Difficult airway management patterns among attending anaesthetists practising in Israel.

BACKGROUND AND OBJECTIVE: In recent years, a large number of airway devices have been introduced into clinical practice as adjuncts to the management of the difficult airway. The purpose of this study was to evaluate the practices of Israeli anaesthetists in specific clinical situations and their familiarity with the use of a variety of airway devices and techniques. METHODS: A survey developed in our institution was sent to 300 attending anaesthetists representing all board-certified anaesthetists practising in Israel. RESULTS: Of the 153 respondents, 75% belonged to university hospitals. Ninety-six percent were skilled with laryngeal mask airways and 73% with fibreoptics. Seventy percent preferred regional anaesthesia with anticipated difficult intubation, continuation of anaesthesia with a laryngeal mask with failed intubation and a laryngeal mask for impossible mask ventilation. For the airway scenarios, awake fibreoptic, awake direct laryngoscopy, intubation under inhalation anaesthesia and tracheostomy were shared equally. CONCLUSIONS: There is a high degree of adherence by Israeli anaesthetists to the American Society of Anesthesiologists' difficult airway algorithm. Current airway management practice patterns in Israel are presented.

Peripartum general anasthesia without tracheal intubation: incidence of aspiration pneumonia.

This study estimated the incidence of pulmonary aspiration during general anasthesia for obstetric procedures performed in the peripartum period (Caesarean sections were not studied). The records of 1870 patients anasthetised without tracheal intubation were reviewed retrospectively. The diagnosis of aspiration was based on the anasthetist's written remarks and the postoperative course. Eighty per cent of patients received ketamine and a benzodiazepine, and the remaining 20% received methohexital or thiopental and fentanyl. No cricoid pressure or tracheal intubation was performed. A single case of mild aspiration was detected in a woman anasthetised with methohexital (an incidence of 0.053%). These results suggest that the risk of aspiration during general anasthesia without tracheal intubation, during and immediately after delivery, may not be higher in obstetric patients in the peripartum period, as has been reported previously.

Events which will influence intensive care units in future. A Delphi study.

OBJECTIVE: To find out and analyse the events which are expected to influence the future of Intensive Care Units (ICU). DESIGN: Three round Delphi study. SETTING: In a first preparation round 9 events were defined. In the two rating rounds an international panel of 60 experts heads of ICUs) estimated the time when the events may come true and whether they are desired or not. RESULTS: Computer tools are desired and expected in the near future (before the year 2000) for audit, quality assurance, record keeping and telecommunication; complex closed loops and nursing robots will not be used in clinical routine before 2005, they are not desired.

[Combined intrapleural and low epidural anesthesia for upper abdominal surgery].

Intrapleural administration of local anesthetics to achieve postoperative analgesia was recently described by Kvalheim and Reiestad. It has been stated that the intrapleural technique provides analgesia, but not surgical anesthesia. However, this method has been used recently for anesthesia during minor surgical procedures. We describe the use of combined, bilateral intrapleural and low epidural anesthesia in a woman with severe impairment of cardiopulmonary function who underwent combined splenectomy and cholecystectomy.

System ergonomic analysis of the morning ward round in an intensive care unit.

OBJECTIVE: Our objective was to find out what is discussed during a bedside morning ward round (MWR), whether there are any weak points, and if a standard work process structure can be recommended. METHODS: An intensive care unit (ICU) consultant recorded in a predefined form the topics that were discussed in 225 bedside discussions. RESULTS: The median length of discussions was 5 min. In more than 60% of the discussions, items were considered related to the respiratory, neurological, and cardiovascular systems, as well as to surgical and nursing problems. Specific variables relating to organ system conditions were seldom used (e.g., inspired O2 concentration, 35%; temperature, 28%; ventilation mode, 25%). We recorded two interruptions per MWR; only 17% of them were related to urgent decisions. Information that could not be found in the patient's file usually concerned microbiology findings (10%) or surgical procedures (6%). CONCLUSIONS: We recommend the following structure: (1) Addressing the patient by saying "hello"; (2) presentation of information related to case history, acute status (findings and strategy) (including the function of the main organ systems), infection status, and nursing problems; (3) patient-related discussion; and (4) discussion of general treatment rules, triggered by individual patient condition.

