GENERAL DATA

This is a case of SB, a 29 year old multigravida who came in due to increased abdominal girth.

PREANESTHETIC ASSESSMENT

History :

3 years prior to admission, patient was pregnant for her first child , an ultrasound was done revealing an incidental finding of ovarian cyst on the left side . She was advised by her obstetrician to come back after 3 months for another ultrasound.The patient didn’t comply until 2 years prior to admission, patient claimed to be asymptomatic , no bleeding ,pain and increased in abdominal girth .An ultrasound was done revealing a mass on the left side that increased in size and a thick cervix. However due to financial constraints she decided to wait for another year to have the mass removed.

1 year prior to admission, patient decided to have the mass removed however, she got pregnant for her second child . She and her obstetrician decided to removed the mass once she deliver by caesarean section . 8 months prior to admission, the patient delivered via normal spontaneous vaginal delivery hence, the surgery was deferred and was rescheduled. This time, patient noticed vaginal spotting and pain on the left lower quadrant. No consultation done and no medications taken until 3 weeks prior to admission, patient noticed an increased in abdominal girth , increased pain intensity on the left side with pain scale of 8 over 10 and menorrhagia soaking 5 pads/ day.This prompted consultation with her attending physician ,transvaginal/ transabdominal scan was done revealing the left ovary is transformed into a cystic structure , anechoic measuring 15.2 x 15.1 x9.6 cm with septations (septa 0.22 cm) , thick walled 0.43 cm suggestive of an ovarian new growth and was advised for surgery hence this admission.

PAST MEDICAL HISTORY

The patient is not a known diabetic , hypertensive or asthmatic .

She had a herniorraphy under local anesthesia when she was 10 years old and claimed to to have no known food or drug allergies.

FAMILY HISTORY

Hypertension and diabetes mellitus were prominent on her maternal side while cancer particularly breast cancer was present on her paternal side.Aside from these,there are no other heredofamilial diseases were reported on both sides.

PERSONAL / SOCIAL HISTORY

SB was born and raised in Davao City and is currently teaching in an elementary school. . She got married last 2010.

Her diet mostly consists of carbohydrates, proteins with moderate amounts of fat.She is not a smoker and does not drink alcoholic beverages.

GYNECOLOGIC HISTORY

Patient had her menarche at 12 years old. Subsequent menstrual periods were regular lasting for 3 days moderate in quantity associated with occasional dysmenorrhea . 3 weeks prior to admission , patient noticed menorrhagia soaking 5 pads/ day.Patient had her sexual debut at 20 years old with 1 sexual partner who eventually became her husband.

OBSTETRIC HISTORY

The patient is multigravida G2P2 (2002). Her last menstrual period was last November 18, 2013. She claimed to have urinary tract infection during her first pregnancy and treated with unrecalled antibiotics. Her two pregnancies were delivered via normal spontaneous vaginal delivery ,full term,male , approximately 2.8 kilograms and 2.9 kilograms.

REVIEW OF SYSTEMS

GENERAL(-) easy fatigability

ENDOCRINE SYSTEM(-) thyroid problems, (-) neck surgery, (-) heat and cold intolerance

SKIN(-) pruritus

HEAD(-) dizziness, (-) headache

EYE(-) pain, (-) excessive lacrimation

EAR(-) tinnitus

NOSE(-) persistent stuffiness, (-) nasal congestion, (-) postnasal drip

MOUTH(-) bleeding gums, (-) dyspnea

THROAT(-) odynophagia, (-) hoarseness

NECK(-) neck surgery, (-) nuchal rigidity, (-) limited motion

BREAST(-) breast pain, (-) abnormal discharge

CARDIAC(-) nocturnal dyspnea, (-) murmurs

PERIPHERAL VASCULAR(-) claudication

GASTROINTESTINAL(-) change in bowel habits

PULMONARY(-) hemoptysis, (-) asthma

GENITO-URINARY(-) dysuria, (-) flank pain

HEMATOPOIETIC(-) easy brusing

MUSCULAR(-) limited ROM

NEUROLOGIC(-) change in orientation

PHYSICAL EXAMINATION

GENERAL

The patient was examined in supine position conscious, coherent and responsive .

VITAL SIGNS

Her vital signs were within normal range.

