Sonographic assessment of abdominal vein dimensional and hemodynamic changes induced in human volunteers by a model of abdominal hypertension.

OBJECTIVE: In patients affected by intra-abdominal hypertension, bladder or gastric pressure measurement may be usefully integrated by ultrasounds in order to detect early hemodynamic impairment. The purpose of this study was to search for changes in abdominal vein size and flow induced by intra-abdominal hypertension. DESIGN: Physiologic study. SETTING: Postoperative intensive care unit of a university hospital. SUBJECTS: Sixteen healthy volunteers. INTERVENTIONS: Four echographic assessments of vessel sizes and blood velocities were randomly performed in the following settings: 1) baseline, 2) intra-abdominal hypertension simulated by a tight pelvic stabilizer around the waist, 3) noninvasive ventilation with a facial mask, and 4) intra-abdominal hypertension plus noninvasive ventilation. MEASUREMENTS AND MAIN RESULTS: The model of intra-abdominal hypertension was validated in eight subjects by measuring gastric pressure. During intra-abdominal hypertension, 1) the inferior vena cava was compressed (significant decrease of both anteroposterior and lateral diameters) and deformed (decreased anteroposterior/lateral diameter ratio), and deformation, but not compression, was attenuated by noninvasive ventilation associated with intra-abdominal hypertension; 2) the portal vein was also compressed (decreased diameter); and 3) blood velocities did not change significantly in the inferior vena cava, portal vein, right suprahepatic vein, or right external iliac vein. In the receiver operating characteristic curve analysis, an inferior vena cava section area (normalized for body surface) of lower than 1 cm²/m² discriminated between intra-abdominal hypertension presence and absence with a sensitivity of 65.6% and a specificity of 87.5% (p = .0001). Noninvasive ventilation alone did not significantly affect vein sizes and velocities. The resistive index, calculated by pulse wave Doppler signal from segmental branches of the right renal artery, increased slightly, but significantly, during intra-abdominal hypertension alone, suggesting an increase of intrarenal pressure. CONCLUSIONS: Simulated intra-abdominal hypertension was associated with decreased inferior vena cava section area and increased resistive index in renal arteries. Further studies are now needed to investigate whether these changes may be of value to integrate bladder or gastric pressure measurement in clinical practice.

Diastolic function: the influence of pneumoperitoneum and Trendelenburg positioning during laparoscopic hysterectomy.

BACKGROUND AND OBJECTIVE: Several reports concerning the haemodynamic changes during gynaecologic laparoscopy have been published so far, and the effects of head-down tilt and pneumoperitoneum have not been clearly separated. However, its main effect seems to be an increase in systemic vascular resistance. We investigated how the augmented afterload can affect diastolic function. METHODS: : Our study involved 20 healthy women, classified as having ASA status I: 10 undergoing laparoscopic hysterectomy and 10 undergoing conventional open hysterectomy. Measurements were made in awake patients and after induction of anaesthesia and then repeated after carbon dioxide insufflation and head-down positioning and at the end of surgery. Diastolic function was primarily studied by transthoracic echocardiography. RESULTS: We observed that pneumoperitoneum caused a significant reduction in stroke volume, cardiac output and left ventricular end-diastolic volume; the diastolic filling times showed a progressive reduction in the E-velocity (the velocity of early mitral inflow, corresponding to the ventricular passive filling phase, measured by pulsed-wave Doppler), a prolonged deceleration time and an augmented isovolumetric relaxation time. After head-down tilting, stroke volume, cardiac output and left ventricular end-diastolic volume increased in both laparoscopic hysterectomy and conventional open hysterectomy groups. CONCLUSION: We have found that pneumoperitoneum has important effects on left ventricular volumes, causing a drop in left ventricular end-diastolic volume; it also affects diastolic function with a delay in deceleration time and isovolumetric relaxation time without any effects on intracavitary pressures.

Noninvasive positive-pressure ventilation with different interfaces in patients with respiratory failure after abdominal surgery: a matched-control study.

