[The anesthesiological questionnaire for patients in the outpatient context : Investigations on patient state of health after outpatient operations using the anesthesiological questionnaire for patients]

BACKGROUND

The evaluation of German postanesthesia questionnaires is often restricted to inpatient medical care. The anesthesiological questionnaire for patients (ANP) has previously been validated only after medical care of inpatients. Therefore, the aim of the present study was to evaluate the validity of the ANP in the context of outpatient surgery and anesthesia.

METHODS

Data from 4547 patients (mean age 18-89 years, sex: m/f, 55%/45%), scheduled for ambulatory orthopedic and trauma surgery, were analyzed. All patients received a standard induction of anesthesia with propofol, sufentanil and 4 mg dexamethasone. Maintenance of anesthesia was achieved with a balanced technique comprising volatile anesthesia (either sevoflurane or desflurane) and sufentanil. In addition, patients undergoing operations on the anterior cruciate ligament received a femoral nerve block with 12-15 ml 0.5% ropivacaine. Of the patients 13% remained in hospital overnight as a result of complex operations (combined anterior and posterior cruciate ligament repair, hip arthroscopy and 10% of those undergoing shoulder operations). Before discharge from the recovery room, patients were asked to answer questions with respect to postoperative symptoms 1h after anesthesia (ESNA 19 items), at the time of interview (ABZ 17 items) and about overall patient satisfaction (10 items). These results were matched with the type of procedure and time data from the patient administration system. All data were analyzed descriptively using parametrical tests.

RESULTS

At both time points, pain in the area of the operation was the predominant symptom (ESNA: 77,1%; ABZ: 74,3%). Pain after shoulder arthroscopy was more severe compared to knee arthroscopy, both with and without repair of the anterior cruciate ligament. Most of the adverse symptoms decreased significantly (p ≤ 0.001) with time, demonstrating progressive recovery of the patient. Patient discomfort was more likely to occur in female than in male patients, and female patients were more likely to be dissatisfied with the progress of recovery. The risk of experiencing adverse symptoms after anesthesia was higher for female than for male patients; this was most apparent for feeling cold (odds ratio, OR 4.08) and nausea and vomiting (OR 3.45). Younger patients (18-40 years) were more likely to express discomfort than both groups of older patients (41-60 years and 61-89 years). Accordingly, younger patients had lower satisfaction levels with respect to both anesthesia and overall perioperative care, and the progress of recovery. Postoperative nausea and vomiting (PONV) were linked to younger age, female sex, and longer procedure times (>40 min).

CONCLUSION

The individual analyses delivered plausible results, which support the validity of the ANP. The ANP may also be used for assessment of postoperative discomfort and patient satisfaction in the setting of outpatient surgery. In view of the short time interval between the two measurement points, the ANP for outpatients could in future be reduced to a single postoperative questionnaire.

Prospective randomized comparison of the new Laryngeal Tube Suction LTS II and the LMA-ProSeal for elective surgical interventions

BACKGROUND AND AIM

The Laryngeal Tube Suction (LTS) has recently undergone considerable changes in design. The new LTS II was compared with the LMA-ProSeal to determine device performance during general anaesthesia and controlled ventilation.

METHODS

After Institutional Review Board approval, 100 elective surgical patients were randomized to be ventilated with LTS II or LMA-ProSeal. The number of attempts (maximum of two, and then other device tested) and time until first tidal volume were recorded. Ventilation was standardized (tidal volume, 7 ml/kg; respiratory rate, 12 breaths/min) and the resulting end-tidal CO(2) was recorded. The airway leak pressure (maximum of 40 cmH(2)O) was measured at cuff pressures of 60 cmH(2)O. The ease of gastric tube insertion was evaluated. The devices were inspected for traces of blood after removal. Patients were questioned regarding post-operative complaints. The Mann-Whitney U-test was used to compare the groups.

