Patricia Yazbeck

Effect of vital capacity manoeuvres on arterial oxygenation in morbidly obese patients undergoing open bariatric surgery.

Background: Arterial oxygenation may be compromised in morbidly obese patients undergoing bariatric surgery. The aim of this study was to evaluate the effect of a vital capacity manoeuvre (VCM), followed by ventilation with positive end‐expiratory pressure (PEEP), on arterial oxygenation in morbidly obese patients undergoing open bariatric surgery. Methods: Fifty‐two morbidly obese patients (body mass index >40 kg m−2) undergoing open bariatric surgery were enrolled in this prospective and randomized study. Anaesthesia and surgical techniques were standardized. Patients were ventilated with a tidal volume of 10 mL kg−1 of ideal body weight, a mixture of oxygen and nitrous oxide (FiO2 = 40%) and respiratory rate was adjusted to maintain end‐tidal carbon dioxide at a level of 30–35 mmHg. After abdominal opening, patients in Group 1 had a PEEP of 8 cm H2O applied and patients in Group 2 had a VCM followed by PEEP of 8 cm H2O. This manoeuvre was defined as lung inflation by a positive inspiratory pressure of 40 cm H2O maintained for 15 s. PEEP was maintained until extubation in the two groups. Haemodynamics, ventilatory and arterial oxygenation parameters were measured at the following times: T0 = before application of VCM and/or PEEP, T1 = 5 min after VCM and/or PEEP and T2 = before abdominal closure. Results: Patients in the two groups were comparable regarding patient characteristics, surgical, haemodynamic and ventilatory parameters. In Group 1, arterial oxygen partial pressure (PaO2) and arterial haemoglobin oxygen saturation (SaO2) were significantly increased and alveolar‐arterial oxygen pressure gradient (A‐aDO2) decreased at T2 when compared with T0 and T1. In Group 2, PaO2 and SaO2 were significantly increased and A‐aDO2 decreased at T1 and T2 when compared with T0. Arterial oxygenation parameters at T1 and T2 were significantly improved in Group 2 when compared with Group 1. Conclusion: The addition of VCM to PEEP improves intraoperative arterial oxygenation in morbidly obese patients undergoing open bariatric surgery.

Can Femoral Artery Pressure Monitoring Be Used Routinely in Cardiac Surgery

OBJECTIVE The purpose of this study was to evaluate the safety of femoral arterial pressure monitoring in cardiac surgery. DESIGN Prospective, observational study. SETTING Cardiac surgery unit (CSU) in a university hospital. PARTICIPANTS Of a total of 2,350 consecutive patients scheduled for elective cardiac surgery with cardiopulmonary bypass, 2,264 patients with femoral artery pressure monitoring were included. INTERVENTIONS A femoral arterial catheter was inserted percutaneously before the induction of anesthesia. The catheter was withdrawn 40 to 96 hours after surgery. It was replaced by a radial artery catheter in patients staying for more than 4 days in the CSU or in case of pulse loss or lower limb ischemia. The catheter was removed and sent for cultures whenever it showed local changes, discharge, or if sepsis was suspected. MEASUREMENTS AND MAIN RESULTS Pain on insertion ranged from 0 to 20 mm on the 100-mm visual analog scale. Complications related to femoral artery cannulation were recorded. No cases of femoral artery thrombosis, lower extremity ischemia, or hematoma requiring surgery were noted. Small hematomas were observed in 3.3% of patients. The incidence of oozing was 2.1% after the insertion of the catheter and 4.9% after its removal. Three cases (0.13%) of serious bleeding occurred; 2 required surgery. Eight percent of catheter tips were sent for culture, and positive bacterial growth was recorded in 18.6% of them. Catheter-related blood stream infection occurred in 0.5% of the total patient population included. CONCLUSIONS Femoral artery pressure monitoring was associated with a low complication rate and, therefore, it can be used routinely in cardiac surgery.

Intracranial Aneurysm and Recessive Polycystic Kidney Disease: The Third Reported Case

OBJECTIVE To highlight the possible association of intracranial aneurysm with autosomal recessive polycystic kidney disease. DESIGN, SETTING, AND PATIENT To our knowledge, this association has been reported only twice in the medical literature. We herein report the case of a 21-year-old man with autosomal recessive polycystic kidney disease, presenting with subarachnoid hemorrhage secondary to a ruptured intracranial aneurysm, at our institution. RESULTS In the presence of only 3 cases in the medical literature, one might conclude they are a simple coincidence. However, should this association exist, such as with the dominant form, then the neurologic prognosis and even the life of young patients may be at stake. CONCLUSIONS Given the devastating consequences of intracranial bleeding in young patients, early neurologic screening may be warranted.