BP: 110/80 mmHg; PR: 91 bpm; RR: 20 bpm; temperature: 36.5 ˚C

Weight: 63 kg; Height: 152 cm

SHEENT:

SKIN:

I – fair complexion, no lesions/scars, no palmar erythema, nails without clubbing and cyanosis

PA – moist and warm with good skin turgor. No palpable lesions, tenderness, lumps noted

HEAD:

I – hair is black in color, no lesions noted

A – non-palpable lymph nodes

EYES:

I – anicteric sclerae, pink palpebral conjunctivae

EARS:

I – no lumps, lesions noted

PA – non-tender and mobile external ear

NOSE:

I – symmetric, no swelling noted, nasal septum at midline

PA – frontal and maxillary sinuses are not tender

MOUTH:

I – no lesions noted, tongue and vulva at midline, no tonsilar enlargement noted

-mouth ulcers

NECK:

I – supple, no nuchal rigidity and gross thyromegaly, trachea at midline, no lesions noted

BREAST:

I – no redness/discharge noted

PA – no mass palpated, non-tender

CHEST/LUNGS:

I – no scars/ lesions noted

PA – non-tender

PE – resonant

A – vesicular breath sounds in most areas without adventitious sounds

CARDIOVASCULAR:

I – adynamic precordium

PA – symmetric pulses, capillary refill time < 2 sec

A – no murmurs noted. PMI at 5th ICS, left MCL

ABDOMEN

I – no lesions noted, (+) abdominal distention. Abdominal girth 20cm

A – normoactive bowel sounds at 5 bowel sounds per minute

PE – dullness at RUQ, the rest is tympanic

PA – non-tender, no palpable abdominal mass

EXTERNAL GENITALIA

I – no lesions/scars noted, no enlargement and swelling noted, with watery vaginal discharge

SPECULUM EXAM

(-) pooling of clear watery discharge at the posterior vaginal fornicus.

(-) fluid per cervical os

EXTREMITIES

I – no lacerations, fissures noted

PA – warm to touch, no edema noted

MUSCULOSKELETAL

I – normal muscle strength of 5/5, normal ROM, no deformities, atrophy and swelling noted

MENTAL STATUS

The patient is appropriately dressed. She is in supine position and with good grooming. Cooperative with the interviewer. Mood is congruent with affect and appropriate. Thought process is coherent, no suicidal ideations or plans. Memory is intact to remote, recent and immediate recall.

CRANIAL NERVES

I – able to smell

II – pupils equally round and reactive to light and accommodation

III – exhibit normal EOM

IV – able to move eyeballs obliquely

V – blinks whenever sclera was lightly touched

VI – able to move eyeballs laterally

VII – able to perform different facial expressions

VIII – able to hear loud and soft spoken words

IX – able to elicit gag reflex

X – able to swallow without difficulty

XI – able to shrug shoulders against resistance

XII – able to protrude tongue at midline and move it side to side

MOTOR:

Muscle strength 5/5

COORDINATION:

Finger to nose test intact

SENSORY:

Pinprick: intact

Light touch, position and vibration: intact

REFLEX:

Negative primitive reflex

Corneal reflex elicited

DIAGNOSIS :

G2P2 (2002) Ovarian new growth left probably benign

PLANNED PROCEDURE :

EXLAP, salphingo- oophorectomy

Day of surgery : November 28,2013

Age : 29 years old

Weight : 63 kilograms

Height :152 cm

BMI : 28 kg/m2 overweight

Airway assessment :

Normal

Mouth opening : 3 fingers

Thyromental distance >6 cm

Full neck movement

Mallampati : I

Laboratory results :

IMMUNOLOGY :

Ca 125 : 21 u/ml

AFP 10.110

SGPT (ALT) : 14 u/L

CBC :

Hemoglobin: 142 g/L

Hematocrit: 0.44

RBC: 4.90

WBC: 7.05

Neutrophils : 58

Lymphocytes : 33

Monocytes : 6

Eosinophils: 2

Basophils : 1

Platelet count: 364

Transvaginal/transabdominal scan:

Normal sized retroverted uterus with no myometrial lesion

Endometrium is slightly thickened at 0.98 cm and intact

The right ovary is normal in size and echotexture

The left ovary is anterior to the corpus and is transformed into a cystic structure , anechoic measuring 15.2 x 15.1x 9.6 cm with septations (0.22 cm) thick walled 0.43 cm suggestive of an ovarian new growth, (+) minimal free fluid in cul de sac Sassone score 8, cut off 9 for malignancy)

