Update of the European Society of Anaesthesiology and Intensive Care Medicine evidence-based and consensus-based guideline on postoperative delirium in adult patients

Postoperative delirium (POD) remains a common, dangerous and resource-consuming adverse event but is often preventable. The whole peri-operative team can play a key role in its management. This update to the 2017 ESAIC Guideline on the prevention of POD is evidence-based and consensus-based and considers the literature between 01 April 2015, and 28 February 2022. The search terms of the broad literature search were identical to those used in the first version of the guideline published in 2017. POD was defined in accordance with the DSM-5 criteria. POD had to be measured with a validated POD screening tool, at least once per day for at least 3 days starting in the recovery room or postanaesthesia care unit on the day of surgery or, at latest, on postoperative day 1. Recent literature confirmed the pathogenic role of surgery-induced inflammation, and this concept reinforces the positive role of multicomponent strategies aimed to reduce the surgical stress response. Although some putative precipitating risk factors are not modifiable (length of surgery, surgical site), others (such as depth of anaesthesia, appropriate analgesia and haemodynamic stability) are under the control of the anaesthesiologists. Multicomponent preoperative, intra-operative and postoperative preventive measures showed potential to reduce the incidence and duration of POD, confirming the pivotal role of a comprehensive and team-based approach to improve patients' clinical and functional status.

Congestive heart failure and comorbidity as determinants of colorectal cancer perioperative outcomes

There has been an increase in surgical interventions in frailer elderly with concomitant chronic diseases. The purpose of this paper was to evaluate the impact of aging and comorbidities on outcomes in patients who underwent surgery for the treatment of colorectal cancer (CRC) in Veneto Region (Northeastern Italy). This is a retrospective cohort study in patients ≥ 40 years who underwent elective or urgent CRC surgical resection between January 2013 and December 2015. Independent variables included: age, sex, and comorbidities. We analyzed variables associated with the surgical procedure, such as stoma creation, hospitalization during the year before the index surgery, the surgical approach used, the American Society of Anesthesiologists (ASA) score, and the Charlson Comorbidity Index score. Eight thousand four hundred and forty-seven patients with CRC underwent surgical resection. Patient age affected both pre- and post-resection LOS as well as the overall survival (OS); however, it did not affect the 30-day readmission and reoperation rates. Multivariate analysis showed that age represented a risk factor for longer preoperative and postoperative LOS as well as for 30-day and 365-day mortality, but it was not associated with an increased risk of 30-day reoperation and 30-day readmission. Chronic Heart Failure increased the 30-day mortality risk by four times, the preoperative LOS by 51%, and the postoperative LOS by 33%. Chronic renal failure was associated with a 74% higher 30-day readmission rate. Advanced age and comorbidities require a careful preoperative evaluation and appropriate perioperative management to improve surgical outcomes in older patients undergoing elective or urgent CRC resection.

Correction to: Perioperative Management of Elderly patients (PriME): recommendations from an Italian intersociety consensus

The article Perioperative Management of Elderly patients (PriME).

Italian intersociety consensus on prevention, diagnosis, and treatment of delirium in hospitalized older persons

Delirium is a severe neuropsychiatric syndrome characterized by inattention and global cognitive dysfunction in the setting of an acute medical illness, medical complication, drug intoxication, or drug withdrawal. The most important risk factors are advanced age and dementia, whereas pain, dehydration, infections, stroke, metabolic disturbances, and surgery are the most common triggering factors. Although delirium is a common clinical syndrome in different settings of care (acute care hospitals, inpatient rehabilitation facilities, nursing homes, and hospices), it often remains under-recognized, poorly understood, and inadequately managed. There exists a clear need for improved understanding to overcome cultural stereotypes, and for the development and dissemination of a comprehensive model of implementation of general good practice points. A network of Italian national scientific societies was thus convened (1) to develop a collaborative multidisciplinary initiative report on delirium in elderly hospitalized patients, (2) to focus the attention of health care personnel on prevention, diagnosis, and therapy of patients suffering from delirium, and (3) to make the health services research community and policy-makers more aware of the potential risks of this condition providing a reference for training activities and data collection.

Intravenous fluid therapy for hospitalized and critically ill children: rationale, available drugs and possible side effects

Human beings are constituted mainly of water. In particular, children's total body water might reach 75-80% of their body weight, compared to 60-70% in adults. It is therefore not surprising, that children, especially hospitalized newborns and infants, are markedly prone to water and electrolyte imbalances. Parenteral fluid therapy is a cornerstone of medical treatment and is thus of exceptional relevance in this patient population. It is crucial to appreciate the fact that intravenous fluids are drugs with very different characteristics, different indications, contraindications and relevant side effects. In the present review, we will summarize the physiology and pathophysiology of water and electrolyte balance, underlining the importance and high prevalence of non-osmotic antidiuretic hormone release in hospitalized and critically ill children. Furthermore, we will discuss the characteristics and potential side effects of available crystalloids for the paediatric population, making a clear distinction between fluids that are hypotonic or isotonic as compared to normal plasma. Finally, we will review the current clinical practice regarding the use of different parenteral fluids in children, outlining both the current consensus on fluids employed for resuscitation and replacement and the ongoing debate concerning parenteral maintenance fluids.

