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Biomedical subjects

R A Jonas

Publications and source records attributed to R A Jonas.

At least 55 records · Page 3Linked to original sources
PubMed1999

Developmental and neurological status of children at 4 years of age after heart surgery with hypothermic circulatory arrest or low-flow cardiopulmonary bypass.

BACKGROUND: It is not known whether developmental and neurological outcomes in the preschool period differ depending on whether the predominant vital organ support strategy used in infant heart surgery was total circulatory arrest (CA) or low-flow cardiopulmonary bypass. METHODS AND RESULTS: Infants with D-transposition of the great arteries who underwent an arterial-switch operation were randomly assigned to a support method consisting predominantly of CA or low-flow cardiopulmonary bypass. Developmental and neurological status were evaluated blindly at 4 years of age in 158 of 163 eligible children (97%). Neither IQ scores nor overall neurological status were significantly associated with either treatment group or duration of CA. The CA group scored lower on tests of motor function (gross motor, P=0.01; fine motor, P=0.03) and had more severe speech abnormalities (oromotor apraxia, P=0.007). Seizures in the perioperative period, detected either clinically or by continuous electroencephalographic monitoring, were associated with lower mean IQ scores (12.6 and 7.7 points, respectively) and increased risk of neurological abnormalities (odds ratios, 8.4 and 5.6, respectively). The performance of the full cohort was below expectations in several domains, including IQ, expressive language, visual-motor integration, motor function, and oromotor control. CONCLUSIONS: Use of CA to support vital organs during open heart surgery in infancy is associated, at the age of 4 years, with worse motor coordination and planning but not with lower IQ or with worse overall neurological status.

Cardiac Surgical Procedures↗
PubMed1999

Preoperative management of pulmonary venous hypertension in hypoplastic left heart syndrome with restrictive atrial septal defect.

A severely restrictive atrial septal defect (ASD) in neonates with hypoplastic left heart syndrome (HLHS) results in pulmonary venous hypertension, pulmonary edema, and intractable hypoxia. Between January 1983 and June 1998, 21 of 355 neonates presenting with HLHS (5.9%) underwent cardiac catheterization at median age 1 day (range 0 to 25), for creation or enlargement of a restrictive or absent interatrial communication. One patient died during preliminary angiography. Three underwent blade septostomy with 2 procedure-related deaths, and 1 had balloon atrial septostomy (BAS); all 4 died before surgical intervention. Fifteen underwent Brockenbrough atrial septoplasty with transatrial needle puncture and serial balloon dilations of the new ASD, 5 after unsuccessful BAS. The most recent patient had a stent placed across the atrial septum after transatrial needle puncture. In the 16 patients treated with septoplasty or stent, oxygen saturation increased from 50 +/- 4% to 83 +/- 2% (p <0.0001) and transatrial pressure gradient decreased from 16 +/- 1 to 6 +/- 1 mm Hg (p <0.0001). One patient died awaiting transplantation, supportive care only was requested in 1, and 14 underwent stage 1 palliation. Eight of 14 (57%) survived to hospital discharge. Six of 7 (86%) survived bidirectional Glenn and the 3 who have undergone fenestrated Fontan are alive. In neonates with HLHS, a restrictive ASD resulting in profound cyanosis demands urgent intervention. BAS is frequently unsuccessful and blade septostomy has high mortality. Pulmonary venous hypertension can be adequately relieved by Brockenbrough atrial septoplasty or stenting, allowing stabilization before reconstructive surgery or while awaiting transplant.

Cardiac Catheterization↗
PubMed1999

Left ventricular assist device improves survival in children with left ventricular dysfunction after repair of anomalous origin of the left coronary artery from the pulmonary artery.

BACKGROUND: Repair of anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) in infants carries a high operative risk, particularly in infants with myocardial infarction and poor left ventricular function. The marked recovery of left ventricular function reported late after repair, however, suggests that an aggressive approach to repair should be undertaken. METHODS: Of 31 children undergoing primary repair of ALCAPA at our institution from 1987 to 1996, 26 were infants (6 weeks to 9 months old). All but 2 had severe left ventricular dysfunction, and 8 had moderate to severe mitral regurgitation. Seven children were unable to be weaned from cardiopulmonary bypass because of poor left ventricular function and elevated left atrial pressure. These 7 children were placed on mechanical left ventricular support using a centrifugal pump, with support ranging from 2.2 to 70.6 hours. RESULTS: One child died shortly after the start of left ventricular assist (2.2 hours), and another died of arrhythmia within 24 hours after successful decannulation. All 5 survivors had significant improvement in left ventricular function, with 2 requiring late mitral valve repair. CONCLUSIONS: Infants with ALCAPA who have severe left ventricular dysfunction represent a higher risk group for repair. However, with use of mechanical circulatory support in those unable to be weaned from cardiopulmonary bypass, a high survival rate can be achieved with good long-term recovery. We conclude that an aggressive approach to early repair in all children with ALCAPA is warranted, regardless of the degree of left ventricular dysfunction.