BACKGROUND: Acute respiratory failure (ARF) is a relatively common complication after abdominal surgery. METHODS: We compared the efficacy of noninvasive positive-pressure ventilation (NPPV) delivered via helmet versus via face mask in patients with ARF after abdominal surgery in 2 intensive care units (31 beds) in the hospital affiliated with the Catholic University of Rome. Twenty-five patients with ARF after abdominal surgery were treated with NPPV via helmet, and the data from those patients were matched with 25 controls chosen from a historical group of 151 patients treated with face mask during the previous 2 years for respiratory complications after abdominal surgery. The matching was done according to age, Simplified Acute Physiology Score II, and the ratio of P(aO(2)) to fraction of inspired oxygen (P(aO(2))/F(IO(2))). NPPV was delivered in pressure support, starting with 10 cm H(2)O, and positive end-expiratory pressure (PEEP) was increased in steps of 2-3 cm H(2)O, up to a maximum of 12 cm H(2)O, in order to maintain an arterial oxygen saturation over 90% with the lowest possible F(IO(2)). RESULTS: NPPV significantly improved P(aO(2))/F(IO(2)) in both groups. Five of 25 helmet patients (20%) and 12 of 25 mask patients (48%) were intubated (p < 0.036). The main cause for NPPV failure in both groups was intolerance (mask 32% vs helmet 12%, p = 0.6). Heart rate, systolic blood pressure, respiratory rate, duration of NPPV, level of pressure support, and PEEP presented no differences between the 2 groups, nor did intensive-care-unit or hospital mortality. Both the helmet and mask interfaces were effective in improving gas exchange and respiratory rate. The global rate of NPPV complications (mask intolerance, major leaks that caused ventilator malfunction, and ventilator-associated pneumonia) was significantly higher in the mask group than in the helmet group (19 patients vs 4 patients, p < 0.03). CONCLUSIONS: NPPV can be an alternative to conventional ventilation in patients with ARF after major abdominal surgery, and helmet use is associated with a better tolerance and a lower rate of complications.

Ketamine: new indications for an old drug.

Ketamine is a non-competitive antagonist to the phencyclidine site of N-methyl-d-aspartate (NMDA) receptor for glutamate, though its effects are mediated by interaction with many others receptors. It has been introduced in clinical use since 1960's but today it is not largely employed as a general anaesthetic for its undesired psychic effects (emergence reactions) occurring in approximately 12% of patients. In the last decade, there has been a renewed interest in the use of subanaesthetic doses of ketamine for the treatment of acute and chronic pain. In the late 1990's, multiple prospective, randomised, controlled study has shown the efficacy of low dose of ketamine for postoperative pain relief, for analgesia during regional or local anaesthesia, and for opioid-sparing effect. At present, non-definitive conclusion can be drawn. More data are needed to define the possible long term effects and the clinical goal of ketamine use.

Physiologic evaluation of different levels of assistance during noninvasive ventilation delivered through a helmet.

OBJECTIVE: To evaluate the effects of various levels of pressure support (PS) during noninvasive ventilation delivered through a helmet on breathing pattern, inspiratory effort, CO2 rebreathing, and comfort. DESIGN: Physiologic study. SETTING: University-affiliated hospital. PATIENTS AND PARTICIPANTS: Eight healthy volunteers. INTERVENTIONS: Volunteers received ventilation through a helmet with four different PS/positive end-expiratory pressure combinations (5/5 cm H2O, 10/5 cm H2O, 15/5 cm H2O, and 10/10 cm H2O) applied in random order. MEASUREMENTS AND RESULTS: The ventilatory respiratory rate, esophageal respiratory rate (RRpes), airway pressure, esophageal pressure tracings, esophageal swing, and pressure-time product (PTP) [PTP per breath, PTP per minute, and PTP per liter] were evaluated. We also measured the partial pressure of inspired CO2 (Pi(CO2)) at the airway opening, mean partial pressure of expired CO2 (Pe(CO2)), CO2 production (V(CO2)), minute ventilation (V(E)) delivered to the helmet (V(E)h), and the true inspired V(E). By subtracting V(E) from V(E)h, we obtained the Ve washing the helmet (V(E)wh). A visual analog scale (from 0 to 10) was used to evaluate comfort. Compared to spontaneous breathing, different levels of PS progressively increased tidal volume (V(T)) and decreased RRpes, reducing inspiratory effort. The increased levels of assistance did not produce significant changes in Pi(CO2), end-tidal CO2, and V(CO2). Pe(CO2) had a slight decrease when increasing the level of PS from 5 to 10 cm H2O (p < 0.05). Despite the presence of constant values of Ve, the increase of PS produced an increase in V(E)wh, without significant differences comparing 10 cm H2O and 15 cm H2O of PS. The subjects had a slight but not significant increase in discomfort by augmenting the level of assistance. At the highest level of PS (15 cm H2O), the discomfort was significantly higher (p < 0.001) than at the other levels of assistance. CONCLUSION: In volunteers, the helmet is efficient in ventilation, allowing a Vt increase and RRpes reduction. A significant discomfort was present only at the highest level of assistance; however, it did not affect patient/ventilator interaction.