Cardiovascular risk assessment in the senior population undergoing anesthesia for non-cardiac surgery

Older patients are underrepresented in major cardiovascular trials, and only relatively healthy elderly patients, with few comorbidities or functional impairments, have been enrolled. As a result, current guidelines are unable to provide evidence-based recommendations for anesthesia treatment of patients aged ≥75 years, undergoing non-cardiac surgical procedures. Effective strategies, aimed at reducing the risk of perioperative cardiac complications, should involve cardiac evaluation using mostly medical history. A key component is the evaluation of active or unstable cardiac conditions, surgical and cardiac risk factors, and functional capacity of the patient.Patient at low cardiac risk, based on clinical features, functional status, and low-risk surgery, do not generally require further cardiac evaluation, and can be operated on safely without further delay. Additional preoperative testing is indicated in patients at intermediate risk, with poor or unclear functional status. Patients at high-risk based on clinical features, poor functional status, undergoing high-risk surgery may benefit from further evaluation with noninvasive/invasive stress testing. In case of emergency surgical procedures, patient or surgery-specific factors dictate the strategy and do not allow further cardiac testing or treatment.Successful perioperative evaluation is best achieved by combining an integrated multidisciplinary approach, with good communication between the patient, anesthesiologist, cardiologist, geriatrician and surgeon.

Lymphocyte subpopulations and intima media thickness in primary antiphospholipd syndrome

The aim of this study was to evaluate a possible association between lymphocyte subsets and intima media thickness (IMT) of carotid arteries in primary antiphospholipid syndrome (PAPS). We used a cross-sectional study on PAPS patients ( n = 18) and healthy controls ( n = 16). IgG anti-cardiolipin antibody (aCL), IgG anti-β2glycoprotein-I (anti-β2GPI), IgG anti-β2glycoprotein-I complexed to oxidized low-density lipoprotein (oxLDL) and to a specific oxidized moiety of LDL (oxLig1), and β2GPI-oxLDL were measured by ELISA. Lymphocyte immunophenotyping was performed using pairs of monoclonal antibodies directly labelled with fluorescein isothiocyanate, or phycoerythrin or phycoerythrin-Texas-red-X. Intima media thickness (IMT) of carotid arteries was determined by high-resolution sonography. Total peripheral blood lymphocytes did not differ between PAPS and controls. Memory CD4+/CD45RO + T cells were lower in PAPS than controls ( P = 0.0007) as well as CD16+56+ natural killer cells ( P = 0.02). In PAPS memory T CD45RO + cells positively correlated with IgG anti-β2GPI-oxLig1 ( P = 0.002) and to IMT of carotid arteries (common carotid P = 0.02, bifurcation P = 0.007). Naïve CD4+/CD45RA+ T cells inversely correlated with β2GPI-oxLDL ( P = 0.009). The relation between IgG anti-β2GPI-oxLig1 and IMT of carotid arteries with memory CD45RO + T lymphocytes suggests a role for the latter in PAPS related atherogenesis.

Lack of association between IgA deficiency and respiratory atopy in young male adults

BACKGROUND

The issue of atopy and increased serum IgE in IgA deficiency is still a matter of debate. The aim of this study was to evaluate the prevalence of IgA deficiency and its relationship with respiratory atopy.

MATERIALS AND METHODS

A retrospective study on 4700 consecutive young males (age range 18-23), who underwent a health screen for admission to the Italian Airforce Academy between 1993 and 1995 was conducted. Serum IgA was measured by immunoturbidimetry and total and specific IgE by fluorescent enzyme immunoassay (Phadiatop FEIA, Pharmacia Cap System). Airway responsiveness was assessed by methacholine challenge.

RESULTS

IgA deficiency was detected in 0.34% (16/4700) subjects and atopy was detected in 8.6% (406/4700). The mean IgA was 243 mg/dl (95% CI 107, 442) in the 406 atopic subjects and 238 mg/dl (95% CI 100, 441) in 1544 controls. Only 6 (37.5%) of the IgA deficient subjects had subnormal IgE levels and 6 were positive in the fluorescent EIA. None of the IgA deficient patients presented with respiratory hyper-reactivity.

CONCLUSION

Atopy is not more prevalent in young male adult IgA deficient subjects, who rather display a high frequency of recurrent sinusitis.

