Table of Contents  
REVIEW ARTICLE
Year : 2016  |  Volume : 9  |  Issue : 1  |  Page : 6-11

Consent for anesthesia


1 Department of Anaesthesia, Government Medical College, Amritsar, Punjab, India
2 Department of Psychiatry, Government Medical College, Amritsar, Punjab, India
3 Department of ENT, Government Medical College, Amritsar, Punjab, India

Date of Submission13-May-2014
Date of Acceptance03-Aug-2014
Date of Web Publication17-Mar-2016

Correspondence Address:
Attri Joginder Pal
Department of Anaesthesia, Government Medical College, Amritsar - 143 001, Punjab
India
Login to access the Email id

Source of Support: None, Conflict of Interest: None


DOI: 10.4103/1687-7934.178872

Rights and Permissions
  Abstract 

Modern anesthesia practice has become technically more challenging. Today's anesthesiologist is more often involved in administering anesthesia to elderly and sick patients who are having other comorbidities, with their inherent risks. This leads to increased morbidity and mortality. Anesthesiologists are not able to carry out detailed discussions about the proposed procedure with their patients because of work load and time restraints. Hence, they are not able to build up healthy relationship with their patients. Hence, whenever some eventuality takes place, patients and relatives react in a hostile manner. In this situation, if a negligence case goes to the court, then a well-informed anesthesia-specific consent can help an anesthesiologist to prove his or her side during legal proceedings. In this article, consent for anesthesia is reviewed with respect to its three major components - that is, information, decision-making capacity, and autonomy of the patient.

Keywords: anesthesia, informed consent, medical negligence


How to cite this article:
Gagandeep K, Neeru B, Pal AJ, Singh SK, Parkash KA. Consent for anesthesia . Ain-Shams J Anaesthesiol 2016;9:6-11

How to cite this URL:
Gagandeep K, Neeru B, Pal AJ, Singh SK, Parkash KA. Consent for anesthesia . Ain-Shams J Anaesthesiol [serial online] 2016 [cited 2019 Jun 20];9:6-11. Available from: http://www.asja.eg.net/text.asp?2016/9/1/6/178872


  Introduction Top


Anesthesiologists are not only responsible for administering anesthesia during surgery, but are also primary clinicians in ICU and pain clinics. They are also a part of trauma and resuscitation teams; they perform various invasive interventions such as epidural analgesia and nerve blocks for pain relief. These all procedures have their own inherent risks. In modern scenario, more and more complex surgeries are being performed on sick and elderly patients, which carry high risk. With growing trend in medical negligence cases being registered in courts, obtaining valid informed consent has become a fundamental principle of modern anesthesia practice. For this purpose, reliance on hand-written notes or consent for anesthesia as a part of surgical consent form lacks sufficient detail to assist the anesthesiologist in proving his or her side in medicolegal cases. There is a need for consent form, which permits an anesthesiologist to direct the patient's attention to an appropriate technique with full information, allows sufficient time to review it, and then take autonomous decision. Adopting a standardized anesthesia-specific consent form will achieve the above objective. The present article will review the process of informed consent, legal implications associated with consent, and how to avoid them. We will also try to give recommendations to formulate an anesthesia consent form, which covers every aspect of the process of consent.

What is consent?

Consent is a state of mind, a decision by a patient. It allows an autonomous patient who has the capacity to think, decide, and act on the basis of such thought independently and without hindrance, to define and protect his or her own interests and to control bodily privacy [1],[2] . Consent has three aspects: ethical [3] , professional [4],[5],[6] , and legal [1] .

Well-informed consent is a relatively new concept. Before 1957, doctors usually obtained assent [7] where no information regarding risk and benefit was needed by the patient; only a reasonable standard of care was expected from the doctor [8],[9] . With the passage of time, there occurred commercialization of medical profession, which led to the loss of patient's trust in their doctors. Bringing the medical profession under consumer protection act [10] in some of the countries such as India further eroded the mutual trust. In the changed circumstances, from legal point of view, assent was not enough to protect doctors from litigation cases. In the 1950s, the word informed consent came into existence [11] . A judgment was given in Salgo [12] case in 1957, which formed the basis of informed consent. Hence, the present form of consent has three components: information regarding the risk and benefits of the procedure, decision making by the patient after fully understanding the given information, and full autonomy of the patient regarding his or her decision.

