British JuurnolufUrulugy (1991), 68, 18-24 01991 British Journal of Urology
Anaesthesia-free Extracorporeal Shock Wave Lithotripsy in Patients with Renal Calculi H. VANDEURSEN, B. TJANDRAMAGA, R. VERBESSELT, G. SMET and L. BAERT Department of Urology, University Hospital Sint- Pieter; Department of Clinical Pharmacology, University Hospital Gasthuisberg,L euven, Belgium
Summary-Modern extracorporeal shock wave lithotripsy can be performed with combined ECG and respiratory triggered shock wave release. Disconnecting the ECG triggering increases the risk of ventricular arrhythmias, including potentially malignant ones. The aim of this study was to assess the relationship of any sympatho-adrenal excitation as a possible explanation for the occurrence of cardiac arrhythmia. Plasma catecholamine levels were assessed in 5 patients during and after 50 min of anaesthesiafree extracorporeal shock wave lithotripsy for the treatment of calculi in the upper pole of the left kidney. Venous blood sampling showed no significant increase in catecholamines (epinephrine, norepinephrine and dopamine) during or after treatment. The heart rate and arterial blood pressure were measured simultaneously and showed no significant increase when shock waves were released during ECG triggering. However, when disconnecting the ECG-triggering mode, the incidence of ventricular extrasystoles on Holter monitoring became more apparent during respiratory triggered shock wave release only, although there was no rise in plasma catecholamine levels. These data suggest that cardiac arrhythmias are related to direct and accidental mechanical stimulation of the heart rather than to any sympatho-adrenal discharge during shock wave release.
throughout the urinary tract can be performed regardless of their location, since patients can be installed comfortably in both the prone and supine position. It is felt that stone composition rather than size or location is more important in determining the success of ESWL treatment. Earlier experience with the first generation extracorporeal shock wave lithotriptors reported an incidence of arrhythmia of 80% during the procedure, even when focusing perfectly on the stone (Chaussy and Schmiedt, 1983). Shock wave release 20 ms after the R-wave of the patient’s electrocardiographic course (ECG triggered mode), as is possible with the modern lithotriptors, eliminates the risk of occurrence of extrasystoles if the shock waves should inadvertantly hit the cardiac region during the vulnerable T-phase (Ector et al., 1989). Respiratory triggering is now also performed
Since its introduction in the early eighties (Chaussy et al., 1982), extracorporeal shock wave lithotripsy (ESWL) (Dornier Medical Systems, Marietta, USA) has become the treatment of choice in patients with urinary tract calculi. ESWL began in June 1987 with the Siemens Lithostar (Siemens Medical Engineering Group, Erlangen, Germany); 7500 procedures had been carried out by April 1990. These were performed without anaesthesia on an out-patient basis. The low invasiveness of the Lithostar is mainly related to the pressure amplitudes of the generated shock waves (Folberth, 1989). This allows treatment of larger stones as multiple staged procedures can be carried out with low morbidity. Successful monotherapy was achieved in larger stone volumes (Vandeursen and Baert, 1990a and b) and treatment of calculi Accepted for publication 20 November 1990
18
19
ANAESTHESIA-FREE ESWL
in the renal and upper ureteric locations; shock waves are released during expiration only, not only to target the stone perfectly but also to lower the risk of accidental firing on the lungs or heart. We wished to study catecholamine plasma levels when shock waves were applied to the left upper pole of the kidney; the vicinity of this location near both heart and adrenal gland is ideal because the effect of the shock wave on both organs can induce arrhythmia. Assessing both the cardiac rhythm and the plasma catecholamine levels is relevant for the origin of arrhythmia occurring during ESWL. Either sympatho-adrenal stimulation or direct heart excitation by the shock wave itself can then be distinguished as a cause of the arrhythmia.