Giant Intracranial Aneurysms Treated With Deep Hypothermia and Circulatory Arrest

The use of deep hypothermic circulatory arrest (DHCA), using groin cannulation with the chest closed (CCDHCA), has improved the surgical treatment of large and giant cerebral aneurysms. Twelve consecutive ASA I-II patients (10 women and 2 men), with a mean age of 35 years (range 14 to 55 y) underwent DHCA for clipping or trapping of their aneurysm (giant, n=10; large, n=2; 42% posterior circulation), under balanced general anesthesia. Intraoperative standard monitors were completed with jugular oxygen saturation, pulmonary artery, pulmonary artery occlusion, central venous pressures, electroencephalography, evoked potentials, and cerebral (subdural), and core temperature. At the start of circulatory arrest, brain temperature was 15.1+/-1.1 degrees C (range 13.5 to 17.5), and core temperature 14.1+/-1.1 degrees C (range 12.7 to 17.0). Mean circulatory arrest time was 26.5+/-13.9 minutes (range 9 to 54) and anesthesia lasted 14+/-1 hours. Only one patient underwent DHCA with standard sternotomy, because of aortic insufficiency. Follow-up (up to 70 mo) revealed no deaths and Glasgow Outcome Scale at 6 months revealed good recovery in 9, moderate disability in 1, and severe disability in 2 patients. Selected patients with large/giant intracranial aneurysms, deemed unapproachable by conventional surgical techniques, were successfully treated using CCDHCA. Mortality rate was 0% and neurologic complications occurred in 25% of the patients.

Anticardiolipin antibody titre and plasma homocysteine level independently predict intima media thickness of carotid arteries in subjects with idiopathic antiphospholipid antibodies

This study evaluated whether IgG anticardiolipin antibody (aCL) titre and traditional risk factors for atherosclerosis bore any relationship to the intima media thickness (IMT) of carotid arteries of patients with idiopathic antiphospholipid antibodies (aPL). IMT was assessed by high-resolution sonography at the common carotid, carotid bifurcation and internal carotid in 42 (13 male, 29 female, mean age 31+/-10 years) aPL subjects, 29 with primary thrombotic antiphospholipid syndrome and 13 with persistence of aPL in the absence of any underlying disorder. In the same subjects the following were measured: plasma fibrinogen (FNG), von Willebrand factor (vWF), plasminogen activator inhibitor (PAI), homocysteine (HC), total cholesterol (CHO), triglycerides (TG), high density and low density lipoprotein (HDL and LDL), platelet numbers and aCL of IgG and IgM isotype. IMT of the internal carotid was greater in males than females (0.48+/-0.03 vs 0.39+/-0.01 mm, P=0.02). IMT of the carotid bifurcation was greater in thrombotic than nonthrombotic subjects (0.50+/-0.02 vs 0.42+/-0.02 mm, P=0.04). By simple regression, IMT of the common carotids correlated with age (P< 0.0001) IgG aCL titre (P=0.001), FNG (P=0.006), LDL (0.01), CHO (0.02) and PAI (P=0.02). IMT of the carotid bifurcation correlated with age (P=0.002), IgG aCL titre (P=0.0002), FNG (P=0.0001), HC (P=0.009), CHO (P=0.02), vWF (P=0.01) and number of thrombotic events (P=0.03). IMT of the internal carotids correlated with age (P=0.002), IgG aCL titre (P=0.0001), FNG (P=0.0008), PAI (P=0.002) and HC (P=0.01). By stepwise multiple regression analysis, IgG aCL titre independently predicted IMT at all carotid segments examined (P always <0.005). In addition, plasma FNG and HC also resulted independent predictors of IMT at the carotid bifurcation (P=0.001 and P<0.0001, respectively) and internal carotid (P=0.03 and P<0.0001, respectively). These data strongly support an atherogenic role for IgG aCL in patients with aPL. Measurement of plasma HC and FNG may help define aPL subjects at higher vascular risk who may require lowering of HC and FNG by vitamin and/or pharmacologic intervention.

Fluids and the neurosurgical patient

Few human data exist concerning the impact of fluid administration on brain pathophysiology. Those factors that influence water movement into the brain are examined, in order to provide reasonable recommendations for peri-operative fluid management in the patients with brain pathology.

Remifentanil provides hemodynamic stability and faster awakening time in transsphenoidal surgery

In this prospective study, we evaluated the effects of remifentanil in ASA I-II patients undergoing transsphenoidal surgery. After the induction of anesthesia, patients were randomly allocated to the Isoflurane (n = 22, 60% nitrous oxide, isoflurane up to 2% end-tidal) or Remifentanil group (n = 21, 60% nitrous oxide, 0.5% end-tidal isoflurane, remifentanil up to 2 microg x kg(-1) x min(-1)). If mean arterial pressure (MAP) increased >80 mm Hg during maximal dosage of isoflurane or remifentanil, labetalol was administered. At the end of anesthesia, extubation and awakening times, respiratory rate, SpO(2), MAP, heart rate, and adverse effects were recorded. Hemodynamics and bleeding (minimal, mild, moderate, severe) were not different between groups. Bleeding grade increased with MAP >80 mm Hg (P < 0.001). Labetalol was administered to 20 patients in the Isoflurane group, and 10 patients in the Remifentanil group (P < 0.01). The dose of labetalol was larger in the Isoflurane group (1.0 +/- 0.6 versus 0.5 +/- 0.7 mg/kg, P < 0.05). Time to extubation did not differ, whereas time to follow commands was shorter in Remifentanil patients (16 +/- 8 versus 10 +/- 2 min, P < 0.01). No adverse effects occurred in the early postoperative period.

