Delayed forced air warming prevents hypothermia during abdominal aortic surgery

We have evaluated the efficacy of the delayed forced air warming during abdominal aortic surgery in 18 patients. Patients were allocated randomly to one of two groups: the control group (n = 9) received no intraoperative warming device; the Bair-Hugger group (n = 9) had active skin surface warming with an upper body cover. The device was activated when core temperature decreased to less than 36 degrees C. The reduction in core temperature was 0.6 degrees C during the first hour after induction and 0.4 degrees C during the second hour in both groups. In the control group, core temperature continued to decrease until the end of surgery, whereas in the Bair-Hugger group, the reduction in core temperature stopped after 1 h of warming, and then rewarming began. At the end of surgery, core temperature in the Bair- Hugger group was similar to core temperature before induction, and was higher than core temperature in the control group (P < 0.003).      

Prevention of psychedelic side effects associated with low dose continuous intravenous ketamine infusion

OBJECTIVE: Continuous low dose infusion of intravenous ketamine for postoperative analgesia was often associated with frightening acute psychodysleptic experiences in our patients. We hypothesized they were due to boluses of ketamine accumulated in the infusion line. We evaluated on two successive groups the impact of perfusion line modifications on psychodysleptic side effects occurrence. METHODS: We compared a reference historic group (in which ketamine line was connected to perfusion line) to a second prospective group (in which ketamine line was connected to the venous catheter via an unidirectional valve). RESULTS: Psychodysleptic experiences occurrence decreased from 4 patients of 26 (15%) to 2 of 116 (2%, p = 0.01). Moreover, these experiences were no longer associated with severe anxious symptoms like near death experiences. CONCLUSION: An unidirectional valve must be considered to limit the occurrence of low dose intravenous ketamine infusion associated psychedelic side effects, during postoperative analgesia.     

The reduction of preoperative autologous blood donation for primary total hip or knee arthroplasty: the effect on subsequent transfusion rates

We conducted this quality assurance observational study to examine the effects of a change in policy regarding preoperative autologous blood donation (PABD) and indications for perioperative blood transfusion in patients undergoing primary total hip or knee arthroplasty. Two successive time periods, each including 182 successive patients treated by the same medical team and with standardized anesthesia, were compared. The first study had the following standard transfusion policy: 3 U of PABD collected (n = 119) and liberal autologous transfusion (AT). The second study introduced a specific indication for PABD, on the basis of estimated red blood cell reserve and a life expectancy of more than 10 years; 2 U of PABD was collected (n = 81), and criteria were identical for AT and allogeneic transfusion. We mainly compared the incidence of AT; allogeneic and overall transfusions; the inclusion, admission, and discharge hematocrit values; and the wastage of PABD units. This novel policy increased the number of untransfused patients by a factor of 10 (5.5% vs 56.6%) (P < 0.0001), decreased the number of PABD patients by 30% with a 2.4-fold reduction in AT (30% vs 80%) (P < 0.0001), and did not change allogeneic requirements (13% vs 15%). Although fewer autologous units were collected (172 vs 426), the wastage was higher in Study 2 (46% vs 12%) (P < 0.0001). We conclude that incorporation of patients' individual factors improves the efficiency of transfusion for total hip and total knee arthroplasty surgeries. IMPLICATIONS: We compared two transfusion policies for primary total hip or knee arthroplasties: first, a standard preoperative autologous donation with a liberal autologous transfusion policy; and second, a more restrictive indication for autologous donation that was based on patients' individual factors, with identical criteria for autologous and allogeneic transfusion. We found that this change of policy reduced autologous donation and transfusion with no increase in allogeneic transfusion.     

Impact of Cormack and Lehane's grade on Intubating Laryngeal Mask Airway Fastrach using: a study in gynaecological surgery

OBJECTIVE: To evaluate the impact of Cormack and Lehane grade on the Intubating Laryngeal Mask Airway (LMA-Fastrach) using in women. STUDY DESIGN: Open prospective study. PATIENTS: The study included 115 scheduled gynaecologic surgery women. METHODS: An LMA-Fastrach was systematically performed in patients with a Cormack's grade > or =3 or when Arne's score was > or =7 whatever the Cormack. After induction of anaesthesia and neuromuscular blockade, Cormack's grade was assessed and LMA-Fastrach was inserted. Proper insertion was confirmed by the easiness of assisted ventilation and the normal aspect of the capnographic curve. Intubation through the LMA-Fastrach was carried out with the specific kit's endotracheal tube. More than two attempts were considered as a failure of the technique and an alternative method was performed. The following parameters were noted: age, weight, height, clinical predictors for difficult intubation (Arne et al.'s score), number of LMA-Fastrach insertion, ventilation efficiency through LMA-Fastrach, successful intubation with LMA-Fastrach and oesophageal intubation. RESULTS: Ventilation through the LMA-Fastrach was efficient in 97%. The success rate of intubation was 94.8% (86% on the first attempt). The success rate of ventilation and intubation were not statistically different according to the different Cormack's grades. The obesity (BMI>30) did not change the success rate of ventilation and intubation through the LMA-Fastrach. CONCLUSION: In women with either predicted or unpredicted difficult intubation, the success rates of ventilation and intubation through the LMA-Fastrach don't seem to be influenced by Cormack grade and obesity.     

