Anesthetic management of labor and delivery in patients with elevated intracranial pressure

The anesthetic management of labor and delivery in patients with elevated intracranial pressure is complex. This review discusses the etiologies of diffuse and focal pathologies which lead to elevated intracranial pressure in pregnancy. The role of neuraxial and general anesthesia in the management of labor and delivery is also examined. Finally, a comprehensive review of strategies to minimize increases in intracranial pressure during general anesthesia for cesarean delivery is presented.

Changes in creatine phosphokinase (CK) concentrations after minor and major surgeries in children

BACKGROUND

During surgery, damage occurs to muscles in the area of the operation. The few studies that have examined creatine phosphokinase (CK) values after surgery have been in adults. The only study in children was after cardiac surgery. Understanding the normal enzyme pattern of change may help to differentiate malignant hyperthermia, anaesthesia-induced rhabdomyolysis and elevated CK values resulting from inherited muscle disease in cases in which these are suspected. The aim of this study was to delineate the normal rise of CK after minor and major surgery in children.

METHODS

A total of 71 patients aged 1 month-17 yr were studied. From the cohort of 71 patients, 46 underwent elective surgery (14 major, 32 minor) and in 25 the surgery was designated as an emergency surgery (21 major, 4 minor). The anaesthesia protocol was similar for both groups with halothane induction and isoflurane maintenance. Owing to its possible effect on CK, succinylcholine was avoided during the study.

RESULTS

The mean values of CK concentration before and after surgery were 63.1 iu litre(-1) and 151.5 iu litre(-1), respectively. The median CK elevation (range) for the major and minor surgery groups was 43 iu litre(-1) (4-647) and 10 iu litre(-1) (-28 to 122), respectively (P<0.0001).

CONCLUSIONS

CK concentrations in the major surgery group were significantly higher than the minor surgery group. This profile can contribute to the evaluation of patients who present with the possibility of malignant hyperthermia, anaesthesia-induced rhabdomyolysis and underlying muscle disease. Any rise of CK concentration above what is expected should prompt further investigation.

Postoperative outcome in high-risk infants undergoing herniorrhaphy: comparison between spinal and general anaesthesia

The incidence of inguinal hernia is higher in premature infants, particularly in low birth weight neonates. This latter group may also incur increased postoperative respiratory complications and inpatient admissions. The purpose of this study was to compare the effects of general and spinal anaesthesia on postoperative respiratory morbidity and on the length of hospital stay in high-risk infants undergoing inguinal herniorrhaphy. Forty patients, all high-risk infants who underwent unilateral or bilateral herniorrhaphies, were randomly assigned to receive general anaesthesia (n = 20) or spinal anaesthesia (n = 20). There was a significant difference in respiratory morbidity between the two groups, as well as a significant difference in the inpatient hospital stay. The present study suggests that spinal anaesthesia can be used safely for high-risk infants, preterm or formerly preterm, undergoing inguinal hernia repair.

Failure to control the airway in a patient with Hunter's syndrome

Hunter's syndrome is due to recessively inherited mucopolysaccharide storage diseases. The anaesthetic complications in this syndrome are related to the organs involved in the disease, but pertain especially to upper airway obstruction problems. We report a patient with Hunter's syndrome who, while under general anaesthesia for a simple procedure (the introduction of bilateral grommets), suffered a fatal outcome.

[Continuous quality improvement in anesthesia]

Slow continuous quality improvement (SCQI) in anesthesia is a process that allows identification of problems and their causes. Implementing measures to correct them and continuous monitoring to ensure that the problems have been eliminated are necessary. The basic assumption of CQI is that the employees of an organization are competent and working to the best of their abilities. If problems occur they are the consequences of inadequacies in the process rather that in the individual. The CQI program is a dynamic but gradual system that invokes a slower rate of response in comparison with other quality methods, like quality assurance. Spectacular results following a system change are not to be expected an the ideal is slow and continuous improvement. A SCQI program was adapted by our department in May 1994, according to the recommendations of the American Society of Anesthesiologists. Problem identification was based on 65 clinical indicators, reflecting negative events related to anesthesia. Data were collected using a specially designed computer database. 4 events were identified as crossing previously established thresholds (hypertension, hypotension, hypoxia and inadequate nerve block). Statistical process control was used to establish stability of the system and whether negative events were influenced only by the common causes. The causes responsible for these negative events were identified using specific SCQI tools, such as control-charts, cause-effect diagrams and Pareto diagrams. Hypertension and inadequate nerve block were successfully managed. The implementation of corrective measures for the other events that cross the threshold is still in evolution. This program requires considerable dedication on the part of the staff, and it is hoped that it will improve our clinical performance.