IMPLICATIONS

In patients undergoing transsphenoidal surgery, balanced anesthesia with remifentanil (0.22 +/- 0.17 microg x kg(-1) x min(-1)) provides faster awakening time, as compared with large-dose volatile-based anesthesia, without the risk of postoperative opioid respiratory depression.

Intracranial effects of endotracheal suctioning in the acute phase of head injury

In patients with head injury, endotracheal suctioning (ETS) is a potentially dangerous procedure, because it can increase intracranial pressure (ICP). The purpose of this prospective nonrandomized study was to evaluate the impact of ETS on intracranial dynamics in the acute phase of head injury. Seventeen patients with severe head injury (Glasgow Coma Score < or = 8, range 4-8), sedated and mechanically ventilated, were studied during the first week after trauma. Single-pass ETS maneuver (with a 16-French catheter, negative pressure of 100 mm Hg, and duration of less than 30 seconds) was performed 60 seconds after the FiO2 was increased to 100%. After ETS, FiO2 was maintained at 100% for another 30 seconds. Before and after ETS, arterial blood gases and jugular oxygen saturation (S(j)O2), ICP, and mean arterial pressure (MAP) were measured and cerebral perfusion pressure (CPP) was calculated. A total of 131 ETS episodes, which consisted of repeated assessment of each patient, were analyzed. Six patients in 20 cases coughed and/or moved during ETS because of inadequate sedation. After ETS, ICP increased from 20 +/- 12 to 22 +/- 13 mm Hg in well-sedated patients and from 15 +/- 9 to 28 +/- 9 mm Hg in patients who coughed and/or moved (mean change, 2 +/- 6 versus 13 +/- 6 mm Hg, P <.0001). CPP and S(j)O2 increased in well-sedated patients (from 78 +/- 16 to 83 +/- 19 mm Hg, and from 71 +/- 10 to 73 +/- 13%, respectively) and decreased in patients who reacted to ETS (from 79 +/- 14 to 72 +/- 14 mm Hg and from 69 +/- 7 to 66 +/- 9%, respectively), and the differences were significant (mean change, CPP: 5 +/- 14 versus -7 +/- 15 mm Hg, P =.003; (S(j)O2) 2 +/- 5 vs. -3 +/- 5%, P <.0001). In well-sedated patients, endotracheal suctioning caused an increase in ICP, CPP, and S j O 2 without evidence of ischemia. In contrast, in patients who coughed or moved in response to suctioning, there was a slight and significant decrease in CPP and S(j)O2. In the case of patients with head injuries who coughed or moved during endotracheal suctioning, we strongly suggest deepening the level of sedation before completing the procedure to reduce the risk of adverse effects.

Impact of plasma homocysteine and prothrombin G20210 A on primary antiphospholipid syndrome

The prevalence of prothrombin (PT) G20210A and methylenetetrahydrofolate reductase (MTHFR) C677 <-- T was assessed in 40 patients with primary antiphospholipid syndrome (APS) (14 male, 26 female; mean age, 37 +/- 14 years) and in 27 persistent carriers of antiphospholipid antibodies (aPL) (five male, 22 female; mean age, 40 +/- 16 years) without underlying diseases. Non-APS thrombotic patients (n = 100; 47 female, 53 male; mean age, 40 +/- 10 years) and healthy subjects (n = 100; 46 female, 54 male; mean age, 56 +/- 16 years) served as control groups. Plasma homocysteine (HC) (enzyme-linked immunosorbent assay) was measured in all aPL patients and in 51 subjects from the healthy control group (mean age, 38 +/- 16 years). Heterozygous prothrombin PT G20210A was more frequent in the thrombotic group without APS (18%) than in the control (4%), APS (12%) or aPL (11%) groups, whereas homozygous MTHFR C677 <-- T was equally distributed. After genotype sub-grouping, plasma HC was higher in APS patients with homozygous MTHFR C677 <-- T compared with non-homozygous APS patients (22 +/- 5.4 versus 11 +/- 1.3 micromol/l; P < 0.01) and with homozygous MTHFR C677 <-- T controls (22 +/- 5.4 versus 15 +/- 2.0 micromol/l). In the APS group, mean age at first event was lower in homozygous MTHFR C677 <-- T patients than in non-homozygous patients (26 +/- 7.5 versus 36 +/- 13 years; P = 0.008). In the same group, homozygous MTHFR C677 <-- T patients suffered an increased average number of events per person than non-homozygous patients (1.9 versus 1.3; P = 0.04). Heterozygous PT G20210A contributes little to the thrombotic tendency of primary APS whereas plasma HC may influence age at first event and number of events. Measurement of plasma HC in aPL subjects may identify patients at increased thrombotic risk requiring HC lowering.

