Acta Anaesthesiol Scand 1992: 36: 53-57
Effect of continuous interscalene brachial plexus block on diaphragm motion and on ventilatory function P. PERE,M. PITKANEN, P. H. ROSENBERG, J.-M. BJORKENHEIM,H. LINDEN,Y. SALORINNE and M. TUOMINEN Departments of Anaesthesia and Orthopaedic Surgery, Surgical Hospital, Helsinki University Central Hospital, and Department of Clinical Physiology, Helsinki City Hospital, Helsinki, Finland
Interscalene block may cause phrenic nerve block and decreased diaphragmatic motion. We evaluated the efPect of continuous interscalene block on ventilatory function and diaphragmatic motion. We studied ten patients scheduled for surgery or manipulation of the shoulder. Preoperatively, the patients underwent spirometry and double-exposure chest radiography. They received an interscalene block with 0.75% bupivacaine. Thereafter, 0.25% bupivacaine was infused into the interscalene space for 24 h. Spirometry was repeated three times and double-exposure radiography twice. The maximal inspiratory and expiratory pressures were measured repeatedly. Haemoglobin oxygen saturation (SPo,) was monitored with pulse oximetry. The block provided adequate anaesthesia for surgery or manipulation. All patients had a marked ipsilateral paresis of the diaphragm in the radiographs 3 h after the initial block. Twenty-one hours later five patients had diaphragmatic motility comparable to the situation before the block. In the other five patients, the amplitude of diaphragmatic motility on the side of the block was only 6 3 7 % of the values before the block. All patients had a clear reduction in forced vital capacity (FVC), forced expiratory volume in Is (FEV,) and peak expiratory flow (PEF) 3 and 8 h after the block without signs ofdyspnoea. In conclusion, in all our patients interscalene block caused an ipsilateral hemidiaphragm paresis, which in five of ten patients persisted until the end of the continuous block.
Receiued 15 February, accepted for publication 25 May 1991
Key words: Anesthetics, local: bupivacaine; anesthetic techniques, regional: intencalene brachial plexus block; diaphragm: paresis.
Diaphragmatic paresis due to phrenic nerve block has been a known side-effect of brachial plexus block since the reports of Hartel & Keppler (1) in 1913 and Kulenkampff & Persky (2) in 1928. Recently, Urmey et al. (3) reported a 100% incidence of ipsilateral hemidiaphragm paresis in 12 patients 5 min after injection of a local anaesthetic for an interscalene brachial plexus block. The block caused detectable deterioriation of pulmonary function (4). In a healthy patient at rest, however, this is usually asymptomatic. When a single injection technique is used, the diaphragmatic paresis may disappear earlier than the block of the extremity (5). In our hospital, continuous interscalene brachial plexus block with bupivacaine has been found effective for analgesia during shoulder surgery and for postoperative pain relief (6, 7 ) . The effect of continuous interscalene brachial plexus block on diaphragmatic movement and ventilatory function has not been studied ,
PATIENTS AND METHODS The study protocol was approved by the Ethics Committee of the hospital. Ten patients (Table 1) scheduled for orthopaedic surgery or manipulation of the shoulder gave their informed consent. The patients were prernedicated with diazepam 0.2 mg kg- orally and oxycodone 0.15 mg kg-' i.m. 1-2 h before the block. The brachial plexus was identified using a nerve stimulator (DualStim@, Life-Tech Inc., Houston, Texas) connected to the proximal end of the metal inner needle of a plastic cannula (Contiplex@,B. BraunMelsungen AG, FRG)using the interscalene approach. Bupivacaine 0.75% with adrenaline 5 pg ml-I, 20-28 ml according to the patient's weight, was then injected through the plastic cannula. A catheter (Contiplexm,0.d. 0.85 mm) was then introduced into the interscalene space and fixed to the skin with a tight suture. An infusion (5-9 ml h-') of 0.25% bupivacaine without adrenaline was started and continued for 24 h. The suprascapular nerve and the intercostobrachial nerves were blocked with a local infiltration of 4 and 5 ml of 0.5% bupivacaine with adrenaline, respectively. Non-invasively measured arterial systolic and diastolic blood pressures and heart rates were recorded at 5-min intervals during surgery and at 10-min intervals in the recovery room. ECG was continuously monitored. Ringer's acetated solution was given i.v. 3-4 ml kg-' h - ' during surgery and 1-1.5 ml kg-' h-' in the postoperative period.
