux est nécessaire.ResumenEl objectivo de este estudio fue averiguar los resultados funcionales tardios, mediante ecoangiografia Doppler (HHD), del tratamiento quirûrgico controlado (conservador) de las varices. Nuestra casuistica comprende 171 pacientes con varices simples del miembro inferior, intervenidas ambulatoriamente. Los segmentos venosos considerados compétentes, tanto por la exploración clínica corno mediante el HHD preoperatorio (si tal prueba diagnóstica era requerida por el cirujano) se respetaron. Tras un seguimiento medio de 8 años, todos los pacientes fueron reexplorados, se realizó además, una evaluación sistemática con el HHD y los resultados se expresaron de acuerdo con la clasificación CEAP y en relación a su grado de incapacidad. Durante el periodo de seguimiento el 17% de los casos fueron reintervinieron o estaban programados para una reoperación. Al finalizar el seguimiento, el 79% de todos los pacientes no habían requerido reopersción alguna y estaban asintomäticos. En el 24% había recidiva varicosa, con reflujo venoso demostrado mediante el HHD. Las récidivas se duplicaron cuando en la operación inicial se habÌa respetado la conjunción safeno-femoral. En todas las récidivas se constatò reflujo en la vena safena interna (LSV): por encima de la rodilla en el 62% y por debajo en el 7%; se registrò reflujo en la safena externa en el 16%, en el arco venoso posterior en el 38% y en las perforantes del muslo en el 8% de los casos. El 41% de los miembros reintervenidos durante el periodo de seguimiento presentaban, ya en la primera visita, reflujo venoso. El HHD muestra claramente los puntos de reflujo que pasaron desapercibidos durante la intervención quirúrgica inicial. Por consigliente, es preciso realizar, en todos los casos, un HHD preoperatorio para demarcar todas las posibles rutas de reflujo.

Effects of Extrinsic Denervation With or Without Ischemia-Reperfusion Injury on Constitutional Mucosal Characteristics in Porcine Jejunoileum

We investigated the effects of jejunoileal denervation with or without ischemia–reperfusion on mucosal characteristics and small intestinal structure. Growing pigs underwent sham laparotomy, jejunal transection, or extrinsic jejunoileal denervation with or without in situ ischemia–reperfusion. Small intestinal morphology, crypt cell proliferation, enterocyte ultrastructure, and disaccharidase activities were analyzed from jejunum and ileum after eight weeks. Immunohistological analysis of the ileum showed no staining of catecholaminergic neurons after extrinsic denervation. Neural isolation of the jejunoileum with or without ischemia–reperfusion injury reduced weight gain and villous enterocyte density in the ileum, abolished the proximodistal gradient of sucrase activity, and increased mucosal thickness, villus height, and villus surface area in the ileum. However, gross jejunoileal morphology, crypt cell proliferation, and enterocyte ultrastructure remained unchanged. In conclusion, jejunoileal denervation in growing pigs selectively modulates constitutional mucosal characteristics in the ileum, presumably due to altered enterocyte turnover, without a decrease in small intestinal absorptive surface area. These changes are independent of short ischemia and subsequent reperfusion.

Long-term survival and quality of life after cardiac resuscitation following coronary artery bypass grafting

OBJECTIVE Follow-up studies of patients surviving emergency resternotomy, open cardiac massage, and additional emergency cardiac surgery following coronary artery bypass grafting (CABG) remain sparse and studies focusing on health-related quality of life are lacking. Our aim was to elucidate the long-term course of patients experiencing this hazardous complication. METHODS Between 1988 and 1999, 76 patients suffered sudden hemodynamic collapse following isolated CABG. All patients underwent emergency resternotomy and open cardiac massage. An emergency cardiac reoperation was performed in the 62 (82%) primary survivors. Additional 76 patients were pair-matched to the study patients on the basis of their preoperative characteristics and served as controls. Of the study patients, 41 (54%), and of the controls, 76, (100%) were discharged. In December 2009, all patients were traced with respect to mortality data and the health-related quality of life of living patients was studied using the RAND-36 Item Health Survey questionnaire. RESULTS Altogether 19 (73%) of the 26 study patients, and 38 (84%) of the 45 controls were available. After exclusion of the early deaths, the life expectancy was similar between the groups: neither overall (p = 0.60) nor cardiac (p = 0.64) survival differed significantly after a mean follow-up time of 15.1 ± 3.5 years. In addition, cardiac re-interventions were equally frequently required in both the groups. The RAND-36 scores were congruent (p = ns) between the groups and the age- and sex-matched national reference population in the health-related quality-of-life dimensions describing physical, mental, and social domains. CONCLUSIONS Patients who have survived severe hemodynamic collapse, open cardiac massage, and emergency cardiac reoperation following CABG achieve similar long-term prognosis in terms of survival and cardiac interventions as the pair-matched control patients. In addition, 15 years postoperatively, they have a good health-related quality of life, similar to that of an age- and sex-matched national reference population.