PT : 14.7 seconds

APTT: 29.4 seconds

Chemistry

Sodium : 135 mmol/L

Creatinine 77 umol/L

Potassium :3.80 mmol/L

Maximum allowable blood loss: 1900

ASA status : 2 for BMI of overweight

ANESTHESIA PLAN : Sub- arachnoid block 20 mg + 0.2 morphine sulfate

CASE DISCUSSION

A pre-anesthesia evaluation must be performed for each patient, prior to any inpatient or outpatient surgery or diagnostic or therapeutic procedure requiring anesthesia services, by a person qualified to administer anesthesia

Thyromental distance is a measurement used to determine the horizontal distance between the thyroid prominence and the inner surface of the mandible when the head and neck are fully extended and the mouth is closed.This assessment is currently used to aid in the evaluation of the airway before endotracheal intubation.

Preinduction measurement of thyromental distance is important, because during direct visual laryngoscopy(DVL) the tongue is displaced by the laryngoscope into the thyromental distance space. 1 If the TMD is short, there is less space for tongue compression by the laryngoscope blade. In that case, visualization of the glottis and/or vocal cords can be difficult or impossible, potentially resulting in failed intubation. A TMD of less than 6 cm is generally accepted as a predictor for difficult DVL

Another method to predict the ease of intubation is the mallampati classification. A high Mallampati score (class 3 or 4) is associated with more difficult intubation as well as a higher incidence of sleep apnea.[2] In many ways it assesses the height of the mouth; the distance from the tongue base to the roof of the mouth, and therefore the amount of space in which there is to work. It is an indirect way of assessing how difficult an intubation will be; this is more formally scored using the Cormack-Lehane classification system, which describes what you actually see on direct laryngoscopy.

The Mallampati score is assessed by asking the patient (in a sitting posture) to open his/her mouth and

protrude the tongue as much as possible. The anatomy of the oral cavity is visualized; specifically, whether the base

of the uvula, faucial pillars (the arches in front of and behind the tonsils) andsoft palate are visible. Scoring may be

done with or without phonation. Depending on whether the tongue is maximally protruded and/or the patient asked to

phonate, the scoring may vary.

Modified Mallampati Scoring:[3]

Class I: Soft palate, uvula, fauces, pillars visible.

Class II: Soft palate, uvula, fauces visible.

Class III: Soft palate, base of uvula visible.

Class IV: Only hard palate visible

Based on the diagragm above, my patient belong to mallampati class 1.

The Cormack and Lehane classification (1984) is the original, and most widely used classification of laryngeal view

and is shown in Fig 1.

Grade 1Most of the glottis is visible

Grade 2

At best almost half of the glottis is seen, at worst

only the posterior tip of the arytenoids is seen

Grade 3Only the epiglottis is visible

Grade 4No laryngeal structures are visible

Table 1 Cormack and Lehane classification

The grade is the best view achieved

External manipulation and backward, upward, rightward pressure (BURP ) may be used

Another thing to consider is The American Society of Anesthesiologists (ASA) Physical Status classification system was initially created in 1941 by the American Society of Anesthetists, an organization that later became the ASA.The purpose of the grading system is simply to assess the degree of a patient’s "sickness" or "physical state" prior to selecting the anesthetic or prior to performing surgery. Describing patients’ preoperative physical status is used for recordkeeping, for communicating between colleagues, and to create a uniform system for statistical analysis. The grading system is not intended for use as a measure to predict operative risk.

The modern classification system consists of six categories, as described below:

ASA PS 1

Normal healthy patient

No organic, physiologic, or psychiatric disturbance; excludes the very young and very old; healthy with good exercise tolerance

ASA PS 2

Patients with mild systemic disease

No functional limitations; has a well-controlled disease of one body system; controlled hypertension or diabetes without systemic effects, cigarette smoking without chronic obstructive pulmonary disease (COPD); mild obesity, pregnancy

ASA PS 3

Patients with severe systemic disease

Some functional limitation; has a controlled disease of more than one body system or one major system; no immediate danger of death; controlled congestive heart failure (CHF), stable angina, old heart attack, poorly controlled hypertension, morbid obesity, chronic renal failure; bronchospastic disease with intermittent symptoms