Rapid cytological diagnosis of primary skin tumours and tumour-like conditions

This study presents the results of fine needle aspiration cytology performed on 1,263 skin lesions which were clinically suspicious for neoplasia. The purpose of the study was to investigate the accuracy of fine needle aspiration cytology for the diagnosis of skin tumours and to assess its clinical value. Twenty-one to 27 Gauge needles were used and the specimens were stained by a quick Giemsa stain. The cytological examination reported 826 primary malignant tumours and 437 benign lesions. Five hundred and thirteen of the cytologically malignant cases and 123 of the benign ones had a subsequent histological examination. The correlation between cytology and histology revealed 6 false positive cytological results and one false negative. Persuaded by our results, we believe that fine needle aspiration cytology can give highly reliable information concerning the histological type or primary skin tumours. It can also detect or exclude relapses of previously treated neoplasms. The procedure is non-traumatic, safe, quick, inexpensive and very well tolerated by the patients.

Plasmapheresis in neuroleptic malignant syndrome

Neuroleptic malignant syndrome is a severe and potentially fatal reaction to neuroleptic drugs. Treatment requires withdrawal of the neuroleptic agent, metabolic and cardiovascular support, physical cooling and treatment with dantrolene sodium and bromcriptine mesylate. We report a therapeutic success of plasmapheresis in a case of neuroleptic malignant syndrome in which conventional therapy had failed. We postulate that plasmapheresis may prove to be a useful tool in treating this frequently fatal disease.

Effects of peritonsillar infiltration on post-tonsillectomy pain. A double-blind study

The concept that local infiltration of the operative area with a local anesthetic when using general anesthesia could alleviate postoperative pain is well known. We tested this concept on 129 patients scheduled for elective tonsillectomy. The patients were investigated in a double-blind, randomized study, and the operation was carried out via the standard technique of infiltrating the peritonsillar area preoperatively. The results indicated that preincisional infiltration of the tonsils with bupivacaine hydrochloride markedly decreased the intensity of pain following tonsillectomy, well beyond the immediate postoperative period.

Spinal bupivacaine in ambulatory surgery: the effect of saline dilution

The safety of lidocaine spinal anesthesia has recently been called into question by reports of both permanent and transient neurologic toxicity. This study explored the possibility of adapting the longer acting spinal bupivacaine to ambulatory surgery. Sixty patients presenting for ambulatory arthroscopy were randomized to four groups receiving the following spinal anesthetics: Group I (15 mg bupivacaine), 3 mL of 0.5% spinal bupivacaine in 8% dextrose; Group II (10 mg bupivacaine), 2 mL of the 0.5% spinal bupivacaine+1 mL saline; Group III (7.5 mg bupivacaine), 1.5 mL of the 0.5% spinal bupivacaine%1.5 mL saline; Group IV (5 mg bupivacaine), 1 mL of the 0.5% spinal bupivacaine+2 mL saline. Maximum block height was T-5 in Group I versus T-8 in the other groups. Onset times to peak block were similar in all groups and averaged 14 min. Time to two-segment regression, complete regression, micturition, and discharge were significantly reduced from Group I to Group II and from Group II to Group III. Reductions in times between Groups III and IV did not achieve statistical significance. Times from placement of the spinal block until discharge were 471 +/- 35, 260 +/- 15,202 +/- 14, and 181 +/- 8 min, respectively, for the four groups. The intensity of motor block decreased significantly from group to group, such that 13 of the 15 patients in Group IV failed to achieve Bromage level 2 or 3. The intensity of sensory block also decreased from group to group with four patients in Group IV having pain intraoperatively that required further treatment. Therefore, Group III provided the optimum combination of adequate depth of anesthesia and rapid recovery. The results of this study indicate that spinal anesthesia with 7.5 mg of 0.5% bupivacaine in 8% dextrose diluted with an equal volume of saline provides an acceptable spinal anesthetic for ambulatory arthroscopy with a recovery profile appropriate to the ambulatory setting.

