Preoperative Evaluation. Premedication to Adults and Children

Preoperative assessment

In the preoperative assessment, the patient’s health is evaluated and the type of anesthesia the patient should receive based on the current surgery. The patient is informed in the preoperative conversation about the perioperative course. It is prescribed which premedication the patient should receive and which of the regular medicines to be taken on the day of surgery. The preoperative assessment benefits both the patient and the anesthesiologist as well as determines the design of the anesthesia and the surgical procedure.

The preoperative assessment is usually done one or more days before surgery. Of course, in an emergency, this happens close to the imminent operation. The patient’s health is evaluated in the history of the patient as well as the available journal and other relevant data (lab samples, ECG, X-ray, etc.). The patient’s health is assessed first and foremost regarding cardiovascular function but also the overall health with identification of other possible risk factors for an upcoming anesthesia such as a difficult to access airway, severe obesity, severe patient, increased bleeding tendency, severe allergies, impaired general condition, etc.

The type of anesthesia to be performed regarding airway control, inducers, analgesics, muscle relaxants, anesthesia maintenance and postoperative pain relief should be planned and determined. The anesthetic form to be given is determined; TIVA, TCI, inhalation or combination anesthesia. Airway management is planned with oral intubation, nasal intubation, fiber intubation, video laryngoscopy, mask anesthesia, laryngeal mask or spontaneous breathing (mask, chanterelle or oxygen catheter). It is possible to decide type of regional anesthesia with blockades. It is planned and decided what type of anesthesiologic equipment and monitoring should be used, CVC, arterial line, epidural catheter, ultrasound, etc. Ev. planned for more advanced equipment with cardiac output volume measurement or analysis of the arterial pressure curve, such as Swan-Ganz, LiDCO, Cardio-Q, thermodilution, PiCCO, NiCO, Vigileo, etc. for major surgery or hemodynamically unstable patient.

You plan the arrangement on the operating table and assess the expected size of the bleeding. It is planned to deliver intravenous fluid and order blood products. In the preoperative assessment, ASA grade (I-IV) and intubation assessment should be determined with Malampati grade I-IV, SM distance (sternomental distance), TM distance (thyroid momentum). Prior known intubation problems and other previously known anesthesia complications should be noted. The need for sedation, PONV prophylaxis and postoperative pain relief should be determined.

Design of the Anesthesia Procedure
Induction AgentBasic AnalgesiaMuscle
relaxants
Anesthesia maintenancePostoperative Analgesia   
PropofolFentanylSuccinylcholine (Succamethonium)SevofluraneMorphine
ThiopentoneAlfentanilRocuroniumDesfluraneKetobemidone
KetaminRemifentanilAtracuriumIsofluraneParacetamol
SevoraneSufentanilCisatracuriumKetamineEpidural
Propofol
Remifentanil
Alfentanil

Anesthetic form is determined:

  • Induction agent: Propofol, ketamine, thiopentone, Sevorane
  • Analgesics: Fentanyl, alfentanil, remifentanil, sufentanil
  • Muscle relaxants: rocuronium, succametonium, vecuronium, none
  • Anesthesia maintenance: Sevoflurane, Isoflurane, Desflurane, Ketalamine, Propofol, remifentanil, alfentanil.
  • Postoperative pain relief

Any allergies are noted, especially for antibiotics, ASA, NSAIDs or local anesthetics. There are special nursing problems. Problems with the layout should be noted, side position, kidney position, abdominal position, bean position, high leg supports etc. Current lab tests are reviewed and the current ECG is evaluated.

After the preoperative assessment, premedication and anesthesia form are determined as well as any additional examinations or investigations needed before the impending surgery. Examples of supplementary examinations may be heart and lung radiographs, cardiac ultrasound (UCG), work tests or spirometry. The scope of the supplementary examination should be as small as possible but still ensure that the patient will be in optimal condition before surgery.

In the preoperative interview, the patient should be given information about the upcoming surgery and anesthesia. The patient usually wants to know when, where and how he or she should be operated. Unfortunately, information is often missing from the preoperative assessment. The patient should be informed in such a way that he or she can feel calm and confident before the upcoming surgery. The same goes for children and their parents. This presupposes that the anesthesiologist is well acquainted with the patient’s health and can evaluate various risk factors as well as the nature of the future procedure and the routines and practices that exist in the operating department.