ASA Patients with severe Has at least one severe disease that is poorly controlled or at end

PS 4systemic disease that is a constant threat to life

stage; possible risk of death; unstable angina, symptomatic COPD, symptomatic CHF, hepatorenal failure

ASA PS 5

Moribund patients who are not expected to survive without the operation

Not expected to survive > 24 hours without surgery; imminent risk of death; multiorgan failure, sepsis syndrome with hemodynamic instability, hypothermia, poorly controlled coagulopathy

ASA PS 6

A declared brain-dead patient who organs are being removed for donor purposes

Replacing Blood Loss

"Ideally, blood loss should be replaced with crystalloid or colloid solutions to maintain intravascular volume (normovolemia) until the danger of anemia outweighs the risks of transfusion. At that point, further blood loss is replaced with transfusions of red blood cells to maintain hemoglobin concentration (or hematocrit) at that level. For most patients, that point corresponds to a hemoglobin between 7 and 10 g/dL (or a hematocrit of 21-30%). Below a hemoglobin concentration of 7 g/dL, the resting cardiac output has to increase greatly to maintain normal oxygen delivery" (Morgan & Mikhail, 1996).

Estimating blood loss***

Dry sponges

4x4hold~10mLbloodRay-techs~10-20mLbloodLap sponges ~ 100 mL blood

Pediatric cases should have sponges & gauze weighed for blood loss**

Blood loss replacement***

Replace 1 mL blood with:

3mLcrystalloid(i.e.NS,Dextrose,LR)1mLcolloid(i.e.albumin**,Hespan®,Dextran®)

1mLwholeblood1 mL PRBC

Subarachnoid (spinal) block is a safe and effective alternative to general anesthesia when the surgical site is located on the lower extremities, perineum (eg, surgery on the genitalia or anus), or lower body wall (eg, inguinal herniorrhaphy). Because of the technical challenges of readily identifying the epidural space and the toxicity associated with the large doses of local anesthetics needed for epidural anesthesia, spinal anesthesia was the dominant form of neuraxial anesthesia well into the 20th century.

Subarachnoid block can be used the sole source of anesthesia. Alternatively, spinal and epidural anesthesia can be used jointly, taking advantage of the qualities of both techniques: the rapid, dense sensorimotor blockade of a spinal anesthetic and the opportunity to redose the patient with an epidural catheter anesthetic.

Spinal anesthesia produces intense sensory and motor blockade as well as sympathetic blockade. As opposed to epidural anesthesia, in which medications are instilled outside the dura mater, the goal of spinal anesthesia is to instill the desired medications into the cerebrospinal fluid (CSF). The sensorimotor block produced requires smaller doses of local anesthetics (hence, local anesthetic toxicity is rarely a concern) and is often more dense in character.

Comparison with epidural anesthesia may be informative. For instance, brief periods (less than 24 hours) of postoperative analgesia can be facilitated by adding an opioid to the local anesthetic injected into the cerebrospinal fluid. Prolonged postoperative analgesia is best ensured by insertion of an epidural catheter, using an opioid and local anesthetic combination infused continuously over the first few postoperative days.

Comparative Benefits of Subarachnoid and Epidural Anesthesia

Subarachnoid Anesthesia Epidural Anesthesia

Volume of drug administered Small Large

Onset Fast Slowa

Density of blockade Usually dense Potential for patchy sensory blockade

Opportunity for redosing No, unless a catheter was inserted (rare)

Yes, as catheter was inserted

Systemic blood levels of injected medications

Negligible May be significant

Anatomic region Lumbar Any vertebral level

Ability to augment postoperative analgesia

Minimal (< 24 hours) Excellent and for a number of days

a Onset varies with choice of local anesthetic.

Indications

Spinal anesthesia is a safe and effective alternative to general anesthesia when the surgical site is located on the lower extremities, perineum (eg, surgery on the genitalia or anus), or lower body wall (eg, inguinal herniorrhaphy). Cesarean deliveries are routinely performed under spinal anesthesia, as are total hip arthroplasty and total knee arthroplasty.[3]

As in the case of our patient her operation is salpingo-oophorectomy which is the removal of the fallopian tube (salpingectomy) and ovary (oophorectomy).