Sublingual buprenorphine compared to morphine delivered by a patient-controlled analgesia system as postoperative analgesia after prostatectomy

After open prostatectomy, 52 patients were randomly allocated to two treatment groups. Group A (26 patients) received buprenorphine sublingually, and in group B (26 patients) the analgesia was induced using a patient-controlled analgesia system with morphine. The total dose of morphine given during the first 24 h was 72 +/- 8 mg compared to 1.6 +/- 0.45 mg of buprenorphine. The total dose of buprenorphine on days 2 and 3 was significantly lower than the total dose of morphine (p < 0.01). There were no significant differences in visual pain scores, side effects, mean arterial blood pressure, pulse rate and respiration rate between the two groups. Sublingual application of buprenorphine offers an effective and easy alternative to the parenteral route of morphine for the management of postoperative pain.

The influence of high spinal anesthesia on sensitivity to midazolam sedation

We tested whether a high spinal anesthesia may alter the susceptibility to the soporific effects of sedatives. Twenty ASA grade I and II women undergoing elective abdominal hysterectomy were randomly allocated into two groups. Patients in Group I were given a subarachnoid injection of 12 mg hyperbaric tetracaine and those patients who after 10 min had a sensory level of T4-6 (10 patients) were included in the study. Ten additional patients (Group II) received no spinal injection. Induction of anesthesia was performed on all patients by injecting 1 mg of midazolam intravenously every 30 s until the patient failed to respond to three repeated commands to squeeze the anesthetist's hand. This was considered the induction dose or end-point for the purposes of the study. Patients were then given a neuromuscular blocker, ventilated with oxygen, nitrous oxide, and a volatile anesthetic, tracheally intubated, and maintained under general anesthesia for the remainder of the operation. The dose of midazolam administered to the point of patient failure to respond to command was 7.6 +/- 0.72 mg SEM for Group I and 14.7 +/- 1.16 mg SEM for Group II, (P < 0.0001). These results support the conclusion that patients having a high spinal anesthetic are more sensitive to the sedative effects of midazolam.

Awareness detection during caesarean section under general anaesthesia using EEG spectrum analysis

This study examined the relationship between the EEG (spectral edge frequency 90-SEF90) and the occurrence of awareness defined for the purpose of this study as responsiveness to verbal commands. Fifty women undergoing general anaesthesia for elective Caesarean section were examined. Responsiveness to verbal commands was detected every minute in the period from the induction of anaesthesia to the delivery of the newborn using the Tunstall isolated forearm technique and correlated with the SEF90 value. The patients were assigned by a randomized code to receive either thiopentone (4 mg.kg-1) or ketamine (1 mg.kg-1) for induction of anaesthesia. Before the administration of succinylcholine a tourniquet was applied to the free arm, and inflated to 200 mmHg, to maintain motor function to one arm. The EEG recordings started five minutes before induction and were recorded throughout anaesthesia. The incidence of responsiveness to verbal commands was lower in the ketamine group (24%) where the average SEF90 was 12.0 +/- 3 Hz, than in the thiopentone group (52%), where the average SEF90 was 18.09 +/- 3 Hz (P = 0.01). The results suggest that SEF values of < or = 8.6 Hz were sufficient to avoid responsiveness to verbal commands.

The influence of patient positioning on the hemodynamic changes in TURP patients with severe coronary disease

Hemodynamic changes were studied in 10 patients with severe coronary disease during routine transurethral prostatectomy (TURP) when performed in the lithotomy position with and without elevation of the legs. The patients undergoing the procedure in the lithotomy position with elevation of the legs exhibited significant hemodynamic changes as compared with those undergoing the procedure without elevation of the legs. This leads us to conclude that performing TURP in the lithotomy position without elevation of the legs benefited the patient by stabilizing hemodynamic factors.