Antioxidant susceptibility of pathogenic pathways in subjects with antiphospholipid antibodies: a pilot study

The pathogenesis of antiphospholipid antibody (aPL) related thrombosis is multifactorial and includes, amongst others, enhanced coagulation activation measured as prothrombin fragment 1 + 2 (F1 + 2), elevated plasma levels of von Willebrand factor (vWF), plasminogen activator inhibitor (PAI) and endothelin-1 (ET-1) as well as heightened thromboxane generation and lipid peroxidation. To evaluate the antioxidant susceptibility of some of the above pathways, probucol (500 mg/d orally, a cholesterol lowering agent bearing antioxidant properties) was administered for a three week period to 14 subjects with aPL and to seven healthy controls. At baseline aPL participants showed higher plasma levels of vWF (P = 0.006), ET-1 (P = 0.0002) and enhanced urinary excretion of 11-dehydro-thromboxane-B2 (TXB2) (P = 0.0004), F2-isoprostanes (marker of lipid peroxidation) (P = 0.02) and albumin (P = 0.04) than controls. In the aPL group baseline IgG anticardiolipin (aCL) titre positively related with urinary TXB2 (r2 = 0.43, P = 0.01) and inversely with urinary NOx (r2 = -0.6, P = 0.005) whereas urinary NOx and TXB2 were negatively correlated (r2 = -0.42, P = 0.01). After the treatment period significant decreases from baseline values were noted for PAI (P = 0.01), ET-1 (P = 0.006), TXB2 (P = 0.02), F2-isoprostanes (P = 0.01) and albuminuria (P = 0.01) in aPL participants but not in controls. These pilot data support oxidative sensitive mechanisms and a potential role for antioxidant treatment in the pathogenesis of aPL induced vasculopathy.

Efficacy of low dose intravenous immunoglobulins for post-splenectomy treatment of autoimmune haemolytic anaemia in a patient with hereditary spherocytosis

Summary Idiopathic autoimmune haemolytic anaemia developed in a patient with hereditary spherocytosis. The behaviour of some osmotic fragility tests throughout the illness and the efficacy of intravenous immunoglobulins in controlling autoimmune haemolysis which recurred post splenectomy are discussed

[Retinoic acid syndrome. Severe respiratory insufficiency treated with CPAP]

Retinoic acid syndrome is a potentially life-threatening complication of therapy for acute promyelocytic leukemia (APL) with all-transretinoic acid (ATRA). The case of a 55-year old male patient admitted to the hospital because of a bleeding diathesis is reported. APL was diagnosed and he underwent treatment with idarubicin and ATRA (GIMEMA protocol); 24 hrs after ATRA treatment he developed retinoic acid syndrome and was admitted to the Intensive Care Unit because of severe respiratory insufficiency (dyspnoea, tachypnea and severe hypoxemia (SpO2 75%). Pulmonary insufficiency was treated non-invasively with CPAP and the patient recovered from pulmonary distress one week later.

Effects of pneumoperitoneum and reverse Trendelenburg position on cardiopulmonary function in morbidly obese patients receiving laparoscopic gastric banding

We prospectively evaluated the effects of pneumoperitoneum and reverse Trendelenburg position on cardiopulmonary function in 20 ASA physical status II-III morbidly obese patients (body mass index > 35 kg m(-2)) undergoing laparoscopic gastric banding. After general anaesthesia was induced, patients' lungs were ventilated using intermittent positive pressure ventilation (at measurement times, the following parameters were used: tidal volume 12 mL kg(-1) ideal body weight, respiratory rate of 12 bpm, an inspiratory to expiratory time ratio of 1:2). Haemodynamic variables, blood gas parameters, and lung/chest compliance were recorded: in the supine position, after induction of general anaesthesia (T0, baseline) and induction of pneumoperitoneum (T1); after placing the patient in a 25 degree reverse Trendelenburg position (T2); during the surgical time (T3); before deflating the abdomen (T4); after pneumoperitoneum resolution (T5), and before the end of anaesthesia, with the patient supine (T6). The PaO2, PaO2/FiO2 ratio, and lung/chest compliance decreased during the study. After the pneumoperitoneum had been resolved, lung/chest compliance but not oxygenation parameters returned to baseline values. The arterial to end-tidal CO2 tension difference progressively increased from 0.38+/-0.3 kPa (2.85+/-2.25 mmHg) (T0) to 0.63+/-0.3 kPa (4.73+/-2.25 mmHg) (T6). In morbidly obese patients, undergoing laparoscopic gastric banding, a CO2 pneumoperitoneum markedly affected gas exchange and lung/chest compliance, while positioning the patient in a 25 degree reverse Trendelenburg position had no beneficial effects.

[Rhabdomyolysis caused by improper intraoperative positioning. Clinical and medico-legal aspects]

The etiology, diagnosis, pathology and treatment of rhabdomyolysis due to intraoperative malpositioning and the medico-legal implications of physicians involved in the surgical treatment and anesthesia of the patient are described. According to the Italian law, the anesthesiologist is the only physician of the surgery-anesthesia team responsible for the patient's positioning. The anesthesiologist must assume primary responsibility for protecting the patient from iatrogenic injuries due to improper positioning, and/or inadequate preventive measures.