Advantages include avoidance of general anesthesia and the airway management concerns that accompany general anesthesia. However, that is not to suggest that spinal anesthesia is always the best course in a patient likely to have difficulties with endotracheal intubation. All patients with difficult airways, no matter what anesthetic plan is chosen, should have a well thoughtout plan for airway management, should it be needed.

Additional benefits may include reducing the metabolic stress response to surgery, reduction in blood loss, decrease in the incidence of venous thromboembolism, reduction in pulmonary compromise (particularly in patients with advanced pulmonary disease), and the ability to monitor the patient’s mental status.

Contraindications

Strong contraindications include patient refusal, lack of patient cooperation, difficulties with positioning, and increased intracranial pressure. Other contraindications include situations that require some risk-benefit analysis include hypovolemia, coagulation disturbances, stenotic valvular disease, bacteremia, and infection at the site of needle insertion.

Spinal anesthesia has also been noted to result in symptomatic deterioration in patients with multiple sclerosis.[4] Patients with chronic low back pain may decline spinal anesthesia out of concerns for increased low back pain. Performing spinal anesthesia in patients with degenerative lumbar spine disease or a prior history of lumbar surgery may prove technically difficult, but these are not necessarily contraindications.

Allergy to local anesthetics may also be a contraindication, but true allergies are usually found with ester-based local anesthetics (eg, tetracaine), not the amide-based local anesthetics (eg, bupivacaine), so finding a suitable local anesthetic is not challenging.[5]

Although one-shot injection techniques are the norm, continuous spinal anesthesia has enjoyed periods of popularity while also being demonized. In the early 1990s, spinal microcatheters (27-G) were introduced but were followed by an increased incidence of postoperative cauda equina syndrome.[6] In cases in which cauda equina syndrome developed postoperatively, microcatheters were used; in response to an unsuitable rise in anesthetized dermatomal levels, unusually large of doses of local anesthetics (usually lidocaine) were administered to effect a sufficient spinal anesthetic.

What may have happened was that insufficient turbulence was created through injection through the microcatheter, the local anesthetic pooled distally in the lumbar intrathecal space (below the natural lumbar lordosis),

and with repeated local anesthetic doses, administered in hopes of advancing the dermatomal level of local anesthetic effect, toxic local anesthetic levels were created in the region of the cauda equina.

Continuous spinal techniques may be regaining a slow resurgence in popularity, but patients should be carefully chosen. Instead of microcatheters, larger conventional epidural catheters should be used. Because of the larger rent in the dura, postdual puncture headache is an increased risk; therefore, patients who are less likely to have postdual puncture headache, such as older patients, are better candidates. The wisdom that excessive doses of local anesthetics are best not injected into the intrathecal space has been hard earned.[7]

Physiology of Spinal Anesthesia

Local anesthetic solution injected into the subarachnoid space blocks conduction of impulses along all nerves with which it comes in contact, although some nerves are more easily blocked than others.

There are three classes of nerve: motor, sensory and autonomic. The motor convey messages for muscles to contract and when they are blocked, muscle paralysis results. Sensory nerves transmit sensations such as touch and pain to the spinal cord and from there to the brain, whilst autonomic nerves control the caliber of blood vessels, heart rate, gut contraction and other functions not under conscious control.

Generally, autonomic and pain fibers are blocked first and motor fibers last. This has several important consequences. For example, vasodilation and a drop in blood pressure may occur when the autonomic fibers are blocked and the patient may be aware of touch and yet feel no pain when surgery starts.

Blood Supply

Arterial Supply:

The two posterior spinal arteries arise from the vertebrals and supply the posterior 1/3 of the cord.

The anterior spinal artery arises from the vertebrals and supplies the anterior 2/3 of the cord.

The radicular arteries enter every intervertebral foramen and supply the spinal nerve roots

The radiculospinal branches arise from the vertebral arteries and the aorta. Of these, the largest is the Artery of Adamkiewicz. It supplies much of blood flow to anterior spinal artery.

Venous drainage:

Anterior spinal vein

Posterior spinal vein

Approaches for Spinal Anesthesia

Median Approach. The most common approach, the needle or introducer is placed midline, perpendicular to spinous processes, aiming slightly cephalad.