ASA PHYSICAL STATUS CLASSIFICATION SYSTEM
ASA PS Classification DefinitionExamples, including, but not limited to:
ASA IA normal healthy patientHealthy, non-smoking, no or minimal alcohol use
ASA II A patient with mild systemic diseaseMild diseases only without substantive functional limitations. Examples include (but not limited to): current smoker, social alcohol drinker, pregnancy, obesity (30 < BMI < 40), well-controlled DM/HTN, mild lung disease
ASA IIIA patient with severe systemic diseaseSubstantive functional limitations; One or more moderate to severe diseases. Examples include (but not limited to): poorly controlled DM or HTN, COPD, morbid obesity (BMI ≥40), active hepatitis, alcohol dependence or abuse, implanted pacemaker, moderate reduction of ejection fraction, ESRD undergoing regularly scheduled dialysis, premature infant PCA < 60 weeks, history (>3 months) of MI, CVA, TIA, or CAD/stents.
ASA IV A patient with severe systemic disease that is a constant threat to lifeExamples include (but not limited to): recent ( < 3 months) MI, CVA, TIA, or CAD/stents, ongoing cardiac ischemia or severe valve dysfunction, severe reduction of ejection fraction, sepsis, DIC, ARD or ESRD not undergoing regularly scheduled dialysis
ASA V A moribund patient who is not expected to survive without the operationExamples include (but not limited to): ruptured abdominal/thoracic aneurysm, massive trauma, intracranial bleed with mass effect, ischemic bowel in the face of significant cardiac pathology or multiple organ/system dysfunction
ASA VI A declared brain-dead patient whose organs are being removed for donor purposes


Premedication to Adults

The premedication usually includes an anaesthesiologic preoperative assessment of a patient prior to a surgical operation as well as prescribing of drugs and possibly. supplementary medical examination prior to surgery. Usually the premedication is given about an hour before the anesthesia start in the care ward, but can also be given if needed in the operating ward, usually as an oral or intravenous treatment. Premedication is usually given per os but if the patient has difficulty swallowing it can also be given intramuscularly or intravenously. The premedication follows regular routines in the care ward/operating department and is usually given according to a predetermined schedule with regard to age and weight. There are a variety of drugs used in premedication, but the main principle is that these should be analgesic and relaxing. In addition, some of the patient’s fixed medications are given, usually as few as possible. The advantage of premedication is that the anesthesia induction will be calmer and the amount of anesthetic agent can be reduced. The disadvantage is that the patient can become very tired after the operation.

There are a variety of drugs used in premedication. The main principle is that these should be analgesic and relaxing. Common combinations often contain paracetamol in combination with a benzodiazepine or benzodiazepine-like drug, sometimes with the addition of an NSAID. Also, opioids can advantageously be used in premedication. Several different combinations exist.

Combinations of Premedication to Adult Patients for General Surgery. Oral administration if other route is not indicated
Analgetics/ParacetamolOpioidSedative/HypnoticNSAIDCorticosteroids
Paracetamol (acetaminophene) 1-2 gOxycontin 5-10 mgBetametason 8 mg
Paracetamol 1-2 g (500 mg x 2 x III)Zolpidem 5 mgEtoricoxib 120 mg or similar like diclofenac 50-100 mgBetametason 8 mg
Paracetamol 1-2 gDiazepam 2,5-5 mgBetametason 8 mg
Paracetamol 1-2 gOxazepam 10-15 mg
Paracetamol 1-2 gFlunitrazepam 0,5-1 mg
Paracetamol 1-2 gOxycontin 10-15 mgZolpidem 5 mg
Paracetamol 1330 mg (x 3)Oral syrup Midazolam 5-15 mgEtoricoxib 120 mg or similar like Diclofenac 50-100 mgBetametason 8 mg
Patients not suitable for selective COX-2 inhibitors can be given: Tramadol 50 mg

If sedatives are needed in the operating department: midazolam orally (midazolam for i.v. use, 5 mg/ml) or midazolam 1-2 mg i.v. on the pre-op. or Propofol 10-30 mg i.v. on the pre-op center or operating theatre.