[Anesthesiologic incidents from esophageal intubation. Presentation of three cases and medico-legal evaluation]

Undiagnosed esophageal intubation is still prominently in anesthesia-related morbidity and mortality. Three cases of undiagnosed esophageal intubation taken into consideration for possible anesthesiologic malpractice are presented. A review of the international anesthetic-related morbidity and mortality statistics indicates that this misadventure remains a problem even among anesthesia personnel, a medical population specifically trained in such a procedure. It is not only the frequency of this misadventure but the potential catastrophic consequences for the patient that underline the importance of being able to recognise and correct an esophageal intubation. The reliability of commonly prescribed methods of assessing tracheal tube position is reviewed and the conclusion is drawn that continuous end-tidal carbon dioxide measurement during anesthesia is perhaps the most reliable means under all circumstances for determining proper tube position and should be employed routinely whenever possible.

[Indications for steroid and tirilazad treatment in patients with subarachnoid hemorrhage]

Tirilazad mesylate, a nonglucocorticoid 21-aminosteroid, has been used in two randomized, double-blind, vehicle-controlled trials in Europe, Australia, New Zealand, and in North America in patients with aneurysmal subarachnoid hemorrhage. The first trial has been concluded, enrolled 1023 patients, and demonstrated a dramatic reduction in mortality from 27% to 3% (p = 0.01) in males receiving 6 mg/kg/day tirilazad for 10 days, when compared to vehicle-treated patients. There was also a less incidence of symptomatic vasospasm, and the frequency of hypertensive-hypervolemic-hemodilution therapy was significantly reduced. The reduction in mortality rate was remarkable, however the benefits of treatment with tirilazad were predominantly shown in men rather than in women. This clinical trial suggest that tirilazad mesylate, at a dosage of 6 mg/kg/day, improves overall outcome in aneurysmal subarachnoid hemorrhage patients. Further data from the North America trial and the trial in women receiving higher doses of tirilazad are still pending.

Physiopathological criteria of vasospasm treatment

Cerebral vasospasm following aneurysmal subarachnoid hemorrhage is one of the most important causes of cerebral ischemia, and is the leading cause of death and disability after aneurysmal rupture. The optimal treatment of vasospasm awaits development of agents for blocking or inactivating spasmogenic substances, or blocking arterial smooth muscle contraction. Rheological and/or hemodynamic manipulation using triple-H (hypertensive-hypervolemic-hemodilution) therapy to prevent or reverse ischemic consequences are relatively effective, but complicated and hazardous, and should be viewed principally as interim measures awaiting development of more specific therapies for arterial narrowing.

Mild hypothermia

Recent evidence indicates that the relationship between "brain protection" and the degree of hypothermia is not linear, and even mild reduction of body temperature (i.e. 2-5 degrees C) may provide protection against cerebral ischemia. The protective effects of mild hypothermia have been demonstrated in various animal models of cerebral ischemia, and are encouraging in human studies. At the present time, although there is no randomized clinical trial assessing the benefits of mild hypothermia for intracranial aneurysm clipping, some neurosurgical centers are routinely instituting mild hypothermia before vascular occlusion.

Thrombophilic genotypes in subjects with idiopathic antiphospholipid antibodies--prevalence and significance

To evaluate the significance of common thrombophilic genotypes in subjects with idiopathic antiphospholipid antibodies (aPL) we determined the methylenetetrahydrofolate reductase C677-->T (MTHFR) and factor V A506-->G (FV Leiden) polymorphisms in 49 subjects with idiopathic aPL (57% of whom suffered spontaneous vein thrombosis), in 70 subjects with a history of spontaneous vein thrombosis and in 193 healthy subjects. The prevalence of MTHFR C677-->T+/+ (homozygotes) was 25%, 18% and 17% respectively amongst aPL thrombotics, non aPL thrombotics and controls and that of MTHFR C677-->T+/- (heterozygotes) was 53%, 59% and 53% respectively in the same groups. The prevalence of FV Leiden was higher in aPL thrombotics (14%) and in non aPL thrombotics (18%) than in controls (4%) (p < or = 0.05). APL thrombotics with MTHFR C677-->T+/+ had a lower mean age at first thrombotic event (22 +/- 6 years) than aPL thrombotics with MTHFR C677-->T+/- and non mutated considered together (38 +/- 14 years, p = 0.0004) and than non aPL thrombotics with MTHFR C677-->T+/+ (38 +/- 14 years, p = 0.003). FV Leiden may contribute to the hypercoagulability of a small, albeit significant proportion of thrombotic aPL subjects, whereas the association between MTHFR C677-->T+/+ and aPL may have an impact on age at first occlusive event and suggests a possible pathogenetic interaction.