Information

The first duty of the anesthesiologist is to give complete information to the patient regarding the procedure. This includes fasting, effects of premedication, connection to monitors, intravenous lines, injections, endotracheal intubation, regional blocks, postoperative pain and its management, need for blood transfusion, and any other invasive intervention. Commonly occurring side effects or complication of the selected procedure should be explained - for example, nausea, vomiting, postdural puncture headache, etc. Thereafter, rare but serious complications should be explained - for example, awareness during anesthesia, any numbness after nerve block, etc. Patients should be given full opportunity to ask questions to clear their doubts, and answers should be given with honesty. Patients who are at higher risk of anesthesia due to their comorbidities should be told about the nature and extent of risk involved.

There is no well-defined disclosure technique available. From legal point of view, full information should be disclosed to the patient [13] . Ethically, it is not possible, as the patient would be burdened with whole information and would not be able to decide properly [14] . The depth of information should vary with the level of risk involved. For example, parents of a child undergoing circumcision under general anesthesia should be told about the common risks only, but if the same child undergoes hepatoduodenal anastomosis, then even the risk of death under anesthesia should also be disclosed as 'less likely but more dangerous risk'. Another method is where the patient controls the extent of disclosure [15],[16],[17] . After giving initial information about commonly occurring risks, option is left with the patient if he wants to know more. 'The acid test is whether a serious complication is likely enough to occur that a reasonable person might choose to refuse the procedure or seek an alternative' [18] .

Exception to this is therapeutic privilege, where an anesthesiologist withholds information because he believes that disclosure could harm the patient. Requirement for evoking therapeutic privilege is very rigorous, for example, very ill patients, emotionally unstable patients who are not able to make a rational decision after disclosure, can cause hindrance in their treatment, or disclosure would cause psychological damage to the patient.

Giving information in the preoperative area or when the patients are wheeled to the operation theater is not recommended. Written information should be in patient's vernacular language and if the patient is not able to read then a translator should be available.

Medical negligence can be charged if the anesthesiologist provides insufficient information to allow a patient to make treatment decision, and as a result foreseeable injury occurs even in the absence of treatment error [19] . Courts determine the depth of information provided, by materiality [20] and causation [21] . Negligence can be charged even if the patient was not given enough time for decision making or just a paper document was given to sign without proper disclosure [22] .

Decision-making capacity

Participation of patients in their own care decisions is called decision-making capacity [23] . Consent is valid only when it is given voluntarily by an appropriately informed person, who has the capacity to express an informed choice. A voluntary decision is made by the patient in the absence of external influences. Sometimes, doctor provides limited choice regarding treatment options according to his or her expertise, from which patient has to choose; hence, the mere concept of voluntariness is lost [24] .

Patient is assumed to be competent to make decisions, if he understands, retains, and uses the given information [23] , and if he fails either one of the above components then he is not competent [25] . Adult patients above the age of 16 or 18 years (in some countries it is 16 years and in some it is 18 years) are supposed to be competent. Exceptions are minor (below 16 or 18 years of age), mentally challenged, unconscious, very sick, or those patients with temporarily altered sensorium (under the effect of sedation or general anesthesia). Decision-making capacity is judged by the anesthesiologist himself.

Legally, consent is valid when it is given voluntarily without coercion [26] . Refusal of treatment by a competent patient even if it results in patient's death has to be respected [25] .

In case of minor, parents are the decision makers, and if parents are not available then the legal guardians appointed by the parents or court act as decision makers. Minor can give consent for some procedures but anesthesiologist has to judge whether the child has enough intelligence and understanding to appreciate what is proposed [27] . Sometimes, parents refuse the required treatment of their child; in that case application can be moved to the court to seek intervention. However, if the treatment is life saving and very urgent, then treatment can be initiated without parental authorization and even without court orders.

In case of mentally incapacitated patients, if procedure is urgently required, consent is not mandatory, taking into account the best interest of patient. Certification from an authorized practitioner regarding patient's lack of capacity to consent and that the proposed treatment would alleviate or improve the patient's condition should be taken [28] . Anesthesiologist can also seek assistance from psychiatrist or law in deciding whether patient is competent to give consent or not.

