tissue hypoxia and oxygen therapy - prince of songkla...

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Tissue Hypoxia and Oxygen Therapy 1. 2. 3. tissue hypoxia 4. 5. 6. 7. tissue hypoxia 1. Pathway of oxygen transport 2. Causes of tissue hypoxia 3. Effect of oxygen administration 4. Oxygen devices with spontaneous breathing 5. Selection of patient for oxygen devices with spontaneous breathing 6. Effects of inadequate humidification of inspired gases 7. Humidifier and nebulizer 8. Evaluation of oxygen therapy 9. Oxygen hazard 21%

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Page 1: Tissue Hypoxia and Oxygen Therapy - Prince of Songkla ...medinfo2.psu.ac.th/surgery/Edu_be_document/document4/Tissue_hypoxia... · Tissue Hypoxia and Oxygen Therapy ˘ˇˆ˙˝˛˚˜

Tissue Hypoxia and Oxygen Therapy

����������� ��� �������

������������� �!"�# ���������� ���� �� � �� �������������

1. ���������� ���!���"#���� $��%&'��'�� �� 2. ���������#� ��#�'��� $��% 3. ������������*&��+��!���"#��,� - tissue hypoxia 4. ���������:��#����; �<�=*>�� $��%�!�*���?@>;A ��+�*��=%����B-�������B�� =:>C�>

��'���*��-�� 5. ;�-���?B ���� ���> ��� $��% 6. ���������;F"*�*���?B��+��+�� ��%� ��=*>�� $��% 7. �+�%&�&��+��+ ������!�� ���@>� +�� �� tissue hypoxia �B- ��=*>�� $��%C;;�-�� &�=:>

��?@>;A �%���

$%&'() 1. Pathway of oxygen transport 2. Causes of tissue hypoxia 3. Effect of oxygen administration 4. Oxygen devices with spontaneous breathing 5. Selection of patient for oxygen devices with spontaneous breathing 6. Effects of inadequate humidification of inspired gases 7. Humidifier and nebulizer 8. Evaluation of oxygen therapy 9. Oxygen hazard

��C�'�+=��;]���� '��� $��%��!���"&'�����#��C* ������C�'�������+:+ �&��@'C�>�>�

#���� $��% ���+�����*��=%�#>�C;����*���^ _�����!������ $��%�#>��@'�'�� �� �B-#�� `�$������C��� C$���� ��� �'�� �� =,� -; &�����*��=%����� $��%�#>�C; ;�-��< 21% #���� �����*�� �+��*B���' =*"'�;b `�$Cc&��% �'�� ��; &��+�C�'C�>�+,� -c��,��C#>�%_�*���C�'�+,� -?��; &������'�� _�������!���:+ �&C�>&��; &���� C;c��C�'#���� $��%

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�� $��%�+�*��=%�#>�C;=;��%-?'�#� ���B �;B+�� `�$���� <���B�;��c�����'?'� (diffusion) �#>�C;�����>�B���f��,��=;�� ( pulmonary capillaries) �#>��@' �-���B����B-,��=�$BB�=�+���� ,��=�$BB� �� $��%%-?'�#� �� oxidative phosphorylation =*> B���;b�B���� ATP (adenosine triphosphate) �����=*>�$BB�=:>�B������� B'� = ���!� �% ���&'��^#���'�� ��&'�C; c��C�'%!��;b&>��C�>�� $��%������&��� %� �� ���+�*��=%�#>�C; �&'�>��'�� ��� ���+,� -?��; &��+�#� ��#�'��� $��%�' =� _&�� *����;bc�������'���+�&>�� ���� $��%������� #��� '�,� -; &� _�!�=*>�'�� ��� ��,� -#���� $��% (tissue hypoxia) �!�=*>C�'�������!���:+ �&C�>&��; &� ���� ?@>��+�%��&>���+� ���@>=������,� -#���� $��% *B� ��=*>�� $��%�B- ��!��� $��%C;=:>=?@>;A �%��� &B��%���c��#�� ��=:>�� $��%�> �

*+�%� �*%�,�((�-.$/% (pathway of oxygen transport) (�@;�+� 1 )

http://www.niehs.nih.gov/factsheets/ozone/ithurts.htm

�@;�+� 1 Oxygen transport

cell

��

FiO2

ventilation

diffusion

http://www.rnceus.com/course_frame.asp?exam_id=18&

directory=abgs

http:www.biology.eku.edu/RITCHISO/301

notes6.htm

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�����&>%� ��*��=%��� FiO2 �+���+����&'�� ��&>�� ��#���'�� �� �����'��>�� FiO2 0.2 �#>�C;=;�� *B��%� �%-�+ ���B �;B+�� `�$�-���;�� (pulmonary gas exchange) ����� $��%%� �� ��,��� �#>��@';���B-#����� `�$������C��� C$���+��;b#����+��� C; $���#� ����� B'� %-&>��;�- ���> �

1. Alveolar ventilation &>���+ `�$?'��#>��� %� ;����'��; &� ���+������*��=%&���&'%�@ ;� *B��B� �'�B�&>��; &� C�'�+������*��=%��� �*���*B��B�&+� C�'�+,� -;���k� (atelectasis) ;��� � (pneumonia) *���!��' �;�� (pulmonary edema)

2. Diffusion &>���+ �����'?'�#�� `�$?'����B�;�� (alveoli) �B-��>�B���f��,��=;�� ( pulmonary capillaries) ��'��; &� c��&>���+�B���C*B?'�;��; &� C�'�+��>�B���,��=;�����&� (pulmonary embolism) *���&+� (pulmonary hypertension)

3. Perfusion &>���+�B�������� ��k� =;����<���*��- �� `�$�+�?'��#>��� (ventilation/perfusion matching)

*B��%� �%���+ ���B �;B+�� `�$�-* '���B����B-�������� $+���;b ���B `�$�-�����>�B���f�� (capillary gas exchange) $���#� ����� B'� %-&>��;�- ���> �

1. Capillary perfusion &>���+�B���C;�B+�����������' &'��^=*>��+���� ���� systemic circulation �B- pulmonary circulation &>���!���; &� C�'�+,� -*� =%B>��*B (congestive heart failure)

2. Oxygen delivery ;�- ���> � ��#�'��� $��%c���� $��%%-%�� ��n+c�c B���;b�' =*"'�B-B-B��= plasma �;b�' >�� �B-����� ���+�&� #��*� =% (cardiac output) ������!�=*>�� $��%C;�@'��������C�> Arterial O2 content = Dissolved O2 + Hb-bound O2 = (0.003 x PaO2) + (1.34 x Hb x SaO2) Oxygen delivery = Cardiac output x arterial O2 content = Heart rate x stroke volume x O2 content

���� ;F%%���+��+?B&'� ��!��� $��%C;����������� %-&>��#���@';����<n+c�c B��, oxygen saturation, PaO2 �B- cardiac output �&' ���+��$BB�%-C�>����� $��%C�>� ���&>��#� ��� ��������#��n+c�c B��= ��;B'���� $��%=*>�$BB��> � ���= oxyhemoglobin dissociation curve $���� ��������#��n+c�c B��= ��%�� ���� $��% (O2 affinity) %-�;�?�&�� pH, PaCO2 , ��<*,@��=�'�� ���B- 2-3-DPG (2-3-diphosphoglycerate) $���C�>%� ��&-��B�$��#����_��B������ &��� ����������-* '�� PaO2 �B- SaO2 $����'�� ��������#��n+c�c B��= ��%�� ���� $��%%-; &� ����� pH 7.4, ��<*,@���'�� �� 37 �����$B�$+���B- PaCO2 40 ��.;��� �&'�>��'���� B'� �;B+���;B�C;%� + %-�+?B�;B+���;B�� ��������#��n+c�c B��= ��%�� ���� $��% (oxygen - hemoglobin affinity changes) �!�=*>�+?B��+�����#�� oxyhemoglobin dissociation curve C�> (�@;�+� 2 )

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http:www.nursingceu.com/NCEU/courses/acidbase2/

�@;�+� 2. Oxygen - hemoglobin affinity changes

������ �� ����+�����#���� $��%C;���$>���!�=*>� ��������#��n+c�c B��= ��%�� ���� $��%�����#� n+c�c B��;B'���� $��%=*>��������=:>C�>B�B� ��%�!�=*>��������#���� $��% (tissue hypoxia)C�> ��C�>=,� -�B����;b�'�� (pH �@�, alkalosis), ��<*,@��&�!� (hypothermia), ,� -������C��� C$��&�!� (hypocarbia), �+ ��B�B�#�� 2-3-DPG $�����C�>�����C�>����B����+�� _����

������ �� ����+�����#���� $��%C;���# ��!�=*>� ��������#��n+c�c B��= ��%�� ���� $��%B�B� n+c�c B��;B'���� $��%=*>��������=:>�����#� ��C�>=,� -�B����;b �� (pH &�!�,acidosis), ��<*,@���@� (hyperthermia), ,� -������C��� C$���@� (hypercarbia), �+ �������#�#�� 2-3-DPG $�����C�>=,� -$+�*���#���� $��%�������

*B��%� n+c�c B��;B'���� $��%=*>��������=:>�B> �>������� $��%%���#>��@' ���B �;B+�� `�$�-����$BB� (cellular gas exchange) ��� ���B �;B+�� `�$?'� cell membrane �B- mitochondria �B-#� �� metabolism �+�� ��%� ��_C$��&'�C;

Tissue hypoxia

���*&�#��,� - tissue hypoxia %��B> ��%� � ��?��; &�#��#� �����*����� B'� $�����'�C�>&�����*&����+

1. Hypoxic hypoxia $���� ��%� � ��?��; &�#�� ���B �;B+�� `�$�+�;�� (pulmonary gas exchange) � ��������� $��% (PaO2) =�B���&�!�*�����+� '� ,� - hypoxemia $���� ��C�>%� *B�����*&�&�� BC ���B �;B+�� `�$; &��+��-���;��

1.1 FiO2 &�!� �:' =�+��@� (high altitudes) 1.2 Alveolar hypoventilation ���,� -�+� `�$�#>��@'���B�;��>�� '�; &� �!�=*>�+�� $��%=

���B�;�� (PAO2) B�B�

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1.3 Ventilation/perfusion mismatch ��� � ��C�'����B�-* '��;����< `�$�B-�B����+�?'� $����;b���*&��+����'���+����#��,� - hypoxemia �:' asthma, hemo/pneumothorax, atelectasis, pneumonia

1.4 Diffusion defect ��� � ��?��; &�#�����B�;���+��!�=*> `�$���'?'�C�>B!��� 1.5 Shunt effect ��� �+���B��#���B��� �!�=*>C�'���?����?� �B �;B+�� `�$

$��� ��=*>�� $��%�������!�=*>,� - hypoxemia �+�� ��%� ,� - ventilation/perfusion mismatch, hypoventilation �B- diffusion defect �+#�C�>

2. Anemic hypoxia =,� -$+� �!�=*>�+n+c�c B��C�'��+����=#� ��#�'��� $��% 3. Circulatory hypoxia �!�=*>������B����+�!��� $��%C;�@'��������C�'��+���� �:' ,� -

shock, arterial occlusion 4. Histotoxic hypoxia �$BB�C�'������!��� $��%C;=:>C�>�:' ,� - cyanide toxic ���^�+�

��#�'��� $��%; &� 5. Hypermetabolic hypoxia =,� -�+��$BB�&>�� �� metabolism �� '��+��-�� ���!���#��

;���B-*� =%%- supply C�> ��> BC �+� B'� ��#>��&>%-�!���; &� �:' ,� -&'��C�������;b���

Oxygen therapy

�����?@>��+��������*&�#�� tissue hypoxia �B> _&>������+��@> ��+ ��=*>�� $��%� '?@>;A �=,� -&'��^ $����+*B� ��=*>���+

1. ������� ��,� -�� $��%=�B���&�!� (correct document/suspected acute hypoxemia) ���+����������;����<�� $��%=���B�;�� ( alveolar oxygen tension; PAO2) �B-=�B��� (PaO2)

2. �����B��� ��#�� ��#���� $��%������� (decrease symptoms of chronic hypoxemia) c���w��-=?@>;A �c��;���:' c�����B�c;A���� �!�=*>�� ���*����B�B� �B-�!�=*>�@>�� &� %� ,� - chronic hypoxemia C�>��_ #�

3. �����B� ���!���#���-��*��=%�B-�-��*� =% (decrease cardiopulmonary workload) �����%� ,� -#���� $��%�!�=*>&>���+ ���!���#���-��*� =%�B-*B���B����� #� ������!�=*>�'�� ��C�>����� $��%��'����+���� ������+ ��#���� $��% %-�!�=*>�-��*� =%�B-*B���B���B>��*B C�>&�� BC =�?,@���+� 1

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�?,@���+� 1 ,� -*� =%B>��*B �+�� ��%� hypoxemia