7.5% hypertonic saline versus 20% mannitol during elective neurosurgical supratentorial procedures

This prospective randomized clinical study was designed to compare the effects of equal volumes of 7.5% hypertonic saline solution (HS) or 20% mannitol (M) on brain bulk and lumbar cerebrospinal fluid pressure (CSFP) during elective neurosurgical procedures (aneurysm, arteriovenous malformation, or tumor). After informed consent, 50 American Society of Anesthesiologists physical Status I (ASA I) patients were randomly assigned to M (n = 25) or HS (n = 25) groups. Anesthesia protocol was identical for both, and variables monitored included mean arterial blood pressure (MAP), heart rate (HR), central venous pressure (CVP), CSF pressure (CSFP), arterial blood gases (PaCO2 30-35 mm Hg), serum sodium, potassium, and osmolality, and diuresis. The study period started before hypertonic solution administration (T0) and ended at the opening of the dura mater or 60 min after T0. Data were assessed with repeated measures analysis of variance and Student t test with Bonferroni correction (p < or = 0.05). MAP and CVP were the same in the two groups. After treatment, osmolality increased, and the increase at T15 was higher in HS-treated patients [316.6 +/- 9.3 vs. 304.0 +/- 12.0 (SD) mOsmol/kg; p < 0.001]. Sodium decreased after M and increased after HS. During the study, brain bulk was always considered satisfactory. CSFP was not different between M and HS groups and significantly decreased overtime (p = 0.0056) with no difference between treatments. The results of the present study demonstrate that hypertonic saline is as effective as mannitol in reducing the brain bulk and the CSFP during elective neurosurgical procedures under general anesthesia.

[Interaction of soda lime and halogenated anesthetics]

The increased use of soda lime for low flow anaesthesia leads to some problems related to the interaction with halogenated agents. These agents may be absorbed by soda lime or degradated according to their water content. Halothane and enflurane, in contact with soda lime, produce some metabolites, but their concentration is low when compared to their own lethal concentration. Sevoflurane degradates to four compounds. Compound A may reach a value between 13.3-42.1 ppm in the inspired fraction: these values are 50-100 times lower than the toxic concentrations. Isoflurane and desflurane are degradable at very low extent. Some case reports of unexpected high carboxyhemoglobin levels during anaesthesia indicate the possibility of CO production from soda lime and baralyme when halogenated agents are used. This reaction occurs only with anaesthetics containing CHF2-moiety (isoflurane, enflurane and desflurane) and when some specific factors make soda lime or baralyme completely dry. Low flow anaesthesia preserves the moisture content of the soda lime and protects from carbon monoxide production, by increasing water content in the circle.

Coagulation activation and fibrinolytic imbalance in subjects with idiopathic antiphospholipid antibodies--a crucial role for acquired free protein S deficiency

To explore the coagulation/fibrinolytic balance and its relation with free protein S (f-PS) in subjects with antiphospholipid antibodies (aPLs) outside the setting of autoimmune inflammatory disorders, we carried out a cross-sectional study on 18 thrombotic patients with primary antiphospholipid syndrome and 18 apparently healthy subjects with persistence of idiopathic aPLs. Prothrombin fragment 1 + 2 (F1 + 2), thrombin-antithrombin complex (TAT) and D-Dimer (D-D) were taken as markers of thrombin generation and fibrin turnover. Mean F1 + 2 levels were higher in thrombotic (p = 0.006) and non-thrombotic subjects (p = 0.0001) than in controls as were those of D-D (p < 0.0001 and p = 0.003 respectively). TAT levels did not differ. Lower mean levels of f-PS were found in thrombotic (p = 0.0006) and non-thrombotic subjects (p = 0.002) than in controls. Within both groups, mean F1 + 2 levels were higher in subjects who had low f-PS levels compared to those with normal f-PS levels (p = 0.01). Gender analysed data revealed blunted tPA release (venous occlusion test) in thrombotic females (from 16.80 +/- 0.79 to 21.3 +/- 3.9 ng/nl, NS) but not in thrombotic males (from 18.2 +/- 2.0 to 33.7 +/- 4.9 ng/ml, p=0.01) nor in asymptomatic subjects of either sex. Also, in both patient groups females had higher mean PAI than males (p < 0.0002) and than control females (p < 0.02). Low free protein S was found in 100% of non-thrombotic and in 90% of thrombotic patients with defective fibrinolysis. These data are consistent with increased thrombin generation, accelerated fibrin turnover and fibrinolysis abnormalities also in asymptomatic carriers of aPLs and highlight a central role for acquired f-PS deficiency in the thrombotic tendency of the antiphospholipid syndrome.

Propofol anaesthesia in spontaneously breathing paediatric patients during magnetic resonance imaging

BACKGROUND

The aim of this study was to evaluate the use of propofol to induce and maintain anaesthesia in spontaneously breathing paediatric patients (age 2 weeks-11 years) during Magnetic Resonance Imaging (MRI) of the CNS.

METHODS

All patients were spontaneously breathing, without intubation, and received supplemental O2. Pulse rate, blood pressure (BP), electrocardiogram and EtCO2 were recorded in all patients, and in 38 subjects SpO2 was also monitored. Patients were divided in 2 groups according to their body weights: Group A (n = 34, bwt < or = 10 kg), and Group B (n = 48, bwt > 10 kg).