Patients and Methods In 5 patients scheduled for ESWL, plasma catecholamine levels were assessed before, during and after treatment. The calculi were all located in the upper pole of the left kidney. The group comprised 4 males and 1 female, aged between 46 and 70 years (mean 49). None had a history of cardiovascular disorder or cardiac arrhythmia, except for mild arterial hypertension in 3 cases controlled by dietary restrictions. None of the patients had received medication specifically affecting the sympathetic nervous system. All patients were treated with the Lithostar without anaesthesia. Only mild sedation with a benzodiazepine (1 mg lorazepam) was administered orally approximately 30 rnin before the start of treatment. ESWL was started in the combined ECG and respiratory triggered mode, but at certain moments the ECG triggering was discontinued. Shock wave electrical discharge ranged from 16 to 19 kV and the number of shock waves per kidney and per session ranged to 3000. Heart rate and arterial blood pressure were recorded at each blood sampling time. Holter monitoring (Oxford Medilog 4000-11 recorder) was initiated 30 rnin before lithotripsy and was continued for 30 rnin after the procedure. Venous blood sampling for plasma catecholamine assay by high performance liquid chromatography with electrochemical detection (Bauensfeld et al., 1984) was carried out at the following times: baseline control values 10 and 5 rnin before and at the start of ESWL (TO, T5, TlO), during the procedure after 10, 20, 30,40 and 50 rnin of shock wave applications (T20, T30, T40, T50 and T60) and thereafter 5, 10, 15 and 20 rnin (T65, T70, T75 and T80) after stopping treatment.
During the control baseline period all patients were positioned on the Lithostar table 10min before sampling in order to avoid sympathetic stimulation by stress apart from a possible ESWL-related catecholamine release by stimulation of the adrenal medulla.
Results Individual plasma catecholamine concentrations were recorded, including norepinephrine, epinephrine and dopamine (Tables 1, 2 and 3). The upper limits of normal reference values for the 3 catecholamines were : norepinephrine 300 ng/l, epinephrine 150ng/l and dopamine 100ng/l. The mean catecholamine profiles before, during and after ESWL are shown in Figure 1; no significant change in plasma levels of norepinephrine, epinephrine or dopamine was observed during or after the procedure in any of the 5 patients. Tables 4 and 5 reveal no significant changes in arterial blood pressure or heart rate (Figs 2 and 3). Holter monitoring revealed no cardiac arrhythmia with combined ECG and respiratory triggered shock wave release. When firing with only respiratory triggering, solitary ventricular extrasystoles occurred in 2 patients ; all were symptomatic and transient.
Discussion When compared with the baseline control values, no increase in the plasma concentrations of norepinephrine, epinephrine or dopamine was observed during or after lithotripsy. The mean baseline values of norepinephrine ranged between 370 and 470 ng/l before lithotripsy, which is slightly higher than the upper limit of the normal range : this may be related to the “non-basal” conditions due to emotional stress in the patients during the whole treatment period. However, it is interesting to note the absence of any increase during the procedure with repeated shock wave applications (Fig. 1). When carried out in the combined ECG and respiratory triggered mode, no increase in heart rate or blood pressure was found and no rhythmic disorder was noted in any patient. The absence of any significant increase in plasma catecholamine levels together with the lack of cardiac arrhythmia or extrasystoles, or changes in arterial pressure during combined respiratory and ECG triggered shock wave release, indicates that the influence of ESWL on cardiac activity reported by Chaussy and Schmiedt (1983) and Ector et al. (1989) may be related to direct cardiac excitation
