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Thursday, July 15, 2010


Do you think the PAC clinics have started disappearing? Are they essential for pre anaesthetic evaluation? This issue has recently been emerged as a topic for discussion in some Anaesthesia conference. Eventhough at first thought,  you may feel this is an absurd statement,those who support this notion give some valid reasons. They strongly argue that ASA 1 and 2 patients are not benefitted from PAC as they are in good health or in mild systemic illness which is well controlled.These patients can be directly admitted to the ward by surgeons or they can report as day care cases, which will reduce the work strain of staff and doctors and  that this is cost effective.This method also helps to reduce the waiting time of patients in PAC clinic. For ASA 3 and 4 pre anaesthetic check up and follow up are done in ward  on a multidisciplinary approach.

The author somehow feels this is inappropriate. A well conducted PAC clinic is essential for the proper assessment of all types of patients including ASA 1 and 2. Now office based  and day care surgeries are commonplace everywhere and patients seen in PAC clinic can be sent to office or day care suite direct,on the day of surgery without getting them admitted to the hospital.Even in a properly conducted preanaesthetic check up, the clinician missed certain vital informations in ASA 1 and 2 cases, which led to serious intra operative complications.Thus the  necessity of a thorough and proper evaluation aided by available investigations is stressed.. Look into some of the following clinical scenario.

Scenario 1,
A10 year old ASA 1, boy was posted for sebaceous cyst excision under GA. He was induced with propofol fentanyl  and sevoflurane. LMA was inserted for airway control  and left him on spontaneous. Soon after induction of anaesthesia he developed hypertension inspite of adequate depth of anaesthesia.The search for a possible cause could not reveal anything.A post op follow up by echocrdiogram  and CT scan revealed mild co arctation of aorta which remained undetected. In this case a preop BP check was not performed by the anaesthetist, which was not practised as routine for ASA 1 children, in that hospital.The child had no intraoperative adverse outcome as it was a minor surgery without much hemodynamic disturbance.
Scenario 2,
A 23 year old patient was posted for D&C .The PAC was unremarkable except for a tachycardia of rate 110/mt.A referral to physician was made from the surgical side for a possible cause, and a diagnosis, anxiety induced tachycardia was made.The anaesthetist gave fitness as ASA 1 and  advised sedative premedication.  On the day of surgery the case was reviewed  and the mild proptosis with tachycardia made the second anaesthetist to think of the possibility of a thyrotoxicosis, and blood sample was sent for thyroid function tests.Meanwhile the patient had a bout of bleeding and was taken to OT for emergency curettage.A thyroid function test result after 1 hour showed severe thyrotoxicosis but patient sustained surgery without any adverse outcome.
Scenario 3,
A 16 year old boy was sent  for pre anaesthetic check up for excision of dermoid cyst of scalp. He had no past h/o illness  and was given fitness by anaesthesia.General anaesthesia was given and he was intubated. The tumour was tightly adherent to the scalp and the surgeon was not able to remove it completely. On extubation the boy showed muscular rigidity, hypertonicity followed by generalised convulsions for 1 minute. The child remained un conscious  and reintubated. Blood sample sent for electrolytes measurement. A CT scan done which showed erosion of the dermoid into the skull vault with intracranial extension.The child was shifted to a tertiary centre for neurosurgical evaluation.

Thus running a PAC clinic is a must for the proper evaluation and follow up of all pre operative patients irrespective of their ASA status, and this evaluation should include complete physical and laboratory examination with inter departmental referrals, on an outpatient basis.

The realm of anaesthesiology is now expanding. Apart from their role as perioperative physicians,    anaesthesiologists are actively involved in trauma management, intensive care and pain management. Several hospitals have already integrated pain clinics to the PAC clinic for the effective delivery of pain management services. Some of this clinics are even equiped with facilities to institute nerve blocks under monitoring and even minor surgeries.Thus hospital admission and and the health risks associated,such as nosocomial infections, work load on the staff etc. can be reduced  and this is found to be cost effective. Thus the need for running a full fledged PAC clinic is emphasized.

Consultation by an anaesthesiologist is essential for the proper assessment of a patient prior to anaesthesia for surgery or other procedures. The purpose is to make sure that the patient is in  optimal physical state for anaesthesia and surgery and is not affected by systemic illness, and if at all affected, stable in a controlled state.The visit also helps in risk stratification according to various scoring systems  and ASA physical status. Anaesthesia management is planned and informed consent for the anaesthesia procedure is obtained during the visit after fully explaining the advantages and disadvantages of a particular anaesthetic procedure. Certain guidelines have been published by various societies and associations for a proper conduct of pre anaesthetic check up.  The notable one include the canadian society recommendations.[1]
Test Indications :

Complete blood count:   Major surgery requiring group and screen or group and match, Chronic cardiovascular, pulmonary, renal or hepatic disease,Malignancy ,known or suspected Anemia, Bleeding diathesis or Myelo-suppression,Patient less than 1 year of age.
Sickle cell screen: Genetically predisposed patient (hemoglobin electrophoresis if screen is positive)
International normalized ratio (INR), : (Activated partial thromboplastin time) Anticoagulant therapy
Bleeding diathesis,Liver disease,
Electrolytes and creatinine levels: Hypertension ,Renal disease,Diabetes Pituitary or adrenal disease, Digoxin or diuretic therapy, or other drug therapies affecting electrolytes
Fasting glucose level: Diabetes,  (should be repeated on day of surgery)
Pregnancy:  (Beta-HCG),   Women who may be pregnant.
Electro-cardiograph: Heart disease, Hypertension, Diabetes,Other risk factors for cardiac disease (may include age) Subarachnoid or Intracranial hemorrhage, Cerebrovascular accident, Head trauma
Chest radiograph: Cardiac or pulmonary disease,Malignancy .