In case of patients where decision-making capacity is temporarily disturbed, decision for an intervention can be deferred to later date if possible, but if it is an emergency, then treatment can be given without consent in the best interest of patient; however, it is prudent to consult next of kin before giving treatment. Detailed notes regarding the reasons for which treatment was given without consent should be mentioned [29] .

In terminally ill patients, proxy-decision makers appointed by the previously competent patient can make decisions. If the patient has no proxy-decision maker, then court-appointed persons can make treatment decisions, other than life-sustaining decisions. Advance directives given by the patient voluntarily when he or she was competent should be followed, unless there is evidence that patient may have changed his mind [30]. Advance directives cannot authorize doctors to perform anything outside the law or compel them to carry out a specific type of treatment [31],[32] .

Autonomy

It is the right of the informed patient to follow a self-chosen plan voluntarily. It empowers the patients to remain in control of their fate and bodily integrity, free from unwarranted interference from others. It also improves patient satisfaction and more favorable medical outcome [15] . Voluntary decision of the patient may be influenced by coercion, manipulation, or persuasion. Coercion and manipulation are unethical. Persuasion is acceptable technique where patient's decision can be influenced by legitimate arguments. Doctor can give advice to the patient according to his expertize but the final decision lies with the patient. Thus, the competent patient has every right to refuse treatment known as informed refusal [33] . Sometimes, patient needs an opinion of their anesthesiologist to make decision - it is called paternalism [34] . Decision will not be fully autonomous as it is based on the advice of treating doctor [24] . A competent patient has every right to refuse or choose treatment even if it is life saving, and doctor can be held liable if patient's autonomy is not respected.

The process of valid informed consent should conclude when the patient himself requests or authorizes an anesthesiologist to perform a specific procedure. At the end, anesthesiologist should confirm it by asking, 'Do you wish to follow this plan?' Aim of taking consent is to seek consensual compromise for a planned procedure.

Documentation

Record of complete discussion with the patient should be documented. Agreement of the patient to a particular technique or refusal should be noted. If patient wants to reverse his previous documented decision, then written details of the discussion and final decision should be noted. If the treatment was given without consent, then the reasons behind it should be documented. Mostly, medical negligence cases are registered after a time lapse; written documentation will help the anesthetist to prove his point as proper recall of the past events may not be possible.

Consent in special situations

Critical care and emergency

The process of consent in ICU is not different from the general population. Critically ill patients have the right to make their treatment decisions. Difficulty arises when patients temporarily lose their capacity to make decisions. In these situations, anesthesiologist has the right to treat in the best interests of the patient after discussing with fellow practitioners and patient's relatives. If there is any dispute among the relatives or attending doctor, then legal help may be sought. Doctors should follow the advance directives, if given by the patient [31] . Emergency treatment also requires informed consent, if patient is competent enough to make decision. If patient is not competent to decide, then the reasons behind it should be noted and treatment can be initiated in the best interest of the patient.

Jehovah Witness

Anesthesiologist should respect patient's religious beliefs, the most prominent being the Jehovah's Witness where blood and blood product transfusion is prohibited. When these patients come for anesthesia, detailed information regarding the need for blood transfusion and the various options to reduce blood loss should be discussed [35],[36] . Use of synthetic colloid solution, blood component therapy, erythropoietin, and autologous blood transfusion must be discussed [37] . Full autonomy of adult competent patient should be respected, whether he refuses or chooses blood transfusion even if it is life saving. It is very crucial to document what interventions are acceptable to the patient and what are not acceptable. If pregnant women, minor, or incompetent patient refuses blood transfusion as life-saving treatment, courts can intervene and mandate blood transfusion [36] . Similarly, when incompetent patient comes in emergency, if the patient had advance directives regarding blood transfusion, then patient's wishes should be respected. However, if there are no advance directives and family members refuse transfusion, then the legal and ethical consensus leans toward blood transfusion.

Obstetric patients

Anesthesiologists are involved in providing pain relief during labor and giving anesthesia for cesarean section. Problem arises when anesthesiologist is called at a very short notice or when the patient is in labor or under the effect of opioids and is not able to give consent regarding analgesia/anesthesia. In obstetric patients, treatment plans should be discussed at the time of antenatal visits and patient's decision for a proposed plan should be documented [38] . Detail of the proposed plan should again be explained to the patient before initiating it, even if she is not able to understand what is being told. If a pregnant patient makes unusual wishes or harmful decisions, it should be documented. If refusal of the treatment or intervention may result in harm to the unborn baby, then legal help can be taken.

