Infection rate among nutritional therapies for acute pancreatitis: A systematic review with network meta-analysis of randomized controlled trials.

BACKGROUND: Infection in acute pancreatitis (AP) is associated with nutritional therapies including naso-gastric (NG), naso-jejunal (NJ), and total parenteral nutrition (TPN). To examine infections among NG, NJ, TPN, and no nutritional support (NNS) in treating patients with AP. METHODS: The investigators completed comprehensive search in the Cochrane library, EMBASE, PubMed, Web of Science, and ClinicalTrials.gov without restriction on language and publication date before January 21, 2019. They also searched the reference lists of relevant studies for randomized controlled trials (RCTs) comparing NG, NJ, TPN, and NNS among patients with AP. Quantitative synthesis was conducted in a contrast-based network meta-analysis. To clarify effects, a network meta-analysis was conducted to calculate the surface under the cumulative ranking curve (SUCRA). Beside of overall infections, the event rates of infected pancreatic necrosis, bacteremia, line infection, pneumonia, urinary tract infection, and other types of infections were measured. RESULTS: The network meta-analysis of 16 RCTs showed that NJ had significantly lower overall infection rates compared with TPN (risk ratio: 0.59; 95% confidence interval: 0.38, 0.90); and NG had a larger effect size and higher rank probability compared with NJ, TPN, and NNS (mean rank = 1.7; SUCRA = 75.8). TPN was the least preferred (mean rank = 3.2; SUCRA = 26.6). CONCLUSIONS: NG and NJ may be preferred therapies for treating patients with AP. Clinicians may consider NG as a first-line treatment for patients with AP (including severe AP) and even in patients receiving prophylactic antibiotics. In addition, we found that NNS should be avoided when treating patients with severe AP.

Bloodless and non-inotropic cardiac surgery under closed-circuit anesthesia.

BACKGROUND: The safety of homologous blood transfusion has become a major concern for patients and physicians. Current transfusion practice is highly variable and may be associated with inappropriate blood use. Inotropic agents have been almost routinely administered perioperatively to patients undergoing cardiac surgery to overcome low cardiac output due to cardiopulmonary bypass (CPB) and cardioplegia-induced cardiac ischemic arrest. In this study, we evaluated the feasibility of bloodless and non-inotropic open-heart surgery. METHODS: Perioperative clinical data were retrospectively collected from two groups of patients undergoing open-heart surgery by one surgeon in the same season. Twenty consecutive patients underwent a bloodless approach and received isoflurane-based closed-circuit general anesthesia and 20 consecutive patients (comparison group) underwent fentanyl-based anesthesia. A cell-saver was used for all patients to collect the CPB circuit blood for retransfusion. In the comparison group, conventional criteria were applied for blood transfusion and inotropic support and the goal was to keep hemoglobin > 10 g/dL and cardiac index > 2.2 L/min/m(2). In the bloodless group, new criteria for blood transfusion and inotropic support were used and included (1) low cardiac output syndrome, (2) impaired hemodynamic status and mixed venous oxygen saturation, (3) inadequate urine output, (4) metabolic acidosis, (5) ischemic signs on electrocardiography, and (6) patient's autonomy after being informed of and discussing the benefits and risks of blood transfusion. RESULTS: In both groups, there was no in-hospital mortality and all patients were discharged in a stable condition. Eighteen of 20 (90%) patients did not receive blood transfusion, while inotropic support was not provided in 17 of 20 (85%) patients in the bloodless group; in contrast, blood transfusion and inotropic support were required for all patients in the comparison group (both: p<0.01). All patients in the bloodless group, except one with severe chronic obstructive pulmonary disease (1-second forced expiratory volume of 0.9 L), accomplished earlier extubation (mean+/-standard deviation, 1.2+/-1.1 hours) and shorter intensive care unit stay (3.1+/-2.1 days), as compared with patients in the comparison group (19.5+/-2.5 hours and 5.1+/-1.7 days, respectively; both: p<0.01). Systemic vascular resistance was significantly lower in the bloodless group. CONCLUSION: In conclusion, bloodless and non-inotropic cardiac surgery is feasible with the aid of a cell-saver and closed-circuit anesthesia in combination with new practice guidelines.

Effects of changes in alveolar ventilation on isoflurane arterial blood concentration and its uptake into the human body.

We investigated whether minute alveolar ventilation affects isoflurane concentration in arterial blood and uptake of isoflurane into the body. Thirty female patients scheduled to undergo elective gynecological surgery were randomly assigned to one of three groups: i.e. hyperventilation, normal ventilation and hypoventilation. Inspiratory (CIiso) and end-tidal (CEiso) concentrations of isoflurane were measured by infrared analysis, and arterial blood isoflurane concentration (Aiso) was analyzed by gas chromatography. Cardiac index was measured by Doppler ultrasonography. The body uptake of isoflurane was determined by multiplying alveolar ventilation by the gradient of CIiso-CEiso. Aiso was highest in the hyperventilation group (significant), followed by the normal ventilation and hypoventilation groups, during the 40-min study. During the first 10 min of the study, the slope of the Aiso-over-time curve was highest in the hyperventilation group, followed by the normal ventilation group and the hypoventilation group. During the second half of the study (20-40 min), the slope Aiso-over-time curve did not differ among the three groups. Changes in ventilation affected the concentration of isoflurane in arterial blood but did not significantly alter the uptake of it during the last 20 min of the study. The change of alveolar ventilation altered the speed of functional residual capacity wash-in by isoflurane, which was the integral factor influencing Aiso and body uptake of isoflurane.

