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Print version ISSN 0034-7094
Rev. Bras. Anestesiol. vol.55 no.2 Campinas Mar./Apr. 2005
Anesthesia for transurethral resection of the prostate: comparison between two periods in a university hospital*
Anestesia para resección transuretral de próstata: comparación entre dos períodos en un hospital universitario
Liana Maria Torres de Araújo, TSA, M.D.I; Jyrson Guilherme Klamt, TSA, M.D.II; Luís Vicente Garcia, TSA, M.D.III
IAnestesiologista do Hospital das
Clínicas de Ribeirão Preto da FMRP USP
IIProfessor Assistente Doutor da Disciplina de Anestesiologia da FMRP USP. Co-responsável pelo CET/SBA do HC da FMRP USP
IIIProfessor Assistente Doutor da Disciplina de Anestesiologia da FMRP USP. Responsável pelo CET/SBA do Hospital das Clínicas da FMRP USP
BACKGROUND AND OBJECTIVES: Anesthesia
for transurethral resection of the prostate (TURP) has been studied for years
due to the uniqueness of the surgical procedure. This study aimed at comparing
TURP anesthetic techniques and possible surgical complications in two different
time periods with a ten-year interval, to detect evolution of those techniques
and decrease in morbidity-mortality rates.
METHODS: Medical records of all patients submitted to TURP in HC-FMRP-USP in two different 4-year periods were retrospectively evaluated: GI - surgical procedures (TURP) performed between 1989 and 1992; GII - surgical procedures (TURP) performed between 1999 and 2002. Malignant prostate and bladder neoplasias were excluded. A total of 300 medical records were included: 120 in GI and 180 in GII.
RESULTS: Regional anesthesia was predominant in both groups and spinal anesthesia was more frequently used. Mean procedure length was higher in GII and the incidence of intraoperative adverse events such as hypotension, arrhythmias and hypothermia was not statistically different between groups. In the first 24 postoperative hours however, more GI patients had acute myocardial infarction, probably due to lack of preoperative exams and cardiologic evaluation of patients submitted to surgery during this period. Length of stay in post-anesthetic care unit was similar between groups, but complications were more frequent in GI. Blood transfusions and perioperative mortality were not different between groups.
CONCLUSIONS: Although there was improvement in anesthetic techniques (new drugs and equipment) and in surgical apparatus after this 10-year interval, decrease in blood transfusions, surgical complications (intra or postoperative) or mortality rates could not be observed in the first 24 postoperative hours.
Key words: COMPLICATIONS, cardiac arrhythmias, hidric intoxication, hypotension; SURGERY, Urologic: TURP
JUSTIFICATIVA Y OBJETIVOS: La anestesia
para Resección Transuretral de Próstata (RTU) hace años, es objeto de diversos
estudios debido a las singularidades del procedimiento quirúrgico. Este estudio
tuvo la finalidad de comparar las técnicas anestésicas utilizadas y las posibles
intercorrencias peri-operatorias en dos períodos de tiempo distintos, con intervalo
de 10 años, visando detectar la evolución de la técnica anestésica y reducción
de la morbimortalidad en este tipo de procedimiento.
MÉTODO: De modo retrospectivo, fueron evaluados los prontuarios de todos los pacientes sometidos a la RTU de próstata en el HC-FMRP-USP en dos períodos distintos, de cuatro años: GI - resecciones transuretrales de próstata (RTU) realizadas entre los años de 1989 a 1992; GII - resecciones transuretrales de próstata (RTU) realizadas entre los años de 1999 a 2002. Fueron excluidos los pacientes portadores de neoplasias malignas de próstata o vejiga. Fueron analizados los prontuarios de 300 pacientes, siendo 120 en el GI y 180 en el GII.
