Lumbar plexus terminal branch block, a safe alternative for transfemoral aortic valve implantation. Case report

Transcatheter aortic valve implantation is an alternative treatment for patients with severe aortic stenosis, it is conventionally performed under general anaesthesia or local anaesthesia plus sedation. We present the first case of trans-femoral, trans-catheter aortic valve implantation, performed in our hospital in a patient with severe aortic stenosis, who was a high surgical risk. Anaesthesia consisted of a combination of bilateral selective blockade of the iliohypogastric, ilioinguinal and genitofemoral nerves with the patient awake without sedation, using an ultrasound-guided approach. Transcatheter aortic valve implantation was successful and passed without incident, the patient remained immobile, calm, did not report pain, and sedation or hypnotics were not necessary during dilation of the vascular accesses with the introducer. Standard monitoring demonstrated haemodynamic stability, without cardiovascular repercussions and did not necessitate vasopressor or inotropic drug support. After the intervention, the patient was sent to the Cardiac Intensive Care Unit, where he remained asymptomatic and stable. Subsequently, the patient was admitted to the cardiology ward from where he was discharged without complications.

Effect of Intraoperative High Positive End-Expiratory Pressure (PEEP) With Recruitment Maneuvers vs Low PEEP on Postoperative Pulmonary Complications in Obese Patients: A Randomized Clinical Trial

IMPORTANCE

An intraoperative higher level of positive end-expiratory positive pressure (PEEP) with alveolar recruitment maneuvers improves respiratory function in obese patients undergoing surgery, but the effect on clinical outcomes is uncertain.

OBJECTIVE

To determine whether a higher level of PEEP with alveolar recruitment maneuvers decreases postoperative pulmonary complications in obese patients undergoing surgery compared with a lower level of PEEP.

DESIGN, SETTING, AND PARTICIPANTS

Randomized clinical trial of 2013 adults with body mass indices of 35 or greater and substantial risk for postoperative pulmonary complications who were undergoing noncardiac, nonneurological surgery under general anesthesia. The trial was conducted at 77 sites in 23 countries from July 2014-February 2018; final follow-up: May 2018.

INTERVENTIONS

Patients were randomized to the high level of PEEP group (n = 989), consisting of a PEEP level of 12 cm H2O with alveolar recruitment maneuvers (a stepwise increase of tidal volume and eventually PEEP) or to the low level of PEEP group (n = 987), consisting of a PEEP level of 4 cm H2O. All patients received volume-controlled ventilation with a tidal volume of 7 mL/kg of predicted body weight.

MAIN OUTCOMES AND MEASURES

The primary outcome was a composite of pulmonary complications within the first 5 postoperative days, including respiratory failure, acute respiratory distress syndrome, bronchospasm, new pulmonary infiltrates, pulmonary infection, aspiration pneumonitis, pleural effusion, atelectasis, cardiopulmonary edema, and pneumothorax. Among the 9 prespecified secondary outcomes, 3 were intraoperative complications, including hypoxemia (oxygen desaturation with Spo2 ≤92% for >1 minute).

RESULTS

Among 2013 adults who were randomized, 1976 (98.2%) completed the trial (mean age, 48.8 years; 1381 [69.9%] women; 1778 [90.1%] underwent abdominal operations). In the intention-to-treat analysis, the primary outcome occurred in 211 of 989 patients (21.3%) in the high level of PEEP group compared with 233 of 987 patients (23.6%) in the low level of PEEP group (difference, -2.3% [95% CI, -5.9% to 1.4%]; risk ratio, 0.93 [95% CI, 0.83 to 1.04]; P = .23). Among the 9 prespecified secondary outcomes, 6 were not significantly different between the high and low level of PEEP groups, and 3 were significantly different, including fewer patients with hypoxemia (5.0% in the high level of PEEP group vs 13.6% in the low level of PEEP group; difference, -8.6% [95% CI, -11.1% to 6.1%]; P < .001).

CONCLUSIONS AND RELEVANCE

Among obese patients undergoing surgery under general anesthesia, an intraoperative mechanical ventilation strategy with a higher level of PEEP and alveolar recruitment maneuvers, compared with a strategy with a lower level of PEEP, did not reduce postoperative pulmonary complications.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02148692.

Protective ventilation with high versus low positive end-expiratory pressure during one-lung ventilation for thoracic surgery (PROTHOR): study protocol for a randomized controlled trial

BACKGROUND

Postoperative pulmonary complications (PPC) may result in longer duration of in-hospital stay and even mortality. Both thoracic surgery and intraoperative mechanical ventilation settings add considerably to the risk of PPC. It is unclear if one-lung ventilation (OLV) for thoracic surgery with a strategy of intraoperative high positive end-expiratory pressure (PEEP) and recruitment maneuvers (RM) reduces PPC, compared to low PEEP without RM.

