Anesth Prog 37:258-260
CASE REPORT
Peripheral Nerve Injury During Anestiesia Stuart E. Lieblich, DMD Avon, Connecticut
A case is presented where a peripheral nerve injury occurred due to the pressure of a restraint buckle causing a postoperative motor and sensory deficit. Because these are iatrogenic injuries it is useful to review the mechanism of injury and means of prevention.
the foot. Anesthesia was present over the lateral and anterolateral aspect of the calf as well as the medial half of the foot. These findings were consistent with an injury to a peripheral nerve, specifically the common peroneal nerve. A neurologist was consulted on this case and a diagnosis of neuropraxia of the left common peroneal nerve was confirmed. Physical therapy was instituted and a foot support constructed to reduce the foot-drop tendencies. Within 2 months 95% of the function returned, and 12 months later no motor or sensory defect could be detected.
he anesthetized patient who is totally relaxed and unable to communicate with the anesthesiologist is at risk for iatrogenic injuries due to positioning trauma. Pressure upon nerves and blood vessels can cause injury due to ischemia over the course of a long surgical procedure. Because these types of injuries are avoidable it is instructive to review a case in which it occurred and to discuss means of prevention.
DISCUSSION There are two possible causes for the focal injury in this case. The nerve could have been traumatized during the surgical procedure to harvest the bone from the ilium. However, the nerves most frequently encountered during an iliac bone harvesting procedure are the sensory nerves to the skin overlying the gluteal muscle and anterior thigh (iliohypogastric nerves or subcostal branch of T-12). No motor deficits would be found following an injury to these nerves. The common peroneal nerve is a mixed motor and sensory nerve. It is a division of the sciatic nerve which runs very deep to the surgical site. As the sciatic nerve courses inferiorly it divides into two terminal branches; the tibial and common peroneal nerves. To rule out injury to the entire sciatic nerve, the patient was asked to flex his toes. Plantar flexion of the toes is carried by the tibial nerve, the other main branch of the sciatic. This function was intact in this case, therefore ruling out an injury to the entire sciatic nerve trunk. The common peroneal nerve and tibial nerves branch from the sciatic nerve along the dorsal surface of the thigh. The common peroneal nerve then moves from a dorsal to ventral location in the lower leg by crossing over the head of the fibula (Figure 1). At this location it is very susceptible to injury by pressure compressing the nerve against the head of the fibula causing ischemia to the nerve. 1 In the case presented the restraining belt on the opera-
CASE PRESENTATION A 22-year-old, ASA I male patient presented for a scheduled orthognathic procedure to correct his maxillary hypoplasia and mandibular prognathism. The surgical plan consisted of a LeForte I maxillary advancement, mandibular sagittal split osteotomies to set the mandible posteriorly and a bone graft to be harvested from the iliac crest. The anesthetic plan consisted of a nasotracheal intubation with controlled hypotension to reduce blood loss and improve surgical visibility. Two surgical teams were used: one to start on the facial bone surgery while the second team harvested the iliac bone. The surgery was completed in 5.5 hours without complications. On the first postoperative day the patient complained of numbness and weakness of the left leg with an inability to ambulate. A physical examination revealed a loss of dorsiflexion of the foot, along with the inability to evert Received May 12, 1989; accepted for publication May 25, 1990. Address correspondence to Stuart E. Lieblich, DMD, 34 Dale Road, Avon, CT 06001. C 1990 by the American Dental Society of Anesthesiology
ISSN 0003-3006/90/$3.50
258
Anesth Prog 37:258-260 1990
Lieblich 259
Figure 2. In the case presented, the metal buckle of the restraining belt was inadvertently placed lower than usual to permit access to obtain the iliac bone graft. Due to pressure from the buckle over the head of the fibula, the common peroneal nerve was compressed causing a postoperative motor and sensory deficit.