RESULTADOS: Se observó que la anestesia regional predominó en ambos grupos, siendo la raquianestesia la más frecuentemente utilizada. La duración media del procedimiento fue mayor en el grupo II y la incidencia de eventos adversos en el período intra-operatorio, como hipotensión, disritmias cardíacas e hipotermia, no discrepó significativamente entre los grupos. Mientras, se observó mayor número de pacientes del grupo I con diagnóstico de infarto agudo del miocardio en las primeras 24 horas del período postoperatorio, probablemente atribuidos a la escasez de exámenes complementarios y de evaluación cardiológica previa en los pacientes sometidos a la cirugía en aquel período. El tiempo de permanencia de los pacientes en la sala de recuperación pos-anestésica fue semejante en los dos grupos, pero la incidencia de complicaciones fue mayor en el grupo I. El número de transfusiones sanguíneas y la mortalidad peri-operatoria no difirieron en los dos grupos.
CONCLUSIONES: Aunque, después de este intervalo de 10 años, haya habido mejora con relación al instrumental quirúrgico, a la monitorización anestésica y a la técnica anestésica (nuevas drogas y equipos), no se pudo observar reducción en el número de complicaciones (intra o postoperatorias), transfusiones sanguíneas o mortalidad en las primeras 24 horas después de la cirugía.
Transurethral resection of the prostate (TURP) is currently the most widely used surgical technique to treat benign prostatic hyperplasia (BPH), with approximately 350 thousand surgeries per year in the USA 1. From these, approximately 10% of patients will need a new surgery within 10 years 2.
TURP principle is to remove the adenomatous obstructive portion of the prostate through the urethra with the aid of a resectoscope and an electrocautery coupled to a lens system to improve visibility 3.
Among major TURP complications there are those related to anesthetic procedure (hypotension, hypertension, hypothermia, cardiac arrhythmias and mental confusion), those related to surgical procedure (TURP syndrome, bladder perforation, bacteremia and excessive bleeding) and others more directly related to patients' clinical conditions (acute myocardial infarction, stroke and intraoperative death). Spinal anesthesia is the most common technique for TURP, aiming at maintaining sensory level up to T9 to be able to early diagnose TURP syndrome via patients' symptoms.
General anesthesia is indicated when blockade is counterindicated, fails or is refused by the patient. No differences were observed in the incidence of complications between general and regional anesthesia 5. There are also cases of surgical resections under local anesthetic infiltration and sedation, with satisfactory results 6,7. However, this is an unusual anesthetic practice.
Anesthetic technique for TURP and other surgical procedures has greatly evolved. It is believed that there might be decrease in the incidence of anesthetic-surgical complications with the evolution of anesthetic techniques, new drugs and the increasing use of sophisticated monitoring, since monitoring informs changes in clinical status very early.
This study aimed at evaluating the anesthetic procedure for TURP in a University Hospital in two 4-year periods with a 10-year interval, and the incidence of perioperative complications in both periods, trying to correlate anesthetic technique advances to the decrease or not in complication rates.
Medical records of all patients submitted to TURP in the HC-FMRP-USP in two periods (1989-1992 (GI) and 1999-2002 (GII)) were retrospectively evaluated.
The following data were collected: general information (name, age, weight and surgery date), preoperative data (associated diseases, use of drugs, alcohol or cigarettes, autologous transfusion and previous ECG, chest X-rays and cardiologic evaluation), anesthetic and intraoperative data (anesthetic technique, blockade level, intraoperative hydration, anesthetic complications, irrigation fluid and surgery length) and postoperative data in the first 24 hours (PACU stay length, incidence of blood transfusion and mortality).
Malign prostate or bladder neoplasias were excluded. Statistical tests were Student's t and Chi-square tests.
From a total of 416 records, 72 patients with malign prostate or bladder neoplasias were excluded (32 in GI and 40 in GII), in addition to 44 patients whose records could not be located (32 in GI and 12 in GII). So, 300 records were evaluated (120 in GI and 180 in GII).
Demographics data are shown in table I. The only statistically significant difference was patients' weight.
Associated diseases are shown in table II. Systemic hypertension was the most prevalent in both groups. There has been a higher incidence of gout in GI and of stroke in GII.
More preoperative tests were asked to GII patients, with the exception of chest X-rays which were similar for both groups (Table III).
Regional anesthesia was the most common technique for both groups being general anesthesia the exception (Table IV). Among different regional techniques, spinal anesthesia was more frequently used for both groups. However, in comparing spinal anesthesia to other regional techniques, it has been significantly higher in GII. Only one GI patient received opioids associated to local anesthetics, while the association of opioids or clonidine to regional anesthesia was used in 60 GII patients (33.7%).
