[Anesthetic complications in a rehabilitation hospital: is the incidence related to the pre-anesthetic visit?]. / Complicação anestésica em hospital de reabilitação. A incidência tem relação com a consulta pré-anestésica?

INTRODUCTION: Approximately 234 million surgeries are done annually worldwide. There is a growing concern for the safety of the anesthetic act, and the pre-anesthetic consultation emerges as an important and widely recommended activity, used as a preventive measure for the emergence of a complication. OBJECTIVES: To describe the complications related to anesthesia, to identify the factors that contribute to its appearance and to reflect on ways to improve clinical practice. METHODS: 700 patients, 175 cases and 525 controls, were evaluated over a period of 21 months. The data obtained through the pre-anesthetic consultation were evaluated descriptively and then tested with conditional univariate and multivariate logistic regression analysis. RESULTS: 175 cases of anesthesia-related complications (2.74%) out of 6365 anesthetic acts were evaluated. Hypotension was the most common complication (40 patients, 22.8%), followed by vomiting (24 patients, 13.7%) and arrhythmia (24 patients, 13.7%). Among the complications, 55% were due to patient conditions, 26% accidental, 10% predictable and 9% iatrogenic. The complications were classified as mild in 106 (61%), moderate in 63 (36%) and severe in six (3%) patients. CONCLUSION: Patients with more impaired physical status (American Society of Anaesthesiology 3 and 4), with airway disease, tumor or parenchymal disease, diabetes or disorder of lipid metabolism, thyroid disease, former smokers and very prolonged anesthetic acts present a higher risk of anesthesia-related complications. Therefore, they should be actively investigated in the pre-anesthetic evaluation consultation.

Incidence of regional pain syndrome after carpal tunnel release. Is there a correlation with the anesthetic technique?

BACKGROUND AND OBJECTIVES: Complex regional pain syndrome (CRPS) previously known as reflex sympathetic dystrophy refers to a set of signs and symptoms that include pain, increased sweating, and vasomotor instability. Pain is usually triggered by a noxious stimulus in a peripheral nerve, which is disproportionate to the triggering stimulus. Its development after surgery is not uncommon varying with the type of intervention. An incidence of 2.1 to 5% has been reported after carpal tunnel release (CTR). Sympathetic blockade may prevent the onset of CRPS. However, there is no study validating this technique to prevent CRPS after CTR. The objective of the present study was to define the incidence of CRPS after CTR and its relationship with four anesthetic techniques. METHODS: Patients were randomly distributed to undergo one of the following techniques: general anesthesia, regional intravenous anesthesia with lidocaine, regional intravenous anesthesia with lidocaine and clonidine, or axillary plexus block. Postoperatively, they were followed-up by a nurse who was unaware of the anesthetic technique used, and follow-up was done through electronic patient records for up to 6 months after the anesthesia. During this period signs and symptoms typical of CRPS were investigated and, if positive, treatment was instituted. A descriptive evaluation using the chi-square test was performed. RESULTS: Three-hundred and one patients were investigated. Twenty-five of them developed CRPS, an incidence of 8.3%. Predominance was not observed among the anesthetic techniques used. Other factors such as smoking, profession, and other concomitant diseases were also investigated, and none showed a relationship with the development of post-CTR CRPS. CONCLUSIONS: Complex regional pain syndrome has an incidence of 8.3% after CTR surgery without association with the anesthetic techniques investigated.

Effect of isolated anticonvulsant drug use and associated to midazolam as pre-anesthetic medication on the Bispectral Index (BIS) in patients with cerebral palsy.

BACKGROUND AND OBJECTIVES: Patients with cerebral palsy (CP) frequently receive drugs for the treatment of concomitant diseases, such as seizures. Midazolam is a benzodiazepine with hypnotic action most often used as pre-anesthetic medication and its drug interactions in patients with CP are unknown. The objective of the present study was to evaluate the effect of midazolam as pre-anesthetic drug on the BIS of patients with CP undergoing chronic treatment with anticonvulsant agents. METHOD: Three groups of patients were assessed: CP without anticonvulsant treatment, CP undergoing treatment with anticonvulsant and a group with no disease and no medication use (control group). On the day before the surgery, with the patients conscious and in dorsal decubitus, the BIS monitor was placed and the basal BIS values were recorded. On the following day, 40 minutes before the surgery, the patients received 0.6 mg*kg(-1) of midazolam orally. Before the start of the anesthetic procedure, the same procedure for BIS recording was carried out after midazolam administration. RESULTS: A total of 107 patients were studied - 39 patients from the Control Group (CG) and 68 with a diagnosis of CP. Among these, 17 used anticonvulsant drugs. Regarding the mean BIS value after the midazolam administration, there was no difference between patients from the CG and those in the CP group that did not take anticonvulsant drugs, whereas the ones who took anticonvulsants exhibited a difference (p = 0.003). The possibility of decrease in the BIS after midazolam use increases according to the number of anticonvulsant drugs used by the patient. CONCLUSIONS: The chronic use of anticonvulsants associated to oral midazolam as pre-anesthetic medication can lead to the decrease in the BIS values, which configures deep level of hypnosis.