Comparison of two methods to assess blood CO2 equilibration curve in mechanically ventilated patients.

In order to compare two mathematical methods to assess the blood CO2 equilibration curve from a single blood gas analysis [Loeppky, J.A., Luft, U.C., Fletcher, E.R., 1983. Quantitative description of whole blood CO2 dissociation curve and Haldane effect. Resp. Physiol. 51, 167-181; Giovannini, I., Chiarla, C., Boldrini, G., Castagneto, M., 1993. Calculation of venoarterial CO2 concentration difference. J. Appl. Physiol. 74, 959-964], arterial and central venous blood gas analyses and oximetry were performed before and after ventilatory resetting, at constant arterial O2 saturation, in 12 mechanically ventilated patients. CO2 equilibration curves obtained from basal arterial blood gas analyses were used to predict arterial CO2 content after ventilatory resetting and vice versa. Internal consistency was very good for both methods and comparable. Method 2 also yielded excellent predictions of changes of arterial pH associated with ventilatory resetting. In determining Haldane effect, method 2 yielded very stable results within the expected range of values, while method 1 yielded a wider spread of results. Method 2 appeared more suitable to determine the Haldane effect in the conditions of the study, probably due to an approach minimizing the effect of potential sources of inaccuracy.

[In-hospital management of victims of chemical weapons of mass destruction]. / La gestione intraospedaliera dei pazienti esposti ad armi chimiche di distruzione di massa.

Emergency situations caused by chemical weapons of mass destruction add a new dimension of risk to those handling and treating casualties. The fundamental difference between a hazardous materials incident and conventional emergencies is the potential for risk from contamination to health care professionals, patients, equipment and facilities of the Emergency Department. Accurate and specific guidance is needed to describe the procedures to be followed by emergency medical personnel to safely care for a patient, as well as to protect equipment and people. This review is designed to familiarize readers with the concepts, terminology and key operational considerations that affect the in-hospital management of incidents by chemical weapons.

A simplified way for the urgent treatment of somatic pain in patients admitted to the emergency room: the SUPER algorithm.

Somatic pain is one of the most frequent symptoms reported by patients presenting to the emergency department (ED), but, in spite of this, it is very often underestimated and under-treated. Moreover, pain-killers prescriptions are usually related to the medical examination, leading to a delay in its administration, thus worsening the patient's quality of life. With our study, we want to define and validate a systematic and homogeneous approach to analgesic drugs administration, testing a new therapeutic algorithm in terms of earliness, safety, and efficacy. 442 consecutive patients who accessed our ED for any kind of somatic pain were enrolled, and then randomly divided into two groups: group A follow the normal process of access to pain-control drugs, and group B follow our SUPER algorithm for early administration of drugs to relieve pain directly from triage. We excluded from the study, patients with abdominal pain referred to the surgeon, patients with headache, recent history of trauma, history of drug allergies, and life-threatening conditions or lack of cooperation. Drugs used in the study were those available in our ED, such as paracetamol, paracetamol/codeine, ketorolac-tromethamine, and tramadol-hydrochloride. Pain level, risk factors, indication, and contraindication of each drug were taken into account in our SUPER algorithm for a rapid and safe administration of it. The Verbal Numeric Scale (VNS) and the Visual Analog Scale (VAS) were used to verify the patient's health and perception of it. Only 59 patient from group A (27.1 %) received analgesic therapy (at the time of the medical examination) compared to 181 patients (100 %) of group B (p < 0.001). Group B patients, received analgesic therapy 76 min before group A subjects (p < 0.01), resulting in a significant lower VNS (7.31 ± 1.68 vs 4.75 ± 2.3; p < 0.001), and a superior VAS after discharge (54.43 ± 22.16 vs 61.30 ± 19.13; p < 0.001) compared to group A subjects. No significant differences concerning side effects were observed between group A and group B patients. Early administration of a pain-control therapy directly from triage is safe and effective, and significantly improves patients perceptions of their own health.