Regional anesthesia sensory level for most GI patients has remained below or equal to T9 while most GII patients had sensory levels above T9, although more than 25% of GII anesthetic records would lack this information (Table V).
Most GI patients have received more than 500 mL intravenous crystalloids for intraoperative maintenance and replacement, while in GII, more than half the patients have received 500 mL or less crystalloids (Table VI).
A considerable incidence of intraoperative adverse events were observed, being post regional anesthesia hypotension the most common event for both groups, followed by cardiac arrhythmias (Table VII).
Considering 45 minutes as optimal resection time 8, it has been observed in both groups a higher number of procedures lasting more than 45 minutes, being this difference significant for GII (Table VIII).
Mean PACU stay length was not different between groups and Aldrete-Kroulik scale was adopted as discharge criteria for all patients. There has been a higher incidence of PACU adverse events in GI, being pain and/or hypertension the most common events (Table IX).
Complications were not frequent for both groups. There has been higher incidence of bladder perforation and acute myocardial infarction in GI and higher incidence of false pathway and TURP syndrome in GII (Table X).
Most frequent irrigation fluid for GI was a mixture of distilled water (DW) and glycocoll. For GII, distilled water alone has been the most frequent fluid (Table XI).
Only one GI patient was re-operated (bladder perforation not identified in the intraoperative period). In GII, five patients were re-operated (urethral injury (1) and washing of vesical catheter obstructed by clots (4)).
Preoperative autologous transfusion was frequent in GI, being performed in more than 50% of patients, while homologous transfusion in absolute figures was similar for both groups (Table XII).
Mortality rate was 0.8% for GI (1 out of 120 patients) and 1.7% for GII (3 out of 180 patients) (Table XIII).
People submitted to TURP are in general elderly with associated diseases 8. Cardiac (24.9%) and pulmonary (14.5%) changes are the most common 1. So, to decrease complication rates, anesthetic technique should take into consideration co-morbidities of this population.
Smokers absorb more irrigation fluid when volumes above 1 liter are used 9, and drinkers have increased global risk both during and after surgery 10. Our study has observed that most TURP syndrome patients were smokers, and that drinkers had higher morbidity rates.
Intraoperative monitoring in GI was basically ECG with single precordial lead, which is a very simple equipment not analyzing ST segment and not available in all operating rooms. At the judgment of the anesthesiologist in charge, patients were also monitored with noninvasive blood pressure. During the 10-year interval, more modern equipment was acquired by the Anesthesiology Department so that GII monitoring consisted of ECG with 3 precordial leads, pulse oximetry and noninvasive blood pressure (manual until the year 2000, when monitors with automatic blood pressure reading, ECG and pulse oximetry - Model DIXTAL 2010® were acquired). The lack of ST segment evaluation and the lack of sensitivity and specificity to detect myocardial ischemia with the single lead ECG could be responsible for the non detection of intraoperative infarction or silent ischemia in GI patients.
Regional anesthesia was the most frequent technique for both groups. Spinal anesthesia is considered the technique of choice for TURP 11,12 because it allows better surgical conditions, decreases blood loss 13, decreases postoperative respiratory problems, prevents general anesthesia in the elderly and, in general, requires less anesthetic drugs.
Among major spinal anesthesia problems there are technical difficulties (especially in the elderly), longer time to reach adequate analgesia, blockade failure, higher risk of systemic hypotension, post-dural puncture headache and higher incidence of patients' refusal 11,12.
Due to irrigation fluid absorption through prostatic venous channels, which remain open during resection, it is recommended not to hydrate these patients too much. Most GI patients received more than 500 mL venous infusion. In GII, less than half the patients received more than 500 mL. Although considered a low volume, this could be adequate for the procedure since there is fluid load received through prostatic venous channels added to the difficulty of elderly patients to tolerate volume overload.
Most frequent cardiac arrhythmia was sinusal bradycardia promptly reverted with atropine.