RESULTS

The demographic data, American Society of Anesthesiologists' group, Mallampati score, and haemodynamic and respiratory variables were comparable for both groups of 50 patients. Insertion was successful in the first/second attempts in 44/4 patients for LTS II and in 43/6 patients for LMA-ProSeal. After two failed attempts, the other device was successfully used in one patient for LMA-ProSeal and in two patients for LTS II. The times until first tidal volume for LTS II and LMA-ProSeal were 25.0 +/- 10.1 and 25.5 +/- 11.5 s, respectively. The airway leak pressures were comparable: 33.1 (15-40) and 32.0 cmH(2)O (18-40 cmH(2)O) for LTS II and LMA-ProSeal, respectively. Gastric tube insertion failed in two patients in each group. Traces of blood were found in two patients with LTS II and in three patients with LMA-ProSeal. In both groups, post-operative complaints were mild and infrequent.

CONCLUSION

In this prospective randomized trial, LMA-ProSeal and LTS II were comparable in all respects.

[Reliability and validity of the Anaesthesiological Questionnaire for electively operated patients]

OBJECTIVE

The Anaesthesiological Questionnaire (ANP) is a self-rating method for the assessment of postoperative complaints and patient satisfaction. The questionnaire consists of two parts. Part 1 assesses the intensity of symptoms regarding the postoperative period in the "recovery-room and the first hours on the ward" (19 items) and the "current state" (17 items). Part 2 assesses patient satisfaction with the anaesthetic care as well as the unspecific perioperative care and postoperative convalescence. The questionnaire was designed to fulfill the criteria of reliability and validity and to serve as a practicable means of auditing the quality of routine clinical practice.

METHODS

A total of 1,112 patients older than 18 years completed the questionnaire after an elective operation. Additionally data concerning the type of anaesthesia were recorded from the anaesthesia chart. To determine retest-reliability, 94 patients competed the ANP twice postoperatively.

RESULTS

The participants of the survey represented 74.6% of the total collective. Out of 19 items 16 had a retest-reliability of r(tt)>0.70, the 3 other items had a reliability of r(tt)>0.50. Reliability (Cronbach's Alpha) of the patient satisfaction scales was between r(tt)=0.76 and r(tt)=0.91. In relation to the period immediately after anaesthesia,women reported more postoperative complaints than men but no differences were found between male and female patients with regard to satisfaction with perioperative care. Younger patients (18-49 years old) described more postoperative complaints than older patients and a lesser degree of satisfaction with perioperative care. There were plausible differences in postoperative complaints between patients who received general vs. regional anaesthesia. Patients reported less postoperative complaints after TIVA than after volatile anaesthetics. The configuration of patient characteristics and anaesthesia gives indications to "risk groups" who predominantly suffer after anaesthesia.

CONCLUSIONS

The Anaesthesiological Questionnaire (ANP) is a reliable and valid method for the assessment of postoperative complaints and patient satisfaction.

Intubating laryngeal mask airway, laryngeal tube, 1100 ml self-inflating bag-alternatives for basic life support?

Insufficient oxygenation, ventilation and gastric inflation with subsequent regurgitation of stomach contents is a major hazard of bag-valve-face mask ventilation during the basic life support phase of cardiopulmonary resuscitation (CPR). The European Resuscitation Council has recommended smaller tidal volumes of approximately 500 ml as an effort to reduce gastric inflation; furthermore, the intubating laryngeal mask airway and the laryngeal tube have been recently developed in order to provide rapid ventilation and to secure the airway. The purpose of our study was to examine whether usage of a newly developed medium-size self-inflating bag (maximum volume, 1100 ml) in association with the intubating laryngeal mask airway, and laryngeal tube may provide adequate lung ventilation, while reducing the risk of gastric inflation in a bench model simulating the initial phase of CPR. Twenty house officers volunteered for our study. When using the laryngeal tube, and the intubating laryngeal mask airway, respectively, the medium-size (maximum volume, 1100 ml) versus adult (maximum volume, 1500 ml) self-inflating bag resulted in significantly (P<0.05) lower mean+/-S.E.M. lung tidal volumes (605+/-22 vs. 832+/-4 ml, and 666+/-27 vs. 887+/-37 ml, respectively), but comparable peak airway pressures. No gastric inflation occurred when using both devices with either ventilation bag. In conclusion, both the intubating laryngeal mask airway and laryngeal tube in combination with both an 1100 and 1500 ml maximum volume self inflating bag proved to be valid alternatives for emergency airway management in a bench model of a simulated unintubated cardiac arrest victim.

