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Over the period 2009 - 2010, Clinics has published a relatively large number of original studies dealing with the cardiovascular and pulmonary system. Twenty of these have attracted significant numbers of citations within this relatively short time span. This short review covers these aspects of recent research with direct interest to cardiologists. Articles were grouped under three headings: Cardiology, Pneumology and Multidisciplinary.

Objective: The objective of this study was to analyze the hemodynamic and respiratory changes caused by CO2 laparoscopy in an experimental model of diaphragmatic injury., Methods: Fifteen animals chosen at random were submitted to diaphragmatic injury by means of CO2 laparoscopy. Evaluation consisted of drawing blood samples to analyze blood gases, as well as the hemodynamic and respiratory variables., Results: Alterations occurred in APA, CPP, PAO2, ASO2, VSO2., Conclusion: We concluded that videolaparoscopy with pneumoperitoneum pressure under 15 mmHg is a safe procedure in patients with diaphragmatic injuries because this pressure level does not cause hemodynamic changes, such as decrease of the cardiac output.

Background and Objectives: Bleeding causing hemorrhagic shock usually requires surgical treatment under general anesthesia. Anesthetic drugs may further compromise hemodynamics. The objective was to compare the hemodynamic effects of ketamine and etomidate during anesthetic induction in dogs submitted to an experimental model of hemorrhagic shock and resuscitation., Methods: Thirty-two mongrel dogs were submitted to a pressure-controlled hemorrhagic shock, resuscitation and anesthetic induction model. After achieving the target pressure of 40 mmHg, they were randomly assigned in two groups according to the resuscitation fluid to be used: NaCl 0.9% (32 mL.kg-1) and NaCl 7.5% (4 mL.kg-1). After volume infusion, these groups were reassigned according to anesthetic drug used: GI) NaCl 0.9% and ketamine; GII) NaCl 7.5% and ketamine; GIII) NaCl 0.9% and etomidate; and GIV) NaCl 7.5% and etomidate. Hemodynamic measurements were obtained at five moments: (M0) baseline; (M1) after bleeding to shock; (M2) after volume expansion; (M3) 5 minutes after anesthetic induction; (M4) 15 minutes after anesthetic induction. Statistical analysis was performed using Student t test and two way ANOVA. Value of p lower than 0.05, was considered significant., Results: After shock, both solutions restored hemodynamics to baseline values. Independently of anesthetic agent or expansion solution used, mean arterial pressure remained unaltered for all groups after induction. Central venous pressure, heart rate, pulmonary capillary wedge pressure and pulmonary vascular resistance index increased significantly after ketamine infusion. Cardiac index, systemic vascular resistance index and oxygen transport variables remained stable in all groups., Conclusions: Etomidate or ketamine were able to maintain hemodynamic stability in dogs undergoing severe hemorrhagic shock treated with NaCl 0.9% or NaCl 7.5%.

Purpose: To evaluate the effects of SSH resuscitation on systemic and splanchnic hemodynamic variables in an experimental model of controlled hemorrhagic shock., Methods: Ten mongrel dogs were bled (20 ml/min) to a target mean arterial pressure (MAP) of 40+/-5 mmHg. After 30 minutes of shock, animals received SSH infused in 5-minute and they were observed for 60 minutes thereafter. Systemic hemodynamics were evaluated through a Swan-Ganz and arterial catheters while gastrointestinal tract perfusion by a catheter inside the portal vein, an ultrasonic flowprobe around portal vein blood flow (PVBF) and a gastric tonometer. Splanchnic oxygen delivery and consumption, intramucosal pH and veno-arterial, portal-arterial and mucosal-arterial pCO2-gradients (D(ap-a)pCO2, D(vp-a)pCO2 e D(t-a)pCO2, respectively) were assessed., Results: Hemorrhage (29.8+/-2.4 ml/Kg) induced significant decreases in MAP (125+/-6 to 42+/-1 mmHg), in CO (1.9+/-0.2 to 0.6+/-0.1 L/min), and PVBF (504+/-73 to 126+/-12 ml/min) while significant increases were detected in D(ap-a)pCO2 (5.3+/-0.8 to 19.9+/-1.6 mmHg) D(vp-a)pCO2 (5.4+/-1.4 to 22.6+/-2.1 mmHg) and D(t-a)pCO2 (6.1+/-1.1 to 43.8+/-7.5 mmHg). SSH infusion promoted only partial benefits in systemic and splanchnic blood flows. Reduced pCO2 gradients but fewer effects in D(t-a)pCO2 were observed., Conclusion: The SSH infusion promoted partial systemic and splanchnic hemodynamic benefits. Those benefits were especially poor at the splanchnic microcirculation, as evaluated by D(t-a)pCO2. In addition, systemic and regional oxygen-derived variables do not reflect the regional microcirculation disturbances. Gastrointestinal tonometry clearly represents a useful tool for monitoring splanchnic perfusion in patients in hemodynamic shock.

