Hypertension & Anaesthesiologist

PLAN OF THIS PRESENTATION:
1. Introduction :
a. What is hypertension: Definition as per JNC 7 and NICE?
b. Hypertension & Anaesthesiologist : Issue of concern
c. Hypertension & Anaesthesia: Issues unanswered : raised in questions below.
Let there be no dilemma: Clarity of thoughts and correct decision making differentiates a good anaesthesiologist from a bad anaesthesiologist.
2. Question –Answer session: Just Answers as far as possible.
3. Discussion : Justify each answer



QUESTION AND ANSWERS:
(For explanation see the discussion / text)
1. What level of BP is acceptable for elective surgery in a treated hypertensive, and why?
Answer : ≤ 140/90
2. A 55y M, undiagnosed hypertensive posted for laproscopic cholecystestomy, has a BP of 160/110 mm Hg on the OT table. There is no obvious evidence of end organ damage. Would you postpone surgery?
Answer : Confirm that the BP is actually 160)/ 110
a. Rule out equipment fault etc
( see ‘Taking the measurement’ in discussion)
b. Give IV sedation and recheck.
i. If still high : postpone and investigate
ii. If acceptable limits (≤ 140/90) : proceed with surgery
3. What level of BP is acceptable for elective surgery in an untreated hypertensive and why?
Answer : ≤ 140/90 (See text)
4. Would you start treatment yourself or refer the patient to a cardiologist? If yes, what drug will you start and when would you take up the patient for surgery?
Answer: No. Will refer to a physician/ cardiologist as this facility is available in our centre. ( see ‘ when to refer’ in text)
5. What is the significance of ‘white coat’ hypertension?
Answer : See text

6. What are the risk factors in taking up an untreated/poorly controlled hypertensive?
Answers: Isolated hypertension: minimal risks.
Accompanying end organ damage: higher risks.
7. What agent do you use to attenuate the stress response of laryngoscopy and intubation?
Answers: Any one or combination of these agents used in our centre.
• IV Propofol bolus, IV Thiopentone bolus, IV fentanyl (0.5-1ug/kg), , IV Lignocaine ( 1.5mg/kg), supplementation with inhalation agent ( halothane, isoflurane, sevoflurane) , before laryngoscopy.
• Hypotensive agents like nitroglrcerin, sodium nitroprusside, beta blockers
(metaprolol, esmolol) and calcium channel blockers (diltiazem, nifedipine) been used in resistant cases.
8. Hypertensive patient for orthopaedic lower limb surgery, would you prefer regional anaesthesia or GA? Any particular choice of anaesthetic agents in GA?
Answer: Would decide on case-to-case basis. Can give general anaesthesia or regional anaesthesia.
Would prefer epidural or combined spinal epidural (CSE) technique due to added advantage of post-operative analgesia.
9. Would you give regional anaesthesia to a beta blocked patient?
Answer: Yes. However, do not forget to ‘pre-load’ the patient to avoid hypotension after SAB/ epidural.
Also ensure availability of atropine and isoprenaline to counter intractable bradycardia.
10. Patient develops a BP of 180/120 mm Hg intraoperatively. The depth of anaesthesia and analgesia are adequate. How would you manage?
Answer : (See discussion below)
a. If accompanied with tachycardia: IV beta blockers: metaprolol or esmolol.
b. No tachycardia: Nitroglycerin or sodium nitropruside infusion.
11. Patient requiring urgent surgery has a BP of 200/130 mm Hg. How will you achieve rapid control?
Answer: see discussion below
a. If concomitant tachycardia: IV beta blockers: metaprolol / esmolol.
b. No tachycardia: Nitroglycerin or sodium nitropruside infusion.


