Noninvasive ventilation outside the intensive care unit from the patient point of view: a pilot study.

BACKGROUND: Noninvasive ventilation (NIV) is increasingly utilized outside the ICU for patients with acute respiratory failure. However, success and failure risk factors and patient safety aspects have been poorly explored in this setting. So far, no study has evaluated the perspective of the patient, despite the known high relevance of patient participation for NIV success. METHODS: We prospectively interviewed (following a standard questionnaire) the patients successfully treated with NIV for acute respiratory failure outside the ICU. Subjects were interviewed 24-48 hours after NIV suspension. EXCLUSION CRITERIA: NIV failure, patient not competent, patient unwilling to participate in the study, patient transferred to the ICU. RESULTS: Forty-five consecutive patients were included in the study. Only 20% participated in the initial setting of NIV parameters. More than 40% reported they never had the possibility to discuss the NIV treatment. Eighty percent reported they were never asked to try another interface. All subjects knew how to call for help, but only one fourth had been trained to remove the mask, and 22% reported not being able at all to remove the mask if needed. One half of the subjects reported having received help immediately when needed, but 15% waited more than 3 min. All subjects reported complications, and 18% reported respiratory worsening while on NIV. CONCLUSIONS: Subjects reported a low level of involvement in the initial setting of NIV treatment, low satisfaction about communication with the caring staff, and a suboptimal safety level in case of emergency.

Perioperative serum brain natriuretic peptide and cardiac troponin in elective intracranial surgery.

BACKGROUND: There are some intracranial insults which are associated with cardiac abnormalities. Studies of these abnormalities have never been carried out in elective intracranial neurosurgery for the removal of brain tumors. Our prospective study aims at quantifying serum cardiac troponin T (cTnT) and N-terminal pro-brain natriuretic peptide (NT-proBNP) before and after elective intracranial neurosurgery for tumor resection in patients with no history of cardiac abnormality. METHODS: Pre- and postoperative serum cTnT and NT-proBNP were measured in 108 patients submitted to elective major intracranial surgery for the removal of neoplastic lesions. We tested potentially predictive models for these biomarker serum levels. RESULTS: cTnT was undetectable both before and after surgery. Median (IQR) basal NT-proBNP was 35 (18-69) pg/mL and 110 (51-191) pg/mL after surgery. In a multiple linear regression model, basal NT-proBNP was predicted by age, gender, BMI, and the presence of "mass effect" (midline shift or effaced perimesencephalic cisterns on preoperative CT scan) (whole model P < 0.0001; R (2) = 0.3502; and Adjusted R (2) = 0.3247). Postoperative NT-proBNP increase was predicted by baseline NT-proBNP level (whole model P < 0.0001; R (2) = 0.5106; and Adjusted R (2) = 0.5052). CONCLUSION: An intracranial mass effect is associated with higher NT-proBNP serum levels in patients with a brain neoplasm. Following elective intracranial surgery for brain tumor resection NT-proBNP values increase.

Intrinsic positive end-expiratory pressure during ventilation through small endotracheal tubes during general anesthesia: incidence, mechanism, and predictive factors.

STUDY OBJECTIVE: To assess the safety of mechanical ventilation and effectiveness of extrinsic positive end-expiratory pressure (PEEP) (PEEPe) in improving peripheral oxygen saturation (SpO2) during direct microlaryngeal laser surgery; to assess the incidence, amount, and nature (dynamic hyperinflation or airflow obstruction) of ensuing intrinsic PEEP (PEEPi); and to find a surrogate PEEPi indicator. DESIGN: Quasiexperimental. SETTING: S. Raffaele Hospital (Milano), November 2009 to December 2010. PATIENTS: Fifty-two adults scheduled for direct microlaryngeal laser surgery. Exclusion criterion is pregnancy. INTERVENTIONS: Twenty-one percent O2 mechanical ventilation through 4.5- to 5.5-mm internal diameter endotracheal tubes; in 29 patients, after measurement of PEEPi, an identical amount of PEEPe was added; and PEEPi. MEASUREMENTS: SpO2, peak (Pawpeak) and plateau (Pawplateau) airway pressure, and end-expiratory carbon dioxide were measured every 5 minutes. Respiratory compliance (Crs) was computed. PEEPi was measured (end-expiratory occlusion method). MAIN RESULTS: PEEPi ≥5 cm H2O occurred in 14 patients (27%) after intubation, in 16 (30%) at the beginning, and in 14 (27.3%) at the end of surgery. Thirty-one patients (59.4%) exhibited PEEPi ≥5 cm H2O on at least 1 time point. PEEPi at the beginning of surgery was positively correlated with Pawplateau, Crs, tidal volume, and body mass index. Body mass index was the only predictor for the occurrence of PEEPi ≥5 cm H2O. At the beginning of surgery, the Pawplateau receiver operating characteristic curve predicting PEEPi ≥5 cm H2O had area under the receiver operating characteristic curve of 0.85; best cutoff value of 15.5 cm H2O (sensitivity, 88.9%; specificity, 75%; correctly classified cases, 86.1%). When PEEPe was applied, in 23 cases (82.1%), total PEEP equaled PEEPe+ PEEPi; in 3 (10.7%), it was lower; and in 2 (7.1%), it was higher. Application of PEEPe increased SpO2 (P< .05) and Crs (P< .05). CONCLUSIONS: During ventilation through small endotracheal tubes, PEEPi (mostly due to dynamic hyperinflation) is common. Hemodynamic complications, barotrauma, and O2 desaturation (reversible with PEEPe) are rare. Pawplateau provided by ventilators is useful in suspecting and monitoring the occurrence of PEEPi and allows detection of lung overdistension as PEEPe is applied.