The effect of heat-moisture exchanger and closed-circuit technique on airway climate during desflurane anesthesia.

PURPOSE: We assessed whether closed-circuit anesthesia (CCA) could provide a more favorable airway climate than semi-closed anesthesia (SCA), and we also determined the beneficial effect of heat moisture exchangers (HMEs) on the preservation of airway climate during desflurane anesthesia. METHODS: Forty patients scheduled for colorectal surgery (n = 10 for each group) were randomized to receive a fresh gas flow of 250 or 3000 ml.min(-1) with or without HMEs. Anesthesia was maintained by adjusting the inspired concentration of 6% desflurane. Absolute moisture and temperature of inspired gases were measured as the baseline value first at 5 min after tracheal intubation, and then at 10, 20, 45, 60, 90, and 120 min after the induction of anesthesia. RESULTS: At 120 min, the inspiratory humidity and temperature were higher in CCA than in SCA. The HME led to major improvements of the humidity (from 22.1 to 35.7 mg H(2)O.l(-1)) and temperature (from 23.6 degrees C to 31.5 degrees C) of anesthetic gases in the CCA group. CONCLUSION: CCA was much more advantageous than SCA for maintaining the patient's airway climate during the 2-h study. The beneficial effect of HME on the airway climate should be emphasized, especially in patients undergoing general anesthesia.

Nitrous oxide uptake in man: a new concept of uptake of inhalation anesthetics.

BACKGROUND: With proper recognition of the functional residual capacity (FRC) and the existence of the alveolar membrane in consideration of gas uptake, the uptake of nitrous oxide does not follow the previously described power function of time, 1,000 ml x t(-1/2). METHODS: By use of a simple subtraction method, nitrous oxide uptake was measured in patients undergoing anesthesia with nitrous oxide in oxygen and a high-dose narcotic for cardiac surgery. RESULTS: When FRC washin was considered separately, the uptake of nitrous oxide which started from zero, reached its peak value at the end of washin, and then diminished slowly. CONCLUSIONS: In contrast to previous publications, in which the time course of FA/FI was used to express the uptake of nitrous oxide, in spite of the area under the curve of FA/FI should not be used to express uptake, instead, the area above the curve, (1-FA/FI), fits the results and should be considered as representing uptake.

The valid time of soda lime could be safely prolonged according to the inspired pressure of carbon dioxide.

BACKGROUND: Carbon dioxide (CO2) absorbent, a disposable chemical mixture enclosed in a canister of anesthetic breathing systems functions to remove the carbon dioxide expired from the patients during general anesthesia. The timing of replacing the exhausted CO2 absorbent is usually decided by discoloration of the indicator dye or the valid time of use. However, these methods are subjective. We designed a study to validate our idea of replacing the exhausted CO2 absorbent according to the inspired pressure of carbon dioxide (PiCO2) and comparison of the pressure difference between the arterial carbon dioxide tension (PaCO2) and end-tidal CO2 in the exhausted and fresh CO2 absorbent circuits. METHODS: Fifty-five adult patients undergoing general anesthesia for elective surgeries were enrolled in this study. All the canisters containing fresh soda lime were labeled with the date of filling and valid time of clinical use. The soda lime was replaced only when the PiCO2 reached 6 mmHg. Before and 20 minutes after the replacement, PaCO2 and end-tidal CO2 were obtained and designated as group-Pre and group-Post, respectively. The pressure differences between PaCO2 and end-tidal CO2 in both groups were checked for statistical analysis. RESULTS: The pressure differences in group-Pre and group-Post were 5.8 +/- 3.4 mmHg and 6.1 +/- 3.3 mmHg, respectively, both of which were not statistically significant (P = 0.62). The PaCO2 in group-Pre and group-Post was 43.7 +/- 4.2 mmHg and 40.9 +/- 4.6 mmHg respectively. The end-tidal CO2 in group-Pre and group-Post was 38 +/- 3.5 mmHg and 35 +/- 3.6 mmHg, respectively. There were significant differences in PaCO2 and end-tidal CO2 between the two groups (P < 0.001). By this determination the valid time of soda lime in Omeda, Cato and Kion anesthesia machines was 57.3 +/- 7.2, 35.6 +/- 6.3 and 21.7 +/- 4.2 hours, respectively, all of which were much longer than 8 hours of routine use previously delimited. CONCLUSIONS: Even though the PiCO2 concentration reached 6 mmHg in the rebreathing circuit with exhausted soda lime, the gradient between the PaCO2 and end-tidal CO2 was of no statistical difference compared with that of the fresh soda lime circuit. Thus the pressure difference was not affected by the exhausted CO2 absorbent in spite of a reach of PiCO2 to 6 mmHg. Under CO2 monitoring, the valid time of soda lime could be safely prolonged until the PiCO2 was elevated to 6 mmHg rather than 8 h strictly pursuant to traditional method of discoloration of indicator dye.