Coma profond aréactif réversible après intoxication par des abats d’un poisson méditerranéen

INTRODUCTION Neurotoxic fish poisoning appears to be a recent phenomenon in the Mediterranean Sea. We report a case of deep non-reactive reversible coma after ingestion of Mediterranean fish innards. CASE REPORT An 80 year-old man, heavy smoker who had a previous cerebral infarct in the posterior territory, was admitted for rapid deterioration of his neurological condition. He started having perioral tingling, then dysarthria, then became quadriparetic, then developed respiratory and hemodynamic failure and within 3-4h, entered a state of deep non-reactive coma with absence of all brainstem reflexes. He started to improve after 20 h and recovered his neurological baseline within 36 h. Later on, he stated that all his symptoms started after he ingested the gonads of a toxic fish, Lagocephalus scleratus. DISCUSSION Tetrodotoxin blocks voltage-gated sodium channels and inhibits the production and propagation of action potentials. This toxin is highly concentrated in the liver, gonads, intestines and skin of this fish that is well-known in Japan (where it is considered as a delicacy) and South-East Asia and seems to have migrated recently to the Mediterranean Sea. There is no known antidote to tetrodotoxin but intensive supportive treatment can be life-saving.

Community- and healthcare-associated infections in critically ill patients: a multicenter cohort study

OBJECTIVE To compare the spectrum of infection, comorbidities, outcomes, and mortality of patients admitted to the intensive care unit (ICU) due to community-acquired or healthcare-associated severe sepsis. METHODS This prospective cohort study was conducted in three university medical centers in Lebanon from February 2005 to December 2006. Patients with severe sepsis were included and followed up until hospital discharge or death. RESULTS One hundred and twenty patients were included of whom 60% had community-acquired infections (CAI) and 40% had healthcare-associated infections (HAI). The most common infection in both groups was pneumonia. Hematologic malignancies were the only comorbidity more prevalent in HAI than in CAI (p=0.047). Fungal infections and extended-spectrum beta-lactamase (ESBL) organisms were more frequent in HAI than in CAI (p=0.04 and 0.029, respectively). APACHE and SOFA scores were high and did not differ between the two groups, nor did the proportion of septic shock, while mortality was significantly higher in the HAI patients than in the CAI patients (p=0.004). On multivariate analysis for mortality, independent risk factors were the source of infection acquisition (p=0.004), APACHE II score (p=0.006), multidrug-resistant Pseudomonas infections (p=0.043), and fungal infections (p=0.006). CONCLUSIONS Severe sepsis and septic shock had a high mortality rate, especially in the HAI group. Patients with risk factors for increased mortality should be monitored and aggressive treatment should be administered.

Pulmonary Migration of a Fragment of Plastic Coating Sheared from a Stylet

BACKGROUND In trauma patients, particularly with head immobilization, tracheal intubation without the use of a stylet may be impossible. OBJECTIVES To report a very rare but potentially fatal complication that may happen in any Emergency Department: fracture of the plastic sheath of an intubation stylet, reported only twice before in the literature. CASE REPORT Two large plastic fragments detached from a stylet while intubating a trauma patient. One piece was removed from the endotracheal tube a few hours later in the operating room. The second fragment migrated asymptomatically into the pulmonary airway. It was successfully retrieved from the right bronchus 24 h later. CONCLUSION This potentially life-threatening event may go unnoticed after intubation if the endotracheal tube is not obstructed by the fragment. Gentle withdrawal of the stylet from the tube is essential to avoid stylet fracture. Careful examination of the stylet after intubation may suggest a stylet fracture.