Information transfer in high dependency environments: an ergonomic analysis.

We have studied the information flow in HDE (with special focus on the information transfer process) using data provided by a group of experienced health care professionals. A model of the information flow in HDE was built up. It postulates the existence of quanta of information (due to the artificial fragmentation of the information flow produced by the clinical working processes: organization in shifts, demand of simultaneous activities from different staff members, etc.). This fragmentation is described by using the so-called Clinical Information Process Units (CIPUs), which correspond to patient care activities going on in parallely and serially linked blocks, performed by the staff in the specific environments. Due to a transfer in responsibility over the patient the CIPUs are linked by information transfer events which are described using transfer modules (TraMs). We exemplified 32 CIPUs related to the clinical environments (PreOp, Surgery, Recovery Intensive Care, Ward, Diagnostics, Outpatient) and the health care professional groups (Anesthesiologist/Intensivist, Surgeon, Nurse, Physician, Diagnostic Physician, Physical Therapist). A matrix was established providing the transfer situations among the CIPUs enabling a systematic classification of the TraMs. The contents of the TraMs are built up of information link elements, which are assembled according to the specific settings of the transfer situation given by the emitter, receiver and purpose. In summary we modelled the process of information transfer in HDE through CIPUs, TraMs and information links in a way, which may be useful to design information technology applications or to reorganize the information management in HDE.

Data quality of bedside monitoring in an intensive care unit.

Computerized record keeping promises complete, accurate and legible documentation. Reliable measurements are a prerequisite to fulfill these expectations. We analyzed the physiological variables provided by bedside monitoring devices in 657 bedside visits performed by an experienced Intensive Care nurse during 75 Intensive Care rounds. We registered which variables were displayed. If a variable was displayed, we assessed whether it could be used for documentation or should be rejected. If a value was rejected the reason was registered as: the measurement was not intended (superfluous display), the current clinical situation did not allow proper measurement, or other reasons. Basic variables (vital signs and respiration related variables) were displayed in more then 90%, specific variables (e.g. intracranial pressure) were displayed in less than 50% of the situations. Displayed variables were superfluous on an average of 11% because measurement was not intended. Variables like heart rate, temperature, airway pressure, minute volume of ventilation, arrhythmia, pulmonary arterial pressure, non-invasive blood pressure, and intracranial pressure provide high quality measured values (acceptance of more than 90%). Invasive arterial pressure, central venous pressure, respiration rate and oxygen saturation (via pulse oximetry) provided lower quality values with a rejection rate higher than 10%. Inappropriate sensor technology to match the clinical environment seems to be the root cause. In future the request for automatic documentation will increase. In order to avoid additional staff workload and to ensure reliable documentation, sensor technology especially related to respiration rate, blood pressure measurements, and pulse oximetry should be improved.

Lessons learned while building an integrated ICU workstation.

The project LUCY (Linked Ulm Care sYstem) is described. The goal of this project was to build a research workstation in an Intensive Care Unit which enables evaluation of data/information processing and presentation concepts. Also evaluation of new devices and functions considering not only one device but the workplace as an entirety was an aim of the project. We describe the complete process of building from the stage of design until its testing in clinical routine. LUCY includes a patient monitor, a ventilator, 4 infusion pumps and 8 syringe pumps. All devices are connected to a preprocessing computer via serial interfaces. A high performance graphic workstation is used for central display of physiological and therapeutic variables. A versatile user interface provides touch screen, keyboard and mouse interaction. For fluid administration a bar code based control and documentation facility was included. While our scheduled development efforts were below 4 man-years, the overall man-power needed until the first routine test amounts to 8 man-years. Costs of devices and software sum up to 160,000 US$. First experiences in clinical routine show good general acceptance of the workplace concept. Analysing the recorded data we found 90% of the items to be redundant: individual filtering algorithms are necessary for each of nowaday's devices. The flexibility of the system concerning the implementation of new features is far from our expectations. Technical maintenance of the system during clinical operation requires continuous effort which we cannot afford in the current situation.

Decision making in high dependency environments--can we learn from modern industrial management models?