54
P. PERE E T AL.
Tahle I Characteristics of the patients. Patient number
Age
Height
Weight
(yr)
(cm)
(kg)
Operation
49 M 48 F 45 M 42 M 33 F 57 M 51 F 41 M 44 F 4 4
172 I67 163 I78 I79 160 177 153 173 166
72 76 66 85 125 68 75 53 96 98
1 1 1
Sex
F
I 2 3 4 5 6 7 8 9 10
(fentanyl 100 pg and alfentanil 1 .O mg) during surgery. The same patients needed oxycodone for postoperative pain relief - the first patient once and the other twice in 24 h. None of the patients complained of dyspnoea.
2 I 1 1
2 2 2
~~
I
=
Anterior acromioplasty, 2
=
Manipulation.
The extent of the block was tested at 10-min intervals for 30 min and again 2, 3, and 8 h after the beginning of the block and at the end of the 24-h infusion.
Respiratoy tests On the preoprrative day, the patients underwent spirometry and double-exposure chest radiography (exposures after deep inspiration and expiration on thr same film). During spirometry the patients werr sitting. The radiographs were taken with the patients supine in ordrr to document the effect of increased intraabdominal pressure on the diaphragm. The maximal inspiratory and expiratory pressures the patient could maintain for 3 s were measured using a simple pressure gauge (Spirao, Hengityshoitokeskus, Hameenlinna, Finland) on tho preoperative day, just before the block, and 10, 20, and 30 min, and 2, 3, 8, and 24 h after the initial block. Spirometry was repeated 3, 8, and 24 h and double-exposure radiography 3 and 24 h after the block. The tests on the first postoperative day were made as soon as technically possible after the discontinuation of the infusion of bupivacaine into the interscalene space. The amplitude of the diaphragmatic movement was measured from the radiographs on a line drawn caudally from the lateral end of the medial third of the clavicle parallel to the spine. The oxygen saturation in arterial blood (SPo,) was measured continuously (Ohmeda BIOX 3700e" pulse oximeter, Ohmeda Inc., Louisville, USA) from a finger of the blocked extremity and recorded on paper (Ohmrda" pen recorder). Statistical analyzis Differcnces between the mean values were analysed using paired Student's t-test. P < 0.05 was considered statistically significant.
RESULTS The interscalene brachial plexus block gave adequate analgesia for surgery or manipulation of the shoulder in all patients. Tested with pinprick 20 min after injection of 0.75% bupivacaine, four patients had anaesthesia and six patients analgesia of the skin innervated by the supraclavicular and axillary nerves. Postoperatively, 2 h after the initial block, all patients had anaesthesia in the innervation area of the supraclavicular and nine patients anaesthesia and One by the axillary nerve* in the skin patients (no. 6 and no. 7) were given short-acting opioids
Fig. I . Double-exposure chest radiographs (a) before, (b) 3 h after, and (c) 24 h after the beginning of a continuous interscalene brachial plexus block. The arrows point at the diaphragm after maximal expiration.
