POSTOPERATIVE CARE OF THE PATIENTS WITH TOF, CHĂM SÓC BỆNH NHÂN TỨ CHỨNG FALLOT SAU PHẪU THUẬT

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.

 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:

 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

post-op feeding, to provide sufficient calories for

ongoing needs and “catch-up” requirement.

Age (years)

Weight (kg)

Caloric requirement (kcal/kg)

< 1

>1-6 7-12 12-18

3-10 11-20 21-40 40-70

90-120 75-90 60-75 25-30

1.Residual hemodynamic problems:

* Residual VSD

*RV outflow tract obstruction.

*PV and/or annular stenosis.

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 2 ventricular (After repair, these are usually similar)

If PLA is 5 to 10mmHg higher than PRA, a residual

left-to-right 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 5 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 6 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 5 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.

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 6 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.

Arrhythmia and conduction disturbance:

underwent repair in adult life.

years at operation

and inserting a patch graft.

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 4 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:

anuria develop after a simple shunting procedure

indicated So, auscultation ( excepting large AP

collateral arteries, a continuous murmur is

present pre-operatively) for assessing its patency during the entire post-op

aortography is indicated.

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

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 7 years

The proportion of patients developing hypertention pulmonary vascular disease increases with increasing shunt duration

(before 5 years)