20
BRITISH JOURNAL OF UROLOGY
Table 1 Individual Plasma Norepinephrine Levels (ng/l)
TO T5 T10 T20 T30 T40 T50 T60 T65 T70 T75 T80
Patient I (male, 62 years)
Patient (male. 61 years)
Patient 3 (female, 47 years)
Patient 4 (male, 57 years)
Patient 5 (male, 77 years)
Average
470 489 578 510 542 505 466 579 516 415 450 418
404 361 512 362 39 1 406 508 569 482 530 514 488
246 290 301 251 266 190 127 129 137 195 196 178
361 490 440 595 476 370 390 299 370 448 350 433
417 462 492 497 519 515 492 443 441 420 413 396
379.6 418 464 443 438.8 397.2 396.6 403.8 389.2 401.6 384.6 379.2
Patient 4 (male, 57 years)
Patient 5 (male, 77 years)
Average
SD
101 22 44 19 26 17 25 70 34 51 26 26
128 128 131 107 93 118 115 133 125 131 142 123
72.8 55.4 83.4 49.2 54.6 50.6 58.4 69.8 47.8 54.4 55.6 52.4
141.2
Patient 3 (female, 47 years)
Patient 4 (male, 57 years)
Patient 5 (male, 77 years)
Average
SD
< 25 < 25 < 25 < 25 < 25 < 25 < 25 < 25 < 25 < 25 < 25 < 25
< 25
< 25
25 25 25 25 25 25 25 25 25 51 25
< 25 < 25 < 25 < 25 < 25 < 25 < 25 < 25 < 25 95 < 25
32.2 42 37.8 25 36 30.6 39.2 44.8 36 37.8 44.2 37.4
f 16.0 f23.4
SD f 84.2 f 89.1
+ 103.9
7 135.9 f112.4
f 131.5 f 157.3 & 191
f151.1 f 124.3 & 121 f 137
Table 2 Individual Plasma Epinephrine Levels (ng/l) Patient I (male, 62 years)
TO T5 T10 T20 T30 T40 T50 T60 T65 T70 T75 T80
62 80 176 70 94 53 112 97 41 46 49 63
Patient 2 (male, 61 years)
47
< 25 48 24 35 25 < 25 < 25 < 25 < 25 41 25
Patient 3 (female, 47 years)
26 22 18 < 25 < 25 40 15 24 14 19 20 < 25
f47.5 f66.9 f38.4 + 35.7 40.1 f50 k47.0 f44.3
144.9 f49.6 f 42.7
Table 3 Individual Plasma Dopamine Levels (ng/l) Patient I (male, 62 years)
TO T5 TI0 T20 T30 T40 T50 T60 T65 T70 T75 T80
Anaesthesia-free Extracorporeal Shock Wave Lithotripsy in Patients with Renal Calculi H. VANDEURSEN, B. TJANDRAMAGA, R. VERBESSELT, G. SMET and L. BAERT Department of Urology, University Hospital Sint- Pieter; Department of Clinical Pharmacology, University Hospital Gasthuisberg,L euven, Belgium
Summary-Modern extracorporeal shock wave lithotripsy can be performed with combined ECG and respiratory triggered shock wave release. Disconnecting the ECG triggering increases the risk of ventricular arrhythmias, including potentially malignant ones. The aim of this study was to assess the relationship of any sympatho-adrenal excitation as a possible explanation for the occurrence of cardiac arrhythmia. Plasma catecholamine levels were assessed in 5 patients during and after 50 min of anaesthesiafree extracorporeal shock wave lithotripsy for the treatment of calculi in the upper pole of the left kidney. Venous blood sampling showed no significant increase in catecholamines (epinephrine, norepinephrine and dopamine) during or after treatment. The heart rate and arterial blood pressure were measured simultaneously and showed no significant increase when shock waves were released during ECG triggering. However, when disconnecting the ECG-triggering mode, the incidence of ventricular extrasystoles on Holter monitoring became more apparent during respiratory triggered shock wave release only, although there was no rise in plasma catecholamine levels. These data suggest that cardiac arrhythmias are related to direct and accidental mechanical stimulation of the heart rather than to any sympatho-adrenal discharge during shock wave release.