55
DIAPHRAGM PARESIS DURING INTERSCALENE BLOCK
In the pulse oximetry recordings of three patients (no. 5, 9, l o ) , short periods of less than 1 min of low saturation (81-85%) were observed during the postoperative night. One patient (no. 7) had recurrent periods of decreased haemoglobin saturation 6-8 h after the operation. This patient had normal SPo, during the postoperative night. The two patients (no. 5 and no. 10) who had the lowest saturations were obese (Table 1). All ten patients had an ipsilateral paresis of the diaphragm in the chest radiographs 3 h after the block (Fig. 1, Table 2). The amplitude of the diaphragmatic movement was 5-32% (mean 12%) of the preoperative values on the side of the block (P
Effect of continuous interscalene brachial plexus block on diaphragm motion and on ventilatory function P. PERE,M. PITKANEN, P. H. ROSENBERG, J.-M. BJORKENHEIM,H. LINDEN,Y. SALORINNE and M. TUOMINEN Departments of Anaesthesia and Orthopaedic Surgery, Surgical Hospital, Helsinki University Central Hospital, and Department of Clinical Physiology, Helsinki City Hospital, Helsinki, Finland
Interscalene block may cause phrenic nerve block and decreased diaphragmatic motion. We evaluated the efPect of continuous interscalene block on ventilatory function and diaphragmatic motion. We studied ten patients scheduled for surgery or manipulation of the shoulder. Preoperatively, the patients underwent spirometry and double-exposure chest radiography. They received an interscalene block with 0.75% bupivacaine. Thereafter, 0.25% bupivacaine was infused into the interscalene space for 24 h. Spirometry was repeated three times and double-exposure radiography twice. The maximal inspiratory and expiratory pressures were measured repeatedly. Haemoglobin oxygen saturation (SPo,) was monitored with pulse oximetry. The block provided adequate anaesthesia for surgery or manipulation. All patients had a marked ipsilateral paresis of the diaphragm in the radiographs 3 h after the initial block. Twenty-one hours later five patients had diaphragmatic motility comparable to the situation before the block. In the other five patients, the amplitude of diaphragmatic motility on the side of the block was only 6 3 7 % of the values before the block. All patients had a clear reduction in forced vital capacity (FVC), forced expiratory volume in Is (FEV,) and peak expiratory flow (PEF) 3 and 8 h after the block without signs ofdyspnoea. In conclusion, in all our patients interscalene block caused an ipsilateral hemidiaphragm paresis, which in five of ten patients persisted until the end of the continuous block.
Receiued 15 February, accepted for publication 25 May 1991
Key words: Anesthetics, local: bupivacaine; anesthetic techniques, regional: intencalene brachial plexus block; diaphragm: paresis.
Diaphragmatic paresis due to phrenic nerve block has been a known side-effect of brachial plexus block since the reports of Hartel & Keppler (1) in 1913 and Kulenkampff & Persky (2) in 1928. Recently, Urmey et al. (3) reported a 100% incidence of ipsilateral hemidiaphragm paresis in 12 patients 5 min after injection of a local anaesthetic for an interscalene brachial plexus block. The block caused detectable deterioriation of pulmonary function (4). In a healthy patient at rest, however, this is usually asymptomatic. When a single injection technique is used, the diaphragmatic paresis may disappear earlier than the block of the extremity (5). In our hospital, continuous interscalene brachial plexus block with bupivacaine has been found effective for analgesia during shoulder surgery and for postoperative pain relief (6, 7 ) . The effect of continuous interscalene brachial plexus block on diaphragmatic movement and ventilatory function has not been studied ,
PATIENTS AND METHODS The study protocol was approved by the Ethics Committee of the hospital. Ten patients (Table 1) scheduled for orthopaedic surgery or manipulation of the shoulder gave their informed consent. The patients were prernedicated with diazepam 0.2 mg kg- orally and oxycodone 0.15 mg kg-' i.m. 1-2 h before the block. The brachial plexus was identified using a nerve stimulator (DualStim@, Life-Tech Inc., Houston, Texas) connected to the proximal end of the metal inner needle of a plastic cannula (Contiplex@,B. BraunMelsungen AG, FRG)using the interscalene approach. Bupivacaine 0.75% with adrenaline 5 pg ml-I, 20-28 ml according to the patient's weight, was then injected through the plastic cannula. A catheter (Contiplexm,0.d. 0.85 mm) was then introduced into the interscalene space and fixed to the skin with a tight suture. An infusion (5-9 ml h-') of 0.25% bupivacaine without adrenaline was started and continued for 24 h. The suprascapular nerve and the intercostobrachial nerves were blocked with a local infiltration of 4 and 5 ml of 0.5% bupivacaine with adrenaline, respectively. Non-invasively measured arterial systolic and diastolic blood pressures and heart rates were recorded at 5-min intervals during surgery and at 10-min intervals in the recovery room. ECG was continuously monitored. Ringer's acetated solution was given i.v. 3-4 ml kg-' h - ' during surgery and 1-1.5 ml kg-' h-' in the postoperative period.