Preoperative Hypertension: The dilemma to postpone elective surgery
Introduction:
How often have we asked ourselves: - shall I go ahead and anaesthetize this patient with uncontrolled hypertension, or should I postpone surgery until the arterial pressure is controlled? Does the benefit of preoperative arterial pressure control justify the inconvenience and financial consequences of postponing surgery? Are patients with uncontrolled hypertension at an increased perioperative risk? Are there any data on which I can base my decision?
Even if a patient carries the diagnosis of hypertension and takes antihypertensive therapy, the hypertension may be poorly controlled. Additionally, long-standing hypertension may result in end-organ damage in the heart, brain, and kidneys, which might be unrecognized until the time of the preoperative evaluation. Accordingly, the preoperative evaluation is a unique opportunity to identify patients with hypertension and evaluate them for appropriateness of therapy and the presence of end-organ damage. Given the current pressures to proceed expeditiously with scheduled surgery, it is important for the physicians evaluating such patients to understand the implications of managing hypertensive patients in peri-operative period.
Then there are other issues of concern for the anaesthesiologist himself. Palmer aptly stated that ‘my concerns regarding preoperative hypertension not only extend to the patient, but also to me!’ Thus, for a risk-averse anaesthetist, the presence on the list of a patient whose blood pressure (BP) is elevated may lead to increase in anxiety of the anaesthetist .
One may not be always so risk averse; but it is scientific enough to state that anaesthesia for elective procedures should be as risk free as possible.
The subsequent paragraphs provide a review / compilation of literature on this subject and its relevance to the anaesthesiologist. It aims to suggest ‘How far to go in not going too far’ in control of hypertension in the peri-operative period.
The strong direct relationship between systolic and diastolic BP and cardiovascular risk has been well-established . This relationship is graded, consistent, and predictive .Therefore, to more effectively identify and treat individuals with hypertension, it is helpful to review the definitions of the term hypertension.
The definition and meaning of the term “Hypertension” has been modified over the years. With the availability of new and better drugs, the treatment regimens have also changed.
The revised classification system is based on the Seventh Report of the Joint National Committee on the Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC 7), which also assimilates findings from new hypertension studies and clinical trials, and includes clearer, more concise guidelines for clinicians. Hypertension is defined in the guidelines as "a systolic blood pressure (SBP) higher than 140 mmHg or a diastolic blood pressure (DBP) higher than 90 mmHg. Diagnosis is based on the average of two or more readings taken at each of two or more visits after an initial screening." The JNC 7 guidelines classify hypertension into three groups within that definition, each with pharmaceutical implications. The JNC 7 classifications of hypertension are: prehypertension (SBP 120 to 139 mmHg, DBP 80 to 89 mmHg); stage 1 hypertension (SBP 140 to 159 mmHg, DBP 90 to 99 mmHg); and stage 2 hypertension (SBP 160 mmHg or greater, DBP 100 mmHg or greater).
Doctors have, however, again proposed a new definition of hypertension, taking the emphasis away from the blood pressure numbers and placing it on a person's overall risk of heart disease and stroke.
American Society of Hypertension Writing Group suggests the new definition as "Hypertension is a progressive cardiovascular syndrome arising from complex and interrelated etiologies. Early markers of the syndrome are often present before blood pressure elevation is sustained; therefore, hypertension cannot be classified solely by discrete blood pressure thresholds. Progression is strongly associated with functional and structural cardiac and vascular abnormalities that damage the heart, kidneys, brain, vasculature, and other organs and lead to premature morbidity and death."
There are definitive precautions for BP measurement which must be followed before labeling a patient as hypertensive. Unfortunately, more often than not, these precautions are not followed in the pre-anaesthesia visit. In India, the anaesthetist may be the primary physician detecting higher values of BP. Is every high value of BP hypertension? There are well established guidelines in the west which can be exteneded to our environment. It would be appropriate to state one these guidelines (UK guidelines):
• Healthcare professionals taking blood pressure measurements need adequate initial training and should have their performance reviewed periodically.
• Devices for measuring blood pressure must be properly validated, maintained and regularly recalibrated according to manufacturers’ instructions.
( This review of performance of the personnel and the validation of the equipment is mostly not done in our Indian setups)
Taking the measurements:
• Where possible, standardise the environment when measuring blood pressure: the environment should be relaxed, quiet and warm, and the patient seated with their arm outstretched and supported.
• If the first measurement exceeds 140/90 mmHg, take a second confirmatory reading at the end of the consultation if possible.
• Measure blood pressure on both of the patient’s arms and use the arm with the higher value as the reference arm for future measurements.
• If the patient has symptoms of postural hypotension (falls or postural dizziness), measure blood pressure while they are standing.
• To identify hypertension (persistent raised blood pressure, above 140/90 mmHg), ask the patient to return for at least two more appointments; check blood pressure twice on each occasion, under the best conditions available.
• Take measurements at monthly intervals – but if the patient has severe hypertension re-evaluate him or her earlier.
• Routine use of automated ambulatory blood pressure monitoring or home monitoring devices in primary care is not recommended.
APPROACH TO A HYPERTENSIVE PATIENT:
Patients who are diagnosed to be hypertensive should be properly evaluated and treated. Drug therapy reduces the risk of cardiovascular disease and death. Various guidelines on the management of hypertension have been issued by various scientific organizations. The most recent guidelines are the UK guidelines published in June 2006 which are discussed. These guidelines are produced by the British Hypertension Society (BHS), which is a group of specialists in high blood pressure and the National Institute for Health and Clinical Excellence (NICE). They set out a step-by-step approach to prescribing medicines for health professionals and their patients to use. This means that from now on people who have high blood pressure will be treated according to one national guideline and will have their medicines chosen based on their age and their ethnic group.
If one is already receiving treatment for high blood pressure, then the new guidelines may mean a change in your treatment, particularly if one is currently taking a beta-blocker. It is important to stress that there is no urgent need for anyone to change treatment, and that any changes that need to be made can be done as part of your routine treatment at the next usual appointment.
An important change in this new set of guidelines is that they have been agreed by both NICE and the BHS. This means that, for the first time, there is just one very clear pathway to follow when choosing medicines.
The new NICE guidelines recommend treating hypertension using the algorithm below, with an ACE inhibitor in younger, non-black patients, or a calcium-channel blocker or diuretic in older or black patients. Second-line therapy is to add a calcium-channel blocker or diuretic for patients already on an ACE inhibitor, and adding an ACE inhibitor for those on a calcium-channel blocker or diuretic. The recommended third-line therapy is a combination of an ACE inhibitor, calcium-channel blocker and diuretic. If further treatment is required, NICE now recommend adding an alpha-blocker, betablocker or further diuretic.
(In India, there is no uniformity in approach to management of hypertension. Therefore, in the pre-operative evaluation of patients scheduled for surgery, one comes across varied treatment regimens of hypertension that are being followed.)