New indications for corticosteroids in intensive care units.

In last years an increasing number of evidences has been gained that inflammatory response plays a major role in critical illness. The acronym SIRS (Systemic Inflammatory Response Syndrome) has been introduced to define the condition in which the inflammatory reaction exceeds local mechanisms of containment and inflammatory mediators invade the bloodstream causing systemic disturbances. Theoretically, the use of corticosteroids offers a potent tool to control the excess of inflammatory reaction, but initial trials on Adult Respiratory Distress Syndrome (ARDS), head trauma, and septic shock showed not only that mortality was unaffected, but also that morbidity could increase. Recently, however, some new studies have suggested that corticosteroids given at dosages lower than those initially tested, could positively affect late stages of ARDS by preventing pulmonary fibrosis, and septic shock by improving hemodynamics and facilitating the weaning from catecholamines. To date, it is not clear whether these effects are related to the correction of an adrenocortical dysfunction.

Noninvasive positive-pressure ventilation vs. conventional oxygen supplementation in hypoxemic patients undergoing diagnostic bronchoscopy.

OBJECTIVE: We have reported previously on the use of noninvasive positive-pressure ventilation (NPPV) to assist spontaneous breathing in high-risk hypoxemic patients (i.e., PaO(2)/fraction of inspired oxygen [FIO(2)] ratio, < or = 100) who are undergoing diagnostic fiberoptic bronchoscopy (FOB). The efficacy of this intervention in patients with less severe forms of hypoxemia (i.e., PaO(2)/FIO(2) ratio, < 200) is unknown. PATIENTS AND METHODS: Twenty-six patients with PaO(2)/FIO(2) ratios < or = 200 who required bronchoscopic BAL for suspected nosocomial pneumonia were entered into the study. Thirteen patients were randomized during FOB to receive NPPV, and 13 patients were randomized to receive conventional oxygen supplementation by Venturi mask. The primary end points were changes in the PaO(2)/FIO(2) ratio during FOB and within 60 min of terminating the procedure. RESULTS AND OUTCOME: At study entry, the two groups were similar in terms of age, simplified acute physiologic score II values, and cardiorespiratory parameters. During FOB, the mean (+/- SD) PaO(2)/FIO(2) ratio increased by 82% in the NPPV group (261 +/- 100 vs 139 +/- 38; p < 0.001) and decreased by 10% in the conventional oxygen supplementation group (155 +/- 24 to 139 +/- 38; p = 0.23). Sixty minutes after undergoing FOB, the NPPV group had a higher mean PaO(2)/FIO(2) ratio (176 +/- 62 vs 140 +/- 38; p = 0.09), a lower mean heart rate (91 +/- 18 vs. 108 +/- 15 beats/min; p = 0.02), and no reduction in mean arterial pressure in comparison to a 15% decrease from the baseline in the control group. One patient in the NPPV group and two patients in the control group required nonemergent intubation. Major bacterial isolates included Staphylococcus aureus (7 of 30 isolates; 23%) and Pseudomonas aeruginosa (12 of 30 isolates; 40%). CONCLUSION: In patients with severe hypoxemia, NPPV is superior to conventional oxygen supplementation in preventing gas-exchange deterioration during FOB with better hemodynamic tolerance.

Effects of non-invasive ventilation on middle ear function in healthy volunteers.