RESULTS

Dosage of propofol during the time of induction (from insertion of the i.v. cannula to positioning on the MRI table) was significantly higher in smaller children (Group A; 5.4 +/- 2.2 (SD) mg/kg) as compared to children with bwt above 10 kg (Group B; 3.7 +/- 1.6 mg/kg). Propofol dosage for maintenance of anaesthesia was significantly higher in smaller children (Group A: 10.1 +/- 5.7 vs Group B: 7.1 +/- 3.0 mgkg-1 h-1, P = 0.003). During the time of induction, transient episodes of reduced BP (< or = 20%) occurred in 6 patients in Group A and 2 patients in Group B. During anaesthesia in Group B there was 1 episode of oxygen desaturation (95%), and 3 episodes of short and mild increases of EtCO2(< or = 52 mmHg). No other side effects occurred in any patient. MRI studies were successfully completed, only 3 sequences (Group A) had to be restarted.

CONCLUSION

Propofol can be safely used for total intravenous anaesthesia in children undergoing MRI.

Peri-operative prophylaxis with phenytoin: dosage and therapeutic plasma levels

Early postoperative epilepsy is a frequent complication of supratentorial intracranial surgery. The lack of consensus on prophylaxis of early postoperative seizures with phenytoin (PHT) may be due to the different dosages used in several studies, owing to inadequate therapeutic plasma level. The aim of this study was to evaluate which dosage of PHT can maintain the therapeutic range in the early postoperative period. Twenty patients operated on for supratentorial neoplasms were randomly allocated to receive, during the last hour of the surgical procedure, loading doses of either 10 mg/kg (group A, n = 10) or 15 mg/kg (group B, n = 10) of PHT. PHT infusion rate never exceeded 30 mg/min. Six hours after the loading dose, PHT maintenance treatment (250 mg, i.v., every 8 hours) was started in all patients. PHT plasma levels were evaluated from the end of the intra-operative loading infusion up to 24 h. During the first six hours after the loading dose, phenytoin plasma levels fell below the therapeutic range (10-20 mg/l) in 7 out of the 10 patients receiving 10 mg/kg, while in the patients treated with 15 mg/kg, PHT plasma levels were always in the therapeutic range (P < or = 0.0001). PHT maintenance dose was sufficient to keep plasma levels within the therapeutic range in 8 patients in group A, and in all the patients in group B. It is concluded that a loading dose of 15 mg/kg, followed by postoperative treatment, is necessary to guarantee therapeutic plasma levels of phenytoin in the immediate postoperative period, when seizure risk is very high.

Cerebral ischemia after venous air embolism in the absence of intracardiac defects

Cerebral air embolism occurred in a patient undergoing posterior fossa surgery performed in the sitting position for acoustic neuroma removal. The patient experienced two episodes of venous air embolism, as evidenced by precordial Doppler, end-tidal carbon dioxide reduction, and oxygen desaturation. In both cases, air was aspirated from the central venous catheter; during the second episode there was arterial hypotension and electrocardiogram changes, and air bubbles were visualized in the cerebellar arteries. The patient did not regain consciousness after surgery and developed early tonic-clonic convulsions and electroencephalogram status epilepticus, which was treated with barbiturate coma. Intracardiac septal defects were not detected by transesophageal echocardiography, and computerized tomography of the brain demonstrated multifocal discrete ischemic areas in the cerebral hemispheres. The patient died 6 days after surgery without having regained consciousness. This case appears to represent the occurrence of transpulmonary passage of venous air embolism.

Regional cerebral metabolism of glucose in comatose and vegetative state patients

Regional cerebral metabolism of glucose (rCMRglu) was evaluated in patients who were in a coma and vegetative state to determine the level of brain function during these conditions. rCMRglu was measured in 17 discrete brain regions with (/-) [18F] -fluoro-2-deoxy-D-glucose (FDG) and positrn emission tomography (PET) in 15 patients with ;brain pathology subsequent to cardiorespiratory arrest (CA), head trauma (HT), or brain ischemia (BI) resulting from cerebrovascular accident or brain surgery. Five comatose patients (Coma group, n = 5), and 10 vegetative state patients (VS, patients awake but not aware) were studied. The VA patients were subdivided, according to the length of their VS condition, into a VS group (n = 6, < 3 months if CA or BI patients, or < 12 months if HT patients) and a persistent vegetative state group (PVS, n = 4, > 3 months if CA or BI patients of > 12 months if HT patients.) Ten normal age-matched subjects served as control. Global CMRglu was 6.72 +/- 0.93 (+/-SD) mg/100 g/min in control subjects. It was significantly (p < - 0.001) reduced to 3.70 +/- 61 in coma, to 3.45 +/- in VS, and to 2.33 +/- 0.34 mg/100 g/min in PVS patients. rCMRglu was significantly reduced (p < - 01001) from control values in all the 17 structures surveyed in every patient. In the Coma and VS groups, there was an overlapping of rCMRglu in the majority of the brain structures. (ABSTRACT TRUNCATED AT 250 WORDS)