Acupuncture accelerates recovery after general anesthesia: a prospective randomized controlled trial.

BACKGROUND: Acupuncture anesthesia was created in the 1950's in China and continues to be used there today during most major surgeries. It is widely used in China for such complex operations as brain, heart, and abdominal surgery. It is popular in China because it is economical, practical, and beneficial to the patients. With acupuncture anesthesia there is less bleeding during surgery and there is also quicker post-operative recovery. OBJECTIVE: This randomized prospective study aims at comparing the effect of two acupoints (Yongquan, KI1 and Renzhong, DU26) with sham acupuncture and no acupuncture on the time to recovery of consciousness after general anesthesia by means of the Bispectral Index monitor (BIS). DESIGN, SETTING, PARTICIPANTS AND INTERVENTIONS: This is a prospective randomized controlled study. We randomly assigned 50 patients to 5 groups during recovery from surgical anesthesia. Four groups had acupuncture on KI1 (group A), DU26 (groups B), both KI1 and DU26 (group C), and sham points (group D), and one had no acupuncture (group E). MAIN OUTCOME MEASURES: Bispectral Index (BIS), time to spontaneous eye opening, time to tracheal extubation, and time to following commands were measured as the main outcome measures. RESULTS: Time to spontaneous eye opening differed among groups (P=0.002), as well as time to tracheal extubation (P<0.000 1) and time to following commands (P=0.000 6). BIS values differed significantly among groups both 5 and 10 min after the end of anesthesia (P<0.000 1 and P=0.000 4, respectively). BIS values of groups D and E were lower than those of the other groups and those of group C were higher. The same pattern was observed also 15 and 30 min after the end of anesthesia, although the difference among groups was not significant at these time points (P=0.164 and P=0.104, respectively). CONCLUSION: Acupuncture on DU26 and KI1 accelerates recovery of consciousness after general anesthesia. Moreover, a possible synergistic effect of DU26 and KI1 is suggested. This issue may play a role in the optimization of operating room management and raise interest about the usefulness of acupuncture on unconsciousness states of different nature.

Feasibility of standard mechanical ventilation with low FiO2 and small endotracheal tubes during laser microlaryngeal surgery.

BACKGROUND: No technique can be considered as a gold standard for ventilation during direct laser CO2 laryngeal microsurgery. We evaluated the feasibility of standard ventilation with laser-safe endotracheal tubes (ETTs) and inspired O2 fraction (FiO2) = 0.21 during direct microlaryngoscopy. METHODS: During total intravenous anesthesia, standard mechanical normoventilation was set with FiO2 = 0.21 and 50 mm Hg peak inspiratory pressure limit. If SpO2 was <90% for >2 minutes, FiO2 was increased to 0.3; after 4 minutes it was increased to 0.4; after another 4 minutes, positive end-expiratory pressure (PEEP) could be set at 5 cm H2O; and after another 4 minutes, surgery was stopped if SpO2 remained <90%. RESULTS: We studied 111 consecutive direct microlaryngoscopies on different patients. Four patients (3.6%) suffered minor intraoperative desaturation. Barotrauma was not observed, PEEP was never applied, and surgery was never stopped. Body mass index was independently predictive of the occurrence of intraoperative desaturation. CONCLUSIONS: Standard mechanical ventilation with FiO2 = 0.21 through laser-safe ETTs is feasible during direct microlaryngoscopy.