[Emergency airway management-- comparison of various strategies in an unsecured airway]

OBJECTIVES

Gastric inflation and regurgitation of stomach contents are major hazards of bag-valve-mask ventilation in an emergency. The purpose of our study was to determine lung ventilation and gastric inflation when using the bag-valve-face mask, laryngeal mask, and combitube with different sizes of self-inflating bags (max. volume: 700, 1100, 1500 ml).

METHODS

Twenty-six training emergency doctors without prior extensive training in emergency airway management volunteered for our study and ventilated a bench model simulating an unintubated respiratory arrest patient with bag-valve-face mask, laryngeal mask, and combitube using paediatric, medium size, and adult self-inflating bags. Lung and gastric tidal volume, as well as lung and gastric peak airway pressure were measured with respiratory monitors and a pneumotachometer.

RESULTS

When using either the combitube or the laryngeal mask, the paediatric vs. medium-size and adult self-inflating bag resulted in significantly (P < .001) lower mean +/- SEM lung tidal volumes (328 +/- 34 vs. 626 +/- 65 vs. 654 +/- 69 ml; and 368 +/- 30 vs. 532 +/- 48 vs. 692 +/- 67 ml, respectively). No gastric inflation occurred with the combitube, while gastric inflation was comparably low when using the laryngeal mask with either ventilation bag (3 +/- 2 vs. 7 +/- 4 vs. 6 +/- 3 ml; P = NS). The paediatric vs. medium-size and adult self-inflating bag in combination with the bag-valve-face mask resulted in comparable lung tidal volumes (250 +/- 23 vs. 313 +/- 24 vs. 282 +/- 38 ml; P = NS); but significantly (P < .01) lower gastric tidal volumes (147 +/- 23 vs. 206 +/- 24 vs. 267 +/- 23 ml).

CONCLUSIONS

Both the laryngeal mask and the combitube proved to be valid alternatives for the bag-valve-face mask in our experimental model. The medium size self-inflating bag seems to be adequate when using either the laryngeal mask or the combitube.

Emergency airway management by non-anaesthesia house officers--a comparison of three strategies

OBJECTIVES

The purpose of this study was to determine effects of different airway devices and tidal volumes on lung ventilation and gastric inflation in an unprotected airway.

METHODS

Thirty one non-anaesthesia house officers volunteered for the study, and ventilated a bench model simulating an unintubated respiratory arrest patient with bag-valve-facemask, laryngeal mask airway, and combitube using paediatric and adult self inflating bags.

RESULTS

The paediatric versus adult self inflating bag resulted with the laryngeal mask airway and combitube in significantly (p<0.001) lower mean (SEM) lung tidal volumes (376 (30) v 653 (47) ml, and 368 (28) v 727 (53) ml, respectively). Gastric inflation was zero with the combitube; and 0 (0) v 8 (3) ml with the laryngeal mask airway with low versus large tidal volumes. The paediatric versus adult self inflating bag with the bag-valve-facemask resulted in comparable lung tidal volumes (245 (19) v 271 (33) ml; p=NS); but significantly (p<0.001) lower gastric tidal volume (149 (11) v 272 (24) ml).

CONCLUSIONS

The paediatric self inflating bag may be an option to reduce the risk of gastric inflation when using the laryngeal mask airway, and especially, the bag-valve-facemask. Both the laryngeal mask airway and combitube proved to be valid alternatives for the bag-valve-facemask in this experimental model.