OBJECTIVES: To evaluate the effects of non-invasive ventilation (NIV) with facial mask or helmet on middle ear (ME). DESIGN. Prospective, randomised study. SETTING: University hospital. PARTICIPANTS: Ten healthy subjects randomly allocated in two groups of five subjects each. INTERVENTIONS: NIV for 1 h, with helmet (group H) or facial mask (group M). Flow-triggered pressure support was 10 cmH(2)O, PEEP 5 cmH(2)O, FiO(2) 0.21. MEASUREMENTS AND RESULTS: Impedenzometry was performed before NIV and 5 min after NIV ended; it was repeated 60 min later. In group H the acoustic compliance increased after NIV from 2.0+/-.6 ml to 2.3+/-.6 ml ( P<.01), suggesting that the tympanic membrane became less stiff; 1 h later the compliance returned to basal values (2.0+/-.7 ml); in group M the compliance was unaffected (from 2.0+/-.5 ml to 2.0+/-.4 ml; 1.9+/-.4 ml 1 h later). The acoustic reflex, i.e., the contraction of the stapedial muscle in response to an auditory stimulus, involving the acoustic and facial nerves, was also evaluated during impedenzometry at 250 Hz, 500 Hz, 1,000 Hz, and 4,000 Hz; no significant change of the threshold was observed. CONCLUSIONS: The tympanic membrane is tighten by the tensor tympani and a reversible loosening suggests muscle fatigue in response to the application of intermittent positive pressure applied to the external ear during NIV with helmet. The loss of tensor tympani protective action could theoretically predispose the middle and inner ear to mechanical damage during NIV with helmet, suggesting the use of protective devices (ear plugs) in selective cases requiring long-term, high-pressure treatment.

Noise exposure during noninvasive ventilation with a helmet, a nasal mask, and a facial mask.

OBJECTIVE: To assess noise exposure during noninvasive ventilation (NIV) with different types of interface (helmet, nasal, and facial masks). SUBJECTS AND METHODS: Ten "naive" healthy volunteers underwent NIV at pressure support levels of 10 and 15 cmH2O with: (a) helmet, (b) helmet equipped with HME filters at the junctions between the helmet and the inspiratory and expiratory branches of the respiratory circuit, (c) nasal mask, and (d) facial mask. Noise intensity was assessed with a sound level meter by placing a microphone near the right ear. Noise intensity and degree of discomfort were also assessed subjectively with a visual analogue scale. RESULTS: Inside the helmet noise exceeded 100 dB. Noise intensity was poorly affected by pressure support level and unaffected by the presence of HME filters. During NIV with nasal or facial masks the noise did not exceed 70 dB (i.e., noise was not louder than the usual noise background in ICU). Subjective evaluation of noise intensity mirrored objective measurements; however, the presence of HME filters was associated with the feeling of less noise inside the helmet. The discomfort associated with the helmet did not significantly differ from that associated with the masks. CONCLUSIONS: NIV helmet is associated with significantly greater noise than nasal and facial masks, but is as comfortable as masks, at least in the short term. Medium- and long-term exposure to loud noise may potentially impair ear function and increase the patient's discomfort.

A prospective, blinded evaluation of indexes proposed to predict weaning from mechanical ventilation.

OBJECTIVE: To conduct a blinded evaluation of the predictors of weaning from mechanical ventilation. DESIGN: A prospective clinical study. SETTING: A 23-bed general intensive care unit. PATIENTS: Ninety-three non-selected patients, ventilated for more than 48 h. METHODS: The study had two steps: at first, patients' data were used to select the cut-off value for weaning predictors (the minimal false classification). The cut-off value for each index was prospectively assessed in a group of 52 patients. The predictive performance of these indexes was evaluated by calculating the area under the receiver operating characteristic curve. In the prospective-validation set we used Bayes' theorem to assess the probability of each test in predicting weaning. The physicians making decisions about the weaning process were always unaware of the predictive values. Weaning was considered successful if spontaneous breathing was sustained for more than 48 h after extubation. MEASUREMENTS AND RESULTS: During the first 2 min after discontinuation of mechanical ventilation the following tests were performed: vital capacity, tidal volume, airway occlusion pressure (P(0.1)), minute ventilation, respiratory rate, maximal inspiratory pressure (MIP), respiratory frequency to tidal volume (f/V(T)), P(0.1)/MIP and P(0.1) x f/V(T). The areas under the curve showed that the tests had not the ability to distinguish between successful and unsuccessful weaning. CONCLUSION: Our results show that all the evaluated indexes are poor predictors of weaning outcome in a general intensive care unit population.

Fiberoptic bronchoscopy during noninvasive positive pressure ventilation delivered by helmet.

