Alterations in exogenous substrate metabolism in sepsis.

Metabolic rates and substrate utilization patterns were evaluated by using a rate cecal ligation and perforation model. Animals that survived for 48 hours after the induction of sepsis were hypermetabolic and responded appropriately to varying exogenous substrate infusions. In contrast, animals that did not survive to 48 hours were premorbidly hypometabolic and failed to adjust their oxidation patterns in response to the exogenous substrate supply. These findings suggest the benefit of individually tailoring the supply of exogenous nutrients in critically ill patients with sepsis and of frequent reassessment of metabolic parameters, including the resting energy expenditure and respiratory quotient.

The sternalis muscle: a normal finding encountered during breast surgery.

We report a case of mastectomy and immediate reconstruction in which the sternalis muscle, a normal anatomic variant, was encountered. Most surgeons we surveyed are not familiar with this variant.

Intravenous bumetanide attenuates the rise in plasma vasopressin concentrations during major surgical operations.

During a study in seven patients on the endocrine response to major surgical procedures under general anaesthesia an incidental finding was that the administration of intravenous bumetanide prior to surgical stimulation led to reduced concentrations of plasma vasopressin (AVP) when compared with a control group of patients.

Comparison of the reinforced laryngeal mask airway and tracheal intubation for adenotonsillectomy.

One-hundred and four patients were allocated randomly to receive anaesthesia for adenotonsillectomy via either a reinforced laryngeal mask airway or tracheal tube. Airway maintenance and protection were assessed during and after operation. The reinforced laryngeal mask did not interfere with surgical access; it resisted compression and protected the lower airway from contamination with blood. Four patients were withdrawn from the laryngeal mask airway group: two because difficulty with placement, and two because the laryngeal mask was obstructed distally when the Boyle Davis gag was opened fully. In children, recovery was less eventful in the laryngeal mask airway group, with less airway obstruction (P < 0.001) and better airway acceptance (P < 0.05). The reinforced laryngeal mask airway provided a clear, secure airway until recovery of protective reflexes.

Review of uses of the laryngeal mask in ENT anaesthesia.

A review of the various uses of the laryngeal mask in otorhinolaryngological surgery is presented. Its primary use is in airway management, especially during recovery from anaesthesia.

Caudal analgesia for perianal surgery. A comparison between bupivacaine and diamorphine.

Seventy-three patients undergoing elective perianal surgery were randomly divided into a control group, a group who received a caudal injection of 20 ml bupivacaine 0.5% plain and a group who received diamorphine 2.5 mg in 10 ml normal saline by caudal injection; a comparison was then made of postoperative analgesia requirements. The bupivacaine group had better analgesia than the control group for the first 8 hours, after which there was no difference. The diamorphine group had better analgesia than the control group for the first 24 hours postoperatively. Side effects were less in the diamorphine group than the control, or the bupivacaine group. In particular, 41% of the bupivacaine group complained of some degree of urinary retention and one patient required temporary catheterisation. It is concluded that caudal diamorphine gives good postoperative analgesia for perianal operations, particularly when motor blockade is not wanted by the surgeon.

Comparison of the reinforced laryngeal mask airway and tracheal intubation for nasal surgery.

Airway maintenance and protection during anaesthesia and recovery provided by the reinforced laryngeal mask airway was compared with the sequential use of a tracheal tube followed by the Guedel airway in 66 patients having anaesthesia for nasal surgery. One patient was withdrawn from the laryngeal mask group because the airway was difficult to position. All patients had an oropharyngeal pack inserted and Moffett's solution instilled into the nasal cavities. At the end of surgery the nasal cavities were packed. During operation airway maintenance was good and airway protection was equally effective in both groups. Contamination of the lower airway occurred in only five patients. During recovery from anaesthesia the laryngeal mask and Guedel airway were well tolerated by most patients, but only the mask laryngeal provided an unobstructed airway in all patients. The laryngeal mask protects the larynx from contamination during and after operation until the return of the patient's own protective reflexes.

Efficacy and safety of the laryngeal mask airway vs Guedel airway following tracheal extubation.

