سی جریان برها لومن پیکربندی تاثیر
ال
•v is the maximum velocity
•L is a characteristic linear dimension,
•μ is the dynamic viscosity of the fluid
•ν (nu) is the kinematic viscosity
•ρ is the density of the fluid
R=
𝜌𝑣𝑙
𝜇
DD دایره
ای
1730 950
Re𝐶𝑟𝑖𝑡 > 2300
Saeid Safari,MD.
CENTRAL VENOUSLINE PLACEMENT
COMPLICATIONS-IMMEDIATE
• FAILURE TO CANNULATE
• PSEUDOANEURYSM
• CATHETER MALPOSITION
• ARTERIOVENOUS FISTULA
• VESSEL LACERATION
• HEMATOMA
• ARRHYTHMIA (WIRE OR
CATHETER)
• AIR EMBOLISM
• PNEUMO / HEMO THORAX
COMPLICATIONS-DISTANT
• PNEUMO / HEMO THORAX
• AIR EMBOLISM
• ARRHYTHMIA (CATHETER)
• SKIN INFECTION OR BACTEREMIA
• STENOSIS OR THROMBOSIS OF VESSEL
• THORACIC DUCT INJURY-CHYLOTHORAX
• NERVE INJURY (BRACHIAL PLEXUS,
SYMPATHETIC CHAIN, PHRENIC)
• CARDIAC TAMPONADE
29.
Saeid Safari,MD.
•
گایدوایر ازناشی مکانیکی عوارض
•
کینک
شدن
و
پیچ
خوردگی
•
پارگی
• Jae Jun Lee, A complication of subclavian venous catheterization: extravascular kinking, knotting,
and entrapment of the guidewire-A case report, Korean J Anesthesiol 2010 Mar; 58(3): 296-298
• Hyun-Seok Han, Successful removal of kinked J-guide wire under fluoroscopic guidance during
central venous catheterization -A case report, Korean J Anesthesiol. 2011 May;60(5):362-364.
English.
Saeid Safari,MD.
Mapleson
• describedfive circuits, designated A through E.
Subsequently, in 1975, willis and coauthors described the F system,
which was added to the original five.
• The mapleson systems consist of several common components,
including a connection point to a facemask or endotracheal tube,
reservoir tubing, fresh gas inflow tubing, and an expiratory pop-off
valve or port.
• All the mapleson circuits except for the E version use a bag as an
additional reservoir.
63.
Saeid Safari,MD.
Mapleson
• Threedistinct functional groups can be seen: A, BC, and DEF groups.
• The mapleson A, also known as the magill circuit, has a spring-loaded
pop-off valve located near the facemask, and fresh gas flow enters the
opposite end of the circuit near the reservoir bag.
• In the B and C systems, the spring-loaded pop-off valve is located near
the facemask, but the fresh gas inlet tubing is located near the patient.
• The reservoir tubing and breathing bag serve as a blind limb where
fresh gas, dead space gas, and alveolar gas can collect.
64.
Saeid Safari,MD.
“T-PIECE” GROUP
•Finally, in the mapleson D, E, and F, or “t-piece” group, fresh gas enters
near the patient, and excess gas is vented off at the opposite end of the
circuit.
• Even though the components and their arrangement are simple,
functional analysis of the Mapleson systems can be complex.
65.
Saeid Safari,MD.
The amountof carbon dioxide rebreathing associated with each
system is multifactorial, and variables that dictate the ultimate
carbon dioxide concentration include the following:
• (1) the fresh gas inflow rate,
• (2) minute ventilation,
• (3) the mode of ventilation
(spontaneous or controlled),
• (4) tidal volume,
• (5) the respiratory rate,
• (6) the inspiratory-to-expiratory
ratio,
• (7) the duration of the expiratory
pause,
• (8) the peak inspiratory flow rate,
• (9) the volume of the reservoir tube,
• (10) the volume of the breathing bag,
• (11) ventilation by mask,
• (12) ventilation through an
endotracheal tube, and
• (13) the carbon dioxide sampling site.
66.
Saeid Safari,MD.
MAPLESON (A)
•The performance of the mapleson systems is best understood by studying
the expiratory phase of the respiratory cycle.
• During spontaneous ventilation, the mapleson A has the best efficiency of
the six systems because it requires a fresh gas inflow rate of only 1 times
minute ventilation to prevent rebreathing of carbon dioxide.
• However, it has the worst efficiency during controlled ventilation because a
minute ventilation as high as 20 L/minute is needed to prevent
rebreathing.
67.
Saeid Safari,MD.
“T-PIECE” GROUP
•Systems DEF are slightly more efficient than systems BC.
• To prevent rebreathing carbon dioxide, the DEF systems require a fresh
gas inflow rate of approximately 2.5 times minute ventilation, whereas
the fresh gas inflow rates required for BC systems are somewhat higher