OBJECTIVE: To evaluate the feasibility and safety of fiberoptic bronchoscopy (FOB) with bronchoalveolar lavage (BAL) during noninvasive positive pressure ventilation (NPPV) delivered by helmet in patients with acute respiratory failure (ARF) and suspected pneumonia. DESIGN AND SETTING: Prospective, clinical investigation in a general intensive care unit (ICU) of a university hospital. PATIENTS AND PARTICIPANTS: Four adult patients with ARF who underwent NPPV via the helmet and required fiberoptic BAL for suspected pneumonia. INTERVENTIONS: NPPV was delivered through the helmet in the pressure support ventilation mode. The specific seal connector placed in the plastic ring of the helmet allowed the passage of the bronchoscope, maintaining assisted ventilation. Arterial blood gas levels, pH, oxygen saturation, respiratory rate, heart rate, and mean arterial blood pressure were monitored during the study. RESULTS: Helmet NPPV avoided gas exchanges deterioration during FOB and BAL, with good tolerance. During the procedure heart rate increased by 5% and mean arterial blood pressure by 7% over baseline; these levels returned to prebronchoscopic values immediately after the withdrawal of the bronchoscope. Endotracheal intubation was never required during the 24 h after the procedure. BAL yielded diagnostic information in three of four patients. CONCLUSIONS: NPPV through the helmet allows a safe diagnostic FOB with BAL in patients with hypoxemic ARF, avoiding gas exchange deterioration, and endotracheal intubation. ELECTRONIC SUPPLEMENTARY MATERIAL: is available if you access this article at http://dx.doi.org/10.1007/s00134-002-1554-5. On that page (frame on the left side), a link takes you directly to the supplementary materials.

A bench study of 2 ventilator circuits during helmet noninvasive ventilation.

OBJECTIVE: To compare helmet noninvasive ventilation (NIV), in terms of patient-ventilator interaction and performance, using 2 different circuits for connection: a double tube circuit (with one inspiratory and one expiratory line) and a standard circuit (a Y-piece connected only to one side of the helmet, closing the other side). METHODS: A manikin, connected to a test lung set at 2 breathing frequencies (20 and 30 breaths/min), was ventilated in pressure support ventilation (PSV) mode with 2 different settings, randomly applied, of the ratio of pressurization time to expiratory trigger time (T(press)/T(exp-trigger)) 50%/25%, default setting, and T(press)/T(exp-trigger) 80%/60%, fast setting, through a helmet. The helmet was connected to the ventilator randomly with the double and the standard circuit. We measured inspiratory trigger delay (T(insp-delay)), expiratory trigger delay (T(exp-delay)), T(press)), time of synchrony (T(synch)), trigger pressure drop, inspiratory pressure-time product (PTP), PTP at 300 ms and 500 ms, and PTP at 500 ms expressed as percentage of an ideal PTP500 (PTP500 index). RESULTS: At both breathing frequencies and ventilator settings, helmet NIV with the double tube circuit showed better patient-ventilator interaction, with shorter T(insp-delay), T(exp-delay), and T(press); longer T(synch); and higher PTP300, PTP500, and PTP500 index (all P < .01). CONCLUSIONS: The double tube circuit had significantly better patient-ventilator interaction and a lower rate of wasted effort at 30 breaths/min.

Neuroendocrine stress response in gynecological laparoscopy: TIVA with propofol versus sevoflurane anesthesia.

STUDY OBJECTIVE: To compare intraoperative and postoperative neuroendocrine stress responses during total intravenous anesthesia (TIVA) using propofol and remifentanil versus sevoflurane anesthesia, during laparoscopic surgery. DESIGN: Prospective, randomized study. SETTING: Tertiary-care university hospital. PATIENTS: 46 ASA physical status I patients undergoing laparoscopic surgery for benign ovarian cysts. INTERVENTION: Patients were randomly allocated to two groups to receive either TIVA (Group A=23) or sevoflurane anesthesia (Group B=23). MEASUREMENTS: Perioperative plasma levels of norepinephrine (NE), epinephrine (E), adrenocorticotropic hormone (ACTH), cortisol, growth hormone (GH), prolactin (PRL), and thyroid hormones (TSH, FT3, FT4) were measured. Blood samples were collected preoperatively, 30 minutes after the beginning of surgery, after extubation, and two and 4 hours after the end of surgery (times 0, 1, 2, 3, and 4). MAIN RESULTS: In Group A, perioperative levels of NE, E, ACTH, cortisol, and GH compared with preoperative values significantly decreased; in Group B they increased (Groups A vs. B: time 1, P<0.001 for all markers; time 2, P<0.001 for E, ACTH, cortisol, and GH; time 3, P<0.01 for cortisol, NE, and E, and P<0.05 for ACTH and GH). Perioperative PRL levels were significantly enhanced in both groups versus preoperative values. In both groups, TSH levels increased while FT3 levels decreased significantly relative to basal values. In both groups, perioperative FT4 levels significantly increased compared with preoperative values. CONCLUSIONS: TIVA inhibited the ACTH-cortisol axis and reduced NE, E, and GH levels, but it enhanced PRL and had a weak effect on thyroid hormone concentrations as compared to sevoflurane anesthesia.