Effectiveness of various airway management techniques in a bench model simulating a cardiac arrest patient

The purpose of this study was to assess the levels of lung and gastric tidal volumes paramedics achieve when performing ventilation with bag-valve-mask, laryngeal mask, and Combitube. Twenty paramedics performed ventilation with a bag-valve mask, laryngeal mask, and Combitube in a bench model simulating an unintubated cardiorespiratory arrest patient. Lung and gastric tidal volumes and lung and gastric peak airway pressures were subsequently measured. The results showed that mean +/- SEM lung tidal volumes were significantly higher with the laryngeal mask and Combitube compared to the bag-valve-mask (701 +/- 264 vs. 742 +/- 311 vs. 353 +/- 110 mL, respectively). No gastric inflation occurred with the Combitube; gastric inflation was significantly lower with the laryngeal mask compared to the bag-valve-mask (25 +/- 15 vs. 230 +/- 25 mL, respectively). Both the laryngeal mask and Combitube proved to be valid alternatives for bag-valve-mask ventilation in our bench model simulating an unintubated patient with cardiorespiratory arrest.

Smaller tidal volumes with room-air are not sufficient to ensure adequate oxygenation during bag-valve-mask ventilation

The European Resuscitation Council has recommended decreasing tidal volume during basic life support ventilation from 800 to 1200 ml, as recommended by the American Heart Association, to 500 ml in order to minimise stomach inflation. However, if oxygen is not available at the scene of an emergency, and small tidal volumes are given during basic life support ventilation with a paediatric self-inflatable bag and room-air (21% oxygen), insufficient oxygenation and/or inadequate ventilation may result. When apnoea occurred after induction of anaesthesia, 40 patients were randomly allocated to room-air ventilation with either an adult (maximum volume, 1500 ml) or paediatric (maximum volume, 700 ml) self-inflatable bag for 5 min before intubation. When using an adult (n=20) versus paediatric (n=20) self-inflatable bag, mean +/-SEM tidal volumes and tidal volumes per kilogram were significantly (P<0.0001) larger (719+/-22 vs. 455+/-23 ml and 10.5+/-0.4 vs. 6.2+/-0.4 ml kg(-1), respectively). Compared with an adult self-inflatable bag, bag-valve-mask ventilation with room-air using a paediatric self-inflatable bag resulted in significantly (P<0.01) lower paO(2) values (73+/-4 vs. 87+/-4 mmHg), but comparable carbon dioxide elimination (40+/-2 vs. 37+/-1 mmHg; NS). In conclusion, our results indicate that smaller tidal volumes of approximately 6 ml kg(-1) ( approximately 500 ml) given with a paediatric self-inflatable bag and room-air maintain adequate carbon dioxide elimination, but do not result in sufficient oxygenation during bag-valve-mask ventilation. Thus, if small (6 ml kg(-1)) tidal volumes are being used during bag-valve-mask ventilation, additional oxygen is necessary. Accordingly, when additional oxygen during bag-valve-mask ventilation is not available, only large tidal volumes of approximately 11 ml kg(-1) were able to maintain both sufficient oxygenation and carbon dioxide elimination.

Optimisation of tidal volumes given with self-inflatable bags without additional oxygen

