An alternative for avoidance of general anaesthesia for infants when bilateral inguinal herniorrhaphy outlasts subarachnoid blockade.

Former premature infants represent a high risk surgical population. In order to minimize the risk of postoperative apnoea, subarachnoid blockade without sedation is known to be preferable to general anaesthesia for former premature infants undergoing bilateral inguinal herniorrhaphy. However, subarachnoid blockade affords only a limited duration of reliable anaesthesia. Nonroutine surgical delays and technical difficulties cannot always be anticipated by the anaesthesiologist. When bilateral inguinal herniorrhaphy outlasts the anticipated duration of subarachnoid blockade, the anaesthesiologist is confronted with a dilemma. Infants are unable to complain verbally, so the extent of subarachnoid blockade may be difficult to assess intraoperatively. Introduction of sedation or general anaesthesia under these circumstances increases the risk of postoperative apnoea, thereby defeating the purpose of the original choice of anaesthesia. Several alternatives have been proposed, but all involve disadvantages. In this report of two cases, a new solution to this clinical dilemma is presented.

A randomized comparison of the effects of continuous thoracic epidural analgesia and intravenous patient-controlled analgesia after posterior spinal fusion in adolescents.

BACKGROUND AND OBJECTIVES: Pain and gastrointestinal dysfunction are primary factors that delay recovery after posterior spinal fusion. Previous reports suggest that the choice of analgesic management may effect the course of recovery. This prospective, randomized study compared continuous thoracic epidural analgesia and patient-controlled analgesia in the postoperative care of adolescents undergoing posterior spinal fusion for idiopathic scoliosis. METHODS: Patients between 11 and 18 years of age were randomized to receive continuous thoracic epidural analgesia with bupivacaine-fentanyl (CEA, n = 17) or intravenous patient-controlled analgesia with morphine sulfate (n = 16). After surgery under general anesthesia, pain intensity was evaluated using a self-report visual analog scale (VAS). Postoperative time to resumption of bowel sounds, liquid intake, and side effects were also recorded. RESULTS: There were no significant differences between groups in VAS pain scores, side effects, or time to resumption of liquid intake. There was a significant difference (P = .0089) between groups in return of bowel sounds, which occurred earlier in patients receiving CEA. CONCLUSIONS: Continuous epidural analgesia and patient-controlled analgesia are comparably effective and safe after posterior spinal fusion. Return of bowel sounds occurred significantly more rapidly in patients receiving CEA postoperatively.

Pediatric pain management.

It is now recognized that from the newborn period onwards, children are capable of experiencing pain. This includes the premature infant. The challenge for healthcare providers is to incorporate methods of pain assessment and treatment into their daily practices. The child's understanding of pain closely follows the cognitive and behavioral model developed by Jean Piaget. Based on these developmental stages, pain assessment measures have been developed. Pharmacologic advances have accompanied this improved understanding of infant, child, and adolescent psychology. While acute pain accounts for the majority of children's experiences, recurrent/chronic pain states do occur (e.g. sickle cell related and neuropathic) and can be effectively treated.

Is nitrous oxide safe for bone marrow harvest?

Patients with non-Hodgkins lymphoma undergoing autologous bone marrow harvest were studied in a prospective, randomized fashion. All patients received a general anesthetic consisting of intravenous thiopental, fentanyl, and vecuronium and were ventilated with oxygen and isoflurane. Group I (19) patients also were ventilated with nitrous oxide (70%) whereas patients in Group II (19) did not receive nitrous oxide. Bone marrow samples were obtained at the beginning and end of the harvest. Viability of bone marrow mononuclear cells was assessed with a colony-forming unit-granulocyte macrophage (CFU-GM) assay, CFU-GM growth is a marker for myeloid progenitor cells and is dependent on intact deoxyribonucleic acid synthesis. Rate of neutrophil engraftment after autologous bone marrow transplantation was also studied. Both groups of patients were statistically similar in age, weight, anesthetic duration, CFU-GM counts at both sample draws, and the time for successful engraftment. There appears to be no difference in bone marrow viability as assayed by both CFU-GM colony growth and engraftment in human bone marrow exposed to a general anesthetic with nitrous oxide.

The effects of inhalation anesthetics on calcium-stimulated exocytosis in a natural membrane model system.

Sea urchin egg cortices were used as an in vitro natural membrane model system to determine the effects of inhalation anesthetics on the Ca2+-regulated exocytotic fusion of cortical vesicles with the egg plasma membrane. When Ca2+ was either absent or present in amounts below the threshold for exocytosis, methoxyflurane, halothane, enflurane, isoflurane, chloroform and fluoroxene, at concentrations up to 5 mM, had no effect on the fusion of cortical vesicles with the plasma membrane. However, when Ca2+ was present at or above threshold levels for exocytosis, each of the tested anesthetics caused an inhibition of cortical vesicle fusion. Exocytosis was inhibited most effectively by methoxyflurane (55%), followed by halothane (30%), while fluoroxene consistently had the least effect (less than 5%). These observations support the view that volatile anesthetics can impair the Ca2+-regulated fusogenic activities of natural membranes and are consistent with other data showing that inhalational agents inhibit secretory processes in intact cells.