Past medical history:
Atrial fibrillation, COPD, CHF
Medications:
Coumadin 3 mg PO daily, Albuterol MDI 2 puffs prn for shortness of breath, Spiriva 2 puffs daily, furosemide 20 mg PO daily, metoprolol ER 100 mg PO daily
Allergies:
NKDA
Physical exam:
Vitals:
BP 110/60, HR 65, RR 16, oxygen saturation 98% on nasal cannula at 3 L/min
Weight 160 lbs., Height 67 in.
Alert and oriented ×3, no focal neurological deficit
Irregular HR, no murmur; lungs—clear to auscultation
Visible deformity of the right elbow
Otherwise: non-contributory
- 1.
What are some relevant preoperative concerns and recommended work up?
This patient has a complicated medical history and has suffered trauma from a fall. Besides the general concerns, the preoperative evaluation for this patient should specifically include:
- 1.1
Clarifying the cause of the fall: a mechanical fall or a fall associated with other medical problems such as neurological (TIA, stroke) or cardiovascular (syncope, orthostatic hypotension, arrhythmia) deficits and/or events.
- 1.2
Assessing for concomitant injuries, especially cervical spine fractures and head injuries. If such injuries cannot be excluded by history and physical examination, a CT or MRI scan of the head and neck are recommended and the patient’s neck should be temporarily immobilized and supported in a collar.
- 1.3
Details of patient’s comorbidities:
Heart disease—obtain a 12-lead ECG; focus on active cardiac conditions, baseline functional class and cardiac work up, including review of recent echocardiography results if available. If active symptoms or suspicion of cardiovascular fall etiology, recommend a preoperative echocardiography exam to assess current function and rule out signs of ischemia.
COPD—assess stage of disease by history, severity and frequency of exacerbations, medication use, (including steroids), and home oxygen therapy.
Laboratory tests should include CBC, coagulation status, electrolytes, BUN, and creatinine.
- 1.1
- 2.
What are the anesthesia choices for this patient? What are the risks and benefits for each choice?
ORIF of the elbow can be conducted under general anesthesia, regional anesthesia, or a combination of both. However, each choice has considerations as follows:
- (a)
Brachial plexus block (BPB)
Benefits/advantages include:
Minimal hemodynamic changes
Superior pain control
Safer positioning (awake)
No cognitive effects
No need to manipulate the airway
Faster recovery
Risks/disadvantages include:
Diaphragmatic weakness—BPB, especially interscalene block, is strongly associated with ipsilateral hemidiaphragmatic block (weakness), which may be poorly tolerated by patients suffering from COPD or other chronic lung disease
Limited ability for postoperative assessment of neurologic function—this patient has a complex fracture, which is associated with a higher risk for acute compartment syndrome (ACS). There is still controversy about the role of nerve blocks in potentially complicating/“masking” the clinical picture of ACS delaying diagnosis of ACS (discussed below)
Lack of airway/ventilation control in (heavily) sedated patients
Difficult to guarantee a completely immobilized extremity
- (b)
General anesthesia
Benefits/advantages include:
High success rate (100%)
Initiated faster
Reliable
No need for specialized regional anesthesia skills or equipment
Risks/disadvantages include:
Significant hemodynamic changes, especially in sitting position
General anesthesia is associated with higher cardiovascular and pulmonary complication risks
Risks of airway manipulation
The choice of anesthesia should be based on a discussion of risks and benefits of each option and possible complications between anesthesiologist, patient and surgeon, in the immediate context of the patient’s medical conditions, their severity, and the procedure urgency. Surgeon’s preference and availability of regional anesthesia-trained personnel and equipment, all contribute to the choice of anesthesia
- (a)
- 3.
What are the contraindications for a brachial plexus block?
Absolute contraindications: Patient’s refusal
Relative contraindications include:
Allergy to local anesthetics
Preexisting nerve deficit or need to test/monitor nerve function after the surgery
Infection at the block site
Coagulopathy for deep (noncompressible space) nerve block
Patients at high risk for acute compartment syndrome
Patient with severe restrictive or obstructive pulmonary disease (except axillary block)
Severe time constraints—emergency surgery (if immediate anesthesia induction is indicated, block can still be performed postoperatively or intraoperatively)
- 4.
What are the regional anesthesia limitations and recommendations in anticoagulated patients?
According to the 2010 ASRA practice advisory on regional anesthesia in patients receiving antithrombotic or thrombolytic therapy [1], the same strict guidelines recommended for neuraxial blocks, should be also applied for deep noncompressible space blocks. For example, the procedure should be performed at least 12 h after a prophylactic dose of low-molecular weight heparin, and INR should be normal.
Even though there is no conclusive definition, deep noncompressible space blocks include paravertebral blocks, lumbar plexus block, and possibly the parasacral and transgluteal sciatic nerve blocks and infraclavicular blocks. For other brachial plexus block techniques, the threshold can be more liberal due to the ability to control the bleeding/hematoma by compression and especially with the added ability of ultrasound imaging to detect and more predictably avoid vascular structures. No specific consensus recommendations are available, regarding the coagulation status for superficial blocks, and the clinical decision rests upon the anesthesiologist’s clinical experience, judgment and meaningful discussion of risks, and benefits with the patient and the multidisciplinary team.
- 5.
Explain the anatomy relevant to brachial plexus blocks and discuss common approaches. How to choose a specific approach for a specific patient and procedure? What is the potential risk of each approach?
The brachial plexus is formed by the ventral primary rami of the C5-T1 spinal nerves (also called nerve roots) [2]. Five nerve roots unite, divide, and form trunks, divisions and cords as they travel through the neck and form terminal branches (Fig. 47.1).