Subdural hematoma with cranial nerve palsies after obstetric epidural analgesia

We report a case of intracranial subdural hematoma (SDH) with trigeminal and facial nerve paresis in a pregnant woman receiving epidural analgesia without evidence of dural puncture. A 35-year-old patient, with no medical history, was admitted in active labour at 38 weeks of gestation. An epidural catheter was inserted and advanced 3 cm at L3–4 without difficulty or evidence of dural puncture. A test dose of 2% lidocaine 40 mg excluded intrathecal catheter placement and a continuous infusion of bupivacaine and sufentanil was started. Uncomplicated vaginal delivery took place 5 h later, and the patient was discharged home on the second postpartum day. Three days later, she developed a postural occipitofrontal headache. Conservative therapy for mild post-dural puncture headache (PDPH) was started. On postpartum day 9, she presented to the emergency department with headache. An epidural blood patch (EBP) was performed at L4–5 and resulted in 50% improvement of her headache. However, the following morning she was hospitalized urgently for severe headache unrelated to posture, with paraesthesia and numbness of the left side of the face. Magnetic resonance imaging revealed bilateral 10 day-old temporal SDHs. The following day the patient was conscious, afebrile, and with minimal neck stiffness. Left-sided facial weakness had progressed with drooping of the lip, inability to close the eyelid, and weakness of the frontalis, orbicularis oculi and orbicularis oris muscles, with hypoalgesia and hypoesthesia. Kernig and Brudzinsky signs were absent. Bilateral pupillary reactions to light and ocular motility were normal. Neurological examination was otherwise normal, as were electrocardiogram, chest X-ray and laboratory tests. With SDH thickness of <15 mm, an estimated volume of <30 mL, a midline shift of <5 mm, and in the absence of clinical symptoms, the patient was managed conservatively. The trigeminal and facial nerve paresis recovered completely over six months. The association of SDH and trigeminal and facial nerve paresis as a complication of epidural analgesia has not been reported previously. Accidental dural puncture occurs in approximately 1% of the cases and was usually noted at the epidural insertion time. However, in one third of cases, no sign of dural puncture is seen at the catheter insertion time and retrospective diagnosis is made after PDPH appears. Cases of delayed diagnosis have been reported. In the absence of obvious dural puncture, other etiologies such as traumatic brain injury, coagulopathy or intense Valsalva maneuvers should be considered if the patient presents with symptoms suggestive of PDPH. A traumatic etiology was unlikely in our case given the bilateral hematomas, and coagulopathy was eliminated by laboratory tests. Intense and repeated Valsalva maneuvers during labour, leading to elevated intracranial and intraspinal pressures, could explain the subdural bleeding. If accidental dural puncture occurs, cerebrospinal fluid (CSF) may leak into the lumbar perispinal fatty tissue leading to CSF hypotension, arachnoid membrane lacerations or venous rupture, and finally SDH. The role of an EBP in the etiology of SDH in our case is controversial. It was performed to treat PDPH by tamponading the CSF leak. Guido et al. reported improvement in severe focal neurologic deficits with EBP. However, SDHs were found to develop after inadvertent dural puncture even when an EBP was performed. An EBP may exacerbate neurologic symptoms following dural puncture, and may lead to neurologic complications ranging from cranial nerve palsy to coma. The increased epidural and subarachnoid pressure secondary to the injection of blood may damage neural fibres, compromising neural blood flow, and oedema or nerve stretching during pregnancy may further contribute to injury if EBP is performed. The seventh cranial nerve is more liable to stretching, and the third, fourth, sixth and eighth cranial nerves are more affected when CSF loss has occurred. We feel that our patient had an unrecognised dural puncture with CSF leakage that continued in the postpartum period, leading to CSF hypotension and SDH. We consider that the hematoma, not the EBP, was the principal cause of cranial nerve palsies. Earlier EBP might have prevented both the haematoma and the cranial nerves palsies. In cases where clinical history, signs, and symptoms are not clearly consistent with dural puncture, neuroimaging should be strongly considered before performing an EBP.

Myocardial extraction of intracellular magnesium and atrial fibrillation after coronary surgery

BACKGROUND The effects of magnesium loading on the incidence of atrial fibrillation following coronary artery bypass graft surgery (CAGB) are equivocal. None of the previous studies assessed the influence of myocardial extraction of magnesium in these settings. The current trial aims to elucidate whether the incidence of atrial fibrillation following CABG is affected by the preoperative rate of myocardial extraction of magnesium. METHODS The ethical committee approved the study protocol. 113 patients (94 male, mean age 63 ± 11 years) planned for elective CABG surgery under normothermic cardiopulmonary bypass were prospectively included. Preoperative independent variables included preoperative treatment, electrocardiographic abnormalities, left ventricular ejection fraction estimation, left atrial size, creatinine clearance and assays of plasma and intracellular magnesium, calcium, albumin, potassium and ionized calcium, drawn preoperatively from the coronary sinus and the aortic root. The covariates - including the rate of myocardial extraction of magnesium - were entered in a logistic regression model to predict the odds of atrial fibrillation. RESULTS The incidence of post operative atrial fibrillation was 16%. A rate of myocardial extraction of intracellular magnesium ≥ 7% increases fivefold the multivariate risk of postoperative atrial fibrillation (p < .01). Advanced age was also significantly associated to postoperative atrial fibrillation. CONCLUSIONS This study suggests that a preoperative rate of myocardial extraction of intracellular magnesium ≥ 7% could be a new and a potent predictive factor for postoperative atrial fibrillation.