Dosage of Midazolam Orally to Adults

AgeDose in mg
< 50 years 15 mg
50–60 years 10 mg
60–70 years 7,5 mg
> 70 years 5 mg
Blended in apple juice/juiceGiven orally 1 hour before operation

Premedication to Children

There are a variety of drugs used in premedication for children to get analgesia and anxiolysis. The main principle is that these drugs should be analgesic and relaxing. The general preoperative care of children with parents is essential to gain trust from the patient and parents with a good and safe introduction of anesthesia. Frightened and anxious parents can easily spread their concerns to the child, preoperative information is a and o. During anesthesia induction, it is appropriate if only the calmest parent is present.

Clonidine

Dosage: 2-5 µg/kg orally, provides good sedation in premedication. The disadvantage is that the agent has a long impact time and must be given well in advance, 60-90 minutes in advance. Premedication with oral solution clonidine hydrochloride 20 µg/ml or Tabl Clonidine 75 µg.

Dosage

Dosage range: 2-4- (6) µg/kg.

Dose: We recommend 3 µg/kg. Children <3 years and all ENT children 2-3 μg/kg. As an example; child weight 15 kg x 3 μg/kg = 45 μg and 2.2 ml (20 μg/ml) of clonidine hydrochloride.

Dexmedetomidine and Clonidine for Children. Sedation "Sedanalgesia"
Dexmedetomidine 100 µg/mlClonidine 150 µg/ml (Catapres)
IntravenouslyIntranasallyIntravenouslyOrallyEpidurally (EDA)
1 µg/kg (max 200 µg) in an infusion or by a slow injection 1,5-2 µg/kg
(MR 4 µg/kg) Max 200 µg
1-4 µg/kg x 31-4 µg/kg x 30,1-0,3 µg/kg/tim

Dexmedetomidine

Provides good premedication for young children who come for ear and throat surgery. Dexmedetomidine 100 mg/ml solution for injection can be given both nasally and buccally. Nasal administration is preferred as it provides better absorption and faster effect. The solution has no taste and does not burn in the nose. Dexmedetomidine is a specific alpha2 receptor agonist and its effect is similar to clonidine, but with more pronounced effect. The main effects are sedation and some analgesia. Dexmedetomidine has a shorter half-life, about 2 hours compared to clonidine 5-10 hours. The duration of administration is significantly longer compared to orally administered midazolam, approximately 20-40 minutes.

Dosage

Children 1-3 years are given 1 µg/kg. Children 3-10 years are given 1-2 µg/kg. Children over 10 years are given 1-3 µg/kg. The dose can be increased with increasing age to a maximum of 3 µg/kg. The easiest way is to use nasal administration with MAD (Mucosal Atomization Device) or MADdy (pediatric variant) coupled to syringe. The prescribed dose of drug is diluted to the desired volume (usually 0.3-0.5 ml) with physiological saline.

Monitoring

Patients must have the presence of parents or staff during the waiting period after application. Peroperative monitoring with blood pressure and ECG. The child may need some extended awakening time compared to patients without premedication.

Acetaminophen

Alone or in combination. Common combinations of pharmacological premedication in children usually contain paracetamol (30 mg/kg x 1) in combination with benzodiazepines or benzodiazepine-like drugs, sometimes with the addition of an NSAID preparation. Paracetamol is given either as a tablet, oral solution or suppository (Table 6). Children under 6 months are not usually premedicated. Several different drug combinations are common. Various variants of sedative sympathetic stimulant drugs have become more common in recent times, such as clonidine and dexmedetomidine. These are usually given as oral solution but can also be given intravenously.

Routinely, the loading dose of paracetamol (max oral 30 mg/kg) is given in the premedication. Conveniently, the oral solution of paracetamol is 24 mg/ml, 1 ml/kg in the care department before most operations. For more painful interventions, children> 6 months are also given NSAIDs. The youngest children, < 6 months, are usually not premedicated.