Chronic pain treatment

Various interventions performed for relief of chronic pain syndromes or cancer pain are usually not life-saving procedures. Hence, before performing them, full information of the benefits and risks should be told. Patients should be allowed to ask questions and make their decisions without unrealistic expectations. Consent can be taken for full course of treatment, rather than asking patient's choice at every visit.

Research work and teaching

Clinical research on patients can be carried only after the approval of research ethical committee (REC). It gives approval after considering the validity of research and welfare and dignity of patient [39] . Consent for research is obtained in the same manner where the patient has full right to refuse or choose to participate in the research.

General principles followed to avoid negligence case

The basis of a good physician-patient relationship is mutual trust. In the past, patients trusted their doctor's advice and believed that their doctor would always act in their best interests. Now, the situation has changed. Patients are more informed and more attention is given to the patient's autonomy. According to law, any treatment, investigation, or physical contact with the patient without consent may amount to assault and it is an offense, which may constitute serious professional misconduct. Anesthesiologist has certain limitations in establishing a trusting relationship with their patients. Most of the time, anesthesiologist meets the patient in the preoperative room just before procedure. Enough time is not available to make a healthy discussion. In the recent years, several developments have prompted the anesthesiologist to revisit the word 'consent.' Obtaining well-informed consent forms an integral part of healthy doctor-patient relationship. Preanesthetic clinics with conducive environment should be set up for to-and-fro discussion. Anesthesiologist should make efforts to reduce patient anxiety, enhance confidence, and encourage maximum patient participation in decision making [40] . Reciprocal truth telling, sharing patient's fears and concerns, and answering honestly improves patient's trust. Irrespective of the information that patient shares, it should be kept confidential and should not be shared with others without consent [41] . Anesthesiologist must recognize and support patient's religious beliefs. If there are multiple anesthesia providers, then patient should be told who will be giving premedication, who will be administering anesthesia, and who will take care of postoperative pain. Anesthesiologist should be aware of the concept of advance directives and should follow them. Sometimes, patients make wrong decisions and if anesthesiologist does not feel morally or ethically capable of providing care, then he should make a reasonable effort to find another competent and willing anesthesia provider for the patient, before refusing patient care. A physician has an obligation to the patient and cannot be abandoned until the relationship is terminated [42] . Written documentation citing the cause for terminating patient care should be performed. Withdrawing from the care of patient is ethically and legally wrong and may be held guilty of abandonment.

Following guidelines should be followed while taking informed consent.

  1. It should be for a specific procedure.
  2. It should be given voluntarily by a competent patient.
  3. Common, less common, and less likely complication should be explained.
  4. Risk related to patient's comorbidites should be explained.
  5. Adequate time should be given to read and understand the consent form.
  6. Honest answers should be given to patient's questions.
  7. Patient should be given the choice to choose from various anesthetic options given.
  8. Whole discussion and patient's decision for intervention should be precisely documented in patient's vernacular language.
  9. Patient should sign the form after carefully going through it.

  Conclusion Top


Anesthesiologist has a legal duty to provide relevant information to the patient regarding interventions and allow them to make voluntary decision without any external influence. They should respect patient's decision, as this helps to build a trusting relationship. This will improve patient's welfare and medical beneficence. In case of legal proceedings, a well-informed written consent form will help anesthesiologist to provide an evidential defense against allegations of nonconsensual treatment.

Recommendations for anesthesia consent

form and how to take consent


When the patient is registered for surgery, a leaflet having all the relevant information regarding proposed technique should be given to the patient. Sufficient time should be given to read it carefully so that patient can clear his doubts if any, on meeting his anesthesiologist.

Leaflet: It should have details of the three anesthetic options available: general, regional, or monitored sedation, from which patient can choose after knowing the risks and benefits of each technique. Common, uncommon, and very rare side effects should be explained in the leaflet.

When patient comes to preanesthetic clinic, anesthesiologist should introduce himself or herself to the patient. Detailed history about past illness, medication history, allergic reaction to any drug, any loose teeth, caps, crowns, or dentures should be taken. Patient should be told that, despite the best care and attention, some complications of anesthesia may occur and some serious consequences can occur due to your pre-existing illness or previous history of anesthetic problems. Proposed anesthetic technique depending on the health of the patient and the nature and duration of surgery should be told. Whole discussion should be clearly documented.

