Background Cardiac surgery requiring cardiopulmonary bypass is associated with platelet activation. Because platelets are increasingly recognized as important effectors of ischemia and end-organ inflammatory injury, the authors explored whether postoperative nadir platelet counts are associated with acute kidney injury (AKI) and mortality after coronary artery bypass grafting (CABG) surgery. Methods The authors evaluated 4,217 adult patients who underwent CABG surgery. Postoperative nadir platelet counts were defined as the lowest in-hospital values and were used as a continuous predictor of postoperative AKI and mortality. Nadir values in the lowest 10th percentile were also used as a categorical predictor. Multivariable logistic regression and Cox proportional hazard models examined the association between postoperative platelet counts, postoperative AKI, and mortality. Results The median postoperative nadir platelet count was 121 × 109/l. The incidence of postoperative AKI was 54%, including 9.5% (215 patients) and 3.4% (76 patients) who experienced stages II and III AKI, respectively. For every 30 × 109/l decrease in platelet counts, the risk for postoperative AKI increased by 14% (adjusted odds ratio, 1.14; 95% CI, 1.09 to 1.20; P < 0.0001). Patients with platelet counts in the lowest 10th percentile were three times more likely to progress to a higher severity of postoperative AKI (adjusted proportional odds ratio, 3.04; 95% CI, 2.26 to 4.07; P < 0.0001) and had associated increased risk for mortality immediately after surgery (adjusted hazard ratio, 5.46; 95% CI, 3.79 to 7.89; P < 0.0001). Conclusion The authors found a significant association between postoperative nadir platelet counts and AKI and short-term mortality after CABG surgery.

It has been more than 50 yr since the landmark article in which Holliday and Segar (Pediatrics 1957;19:823-32) proposed the rate and composition of parenteral maintenance fluids for hospitalized children. Much of our practice of fluid administration in the perioperative period is based on this article. The glucose, electrolyte, and intravascular volume requirements of the pediatric surgical patient may be quite different than the original population described, and consequently, use of traditional hypotonic fluids proposed by Holliday and Segar may cause complications, such as hyperglycemia and hyponatremia, in the postoperative surgical patient. There is significant controversy regarding the choice of isotonic versus hypotonic fluids in the postoperative period. We discuss the origins of perioperative fluid management in children, review the current options for crystalloid fluid management, and present information on colloid use in pediatric patients.

Background Postoperative tachyarrhythmias remain a common complication after congenital cardiac surgery. A recent case-series has shown that dexmedetomidine, an alpha-2 adrenoreceptor agonist can have a therapeutic role in supraventricular tachyarrhythmias for either cardioversion to sinus rhythm or heart rate control. The present study was performed to determine if routine perioperative use of dexmedetomidine can decrease the incidence of supraventricular and ventricular tachyarrhythmias. Methods Prospective cohort study of pediatric patients undergoing cardiothoracic surgery. Thirty-two patients who were initiated on dexmedetomidine infusion (DEX-group) before surgery were compared with 20 patients who did not receive dexmedetomidine (control-group). Results Dexmedetomidine was started after anesthesia induction and continued through surgery and postoperative period for 38±4 hours at a mean dose of 0.76 ±0.04 mcg/kg/hr. Ten patients in control-group and 2 in DEX-group (p=0.001) had a total of 16 episodes of tachyarrhythmias. The incidence of ventricular tachycardia was 25% vs.0% (p=0.01) and of supraventricular arrhythmias 25% vs. 6% (p=0.05) in the control and DEX-group respectively. Two patients in the control-group and 1 in the Dex-group had transient complete heart block. Control-group had a higher heart rate 141 ± 5 vs.127 ±3 bpm (p=0.03), more sinus tachycardia episodes 40% vs. 6% (p=0.008), required more antihypertensives with nitroprusside 20 ± 7 vs.4 ± 1 mcg/kg (p=0.004) and nicardipine 13 ± 5 vs.2 ± 1 mcg/kg (p=0.02) and required more fentanyl 39 ± 8 vs.19 ± 3 mcg/kg (p=0.005). Conclusions Perioperative use of dexmedetomidine is associated with significantly decreased incidence of ventricular and supraventricular tachyarrhythmias without significant adverse effects.