Transurethral surgery and persistent urinary infection: effect of a single preoperative dose of cefuroxime

To evaluate the efficacy of cefuroxime, a second generation cephalosporin, in minimizing the risk of per and postoperative infection complications in patients with urinary tract infection undergoing transurethral surgery, 86 patients (ASA I, II) with persistent urinary tract infection despite antibiotic therapy were studied. A double blind protocol was followed. Patients were randomly assigned to receive 10 minutes before surgery either I.V. cefuroxime (1.5 g) (group C, n = 39) or placebo (group P, n = 47) the incidence of positive peroperative systematic blood cultures was lower in group C (9.7%) than in group P (25.2%) (p less than 0.001). The incidence of postoperative blood cultures taken when clinical septic signs were present, was significantly lower in group C (0%) than in group P (21.7%) (p less than 0.05). However neither the incidences of both postoperative urinary tract infection at the 48th postoperative hour and the clinical signs of bacteraemia including fever nor the average length of hospitalization were significantly different in the 2 groups. This lack of significant clinical benefit was not explained by the pharmacokinetic properties of this antibiotic. Thus, preoperative administration of a single dose of cefuroxime, reduces the incidence of per and postoperative bacteraemias in ASA I-II patients with persistent urinary tract infection.     

Roles of fentanyl and nitroglycerin in prevention of myocardial ischemia associated with laryngoscopy and tracheal intubation in patients undergoing operations of short duration

The purpose of this study was to evaluate intravenous nitroglycerin given during induction of anesthesia as a means for prevention of myocardial ischemia and hemodynamic changes associated with induction, laryngoscopy, and intubation, in patients with stable angina scheduled for vascular operations of moderate duration. Forty-six patients were randomly assigned to receive either fentanyl, 3 micrograms/kg (group 1, n = 6), fentanyl, 8 micrograms/kg (group 2, n = 20), or fentanyl 3 micrograms/kg plus a continuous intravenous nitroglycerin infusion, 0.9 microgram X kg-1 X min-1 (group 3, n = 20), in addition to thiopental-pancuronium anesthetic induction, prior to laryngoscopy and intubation. The criteria for recognizing myocardial ischemia were the following: horizontal or downsloping ST segment depression equal to or greater than 1 mV, and/or ventricular arrhythmia, on CM5 recording. In group 1, myocardial ischemia occurred during laryngoscopy and intubation in four patients, and mean blood pressure (MBP), heart rate, and mean pulmonary wedge pressure (PCWP) increased significantly (P less than 0.05). Despite greater stability in MBP and heart rate in group 2, myocardial ischemia still occurred in four patients (not significantly different from group 1). Nitroglycerin added to low-dose fentanyl (group 3) produced significant reduction in myocardial ischemia (1/20) when compared with group 1 (P less than 0.01), and significantly greater stability in PCWP during laryngoscopy and intubation in comparison to groups 1 and 2. In patients with stable angina undergoing operations of short duration, the use of nitroglycerin infusion and low-dose fentanyl significantly decreases the incidence of myocardial ischemia associated with induction of anesthesia and tracheal intubation.     

Standard preoxygenation vs two techniques in children

BACKGROUND: Preoxygenation is recommended in pediatric anesthesia but it has been poorly assessed. Fractional expired oxygen concentration (F(ET)O(2)) is a preoxygenation monitor. The aim of this prospective study in children was to compare three techniques of preoxygenation by the measurement of F(ET)O(2). METHODS: Twenty children (6-15 years) were included. F(ET)O(2) was measured with the child in a supine position, holding the face mask. The F(ET)O(2) value was measured after 3 min of calm breathing of room air (baseline) and during the three preoxygenation techniques performed in random order: 3 min of tidal volume breathing using an O(2) flow of 9 l x min(-1) (TV x 3 min)--four deep breaths within 30 s using an O(2) flow of 15 l x min(-1) (4 DB)--eight deep breaths within 1 min using an O(2) flow of 15 l x min(-1) (8 DB). Between each technique, at least 5 min breathing room air was allowed to return to baseline F(ET)O(2). Fisher's exact test was used and P < 0.05 was considered significant. RESULTS: Twenty children were studied (age: 11.5 +/- 3 years, weight: 42 +/- 21 kg). The F(ET)O(2) > or = 90% was found to be 79% in 74 +/- 40 s with TV x 3 min, 11% with 4 DB, and 68% with 8 DB. CONCLUSIONS: In children, Vt x 3 min is the most efficient preoxygenation technique to reach F(ET)O(2) > or = 90%.     

Preoperative assessment for difficult intubation in general and ENT surgery: predictive value of a clinical multivariate risk index

Several clinical multifactorial indexes have been described for predicting difficult laryngoscopy or intubation, or both, mostly in general surgery, and less frequently in ENT surgery. The objective of this study was to develop and validate a single clinical index for prediction of difficulty in tracheal intubation in both ENT and general surgery. We studied a population of 1200 consecutive ENT and general surgical patients. Clinical criteria were tested using univariate and multivariate analysis. Difficult intubation was defined as requiring unusual techniques. Logistic regression identified seven criteria as independent predictors of difficult tracheal intubation; previous history of difficult intubation; pathologies associated with difficult intubation; clinical symptoms of pathological airway; inter-incisor gap and mandible luxation; thyromental distance; head and neck movement; and Mallampati's modified test. Point values were assigned to each of these factors in proportion to regression coefficients representing the relative weight of each predictive intubation difficulty factor, the sum comprising the score. The best predictive threshold was chosen using a receiver operating characteristic curve. We then prospectively studied and validated the score in a population of 1090 consecutive ENT and general surgery patients. The sensitivity and specificity of the predictions were 94% and 96% in general surgery, 90% and 93% in non- cancer ENT surgery, and 92% and 66% in ENT cancer surgery, respectively.