PURPOSE: To compare the safety and efficacy of the laryngeal mask airway (LMA) with the Guedel airway during the recovery period. METHODS: In a prospective randomised trial in the Post Anesthesia Care Unit (PACU), 52 patients (ASA 1 and 2) were randomised to receive either a laryngeal mask airway (LMA: n = 26) or a Guedel airway (n = 26) during the recovery period after middle ear surgery. Ease of airway maintenance was graded and the presence of coughing was noted. Peripheral arterial oxygen saturation (SpO2) was measured continuously by pulse oximetry in the PACU. Readings were taken on arrival (time 0) and for five minutes afterwards. RESULTS: There was no difference in sex, age, weight or incidence of smoking between the two groups. In the LMA group 25 patients required no airway manipulation and only one patient required repositioning of the LMA. In the Guedel group severe difficulty maintaining the airway was experienced in two patients, moderate difficulty in five patients and mild difficulty in 12 patients. Seven patients required no airway manipulation. The LMA group showed higher ease of airway maintenance scores, (P = < 0.0001) and less coughing (P = 0.0496). At time 0 and at one minute the LMA group had higher median SpO2 (97% and 97%) than the Guedel group (95% and 96%), (P = 0.0002 and 0.0362). There was no further difference in SpO2. CONCLUSIONS: The LMA provides easier airway maintenance, less coughing and initially higher median SpO2 when compared with the Guedel airway in the recovery period.

A quantitative evaluation of stress associated with indwelling superior vena cava cannulae in rats.

"Nonrestraining" superior vena cava (SVC) cannulae are commonly used in rat metabolic studies. The objective of this study was to evaluate the level of stress and metabolic alterations associated with surgical placement and subsequent maintenance and use of an indwelling intravenous cannula as measured by resting energy expenditure (REE), respiratory quotient (RQ), urinary nitrogen excretion, and substrate utilization pattern. Nine rats underwent SVC cannulation and six rats underwent sham operation. Postoperatively, animals were starved for 48 hr and then refed either parenterally or orally for 48 hr. Sham-operated animals adapted appropriately to starvation within 24 hr by decreasing REE 14% and increasing utilization of fat (RQ:0.89----0.78). Hypometabolic adaptation to starvation was delayed in cannulated animals until the second postoperative day, but appropriate alterations in energy substrate utilization were not affected by the presence of cannulae. Cannulae did not affect the metabolic response to oral refeeding with similar increases in REE and similar patterns of substrate utilization in sham-operated and cannulated animals. Animals refed parenterally demonstrated higher REE and apparent fat deposition (RQ greater than 1) consistent with continuous hypercaloric glucose administration. Urinary nitrogen excretion was not affected by the presence of cannulae. Cannula-associated metabolic alterations are minimal and transient and do not preclude detection and quantification of alterations associated with composition or utilization of exogenous substrates.

Effect of propranolol on nitrogen and energy metabolism in sepsis.

Pharmacologic therapy designed to block adrenergic activity or alter hormonal milieu may modulate energy and protein metabolism in stress. The metabolic effects of propranolol (beta adrenergic receptor blocker) in sepsis was investigated in 22 well-nourished rats that underwent superior vena caval cannulation, cecal ligation, and puncture. Animals were randomly assigned to receive either a continuous infusion of 0.7 mg/day of propranolol combined with parenteral nutrition (n = 11) or parenteral nutrition alone (n = 11). Both groups received isocaloric, isonitrogenous, isovolemic, parenteral nutrition post-operatively for 24 hr. Nitrogen balance was better for the propranolol group than for the control group (+743 +/- 84 mg/kg/day versus +300 +/- 63 mg/kg/day, respectively, P less than 0.05). A significant difference between the pharmacologic therapy and control groups was noted for urinary 3-methylhistidine excretion versus control (0.99 +/- 0.08 micrograms/kg/day versus 7.5 +/- 0.37 micrograms/kg/day, respectively, P less than 0.01). Measured energy expenditure was similar for both pharmacologic therapy and control groups (149 +/- 20 kcal/kg/day versus 134 +/- 11 kcal/kg/day, respectively, P = N.S.). No statistically significant difference was demonstrated for 24-hr survival between propranolol and control groups (73 and 64%, respectively). Continuous, low-dose propranolol promotes nitrogen retention and decreases 3-methylhistidine excretion without altering energy expenditure in parenterally fed septic rats.