problems that could not be related to the surgery.2 These injuries may be caused by the position of the patient, pressure from the leaning on the patient by a member of a surgical team, or by a piece of equipment. Patients who are obese or very thin have an increased risk of injury. The obese patient can sustain peripheral nerve damage due to leaning against the patient by the surgical team to gain access or by compressing the nerves due to "packing" the patient onto a standard size operating tables and having to restrain the extremities tightly from rolling off the sides. Thin patients have a lesser thickness of protective tissues over bony prominences. Nerves crossing over these regions may be more easily compressed and therefore injured. Diabetic patients and those with preexisting peripheral
Figure 1. As the common peroneal nerve descends down the leg it moves from a dorsal position in the upper leg to a ventral position in the lower leg. It crosses the knee laterally over the head of the fibula. At that location it is suseptible to compression injury due to its superficial position over the bony structure.
ting table which is normally placed over the patient's thighs was moved inferiorly to allow preparation and access to the surgical site on the hip. The metal buckle of the belt came to rest directly over the head of the fibula causing compression injury to the nerve (Figure 2). This injury was probably exacerbated by pressure from the second surgical team against it leaning over to remove the graft from the hip. Injuries to peripheral nerves have been recognized since the 1890s when reports were made of postoperative
nerve disease are more suseptible to these injuries. As the oxygen supply to nerves in patients with anemia or arteriosclerosis is already reduced, any further compromise due to a positioning problem can cause a peripheral nerve injury. The use of hypotensive anesthesia has been documented as a cause of nerve ischemia3 and may have contributed to the severity of the injury in the case presented. Other causes of peripheral nerve injury need to be considered as well. For the traumatized patient, a full and careful neurologic examination may not be possible to perform preoperatively. Nerves injured in the initial accident should be noted as well as any suspected or possible injuries due to the sites of the trauma. The reasons for not doing a thorough examination should be specifically documented. Injuries to nerves are also reported following injections, venipuncture and spinal anesthetics.4 Although the common peroneal nerve is the most common nerve of the lower extremity to sustain this type of injury, the nerves of the brachial plexus are involved much more frequently.5 This is due to it being
Anesth Prog 37:258-260 1990
260 Nerve Injury During Anesthesia
a long, mobile, and relatively superficial nerve in close proximity to moveable bony structures (the head of the humerus and the clavicle). For example, abduction of the arm greater than 900 will compress the brachial artery in most individuals,6 causing ischemia to the nerves in the arm; as well as directly injuring the nerve through compression. If the patient is maintained in this position long enough, a residual motor nerve deficit will occur. This type of injury is noted in inebriated individuals who fall asleep on a park bench with their arm draped over the back of the bench. The alcohol level obtunds the normal painful stimulus of the ischemia and a permanent motor weakness is often the sequalae. A similar sequence of events can occur during general anesthesia if the arm position is not evaluated. During tuming of the patient the brachial nerve can be stretched if the scapula starts to move before the rest of the body. Therefore, the entire surgical team must move the patient together under the guidance and direction of the anesthesiologist to prevent nerve injuries, disconnections of tubes, dropping of the patient, and injury to the staff. This case illustrates that the anesthetized patient is totally reliant upon the anesthesiologist for proper positioning to prevent injury. A keen awareness is needed to ascertain that a peripheral nerve won't be compromised due to direct pressure or as a result of local tissue ischemia. Before the draping of the patient a survey of
the patient's position is indicated with padding of any potential pressure points. During the operation, the position of the surgical team should be monitored and they should be reminded not to lean on the patient. Because complications such as the case reported are preventable, a review and discussion of the etiology is useful to further improve the quality of care the patients receive.
ACKNOWLEDGEMENT The author acknowledges the neurologic consultation of Dr. Yolanda Pefia on this case.
REFERENCES 1. Solnitzky 0: Common peroneal nerve paralysis. Br J Surg 1953;41:300. 2. Garriques H: Anesthetic paralysis. Am J Md Sci 1897;1 13:81. 3. Lincoln JR, Sawyer HP: Complications related to body positions in surgical procedures. Anesthesiology 1961;22:800. 4. Lieblich SE, Topazian RG: Accidental intra-arterial injections. J Oral Max Surg 1988;46:297-302. 5. Jackson L, Keats AS: Mechanism of brachial plexus palsy following anesthesia. Anesthesiology 1965;26:190. 6. Weston B: Prevention of upper limb nerve injuries in Trendelenburg position. Acta Chir Scand 1954;108:61.