Cardiopulmonary Bypass↗
PubMed1999

Valved homograft conduit repair of the right heart in early infancy.

BACKGROUND: Valved homograft conduit repair in neonates and young infants creates a physiologically normal biventricular circulation, and unlike shunts, avoids surgery on the branch pulmonary. METHODS: Retrospective chart review was used for 84 patients operated on between 1990 and 1995 (mean age 26+/-28 days, mean weight 3.3+/-0.8 kg) undergoing homograft conduit repair in the first 3 months of life. Cases were divided into simple and complex, eg, absent pulmonary valve syndrome or associated interrupted arch. Mean homograft size was 9.0+/-2 mm. RESULTS: Early mortality was 4.7% (simple) and 30% (complex). Mean hospital stay was 18 days. Mean follow-up was 34 months. Thirty-seven (47%) patients underwent conduit replacement. Median time to reoperation was 3.1 years. Mean size of replacement homograft was 17+/-2 mm. There were no deaths at reoperation. Mean hospital stay at conduit change was 6.3 days. Probability of survival at 5 years is 75%. CONCLUSIONS: Biventricular repair employing a conduit can be performed safely in noncomplex anomalies in the first 3 months of life. Time interval until repeat surgery is relatively short but equal or greater than that with most palliative procedures.

Bioprosthesis↗
PubMed1999

Forty-one years of surgical experience with congenital supravalvular aortic stenosis.

OBJECTIVE: Several techniques for symmetric reconstruction of the aortic root in congenital supravalvular aortic stenosis have been developed, but it remains unclear whether these prove superior to patch enlargement of the noncoronary sinus alone. We reviewed our experience with surgical treatment of supravalvular aortic stenosis and investigated the impact of the surgical technique on long-term results. METHODS AND RESULTS: Seventy-five patients underwent operations to treat congenital supravalvular aortic stenosis at our institution between 1957 and 1998. Surgical procedures included patch enlargement of the noncoronary sinus only (n = 34), inverted bifurcated patch plasty (n = 35), and 3-sinus reconstruction of the aortic root (n = 6). There were 7 early deaths. Among those who survived the operation, 100% were alive at 5 years, 96% were alive at 10 years, and 77% were alive at 20 years. According to time-related analysis diffuse stenosis of the ascending aorta proved a risk factor for both survival and reoperation (P <.01 for each). Patients with multiple-sinus reconstructions of the aortic root accounted for only 2 of the 14 reoperations and none of the late deaths (both P <.001). Residual gradients were lower after multiple-sinus reconstruction of the aortic root (median 10 mm Hg vs 20 mm Hg for patch enlargement of the noncoronary sinus only, P =. 008), as was the prevalence of moderate aortic regurgitation at follow-up (3% vs 22%, P =.05). CONCLUSIONS: Results of operations for supravalvular aortic stenosis improved greatly after the introduction of more symmetric reconstructions of the aortic root. Multiple-sinus reconstructions (inverted bifurcated patch plasty and 3-sinus reconstruction) resulted in superior hemodynamics and were associated with reductions in both mortality rate and need for reoperation.

Aortic Valve Stenosis↗
PubMed1999

Improved results with selective management in pulmonary atresia with intact ventricular septum.

