piculecarf

7/29/2019 piculecarf

1/72

RESPIRATORY FAILURE

(ACUTE)

Dora M Alvarez MD

LH 2004


2/72

Acute RF

Definitions - Physiology

Assessment - clinical picture

Case Studies Indications for Intubation.

Respiratory Support


3/72

Definitions

Acute Respiratory Failure: Any disruption in

the function of the respiratory system

Respiratory Function:

DELIVER ADEQUATE OXYGEN TO

OR

REMOVING CARBON DIOXIDE FROM

THE PULMONARY CAPILLARY BED

OR BOTH


4/72

Many causes

Respiratory Failure Shock

( Survival 75%-90%)

Death

Cardiovascular

recovery

Cardiopulmonary Failure(Survival 7% -11%)

Neurological impairment Neur..recovery


5/72

The Assessment of

Respiratory Function

Gas Exchange

O2

CO2ABGVBG ?


6/72

VBG? ABG

Ph 7.35CO2 45

O2 45O2

Ph 7.4CO2 40

O2 90-100

CO2


7/72

PaCO2 = VC02/ MVV

Pa CO2: partial pressure of arterial CO2

VC02: CO2 production

MVV: Minute Volume Ventilation

MVV = TV x RR PaCo2

CO2O2

Gas Exchange


8/72

MVV = TV x RR

TV = 6 -7 ml/kg

RR = 12 bpm (> 15 yo- Adult)

50 Kg Adolescent / Adult

TV RR MVV PaCO2

300 l 12 3600 l Nor al

N

NN

N


9/72

Gas Exchange

CO2Pa O2

Pulse -Oxymetry: Measure light absorption

Falsely High ..... CO (has high affinity for Hb and

has the similar light absorption

Falsely Low ..MetaHeb

(Hemoglobinopathies: ie Sickle Cell disease 2nd to

abnormal OxyHb affinity

CO oximetry: uses more different wave light

absorption. ABG (cBG) /


10/72

The alveolar-arterial oxygen (A-a)

(A-a) gradient is a useful measure of the

efficiency of oxygenation.

It compares the diffusion of oxygen from

the patient's alveoli to his or her pulmonary

capillaries with diffusion in an idealized

model of the lung without

ventilation/perfusion inequalities or cyclicalvariations in ventilation or circulation.


11/72

A-a Gradient

Calculation of this value incorporates a

measure of alveolar ventilation (alveolar

CO2, approximated as arterial CO2),therefore it is unaffected by hyper- or

hypoventilation.


12/72

The A-a gradient can be calculated

from the following formula:

A-a gradient = FiO2 x (pAtm-pH2O) - (paCO2/R) +

[paCO2 x FiO2 x (1-R)/R] - paO2,

where pAtm = 760 mmHg x exp ( -altitude in

meters/7000 ) [3],

and pH2O = 47 mmHg x exp ( (Temperature incentigrade-37)/18.4 ) [4].


13/72

Arterial pCO2 in mmHg: 40

Arterial pO2 in mmHg: 90

Percent of inspired O2 (%): 21

(Fraction of inspired O2: 0.21 )

Respiratory quotient: 0.8

Patient's temperature inF: 98.6(or inC: 37.0 )

Approximate elevation in feet:0(or in meters: 0 )

A-a gradient in mmHg: 10


14/72

Normal A-a gradient values have not

been well established, but

Tend to increase with age Are slightly higher on 100 percent

oxygen than on room air.


15/72

ARF

In the absence of intra-cardiac shunt.

Pa02 < 50 mm hg

PC02 > 50 mmHg Increase a-a gradient (>300)

Increase Pao2/Fio2 < 200 (normal >400)

(Pao2 60 on fio2 of 0.6 = 100)


16/72

Respiratory Assessment1. Mental Status (Is patient being sedated)

2. RR (according to age)

3. Work of breathing (retraction, nasal flaring,paradoxic breathing)

4. Chest movement-Air-entry5. Adventitious sounds (Stridor-wheezes,

crackles)

6. Oxygen requirements

7. Cardiovascular status, (Compensatorymechanisms: HR, BP, perfusion)

8. Peak Flow

9. ABG


17/72

Respiratory Assessment

Is the patient Ventilating well? >> Normal PCO2

Normal ventilatory effort

Increase work of breathing

Able to compensate Is patient getting exhausted >> Impending respiratory

failure

Is the patient oxygenating well? >> Normal Pa O2

Assess oxygen requirement A-a gradient Vs PaO2/FiO2 >> Hypoxic respiratory

failure?