Paramedian Approach. Indicated in patients who cannot adequately flex because of pain or whose ligaments are ossified, the spinal needle is placed 1.5 cm laterally and slightly caudad to the center of the selected interspace. The needle is aimed medially and slightly cephalad and passed lateral to the supraspinous ligament. If the lamina is contacted, the needle is redirected and "walked off" in a medial and cephalad direction.

Taylor or Lumbosacral Approach. This approach is useful in patients with calcified or fusion of higher intervertebral spaces. The injection site is 1cm medial and 1cm caudad of the posterior iliac spine. The needle is directed 45 degrees medial and 45 degrees caudad, after contacting the lamina the needle is walked upward and medially to enter the L5-S1 interspace.

Procedure

Anatomic landmarks for the desired level of the block are first identified.

Superior Iliac crests palpated and L4 is identified.

The spine is palpated to ensure spine position with relation to the plane of the floor.

A sterile field is established with povidone-iodine applied with three basic sponges, the solution is applied starting from the injection site moving outward in a circular fashion.

A fenestrated drape is applied, and using a sterile gauze, wipe the iodine from the injection site to avoid initiation into the subarachnoid space.A skin wheal is raised with 2cc of 1% lidocaine using a 25G needle to the selected space.

A 17G introducer is passed through the skin wheal, angled slightly cephalad through the epidermis, dermis, sub Q, supraspinous ligament, interspinous ligament, stopping in the ligamentum flavum.A 25G choice needle is inserted into the introducer, passing through the epidural space, dura, and arachnoid to the sub arachnoid space stopping when the presence of CSF is determinedCSF is aspirated and mixing lines are identified as a change in baricity and temperature as the local anesthetic and CSF mix in the syringe.The dose is slowly injected, aspirating after instillation.All needles are removed intact and the patient is positioned.

Monitoring

It is essential to monitor the respiration, pulse and blood pressure closely. The blood pressure can fall precipitously following induction of spinal anesthesia, particularly in the elderly and those who have not been adequately preloaded with fluid. Warning signs of falling blood pressure include pallor, sweating or complaining of nausea or feeling generally unwell.

For example, a moderate fall in systolic blood pressure to 80mmHg in a young fit patient or 100mmHg in an older patient is acceptable, provided the patient looks and feels well and is adequately oxygenated.

Bradycardia is quite common during spinal anesthesia particularly if the surgeon is manipulating the bowel or uterus. If the patient feels well, and the blood pressure is maintained, then it is not necessary to give atropine. If,

however, the heart rate drops below 50 beats per minute or there is hypotension, then atropine 300-600mcg should be given intravenously.It is generally considered good practice for all patients undergoing surgery under spinal anesthesia to be given supplemental oxygen by face mask at a rate of 2-4 liters/minute, especially if sedation has also been given.

Spinal Needles

Pencil Point Needles (Sprotte)

Designed to spread the dural fibers and help reduce the occurrence of post dural puncture headache

Yields a distinct "pop" as the pencil point penetrates the dura

Offers increased "tip strength" to minimize bending or breakage

Precision-formed side hole enables directional flow of anesthetic and reduces the possibility of straddling the dura

Tracks straight when advancing through ligaments toward the dura

Cutting Needle (Quincke)

Dural "pop" is less likely to be appreciated due to the sharper tip

Increased risk of Postdural Puncture Headache due to increased trauma to the dura

Introducer may not be necessary depending on patient size

Common Local Anesthetics

Factors Affecting the Spread of the Local Anesthetic Solution

A number of factors affect the spread of the injected local anesthetic solution within the CSF and the ultimate extent of the block obtained. Among these are:

the baricity of the local anesthetic solution

the position of the patient

the concentration and volume injected

the level of injection

the speed of injection

The specific gravity of the local anesthetic solution can be altered by the addition of dextrose. Concentrations of 7.5% dextrose make the local anesthetic hyperbaric (heavy) relative to CSF and also reduce the rate at which it diffuses and mixes with the CSF. Isobaric and hyperbaric solutions both produce reliable blocks. The most controllable blocks are probably produced by injecting hyperbaric solutions and then altering the patient's position.