throughout the urinary tract can be performed regardless of their location, since patients can be installed comfortably in both the prone and supine position. It is felt that stone composition rather than size or location is more important in determining the success of ESWL treatment. Earlier experience with the first generation extracorporeal shock wave lithotriptors reported an incidence of arrhythmia of 80% during the procedure, even when focusing perfectly on the stone (Chaussy and Schmiedt, 1983). Shock wave release 20 ms after the R-wave of the patient’s electrocardiographic course (ECG triggered mode), as is possible with the modern lithotriptors, eliminates the risk of occurrence of extrasystoles if the shock waves should inadvertantly hit the cardiac region during the vulnerable T-phase (Ector et al., 1989). Respiratory triggering is now also performed
Since its introduction in the early eighties (Chaussy et al., 1982), extracorporeal shock wave lithotripsy (ESWL) (Dornier Medical Systems, Marietta, USA) has become the treatment of choice in patients with urinary tract calculi. ESWL began in June 1987 with the Siemens Lithostar (Siemens Medical Engineering Group, Erlangen, Germany); 7500 procedures had been carried out by April 1990. These were performed without anaesthesia on an out-patient basis. The low invasiveness of the Lithostar is mainly related to the pressure amplitudes of the generated shock waves (Folberth, 1989). This allows treatment of larger stones as multiple staged procedures can be carried out with low morbidity. Successful monotherapy was achieved in larger stone volumes (Vandeursen and Baert, 1990a and b) and treatment of calculi Accepted for publication 20 November 1990
18
19
ANAESTHESIA-FREE ESWL
in the renal and upper ureteric locations; shock waves are released during expiration only, not only to target the stone perfectly but also to lower the risk of accidental firing on the lungs or heart. We wished to study catecholamine plasma levels when shock waves were applied to the left upper pole of the kidney; the vicinity of this location near both heart and adrenal gland is ideal because the effect of the shock wave on both organs can induce arrhythmia. Assessing both the cardiac rhythm and the plasma catecholamine levels is relevant for the origin of arrhythmia occurring during ESWL. Either sympatho-adrenal stimulation or direct heart excitation by the shock wave itself can then be distinguished as a cause of the arrhythmia.
Patients and Methods In 5 patients scheduled for ESWL, plasma catecholamine levels were assessed before, during and after treatment. The calculi were all located in the upper pole of the left kidney. The group comprised 4 males and 1 female, aged between 46 and 70 years (mean 49). None had a history of cardiovascular disorder or cardiac arrhythmia, except for mild arterial hypertension in 3 cases controlled by dietary restrictions. None of the patients had received medication specifically affecting the sympathetic nervous system. All patients were treated with the Lithostar without anaesthesia. Only mild sedation with a benzodiazepine (1 mg lorazepam) was administered orally approximately 30 rnin before the start of treatment. ESWL was started in the combined ECG and respiratory triggered mode, but at certain moments the ECG triggering was discontinued. Shock wave electrical discharge ranged from 16 to 19 kV and the number of shock waves per kidney and per session ranged to 3000. Heart rate and arterial blood pressure were recorded at each blood sampling time. Holter monitoring (Oxford Medilog 4000-11 recorder) was initiated 30 rnin before lithotripsy and was continued for 30 rnin after the procedure. Venous blood sampling for plasma catecholamine assay by high performance liquid chromatography with electrochemical detection (Bauensfeld et al., 1984) was carried out at the following times: baseline control values 10 and 5 rnin before and at the start of ESWL (TO, T5, TlO), during the procedure after 10, 20, 30,40 and 50 rnin of shock wave applications (T20, T30, T40, T50 and T60) and thereafter 5, 10, 15 and 20 rnin (T65, T70, T75 and T80) after stopping treatment.
During the control baseline period all patients were positioned on the Lithostar table 10min before sampling in order to avoid sympathetic stimulation by stress apart from a possible ESWL-related catecholamine release by stimulation of the adrenal medulla.
Results Individual plasma catecholamine concentrations were recorded, including norepinephrine, epinephrine and dopamine (Tables 1, 2 and 3). The upper limits of normal reference values for the 3 catecholamines were : norepinephrine 300 ng/l, epinephrine 150ng/l and dopamine 100ng/l. The mean catecholamine profiles before, during and after ESWL are shown in Figure 1; no significant change in plasma levels of norepinephrine, epinephrine or dopamine was observed during or after the procedure in any of the 5 patients. Tables 4 and 5 reveal no significant changes in arterial blood pressure or heart rate (Figs 2 and 3). Holter monitoring revealed no cardiac arrhythmia with combined ECG and respiratory triggered shock wave release. When firing with only respiratory triggering, solitary ventricular extrasystoles occurred in 2 patients ; all were symptomatic and transient.