Fig. 47.1
Anatomy of brachial plexus and cutaneous nerve supply [2]. With permission of Wolters Kluwer
The plexus provides motor and sensory innervation to the upper extremity, except for part of the cutaneous sensory innervation to the inner surface of the upper arm (intercostobrachial nerve—T2-3 intercostal nerves) and sensory cutaneous innervation to the top of the shoulder and the medial clavicle (cervical plexus C2-4).
The brachial plexus blocks are classified by the approach (anatomysite) of needle access to the plexus (Table 47.1).
Table 47.1
Common brachial plexus blocks—surgical area and specific complications
Common brachial plexus blocks | Area of injury/surgery | Specific complications |
|---|---|---|
Interscalene (roots and trunks) | Shoulder, upper arm | Diaphragmatic paralysis (phrenic nerve), recurrent laryngeal nerve block, intraarterial injection (vertebral artery), intrathecal injection, Horner’s syndrome, C8-Th1 sparing |
Supraclavicular (trunks and divisions) | Arm, forearm | Pneumothorax, diaphragmatic paralysis (phrenic nerve), bleeding (rich vasculature) |
Infraclavicular/Retroclavicular (cords) | Arm, forearm, hand | Pneumothorax, bleeding (noncompressible), discomfort during placement |
Axillary block (terminal branches) | Forearm, hand | Hematoma (superficial), musculocutaneous nerve spare (anterolateral aspect of forearm) |
The choice of technique is primarily dependent on the area of injury and surgery, but is also influenced by the inherent specific risks and individual patient anatomy. Logically, the proximal approaches (e.g., interscalene block) cover more predictably the proximal upper extremity (shoulder), whereas the more distal ones (e.g., axillary block) cover the forearm and hand more completely. Notably, the proximal part of the brachial plexus is in close proximity to many vital structures such as the phrenic nerve, vertebral artery, and pleura, and blocks at that level may be associated with rare, but serious complications such as pneumothorax, intraarterial injection or permanent hemidiaphragmatic paralysis. At the same time, transient deficits such as short-lived phrenic nerve block, Horner’s or voice hoarseness are common and usually tolerated well. Logically, the most distal approach, which still covers the surgical area, is usually chosen to avoid such complications (Table 47.1).
Beside specific complications, brachial plexus blocks still also carry the general risks of peripheral nerve blocks including nerve injury, systemic local anesthetic toxicity, infection, hematoma, pain/discomfort during the block, and block failure.
- 6.
Why most BPB are relatively contraindicated in severe pulmonary disease? What is the alternative choice of nerve block for postoperative analgesia?
Most proximal BPB approaches are associated with variable incidence of transient hemidiaphragmatic paralysis (phrenic nerve block), resulting in up to 30% reduction of pulmonary function [2]. Healthy individuals may experience mild shortness of breath, but usually tolerate these subclinical changes well. However, in patients with limited pulmonary reserve, such as severe COPD, this may lead to respiratory failure.
The interscalene brachial plexus block is associated with close to 100% incidence of hemidiaphragmatic paralysis. Even the supraclavicular and infraclavicular blocks are also associated with 34–50% and 14% reported incidence of hemidiaphragmatic block, respectively [3, 4]. The safest approach for patients with respiratory compromise is the axillary block, which carries no such risk. For shoulder surgery, a study showed that suprascapular nerve block provides significant shoulder analgesia and opioid sparing [5] without diaphragmatic function involvement. Even though its analgesic effect is not as complete as interscalene block, the suprascapular nerve block is a safe alternative technique for postoperative analgesia after shoulder surgery.
- 7.
What should be communicated with the surgical team before proceeding to the block? What are some relevant perioperative concerns?
Interdisciplinary communication is essential for best patient care. Specific details that should be addressed before the block (and before the case, in general) include:
Need for postoperative neurological tests, especially for fractures, surgical interventions, and hardware placement in immediate proximity to nerves and major blood vessels. If preexisting or iatrogenic nerve injury is a likely concern, the regional anesthesia block could be performed postoperatively, after a neurological examination. However, a postoperative block may be more challenging due to patient position, discomfort and cooperation, surgical dressing, and tissue edema. Preoperative catheter placement without local anesthetic injection and bolus with local anesthetics after the operation and satisfactory examination may be considered, especially in anatomically challenging patients.
Need for intraoperative nerve stimulation—sometimes, especially in cases where injury or/and subsequent scarring has disrupted normal anatomy, intraoperative nerve stimulation could be helpful in identifying nerve structures. Proximal plexus block does not impair the ability to obtain motor response from stimulation distal to the level of the block. Logically, in such cases, neuromuscular blockers should be avoided.
Concerns for postoperative acute compartment syndrome (ACS). Early signs and symptoms of acute compartment syndrome include disproportional pain, paresthesia, and paresis before developing limb ischemia. Neural blockade intends to produce analgesia, numbness and motor weakness—signs and symptoms similar to these of ACS, which may make such diagnosis more difficult. The anesthesiologist should discuss the specific risks and benefits with the surgical team, especially in high-risk patients, which include patients with fractures of leg or forearm, younger patients (age <35 years) and male patients [6, 7]. The use of peripheral nerve blocks for patients at risk for ACS remains controversial and is the subject of an ongoing debate. To mitigate the risks of “masking” warning signs and symptoms, nerve blocks should be followed by vigilant monitoring for ACS, including compartment pressure monitoring, and close communication with the surgical team should be maintained. Short-acting local anesthetics may be used for anesthesia/analgesia while allowing for rapid recovery of nerve function, continual testing, and monitoring. Low concentrations of local anesthetics should be used for analgesia to avoid “dense” motor blocks [8].Related posts:
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