OBJECTIVE: Late outcome of neonatal pulmonary atresia with intact ventricular septum remains poor in most reported series. We have followed a selective approach toward either single ventricle repair versus complete or partial biventricular repair based on the presence of right ventricle-dependent coronary circulation and growth of the right ventricle. METHODS: A retrospective chart review was conducted of 47 patients who underwent surgery between January 1991 and September 1998. RESULTS: Sixteen (34%) patients had a right ventricle-dependent coronary circulation, with a tricuspid valve Z-score of -3.0 +/- 0.66 versus -2.0 +/- 0.95 (P =.002) for those without a right ventricle-dependent coronary circulation. A systemic-pulmonary artery shunt only was performed in all patients with a right ventricle-dependent coronary circulation, with 1 death. Fourteen of 16 patients with a right ventricle-dependent coronary circulation underwent a bidirectional Glenn shunt at a median of 9 months after their first operation, 9 of whom have had a Fontan procedure (no deaths). In the 31 (66%) patients without a right ventricle-dependent coronary circulation, 6 patients underwent only a systemic-pulmonary artery shunt, 23 had a shunt and right ventricular decompression, and 2 had only a transannular patch. In this group, 10 patients received a 2-ventricle repair, 6 a 1. 5-ventricle repair, and 8 patients had a Fontan procedure. There was 1 early death and the overall survival was 98% at 1 year, 5 years, and 7 years. CONCLUSIONS: If patients are stratified well, excellent survival can be achieved in the treatment of pulmonary atresia with intact ventricular septum. This result may be at the price of achieving a 1-ventricle as opposed to a 2-ventricle repair.

Actuarial Analysis↗
PubMed1999

Oxygenation strategy and neurologic damage after deep hypothermic circulatory arrest. I. Gaseous microemboli.

OBJECTIVES: Recent studies suggest that myocardial reperfusion injury is exacerbated by free radicals when pure oxygen is used during cardiopulmonary bypass. Partial replacement of the oxygenator gas mixture with nitrogen, however, such as has already been adopted clinically in many centers, could increase the risk of gaseous nitrogen microembolus formation and therefore of brain damage because of the low solubility of nitrogen, particularly under conditions of hypothermia. METHODS: Ten 7- to 10-kg piglets were cooled for 30 minutes to 15 degrees C on cardiopulmonary bypass and then rewarmed for 40 minutes to 37 degrees C. In 5 piglets cardiopulmonary bypass was normoxic and in 5 it was hyperoxic. In each group 3 bubble oxygenators without arterial filters and 2 membrane oxygenators with filters were used. Cerebral microemboli were monitored continuously by carotid Doppler ultrasonography (8 MHz) and intermittently by fluorescence retinography. RESULTS: Embolus count was greater with lower rectal temperature (P <.001), use of a bubble oxygenator (P <.001), and lower oxygen concentration (P =.021) but was not affected by the temperature gradient between blood and body during cooling or rewarming. CONCLUSIONS: Gaseous microemboli are increased with normoxic perfusion, but this is only important if a bubble oxygenator without a filter is used.

Animals↗
PubMed1999

Oxygenation strategy and neurologic damage after deep hypothermic circulatory arrest. II. hypoxic versus free radical injury.

OBJECTIVES: Laboratory studies suggest that myocardial reperfusion injury is exacerbated by free radicals when pure oxygen is used during cardiopulmonary bypass. In phase I of this study we demonstrated that normoxic perfusion during cardiopulmonary bypass does not increase the risk of microembolic brain injury so long as a membrane oxygenator with an arterial filter is used. In phase II of this study we studied the hypothesis that normoxic perfusion increases the risk of hypoxic brain injury after deep hypothermia with circulatory arrest. METHODS: With membrane oxygenators with arterial filters, 10 piglets (8-10 kg) underwent 120 minutes of deep hypothermia and circulatory arrest at 15 degrees C, were rewarmed to 37 degrees C, and were weaned from bypass. In 5 piglets normoxia (PaO2 64-181 mm Hg) was used during cardiopulmonary bypass and in 5 hyperoxia (PaO2 400-900 mm Hg) was used. After 6 hours of reperfusion the brain was fixed for histologic evaluation. Near-infrared spectroscopy was used to monitor cerebral oxyhemoglobin and oxidized cytochrome a,a3 concentrations. RESULTS: Histologic examination revealed a significant increase in brain damage in the normoxia group (score 12.4 versus 8.6, P =.01), especially in the neocortex and hippocampal regions. Cytochrome a,a 3 and oxyhemoglobin concentrations tended to be lower during deep hypothermia and circulatory arrest in the normoxia group (P =.16). CONCLUSIONS: In the setting of prolonged deep hypothermia and circulatory arrest with membrane oxygenators, normoxic cardiopulmonary bypass significantly increases histologically graded brain damage with respect to hyperoxic cardiopulmonary bypass. Near-infrared spectroscopy suggests that the mechanism is hypoxic injury, which presumably overwhelms any injury caused by increased oxygen free radicals.

