By Professor of Anaesthesia and Surgical Intensive Care Faculty of - PowerPoint PPT Presentation

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Professor of Anaesthesia and Surgical Intensive Care Faculty of Medicine Alexandria University Lecturer in Anaethesia and Surgical Intensive Care Faculty of Medicine Alexandria University

• Pain is an unpleasant sensory and emotional experience associated with actual or potential tissue damage; Pain in the knee joint is the most common complication after tibial nailing. Its occurrence has been reported from 10 to 86% of the cases, particularly in young and active patients. • It is therefore important to choose an effective analgesic regimen with minimal side ‐ effects to allow timely mobility, optimal functional recovery and to decrease postoperative morbidity and mortality.

• Spinal anesthesia is a well-established technique for lower limb surgeries. It is easy to perform and provides fast onset and effective sensory and motor block. • The combination of local anaesthetics and opioids for postoperative pain relief allows reduction in doses of both classes of drugs, as a consequence lessening the likelihood of side effects attributable to each.

• Opioids combine to specific opioid receptors in the nervous system and other tissues. There are three principal types of opioid receptors, μ, κ, and δ . In addition, there are also three subtypes of μ -receptor: μ 1 and μ 2, and μ 3. • The pharmacodynamic reaction to an opioid depends on the receptor to which it binds, its affinity for this receptor, and rather the opioid is an agonist or an antagonist.

• Opioids injected in the subarachnoid space seem to act mainly on µ receptors in the substantia gelatinosa of the dorsal horn by inhibiting excitatory neuropeptide release from C fibers. The extent of uptake from the cerebrospinal fluid by the dorsal horn is determined mainly by the physicochemical properties of the drug, and in specific, lipid solubility. Lipid-soluble compounds enjoy larger direct diffusion into neural tissue besides greater delivery to the dorsal horn by spinal segmental arteries.

• Nalbuphine is a highly lipid soluble opioid with activity that suggests an agonist action at the κ opioid receptor and activity as an antagonist at the µ- opioid receptor. • The most frequent side effect in patients treated in clinical studies with Nalbuphine was sedation (36%), (nausea, vomiting 6%), (dizziness, vertigo 5%), (dry oral mucosa 4%), and (headache 3%). Anaphylactic/anaphylactoid and other serious allergic reactions.

• Fentanyl is a lipophilic μ -receptor agonist exerts its effect by combining with opioid receptors in the dorsal horn of spinal cord. • Naloxone, is a pure opioid antagonist. Naloxone is a medication used to counter the actions of opioid especially in overdose. It will mainly reverse the depression of the CNS, respiratory system, and hypotension.

• the aim of this work was to compare the effect of intrathecal nalbuphine versus intrathecal fentanyl as adjuvants to bupivacaine, as regards : • 1ry outcome: the post-operative analgesia. • 2ry outcomes: the hemodynamic stability, the onset and duration of sensory/motor block and side effects.

• After approval from the local ethical committee and written informed consent was obtained. • This study was carried out in Elhadra University Hospital on fifty patients aged 20 – 50 years; belonging to American Society of Anaesthesiologists (ASA) physical status I or II, scheduled for internal fixation of tibia of expected duration less than 3 h, under spinal anaesthesia.

• Patients with significant co-existing conditions such as hepatorenal and cardiovascular diseases. • Patients with contraindications to regional anesthesia like local infection or bleeding disorders. • Patients with allergy to opioids, long-term opioids use, and a history of chronic pain. • Patients with extremes in weight or in length.

• Patients received intrathecal injection of 2 ml of 0.5% hyperbaric bupivacaine plus 1 ml fentanyl (50 μg) . • Patients received intrathecal injection of 2 ml of 0.5% hyperbaric bupivacaine plus 1ml nalbuphine hydrochloride (1.6 mg).

• Medical history and Clinical examination • Routine laboratory investigations

• Patients were monitored using standard monitoring (pulse oximetry, electrocardiogram, noninvasive arterial blood pressure monitoring) using a multi channel monitor. • Before the administration of neuroaxial anaesthesia, 18-gauge intravenous cannula was inserted and intravenous preload of 10 mL/kg lactated Ringer’s solution was given.

