Parenteral amino acids v. dextrose infusion: an anabolic strategy to minimise the catabolic response to surgery while maintaining normoglycaemia in diabetes mellitus type 2 patients.

Loss of body protein and hyperglycaemia represent typical features of the stress response to surgery and anaesthesia. This appears to be particularly pronounced in patients with diabetes mellitus type 2. The aim of the present study was to highlight the greater benefit of amino acids (AA) as represented by positive protein balance and maintenance of blood glucose homoeostasis compared with dextrose (DEX) in diabetic patients after colorectal surgery. A total of thirteen patients underwent a 5 h stable isotope infusion study (2 h fasted, 3 h fed with an infusion of AA (n 6) or DEX (n 7)) on the second post-operative day. Glucose and protein kinetics were assessed by using the stable isotopes l-[1-¹³C]leucine and [6,6-²H2]glucose. The transition from fasted to fed state decreased endogenous glucose production (P < 0·001) in both groups, with a more profound effect in the DEX group (P = 0·031). In contrast, total glucose production was increased by the provision of DEX while being lowered by AA (P = 0·021). Feeding decreased protein oxidation (P = 0·009) and protein synthesis in the AA group, whereas DEX infusion did not affect oxidation and even decreased protein synthesis. Therefore, only AA shifted protein balance to a positive value, while patients in the DEX group remained in a catabolic state (P < 0·001). Parenteral nutritional support with AA rather than with DEX is an effective strategy to achieve a positive protein balance while maintaining normoglycaemia in diabetic patients after colorectal surgery.

Postoperative patient complaints: a prospective interview study of 12,276 patients.

STUDY OBJECTIVE: To evaluate the incidence of perioperative minor adverse events and to analyze patient satisfaction based on potential explanatory variables. DESIGN: Structured, face-to-face interview of 25% of all patients undergoing surgery during the period from January 2003 through June 2006. SETTING: Academic university medical center. PATIENTS: 12,276 patients (5,793 men and 6,483 women) from all surgical disciplines: 7,440 patients had general anesthesia, 4,236 patients had regional anesthesia, and 600 patients had a combined general-regional anesthetic technique. MEASUREMENTS: Occurrence of perioperative minor adverse events was assessed during the interview. Patient satisfaction was measured with a 4-point Likert scale. MAIN RESULTS: 3,652 (30%) patients reported at least one perioperative complaint and 737 (6%) patients reported multiple minor adverse events. Overall, a total of 4,475 minor adverse events were reported. Leading adverse events included postoperative nausea and vomiting (1,705 complaints), sore throat (1,228 complaints), and hoarseness (802 complaints). Patient satisfaction with anesthetic care was generally high (97% satisfied or highly satisfied). Patients were significantly more satisfied following regional than general anesthesia (P < 0.001). Patient dissatisfaction was also associated with the occurrence of at least one minor adverse event (P < 0.001) or with increasing ASA physical status (P < 0.001). CONCLUSION: Minor events occur with a surprisingly high incidence and are significantly associated with patient dissatisfaction. Regional anesthesia is associated with fewer patient complaints and significantly higher postoperative patient satisfaction.

B-type natriuretic peptide in patients undergoing orthopaedic surgery: a prospective cohort study.

BACKGROUND AND OBJECTIVE: Postoperative cardiac complications pose a substantial risk to patients undergoing orthopaedic surgery. METHODS: B-type natriuretic peptide (BNP) was determined preoperatively in 270 patients undergoing scheduled orthopaedic surgery. The accuracy of BNP to predict the occurrence of in-hospital cardiac events was evaluated as the primary endpoint. Cardiac events at 1 year of follow-up were considered secondary endpoints. RESULTS: Preoperative BNP levels were significantly higher in the four patients experiencing in-hospital cardiac events than in patients without events [median 306 pg ml(-1) (range 123-3958) vs. 35 pg ml(-1) (range 14-2074), P = 0.01]. In a receiver operating characteristic analysis for the prediction of in-hospital cardiac events, the area under the receiver operating characteristic curve for BNP was 0.86 (95% confidence interval 0.74-0.99). The optimal predictive accuracy was achieved with a BNP threshold of 174 pg ml(-1). Importantly, the combination of BNP and the American Society of Anesthesiologists score further improved this accuracy. Additionally, BNP retained a high predictive accuracy in the subgroup of patients with known cardiac diseases [area under the receiver operating characteristic curve 0.85 (95% confidence interval from 0.65 to <1)]. The area under the receiver operating characteristic curve for the prediction of long-term cardiac events by BNP was 0.71 (95% confidence interval 0.57-0.84). CONCLUSION: In patients undergoing orthopaedic surgery, preoperative BNP levels can predict short-term and long-term postoperative cardiac events. Despite the paucity of endpoint events observed in this study, our results are in agreement with all prior investigations. BNP used in addition to an American College of Cardiology/American Heart Association guideline-based risk assessment might, therefore, be a useful tool in the preoperative evaluation of patients undergoing orthopaedic surgery.