The European Resuscitation Council has recommended smaller tidal volumes of 500 ml during basic life support ventilation in order to minimise gastric inflation. One method of delivering these tidal volumes may be to use paediatric instead of adult self-inflatable bags; however, we have demonstrated in other studies that only 350 ml may be delivered, using this technique. The reduced risk of gastric inflation was offset by oxygenation problems, rendering the strategy of attempting to deliver tidal volumes of 500 ml with a paediatric self-inflatable bag questionable, at least when using room-air. In this report, we assessed the effects of a self-inflatable bag with a size between the maximum size of a paediatric (700 ml) and an adult (1500 ml) self-inflatable bag on respiratory variables and blood gases during bag-valve-mask ventilation. After induction of anaesthesia, 50 patients were block-randomised into two groups of 25 each. They were ventilated with room-air with either an adult (maximum volume, 1500 ml) or a newly developed medium-size (maximum volume, 1100 ml; Dräger, Lübeck, Germany) self-inflatable bag for 5 min before intubation. When compared with the adult self-inflatable bag, the medium-size bag resulted in significantly lower exhaled tidal volumes and tidal volumes per kg bodyweight (624 + 24 versus 738 +/- 20 ml, and 8.5 +/- 0.3 versus 10.7 +/- 0.3 ml kg(-1), respectively; P < 0.001), oxygen saturation (95 +/- 0.4 versus 96 +/- 0.3%; P < 0.05), and partial pressure of oxygen (78 +/- 3 versus 87 +/- 3 mmHg; P < 0.05). Carbon dioxide levels were comparable (37 +/- 1 versus 37 +/- 1 mmHg). Our results indicate that smaller tidal volumes of about 8 ml x kg(-1) (approximately 600 ml), given with a new medium-size self-inflatable bag and room-air, maintained adequate carbon dioxide elimination and oxygenation during bag-valve-mask ventilation. Accordingly, the new medium-size self-inflatable bag may combine both adequate ventilatory support and reduced risk of gastric inflation during bag-valve-mask ventilation.

Smaller tidal volumes during cardiopulmonary resuscitation: comparison of adult and paediatric self-inflatable bags with three different ventilatory devices

Gastric inflation and subsequent regurgitation of stomach contents is a major hazard of bag-valve-face mask ventilation during the basic life support phase of cardiopulmonary resuscitation (CPR). Recent investigations suggested that use of a paediatric self-inflating bag may reduce stomach inflation while ensuring sufficient lung ventilation. The purpose of our study was to examine whether use of a paediatric self-inflating bag in association with laryngeal mask airway, combitube, and bag-valve-face mask may provide adequate lung ventilation, while reducing the risk of gastric inflation in a bench model simulating the initial phase of CPR. Sixteen intensive care unit registered nurses volunteered for our study. Use of a paediatric versus adult self-inflating bag resulted in a significantly (P < 0.01) lower mean (+/- S.D.) tidal lung volume with both the laryngeal mask airway and combitube (laryngeal mask airway 349 +/- 149 ml versus 725 +/- 266 ml, combitube 389 +/- 113 ml versus 1061 +/- 451 ml). Lung tidal volumes were below the European Resuscitation Council recommendation with both self-inflatable bags in the bag-valve-face mask group (paediatric versus adult self-inflatable bag 256 +/- 77 ml versus 334 +/- 125 ml). Esophageal tidal volumes were significantly (P < 0.05) lower using the paediatric self-inflatable bag in the bag-valve-face mask group; almost no gastric inflation occurred with the laryngeal mask airway, and none with the combitube. In conclusion, use of the paediatric self-inflating bag may reduce gastric inflation, but measured lung tidal volumes are below the European Resuscitation Council recommendation when used with either, the laryngeal mask airway, combitube, or bag-valve-face mask.

A comparison of the cuffed oropharyngeal airway (COPA) with the laryngeal mask airway (LMA) during manually controlled positive pressure ventilation

STUDY OBJECTIVE

To examine the cuffed oropharyngeal airway (COPA) during positive pressure ventilation (PPV) and to compare its reliability and efficacy with the laryngeal mask airway (LMA).

DESIGN

Prospective, randomized, controlled trial.

SETTING

University Hospital.

PATIENTS

60 adult ASA physical status I and II patients scheduled for urologic surgery.

INTERVENTIONS

Patients were randomly assigned to be ventilated with a COPA (n = 33) or a LMA (n = 27) during a standardized anesthetic procedure. Following preoxygenation and induction with alfentanil and propofol, the respective airways were inserted. Patients were ventilated manually with the reservoir bag of the anesthesia respirator. Inspiratory airway pressure was limited to 20 cm H2O, and the target tidal volume was 7 ml/kg. Respiratory rate was adjusted to achieve an end-tidal pressure of carbon dioxide of 35 mmHg. Anesthesia was maintained with propofol, nitrous oxide in oxygen, and alfentanil, as appropriate.

