Kathryn Rouine-Rapp

The effects of inhaled nitric oxide on postoperative pulmonary hypertension in infants and children undergoing surgical repair of congenital heart disease

The role of inhaled nitric oxide in the immediate postbypass period after surgical repair of congenital heart disease is uncertain.In a controlled, randomized, double-blind study, we tested the hypothesis that inhaled nitric oxide (NO) would reduce pulmonary hypertension immediately after surgical repair of congenital heart disease in 40 patients with preoperative evidence of pulmonary hypertension (mean pulmonary arterial pressure [MPAP] exceeding 50% of mean systemic arterial pressure [MSAP]). Patients were then followed in the intensive care unit (ICU) to document the incidence of severe pulmonary hypertension. Of the patients, 36% (n = 13) emerged from bypass with MPAP >50% MSAP. In these patients, inhaled NO reduced MPAP by 19% (P = 0.008) versus an increase of 9% in the placebo group. No effect on MPAP was observed in patients emerging from bypass without pulmonary hypertension (n = 23). Inhaled NO was required five times in the ICU, always in the patients who had emerged from cardiopulmonary bypass with pulmonary hypertension (5 of 13 [38%] versus 0 of 23). We conclude that, in infants and children undergoing congenital heart surgery, inhaled NO selectively reduces MPAP in patients who emerge from cardiopulmonary bypass with pulmonary hypertension and has no effect on those who emerge without it. Implications: In a randomized double-blind study, inhaled nitric oxide selectively reduced pulmonary artery pressures in pediatric patients who developed pulmonary hypertension (high blood pressure in the lungs) immediately after cardiopulmonary bypass and surgical repair. (Anesth Analg 1998;87:46-51)

The Safety and Efficacy of Sevoflurane Anesthesia in Infants and Children with Congenital Heart Disease

We tested the hypothesis that sevoflurane is a safer and more effective anesthetic than halothane during the induction and maintenance of anesthesia for infants and children with congenital heart disease undergoing cardiac surgery. With a background of fentanyl (5 &mgr;g/kg bolus, then 5 &mgr;g · kg−1 · h−1), the two inhaled anesthetics were directly compared in a randomized, double-blinded, open-label study involving 180 infants and children. Primary outcome variables included severe hypotension, bradycardia, and oxygen desaturation, defined as a 30% decrease in the resting mean arterial blood pressure or heart rate, or a 20% decrease in the resting arterial oxygen saturation, for at least 30 s. There were no differences in the incidence of these variables; however, patients receiving halothane experienced twice as many episodes of severe hypotension as those who received sevoflurane (P = 0.03). These recurrences of hypotension occurred despite an increased incidence of vasopressor use in the halothane-treated patients than in the sevoflurane-treated patients. Multivariate stepwise logistic regression demonstrated that patients less than 1 yr old were at increased risk for hypotension compared with older children (P = 0.0004), and patients with preoperative cyanosis were at increased risk for developing severe desaturation (P = 0.049). Sevoflurane may have hemodynamic advantages over halothane in infants and children with congenital heart disease.

Detection of intraoperative segmental wall-motion abnormalities by transesophageal echocardiography : The incremental value of additional cross sections in the transverse and longitudinal planes

Because biplane and multiplane transesophageal echocardiography (TEE) are more complex and expensive than single-plane TEE, we performed this 00udy to determine whether the use of multiple single-plane (transverse) cross sections is as reliable for detection of left ventricular segmental wall-motion abnormalities (SWMA) as biplane TEE. We used biplane TEE to acquire nine standard cross sections of the left ventricle in 41 consecutive adults undergoing cardiac or vascular surgery. Six of these cross sections were in the transverse plane (i.e., achievable with single-plane TEE) and three in the longitudinal plane (i.e., achievable only with biplane or multiplane TEE). Each cross section was divided into myocardial segments for analysis. A total of 1810 segments were analyzed by independent investigators using a standardized evaluation system. Seventeen percent of all SWMA detected in this study were in the midpapillary transverse-plane cross section, an additional 48% in other transverse-plane cross sections, and 35% exclusively in the longitudinal-plane cross sections. Thus, most (65%), but not all, SWMA were in cross sections achievable with single-plane TEE. We conclude that the MP-T cross section should be the foundation for assessment of segmental function, but additional cross sections in the transverse and longitudinal planes are required for detection of the majority of segmental wall-motion abnormalities. (Anesth Analg 1996;83:1141-8)