Patient satisfaction with continued versus divided anesthetic care.

STUDY OBJECTIVE: To evaluate patient acceptability of continued versus divided anesthetic care. DESIGN: Patient satisfaction ratings with continuous and divided anesthetic care were assessed by patient questionnaire. In addition, the effect of training anesthesia personnel in communication regarding divided anesthesia care was examined. SETTING: University medical center. PATIENTS: 654 consecutive patients scheduled for elective surgery. MEASUREMENTS AND MAIN RESULTS: Overall postoperative patient satisfaction was high and not different between patients experiencing continued or divided anesthetic care (P=0.97). Asking patients before their operations about the importance of continued anesthetic care resulted in a highly significant difference between the two groups. In the continued anesthetic care model, patients felt it more important to experience continued care. In contrast, patients who were told that another anesthesiologist would take care of them rated the same question with a lower importance (P<0.001). CONCLUSION: Before their operations, more than half of the patients felt it very important that they were visited and anesthetized by the same physician. Nevertheless, postoperative patient satisfaction was equally high regardless of whether they were anesthetized by the same physician who had visited them preoperatively.

Sevoflurane decreases bispectral index values more than does halothane at equal MAC multiples.

At the minimum alveolar concentration (MAC) of inhaled anesthetics, 50% of subjects move in response to noxious stimulation. Similarly, at MAC-awake, 50% of subjects respond appropriately to command. The bispectral index (BIS) nominally measures the effect of anesthetics on wakefulness or consciousness. We postulated that the use of halothane with a larger MAC-awake/MAC ratio than sevoflurane would produce higher BIS values at comparable levels of MAC. We studied 33 unpremedicated patients anesthetized by inhalation, 18 with sevoflurane and 15 with halothane. We measured BIS before and during anesthesia at 1 MAC, both before and after tracheal intubation facilitated by fentanyl and rocuronium and then at 1.5 MAC. BIS measurements were made after meeting steady-state conditions. No surgery was performed during this study. BIS values in awake patients did not differ between the sevoflurane and halothane groups (96 +/- 2 and 96 +/- 2, mean +/- sd, respectively). At 1 MAC without and with neuromuscular blockade and at 1.5 MAC, BIS values for patients anesthetized with halothane (54 +/- 7, 56 +/- 7, and 49 +/- 7, respectively) exceeded those for patients anesthetized with sevoflurane (34 +/- 6, 34 +/- 6, and 29 +/- 5, respectively) (P < 0.0001). This finding adds to other evidence indicating that BIS is drug specific.

Small-dose intrathecal clonidine and isobaric bupivacaine for orthopedic surgery: a dose-response study.

We examined the dose-response relationship of intrathecal clonidine at small doses (

The differential effect of halothane and 1,2-dichlorohexafluorocyclobutane on in vitro muscle contractures of patients susceptible to malignant hyperthermia.

UNLABELLED: Malignant hyperthermia (MH) is an autosomal dominant, potentially fatal pharmacogenetic disorder of skeletal muscle. Approximately half of all known MH families show a linkage to the ryanodine receptor type 1 (RY1) gene. Although our knowledge of the diagnosis, genetics, and therapy of MH has improved, the exact pathogenesis and the role of volatile anesthetics as trigger substances for an MH crisis remain unknown. Compounds that do not obey the Meyer-Overton hypothesis (i.e., nonimmobilizers) are today an important part of research on anesthetic mechanisms. We designed this study to test the hypothesis that the nonimmobilizer 1,2-dichlorohexafluorocyclobutane (2N) compared with halothane has different effects on in vitro muscle contractures of muscle bundles from MH-susceptible (MHS) individuals. In vitro muscle contracture tests were performed with either halothane (approximately 660 microM, equivalent to approximately 4 minimum alveolar anesthetic concentration [MAC]) or 2N ( approximately 100 microM, equivalent to approximately 5 times predicted MAC). MAC is defined as the anesthetic concentration that prevents nocifensive movements after a surgical stimulus in 50% of subjects. In contrast to halothane, 2N caused only minimal muscle contractures in muscle bundles from six MHS patients (0.13 g [0.04-0.31 g] vs 1.95 g [1.60-4.70 g], median values and ranges; P = 0.004). Halothane and 2N differ in their effects on muscle contractures of MHS individuals, possibly because of a differing action on MH RY1. IMPLICATIONS: Using in vitro contracture tests, we showed that halothane and the nonimmobilizer 1,2-dichlorohexafluorocyclobutane differ in their effects on contractures of muscle bundles from individuals susceptible to malignant hyperthermia (MH) as a result of their differing action on MH ryanodine receptors. These findings render this receptor a possible molecular target for volatile anesthetic action.