METHODS

PROTHOR is an international, multicenter, randomized, controlled, assessor-blinded, two-arm trial initiated by investigators of the PROtective VEntilation NETwork. In total, 2378 patients will be randomly assigned to one of two different intraoperative mechanical ventilation strategies. Investigators screen patients aged 18 years or older, scheduled for open thoracic or video-assisted thoracoscopic surgery under general anesthesia requiring OLV, with a maximal body mass index of 35 kg/m2, and a planned duration of surgery of more than 60 min. Further, the expected duration of OLV shall be longer than two-lung ventilation, and lung separation is planned with a double lumen tube. Patients will be randomly assigned to PEEP of 10 cmH2O with lung RM, or PEEP of 5 cmH2O without RM. During two-lung ventilation tidal volume is set at 7 mL/kg predicted body weight and, during OLV, it will be decreased to 5 mL/kg. The occurrence of PPC will be recorded as a collapsed composite of single adverse pulmonary events and represents the primary endpoint.

DISCUSSION

PROTHOR is the first randomized controlled trial in patients undergoing thoracic surgery with OLV that is adequately powered to compare the effects of intraoperative high PEEP with RM versus low PEEP without RM on PPC. The results of the PROTHOR trial will support anesthesiologists in their decision to set intraoperative PEEP during protective ventilation for OLV in thoracic surgery.

TRIAL REGISTRATION

The trial was registered in clinicaltrials.gov ( NCT02963025 ) on 15 November 2016.

Association between night-time surgery and occurrence of intraoperative adverse events and postoperative pulmonary complications

BACKGROUND

The aim of this post hoc analysis of a large cohort study was to evaluate the association between night-time surgery and the occurrence of intraoperative adverse events (AEs) and postoperative pulmonary complications (PPCs).

METHODS

LAS VEGAS (Local Assessment of Ventilatory Management During General Anesthesia for Surgery) was a prospective international 1-week study that enrolled adult patients undergoing surgical procedures with general anaesthesia and mechanical ventilation in 146 hospitals across 29 countries. Surgeries were defined as occurring during 'daytime' when induction of anaesthesia was between 8:00 AM and 7:59 PM, and as 'night-time' when induction was between 8:00 PM and 7:59 AM.

RESULTS

Of 9861 included patients, 555 (5.6%) underwent surgery during night-time. The proportion of patients who developed intraoperative AEs was higher during night-time surgery in unmatched (43.6% vs 34.1%; P<0.001) and propensity-matched analyses (43.7% vs 36.8%; P=0.029). PPCs also occurred more often in patients who underwent night-time surgery (14% vs 10%; P=0.004) in an unmatched cohort analysis, although not in a propensity-matched analysis (13.8% vs 11.8%; P=0.39). In a multivariable regression model, including patient characteristics and types of surgery and anaesthesia, night-time surgery was independently associated with a higher incidence of intraoperative AEs (odds ratio: 1.44; 95% confidence interval: 1.09-1.90; P=0.01), but not with a higher incidence of PPCs (odds ratio: 1.32; 95% confidence interval: 0.89-1.90; P=0.15).

CONCLUSIONS

Intraoperative adverse events and postoperative pulmonary complications occurred more often in patients undergoing night-time surgery. Imbalances in patients' clinical characteristics, types of surgery, and intraoperative management at night-time partially explained the higher incidence of postoperative pulmonary complications, but not the higher incidence of adverse events.

CLINICAL TRIAL REGISTRATION

NCT01601223.

New and old tools for abdominal imaging in critically ill patients

Diagnostic imaging technology has advanced considerably during the past two decades. Different imaging techniques have been proposed for abdominal imaging in critically ill patients like plain radiography, sonography, computed tomography (CT), magnetic resonance and positron emission tomography. Sonography has been proven to be effective to detect free intra-peritoneal fluid and it is considered one of the primary diagnostic modalities for abdominal evaluation for trauma assessment. In our opinion sonography should replace other invasive techniques to rapidly triage blunt trauma patients with unstable vital signs and examine the peritoneal cavity as a site of major haemorrhage to expedite exploratory laparotomy. On the other hand, CT has become the imaging modality of choice in hemodynamically stable patients with multisystem blunt and penetrating trauma. New developments in the quantitative analysis of the CT images will improve our knowledge of pathophysiology, diagnostic and therapeutic management of abdominal pathologies in critically ill patients.