Acute Hypovolemia May Cause Segmental Wall Motion Abnormalities in the Absence of Myocardial Ischemia

New segmental wall motion abnormalities (SWMA) detected by echocardiography are considered sensitive and specific markers of myocardial ischemia.However, we have observed new SWMA during pacing-induced reductions in left ventricular filling, which resolved immediately with cessation of the atrial pacing and simultaneous restoration of filling. Therefore, we designed this study to determine whether acute reduction in filling can induce new SWMA in the absence of ischemia. Institution of cardiopulmonary bypass was used as a clinical model of acute reduction in filling, and a beat-by-beat analysis of left ventricular contraction, filling, blood pressures, and electrocardiogram was performed when the drainage of blood to the cardiopulmonary bypass machine rapidly emptied the heart. Acute reduction in filling induced new SWMA in 4 of 38 study patients. All 4 patients had preexisting abnormalities of left ventricular contraction, but translocation of these preexisting SWMA did not explain the new SWMA, nor did myocardial ischemia. We conclude that acute reduction in left ventricular filling can cause new SWMA in the absence of ischemia. This finding limits the usefulness of new SWMA as a marker of ischemia in the presence of acute reduction in filling, such as that secondary to severe hypovolemia. Implications: This study documented that acute reduction in cardiac filling can be associated with new systolic wall motion abnormalities detected by transesophageal echocardiography in the absence of documented myocardial ischemia. These findings indicate that segmental wall motion may not be a valid marker for ischemia in the setting of acute hypovolemia. (Anesth Analg 1997;85:1252-7)

Extracellular potassium concentrations in red blood cell suspensions after irradiation and washing

BACKGROUND: Extracellular potassium concentration [K+e] increases with duration of red blood cell storage. Sometimes red blood cells (RBC) are washed before transfusion to infants to reduce [K+e] of these components. AABB standards permit storage of washed RBCs at 4°C for 24 hours. The [K+e] of washed RBCs during storage is not known. Experiments were performed to provide those data.

Congenital heart disease in the adult: a review with internet-accessible transesophageal echocardiographic images.

T he number of adults recognized with congenital heart disease (CHD) has increased dramatically over the past five decades because of significant advances in diagnosis and medical and surgical care. At the moment, the population of adults with CHD (ACHD) in the United States is estimated at approximately one million (1). For the first time, the number of adults with congenital cardiovascular malformations equals the number of children with these disorders. With additional refinements in surgical techniques and definitive repair at an earlier age, this patient group is likely to increase even further. Survival rates in CHD are influenced by many factors, including year of birth, age at diagnosis, complexity of the pathology, and whether the lesion(s) has been palliated or surgically corrected (Table 1) (1). As survival and life expectancy continue to improve, a growing number of unoperated, palliated, and “repaired” individuals require surgical interventions or other procedures related or unrelated to their heart disease. The care of these patients is becoming more frequent in all surgical settings, including tertiary care facilities, ambulatory centers, and labor and delivery suites. Adults with CHD may come to the attention of anesthesiologists for various indications including:

Effect of enalaprilat on postoperative hypertension after surgical repair of coarctation of the aorta.

Objective Hypertension in pediatric patients after surgical repair of coarctation of the aorta can be difficult to control and may lead to morbidity. The renin-angiotensin system mediates at least part of this hypertension. Enalaprilat, the only intravenous angiotensin-converting enzyme inhibitor, is used to treat hypertension in pediatric patients in other settings. However, its effect on postoperative hypertension during the early postoperative period in patients undergoing surgical repair of coarctation of the aorta is unknown. Design Prospective, randomized, double-blind study. Setting Operating room and the pediatric intensive care unit. Patients Fourteen consecutive pediatric patients between the ages of 1 and 18 yrs scheduled to undergo surgical repair of coarctation of the aorta. Interventions Patients were randomized to receive enalaprilat or saline placebo. Infusions were begun intraoperatively within 15 mins of aortic repair and repeated every 6 hrs. Measurements and Main Results Plasma renin activity was measured at baseline and on postoperative day 1. Blood pressure was determined at 30 mins and at 2, 4, and 6 hrs after infusion and scored relative to the preoperative blood pressure. The blood pressure in the enalaprilat group was consistently lower at 30 mins, 2 hrs, and 4 hrs after infusion (p < .05), but not at 6 hrs. Plasma renin activity was significantly lower in the placebo group on postoperative day 1. Length of stay in the pediatric intensive care unit trended shorter in the treated group. Conclusions Conclusions are limited by a small cohort. Angiotensin-converting enzyme inhibitor therapy resulted in improved blood pressure control after coarctation repair. Further improvement of blood pressure control may be achievable by use of a larger dose of enalaprilat or a 4-hr enalaprilat-dosing interval.

