الفهرس 
Cardiovacsular System MonitoringOnly 14 pages are availabe for public view
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Abstract
Effective monitoring reduces the potential for poor outcomes that
may follow anesthesia by identifying derangements before they result in
serious or irreversible injury. Standards for basic anesthetic monitoring
have been established by the American Society of Anesthesiologists
(ASA). Today’s standards (last amended on October 25, 1995) emphasize
the importance of regular and frequent measurements, integration of
clinical judgment and experience, and the potential for extenuating
circumstances that can influence the accuracy of monitoring systems.
(ASA, 2003) .
Standard I requires qualified personnel to be present in the
operating room, to monitor the patient continuously and modify
anesthesia care based on clinical observations and the responses of the
patient to dynamic changes resulting from surgery or drug therapy.
Standard II focuses attention on continually evaluating the patient’s
oxygenation, ventilation, circulation, and temperature and specifically
mandates the following:
1- Using an oxygen analyzer with a low concentration limit alarm during
general anesthesia.
2- Quantitative assessment of blood oxygenation during any anesthesia
care
3- Continuously ensunng the adequacy of ventilation by physical
diagnostic techniques during all anesthesia care. Quantitative
monitoring of tidal volume and capnography are encouraged in
patients undergoing general anesthesia.
4- Ensuring the adequacy of circulation by the continuous display of the
ECG, and determining the arterial blood pressure at least at 5 minute
intervals. During general anesthesia, circulatory function is to be
continually evaluated by assessing the quality of the pulse, either
electronically or by palpation or auscultation.
5- Endotracheal intubation requires qualitative identification of carbon
dioxide in the expired gas. During general anesthesia, capnography
and end-tidal carbon dioxide analysis are encouraged.
6- During alii anesthetics, the means for continuous measuring the
patient’s temperature must be available. When changes in body
temperature I are intended or anticipated, temperature should be
continuouslt measured and recorded on the anesthesia record. ( ASA ,
2003).
OXimetr~readings can be altered by a number of factors. The site
of measuremenf must be clean and dry and have minimal movement to
permit adequate signal transmission. Nail polish and other environmental
factors such as bright overhead lighting or sunlight can also interfere with
transmission. Cold ambient temperature, leading to peripheral
vasoconstrictioj’ decreases skin blood flow and may result in difficulty
for the oximeter to determine pulsatile flow needed for a reading.Also
Patient conditilns that likewise are associated with poor peripheral
perfusion, such as decreased cardiac output, some dysrhythmias, shock,
and certainly cardiac arrest, may result in difficulty for the oximeter to
determine puis ~ile flow and giving a valid reading (Murray et af, 2000).
Although the inherently reliability of pulse oximetry has led to its
wide use in arsthesia and critical care,remaining problems include
motion sensitivity.causing false alarms and erronerous measurements, and
hypoperfuusSilon’lIausm. g Iof’ss 0 signaI.severaI manufacturers have
developed proprietary methods to address these problems based on
analysis of frbquency,waveform morphology,or saturation.Puplished
evidence supports the ability of new generation pulse oximetry to detect
hypoxemic epihodes more reliably than conventional devices under
conditions of pi tient motion and hypo thermic hypoperfusion.(Irita k et
at, 2003)
Capnography, the measurement of C02 in expired gases,has
evolved ;0 the rt few Y”’” into a commonly used procedure. Wh,,,,,
a variety of te ihniques can be used for C02 measurement( e.g., mass
spectrometry, Raman analysis), most capnographs rely on infra red
absorption. Use of this technique can reliably and quantitatively provide
vital resPiratol monitoring information in the operating room and in all
critical ’M’ MT.(Gm”,o.””o Js etal, 2000).
PAC profdes measurements of several hemodynamic parameters
such as central yenous pressure (CVP), pulmonary artery pressure (PAP),
pulmonary artery occlusion pressure(PAOP)or pulmonary capillary
wedge pressure (PCWP) and other derived parameters .. There have been
a number of su veys to determine how well physicians, nurses, and other
health care practitioners interpret PAC data. Even in the realm of
idealized press re tracings and data presentation, nurses, [ American
physicians, and European physicians’all incorrectly interpret the data in
25% to 50% lf cases. This deficiency has been recognized by the
National Instit~les of Health and a variety of professional societies who
have created in;liatives and resources to improve PAC education. ( PAC
education ”,Oj1’” 2005).
It is difficult, and often impossible, by clinical evaluation of
recovery of neuromascular function, to exclude with certainly clinically
significant residual curarization.,so in daily practice significant residual
block can be excluded with certainly only if objective methods of
neuromascular monitoring are used. Good evidence -based practice
dictates that clinicians should always quantitate the extent of
neuromascular recovery using objective monitoring. At aminimum, the
TOF ratio should be measured during recovery whenever a non
depolarizing neuromascluar block is not antagonized.(Eriksson Li, 2003).
The effects of anesthesia and surgery on the eNS may be
monitored by recording processed EEG activity, as in the bispectral index
or the Patient State Index. These indices are used as measures of
hypnosis,sedation, and the probability of recall using a variety of
anesthetic agents (thiopental, propofol, midazolam, isoflurane, and
sevoflurane). The use of the BIS can facilitate faster emergence and
improve recovery from general anes thesia by allowing more precise
titration of anesthetic effect. (Lehmann A et al , 2002) .