Consent form: I, ---------, have read the above consent form and have asked the anesthetist about everything that I did not understand. I consent to an alternative technique of anesthesia if required as deemed appropriate by my anesthetist. I understand the importance of providing my anesthetist with complete medical history, need to disclose previous medication taken, alcohol intake, and any illegal drugs that may give rise to serious complications. I understand the risks, alternatives, and expected results of the anesthetic technique and that I had ample time to ask questions and to consider my decision.




  Acknowledgements Top


Conflicts of interest

There are no conflicts of interest.

 
  References Top

1.
White SM, Baldwin TJ. Consent for anaesthesia. Anaesthesia 2003; 58:760-764.  Back to cited text no. 1
    
2.
White SM, Seery J. Consent: the law and ethical considerations. Anaesth Intens Care Med 2009; 10:111-114.  Back to cited text no. 2
    
3.
White SM. Consent for anaesthesia. J Med Ethics 2004; 30:286-290.  Back to cited text no. 3
    
4.
General Medical Council. Seeking patient′s consent: the ethical considerations (1998). Available at: http://www.gmc-uk.org/guidance/library/consent.asp . [Accessed 2014 July 13]  Back to cited text no. 4
    
5.
Department of Health. Reference guide to consent for examination or treatment. Available at: http://www.gov.uk/government/uploads/system/uploads/attachment_data/file/138296/dh_103653__1_.pdf. [Accessed 13 May 2014]  Back to cited text no. 5
    
6.
7.
Manson NC, O′Neill O. Rethinking informed consent in bioethics. Cambridge: Cambridge University Press; 2007.  Back to cited text no. 7
    
8.
Faden RR, Beauchamp TL. A history and theory of informed consent. New York: Oxford University Press; 1986. 23-143.  Back to cited text no. 8
    
9.
Leake CD. Percival′s medical ethics. Baltimore: Lippincott Williams & Wilkins; 1927.  Back to cited text no. 9
    
10.
Consumer Protection Act as valid in India (1986), section 2(1)(o).  Back to cited text no. 10
    
11.
Mills DH. Whether informed consent? JAMA 1974; 229:305-310.  Back to cited text no. 11
    
12.
Gild WM. Informed consent: a review. Anesth Analg 1989; 68:649-653.  Back to cited text no. 12
    
13.
Maclean A. From sidaway to pearce and beyond: is the legal regulation of consent any better following a quarter of a century of judicial scrutiny? Med Law Rev 2012; 20:108-129.  Back to cited text no. 13
    
14.
Lynoe N, Hoeyer K. Quantitative aspects of informed consent: considering the dose response curve when estimating quantity of information. J Med Ethics 2005; 31:736-738.  Back to cited text no. 14
    
15.
Waisel DB, Truog RD. The benefits of the explanation of the risks of anesthesia in the day surgery patient. J Clin Anesth 1995; 7:200-204.  Back to cited text no. 15
    
16.
Farnill D, Inglis S. Patients′ desire for information about anaesthesia: Australian attitudes. Anaesthesia 1993; 48:162-164.  Back to cited text no. 16
    
17.
Lankton JW, Batchelder BM, Ominsky AJ. Emotional responses to detailed risk disclosure for anesthesia, a prospective randomized study. Anesthesiology 1977; 46:294-296.  Back to cited text no. 17
    
18.
Hirsh HL. CH Wecht, editor. A visitation with informed consent and refusal. Legal medicine. Charlottesville, VA: Michie; 1995. 147-204.  Back to cited text no. 18
    
19.
Bianco EA, Hirsch HL. SS Sanbar, A Gibofsky, MH Firestone, TR LeBlang, editors. Consent to and refusal of medical treatment. Legal medicine. 3rd ed. St Louis: Mosby-Year Book; 1995. 274-296.  Back to cited text no. 19
    
20.
Foley HT, Dornette WHL. WHL Dornette, editor. Consent and informed consent. Legal issues in anesthesia practice. Philadelphia: FA Davis; 1991. 81-89.  Back to cited text no. 20
    
21.
Liang BA. What needs to be said? Informed consent in the context of spinal anesthesia. J Clin Anesth 1996; 8:525-527.  Back to cited text no. 21
    