Discussion When compared with the baseline control values, no increase in the plasma concentrations of norepinephrine, epinephrine or dopamine was observed during or after lithotripsy. The mean baseline values of norepinephrine ranged between 370 and 470 ng/l before lithotripsy, which is slightly higher than the upper limit of the normal range : this may be related to the “non-basal” conditions due to emotional stress in the patients during the whole treatment period. However, it is interesting to note the absence of any increase during the procedure with repeated shock wave applications (Fig. 1). When carried out in the combined ECG and respiratory triggered mode, no increase in heart rate or blood pressure was found and no rhythmic disorder was noted in any patient. The absence of any significant increase in plasma catecholamine levels together with the lack of cardiac arrhythmia or extrasystoles, or changes in arterial pressure during combined respiratory and ECG triggered shock wave release, indicates that the influence of ESWL on cardiac activity reported by Chaussy and Schmiedt (1983) and Ector et al. (1989) may be related to direct cardiac excitation
20
BRITISH JOURNAL OF UROLOGY
Table 1 Individual Plasma Norepinephrine Levels (ng/l)
TO T5 T10 T20 T30 T40 T50 T60 T65 T70 T75 T80
Patient I (male, 62 years)
Patient (male. 61 years)
Patient 3 (female, 47 years)
Patient 4 (male, 57 years)
Patient 5 (male, 77 years)
Average
470 489 578 510 542 505 466 579 516 415 450 418
404 361 512 362 39 1 406 508 569 482 530 514 488
246 290 301 251 266 190 127 129 137 195 196 178
361 490 440 595 476 370 390 299 370 448 350 433
417 462 492 497 519 515 492 443 441 420 413 396
379.6 418 464 443 438.8 397.2 396.6 403.8 389.2 401.6 384.6 379.2
Patient 4 (male, 57 years)
Patient 5 (male, 77 years)
Average
SD
101 22 44 19 26 17 25 70 34 51 26 26
128 128 131 107 93 118 115 133 125 131 142 123
72.8 55.4 83.4 49.2 54.6 50.6 58.4 69.8 47.8 54.4 55.6 52.4
141.2
Patient 3 (female, 47 years)
Patient 4 (male, 57 years)
Patient 5 (male, 77 years)
Average
SD
< 25 < 25 < 25 < 25 < 25 < 25 < 25 < 25 < 25 < 25 < 25 < 25
< 25
< 25
25 25 25 25 25 25 25 25 25 51 25
< 25 < 25 < 25 < 25 < 25 < 25 < 25 < 25 < 25 95 < 25
32.2 42 37.8 25 36 30.6 39.2 44.8 36 37.8 44.2 37.4
f 16.0 f23.4
SD f 84.2 f 89.1
+ 103.9
7 135.9 f112.4
f 131.5 f 157.3 & 191
f151.1 f 124.3 & 121 f 137
Table 2 Individual Plasma Epinephrine Levels (ng/l) Patient I (male, 62 years)
TO T5 T10 T20 T30 T40 T50 T60 T65 T70 T75 T80
62 80 176 70 94 53 112 97 41 46 49 63
Patient 2 (male, 61 years)
47
< 25 48 24 35 25 < 25 < 25 < 25 < 25 41 25
Patient 3 (female, 47 years)
26 22 18 < 25 < 25 40 15 24 14 19 20 < 25
f47.5 f66.9 f38.4 + 35.7 40.1 f50 k47.0 f44.3
144.9 f49.6 f 42.7
Table 3 Individual Plasma Dopamine Levels (ng/l) Patient I (male, 62 years)
TO T5 TI0 T20 T30 T40 T50 T60 T65 T70 T75 T80