MEASUREMENTS AND MAIN RESULTS

We evaluated ease of insertion (nominal scale: easy, moderate, difficult, or impossible) and recorded the number of maneuvers performed during insertion until an airtight seal of the airway was achieved. Reliability for "hands free" ventilation--defined as ventilation without the need to further augment the position of the airway device manually--was determined (nominal scale: adequate ventilation, adequate ventilation with manual assistance, and inadequate ventilation leading to airway change). Ventilation and oxygenation parameters were derived from the anesthesia respirator and a capillary blood gas sample, respectively. The incidence of laryngopharyngeal discomfort and the amount of salivation were assessed by nominal scales. The COPA was easier to insert than the LMA (p < 0.001), but more positional maneuvers (p < 0.001) were necessary with this device. "Hands free" ventilation was achieved less often with the COPA (p < 0.02). Ventilation and oxygenation were comparable with both devices. The COPA was associated with less salivation (p < 0.01) and laryngopharyngeal discomfort (p < 0.05) than the LMA.

CONCLUSION

Although effective ventilation can be accomplished with both devices, the LMA is more reliable for "hands free" ventilation than the COPA. The lower incidence of laryngopharyngeal discomfort and salivation with the COPA may be beneficial for patients at risk for developing laryngospasm.

Airway management during cardiopulmonary resuscitation--a comparative study of bag-valve-mask, laryngeal mask airway and combitube in a bench model

Gastric inflation and subsequent regurgitation are a potential risk of ventilation during cardiopulmonary resuscitation (CPR). In respect of recent investigations, principal respiratory components such as respiratory system compliance, resistance and lower esophageal sphincter pressure were adapted according to CPR situations. The purpose of our study was to assess lung ventilation and gastric inflation when performing ventilation with bag-valve-mask, laryngeal mask airway, and combitube in a bench model simulating an unintubated cardiac arrest patient. Twenty-one student nurses, without any experience in basic life support measures, ventilated the bench model with all three devices. Mean ( +/- S.D.) gastric inflation with the laryngeal mask airway (seven cases) was significantly lower than with the bag-valve-mask (0.6 +/- 0.8 vs 3.0 +/- 2.11 min(-1), P < 0.01). There was no gastric inflation when ventilation was performed with the combitube. Only seven of 21 volunteers exceeded 1-min lung volumes of > 5 1 when using the bag-valve-mask, whereas mean (+/-S.D.) 1-min lung volumes with both laryngeal mask airway and combitube were significantly higher (laryngeal mask airway 15.0+/-6.61, combitube 16.6 +/- 6.81 vs bag-valve-mask 4.8 +/- 2.71, P < 0.01). The time for insertion was significantly faster with both bag-valve-mask and laryngeal mask airway compared with the combitube (median: bag valve mask 22 s, laryngeal mask airway 37 s vs combitube 70 s, P < 0.01). This may tip the scales towards using the laryngeal mask airway during basic life support airway management. In conclusion, our data suggests that both laryngeal mask airway and combitube may be appropriate alternatives for airway management in the first few minutes of CPR.

Cyclophosphamide-induced aberrations of chromosome pairing in pachytene oocytes

The aim of this study was to characterise damage to synaptonemal complexes in oocytes following cyclophosphamide exposure. Pregnant mice were treated with three different doses of cyclophosphamide (10, 30 and 50 mg/kg body weight) at day 13 of gestation, when oogonia and very early meiotic cells in the female fetuses are found. Primary oocytes were analysed by light- and electron microscopy at gestational day 17 to reveal effects of the alkylating agent on the chromosomal pairing behaviour. Our pachytene analysis demonstrated that the fraction of cells with lesions of synaptonemal complexes, partial asynapsis and desynaptic bivalents were significantly increased over the levels in the control group. The frequency of alterations was similar at doses of 30 and 50 mg/kg. In addition, a significant increase in frequency of univalents over the base level became evident, showing the highest incidence on a dose of 50 mg/kg.