A systematic review and individual patient data meta-analysis on intra-abdominal hypertension in critically ill patients: the wake-up project. World initiative on Abdominal Hypertension Epidemiology, a Unifying Project (WAKE-Up!)

Intra-abdominal hypertension (IAH), defined as a pathologically increase in intraabdominal pressure, is commonly found in critically ill patients. While IAH has been associated with several abdominal as well as extra-abdominal conditions, few studies have examined the occurrence of IAH in relation to mortality. The aim of this paper was to evaluate the prognostic role of IAH and its risk factors at admission in critically ill patients across a wide range of settings and countries. An individual patient meta-analysis of all available data and a systematic review of published (in full or as abstract) medical databases and studies between 1996 and June 2012 were performed. The search was limited to "clinical trials" and "randomized controlled trials", "adults", using the terms "intra-abdominal pressure", "intraabdominal hypertension" combined with any of the terms "outcome" and "mortality". All together data on 2707 patients, representing 21 centers from 11 countries was obtained. Data on 1038 patients were not analysed because of the following exclusion criteria: no IAP value on admission (N.=712), absence of information on ICU outcome (N.=195), age <18 or >95 years (N.=131). Data from 1669 individual patients (19 centers from 9 countries) were analyzed in the meta-analysis. Presence of IAH was defined as a sustained increase in IAP equal to or above 12 mmHg. At admission the mean overall IAP was 9.9±5.0 mmHg, with 463 patients (27.7%) presenting IAH with a mean IAP of 16.3±3.4 mmHg. The only independent predictors for IAH were SOFA score and fluid balance on the day of admission. Five hundred thirteen patients (30.8%) died in intensive care. The independent predictors for intensive care mortality were IAH, SAPS II score, SOFA score and admission category. This systematic review and individual patient data meta-analysis shows that IAH is frequently present in critically ill patients and it is an independent predictor for mortality.

A Systematic Review And Individual Patient Data Meta-Analysis On Intraabdominal Hypertension In Critically Ill Patients: The Wake-Up Project World Initiative on Abdominal Hypertension Epidemiology, a Unifying Project (WAKE-Up!)

Background: Intraabdominal hypertension (IAH), defined as a pathologically increase in intraabdominal pressure, is commonly found in critically ill patients. While IAH has been associated with several abdominal as well as extra-abdominal conditions, few studies have examined the occurrence of IAH in relation to mortality. Objective: To evaluate the prognostic role of IAH and its risk factors at admission in critically ill patients across a wide range of settings and countries. Data sources: An individual patient meta-analysis of all available data and a systematic review of published (in full or as abstract) medical databases and studies between 1996 and June 2012 were performed. The search was limited to "clinical trials" and "randomized controlled trials", "adults", using the terms "intraabdominal pressure", "intraabdominal hypertension" combined with any of the terms "outcome" and "mortality". All together data on 2707 patients, representing 21 centers from 11 countries was obtained. Data on 1038 patients were not analysed because of the following exclusion criteria: no IAP value on admission (n=712), absence of information on ICU outcome (n=195), age <18 or > 95 years (n=131). Results: Data from 1669 individual patients (19 centers from 9 countries) were analyzed in the meta-analysis. Presence of IAH was defined as a sustained increase in IAP equal to or above 12 mmHg. At admission the mean overall IAP was 9.9±5.0 mmHg, with 463 patients (27.7%) presenting IAH with a mean IAP of 16.3±3.4 mmHg. The only independent predictors for IAH were SOFA score and fluid balance on the day of admission. Five hundred thirteen patients (30.8%) died in intensive care. The independent predictors for intensive care mortality were IAH, SAPS II score, SOFA score and admission category. Conclusions: This systematic review and individual patient data meta-analysis shows that IAH is frequently present in critically ill patients and it is an independent predictor for mortality.

Impact of respiratory pattern on lung mechanics and interstitial proteoglycans in spontaneously breathing anaesthetized healthy rats

AIM

The aim of this study was to investigate the effect of different pattern of spontaneous breathing on the respiratory mechanics and on the integrity of the pulmonary extracellular matrix.

METHODS

Experiments were performed on adult healthy rats in which different spontaneously breathing pattern was elicited through administration of two commonly used anaesthetic mixtures: pentobarbital/urethane (P/U) and ketamine/medetomidine (K/M). The animals (five per group) were randomized and left to spontaneously breath for 10 min (P/U-sham; K/M-sham) or for 4h (P/U-4h; K/M-4h), targeting the anaesthesia level to obtain a tidal volume of about 8 mL kg(-1) body wt. At the end of the experiment, lung matrix integrity was assessed through determination of the glycosaminoglycans (GAGs) content in the lung parenchyma.