���� ��=*>�� $��%%���+?B&'��'�� �����+

1. ����� PAO2�B- PaO2 2. :' �B� work of breathing �!�=*>?@>;A ��@>�� �*����B�B� 3. B� myocardial workload ���:' �B�c� ���+�%-� ��,� -��>�B���*� =%&+� (myocardial

ischemia) �B-*� =%�>�# ��!���B>��*B (right heart failure) � %� +�������@� ���#>��'�:+ #>�*>�� #>�� ��- �� = ��=*>�� $��% &�� AARC

Clinical Practice Guideline 2002 $���C�>=*>�!�����#�� oxygen therapy ��� ��=*>�� $��%=� ���#>�#>�+��� '�=����� �� (ambient air) ���+�����;x�� ��B-�� ���� ���+�� ��%� ,� - hypoxia

#>��'�:+#�� ��=*>�� $��% (indication of oxygen therapy)

1) �+*B� y�#�� ��#���� $��%=�B��� (documented hypoxemia) ��� �+,� - PaO2 < 60 ��.;���*��� SaO2< 90% �����*��=%�#>�=����� ��; &�*��� �'� PaO2 *��� SaO2 &�!� '��'��+�&>�� ��=,� -?��; &������'��

2) =���,� -�+���� '���%%-� ��,� - hypoxemia &����*B��C�>��� ���� �������&>�B> C�>� ' ?@>;A �*B��c��CkC*�>

3) ,� -����%_�#������ (severe trauma) 4) ,� - B>�����*� =%#���B��� ( acute myocardial infarction) 5) ��=*>�� $��%:' ���^*B�� ���!�*�&� �������'���:' *B�� �������B� *���

*B�� ��?'�&���-c�

#>�*>�� (contraindication) C�'�+#>�*>���+�:���%#���@' ����� ��<�&'��^

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#>�� ��- ���B-,� -��� $>��+���%� ��#� 1) ��%� ��,� - � ��*��=%=?@>;A ��+�*��=%��� ������+�'� PaO2 �+��� '�*�����'� �� 60 ��.

;��� c���+��'� PaCO2 �@� '�,� -; &� 2) ��%� ��,� -;���k� (absorption atelectasis), �� $��%�;b��� (oxygen toxicity) *��� �

���!���#���-��#�+� !�%�������;B ;B��=������*��=% (ciliary) �B-�-��,@����>� ���_��B���#� (leukocytic) �����=*>� ���#>�#>#���� $��%=B�*��=%�#>� (FiO2) > 0.5

3) � ��- �� ��=*>�� $��%=?@>;A ��+�C�>������%� paraquat *���C�>��������+�!���� bleomycin 4) #<-�!�?'�&������B�$��� =������*��=% � �%!� ��� ���#>�#>#���� $��%�+�=:>=*>&�!��+����

�����*B+ �B+��� ��&��Ck 5) ���+� ���#>�#>#���� $��%�+��@����� <�+�� ��CkC*�>%-�!�=*>#� ��&��Ck �����

����#� 6) � ��- �� ��=*>� ��:��' � ���� $��%c���w��- ��=*>� ��:����B-���f��

(nebulizer) �����������,� -&���:������+��+�=������*��=%C�>

� ����$>.%�� >�?(�� �((�-.$/%*(��, �� @

%!��;b&>����������B� �<-�� ������-��&'��^ (&�����+� 1) ?B&� %�B������������,� -#���� $��%� ����,� -?��; &�#��?@>;A �%� ,� -&'��^ ����?,@���+� 2

&�����+� 1 �� ������B�� #��,� -#���� $��%

�-�� �� ���-���&>*���;� B�� �� ���-��������

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A �$B.%) @C/ ) @C/$�D� ) @C/$�D�

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J%.B*(�(����P�C)?((�-.$/%�F )��+MI?�Q�@AGK) @C/$(� (oxygen devices with spontaneous breathing)

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1. Low-flow systems devices c��=*>�� $��% 100 % � '?@>;A �c��&���> � flow >�� '� 10 LPM �� �;b variable performance �����%� =*> flow >�� '� inspiratory flow rate demand #��?@>;A � �+ ���%��%���� ��%� ,��� �#>���?�� �!�=*>C�> FiO2 �� *���>��#���@' ��#��#�� reservoir, flow �+��;~��B-B� �<- ��*��=%#��?@>;A � $����+?B&'� minute ventilation ��; �<� low-flow �+���+ 1.1 Nasal cannula *��� nasal prongs (�@;�+� 3) ������=*>�� $��%C�> 24-40% c�� flow �+�

�����#� 1 LPM ����������� FiO2 C�> 0.04 �<+=:> flow >�� '� 4 LPM C�'%!��;b&>��=*>� ��:� C�'� ��;~� flow �� '� 6 LPM ����-�!�=*>?@>;A ��!���"�B-������*��=%�*>�C�> �� =:>=?@>;A ��+��� ���'�#>�����+� C�'&>�� ��� ���#>�#>#���� $��%�@��� �:' ?@>;A ����B�c;A����

1.2 Cannulocollar mask (�@;�+� 8) �;b��; �<�=*>�� $��%=?@>;A ��+��%�-���B> B� �<-�B>�� �� tracheostomy mask �&'�'��+���&'��;b�'��B_ �����=*>� ��:���� humidifier �' =*"'%-�;~� flow ��'��>�� 3 LPM ��+ ���!� <�;����$_&��� $��%�B>�� �� nasal cannula �����%� �+������������ ��,� -&���:������-��������*��=%= ��=*>� ��:���� nebulizer �� '���� humidifier

1.3 Simple face mask (�@;�+� 4) ������=*>�� $��%C�> 35-50% ,c���;~� flow �-* '�� 5-10 LPM %!��;b&>���;~� flow ��'��>�� 5 LPM �����;x�� �,� - rebreathing (exhaled CO2 ) �+���%������@',��= mask � �� �=*>������*>����+ ��%�!�=*>� �� ���-��������&'�?� *��*��� ����� <*>�C�> �� =:>=?@>;A ��� ���'�#>�����+� �&'&>�� �� FiO2 �� '� nasal cannula

1.4 Partial rebreathing mask (�@;�+� 5) ��� simple mask with reservoir bag. � ��;~� flow .=*>�� �� c��=*> bag C�'��� '� 1 = 3 *��� �����*���#�� bag #<-?@>;A �*��=%�#>��&_��+������=*>C�> FiO2 &���+�&>�� ��� ��;~� flow ��'��>�� 6-10 LPM ������=*>�� $��% C�> 40-70% �����%� ;�-��< 1 = 3 #��B�*��=%�� %-�#>�C;��@'= reservoir bag �B-?@>;A �������*��=%����� ��,��� ��?��?'���� exhalation port C�> �>��;~� flow >�� '�� ��&>�� ��#��?@>;A � %�����=*> FiO2C�'���+� �<+&>�� �� FiO2 �+��@�#� � �=*> humidifier �' ��> �

1.5 Non-rebreathing mask (�@;�+� 6 ) B� �<-�B>�� partial rebreathing mask &'�� �&���+ one-way valves 2 %�� %���� ��@'�-* '�� bag �B- mask ���+�����;x�� �C�'=*>B�*��=%�� (exhaled CO2 ) B���#>�C;= bag %���+� 2 %-�+�?';~����� < exhalation port ����� �C�'=*>*��=%����� ��,��� �#>��� C >�!�*���#��B�=:' �*��=%�� ��'�� ���� flow �+��;~�&>���@�����'��>�� 10 LPM �����=*>C�>�� $��%&���+�&>�� �� c��; &�������=*>�� $��%C�> 60-80% �&'&������+��%=*>�� $��%C�>��� 100% ��; �<�:��+����;b variable performance

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��@'�+ �����%� FiO2 �+�C�>��%C�'���+� �>�?@>;A �*��=%��_ �B-&>�� �� flow �� � ��;B+���;b��; �<�:����� *�����%&>��=�'�'�:' �*��=%�>��+#>��'�:+

�@;�+� 3 Nasal cannula �@;�+� 4 Simple face mask

�@;�+� 5 Partial rebreathing mask �@;�+� 6 Non-rebreathing mask

���; ;����< flow ��'��>���+�&>���;~������=*>C�> FiO2 &���+�&>�� ��#�� low-flow systems devices (&�����+� 2 )

&�����+� 2 Guidelines for estimating FiO2 with low-flow oxygen devices

Exhalation port

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2. High-flow systems devices ������=*> flow C�>��'� ��*����� '� respiratory flow demand #��?@>;A ������%� �+��; �<��+��������@������ ��,��� �#>���?�������=*>C�> flow �� ��&���+�&>�� �� �B> %��=*>� '?@>;A � ������ !�*� FiO2�+�&>�� ��C�> %��%���;b��; �<��+�=*> FiO2 �'�#>�����+� ����;b fixed performance ;�- ���> � 2.1 Air-entrainment system $����+ air-entrainment port �������@��� ��,��� �#>���?��

?'� jet orifice= flow ;����<�� c�������*B� ��#�� venturi effect (�@;�+� 7) ����+ negative pressure ?'��@�B_ ^ �!�=*>�@��� ���#>���C�>;����<�� c���+;�A�;���� ���#>�#>#���� $��%%� ,��� %-&>��=:>�' � �� nebulizer �����������=*>� ��:�C�>�� �*��-�!�*���=?@>;A ��+�=:> artificial airway �:' tracheostomy mask (�@;�+� 8) *��� T-piece (�@;�+� 9) ������=*>�� $��%C�>��'��>�� 35% � %� + ������=:>C�> �� aerosol mask (�@;�+� 10) �����=*>C�>� ��:��+���+����*B��%� ����'�:' �*��=%,��*B�� �������B� �����%� air-entrainment system =*>� ��:��'�#>���@�%��&>��&'� �� corrugate tube $����;b����'�#>��=*"' �C�'=*>�'�&������C�!� B��&� �;b*��!�,��=�'�

�@;�+� 7 Venturi effect

Jet

Entrainment port

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�@;�+� 8 Tracheostomy mask �@;�+� 9 T-piece �@;�+� 10 Aerosol mask

�.TG� ��F %�P flow *(�((�-.$/%H++ magic box C% high flow system, fixed performance

�������!� <;����< flow ��'��>���+�� ��;~������=*>C�> FiO2 &���+�&>�� ��C�>%� magic box

���+

�>�&>�� �� FiO2 0.6 %!��;b&>���;~� flow =*>C�>��'��>���� '�*�����'� �� respiratory flow demand #��?@>;A � �����'��>�� 3-4 ��'�#�� minute ventilation �����>�?@>;A �!�*� 50 kg *��=% 20 ����&'���+ �������!� < flow �+�&>���;~�C�>���+ minute ventilation = 5-7(ml/kg) x RR = (7 x50) x 20 = 7 LPM peak inspiratory flow rate = 3-4 #�� minute ventilation = 21-28 LPM &>�� �� FiO2 0.6 &>���;~� flow O2 &'� air 1:1 ���� &>���;~� flow ��'��>�� = 21/2 ��� 28/2 = 11-14 LPM

���� ������;�-��<����' #���� $��%&'��� ���+��#>���?��&����&���' �+��!� <C�> %� magic box �����&>�� �� FiO2 &���+�&>�� ��&��&�����+� 3 ���+

&�����+� 3 Approximate oxygen to air ratios for common oxygen concentration

Air 20

60

O2 100 40

40

O2100 : Air

40 : 40

1 : 1

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ME$�G@*(�� �C)?((�-.$/%�� >$*?>*?%�I� (Effects of inadequate humidification of inspired gases)

��=*>�� $��%� ���#>�#>�@�^ %!��;b&>��=*>� ��:��' ��> � �����%� �� $��%%-�!�=*>

������*��=%�*>� *B���B���f���& �B-� ��,� -?��; &�&'��^&����C�>���+ 1. �!�=*>�-�� cilia �!���?��; &� 2. ���*-�*+� #> 3. � �� necrosis #��?��*B���B���f�� 4. � ��������*��=%�*>��& �;b�?B 5. � ���B����� ���� <�������?��������*��=% 6. � �� ��&���:���+��������?��������*��=% 7. ,� -;���k� (atelectasis) 8. ,� -;��� � (pneumonia)

� �C)?(����P��� >J&'%��+�I,��+((�-.$/% (Humidifier and nebulizer)

%� �+�C�> B'� ���B> '���; �<� ��=*>�� $��%%!��;b&>���+��; �<�=*>� ��:�� ��@'C;�> � $�����; �<�=*>� ��:�;�- ���> � 2 ;�-�,�=*"'^ ��� humidifier �B- nebulizer

1. Humidifier (�@;�+� 11)=*>� ��:�C�>>�� '� nebulizer BC ��� ���' `�$?'�B�!�c��&���!�=*>������ ��:���������#�� `�$ %-�*_ '�C�>k��!�$����'�#>��=*"' ���+�?� ���?��>��*�����+� '� bubble humidifier �� =:> �� low flow system *���,� -?@>;A ��+�������*��=%; &�C�'C�>&>�� ��� ��:��@���

2. Nebulizer (�@;�+� 12) C�>� ' pneumatic jet nebulizer, ultrasonic nebulizer BC �����*B� #�� venture effect ����+�����!�?'��'��B_ ^ : ��B@ B��!�=*>� ��B-���f���B_ ^ =�@;B-���!� (�@;�+� 13) C�>� ��:��+��'�#>���@������%� �+���+�?� ���?���� �� =:>�' � �� artificial airway �+�&>�� ��� ��:��� �:' T piece , artificial nose ( heat and moisture exchanger)