Assessing the Block

Some patients are very poor at describing what they do or do not feel; therefore, objective signs are valuable. If, for example, the patient is unable to lift his legs from the bed, the block is at least up to the mid-lumbar region.Sensory loss can best be assessed by testing temperature sensation using an alcohol swab. First touching the patient with the damp swab on the chest or arm (where sensation is normal), so that they appreciate that the swab feels cold. Then work up from the legs and lower abdomen until the patient again appreciates that the swab feels cold. The level of sympathectomy can be best assessed with light pin pricks moving from nipple line down.

Common Complications

Postdural Puncture Headache incidence related to use of larger needles (22G), cutting needles. Occurrence can� also be reduced by rotating the needle so that the bevel is pointed to the side, this decreases trauma to the dura.

Transient Radicular Syndrome/Transient Neurological Syndrome self resolving pain related to the use of� Lidocaine, lithotomy position, and early ambulation post-op.

Backache

Hypotension

Itching

Less Common Complications

Cauda Equina Syndrome

Total Spinal Urinary Retention

Cardiac Arrest

Spinal/Epidural Hematoma

Aseptic Meningitis

Bacterial Meningitis

Cranial Nerve Palsies

Cranial Subdural Hematoma

Contraindications

Relative Contraindications

Absolute Contraindications

Hypovolemia

Patient refusal

Preexisting neurologic disorders

Infection at puncture site

Chronic back pain

Generalized sepsis

Localized infection peripheral to the regional technique site

Severe coagulation abnormalities

Patients taking ASA, NSAIDS, dipyridamole

Raised ICP

Medications

Midazolam is a short-acting benzodiazepine in adults with an elimination half-life of one to four hours; however, in the elderly, as well as young children and adolescents, the elimination half-life is longer. Itis metabolised by cytochrome P450 (CYP) enzymes and by glucuronide conjugation. The therapeutic as well as adverse effects of midazolam are due to its effects on the GABAA receptors; midazolam does not activate GABAA receptors directly but, as with other benzodiazepines, it enhances the effect of the neurotransmitter GABA on the GABAA receptors (↑ frequency of Cl− channel opening) resulting in neural inhibition. Almost all of the properties can be explained by the actions of benzodiazepines on GABAA receptors. This results in the following pharmacological properties being produced: sedation, hypnotic, anxiolytic, anterograde amnesia, muscle relaxation and anti-convulsant.

Nalbuphine is a semi-synthetic opioid agonist-antagonist analgesic of the phenanthrene series. It is chemically related to the widely used opioid antagonists, naloxone and naltrexone, and the potent opioid analgesic, oxymorphone. It is available in two concentrations, 10 mg and 20 mg of nalbuphine hydrochloride per mL. Both strengths contain 0.94% sodium citrate hydrous, 1.26% citric acid anhydrous, 0.1% sodium metabisulfite, and 0.2% of a 9:1 mixture of methylparaben and propylparaben as preservatives; pH is adjusted, if necessary, with hydrochloric acid. The 10 mg/mL strength contains 0.1% sodium chloride.

Atracurium is susceptible to degradation by Hofmann elimination and ester hydrolysis as components of the in vivo metabolic processes. The initial in vitro studies appeared to indicate a major role for ester hydrolysis but, with accumulation of clinical data over time, the preponderence of evidence indicated that Hofmann elimination at physiological pH is the major degradation pathway[ vindicating the premise for the design of atracurium to undergo an organ-independent metabolism.

Tramadol acts as a μ-opioid receptor agonist,[41][42] serotonin releasing agent, norepinephrine reuptake

inhibitor, NMDA receptor antagonist (IC50=16.5 μM), 5-HT2C receptorantagonist (EC50=26 nM), (α7)5 nicotinic

acetylcholine receptor antagonist, TRPV1 receptor agonist and M1 and M3 muscarinic acetylcholine

receptor antagonist.The analgesic action of tramadol is not fully understood, but it is believed to work through

modulation of serotonin and norepinephrine in addition to its relatively weak μ-opioid receptor agonism. The

contribution of non-opioid activity is demonstrated by the fact that the analgesic effect of tramadol is not fully

antagonised by the μ-opioid receptor antagonist naloxone.

Ketorolac :the primary mechanism of action responsible for ketorolac's anti-inflammatory, antipyretic and

analgesic effects is the inhibition of prostaglandin synthesis by competitive blocking of

the enzyme cyclooxygenase (COX). Ketorolac is a non selective COX inhibitor.