18/72

Respiratory Center and Upper

AirwayCNS depression

Trauma

Infection

Drug OD

Nasal

Obstruction:URI-FB-

Congenital

Nasopharyngeal AreaCongenital Cleft Palate

Adenoids

Oropharyngeal AreaTonsilsRPA-FB

Larynx:

Epiglottitis

Croup syndrome


19/72

Intra-thoraxic/

Extrapulmonary Airway

- wheezing, Inspi. and Exp

Intraluminal

Wall

Extrinsic compression

Intrathoracic/

Intrapulmonary

- Wheezing Expiratory Intraluminal

Wall

Extrinsic

compression


20/72

Chest Wall

Flail (compliance) Chest Trauma

Hypotonia (GB)

Stiff (compliance)

Burns

Alveolar (Alveolar

filling process) Pneumonia

Pulmonary Edema

Hemorrhages


21/72

Case 115 mo. Old, admitted to PICU with dx of

croup, mild respiratory distress.

Previously healthy

2 days hx of URI with low grade fever, increasing

barking cough, tachypnea decrease PO intake

Monday 5PM

Alert, vigorous cry, barking cough, persistent stridor

during sleep, increases with crying:VS: 100.2 F, RR 30 O2 sat, 96 % RA,

PE, Lung: fair air entry; inspiratory stridor when crying

Studies:


22/72


23/72

5 PM

Increase Respiratory

distress

Persistent stridor

Increased retractions.

O2 Sats in RA 90 %

Rx:

Humidified Oxygen:

Mode of deliver?

How much?,

Percentage of O2

NPO, IV fluid

Meds:

Racemic epi, Decadron


24/72

Oxygen Delivery Systems

Low Flow:

Nasal Cannula:

no more than 5L/min

Each L/min delivers ~ 4 % Oxygen > RA

At low flows, no need to humidify

Simple Mask

Use for an emergency / transport

Deliver ~ 30% at 6-8 L/min


25/72

O2 Flow each L/min Flow increases the inspired FiO2

by ~ 4 %(over the 21 % Room Air FiO2 at sea level)

1 L/min 24 %

2 L/min 28 %

3 L/min 31 %

4 L/min 35 %

5 L/min 38 %

DO NOT GO HIGHER THAN 5 L/MIN; especially if no humidified

oxygen is being use it may cause Nose bleeding.

NASAL CANNULA


26/72

Simple mask (low flow system)Can deliver up to 40 - 60 % FiO2 (at Flow 6 to 10 L/min)

O2 Flow ~ FiO2 being delivered

6 L/min 40 %

7 L/min 44 %

8 L/min 50 %

9 L/min 55 %

10 L/min 60 %


27/72

Oxygen Delivery Systems

Middle Flow: > 35 % < 50 %

Simple Mask

Use for an emergency / transport

Deliver ~ 30% at 6-8 L/min

Venturi (Venti-Mask)

Color attachment determines the Oxygen deliver

From 25 % to 50 %

At low flows, no need to humidify


28/72

Venturi Mask: uses the venturi system,

mixing different flows of 100% Fi02 with room air in

different color adaptors:

O2 Flow Color Adaptor ~ FiO2 being

delivered

4 L/min Blue 24 %

5 L/min Yellow 28 %

6 L/min White 31 %

7 L/min Green 35 %

8 L/min Pink 40 %

10 L/min Orange 50 %


29/72

Aerosol / humidified mask (can be adjusted to deliver 21

to 100 % FiO2 and it is the preferredmethod to deliveroxygen in the PICU, because we can easily follow the trend

of the patients oxygen requirements.

Non rebreeding mask (high flow delivered system with

reservoir, it deliver between 80 to 100% FiO2.

This deliveringSystem is use mainly for transport and forinitially emergency care and patient stabilization.

HIGH FLOW OXYGEN


30/72

OTHERS

Oxyhood

Humidified

21% to 100 %Variable

Croupette / Tent


31/72

11:30 PM

Suddenly Increase coughing

spell with worsening stridor,

severe respiratory distress,


32/72

Rx: Extra Vapo, no improvement- Hypoactive, pale, diaphoretic

- Saturation 75 % on oxygen by

mask

- HR 180


33/72

- Intubation with a smaller ET

tube than indicated for age and

size.- Keep it well sedated

- Continue steroids x 24 hours

- Look for signs of aspiration.


34/72

CROUP SYNDROME

UAOStridor

(Laryngeal Obstruction)

Viral Croup Spasmodic croup (Hyperreactive UAW)

Epiglottitis

Laryngomalacia FB


35/72

Febrile, Toxic looking, drooling,


36/72

Urgent/ Semi elective intubation done in the OR


37/72

Case 25 yo s/p T&A for OSAS admitted to

PICU for observation.

Friday 2 PM

Awake crying, clear voice, Breathing comfortable, (mouth breathing)

Afebrile

Sat. 98% RA Lung, good air entry

Hemodynamically stable, IV in place


38/72

Rx:

- Clear fluids ( T&A diet)

- IV fluids- Humidified O2/Air as tolerated

- Pain meds.


39/72

10 PM

- Sleeping with loud snore, severe

retractions, O2 Sat 70 %.