N.B. Beta-blockers are not preferred first line therapy unless patient is ACE inhibitor or ARB intolerant, or is pregnant.
When to refer:
Refer immediately if the patient has signs of:
– accelerated (malignant) hypertension (blood pressure more than 180/110 mmHg with signs of papilloedema and/or retinal haemorrhage)
– suspected phaeochromocytoma (possible signs include labile or postural hypotension, headache, palpitations, pallor and diaphoresis).
Consider referral if:
– the patient has unusual signs and symptoms
– the patient has signs or symptoms suggesting a secondary cause
– the patient’s management depends critically on the accurate estimation of their blood pressure
– the patient has symptoms of postural hypotension, or a fall in systolic blood pressure when standing of 20 mmHg or more.
Drug therapy reduces the risk of cardiovascular disease and death
• Offer drug therapy to patients with:
– persistent high blood pressure of 160/100 mmHg or more
– persistent blood pressure above 140/90 mmHg and raised cardiovascular risk (10-year risk of cardiovascular disease of at least 20%, existing cardiovascular disease or target organ damage).
General issues when prescribing:
• Aim to reduce blood pressure to 140/90 mmHg or less, adding more drugs as needed, until further treatment is inappropriate or declined.
• Offer patients with isolated systolic hypertension (systolic blood pressure more than 160 mmHg) the same treatment as patients with both raised systolic and diastolic blood pressure.
• Offer patients older than 80 years the same treatment as other patients aged 55 or older – take account of any co-morbidity and other drugs they are taking.
• Prescribe drugs taken only once a day if possible.
• Prescribe non-proprietary drugs if these are appropriate and minimise cost.
• Give information about the benefits and side effects of drugs so that patients can make informed choices.
Beta-blockers may still be used in the following groups of people:
• Younger women who could get pregnant (This is because the usual choice of
medication for younger people, an ACE inhibitor, can be harmful in pregnancy)
• Those who cannot take an ACE inhibitor or an angiotensin receptor blocker
• Who have had a previous heart attack or who have chest pain (angina)