Detection of Intraoperative Segmental Wall Motion Abnormalities by Transesophageal Echocardiography

Because biplane and multiplane transesophageal echocardiography (TEE) are more complex and expensive than single-plane TEE, we performed this study to determine whether the use of multiple single-plane (transverse) cross sections is as reliable for detection of left ventricular segmental wall-motion abnormalities (SWMA) as biplane TEE. We used biplane TEE to acquire nine standard cross sections of the left ventricle in 41 consecutive adults undergoing cardiac or vascular surgery. Six of these cross sections were in the transverse plane (i.e., achievable with single-plane TEE) and three in the longitudinal plane (i.e., achievable only with biplane or multiplane TEE). Each cross section was divided into myocardial segments for analysis. A total of 1810 segments were analyzed by independent investigators using a standardized evaluation system. Seventeen percent of all SWMA detected in this study were in the midpapillary transverse-plane cross section, an additional 48% in other transverse-plane cross sections, and 35% exclusively in the longitudinal-plane cross sections. Thus, most (65%), but not all, SWMA were in cross sections achievable with single-plane TEE. We conclude that the MP-T cross section should be the foundation for assessment of segmental function, but additional cross sections in the transverse and longitudinal planes are required for detection of the majority of segmental wall-motion abnormalities.

Perioperative management of a neurosurgical patient with a meningioma and recent coronary artery stent

Patients who undergo placement of a drug-eluting coronary artery stent are prescribed dual antiplatelet therapy for one year. Early cessation of this therapy is a risk factor for a major adverse cardiac event, especially in high-risk patients. The perioperative physician team must evaluate the risk of surgical bleeding relative to the thrombotic risk during the perioperative period in patients taking dual antiplatelet therapy who must undergo intracranial neurosurgery. A 67 year old woman presented with right-sided hearing loss. Neurologic examination was significant for early papilledema and decreased hearing in the right ear. Magnetic resonance imaging showed a > 5 cm contrast-enhancing mass within her right-middle fossa with surrounding vasogenic edema and midline shift. Additional medical history was significant for diabetes, hypertension, and placement of a drug-eluting stent for coronary artery disease three months before her initial presentation. Medications included aspirin and clopidogrel. She underwent embolization of the middle meningeal arterial supply to the meningioma, then was admitted to the hospital for perioperative management of her antiplatelet therapy and telemetry monitoring. Her clopidogrel was stopped and aspirin continued perioperatively. An intravenous infusion of the antiplatelet drug, eptifibatide, replaced clopidogrel and was continued until 8 hours prior to surgical incision. During resection of the meningioma, no unusual surgical bleeding was noted. The patient was discharged on postoperative day 3 with satisfactory recovery.

Reliability of Intraoperative Contrast Transesophageal Echocardography for Detecting Interatrial Communications in Patients With Other Congenital Cardiovascular Malformations

The reliability of contrast transesophageal echocardiography (TEE) for diagnosing atrial communication has not been studied previously in patients with congenital heart disease. We prospectively evaluated the validity of intraoperative contrast TEE for determining atrial septal patency in a group of patients with congenital heart disease who underwent surgery using direct inspection for defi nitive diagnosis. Our study was prompted by the potential for surgical complications from paradoxic systemic air embolism 1 and observed cases of interatrial communications that were undetected despite a thorough preoperative assessment and intraoperative TEE including contrast studies. One child had severe neurologic damage due to systemic air embolization during open right-sided cardiac surgery with a beating heart.