Surgical length has gone beyond 45 minutes for most studied cases in both groups. This difference was significant for GII and was probably caused by surgical equipment. While in GI the lens system was coupled to the resectoscope slightly impairing visibility of the tissue to be resected (lens was on surgeons' hands and only them could see the tissue to be removed), in GII the lens system was integrated to a set of cameras helping prostate tissue visibility and allowing to show the images to trainning physicians, what probably resulted in longer resection time. These results differ from other studies 3,7, where surgical length is currently decreasing due to the adoption of shorter resections aiming at deobstructing the urethra and not totally removing the tumor. Longer surgical length for GII could be related to the higher incidence of TURP syndrome during this period.
All patients were discharged from PACU according to the same criteria (Aldrete-Kroulik scale) and length of stay was similar for both groups. There has been broad variation in discharge of these patients (110 to 1185 minutes for GI - mean 197.60; and 65 to 1205 minutes for GII - mean 229.30). The prevalence of adverse events (especially pain and/or hypertension) was higher for GI patients and this could be attributed to the lower incidence of opioids or clonidine associated to local anesthetics in GI. It is well known that these agents improve blockade quality and provide residual analgesia. The concern with pain control is increasing every day and this may contribute to a low incidence of PACU adverse events. Our study has not evaluated analgesic methods used in both periods.
Cardiac risk of prostate surgeries is considered intermediary (below 5%) by the American Society of Cardiology (combined incidence of death and non fatal acute myocardial infarction in non cardiac procedures) 14. There were 2 acute myocardial infarctions in the first 24 postoperative hours in GI. Both patients had no previous ECG, chest X-rays or cardiologic evaluation and presented good clinical evolution. The lack of better heart monitoring in GI might have been responsible for the failure in early detecting intraoperative ischemia.
The low incidence of surgical complications in both groups has made differences insignificant. Bladder perforation was more frequent in GI, probably due to precarious resectoscope; there has been higher incidence of TURP syndrome in GII (6 patients), with the death of 2 patients in the first 24 postoperative hours. Distilled water was used as single irrigation fluid in 4 out of these 6 patients.
Optimum irrigation fluid should be clear (to allow good surgical visibility), isotonic with regard to plasma, non-metabolized, non-toxic and non-hemolytic in case of absorption8. It should also be poorly ionized, rapidly excreted and cheap since large volumes are needed for the procedure 12. Most frequent solution currently used in the USA is 1% glycine although for some mannitol should be the best choice 15.
There has been higher incidence of re-operations in GI although without significant difference. Autologous blood transfusion was a frequent practice for GI the day before or the day of the surgery. The amount of removed blood was determined by the surgeon and varied from 400 to 500 mL; blood was collected by physicians of the Hematology Department HC-FMRP, stored in bags with CPD-A and returned to patients intraoperatively or in up to 24 postoperative hours. Such approach did not seem to be effective since a large number of GI patients was transfused as compared to GII (11 out of 120 GI patients were transfused (9.2%) as compared to 11 out of 180 GII patients (6.1%)). This may reflect more bleeding in GI (bleeding was not observed in our study) or more liberality of anesthesiologists in indicating transfusion for GI. It is worth highlighting that 2 GI patients (3.3%), even being submitted to autologous transfusion, had to receive homologous transfusion.
General TURP mortality is approximately 10%. Complications are directly related to adenoma size, resection time and surgical technique 1. Mortality rates found in both groups were higher as compared to the literature (0.2%) 1. The answer to this difference could be the place space in which the study was conducted - University Hospital with physicians being trained or specialized both in anesthesia and surgery. Higher GII mortality rate (in 50% of cases by TURP syndrome) could be partially attributed to the difference in surgical length and irrigation fluid between groups.
Notwithstanding improvements in surgical instrumentation, anesthetic monitoring and technique (new drugs and equipment), there has been no decrease in complications (intra or postoperative), in number of blood transfusions or mortality rate up to 24 postoperative hours in patients submitted to TURP in two different time periods.
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Dr. Luís Vicente Garcia
Address: Rua José da Silva, 624/94
ZIP: 14090-040 City: Ribeirão Preto, Brazil
Submitted for publication May 11, 2004
Accepted for publication December 17, 2004
* Received from Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo (HC FMRP USP), Ribeirão Preto, SP