Animals↗
PubMed1999

A novel sialyl Lewis X analog attenuates cerebral injury after deep hypothermic circulatory arrest.

BACKGROUND: The initial step in the inflammatory process, which can be initiated by cardiopulmonary bypass and by ischemia/reperfusion, is mediated by interactions between selectins on endothelial cells and on neutrophils. We studied the effects of selectin blockade using a novel Sialyl Lewis X analog (CY-1503) on recovery after deep hypothermic circulatory arrest in a piglet model. METHODS: Twelve Yorkshire piglets were subjected to cardiopulmonary bypass, 30 minutes of cooling, 100 minutes of circulatory arrest at 15 degrees C, and 40 minutes of rewarming. Five animals received a bolus of 60 mg/kg of CY-1503 and an infusion (3 mg/kg per hour) for 24 hours from reperfusion (group O), and 7 randomly selected control piglets received saline solution (group C). Body weight and total body water content were evaluated 3 hours and 24 hours after reperfusion by a bio-impedance technique. Neurologic recovery of animals was evaluated daily by neurologic deficit score (0 = normal, 500 = brain death) and overall performance categories (1 = normal, 5 = brain death). The brain was fixed in situ on the fourth postoperative day and examined by histologic score (0 = normal, 5+ = necrosis) in a blinded fashion. RESULTS: Two of 7 animals in group C died. The neurologic deficit score was significantly lower in group O than in group C (postoperative day 1, P <.001; postoperative day 2, P =.02). The overall performance category was significantly lower in group O than in group C on postoperative day 2 (P =.01). Percentage total body water after cardiopulmonary bypass was significantly higher in group C than in group O (P =.03). Histologic score tended to be higher in group C than in group O, but this difference did not reach statistical significance (group O = 0.5 +/- 0.7; group C = 1.3 +/- 1.off CONCLUSION: Blockade of selectin adhesion molecules by saturation with a Sialyl Lewisx analog accelerates recovery after 100 minutes of deep hypothermic circulatory arrest in a piglet survival model.

Animals↗
PubMed1999

Mechanical circulatory support in children with cardiac disease.

OBJECTIVE: To review the experience from a single center that uses both extracorporeal membrane oxygenation and ventricular assist devices for children with cardiac disease requiring mechanical circulatory support. METHODS: A retrospective chart review was performed for all pediatric patients with cardiac disease who required support with extracorporeal membrane oxygenation or ventricular assist devices. Statistical analysis of the impact of multiple clinical parameters on survival was performed. RESULTS: From 1987 through 1996 we provided mechanical circulatory support for children with a primary cardiac diagnosis using extracorporeal membrane oxygenation (67 patients) and ventricular assist devices (29 patients). Twenty-seven of 67 (40.3%) patients supported with extracorporeal membrane oxygenation and 12 of 29 (41.4%) patients supported with ventricular assist devices survived to hospital discharge. Failure of return of ventricular function within 72 hours of the institution of support was an ominous sign in patients supported with either modality. Univariate analysis revealed the serum pH at 24 hours of support, the serum bicarbonate at 24 hours of support, the urine output over the first 24 hours of support, and the development of renal failure to have a statistically significant association with survival in children supported with extracorporeal membrane oxygenation. None of the clinical parameters evaluated by univariate analysis were significantly associated with survival in the patients supported with ventricular assist devices. CONCLUSIONS: Extracorporeal membrane oxygenation and ventricular assist devices represent complementary modalities of mechanical circulatory support that can both be used effectively in children with cardiac disease.

Child↗
PubMed1999

Echocardiographic assessment of interrupted aortic arch.