CASE REPORT
Peripheral Nerve Injury During Anestiesia Stuart E. Lieblich, DMD Avon, Connecticut
A case is presented where a peripheral nerve injury occurred due to the pressure of a restraint buckle causing a postoperative motor and sensory deficit. Because these are iatrogenic injuries it is useful to review the mechanism of injury and means of prevention.
the foot. Anesthesia was present over the lateral and anterolateral aspect of the calf as well as the medial half of the foot. These findings were consistent with an injury to a peripheral nerve, specifically the common peroneal nerve. A neurologist was consulted on this case and a diagnosis of neuropraxia of the left common peroneal nerve was confirmed. Physical therapy was instituted and a foot support constructed to reduce the foot-drop tendencies. Within 2 months 95% of the function returned, and 12 months later no motor or sensory defect could be detected.
he anesthetized patient who is totally relaxed and unable to communicate with the anesthesiologist is at risk for iatrogenic injuries due to positioning trauma. Pressure upon nerves and blood vessels can cause injury due to ischemia over the course of a long surgical procedure. Because these types of injuries are avoidable it is instructive to review a case in which it occurred and to discuss means of prevention.
DISCUSSION There are two possible causes for the focal injury in this case. The nerve could have been traumatized during the surgical procedure to harvest the bone from the ilium. However, the nerves most frequently encountered during an iliac bone harvesting procedure are the sensory nerves to the skin overlying the gluteal muscle and anterior thigh (iliohypogastric nerves or subcostal branch of T-12). No motor deficits would be found following an injury to these nerves. The common peroneal nerve is a mixed motor and sensory nerve. It is a division of the sciatic nerve which runs very deep to the surgical site. As the sciatic nerve courses inferiorly it divides into two terminal branches; the tibial and common peroneal nerves. To rule out injury to the entire sciatic nerve, the patient was asked to flex his toes. Plantar flexion of the toes is carried by the tibial nerve, the other main branch of the sciatic. This function was intact in this case, therefore ruling out an injury to the entire sciatic nerve trunk. The common peroneal nerve and tibial nerves branch from the sciatic nerve along the dorsal surface of the thigh. The common peroneal nerve then moves from a dorsal to ventral location in the lower leg by crossing over the head of the fibula (Figure 1). At this location it is very susceptible to injury by pressure compressing the nerve against the head of the fibula causing ischemia to the nerve. 1 In the case presented the restraining belt on the opera-
CASE PRESENTATION A 22-year-old, ASA I male patient presented for a scheduled orthognathic procedure to correct his maxillary hypoplasia and mandibular prognathism. The surgical plan consisted of a LeForte I maxillary advancement, mandibular sagittal split osteotomies to set the mandible posteriorly and a bone graft to be harvested from the iliac crest. The anesthetic plan consisted of a nasotracheal intubation with controlled hypotension to reduce blood loss and improve surgical visibility. Two surgical teams were used: one to start on the facial bone surgery while the second team harvested the iliac bone. The surgery was completed in 5.5 hours without complications. On the first postoperative day the patient complained of numbness and weakness of the left leg with an inability to ambulate. A physical examination revealed a loss of dorsiflexion of the foot, along with the inability to evert Received May 12, 1989; accepted for publication May 25, 1990. Address correspondence to Stuart E. Lieblich, DMD, 34 Dale Road, Avon, CT 06001. C 1990 by the American Dental Society of Anesthesiology
ISSN 0003-3006/90/$3.50
258
Anesth Prog 37:258-260 1990
Lieblich 259
Figure 2. In the case presented, the metal buckle of the restraining belt was inadvertently placed lower than usual to permit access to obtain the iliac bone graft. Due to pressure from the buckle over the head of the fibula, the common peroneal nerve was compressed causing a postoperative motor and sensory deficit.
