Monitoring of Non-Invasive Blood Pressure by roi15698


									Monitoring of Non-Invasive Blood Pressure

Patricia Vendramim, RN, MSc
         Charge Nurse of Pediatric Intensive Care, Hospital Samaritano, São Paulo, Brazil

Abstract                                          (NIBP) measurement. These include 1.
This lecture was presented at the 1st             auscultation, 2. oscillometric, 3. ultrasonic,
International Symposium of Nursing in             and 4. plethysmographic methods.
Pediatric and Neonatal Intensive Care in the           The non-invasive measurement of
city of São Paulo - Brazil (June 2006). The       blood pressure began with the introduction
author offers supporting evidence for             of the sphygmomanometer with a mercury
understanding non-invasive blood pressure         column by Riva-Rossi, in 1896. However, it
measurement methods. Also examined are            was in 1905 that the auscultation method
studies that search for methods that              (Korotkoff) was introduced in the clinic and
minimize        measurement       errors.The      is still being used, without any significant
oscillometric method is often cited in the        changes1-3.
literature. Although it the most frequently            Progress in NIBP measurement can be
used method, it also seems to result in less      attributed to various difficult to control
accurate values. Additional studies on            factors that can modify the result,
pediatric patients are required to validate       jeopardizing the accuracy of the measure4.
these findings.                                        Use of the auscultation method has
                                                  been diminished because of several
Key words: blood pressure, non invasive           factors: use of the mercury manometer has
blood pressure, pediatric nursing                 been discouraged for ecological reasons,
                                                  difficulties with calibration of aneroid
     The topic I was asked to present at this     gauges, pressure sores resulting from the
Symposium refers to indirect blood                cuff, debates regarding appropriate body
pressure measurement methods. When                sites for measurement, the clinician skill
taking into consideration this vital sign         and controversies regarding cuff size.
within the complex environment of pediatric       Studies have indicated that the ratio
intensive care,        you may         possibly   between the brachial circumference and
underestimate its importance, due to the          the cuff width (resulting in reduced error as
special and sophisticated equipment that          the ratio approaches the optimal value)
the technical market has to offer; especially     should be 0.464-6.
in the past 10 years. But it is as from the            When analyzed for their theoretical
Systemic Arterial Pressure (SAP), many            significance, these concerns usually make
times obtained only through an indirect           their application more difficult in practice,
method, that a series of therapeutic              especially when referring to pediatric
measures are taken when caring for a              intensive care4.
critically ill child.                                  Ultrasonography is another available
     It is possible to note in the literature a   technique        for     blood      pressure
large number of scientific reports that           measurement. The speed of the blood
examine responses to medical treatment of         floww is measured via Doppler, resulting in
systemic arterial hypertension or shock.          a blood pressure value. This method has
However, many do not address, or even,            been used to visualize the thickness and
state explicitly the method used to measure       compliance of arteries, mainly as a specific
the blood pressure. We basically have four        exam to measure predictors of heart
methods for non-invasive blood pressure           disease, rather than measuring SAP7.
Pediatric Intensive Care Nursing 7(2) 2006                                                    20
Although it is used in research with good         though lower. This can be noticed
accuracy, it may not be as viable in clinical     especially in the diastolic pressure, for
practice due to the high cost and                 adults or children. It can also result in an
specialized expertise required for accurate       arterial hypertension (around 17%), if the
measures7-8.                                      pressure         decrease        is     treated
     Automatic measurement equipment for          indiscriminately9, 14.
non-invasive blood pressure through the                 An alternative to this bias is the use of
oscillatory method arose on the market            the mean arterial pressure. The literature
around 1970, little after microprocessors         agrees that this data is less affected by
appeared. Thus, sensors replaced the              change of blood vessels tone than with
stethoscope, in order to detect the               systolic and diastolic pressures, because it
Korotkoff sounds. Up to the end of the            is obtained when the variations reach their
seventies, this method was implemented            biggest amplitude in the cuff deflation3, 9.
mainly in surgical theatres, to enable the        Given the elative lack of accuracy
clinical patient monitoring when undergoing       associated with NIBP methods, direct
anesthesia3,9.                                    measurements are still required for critically
     Bio-engineering            developments      ill children or neonates in the intensive care
gradually made this method attractive to          setting16.
the hospital community (and outside as                  Regardless of the problems outlined
well), by offering an objective instrument        above, oscillometric SAP measuring
that is not conducive to the influence of the     devices are still commonly used in practice.
observer, not dependant on external               However, they present a problematic
auscultation devices, while allow a series        accuracy. It is therefore necessary to
repeated measures. Another positive               conduct additional randomized clinical
aspect is the simplicity in executing the         studies in order to better analyze the
technique and the low risks involved with         measures in different groups15.
its use, compared to the auscultation                   Regarding accuracy, studies with
method, concerning the frequency or               adults and children have been conducted
severity of purpuric lesions10-11.                to evaluate if the modified oscillatory
     Nevertheless, a case was reported in         method (which generates continuous
the United Kingdom describing the                 values of the pressure with a waveform)
development       of    skin    necrosis    by    provided       more     satisfactory    results.
hypoperfusion, in an elderly critical patient,    However, these studies are still in progress
which occurred due to automatic cuff              and with limited samples. They therefore
inflation every 15 minutes (with alternation      require further replication17.
of the arms every four hours)12. Other                  The plethysmography model described
reported         complications        include:    by Penaz in 1973 has been used for