22.
Clark SK, Leighton BL, Seltzer JL. A risk-specific anesthesia consent form may hinder the informed consent process. J Clin Anesth 1991; 3:11-13.  Back to cited text no. 22
    
23.
Beauchamp TL, Childress JF. Principles of biomedic ethics. 4th ed. New York: Oxford University Press; 1994. 44-119.  Back to cited text no. 23
    
24.
O′Neill O. Paternalism and partial autonomy. J Med Ethics 1984:10:173-178.  Back to cited text no. 24
    
25.
Jane Fortin: Children rights and the developing law. Adolescent decision makeup and health care. 3rd ed. Cambridge 2009; page 153.  Back to cited text no. 25
    
26.
Jason Payne-James, Ian Wall. 2nd ed. Cambridge University Press, New York. 2004; page 137.  Back to cited text no. 26
    
27.
Judtith Hendrick, Lynne Wigens: Law and ethics. Nelson Thomes Ltd, UK. 2004; page 265.  Back to cited text no. 27
    
28.
John Keown: The law and ethics of Medicine: essays on the inviolability of human life. Oxford, UK. 2012; page XV.  Back to cited text no. 28
    
29.
Moye J, Karel MJ, Azar AR, Gurrera RJ. Capacity to consent to treatment: empirical comparison of three instruments in older adults with and without dementia. Gerontologist 2004; 44:166-175.  Back to cited text no. 29
    
30.
Stephen Bonner, Mark Carpenter, Emilio Garcia. Care of critically ill medical patient. Elsevier, China, 2007; page 381.  Back to cited text no. 30
    
31.
Treatment and care toward end of life. Available at: http://www.gmc-uk.org/End_of_life.pdf_32486688.pdf. [Accessed 13 May 2014]  Back to cited text no. 31
    
32.
Penelope Weller: New law and ethics in mental health advance directions: the convention on the right of persons with disabilities and the right to choose. Rontledge, New York; 2013.  Back to cited text no. 32
    
33.
Kerridge I, Lowe M, Mitchell K. Competent patients, incompetent decisions. Ann Intern Med 1995; 123:178-181.  Back to cited text no. 33
    
34.
Habiba M. Examining consent within the patient doctor relationship. J Med Ethics 2000; 26:183-187.  Back to cited text no. 34
    
35.
George GA, Dean BA: Pediatric anesthesia. Blackwell publishing, UK, 2012, 5th ed.  Back to cited text no. 35
    
36.
Rothenberg DM. The approach to the Jehovah′s Witness patient. Anesth Clin North Am 1990; 8:589-607.  Back to cited text no. 36
    
37.
Benson KT. The Jehovah′s Witness patient: considerations for the anesthesiologist. Anesth Analg 1989; 69:647-656.  Back to cited text no. 37
    
38.
OAA/AAGBI guidelines for obstetric anaesthetic services (2013). Available at: http://www.aagbi.org/sites/default/files/obstetric_anaesthetic_services_2013.pdf http://www.aagbi.org/sites/default/files/obstetric_anaesthetic_services_2013.pdf. [Accessed 13 May 2014]  Back to cited text no. 38
    
39.
Briefing Pack for Research Ethics Committee Members. Using evidence in health and social care. London: Department of Health; 1997.  Back to cited text no. 39
    
40.
Perkins HS. JH Stein, editor. The fiduciary concept: a basis for an ethics of patient care. Internal medicine. St Louis: Mosby-Year Book; 1994; 2858.  Back to cited text no. 40
    
41.
Ubel PA, Zell MM, Miller DJ, Fischer GS, Peters-Stefani D, Arnold RM. Elevator talk: observational study of inappropriate comments in a public space. Am J Med 1995; 99:190-194.  Back to cited text no. 41
    
42.
Council on Ethical and Judicial Affairs, American Medical Association. Code of medical ethics: current opinions with annotations. Chicago: American Medical Association; 1994.  Back to cited text no. 42
    




 

Top
 
 
  Search
 
Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
Access Statistics
Email Alert *
Add to My List *
* Registration required (free)

 
  In this article
   Abstract
  Introduction
  Conclusion
  Acknowledgements
   References

 Article Access Statistics
    Viewed1118    
    Printed9    
    Emailed0    
    PDF Downloaded182    
    Comments [Add]    

Recommend this journal


[TAG2]
[TAG3]
[TAG4]