RESULTS

Compared with K/M, anaesthesia with P/U cocktail induced: (1) a higher respiratory rate and minute ventilation attained with lower P(a) CO(2) ; (2) a higher pressure-time-product and work of breathing per minute; (3) a lower static lung compliance; (4) an increased activation of lung tissue metalloproteases; and (5) greater extraction of pulmonary interstitial GAGs.

CONCLUSIONS

This study suggests that the breathing pattern induced by the different anaesthetic regimen may damage the pulmonary interstitium even during spontaneous breathing at physiological tidal volumes.

New and old tools for abdominal imaging in critically ill patients

Diagnostic imaging technology has advanced considerably during the past two decades. Different imaging techniques have been proposed for abdominal imaging in critically ill patients like plain radiography, sonography, computed tomography (CT), magnetic resonance and positron emission tomography. Sonography has been proven to be effective to detect free intra-peritoneal fluid and it is considered one of the primary diagnostic modalities for abdominal evaluation for trauma assessment. In our opinion sonography should replace other invasive techniques to rapidly triage blunt trauma patients with unstable vital signs and examine the peritoneal cavity as a site of major haemorrhage to expedite exploratory laparotomy. On the other hand, CT has become the imaging modality of choice in hemodynamically stable patients with multisystem blunt and penetrating trauma. New developments in the quantitative analysis of the CT images will improve our knowledge of pathophysiology, diagnostic and therapeutic management of abdominal pathologies in critically ill patients.

[A rationale basis for airways conditioning: too wet or not too wet? ]

Medical gases conditioning during mechanical invasive ventilation is nowadays a problem. In fact, in spite of conditioning guidelines, absolute humidity (AH) into 25-35 mg/l, clinical evaluation of the optimal level of airway humidification has not yet been established with certainty. Physiologically, during spontaneous respiration the airway hydric balance, inspiratory AH expiratory AH, is negative of 27 mg/l about. Usually the patients on mechanical ventilation have an expiratory AH of 32-33 mg/l. An overhumidification of inspired gases, positive airway hydric balance, gives anatomic-physiological alterations of airways and lung parenchyma. During invasive mechanical ventilation, the practice of active hot humidifiers has a positive or level airway hydric balance. We think that inspired AH must be equal to expired AH to maintain an airway hydric balance at least level. At last, the temperature of inspired gases, with active hot humidifiers, shouldn't exceed 32-34 degrees C.

Use and nursing of the helmet in delivering non invasive ventilation

Continuous positive end-expiratory pressure (CPAP) and Pressure Support Ventilation (PSV) are commonly used for the therapy of several forms of respiratory failure. CPAP and PSV can be delivered both during invasive respiratory treatment, by means of an endotracheal tube or tracheostomy, and during non invasive respiratory treatment. Non Invasive Ventilation (NIV) is commonly used for the therapy of several forms of respiratory failure (COPD, Weaning period from Invasive Mechanical Ventilation, Cardiogenic Edema,.) and the helmet could be a good new device to deliver it with a better compliance instead the common facial mask without increasing the nurses' workload.

The abdominal compartment syndrome. Clinical relevance

Increased intra-abdominal pressure (IAP) may occur in a number of different situations encountered by intensivists, such as tense ascites, abdominal hemorrhage, use of military antishock trousers, abdominal obstruction, during laparoscopy, large abdominal tumors and peritoneal dialysis.1-3 Both clinical and experimental evidence indicate that increased IAP may adversely affect cardiac, renal, respiratory and metabolic functions.1-5 Despite this, increased IAP is rarely recognized and treated in Intensive Care Unit (ICU) settings. There appears to be two reasons for this: the physiologic consequences of increased IAP are not well know, to most physicians and, more importantly, the capability of easily measuring IAP has not been well documented. In this chapter, we will discuss: 1) the different methods proposed to evaluate IAP in ICU; 2) the physiopathological consequences of increased IAP; 3) the existing clinical data about IAP in critically ill patients. Considering overall our data, we can conclude that: 1) different techniques are available at the bedside to estimate the IAP; 2) the IAP ranges between 10 and 20 cmH2O, substantially increased compared to normal subjects. Most of the patients have IAH, while few of them (<5%) present clinical characteristics of ACS; 3) the IAP is different among different categories of patients and its increase is not limited to surgical patients only; 4) the increase in IAP appears to influence respiratory function, homodynamic, kidney, gut and brain physiology; 5) the IAP seems to be correlated with severity scores but its relation to mortality is controversial; 6) the routine measurements of IAP by means of bladder pressure are not associated with an increased rate of urinary tract infections.