compressive neuropathy, petechial rash,           continuous        measurement.              The
ecchymoses, thrombophlebitis and venous           plethysmographometer is adjusted on the
stasis13.                                         middle finger of the hand through
     Regardless of these potential risks, the     pneumatic regulation, registering a reading
use of this method in clinical practice was       in mmHg through the infrared light, which
accepted and incorporated ino our                 records immediate pressure variations.
environment during the last 20 years, but         Some scholars who have evaluated this
apparently      without    related   scientific   method, concluded that when compared to
investigations      and/or     standardization    invasive measures, it presents slightly
through guidelines3,14. Confirming this fact,     higher systolic pressures – a difference that
a British study revealed that 90% of the          is statistically yet not clinically significant.
monitors available in the European Market         Correlational data demonstrated that mean
were not validated by clinical studies15.         arterial pressure is more accurate data18-19.
     The trend observed in research has                 Besides the efforts to demonstrate the
indicated that use of the oscillometric           accuracy of this procedure, researchers
method commonly fails regarding the ratio         have also tested devices for the ankle and
of cuff sizes and arm circumference. Also,        arm in adults. This remains a method that
it reproduces values with a smaller               is scarcely disseminated in practice,
variation than the conventional method,           especially in Brazil, since clinical research
Pediatric Intensive Care Nursing 7(2) 2006                                                      21
has involved limited samples and do not         essencial através da metodologia não-
consider carefully examine the pediatric        invasiva. J Bras Nefrol. 1998; 20(2): 191-7.
patient20. This raises some important           8.       Abassade P, Baudouy PY, Gobet L,
questions: How to adjust a sensor on a          Lhosmot JP. Comparison of two indices of
middle finger of a newborn’s hand? What         arterial distensibility: temporal apparittions of
are the risks of causing a burn?                Korotkoff sounds and pulse wave velocy. A
     Although oscillometric method NIBP         Dopller echocardiography and ambulatory
measurement is the most used method in          blood pressure monitoring study. Arch Mal
professional practice, scientific data          Coeur Vaiss. 2001; 94(1): 23-30.
suggest it has limited reliability21.           9.       Imbelloni LE, Beato L, Tolentino AP,
     Another big question to consider is the    Souza DD, Cordeiro JA. Automatic Blood
scarcity of original studies and their          Pressure Monitors. Evaluation of Tree
replication to the pediatric and neonate        Models in Volunteers. Rev Bras Anestesiol.
intensive care population. Therefore, the       2004; 54(1): 43-52.
big challenge has been to seek the              10.      Saul L, Smith J, Mook W. The safety
integration of scientific evidence with         of automatic versus manual blood pressure
practice, which can support the complexity      cuffs for patients receiving thrombolytic
of the nursing, without separating art from     therapy. 1998; 7(3): 192-6.
science.                                        11.      Cavalcanti S, Marchesi G, Ghidini
     We consider it extremely important that    C. Validation of automatic oscillometric
the nurse be aware of such knowledge            sphygmomanometer (HDBPM) for arterial
concerning SAP measurement. This relies         pressure          measurement              during
on science and not on ritual, as it was for     haemodialysis. Med & Biol Eng & Comput.
the beginnings of the profession,               2000; 38(1): 98-101.
constituting the essence of nursing care        12.      Devbhandari Mohan P, Shariff Z
and for this reason cannot be seen as           Duncan AJ. Skin necrosis in a critically ill
common sense.                                   patient due to a blood pressure cuff. JPGM;
                                                2006; 52(2): 136-8.
References                                      13.      Lin CC, Jawan B, de Villa MV, Chen
1.      Looney J. Blood pressure by             FC, Liu PP. Blood pressure cuff
oscillometry. Med Electron. April 1978:57-      compression injury of the radial nerve. J Clin
63.                                             Anesth 2001; 13:306-8.
2.      Ramsey       III   M.    Non-invasive   14.      Norderhaug PI. Ambulatory blood
automatic determination of mean arterial        pressure measurement. A review of
pressure. Med Biol Eng Comput, 1979; 17:        internacional studies. The Norwegian
11-18.                                          Knowlewdge Centre for the Health Services
3.      Jilek J, Fukushima T. Oscillometric     (NOKC) 2000.
Blood     Pressure       Measurement:    The    15.      Sims AJ, Menes JA, Bousfield DR,
Methodoly, Some Observations, and               Reay CA, Murray A. Automated non-
Suggestions. Biomed Instrument Technol.         invasive blood pressure devices: are they
2005; 39: 237-41.                               suitable for use? Blood Press Monit 2005;
4.      Arcuri E. From Riva Rocci,              10(5): 275-81.
Recklinghaunsen        and    Korotkoff    to   16.      Dannevig I, Dale HC, Liestol K,
nowadays: the challenge of blood pressure       Lindemann R. Blood pressure in the
measurement accuracy. Online Brazilian          neonate: three non-invasive oscillometric
Journal of Nursing. 2005; 4:(3)----             pressure monitors compared with invasively
5.      Carter BL. Blood pressure as a          measured blood pressure. Acta Paediatrica
surrogate end point for hypertension. Annals    2005; 94(2): 191-6.
of Pharmacoterapy. 2002; 36: 87-92.             17.      Mc Cann ME, Hill D, Thomas KC,
6.      Evans D, HodgKinson B, Berry J.         Zurakowski D, Laussen PC. A comparison
Vital signs: a systematic review. Joanna        of radial artery blood pressure determination
Briggs Institute for Evidence Based Nursing     between the Vasotrac device and invasive
and Midwifery. 1999: 1-106.                     arterial blood pressure monitoring in
7.      Plavnik FL. Revisão/ Atualização        adolescent undergoing scoliosis surgery.
em Hipertensão Arterial: Avaliação do           Anesth Analg 2005; 101(4): 978-85.
sistema vascular na hipertensão arterial
Pediatric Intensive Care Nursing 7(2) 2006                                                    22
18.    Polito   MD,      Farinatti    PTV.               stress compared to intra-arterial pressure.
Considerations    on    blood      pressure              Cardiovasc Res 1990; 24(3): 214-21.
assessment during resistive exercise. Rev                20.      Bogert LW, van Lieshout JJ. Non-
Bras Med Esporte 2003; 9(1): 25-33.                      invasive pulsatile arterial pressure and
19.    Imholz BP, Settels JJ, van der                    stroke volume changes from the human
Meiracker AH, Wesseling KH, Wielling W.                  finger. Exp Physiol 2005; 90(4): 437-46.
Non-invasive continuous finger blood                     Beales D. How accurate are automated
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                                                         Nurs        2005;        10(7):       421-4.