Massive facial edema and airway obstruction secondary to acute postoperative sialadenitis or "anesthesia mumps": a case report.

INTRODUCTION: A case of massive facial edema and airway obstruction secondary to an acute sialadenitis is described that occurred a few hours after a neurosurgical procedure performed in the prone position. Literature on this topic is reviewed. CASE PRESENTATION: A 73-year-old Caucasian woman underwent a right parieto-occipital craniotomy to remove a meningioma. The procedure was performed in the prone position and lasted for 7 hours. One hour after the end of surgery, left submandibular gland swelling was clearly visible and in a few hours, she developed massive facial edema. Imaging (computed tomography and magnetic resonance) showed inflammatory swelling of the submandibular and parotid glands and of the periglandular tissues, undilated excretory ducts, and complete obliteration of the pharynx lumen (pharyngeal mucosa adhered to the endotracheal tube). Analgesics, corticosteroids, and antibiotics were administered. Edema regressed from the 4th postoperative day and the endotracheal tube could be removed on the 7th postoperative day. The patient was discharged from the surgical intensive care unit on the 14th postoperative day and from hospital on the 28th postoperative day. CONCLUSION: THIS IS THE FIRST CASE REPORT IN WHICH ACUTE POSTOPERATIVE SIALADENITIS CAUSED COMPLETE UPPER AIRWAY OBSTRUCTION: only the presence of a tracheal tube avoided the need for an emergency tracheostomy. Since edema evolves insidiously, we recommend caution when removing the endotracheal tube in patients who are acutely developing postoperative sialadenitis.

Effects of PEEP on the intracranial system of patients with head injury and subarachnoid hemorrhage: the role of respiratory system compliance.

BACKGROUND: Positive end-expiratory pressure (PEEP) can be effective in improving oxygenation, but it may worsen or induce intracranial hypertension. The authors hypothesized that the intracranial effects of PEEP could be related to the changes in respiratory system compliance (Crs). METHODS: A prospective study investigated 21 comatose patients with severe head injury or subarachnoid hemorrhage receiving intracranial pressure (ICP) monitoring who required mechanical ventilation and PEEP. The 13 patients with normal Crs were analyzed as group A and the 8 patients with low Crs as group B. During the study, 0, 5, 8, and 12 cm H2O of PEEP were applied in a random sequence. Jugular pressure, central venous pressure (CVP), cerebral perfusion pressure (CPP), intracranial pressure (ICP), cerebral compliance, mean velocity of the middle cerebral arteries, and jugular oxygen saturation were evaluated simultaneously. RESULTS: In the group A patients, the PEEP increase from 0 to 12 cm H2O significantly increased CVP (from 10.6 +/- 3.3 to 13.8 +/- 3.3 mm Hg; p < 0.001) and jugular pressure (from 16.6 +/- 3.1 to 18.8 +/- 3.2 mm Hg; p < 0.001), but reduced mean arterial pressure (from 96.3 +/- 6.7 to 91.3 +/- 6.5 mm Hg; p < 0.01), CPP (from 82.2 +/- 6.9 to 77.0 +/- 6.2 mm Hg; p < 0.01), and mean velocity of the middle cerebral arteries (from 73.1 +/- 27.9 to 67.4 +/- 27.1 cm/sec; F = 7.15; p < 0.001). No significant variation in these parameters was observed in group B patients. After the PEEP increase, ICP and cerebral compliance did not change in either group. Although jugular oxygen saturation decreased slightly, it in no case dropped below 50%. CONCLUSIONS: In patients with low Crs, PEEP has no significant effect on cerebral and systemic hemodynamics. Monitoring of Crs may be useful for avoiding deleterious effects of PEEP on the intracranial system of patients with normal Crs.