Fasting policies: Must vary, to take into account of age and pre-existing medical conditions and should apply to all forms of anesthesia, including monitored anesthesia care. Emergent or urgent procedures should be undertaken after considering the risk of delaying surgery versus the risk of aspiration of gastric contents. The type and amount of food ingested should be considered in determining the duration of fasting. Before elective procedures, the minimum duration of fasting should be

  • 8 hours after a meal that includes meat, fried or fatty foods
  • 6 hours after a light meal (such as toast and a clear fluid), or after ingestion of infant formula or nonhuman milk
  • 4 hours after ingestion of breast milk
  • 2 hours after clear fluids.
Premedication, when indicated, should be ordered by the anesthesiologist. Orders should be specific as to dose, time and route of administration.

According to National Institute of Clinical Excellence UK gudelines, the preop investigations are planned with due consideration of their ASA physical status and type of surgery. According to the type of surgery different grades have been proposed.[2]
Grade 1: (minor) Excision of lesion of skin; drainage of breast abscess
Grade 2: (intermediate) Primary repair of inguinal hernia; excision of varicose vein(s)of leg; tonsillectomy / adenotonsillectomy; knee arthroscopy
Grade 3: (major) Total abdominal hysterectomy; endoscopic resection of prostate; lumbar discectomy; thyroidectomy
Grade 4:  (major+) Total joint replacement; lung operations; colonic resection; radical neck dissection
Grade >4:  Neurosurgery,  Cardiovascular surgery 
ASA Grades:
ASA Grade 1 “Normal healthy patient” (that is without any clinically important comorbidity and without clinically significant past/present medical history)
ASA Grade 2 “A patient with mild systemic disease”
ASA Grade 3 “A patient with severe systemic disease”
ASA Grade 4 “A patient with severe systemic disease that is a constant threat to life”
For eg  ASA 1 patient for  grade 1 surgery  less than 16 years of age  no investigations are required  but for adults(>16 years)   ECG is required above 40 years, CBC and renal function required above 60 years and urine analysis for all. CXR is not at all required.For ASA 2,3 and 4 patients for grade2,3 and 4 surgeries more detailed evaluation and risk strtification are necessary.  A detailed information can be obtained from  ref  [2] 
In general the following recommendation which is widely followed in UK can be used for requesting pre op investigations, which are evidence based.
Urine analysis: All patients,for sugar, blood and protein
ECG: Age >50  years, History of heart disease, Lung disease or Hypertension
Complete blood count:  Males greater than 40 years, All females,All major surgery and when Anemia is suspected
Renal function tests: Age >60 years, All major surgery, Diuretic drugs,  Previous renal disease
Blood glucose: Diabetic patients, Glycosuria
Coagulation screen: History of bleeding tendency
Sickle cell screening: Races where the disease is common and status unknown, if positive Hb electrophoresis should be done
Pregnancy: Whenever there is a chance or suspicion of pregnancy
CXR: Not routine   H/o Cardiac or pulmonary disease or h/o Tuberculosis. H/o Malignancy
HIV status: Not routine
Thus for  children  posted for tonsillectomy, the essential investigations include Hb% and blood grouping  and sickle cell status if  there is a racial significance or predilection  and nothing else. For circumcision in ASA 1 no investigations are necessary.
The domain of PAC clinic has extended outside the anaesthetist's rooms. With the advent of third generation communication means and high speed wireless access, the concept of a wireless PAC clinic has emerged. This adds to the importance of running a well equipped PAC clinic with all facilities to deliver proper pre anaesthetic care and other services, including pain management.The components of a wireless PAC clinic include mobile phones equipped with 3G facilities,computers and high speed internet connection. A wireless communication is established between patients and physician and data related to history, investigations, and  examination findings can be transferred. Advise regarding medications, consent, and other pre operative instructions can be sent to patients.The physician can verify all investigation reports and previous examination findings. CT or Ultrasound scan procedures can be visualised in real time. The exercise tolerance can be assessed using a web cam. The respiratory and heart sounds can be  heard through a microphone attached to patient's chest. This process is highly useful for ASA 1 and 2 patients and for patient referral from peripheral hospital to tertiary centres.The need for patient education on computers and internet and the cost of implementation are the limiting factors.[3]

1)  The Canadian Anesthesiologists' Society; http://www.cas.ca/members/sign_in/guidelines/practice_of_anesthesia/default.asp?load=preanesthetic
2) National Institute of Clinical Excellence,UK; www.nice.org.uk/nicemedia/live/10920/29090/29090.pdf
3) An article on wireless prescription by Jay Srage, Qualcomm; Arab health issue 2, 2010
4) Image courtesy: ipcl.ee.queensu.ca/information.html 


dr.sandeep said...

highly useful information it is beyond doubt that PAC clinics are essential for pre anaesthetic check up


dr.Anil safaya ibri hospital made his comment on face book and says PAC clinics are highly useful and pre anaesth checks should not be taken lightly.

dr.gangadhar said...

it is proved that PAC clinics are helpful in avoiding un anticipated intra op complications

Sadasiv Swain said...

Right from residency days one needs to examine many patients in ASA Gr-1 &2 status, so that when he/she becomes a qualified anesthesiologist the critical grades will be easily discernible and will not be escaping examination.