Increasing complexity and increased restraints affect the task of patient management in High Dependency Environments, which has become intricate and difficult. Medical knowledge alone is not enough any longer for proper patient care. Management ability and facilities are required. Current medical knowledge should be expanded by management methods and techniques. By looking at management models in the industry, we found striking similarities between the industrial management situation and clinical patient management. Both systems share complexity in structure, complexity in interaction and evolutionary character. Clinical patient management can be compared with a navigation process. The patient is steered by a control system, and course information is given by control dimensions. Clinical patient management becomes a succession of steering activities influenced by the surrounding systems. This system can be structured in three interacting layers: an operational level, in which information is collected and actions executed; a strategic level in which strategies based on goal-oriented mental anticipation of a probabilistic system are formulated; and a normative level at which principles and norms are defined. It is possible then, to define the tools which have to be developed and implemented to improve clinical management capabilities. At the operational level these tools are addressed to improve clinical decision making by providing information in an ergonomical way. They include artifact elimination, data reduction, increase in meaningful information and unwanted data filtering. At the strategic level, tools to check the feasibility of the applied strategies have to be developed, such as: ideal patient course plots and increased training in strategic thinking.(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical information process units (CIPUs) - a system ergonomic approach to medical information systems.

This article constitutes an introduction to the basic tools necessary to understand Systems Ergonomics applied to the development of clinical systems. A basic description of clinical patient care in the system ergonomics language is provided, and the current situation found in hospital information management is criticized from an ergonomic point of view. We have laid out a model of the information flow in the clinical environment, which breaks the complex process of patient care in clearly defined elements: the Clinical Information Process Units. Presented here as an example of the application of Systems Ergonomics to the clinical working processes, the Clinical Information Process Units constitute the central element in the system ergonomic model of the information flow in the clinical environment.

Ergonomics applied to anaesthesia record keeping.

For almost 100 years, the anaesthesia record has been the sole information tool trying to fulfill an ample catalogue of functions related to the anaesthesia information processes. Automated anaesthetic record systems have evolved around data being available online, as an imitation of the handwritten record. None has developed an information tool capable of an efficient utilization of the wide range of resources provided by modern technology to fulfill the information requirements of the anaesthetic environment. We used a system ergonomic analysis trying to find the best solutions. As a result of it we drafted an Anaesthesia Information Concept (AIC) in which the complexity of data & information (D&I) processes is broken down to modules called Clinical Information Process Units (CIPUs). A CIPU is mainly defined by the responsibility of a staff member and focuses on the basic system patient, staff and machine (all devices). The internal functions of a CIPU are treatment control and medicolegal documentation. The external functions are fulfilled by transferring required sets of D&I for subsequent treatment control (next CIPU), audit, quality control, cost calculation, etc. Using such an approach, an Anaesthesia Information Concept (AIC) can be realized by a wide range of modular and hybrid systems (combination of different tools such as paper records, computers, etc), as opposed to universal and single automated documentation systems, which up to now have failed to fulfill the information demands of the anaesthetic environment.

Thionyl-chloride-induced lung injury and bronchiolitis obliterans.

Thionyl-chloride (TCl) is used in the manufacture of lithium batteries, producing SO2 and HCl fumes on contact with water. We report two cases of accidental TCl exposure resulting in lung injury that may vary from a relatively mild and reversible interstitial lung disease to a severe form of bronchiolitis obliterans causing, after a latent period, an acute/chronic respiratory failure as well as other complications (spontaneous pneumothorax and bronchopleural fistula), previously unreported in TCl fume inhalation.

Pulse oximetry from the nasal septum.

STUDY OBJECTIVE: To evaluate the accuracy of the nasal septum site for pulse oximetry measurement of arterial oxyhemoglobin saturation (SpO2) in hypothermic patients. DESIGN: Prospective study. SETTING: Operating theater of a public hospital. PATIENTS: Fourteen hypothermic (temperature 34.6 degrees C to 36 degrees C) patients (eight males and six females) undergoing a major surgical abdominal procedure. INTERVENTIONS: Fifty estimations of SpO2 were simultaneously made by a flex sensor probe applied at the nasal septum site and by a finger sensor probe using a pulse oximeter. The results were compared with arterial oxygen saturation (SaO2) as measured by arterial blood gas sampling. MEASUREMENTS AND MAIN RESULTS: In 18% of the estimations, the finger probe produced unmeasurable results. The nasal septum probe did not produce any unmeasurable results (p = 0.0055). In the remaining 41 estimations, a comparison of the measurements from the nasal septum versus the controls showed a mean difference of 0.15 and a limit of agreement of -0.106 to +0.398. A comparison difference of 2.27 and a limit of agreement of 1.986 to 2.551. CONCLUSION: Monitoring SpO2 at the nasal septum site is more reliable than monitoring it at the finger site in hypothermic patients.