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�����%� nebulizer =*>� ��:��'�#>���@�%��&>��&'� �� corrugate tube $����;b����'�#>��=*"' �C�'=*>�'�&������C�!� B��&� �;b*��!�,��=�'� c��%-&>���;~� flow =*>�� �� ��*��=%#��?@>;A � ���%-C�> FiO2 �+����+� ���� &C�>%� �+�?@>;A �*��=%�#>�%-&>���+C�!��*B����@'���� < ;B���'�*������� <*>� � (�@;�+� 14 )

�@;�+� 11 Humidifier �@;�+� 12 Nebulizer

�@;�+� 13 Nebulizer with venturi effect

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���������;� ���& &'��#�� humidifier �B- nebulizer C�>���&�����+� 4 ���+

&�����+� 4 � ���& &'��#�� humidifier �B- nebulizer

Humidifier Nebulizer

Humidification gaseous aerosol Airway target upper airway lower airway Flow system low-flow high-flow FiO2 variable fixed

Tubing small-bored corrugated Cost cheaper expensive Nosocomial infectious less more

� ����$>.%MI?�Q�@)E��[B?��+((�-.$/% (evaluation of oxygen therapy)

*B��%� �+��+ ��=:>��; �<��� $��%�B> %!��;b�+�%-&>���+ ��;�-���?B ���� ���> ��� $��%�B-%-&>���+ ���fx��- �����+

1. Patient �+ ������fx��- �����+ 1.1 Clinical assessment c��;�-����-��&'��^ C�>� ' �-�� cardiovascular, pulmonary

�B- neurologic status '��+#�%� ����*���C�' 1.2 Assessment of physiologic parameters C�>� ' ��&� % PaO2 *��� oxygen saturation

c���w��-?@>;A ��+�C�>��� ���� ���> �,� -&'��^���+ - �����C�>��� ���!�����> ��� $��%*���,��= 12 :�� c��*B��%� C�>��� ���� ���> �

FiO2 < 0.4

�@;�+� 14 Nebulizer �B- corrugate tube �'�=*"' �*_C�!��+�;B���'�

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- ,��= 8 :�� c��*B��%� C�>��� ���� ���> � FiO2 > 0.4 (� ����?@>;A ��+���@'= postanesthetic care unit)

- ,��= 72 :�� c��=?@>;A � myocardial infarction - ,��= 2 :�� c��=?@>;A �c�����B�c;A���� (COPD)

2. Equipment %!��;b&>���+ ���fx��- ���B-;����;B+����; �<�&���,��?@>;A � 2.1 &>��&� %�:_���; �<�=*>�� $��%�� :����'��>�� 1 ����&'� � 2.2 &>��&� %�:_���; �<�=*>�� $��%�'������#��� '� 1 ����&'� � c���w��-��; �<�=*>

�� $��% =?@>;A ����+ - �+� c>��+ ���;B+���;B�#��� ���#>�#>#���� $��%�+�=:> c���w��-?@>;A ��+�=:>

high-flow blending systems - ?@>;A ��+�=�' artificial airways - ?@>;A ��+�=:> heated gas mixture - ?@>;A ��+��� �����C�'���+�*���C�>��� FiO2 > 0.5

2.3 &>���+ ��&� %�����; �<��� $��%�+�?@>;A �=:>��@'#<-��B����>��?@>;A ��:' C; ��_ $���� *����>��&� ?@>;A �

*?($�G@*(�� �C)?((�-.$/% ( oxygen hazard) ��=:>�� $��%�+#>��+ �B-#>�� ��fx��- ������+�C�> B'� C;�B> �&' ��=:>�� $��%� ���#>�#>�@�*���=:>&��&'� ��;b�-�-� B�� �!�=*>� ��,� - oxygen toxicity �B-� ��?B��+�&'�� �� -&'��^ &����C�>���+ 1. Physiological hazard from hyperoxygenation

1.1 ?B&'��-�� CNS �!�=*>� ��,� - tremors, twitching, paralysis �B- convulsion C�> $���������� �� ��C�>��� hyperbaric pressure (�� $��%�+�� ������ '� 1 ����� ��)