Respiratory mechanics in brain injured patients

BACKGROUND

Brain injured patients have an increased risk of extracerebral organ failure, mainly pulmonary dysfunction. The prevalent cause of pulmonary failure is ventilator associated pneumonia (VAP) which increases morbidity and mortality. The respiratory dysfunction is mainly characterized by the presence of alveolar consolidation of the dependent lobes.

METHODS

We investigated the mechanical changes of the respiratory system and the effects of positive end-expiratory pressure (PEEP) in 10 normal subjects, in 10 brain injured patients without respiratory failure and in 10 brain injured patients with respiratory failure (PaO2/FiO2 lower than 200 mmHg) due to VAP.

RESULTS

We found that: 1) Intra-Abdominal Pressure (IAP) was increased in brain injured patients with or without respiratory failure compared to normal subjects; 2) the Elastance of respiratory system (Est,rs), the Elastance of the chest wall (Est,cw) and Resistance max of the Lung (Rmax,L) increased in brain injured patients independently from the presence of respiratory failure; 3) in brain injured patients with respiratory failure application of 15 cmH2O of PEEP increased the Elastance of the Lung (Est,L), Est,rs and Rmax,L, while did not result in significant alveolar recruitment and oxygenation improvement.

CONCLUSIONS

In conclusion, in brain injured patients 1) the respiratory mechanics is altered; 2) PEEP is uneffective to improve respiratory function in respiratory failure due to ventilator associated pneumonia. Further studies are warranted to better elucidate the pathophysiology and clinical management of respiratory dysfunction in brain injured patients.

[Observing an SSU Em 118 dispatch center for continuous quality improvement. The case of SSUEm 118 Varese]

The present paper highlights quality aspects of the management of an Emergency Health Service Center (SSUEm 118, Varese) in order to identify the corrective measures required in a service that is increasingly close to the citizens real needs and expectations. Data were collected retrospectively on a total 54,301 calls for assistance in the period October 1997-March 1999 from an area covering some 1,300 sq.km with a population of 1,150,000 residents. That resident population was dramatically increased on a daily basis by heavy vehicle traffic particularly on the motorways to the area's many factories and to the Intercontinental Airport Malpensa 2000. The survey employed 7 anaesthetists and resuscitation staff, 14 nurses and 8 Italian Red Cross works from the Emergency Center. The researchers analysed the following phases: call reception and telephone conversation: ambulance dispatch, patient transportation and the alerting of the hospital of destination. The ServFMEA method was used for Quality Control with appropriate dispatch and the conduct and timing of the ambulance service in the Varese SSUEm 118 area. The data collected allowed for a detailed analysis of the accuracy of the information provided over the telephone (over-triage 58%, undertriage 2%), the usefulness of the telephone filter, the colour coding (correct in 40% of cases), pick-up times (5'40" on average) which were related to problems inherent in the ambulance call-out and the way ambulances reached the emergency (BLS 99%, ALS 1%, Air rescue < 1%). It was concluded that Varese SSUEm 118 was effectively and efficiently run in its first 18 months and results were improved as far as they could be given the inadequate funding of the Italian Heatlh Service.

[Comparison of SAPS II, MPM II24 and SAPS in intensive care]

OBJECTIVE

To compare the performance of the new SAPS II, new MPM2 and SAPS in a cohort of patients admitted to our polyvalent ICU.

METHODS

DESIGN

the ability of the SAPS II scoring system to predict the probability of hospital mortality was assessing calibration and discrimination (ROC curve) measures obtained using published coefficients and within relevant subgroups using formal statistic assessment (goodness of fit).

PATIENTS

from May 1997 to May 1998, 420 consecutive patients over 18 years old.

RESULTS

When the parameters based on the standard model were applied, the SAPS II discrimination (area under ROC curve) was = 0.889 and calibration (chi square test) of SAPS II was = 4.448 with p = 0.879; MPM2 chi 2 = 0.9385, p = 0.402 and SAPS chi 2 = 27.089, p = 0.0001. The performance of SAPS II model was very good. Worst predictive accuracy was achieved in trauma and elective surgery patients.

CONCLUSIONS

SAPS II model gave good results in terms of calibration and discrimination. SAPS II has better accuracy then SAPS and MPM2. Concerning the performance of models, large differences were apparent in relevant subgroups: trauma and sepsis patients. Moreover the choice of adequate statistic method to compare intensive care populations appeared to need more research.