Background: Mesenteric ischemia is a life-threatening emergency with a mortality rates still ranging between 60% and 100%., Aim: To evaluate the systemic and regional pCO2 gradients changes induced by mesenteric ischemia-reperfusion injury. In addition, we sought to determine if other systemic marker of splanchnic hypoperfusion could detect the initial changes in intestinal mucosal microcirculation after superior mesenteric artery occlusion., Methods: Seven pentobarbital anesthetized mongrel dogs (20.6 +/- 1.1 kg) were subjected to superior mesenteric artery occlusion for 45 minutes, and followed for an additional 120 minutes. Systemic hemodynamic was evaluated through a Swan-Ganz and arterial catheters, while gastrointestinal tract perfusion by superior mesenteric vein and jejunal serosal blood flows (ultrasonic flowprobe). Intestinal oxygen delivery, extraction and consumption (DO2intest, ERO2intest and VO2intest, respectively), intramucosal pH (gas tonometry), and mesenteric-arterial and mucosal arterial pCO2 gradients (D(vm-a)pCO2 and D(t-a)pCO2, respectively) were calculated., Results: Superior mesenteric artery occlusion was not associated with significant changes on systemic hemodynamics parameters. A significant increase of D(vm-a)pCO2 (1.7 +/- 0.5 to 5.7 +/- 1.8 mm Hg) and D(t-a)pCO2 (8.2 +/- 4.8 to 48.7 +/- 4.6 mm Hg) were detected. During the reperfusion period a significant decrease on DO2intest (67.7 +/- 9.9 to 38.8 +/- 5.3 mL/min) and a compensatory increase on ERO2intest from 5.0 +/- 1.1% to 12.4 +/- 2.7% was observed., Conclusion: We conclude that gas tonometry can detect the mesenteric blood flow disturbances sooner than other analyzed parameters. Additionally, we demonstrated that changes on systemic or regional pCO2 gradients are not able to detect the magnitude of intestinal mucosal blood flow reduction after mesenteric ischemia-reperfusion injury.

Purpose: To study the early hemodynamic effects of the rapid infusion of 7.5g/dl NaCl/ 6g/dl dextran-70 solution in dogs submitted to hemorrhagic shock., Methods: Mongrel dogs were anesthetized with pentobarbital and a electromagnetic flowmeter probe was placed around the ascending aorta or the portal vein. By external bleeding the arterial pressure was lowered to 40mmHg and held for 30min. The animals received a 4ml/kg infusion of the hypertonic solution in 90s. Arterial blood pressure and flow were registered continuously during 3min and the derived hemodynamic variables were calculated at regular time intervals., Results: The total plasma protein concentration decreased and the cardiac output showed a continuous elevation during the infusion. The arterial blood pressure showed two oscillations and then decreased during a short period of time. This moment was coincident with the initial increase of the portal flow and preceded the elevation of the systemic vascular resistance and the arterial pressure., Conclusion: The rapid infusion of hypertonic NaCl/dextran solution to dogs in hemorrhagic shock determines immediate and intense hemodynamic effects. During the infusion period there is volemic expansion and the cardiac output increases rapidly. The arterial pressure shows oscillations and decreases as a consequence of visceral arterial dilation before starting its final elevation that occurs as the vascular resistance increases.