Premedication and Maintenance Therapy with Paracetamol for Children 6-25 kg
 Premedication Maintenance first 2 days
dosage 20 mg/kg body weight
Child weight (kg)Oral solution Paracetamol 24 mg/mlSupp Paracetamol (mg)Tablet Paracetamol (mg)Oral solution Paracetamol 24 mg/mlTablet Paracetamol (mg)Supp Paracetamol (mg)
6 - 8 kg8,5 ml250 mg-2,5 ml x 4-60 mg x 4
8 - 10 kg12 ml310 mg-3,5 ml x 4-125 mg x 3
10 - 12 kg14 ml375 mg-5 ml x 3-125 mg x 4
12 - 15 kg17,5 ml500 mg-5 ml x 4-185 mg x 4
15 - 20 kg22 ml625 mg-7,5 ml x 4-250 mg x 3
20 - 25 kg28 ml750 mg500 mg10 ml x 4500 mg x 3250 mg x 4
Intravenous Paracetamol Dosage for Children
Paracetamol intravenously10 mg/ml
Weight (kg)Dosage
<1 mån7,5 mg/kg
>1 mån15 mg/kg
4 - 10 kg6 - 15 ml x 4
10 - 20 kg15 - 30 ml x 4
20 - 33 kg30 - 50 ml x 4
33 - 50 kg50 - 75 ml x 4
50 - 66 kg75 - 100 ml x 4
>66 kg100 ml x 4
Paracetamol Dosage for Children Orally or Rectally
Loading doseMaintenance dose
Weight (kg)Oral solution 24 mg/mlSupp.Weight (kg)Oral solution 24 mg/mlSupp.
32,5 mlS. 60 mg32,5 ml x 3S. 60 mg x 3
43,5 mlS. 60 mg43,5 ml x 3S. 60 mg x 4
55 mlS. 125 mg54 ml x 4S. 125 mg x 3
6 - 87 mlS. 250 mg6 - 85 ml x 4S. 125 mg x 4
9 - 1212 mlS. 310 mg9 - 127,5 ml x 4S. 185 mg x 4
13 - 1516 ml13 - 1511 ml x 4
Weight (kg)Oral solutionTabletWeight (kg)Oral solutionTablet
16 - 1920 mlT. 500 mg16 - 1913 ml x 4T. 250 mg x 4
20 - 2425 mlT. 500 mg20 - 2417 ml x 4T. 500 mg x 3
25 - 3030 mlT. 750 mg25 - 3021 ml x 4T. 500 mg x 4
31 - 3440 mlT. 1000 mg31 - 3425 ml x 4T. 750 mg x 3
35 - 4240 mlT. 1000 mg35 - 4230 ml x 4T. 750 mg x 4
43 - 5050 mlT. 1250 mg43 - 5035 ml x 4T. 1000 mg x 3
50 - 7060 mlT. 1500 mg50 - 7040 ml x 4T. 1000 mg x 4
>70 kg80 mlT. 2000 mg>70 kg40 ml x 4T. 1000 mg x 4

Benzodiazepines

Alone or in combination. A common standard mixture for children is midazolam + atropine in the oral solution. This mixture is dosed according to schedule by weight. Midazolam often provides trouble-free needle removal if EMLA has been used. Rectally, 0.3 mg/kg (max. 10 mg) is given as nasal spray 0.2 mg/kg (max. 5 mg) and 0.5 mg/kg (max. 15 mg) orally.

Some children, e.g. Those who are very worried or who have previously experienced major problems with anesthesia may be offered a heavier premedication. Flunitrazepam in tablet form 0.05 mg / kg, gives after about 20 minutes heavy sedation lasting at least 1 hour. This premedication can be given in the care department and the time must be coordinated with the surgery department. In some cases, midazolam may be given by anesthesia professionals to facilitate a troublesome induction. The child must not be alone after the administration of flunitrazepam or midazolam. An alternative to midazolam is triazolam. Dosage triazolam 0.125 mg, ½ tablet for children weighing 20-30 kg and 0.125 mg, 1 tablet for children weighing 30-40 kg. Older children may find that waiting for the care department before surgery is long and worrying. Diazepam, tablet or suppository, 0.5 mg/kg rounded down, max. 25 mg rectally, can provide relief.

