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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) . |