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Minimal monitoring standards for children a pediatric cardiac ICU include: 1.ECG, arterial line, CVP. 2.Central and peripheral temperature. 3.Pulse oximetry, temporary pacing wires. 4.Typically a left atrial line. 5.Pulmonary artery catheters The monitoring requires a 1:1 nurse:patient.
POSTOPERATIVE CARE OF THE PATIENTS WITH TOF BACKGROUND: Minimal monitoring standards for children a pediatric cardiac ICU include: 1.ECG, arterial line, CVP 2.Central and peripheral temperature 3.Pulse oximetry, temporary pacing wires 4.Typically a left atrial line 5.Pulmonary artery catheters The monitoring requires a 1:1 nurse:patient BACKGROUND (CONTINUE): Post-op care of patients with TOF is typically uneventful with most patients being extubated within 24 hours of surgery Patients with TOF increase their interstitial, pleural, and peritoneal fluids early postoperatively Like other cyanotic individuals, they can be sensitive to the damaging effects of CPB THE DAMAGING EFFECTS OF CPB: ( BACKGROUND ) Vascular access: ♦Monitoring of arterial blood pressure and intermittent blood gas by arterial cannulae Retention and bleeding: ♦ Checking coagulation times and platelet count ♦ Bleeding into the pericardium results in the pericardial tamponade So, an ECHO should be obtained soon after line removal Two common causes of cardiac tamponade: 1.The presence of blood 2.Compression of the heart by adjacent structures ♦ Cardiac tamponade: gradual onset of hypotension, elevated heart rate, left atrial and CVP and reduction in CO and hence pulse volume with inspiration(pulsus paradoxus) Nutrition: ( CPB continue) ♦The goals of metabolic and nutritional support in the paediatric cardiac ICU are first ♦ Allowance must be made in planning postop feeding, to provide sufficient calories for ongoing needs and “catch-up” requirement Age (years) Weight (kg) Caloric requirement (kcal/kg) 1-6 7-12 12-18 3-10 11-20 21-40 40-70 90-120 75-90 60-75 25-30 I.REPAIR: 1.Residual hemodynamic problems: * Residual VSD *RV outflow tract obstruction *PV and/or annular stenosis *Supravalvar PA stenosis *PR *TR *RV dysfunction *RV outflow tract aneurysm *LV dysfunction *PHTN 2.Arrhythmia and conduction disturbance: *SVT *VT *Complete heart block REPAIR:(continue) Assessing of the hemodynamic continuously Measurement of cardiac output Identifying of an important right-to-left or left-to-right shunt by ECHO Following arterial desaturation in the early hours after operation (Desaturation from right-to-left shunting usually decreases within 48 hours as RV function improves) In the absence of shunt, values of PLA and PRA relate the function of ventricular (After repair, these are usually similar) If PLA is to 10mmHg higher than P RA, a residual left-toright shunt at ventricular or great artery sought promptly closed by reoperation If no shunt, elevated PLA indicates LV hypoplasia or severe impairment of LV systolic or diastolic function (inotropic agent and afterload reduction) REPAIR : (continue) PRA is rarely to 10 mmHg higher than PLAindicating important volume or pressure overload of the RV or RV dysfunction (Precarious) PRA /PLA is greater than 0.7, the patient should reoperate (if a transannular patch was not used) If a transannular patch is in place, catecholamine is indicated Bleeding (Preoperative polycythemia and depletion of many clotting factors, extensive collateral circulation, and damaging effects of CPB tendency to bleed (platelet-rich-plasma and reoperated) Residual VSD: ( REPAIR : continue.) Residual VSD may be poorly tolerated: ►The normal LV pre-op without significant ventricular hypertrophy ► Present early postoperatively of congestive HF ► Cardiac catheterization Most residual VSDs are small and important only in terms of the potential for infective endocarditis If hemodynamic instability occur after repair, the present of residual VSD should be promptly and thorough investigated REPAIR: (continue) After the patients leave the ICU, body weight is followed closely (Transient fluid retention is common) Digoxin is useful in a volume overload RV for weeks Diuretics are used as indicated REPAIR: (continue) Residual right ventricular outflow tract obstruction ( RRVOTO): Residual narrowing in the infundibulum, at the RV pulmonary trunk junction ( with or without a transannular patch) or more distally Stiffening, thickening, and eventually even calcification of PV cusps cause RV hypertention RRVOTO occurred uncommonly, lately It includes: valvar stenosis, annular stenosis, and supravalvar main pulmonary arterial obstruction The site and severity of them determined by ECHO Balloon valvuloplasty or reoperate RRVOTO (continue): Pulmonary artery branch stenosis is relatively common post-op The left pulmonary artery at the site of prior ductus insertion It can be treated by using transcatheter balloon arterioplasty with or without the use of stents REPAIR: (continue) Right ventricular dysfunction: RV systolic hypertention and PR after repair RV systolic function and end-diastolic volumn Post-op RV systolic and diastolic function and a resting systolic pressure up to 60 to 70 mmHg have little adverse effect Higher systolic pressures produce dysfunction Low CO may be attributable to RV dysfunction (Elevated CVP hepatomegaly, edema, pleural effusion…) RV dysfunction assessed by ventricular size and EF and severe PR (3 to days to recover) The mainstays of therapy are inotropic support, digoxin, diuretics and ventilatory maneuvers to decrease the P vascular resistance can