54
P. PERE E T AL.
Tahle I Characteristics of the patients. Patient number
Age
Height
Weight
(yr)
(cm)
(kg)
Operation
49 M 48 F 45 M 42 M 33 F 57 M 51 F 41 M 44 F 4 4
172 I67 163 I78 I79 160 177 153 173 166
72 76 66 85 125 68 75 53 96 98
1 1 1
Sex
F
I 2 3 4 5 6 7 8 9 10
(fentanyl 100 pg and alfentanil 1 .O mg) during surgery. The same patients needed oxycodone for postoperative pain relief - the first patient once and the other twice in 24 h. None of the patients complained of dyspnoea.
2 I 1 1
2 2 2
~~
I
=
Anterior acromioplasty, 2
=
Manipulation.
The extent of the block was tested at 10-min intervals for 30 min and again 2, 3, and 8 h after the beginning of the block and at the end of the 24-h infusion.
Respiratoy tests On the preoprrative day, the patients underwent spirometry and double-exposure chest radiography (exposures after deep inspiration and expiration on thr same film). During spirometry the patients werr sitting. The radiographs were taken with the patients supine in ordrr to document the effect of increased intraabdominal pressure on the diaphragm. The maximal inspiratory and expiratory pressures the patient could maintain for 3 s were measured using a simple pressure gauge (Spirao, Hengityshoitokeskus, Hameenlinna, Finland) on tho preoperative day, just before the block, and 10, 20, and 30 min, and 2, 3, 8, and 24 h after the initial block. Spirometry was repeated 3, 8, and 24 h and double-exposure radiography 3 and 24 h after the block. The tests on the first postoperative day were made as soon as technically possible after the discontinuation of the infusion of bupivacaine into the interscalene space. The amplitude of the diaphragmatic movement was measured from the radiographs on a line drawn caudally from the lateral end of the medial third of the clavicle parallel to the spine. The oxygen saturation in arterial blood (SPo,) was measured continuously (Ohmeda BIOX 3700e" pulse oximeter, Ohmeda Inc., Louisville, USA) from a finger of the blocked extremity and recorded on paper (Ohmrda" pen recorder). Statistical analyzis Differcnces between the mean values were analysed using paired Student's t-test. P < 0.05 was considered statistically significant.
RESULTS The interscalene brachial plexus block gave adequate analgesia for surgery or manipulation of the shoulder in all patients. Tested with pinprick 20 min after injection of 0.75% bupivacaine, four patients had anaesthesia and six patients analgesia of the skin innervated by the supraclavicular and axillary nerves. Postoperatively, 2 h after the initial block, all patients had anaesthesia in the innervation area of the supraclavicular and nine patients anaesthesia and One by the axillary nerve* in the skin patients (no. 6 and no. 7) were given short-acting opioids
Fig. I . Double-exposure chest radiographs (a) before, (b) 3 h after, and (c) 24 h after the beginning of a continuous interscalene brachial plexus block. The arrows point at the diaphragm after maximal expiration.
55
DIAPHRAGM PARESIS DURING INTERSCALENE BLOCK
In the pulse oximetry recordings of three patients (no. 5, 9, l o ) , short periods of less than 1 min of low saturation (81-85%) were observed during the postoperative night. One patient (no. 7) had recurrent periods of decreased haemoglobin saturation 6-8 h after the operation. This patient had normal SPo, during the postoperative night. The two patients (no. 5 and no. 10) who had the lowest saturations were obese (Table 1). All ten patients had an ipsilateral paresis of the diaphragm in the chest radiographs 3 h after the block (Fig. 1, Table 2). The amplitude of the diaphragmatic movement was 5-32% (mean 12%) of the preoperative values on the side of the block (P