BACKGROUND: In patients with interrupted aortic arch echocardiography provides detailed information about the anatomy of the aortic arch and the associated cardiac anomalies. Only a few reports have evaluated the reliability of this non-invasive diagnostic procedure by correlation with angiographic and surgical findings. METHODS: From 1988 through 1993, 45 infants with interrupted arch underwent surgical repair (mean age 13.02 days). Of the patients, 33 had interruption of the arch between the left common carotid and subclavian arteries; 25 patients had a ventricular septal defect, and the remaining 20 had coexisting complex congenital heart defects. Preoperative diagnosis was made exclusively by echocardiography in 25 of the patients. Accuracy of echocardiographic diagnosis was evaluated retrospectively by comparing preoperative studies with angiography and surgical reports. We then investigated whether the morphologic features of the interrupted arch might influence surgical procedure or outcome. RESULTS: Intracardiac anatomy was accurately diagnosed by echocardiography in all cases; in 2 patients angiography provided additional information concerning the morphology of the aortic arch. Operative notes described differences in morphology of the arch in 7 patients, but these did not influence the surgical procedure. Direct anastomosis of the interrupted segments was possible in 38 patients, and 36 patients underwent primary intracardiac repair. Echocardiographic measurements revealed that the diameter of the ascending aorta was related to the number of vessels originating from the proximal aortic arch. The distance between the interrupted segments was significantly different according to the site of interruption, but not between cases with an isolated ventricular septal defect versus those with complex heart disease. It did not influence the method of arch repair, nor was it related to recurrent or residual obstruction. CONCLUSION: Preoperative echocardiography offers accurate and complete diagnosis in the critically ill neonate with interrupted aortic arch and associated intracardiac abnormalities.

Aorta, Thoracic↗
PubMed1999

The effect of hematocrit on cerebral blood flow velocity in neonates and infants undergoing deep hypothermic cardiopulmonary bypass.

UNLABELLED: Varying degrees of hemodilution are used during deep hypothermic cardiopulmonary bypass. However, the optimal hematocrit (Hct) level to ensure adequate oxygen delivery without impairing microcirculatory flow is not known. In this prospective, randomized study, cerebral blood flow velocity in the middle cerebral artery was measured using transcranial Doppler sonography in 35 neonates and infants undergoing surgery with deep hypothermic cardiopulmonary bypass. Patients were randomized to low Hct (aiming for 20%) or high Hct (aiming for 30%) during cooling on cardiopulmonary bypass (CPB). Systolic (V(s)), mean (Vm), and diastolic (Vd) cerebral blood flow velocity, as well as pulsatility index (PI = [V(s) - Vd]/Vm) and resistance index (RI = [V(s) - Vd]/V(s)) were recorded at six time points: postinduction, at cannulation, after 10 min cooling on CPB, rewarmed to 35 degrees C on CPB, immediately off CPB, and at skin closure. Vm was significantly lower in the high Hct group compared with that in the low Hct group during cooling (P < 0.01). Postinduction, the high Hct group demonstrated significantly lower Vd immediately off CPB (P < 0.01) and significantly lower Vm and V(s) at skin closure (P < 0.001). We conclude that there is an inverse relation between hematocrit and cerebral blood flow velocity during deep hypothermic cardiopulmonary bypass in neonates and infants. IMPLICATIONS: There is an inverse relation between hematocrit and cerebral blood flow velocity during deep hypothermic cardiopulmonary bypass in neonates and infants. Further studies correlating Hct and cerebral blood flow velocity with cerebral metabolic rate and neurologic outcome are necessary to determine the optimal Hct during deep hypothermic cardiopulmonary bypass.

Blood Flow Velocity↗
PubMed1998

Relation of seizures after cardiac surgery in early infancy to neurodevelopmental outcome. Boston Circulatory Arrest Study Group.

BACKGROUND: The outcome of infants who have transient seizures after open heart surgery has not been studied. Using the database of the Boston Circulatory Arrest Study involving 171 children with D-transposition of the great arteries, we explored the relationship between early postoperative clinical and EEG seizures and neurodevelopmental outcomes at ages 1 and 2 1/2 years. METHODS AND RESULTS: At 1 year, children returned for developmental and neurological evaluations and MRI. Parent-completed developmental questionnaires were collected at 2 1/2 years of age. At 1 year, children with early postoperative seizures had lower Psychomotor Development Index (motor function) scores (clinical seizures: 12.9 mean difference [MD]; 95% confidence interval [CI], 2.2 to 23.6; P=.02; EEG seizures: 13.3 MD; 95% CI, 6.8 to 19.7; P<.001). Mental Developmental Index scores of children with clinical or EEG seizures were also lower, but the differences were not statistically significant. Infants with seizures were more likely to have an abnormal neurological examination (clinical seizures: 78% versus 31%; P=.008; EEG seizures: 58% versus 34%; P=.04). Children with EEG seizures were more likely to have MRI abnormalities (43% versus 13%, P=.002). At age 2 1/2, children with EEG seizures had lower scores in several areas of function. CONCLUSIONS: In infants undergoing the arterial switch operation for correction of D-transposition of the great arteries, transient postoperative clinical and EEG seizures were associated with worse neurodevelopmental outcomes at ages 1 and 2 1/2 years as well as neurological and MRI abnormalities at 1 year of age. The occurrence of such seizures may provide an early sign of brain injury with neurological and developmental sequelae.