Impaired water homeostasis following mixed carbamazepine and phenobarbital overdose.

Both carbamazepine and phenobarbital are known to have antidiuretic properties when administered chronically. We describe a case of acute impairment of body water homeostasis following mixed drug overdose with carbamazepine and phenobarbital. Serum carbamazepine concentrations correlated with alternating states of diuresis and antidiuresis. We recommend close monitoring of fluid and electrolyte status in carbamazepine overdose.

Conservative approach to massive haemoperitoneum of ovarian origin during anticoagulant therapy.

Recurrent massive haemoperitoneum of ovarian origin during anticoagulant therapy in a patient with mitral valve prosthesis is described. The patient was treated conservatively on both occasions. The authors suggest that a trial of conservative approach may be considered in such patients.

Schizophrenia and fatal self-induced water intoxication with appropriately-diluted urine.

A 31-year-old woman with untreated chronic schizophrenia developed extreme polydipsia which rapidly led to coma and death due to cerebral edema. Hyponatremia (120 mEq/liter) and serum hypo-osmolality (260 mOsm/kg) were associated with marked polyuria (up to 1850 ml/hour) and appropriately low urinary osmolality (90 mOsm/kg) which responded to treatment. This case and few qualifying previous reports which are reviewed support the possibility that pure self-induced water intoxication with no major contribution of inadequate release of antidiuretic hormone may occur, and that extreme polydipsia can sometimes overwhelm normal renal diluting capacity in psychotic patients.

Adult respiratory distress syndrome: roles of leukotriene C4 and platelet activating factor.

The relationship between leukotriene C4 (LTC4), platelet activating factor (PAF), and adult respiratory distress syndrome (ARDS) was studied in nine patients and 84 control subjects. A leukocyte adherence inhibition (LAI) assay induced by each of the ligands was used to monitor the subjects for 3 consecutive days or until clinical recovery was noted. LAI was considered to be positive if the nonadherence index (NAI) was greater than 30 for LTC4 or greater than 20 for PAF. LAI was negative in all healthy subjects using both ligands. LTC4-induced LAI was positive in all nine ARDS patients and reverted to negative after recovery from the syndrome, while three (33.3%) of nine patients responded to PAF. In contrast, of the 84 control subjects, LAI was induced by LTC4 in only three (3.3%) and by PAF in five (5.9%). The mean NAI (52.2 +/- 18) of LTC4-induced LAI in ARDS patients was significantly (p less than .05) higher when compared with the control group (-5 +/- 6.4), whereas that of PAF-induced LAI was less than 20 in both groups, indicating that LTC4 is a more specific ligand than PAF. All three patients in whom ARDS was caused by sepsis responded to both LTC4 and PAF, but results of specific receptor-antagonist experiments indicated that each compound acted independently. The mean NAI for LTC4 (58.5 +/- 10) and PAF (49.1 +/- 12) in patients with septic ARDS were significantly (p less than .05) higher when compared with those of patients with sepsis alone (0.5 +/- 9.9 and 4.4 +/- 17, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Minicricothyrotomy for tracheobronchial toilet.

Thirty-six patients underwent percutaneous cannulation of the cricothyroid membrane, using a small endotracheal tube, for the purpose of repeated suction of secretions from the tracheobronchial tree. The duration of cannulation ranged from 4 to 62 days (average, 12 days). Twenty-eight patients were followed up for a maximum of 3.5 years (mean, 20 months). There were no immediate or delayed postoperative complications. Subglottic stenosis did not occur in any of the patients. Minicricothyrotomy is a relatively safe and simple and efficient technique for tracheobronchial toilet in patients with chronic lung disease and in the postoperative period.