problems that could not be related to the surgery.2 These injuries may be caused by the position of the patient, pressure from the leaning on the patient by a member of a surgical team, or by a piece of equipment. Patients who are obese or very thin have an increased risk of injury. The obese patient can sustain peripheral nerve damage due to leaning against the patient by the surgical team to gain access or by compressing the nerves due to "packing" the patient onto a standard size operating tables and having to restrain the extremities tightly from rolling off the sides. Thin patients have a lesser thickness of protective tissues over bony prominences. Nerves crossing over these regions may be more easily compressed and therefore injured. Diabetic patients and those with preexisting peripheral
Figure 1. As the common peroneal nerve descends down the leg it moves from a dorsal position in the upper leg to a ventral position in the lower leg. It crosses the knee laterally over the head of the fibula. At that location it is suseptible to compression injury due to its superficial position over the bony structure.
ting table which is normally placed over the patient's thighs was moved inferiorly to allow preparation and access to the surgical site on the hip. The metal buckle of the belt came to rest directly over the head of the fibula causing compression injury to the nerve (Figure 2). This injury was probably exacerbated by pressure from the second surgical team against it leaning over to remove the graft from the hip. Injuries to peripheral nerves have been recognized since the 1890s when reports were made of postoperative
nerve disease are more suseptible to these injuries. As the oxygen supply to nerves in patients with anemia or arteriosclerosis is already reduced, any further compromise due to a positioning problem can cause a peripheral nerve injury. The use of hypotensive anesthesia has been documented as a cause of nerve ischemia3 and may have contributed to the severity of the injury in the case presented. Other causes of peripheral nerve injury need to be considered as well. For the traumatized patient, a full and careful neurologic examination may not be possible to perform preoperatively. Nerves injured in the initial accident should be noted as well as any suspected or possible injuries due to the sites of the trauma. The reasons for not doing a thorough examination should be specifically documented. Injuries to nerves are also reported following injections, venipuncture and spinal anesthetics.4 Although the common peroneal nerve is the most common nerve of the lower extremity to sustain this type of injury, the nerves of the brachial plexus are involved much more frequently.5 This is due to it being
Anesth Prog 37:258-260 1990
260 Nerve Injury During Anesthesia
a long, mobile, and relatively superficial nerve in close proximity to moveable bony structures (the head of the humerus and the clavicle). For example, abduction of the arm greater than 900 will compress the brachial artery in most individuals,6 causing ischemia to the nerves in the arm; as well as directly injuring the nerve through compression. If the patient is maintained in this position long enough, a residual motor nerve deficit will occur. This type of injury is noted in inebriated individuals who fall asleep on a park bench with their arm draped over the back of the bench. The alcohol level obtunds the normal painful stimulus of the ischemia and a permanent motor weakness is often the sequalae. A similar sequence of events can occur during general anesthesia if the arm position is not evaluated. During tuming of the patient the brachial nerve can be stretched if the scapula starts to move before the rest of the body. Therefore, the entire surgical team must move the patient together under the guidance and direction of the anesthesiologist to prevent nerve injuries, disconnections of tubes, dropping of the patient, and injury to the staff. This case illustrates that the anesthetized patient is totally reliant upon the anesthesiologist for proper positioning to prevent injury. A keen awareness is needed to ascertain that a peripheral nerve won't be compromised due to direct pressure or as a result of local tissue ischemia. Before the draping of the patient a survey of
the patient's position is indicated with padding of any potential pressure points. During the operation, the position of the surgical team should be monitored and they should be reminded not to lean on the patient. Because complications such as the case reported are preventable, a review and discussion of the etiology is useful to further improve the quality of care the patients receive.
ACKNOWLEDGEMENT The author acknowledges the neurologic consultation of Dr. Yolanda Pefia on this case.
REFERENCES 1. Solnitzky 0: Common peroneal nerve paralysis. Br J Surg 1953;41:300. 2. Garriques H: Anesthetic paralysis. Am J Md Sci 1897;1 13:81. 3. Lincoln JR, Sawyer HP: Complications related to body positions in surgical procedures. Anesthesiology 1961;22:800. 4. Lieblich SE, Topazian RG: Accidental intra-arterial injections. J Oral Max Surg 1988;46:297-302. 5. Jackson L, Keats AS: Mechanism of brachial plexus palsy following anesthesia. Anesthesiology 1965;26:190. 6. Weston B: Prevention of upper limb nerve injuries in Trendelenburg position. Acta Chir Scand 1954;108:61.