Atropine is given after medical prescription on surgery, either intravenously, p o, s c, rectally or sublingually.

Premedication with midazolam (children 10-25 kg)

A common standard mixture for children is midazolam + atropine in oral solution given per os. In addition, paracetamol is usually given 30 mg/kg x 1.

Pharmacodynamic properties Midazolam 1 mg/ml + Atropine 0.05 mg/ml. Dosage: 0.4 mg (= 0.4 ml)/kg according to the list below. The maximum dose for the mixture is 10 ml (orange flavor).

Premixed Oral Solution of Midazolam 1 mg /ml with Atropine 0.05 mg/ml for Children 10-25 kg.
Weight (kg)Dose in ml Midazolam/Atropine
104,0
114,5
125,0
135,0
145,5
156,0
166,5
177,0
187,0
197,5
208,0
218,0
228,5
239,0
249,5
2510,0

Premedication with midazolam (children 10-25 kg).

Midazolam + atropine in a mixture that is mixed clearly in the operating ward. Midazolam 1 mg/ml is mixed with atropine 0.5 mg/ml and add strong juice to a solution of 5-12 ml. Dosage: midazolam 0.4 mg/kg + atropine 0.02 mg/kg orally listed below. In addition, paracetamol is usually given 30 mg/kg x 1.

Premedication with a blend of Midazolam 1 mg/ml + Atropine 0.05 mg/ml mixed by the Anaesthesia Staff
Weight (kg)Volume in ml of the solutionDose of respective drugs in the solution
Midazolam/Atropine (mg)
104,44,0/0,20
114,94,5/0,225
125,55,0/0,25
135,55,0/0,25
145,555,5/0,275
156,66,0/0,30
167,156,5/0,325
177,77,0/0,35
187,77,0/0,35
198,257,5/0,375
208,88,0/0,40
218,88,0/0,40
229,358,5/0,425
239,99,0/0,45
2410,459,5/0,475
251110,0/0,50

Premedication for rectal administration of midazolam (children 5-20 kg).

Midazolam + atropine in oral solution, which is mixed clearly in the surgery department for rectal administration. Midazolam 5 mg/ml is mixed with 2 ml of NaCl to the strength of 3 mg/ml. Dosage 0.3 mg/kg = 0.1 ml/kg. + Atropine 0.5 mg/ml is mixed undiluted in the midazole mixture.

Dose of premedication for Rectal Administration of Midazolam/Atropine to Children 5-20 kg
Weight (kg)Midazolam 3 mg/ml
Dose (mg)
Midazolam 3 mg/ml
Volume (ml)
Atropine 0,5 mg/ml
Dose (mg)
Atropine 0,5 mg/ml
Volume (ml)
51,50,50,150,3
7,52,250,750,150,3
10310,150,3
12,53,751,250,250,5
154,51,50,250,5
206,020,250,5
Midazolam Dosage for Sedation of Children
IntravenouslyRectallyNasallyOrally/PEG
0,1 mg/kg (max 5 mg)0,2-0,3 mg/kg (max 7,5-10 mg)0,2 mg/kg (max 5 mg)0,3-0,5 mg/kg (max 10-15 mg)
An additional dose can be given according to the schedule below
0,05 mg/kg (after 5 minuter)0,05 mg/kg (after 20 minuter)0,05 mg/kg (after 10 min)0,05 mg/kg (after 20 min)
At least one hour of monitoring after the last doseAt least one and a half hour of monitoring after the last doseAt least one hour of monitoring after the last dose
Flumazenil for reversal of Bensodiazepines
Flumazenil 0,1 mg/ml ivAntidote for bensodiazepine overdose
5 µg/kg (0,05 ml/kg) intravenously once per minute up to 40 µg/kg (maximum dose 2 mg)If lack of effect: continous infusion 2-10 µg/kg/hour

Ketamine

Another alternative, ff.a. For heart disease children aged 1-4 years, ketamine is 7 mg/kg mixed with midazolam 0.3 mg/kg. In cases where the child is not involved at all, ketamine can be given intramuscularly. 3-5 mg/kg, in some cases up to 10 mg/kg, preferably in melteltoideus. If one does not want to give an injection and the child does not cooperate, exceptionally ketamine per os can be given. This induction method is time-consuming, about 20 minutes, until needle can be set. 6 mg/kg are mixed in a little liquid, e.g. Coca Cola.