HPERTENSION & ANAESTHESIOLOGIST: WHY BE CONCERNED?
Hypertension affects one billion individuals worldwide. Pooling of epidemiological studies in India shows that hypertension is present in at least 25% urban and 10% rural adult subjects in India.
Why should anaesthetists remain wary of hypertension? For at least three reasons:
(i) Hypertensive patients tend to be more haemodynamically unstable and prone to myocardial ischaemia in the perioperative period.
(ii) Hypertension is a major risk factor for coronary artery disease, congestive heart failure, and renal and cerebrovascular disease. Any of these factors increase the likelihood of perioperative myocardial infarction or death.
(iii) Hypertension is associated with dyslipidaemia, diabetes, and obesity, and the side-effects of drugs needed to treat these diseases.
The risk of cardiovascular events in the general population increases steadily with increases in arterial pressure. The individuals at greatest risk of suffering a cardiovascular event because of hypertension are those with the highest arterial pressures. This is illustrated in Figure 1, which documents the association between systolic hypertension and deaths as a result of coronary artery disease. The highest risk of death is seen in patients with systolic arterial pressures of greater than 180 mm Hg. However, the greatest number of excess deaths (calculated as the difference between the number of deaths that would be expected from coronary artery disease on the basis of the rate in the group with a systolic arterial pressure of less than 110 mm Hg and the number of deaths actually recorded) is seen in the largest group of subjects. That is, those with systolic arterial pressures of between 140 and 149 mm Hg. Hence, medical guidelines for the treatment of hypertension emphasize the treatment of mild to moderate hypertension. As stated above, the British Hypertension Society Guidelines on the management of hypertension use a threshold of 140/ 90 mm Hg for the initiation of treatment.
How can we safely anaesthetize hypertensive patients? :
The anaesthetist while managing a hypertensive patient is apprehensive of the risk / likelihood of peri-operative cardiac event.
Essential elements of perioperative management include careful preoperative evaluation, tight perioperative arterial pressure and heart rate control, cardiac protection, and a well-trained, experienced and dedicated anaesthetist.
In the west, preoperatively, it may be helpful to contact the referring general practitioner to obtain more realistic arterial pressure values than the ones measured at hospital admission, which might overestimate the long-term arterial pressure level referred to as `white coat' or `isolated office hypertension'. In India, getting this information is usually not easy.
Hypertension-induced target organ damage should be sought and, if present, be evaluated and appropriately treated. Assessment of physical exercise tolerance is crucial. In special situations, postponement of surgery hypertensive patients may be justified to allow for additional preoperative cardiac testing. In the context of isolated hypertension, however, additional testing is rarely indicated and should only be considered in patients scheduled for high-risk surgery (e.g. major vascular surgery). If in addition to an elevated arterial pressure, signs of coronary artery (e.g. ischaemic electrocardiographic changes) or renal disease (e.g. elevated serum creatinine) discovered, coupled with poor exercise tolerance and an intermediate- or high-risk surgical procedure, then additional preoperative cardiac testing should also be considered. However, such testing should only be performed the results are likely to have an impact on perioperative management (e.g. before coronary revascularization, modification of perioperative monitoring, changes in medical management).
Perioperative arterial pressure and heart rate control is essential in hypertensive patients. While hypertensive peaks need to be avoided, profound (relative) hypotension, especially when associated with baroreflex-mediated tachycardia, can be equally detrimental. Review of literature reveals various studies and guidelines on the subject of hypertension and peri-operative outcome. The two important ones are stated here.
The review by Howell and colleagues in their study “Hypertension, hypertensive heart
disease and perioperative cardiac risk” implies that patients are unlikely to die perioperatively from a preoperatively elevated arterial pressure level per se but, more likely, from underlying hypertension-associated comorbidities and, possibly, from inadequate perioperative management because of lack of understanding of the
pathophysiology of hypertension. Clearly, the difference between an adverse and favourable outcome can be achieved not by treatment of numbers (in this case arterial
pressure values), but rather by the appropriate perioperative management of the disease entity. Obviously, hypertension only one of many risk factors that determine perioperative management and outcome–and, apparently, not the most important one. There is general agreement based on the evidence presented by Howell and colleagues that patients with mild and moderate hypertension and no evidence of coronary artery disease or end-organ damage may safely undergo surgery without delay. In contrast, for patients with severe hypertension, the data are insufficient to allow an unequivocal recommendation as to what constitutes the optimal approach. Any recommendation to postpone elective surgery for the purpose of preoperative arterial pressure control must be balanced against the urgency and benefit of the planned operation; must take into account that arterial pressure should be corrected slowly, and that up to 2 months may be required to reverse some of the hypertension induced cardiovascular changes; and must acknowledge the fact that data are lacking to support such practice.
The ACC / AHA published the “ACC/AHA Guideline Update for Perioperative Cardiovascular Evaluation for Noncardiac Surgery—Executive Summary” in 2002. They
provide a framework for considering cardiac risk of noncardiac surgery in a variety of patient and surgical situations. The purpose of preoperative evaluation was not simply to give medical clearance but rather to perform an evaluation of the patient’s current medical status; make recommendations concerning the evaluation, management, and risk
of cardiac problems over the entire perioperative period; and provide a clinical risk profile that the patient, primary physician, anesthesiologist, and surgeon can use in
making treatment decisions that may influence short and long-term cardiac outcomes.
The ACC/ AHA guidelines include uncontrolled systemic hypertension as a ‘Minor Clinical Predictor’ of Increased Perioperative Cardiovascular Risk in their stepwise bayesian strategy. The suggested approach is shown as under:


What is pertinent to note is that a decision to accept a patient detected as hypertensive in pre-operative evaluation rests not only on ‘ BP reading’ per say, on other factors : functional status as assessed by Duke’s Activity status index, associated cardiac risk factors and surgical risk associated with the procedure.
Surgery-specific cardiac risk of noncardiac surgery is related to 2 important factors: the type of surgery itself and the degree of hemodynamic stress associated with the procedures.
As per the ACC / AHA practice guidelines, Stage 3 hypertension (systolic blood pressure greater than or equal to 180 mm Hg and diastolic blood pressure greater than or equal to 110 mm Hg) should be controlled before surgery. In many such instances, establishment of an effective regimen can be achieved over several days to weeks of preoperative outpatient treatment. If surgery is more urgent, rapid-acting agents can be administered that allow effective control in a matter of minutes or hours. Beta-blockers appear to be particularly attractive agents. Continuation of preoperative antihypertensive treatment through the perioperative period is critical.
In general, indications for further cardiac testing and treatments are the same as those in the nonoperative setting, but their timing is dependent on such factors as the urgency
of noncardiac surgery, the patient’s risk factors, and specific surgical considerations.
Preoperative testing should be limited to circumstances in which the results will affect patient treatment and outcomes. A conservative approach to the use of expensive tests and treatments is recommended.
The results of noninvasive testing in these patients can be used to determine the need for additional preoperative testing and treatment. In some patients with documented CAD, the risk of coronary intervention or corrective cardiac surgery may approach or even exceed the risk of the proposed noncardiac surgery. This approach may be appropriate, however, if it significantly improves the patient’s long-term prognosis.
White Coat hypertension (WCH) & Anaesthesia:
The rationale for the use of ambulatory blood pressure monitoring (ABPM) has been the subject of critical reviews and published guidelines. Perhaps the most important and challenging finding to emerge from ambulatory blood pressure research has been the detection of "white coat" hypertension (also known as isolated clinic hypertension) in about 20% of subjects with repeatedly elevated casual blood pressure readings taken in the doctor's clinic. The condition can only be detected by ABPM or self-monitoring, and there are no specific predisposing factors. For people with white coat hypertension and no evidence of cardiovascular disease or comorbidities such as diabetes or renal disease, most experts agree that the best policy is to monitor their clinic blood pressure regularly, with self-monitoring at home, and repeat ABPM at one- to two-yearly intervals.
The importance of continued monitoring is borne out by the evidence now emerging that white coat hypertension may not be an entirely innocent phenomenon.
In a 10-year follow up study, it is concluded that WCH is a cardiovascular risk factor that WCH patients have an unfavourable metabolic risk profile, and that WCH is a prehypertensive state. Based on these results it is recommended that WCH patients are followed carefully with regular checks of BP and complete cardiovascular risk profile and that treatment with antihypertensive medication is initiated when WCH develops into established hypertension.
So what should an anaesthetist do in such situations? It is suggested that a BP record be maintained during follow-up.
If hypertension persists:
• Treat it as per the guidelines stated above.
• Determine the MET status
• Assess for other risk factors and metabolic profile.
If BP record is normal:
• Caution the patient and advice him to continue long term follow up



Intra-operative Hypertension:
Intraoperative hypertension is common and has many causes. It is usually rapidly and successfully treated by anaesthetists. However, when it is severe, no cause is evident, or it fails to respond to routine measures, it has the potential to cause morbidity and even mortality in susceptible patients.A rapid appropriate response by the anaesthetist to this problem is therefore required
Pre-existing hypertension, particularly if untreated, increases the likelihood of Intraoperative hypertension and of complications, as has previously been reported. Hypertension is common.
Hypertension and tachycardia under anaesthesia have been shown to be independent risk factors for poor outcomes, particularly after long procedures.