Pharmacokinetics of isoflurane: uptake in the body.

We investigated the effect of the inspired isoflurane concentration (C(I)iso) on body uptake by comparing the isoflurane concentration in the pulmonary artery blood (PAiso) and that in the arterial blood (Aiso) in 16 patients undergoing coronary artery bypass grafting surgery during the 1st, hour of isoflurane anesthesia. The patients received standardized anesthetics consisting of fentanyl and thiopental and were then allocated to receive either 1% or 2% C(I)iso (n = 8 in each group). C(I)iso and end-tidal isoflurane concentration (C(E)iso) were measured by infrared analysis, and Aiso and PAiso were analyzed by gas chromatography. The cardiac output was measured by thermodilution by use of a pulmonary artery catheter. The body tissue could be represented by the gradient C(I)iso-C(E)iso or Aiso-PAiso over time, respectively. The 2% inspired isoflurane group had twice the gradients (either C(I)iso-C(E)iso or Aiso-PAiso) than the 1% inspired isoflurance group. Additionally, both C(I)iso-C(E)iso and Aiso-PAiso were nearly constant over the hour of the study. The inspired concentration-dependent and near-constant uptake of isoflurane over time has important implications which enable us to apply the uptake pattern of isoflurane to clinical practice.

Pharmacokinetics of isoflurane: uptake in the brain.

We studied the effect of the inspired isoflurane concentration (C(I)iso) on the pharmacokinetics of isoflurane uptake in the brain by comparing the isoflurane concentration in internal jugular-bulb blood (Jiso) with that in arterial blood (Aiso), and analyzed this by gas chromatography. Sixteen patients (aged 43-76 years) undergoing colorectal surgery were enrolled, and anesthesia was maintained with a constant C(I)iso of either 1% (group 1, n = 8) or 2% (group 2, n = 8) during the 1st hour of isoflurane anesthesia. Under constant volume-controlled ventilation, we measured the C(I)iso and the end-tidal isoflurane concentration (C(E)iso) at the mouthpiece by infrared analysis. Our results demonstrate that it takes 40 min for the brain tissue concentration to equal Aiso for 1% C(I)iso, and 50 min for 2% C(I)iso. The Aiso (and/or Jiso) for 2% C(I)iso was approximately double when compared to that for 1% C(I)iso. Except during the initial wash-in period of the functional residual capacity in the first 3 min, the differences between C(I)iso and C(E)iso revealed that the body uptake of isoflurane for 2% C(I)iso was twice that for 1% C(I)iso. These results demonstrate that the pharmacokinetics of isoflurane uptake in the brain is time-dependent for Jiso to equal Aiso, and the midpoint between Aiso and Jiso (likely representing the isoflurane concentration in brain tissue) was dependent on C(I)iso.

Minimal low-flow isoflurane-based anesthesia benefits patients undergoing coronary revascularization via preventing hyperglycemia and maintaining metabolic homeostasis.

BACKGROUND: The objectives of this study were to determine whether minimal low-flow isoflurane-based anesthesia could be a feasible technique for patients undergoing coronary artery bypass graft surgery. It is hypothesized that isoflurane-based anesthesia facilitates an agreeable recovery from surgery is mediated through preventing hyperglycemia and metabolic disturbance associated with cardiopulmonary bypass. METHODS: 107 consecutive patients were randomly assigned to two groups, i.e., isoflurane-based anesthesia group (n = 54) and fentanyl-based anesthesia group (control group, n = 53). In isoflurane-based anesthesia group, patients received isoflurane from induction up till departure from operating room to intensive care unit (ICU). In the control group, fentanyl (66.4 +/- 3.2 micrograms/kg) and midazolam (320 +/- 20 micrograms/kg) were administered to anesthetize the patients during the operation. RESULTS: Patients with isoflurane-based anesthesia required less dopamine (0.6 +/- 0.2 vs. 4.2 +/- 0.4 micrograms/min) and dobutamine (0.4 +/- 0.2 vs. 4.1 +/- 0.5 micrograms/min); they could be extubated earlier (7.9 +/- 1.0 vs. 35.1 +/- 2.9 h), and had a shorter stay at ICU (2.2 +/- 0.2 vs. 4.8 +/- 0.4 days). In addition, occurrence of hyperglycemia (167 +/- 7.7 vs. 243 +/- 9.5 mg/dl) and bicarbonate requirement (128 +/- 7.0 vs. 313 +/- 22.0 mEq) were less in patients with isoflurane-based anesthesia as compared with those in fentanyl group. CONCLUSIONS: These results demonstrate that isoflurane, not fentanyl, benefits patients undergoing coronary artery bypass grafting surgery. This benefit perhaps is mediated through maintaining hemodynamic stability and metabolic homeostasis and preventing hyperglycemia.