 Ethical Implications of Errors in ICU Nursing Practice

 Katia Grillo Padilha, BSN, PhD
         Faculty member, Department of Medical Surgical Nursing. School of Nursing
         University of São Paulo, Brazil

Abstract                                                          The second, according to Anne
This       article     discusses     general             Davis1, refers to the fact that nursing has
considerations on ethical nursing practice               never considered ethics an unimportant
relating to errors in ICUs, according to the             issue or a kind of fashion. Nursing history
bioethical principles of beneficence and                 has shown a growing literature, as well as a
nonmaleficence. In the health care context,              number of ethical activities in professional
the need for error analysis under a systemic             associations, in codes of ethics and health
focus in a safe non-punitive culture is                  care standards and protocols. According to
highlighted, so that effective preventive                Davis1, “nothing has been irrelevant to the
measures are adopted in such services. It is             permanent and intentional commitment with
a mandatory ethical commitment for nurses                ethics for the nursing profession”.
working in ICU that they provide care to                          The third aspect concerns the
assign a priority to patient dignity in a                technology that has been developed in
system that ensures more protection and                  recent decades. It has brought new and
less risks and failures.                                 complex challenges to the health care
                                                         professional and has become a core focus
Introduction                                             of ethical discussions.
         The ethical implication of errors in                     In this sense, in the face of the
intensive care nursing practice requires                 diagnostic and therapeutic tools available for
some consideration of the general ethical                health care and the appeal for technological
aspects of the profession.                               innovations for consumers, the problems
         The first relates to nurses’                    these professionals will face tend to be more
competence whose main basis is “know how                 and more of an ethical nature than
to behave”, a mandatory ethical component                technical.2 Therefore, this reality reinforces
in nursing practice, which complements                   the great number of ethical problems
scientific knowledge. This involves ‘know-               present in the daily life of the nurse,
how’ skills, including knowing how to interact           especially in the intensive care area. It is
with each other.                                         within this perspective that actual and
                                                         potential errors take place in ICU practice.
Pediatric Intensive Care Nursing 7(2) 2006                                                          23

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