reduce RV afterload Negative pressure ventilation improve CO well to avoid secondary organ damage TR usually occurs with moderate to severe right ventricular dilatation secondary to PR and/or right ventricular dysfunction When operation is required for P V replacement or correction of residual outflow obstruction, TV annuloplasty can be a useful adjunctive procedure REPAIR: (continue) PR commonly accompanies TOF repair b/c of the frequent need for transannular patching for adequate relief of right ventricular outflow tract obstruction PR is usually well tolerated when PA and RV pressures are low REPAIR:(continue) Right ventricular aneurysms: Prominent outflow patches were too large to begin with The aneurysms may be a false one ( true aneurysms as usual) excessive thinning or devascularization of the RV free wall or thinning and bulging of pericardium if it has been used as an infundibular or transannular patch Most RV aneurysms develop within months of operation, and true ones stabilize and rarely progress, whereas false ones may progress rapidly and rupture These patches are akinetic, can contribute to RV dysfunction They should be resected and retailored Only 0.9% of patients of TOF underwent reoperation for RV aneurysms REPAIR: (continue) LV ventricular function: 1.LV systolic and diastolic function are variable late post-op 2.Risk factors for poor LV function include: ►Older age at repair, ► Pre-repair status of LV ► Residual or recurrent defects Infective endocarditis: it is rare after repair REPAIR:(continue) Arrhythmia and conduction disturbance: Arrhythmia death was 5% to 10% when the patients underwent repair in adult life While it occur 1% of the patients younger than age years at operation The RV scar may be arrhythmogenic Excising the scar and inserting a patch graft Heart block: Complete heart block is common after repair It occurred in 1,3% Junctional ectopic tachycardia: It occurs infrequently after repair of TOF Survival depends on aggressive treatment in ICU with core cooling and amiodaron Thereafter, there is probably little risk of complete heart block II.SYSTEMIC-PULMONARY ARTERIAL SHUNTING: Careful intraoperative monitoring and control of PaO2, pH, and buffer base are required An intraarterial needle may have been placed preoperatively, and the baby is returned to the ICU still intubated Using dopamine and epinephrine to establish arterial blood pressure is 10% to 20% greater than normal to ensure good flow through the shunt Recommending a heparin drip for 24 hours A chest radiograph is obtained after procedure and every hours later Hemorrhagic pulmonary edema produces hypoxia and clinical deterioration So, many patients died a few days after shunting operations for TOF SYSTEMIC-PULMONARY ARTERIAL SHUNTING: Mild renal failure, rarely acute renal failure and anuria develop after a simple shunting procedure A surgically created shunt must function If is poorly functioning, prompt reoperation is indicated So, auscultation ( excepting large AP collateral arteries, a continuous murmur is present pre-operatively) for assessing its patency during the entire post-op If cyanosis has not improved, ECHO or aortography is indicated a hospital mortality approaching zero Even in the first month of life, hospital mortality was 0.6% SYSTEMIC-PULMONARY ARTERIAL SHUNTING: The most important risk factor for early death after classic shunting procedures is PA problems and young age Early (less than 30 days) nonfatal shunt closure or narrowing occurs uncommonly (7%) in patients undergoing classic B-T or PTEE shunt operations Intermediate-term shunt closure or narrowing requiring reoperation is more common in neonates and young infants than older patients occuring in 3% to 20% Reduced blood flow in the arm on the side of a classic B-T shunt Severe blood flow reduction cause gangrene of the hand occur Sudden death, without explanation or autopsy is common after classic shunting procedures (4 months after operation) Nonfatal brain absess is also common Iatrogenic PA problems:Angiographic evidence of PA distortion is fairy common late post-op Beneficial interim results of shunting procedures are increased Qp, with consequent reduction in cyanosis and polycythemia, and improved functional capacity SYSTEMIC-PULMONARY ARTERIAL SHUNTING: NYHA functional class is usually I or II after shunting SaO2 at rest is about 80% to 90%, but always decrease with exercise, at times to as low as 50% These benefits are obtained at the expense of increased LV stroke volumn, a stimulus to gradual development of LV dysfunction Diffuse increase in size of the RPA and LPA Severe infundibular or valvar stenoses becomes complete atresia after a palliative shunting operation Important pulmonary vascular disease may develop after a classic B-T shunt but rarely before years The proportion of patients developing hypertention pulmonary vascular disease increases with increasing shunt duration (before years) ... nurse:patient BACKGROUND (CONTINUE): Post- op care of patients with TOF is typically uneventful with most patients being extubated within 24 hours of surgery Patients with TOF increase their interstitial,... retailored Only 0.9% of patients of TOF underwent reoperation for RV aneurysms REPAIR: (continue) LV ventricular function: 1.LV systolic and diastolic function are variable late post- op 2.Risk factors... severity of them determined by ECHO Balloon valvuloplasty or reoperate RRVOTO (continue): Pulmonary artery branch stenosis is relatively common post- op The left pulmonary artery at the site of