Influence of angiotensin-converting enzyme inhibitors on hypotension after anesthetic induction: is the preoperative discontinuation of this drug necessary?

BACKGROUND AND OBJECTIVES: The discontinuation of drugs such as angiotensin-converting enzyme inhibitors (ACE inhibitors) has been suggested based on reports of hypotension during anesthesia. This may imply on a higher risk of intraoperative hypertensive peaks with deleterious consequences for the patient. The objective of the present study was to evaluate the influence of the preoperative use of ACE inhibitors on the development of hypotension during anesthesia. METHODS: This is a case-controlled study of patients who developed hypotension after anesthetic induction. The control group was composed of patients of the same age and gender who underwent surgeries during the same period and who did not develop hypotension. Parameters of interest included: age, gender, size of the surgery, prior diagnosis of hypertension, use of ACE inhibitors, physical status (ASA), intraoperative bleeding, anesthetic technique, and duration of the surgery. RESULTS: In 2,179 surgeries, 40 patients developed hypotension. Twenty of those patients used ACEIs on the day of the surgery. The control group was composed by 171 patients, 11 of which used ACE inhibitors. Univariate analysis showed an association between hypertension and advanced age (p < 0.001), prior diagnosis of hypertension (p < 0.001), use of ACEIs (p = 0.006), physical status (ASA) (p = 0.006), and size of the surgery (p = 0.028). Stratified analysis did not show an association between hypotension and use of ACE inhibitors. On logistic regression, the association between the size of the surgery and the age of the patient and the development of hypotension remained. CONCLUSIONS: We did not observe an association between the use of ACE inhibitors and hypotension during anesthesia. The authors considered that the recommendation to discontinue ACE inhibitors on the day before the surgery should be reviewed. Other studies are necessary to confirm those results.

Oral midazolam as pre-anesthetic medication in children and teenagers with cerebral palsy. A comparative study on the variations of the bispectral index.

BACKGROUND AND OBJECTIVES: Midazolam is a benzodiazepine with hypnotic action widely used as pre-anesthetic medication in pediatric anesthesia. Children with cerebral palsy (CP) also benefit from the use of midazolam, but its effects on this group of patients, who present several particularities, including changes at the site of action of midazolam, are still unknown. The objective of this study was to evaluate the effects of midazolam, when used as pre-anesthetic medication, on the bispectral index (EEG-BIS) of patients with cerebral palsy. METHODS: Two groups of patients were evaluated: one group with the diagnosis of CP and the other without central and peripheral nervous system disorders. The EEG-BIS was recorded in the room, the day before the surgery and at the day of the surgery, 40 minutes after the administration of 0.6 mg.kg(-1) of oral midazolam. Patients with a history of paradoxal reaction to midazolam as well as patients in the control group who were using other medications were excluded. RESULTS: Seventy-seven patients of both genders, 4 to 18 years old, participated in this study. Differences in EEG-BIS between both groups were not detected. After the use of midazolam EEG-BIS decreased in both groups with a statistically significant difference in each group. Statistically significant intergroup differences were not observed. CONCLUSIONS: Midazolam, used as pre-anesthetic medication, at a dose of 0.6 mg.kg(-1), reduced basal EEG-BIS without characterizing hypnosis and without statistically significant differences between the study groups.

Thoracic epidural block performed safely in anesthetized patients. A study of a series of cases.

BACKGROUND AND OBJECTIVES: The development of paraplegia following the insertion of epidural catheter in anesthetized patients raised questions by some authors about the procedure, even without the confirmation that the lesion occurred because the patient was anesthetized. For this reason, we designed this study, with the objective to evaluate the frequency of neurological complications and development of sequelae after thoracic epidural block in patients under general anesthesia. METHODS: Patients undergoing thoracic surgeries from 02/16/2004 to 05/30/2006 participated in the study. After monitoring vital signs and the installation of general anesthesia, patients were placed in lateral decubitus for simple or continuous thoracic epidural block. Intercurrences, complications, and technical difficulties were recorded on a special form. Patients were followed postoperatively to detect the development of any signs and symptoms of neurological dysfunction. RESULTS: One hundred and thirteen patients were evaluated and the thoracic epidural catheter was placed in 108 patients. The puncture was considered traumatic, i.e., bleeding at the puncture site and multiple punctures, in 45 patients. Accidental perforation of the dura-mater occurred in two patients. In the immediate postoperative period, a patient complained of tingling in the lower limbs, another patient developed numbness in an upper limb, which resolved after the catheter was removed. Both patients had a single puncture. The other patients did not develop any signs or symptoms of neurologic changes. CONCLUSIONS: The cases studied here did not develop any neurologic complications. When performed judiciously and with specific care, thoracic epidural block can be safely done in the anesthetized patient.