Age Factors↗
PubMed1998

Accuracy of echocardiography for detection of aortic arch obstruction after stage I Norwood procedure.

BACKGROUND: Echocardiography has been widely used in postoperative assessment after stage I Norwood procedure, but its accuracy in detecting aortic arch obstruction (AAO) has not been determined. This study was designed to determine the accuracy of echocardiography in the diagnosis of AAO after stage I Norwood procedure, identify echocardiographic predictors of arch obstruction, and examine the time course of its development. METHODS: The records and echocardiography reports of 139 patients who survived stage I Norwood procedure were reviewed. Reference standard for the diagnosis of AAO was catheterization, surgery, or autopsy. RESULTS: AAO was diagnosed by reference standard criteria in 31 (22%) patients. Echocardiography correctly diagnosed AAO in 19 patients, missed the diagnosis in five, and wrongly predicted AAO in eight, yielding a 73% sensitivity, 92% specificity, 70% positive predictive value, and 88% accuracy. Moderate or severe right ventricular dysfunction, moderate or severe tricuspid regurgitation, and an abnormal abdominal aortic Doppler flow pattern were more common in patients with AAO. The probability of AAO developing within 6 months after stage I Norwood procedure was 21.1%, with a very small likelihood after that point. Beyond the first 30 days after surgery, the risk of death was higher in patients in whom AAO developed compared with those in whom it did not (relative risk 5.9, 95% confidence interval 2.7 to 13.2). CONCLUSIONS: Echocardiography is a highly specific modality in detecting AAO after stage I Norwood procedure but its sensitivity is limited. Because of the increased risk of death associated with AAO and because most obstructions develop between 1 and 6 months postoperatively, early cardiac catheterization with possible intervention should be considered in patients with moderate or severe right ventricular dysfunction, moderate or sever tricuspid regurgitation, or an abnormal abdominal Doppler flow pattern during that period.

Aortic Arch Syndromes↗
PubMed1998

Effects of oncotic pressure and hematocrit on outcome after hypothermic circulatory arrest.

BACKGROUND: A recent study found that a higher-perfusate hematocrit was associated with improved neurologic recovery after deep hypothermic circulatory arrest. The current study examined the relative contributions of oxygen delivery and colloid oncotic pressure to this result, as well as the efficacy of different colloidal agents and modified ultrafiltration. METHODS: Twenty-six piglets were randomized into five groups (n = 5 or 6 animals per group): control group 1--blood and crystalloid prime, hematocrit of 20%; group 2--blood and hetastarch prime, hematocrit of 20%; group 3--blood and pentafraction prime, hematocrit of 20%; group 4--blood and crystalloid prime with 10 minutes of modified ultrafiltration; group 5--whole blood prime, hematocrit of 30%. All groups underwent 60 minutes of deep hypothermic circulatory arrest at 15 degrees C. RESULTS: Groups 2 and 3 showed less body weight gain (analysis of variance, p = 0.001; group 2 versus group 1, p = 0.0009; group 3 versus group 1, p = 0.0009) and body water content after cardiopulmonary bypass (analysis of variance, p = 0.001; group 2 versus group 1, p = 0.003; group 3 versus group 1, p = 0.013). Group 5 showed more rapid recovery of phosphocreatine and intracellular acidosis, as measured by magnetic resonance spectroscopy, during rewarming than group 1 did (phosphocreatine, p = 0.0329; intracellular acidosis, p = 0.0462). Group 3 also showed accelerated recovery of intracellular acidosis (p = 0.0411). Cytochrome a,a3 recovery, determined by near-infrared spectroscopy, was significantly better in group 5 than in group 1 and worse in group 2 than in group 1 after rewarming. The neurologic deficit score and overall performance category score were best in group 5 (neurologic deficit score, p = 0.012; overall performance category score, p = 0.046) on the first postoperative day. Group 3 also had a better overall performance category score than group 1 did (p = 0.0068). Only group 1 and 2 animals showed histologic damage. CONCLUSIONS: Both higher hematocrit and higher colloid oncotic pressure with pentafraction improve cerebral recovery after deep hypothermic circulatory arrest. The higher hematocrit improves cerebral oxygen delivery but does not reduce total body edema. Modified ultrafiltration after cardiopulmonary bypass is less effective than having a higher initial prime hematocrit or colloid oncotic pressure.