Case/problem-based learning discussion for teaching ethics to anaesthesiology residents.

EDITOR: We have read with great interest the article by Carrero and colleagues [1] comparing lecture-based approach and case/problem-based learning discussion for teaching pre-anaesthetic assessment. The authors found, in two groups of first year anaesthesiology residents, that the effectiveness of the two educational methods differed little in terms of improving participants’ immediate knowledge of the topic of ‘pre-anaesthetic assessment’. They suggested that more studies are needed to evaluate the interest of case/problem-based learning discussion for other topics in anaesthesiology. We have recently reported the application of problem-based learning discussion to teach ethical reasoning in our anaesthesiology residency programme [2]. Ten anaesthesiology residents participated in this activity. They met in small group interactive sessions, with two tutors, to analyse ethical cases experienced by them during their clinical training. Group discussions were based on the identification of ethical conflicts, analysing the contextual features related to the case and taking the appropriate decisions. Learning was reinforced by ethical guidelines and bibliographic references related to anaesthesiology. At the end of the activity, a structured anonymous questionnaire, based on a Likert five-point scale, was distributed to each resident to assess his perception of the educational activity learning advantages. Five problem-based learning sessions were completed. Discussed cases were: (1) A Jehovah witness undergoing complicated cardiac surgery; (2) Informed consent for a regional anaesthesia; (3) Withdrawing life-sustaining therapies in an ICU patient; (4) Confidentiality in a HIV-positive woman; and (5) Organ donation from a brain-dead young patient. According to collected questionnaires, more than 8/10 participants considered that this learning method promoted the debate of ethical issues related to anaesthesia practice and facilitated the identification, analysis and resolution of ethical problems as well as dialogue with implicated persons. The residents perceived favourably small-group discussions, the quality of the references and the acquisition of ethical principals. In conclusion, now that problem-based learning is being introduced into anaesthesiology residents training programmes [1,3,4], our study showed that it may be applied for teaching not only clinical subjects, but also ethical reasoning. We fully agree with Carrero and colleagues [1] that the impact of problem-based learning discussion on long-term acquisition of knowledge, skills and attitude should be defined. As described by these authors, the immediate retention of knowledge could be evaluated by a ‘pre-tests and post-tests’ objective tool. However, an appropriate method to assess the effect of a teaching approach on the acquisition of clinical competences in anaesthesiology remains to be found.

Mental nerve injury following general anaesthesia

EDITOR: A healthy 31-yr-old female with no previous medical history was scheduled for gynaecologic laparoscopy for primary sterility under general anaesthesia. Routine preoperative investigations were unremarkable. The patient was premedicated with 1 mg kg of hydroxyzine (Atarax) administered orally one hour before the induction of anaesthesia. General anaesthesia was induced with 1 mg kg of fentanyl, 2.5 mg kg of propofol and 0.15 mg kg of cisatracurium. The patient was easily ventilated for 3 min via a size 4 clear face mask with soft adjustable cushion (VBM Medizintechnik GmbH, Einsteinstrasse 1. D-72172 Sulz a.N. Germany). No unusual or excessive pressure was exerted on the mask. Intubation of the trachea was easy and the endotracheal tube was fixed with a tape on the upper lip. Following intubation, a size 2 oropharyngeal (Guedel) airway (Intersurgical UK, Wokingham, UK) was inserted and fixed with a tape. The surgical procedure lasted 45 min. Intraand postoperative course were uneventful and the patient was discharged home the same day. Twenty-four hours postoperatively, the patient presented to the anaesthetic department complaining of numbness in her middle lower lip. Clinical assessment showed a loss of temperature and touch perception at the level of her middle lower lip. The patient was followed up and the numbness regressed gradually from her chin cephalad. Complete remission occurred within 2 weeks.