1.2 ?B&'��-��&� �!�=*>� ��,� - retinopathy of prematurity $����� %-��=��� �B�� '� !�*��+�C�>����� $��%% PaO2 �� ?��; &�%�!�=*>� ��,� - retinal vasoconstriction �B- necrosis =�+����

1.3 ?B&'��-��������*��=% - �!�=*>������*��=%�*>� ���*-�*+� #> B� ���!���#���-�� cilia - �!�=*> � ��*��=%=?@>;A �c�����B�;A��c�� �����%� ��+� hypoxic drive - �!�=*>�@"��+�,� - hypoxic pulmonary vasoconstriction - �!�=*>� ��,� - absorption atelectasis �����%� �� $��%C;���+�&!��*'�

Cc&��% �!�=*>���B��k�

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- �!�=*>� ��,� - bronchopulmonary dysplasia �B- pulmonary hypertension & fibrosis &����C�> ����?,@���+� 3

�?,@���+� 3 ,� - pulmonary hypertension & fibrosis �+�� ��%� high FiO2

1.4 ?B&'��-�� metabolic �!�=*>�'���B+� !�*� B�C�> 1.5 ?B&'��-��*� =%�B-*B���B��� �!�=*>� ��,� - pulmonary vasodilatation �B-

systemic & cerebral vasoconstriction 2. Psychological dependent 3. Mechanical hazard �!�=*>� ��CkC*�>C�>c���w��-�� $��%� ���#>�#>�@� 4. Bacterial contamination %� � ��:��+�B�B� ������B�;��c���w��-�����=:>�' � �� nebulizer

%� ;F"*� ��� ��,� - oxygen toxicity %��� ��- ��C�'=*>�� $��% 100% � � 24 :�� c��*����>�=*>� ���#>�#>B�B��;b 70% C�'� �� � 48 :�� c�� � ���#>�#> 50% C�'� �� � 5 �

���� ��=*>�� $��%�+���#>��+�� ���&���+�C�> B'� C;�B> �&' _�+#>���+�*� =:>� ���#>�#>�@�^ *���=:>�;b� B�� ����?@>��+�%��&>��&�-*� �B-�@>%� �B�� =:>�� $��%&��� ��%!��;b�B-�+#>��'�:+��'�� *B��%� �+�=:> ��?@>;A ��B> _&>���+ ���fx��- ��&B��� B�������,� -#��?@>;A ��;B+��C; c����%&>���;B+��:��#����; �<� ��=:>�����?@>;A ���'B�*�������������� $��%�� C�>�����?@>;A ��� ���+#�*���*��#>��'�:+

$(�� �(? �(.�

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1. Scanlan CL, Heuer A. Medical Gas Therapy. In: Scanlan CL, Wilkin RL, Stoller JK, editors. Egan�s Fundamentals of Respiratory Care. 7th ed. St. Louis : Mosby; 1999: 738-765.

2. Chang DW. AARC Guideline : Oxygen Therapy for Adults in Acute Care Facility. Respiratory Care 2002; 47(6):717-20.

3. Stoelting RK. Lungs. In: Stoelting RK, editor. Pharmacology and Physiology in Anesthetic Practice. 3rd ed. Philadelphia : Lippincott-Roven; 1999: 682-691.

4. Stoelting RK. Pulmonary gas exchange and blood transport of gases. In: Stoelting RK, editor. Pharmacology and Physiology in Anesthetic Practice. 3rd ed. Philadelphia : Lippincott-Roven; 1999: 692-701.

5. Wojciechowski WV. Mathematics. In: Wojciechowski WV, editor. Respiratory Care Sciences : An Integrated Approach. 3rd ed. Albany : Delmar ; 2000: 19-22.

6. Branson RD. Gas delivery systems: regulators, flowmeters, and therapy devices. In: Branson RD, Hess DR, Chatburn RL, editors. Respiratory Care Equipment. 2nd ed. Philadelphia : Lippincott Williams & Wilkins; 1999: 55-85.

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8. Saposnick AB, Hess DR. Oxygen therapy: administration and management. In: Hess DR, MacIntyre NR, Mishoe SC, Galvin WF, Adams AB, Saposnick AB, editors. Respiratory Care: Principles and Practices. Philadelphia : W.B. Saunders Co.; 2002: 592-611.

9. Fink JB, Hess DR. Humidity and aerosal therapy. In: Hess DR, MacIntyre NR, Mishoe SC, Galvin WF, Adams AB, Saposnick AB, editors. Respiratory Care: Principles and Practices. Philadelphia : W.B. Saunders Co.; 2002: 633-664.

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