HR 140 Try to wake him, unable.

Given oxygen, O2 sat increased to 80 %.


40/72

Post Op complication of

T&A for OSAS

Residual Obstruction 2nd to

nasopharyngeal tissue swelling. (Uvula)

Collapsable nasopharynx (patient oversedated)

Respiratory depression 2nd to painmedication

Post release of Obstruction Pulmonary

Edema Hemorrhage


41/72

Rx:

Reverse drug effect if narcoticoversedation.

Nasopharyngeal Airway

Bi-Pap

Back to OR if significant bleeding. Intubation


42/72

Case 310 yo MVA with head trauma, LOC -

Concussion, Normal head CT. Admitted to

PICU for observation. Previously healthy

Saturday 10 PM Alert, oriented x 3, GCS 15

C-R stable, no other injuries

Rx:

NPO, IV Fluids


43/72

Sunday 8 AM

- Vomited a few times

- Sleeping

- RR, unlabored 15 / min

- O2 Sats 90 % RA

- Lungs clear to auscultation- HR 80/ min


44/72

PE:

- Difficult to arouse

- Pupils sluggish reactive


45/72

Rx:

- Open airway

- O2- Intubate / Mannitol

- Repeat Head CT

- Call Neurosurgery team?


46/72

Early sign of herniation

Decrease Mental status

Respiratory depression >> upper airway

obstruction >>>> Desaturations

Sluggish pupillary reaction

Triad:Alter mental status- Bradycardia

Hypertension


47/72

Patient at risk of herniation

CNS Trauma. HEAD CT CAN BE NORMAL

CNS Infections

DKA Severe hyponatremia / hypernatremia

dehydration.


48/72

Case # 45 yo with status asthmaticus in severe

respiratory distress.

Sunday 6 PM

- Awake, irritable in severe respiratory distress- RR 60

- Severe retractions, with nasal flaring

- O2 Sat when receiving Nebs. 90%

- HR 180


49/72

Rx:

- Oxygen (with Nebs)

- Continuously (back to back) Nebs

treatments- IV Solu-Medrol

- NPO

- IV Fluids- Studies: >>


50/72

ABG when on Nebulizer

Ph:7.25

PCO2:49

PO2:100 Sat: 98%Bic15

BE-10

CxR

Hyperinflation only


51/72

Complication in CxR in

patient with LAO

Pneumomediastinum

Lobar collapse

Pneumothorax


52/72


53/72


54/72


55/72


56/72


57/72

Case # 5

6 yo with severe muscle weakness

2nd to GB

Monday 12 noon

- Alert, oriented, unable to sit up with outhelp

- RR 18 O2 Sat 100 % RA

- Talking with a good tone of voice- Fair to Good cough and gag effort

- Lung: good air entry


58/72

Rx:

- CR monitoring- IV in place

- IVGG order- Clear fluids

- Bed side PFT:

NIP (Negative Insp. Pressure

MVV)


59/72

Tuesday 7 AM

- Patient seems irritable,uncomfortable- RR 18 unlabored

- O2 Sats. 90 % in RA

- Lungs clear


60/72

-Poor cough effort- voice softer

Studies:


61/72

ABG on oxygen:

Ph7.15

PC02:60P02:60

02 Sat80%

Bic:20

BE:-2


62/72

Patients with Neuromuscular

dysfunction do not show

respiratory distress

Case # 6


63/72

Case # 6

7 yo with ACS, bilateral infiltrates

in moderate respiratory distressFriday 4 PM

Alert, uncomfortable, sick looking

RR 60, mild SC retraction, flaring andgranting.

O2 100 % on non-rebreathing mask

Lungs. Decrease breath sounds over thewhole left lung, crackles and bronchophony

Studies:


64/72

ABG P ti l R b thi


65/72

ABG on Partial Rebreathing

mask (>80%)

Ph 7.47

PCO2 30

PaO2 100

O2 Sat: 98 %

Bic 25

BE -2


66/72

A-a gradient(N


67/72

CBC

WBC 21 K

H/H 6 / 19

Plat. 250


68/72

Rx

NPO

IV Fluid

Transfusion / exchange transfusion BI-PAP >>> Intubation


69/72

HYPOXIC RESPIRATORY FAILURE

1. Pa O2 < 60 (O2 Sat < 85%)on FiO2 > 60 %

2. Increase A-a Gradient > 300

3. Decrease PaO2 / FiO2 < 150


70/72

Rx

NPO

IV Fluid

Transfusion / exchange transfusion BI-PAP >>> Intubation


71/72

HYPOXIC RESPIRATORY FAILURE

1. Pa O2 < 60 (O2 Sat < 85%)on FiO2 > 60 %

2. Increase A-a Gradient > 300

3. Decrease PaO2 / FiO2 < 150


72/72

Buddy

piculecarf

Documents