Ketamine for Sedation of Children
Ketamine 10 mg/ml50 mg/ml
Iv bolus:0,5 mg/kgIv infusion 0,02-0,12 mg/kg/hour
Rectally4-5 mg/kg
Esketamin (S-ketamine )5 mg/ml25 mg/ml
Rectally3 mg/kg
Nasally1,5 mg/kg
Must be combined with Midazolam or Dexmedetomidine!

Pentothal (Thiopentone)

Rectal induction with thiopental (Pentocur – “Pentorect/Sleeping Beauty”) can be given to young children 1-4 years (10-20 kg) if you do not want to insert a needle when the child is awake. This is an older form of anesthesia that is hardly used at all anymore. Pentotal can be given rectally in the dose of 30 mg/kg from a solution of 100 mg/ml. This premedication acts as anesthetic induction and is given in the operating ward. Weight limits are not sharp, this induction often works well for sensitive children weighing 5-30 kg. The maximum dose rectally is 600 mg Pentotal. Pentorect can be used as the only anesthetic form for minor surgical procedures or when you only want the child to lie still, such as for example. during X-ray examinations and certain radiological interventions.

NSAID-approved preparations

NSAID that can be used for younger children are the ibuprofen and diclofenac suppositories.

Premedication with Oral Ibuprofen 20 mg/ml for Children 6-10 kg (> 6 months)
Weight (kg)Dose (ml)
7 kg2,5 ml x 3
8 kg3,0 ml x 3
9 kg3,5 ml x 3
10 kg4,0 ml x 3
Premedication with Suppositories Diclofenac (Voltaren) 25 mg (>1 year and >10 kg)
Weight (kg)Dosage of suppositories (number)
10 kg½ supp x 2
12,5 kg½ supp x 2
15 kg½ supp x 3
20 kg1 supp x 2
25 kg1 supp x 3
30-40 kg1½ supp x 3
Ibuprofen for treatment of postoperative pain in children
IbuprofenOral suspension 20 mg/ml
≥ 6 months 7,5 mg/kg x 4 alt. 10 mg/kg x 3Max 1200 mg/day
0,375 ml/kg x 4 alt. 0,5 ml/kg x 3.Max 60 ml/day
Oral or rectal administration of diclofenac to children
Only to children ≥ 6 months 
>50 kg50+50+50 mg50+50+50 mg
Weight (kg)Supp.Tablet
8-14 kg25 mg25 mg
15-1925+0+25 mg25+0+25 mg
20-2425+0+25 mg25+0+25 mg
25-2750+0+25 mg25+0+25 mg
30-3450+0+25 mg50+0+25 mg
35-4050+0+50 mg50+0+50 mg
40-5050+0+50 mg50+0+50 mg

Clonidine

Clonidine

Dosering: 2-5 μg/kg per os, ger god sedation i premedicineringen. Nackdelen är att medlet har lång anslagstid och måste ges i god tid, 60-90 minuter i förväg. Premedicinering med Mixtur Klonidinhydroklorid 20 μg/ml eller Tabl Klonidin 75 μg.

Dosering

Doseringsintervall: 2-4-(6) μg/kg. Dos: Vi rekommenderar 3 μg/kg. Barn < 3 år och alla ÖNH-barn 2-3 μg/kg. Ex; barnets vikt 15 kg x 3 μg/kg = 45 μg och 2,2 ml (20 μg/ml) klonidinhydroklorid.

Dexmedetomidine and Clonidine for Children. Sedation "Sedanalgesia"
Dexmedetomidine 100 µg/mlClonidine 150 µg/ml (Catapres)
IntravenouslyIntranasallyIntravenouslyOrallyEpidurally (EDA)
1 µg/kg (max 200 µg) in an infusion or by a slow injection 1,5-2 µg/kg
(MR 4 µg/kg) Max 200 µg
1-4 µg/kg x 31-4 µg/kg x 30,1-0,3 µg/kg/tim