CAUSES OF INTRA_OPERATIVE HYPERTENSION:
Causes of spurious intra-operative hypertension:
• Calibration drift of invasive device
• Sphygmomanometer cuff herniation
• Calibration error of non-invasive device
Equipment related causes of intraoperative hypertension :
• Ventilation problem
• Stuck valve
• Hypoventilation
• Soda lime exhaustion
• Endobronchial intubation
Drug related causes of Intraoperative hypertension:
• Vasopressor administration:
o inadvertent, by anaesthetist
o by a surgeon
• IV adrenaline with local anaesthetic
• Anaesthetic failure:
o failure to deliver volatile agent_
o failure to deliver nitrous oxide
• Unknown`

Review of literature reveals that intra-operative hypertension not responding to an increase in anaesthetic depth has been treated with a variety of parenteral agents. The commonly used drugs are listed in Table below. The choice of the agent depends upon the severity, acuteness and cause of hypertension, the baseline cardiac function, the heart rate and the presence of bronchospastic disease.
Agent Dosage range Onset Duration
Nitroprusside 0.5-1o ug/kg/min 30-60 secs 1-5 min
Nitroglycerin 0.5-10uk/kg/min 1 min 3-5 min
Esmolol 0.5mg/kg over 1 min
50-300ug/kg/min 1 min 12-20 min
Labetelol 5-20 mg 1-2 min 4-8 hours
Propranolol 1-3 mg 1-2 min 4-6 hours
Nifedipine sublingual 10mg 5-10min 4 hours


SPINAL ANAESTHESIA IN HYPERTENSIVE PATIENTS:
There are a number of potential problems associated with the hypertensive patient having spinal anaesthesia. If left ventricular hypertrophy is present, then it is important to maintain an adequate perfusion pressure in order to ensure adequate myocardial perfusion.
Autoregulation limits in organs such as the brain and the kidney may have become reset to higher levels and, thus, these organs will cope poorly with low perfusion pressure. In addition, hypertension is associated with cerebrovascular disease and, if carotid artery stenosis is present, this mandates prompt and relatively aggressive support of blood pressure.
In patients with controlled hypertension receiving thoracic epidural anaesthesia, clinical experience suggests that risks are similar to the non-hypertensive population. Patients with uncontrolled hypertension are also prone to a greater lability of blood pressure and may have a relative hypovolaemia (contracted circulating blood volume) which can be unmasked by spinal blockade.
REGIONAL ANAESTHESIA IN PATIENT ON BETA BLOCKERS:
• Beta-blockers suppress the compensatory tachycardic response to hypotension associated with SAB or haemorrhage, but should generally be continued for prevention of perioperative myocardial ischaemia.
• Beta-blockers may decrease blood flow to the liver; therefore, they may also decrease the metabolism of amide-type anesthetics and may cause serum levels of the anesthetic to increase. So be careful of the total dose of local anaesthetic agent administered.


ATTENUATION OF INTUBATION RESPONSE:
Tracheal intubation leads to hypertension and tachycardia. Various agents have been used for attenuation of this response. These include lignocaine (1.5mg/kg), remifentanyl (1ug/kg), alfentanyl (10-20ug/kg) or fentanyl (0.5-1ug/kg) before laryngoscopy. Hypotensive agents like nitroglrcerin, sodium nitroprusside, beta blockers and calcium channel blockers have also been shown to effectively attenuate transient hypertensive response to laryngoscopy and intubation.

Conclusion:
Chronic hypertension may go undetected for a long time, and may be found for the first time during routine preoperative assessment. Modern anaesthesia provided by a well trained, experienced and dedicated anaesthetist offers sufficient perioperative cardiac protection to make cancellation of surgery for the sole purpose of controlling preoperative hypertension unnecessary under most circumstances. Appropriate evaluation and intervention can be expected to improve peri-operative and long-term outcome.
When confronted with uncontrolled preoperative hypertension, we need to remain wary but not become unduly alarmed.





FIGURE 1


Important References:
1. National Institute of Health & Clinical Excellence (NHS): “Hypertension: management of hypertension in adults in primary care.” Quick reference guide Issue date: June 2006
2. Howell SJ, Sear JW, Foe»x P. Hypertension, hypertensive heart disease and perioperative cardiac risk. Br J Anaesth 2004; 92:570±83
3. ACC/AHA Guideline Update for Perioperative Cardiovascular Evaluation for Noncardiac Surgery—Executive Summary A Report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee to Update the 1996 Guidelines on Perioperative Cardiovascular Evaluation for Noncardiac Surgery).
(Assessed at : http://circ.ahajournals.org/cgi/content/full/105/10/1257)


Dr R. Chawla