Animals↗
PubMed1998

Postischemic hyperthermia exacerbates neurologic injury after deep hypothermic circulatory arrest.

BACKGROUND: Aggressive surface warming is a common practice in the pediatric intensive care unit. However, recent rodent data emphasize the protective effect of mild (2 degrees - 3 degrees C) hypothermia after cerebral ischemia. This study evaluates different temperature regulation strategies after deep hypothermic circulatory arrest with a survival piglet model. METHODS: Fifteen piglets were randomly assigned to 3 groups. All groups underwent 100 minutes of deep hypothermic circulatory arrest at 15 degrees C. Brain temperature was maintained at 34 degrees C for 24 hours after cardiopulmonary bypass in group I, 37 degrees C in group II, and 40 degrees C in group III. Neurobehavioral recovery was evaluated daily for 3 days after extubation by neurologic deficit score (0, normal; 500, brain death) and overall performance category (1, normal; 5, brain death). Histologic examination was assessed for hypoxic-ischemic injury (0, normal; 5, necrosis) in a blinded fashion. RESULTS: All results are expressed as mean +/- standard deviation. Recovery of neurologic deficit score (12.0 +/- 17.8, 47.0 +/- 49.95, 191.0 +/- 179.83; P = .05 for group I vs III), overall performance category (1.0 +/- 0.0, 1.4 +/- 0.6, 2.8 +/- 1.3; P < .05 for group I vs III), and histologic scores (0.0 +/- 0.0, 1.0 +/- 1.2, 2.8 +/- 1.8; P < .05 for group I vs III cortex) were significantly worse in hyperthermic group III. These findings were associated with a significantly lower cytochrome aa3 recovery determined by near-infrared spectroscopy in group III animals (P = .0041 for group I vs III). No animal recovered to baseline electroencephalographic value by 48 hours after deep hypothermic circulatory arrest. Recovery was significantly delayed in the hyperthermic group III animals, with a lower amplitude 14 hours after the operation, which gradually increased with time (P < .05 for group III vs groups I and II). CONCLUSIONS: Mild postischemic hyperthermia significantly exacerbates functional and structural neurologic injury after deep hypothermic circulatory arrest and should therefore be avoided.

Animals↗
PubMed1998

Use of rapid-deployment extracorporeal membrane oxygenation for the resuscitation of pediatric patients with heart disease after cardiac arrest.

INTRODUCTION: We have recently used extracorporeal membrane oxygenation as a means of rapidly resuscitating pediatric patients with heart disease after cardiopulmonary arrest, in whom conventional resuscitation measures have failed. METHODS: We developed a fully portable extracorporeal membrane oxygenation circuit that is maintained vacuum and carbon dioxide-primed at all times. When needed, the circuit is crystalloid-primed and can be ready for use within 15 minutes. Since February 1996, we have used this rapid-deployment circuit to resuscitate 11 pediatric patients in full cardiopulmonary arrest. RESULTS: The median age of the 11 patients was 120 days (2 days to 4.6 years). Nine patients had a cardiac arrest after cardiac surgery. One patient had a cardiac arrest during cardiac catheterization and one patient had a cardiac arrest before cardiac surgery. Median duration of cardiopulmonary resuscitation was 55 minutes (range 20 to 103 minutes), with no difference in the duration of cardiopulmonary resuscitation between survivors and nonsurvivors. Ten of 11 patients (91%) were weaned from extracorporeal membrane oxygenation and seven (64%) survived to hospital discharge. Six patients are long-term survivors, five of whom are in New York Heart Association class I; one survivor is in class II. Seven patients resuscitated with extracorporeal membrane oxygenation before the use of this rapid-deployment circuit had a median duration of cardiopulmonary resuscitation of 90 minutes, with two (28.6%) survivors. CONCLUSIONS: The use of rapid-deployment extracorporeal membrane oxygenation results in shorter resuscitation times and improved survival in pediatric patients with heart disease after cardiopulmonary arrest.

Cardiac Surgical Procedures↗