• Patient was placed in the sitting position; At the puncture site, 2 ml of 2% lidocaine were injected subcutaneously. The puncture was performed at L3- 4 interspace using a 25 gauge spinal needle (Quincke) by midline approach. • After a successful dural puncture, the anaesthetic solution was injected according to the group. The patient was then turned supine immediately elevation of the head by a pillow. Oxygen administered through a simple face mask (5 L/ min).

• Patients received intrathecal injection of 2 ml of 0.5% hyperbaric bupivacaine plus 1 ml fentanyl (50 μg) . • Patients received intrathecal injection of 2 ml of 0.5% hyperbaric bupivacaine plus 1ml nalbuphine hydrochloride (1.6 mg); (20 mg Nalbuphine in 12 ml normal saline 0.9%).

The following parameters were measured for each patient: • Age (yrs), sex, weight (kg) and Height (cm). • Non-invasive mean arterial blood pressure (mmHg). • Heart rate (beats/minute).

These parameters were measured and recorded: • At 5 minutes before the intrathecal injection. • At 2, 4, 6, 8, 10, minutes after intrathecal injection and then every 15 minutes till the end of the procedure.

Sensory blockade: was determined by ice cold test to estimate the following: • Time (in minutes) of the onset of sensory block at T10 dermatome. • Time (in minutes) for 2 segment regression which was defined as the time it took for the sensory level to decrease by 2 dermatomal levels measured from the highest obtained sensory level every 15 min.

Motor blockade: was evaluated by the (modified Bromage score): • Time (in minutes) of onset of motor blockade from the end of intrathecal injection till the patient reached complete motor blockade (modified Bromage score 3). • Duration of motor block (in minutes) was recorded from the time at which the patient reached complete motor blockade (modified Bromage score 3) to the time the patient was able to rise his/her legs in bed against gravity (modified Bromage score 0) every 30 min in the post-operative care unit.

Able to raise straightened legs against resistance, no detectable motor block. Unable to raise straightened legs, but able to flex knees. Unable to flex knees, but able to flex ankle. Unable to move hip, knee or ankle.

• Patients was assessed using Visual analogue scale (VAS), It ranges from 0 indicating no pain till 10 indicating severe intolerable pain with variable degrees of ascending pain in between. •

• The duration of analgesia was defined as the period from spinal injection to the first time when the patient complained of pain in the postoperative period (VAS ≥ 1). • VAS assessed in the immediate postoperative period, then every 2hours for the first 8hours, then every 6hours for the rest of the first 24hours.

• The time of the first request analgesia was recorded (VAS ≥ 4) and treated by intramuscular diclofenac sodium (75mg) • Total dose of analgesic requirements was calculated and elaborated statistically.

• Such as, hypotension, bradycardia, respiratory depression, pruritus, nausea, vomiting and shivering were recorded.

70 F N 60 50 Percentage 40 30 20 10 0 Male Female

Mean of age (years) 10 15 20 25 30 35 0 5 F N

180 160 140 Mean of height 120 100 80 60 40 20 0 F N

80 70 Mean of weight 60 50 40 30 20 10 0 F N

Mean of duration of operation (min) 10 20 30 40 50 60 0 F N

Heart rate (beats/min) 100 0.0 75 80 85 90 95 5 min before N F After 2 min After 4 min After 6 min After 8 min After 10 min After 25 min After 40 min After 55 min

Mean arterial blood pressure (mmHg) 65 70 75 80 85 90 0 5 min before N F After 2 min After 4 min After 6 min After 8 min After 10 min After 25 min After 40 min After 55 min

Mean of time of the onset of sensory block (minutes) 0.2 0.4 0.6 0.8 1.2 1.4 1.6 1.8 0 1 F N

Mean of time for two-segment regression (minutes) 100 120 140 20 40 60 80 0 F N

Mean of onset of the motor blockade (minutes) 0 1 2 3 4 5 6 F N

Mean of duration of the motor blockade (minutes) 100 10 20 30 40 50 60 70 80 90 0 F N

Mean of duration of analgesia (minutes) 100 10 20 30 40 50 60 70 80 90 0 F N

Mean of time for 1 st rescue analgesia (minutes) 100 120 140 160 180 200 20 40 60 80 0 F N

Mean of time for 1 st rescue analgesia (minutes) 100 10 20 30 40 50 60 70 80 90 0 F N

F N 30 25 Percentage 20 15 10 5 0 Hypotension Nausea and Pruritis Shivering Bradycardia Respiratory vomiting depression Complications