[Complications and late sequelae after nasotracheal intubation]. / Komplikationer og senfølger efter nasotrakeal intubation.

A total of 379 patients admitted to the Intensive Care Unit (ICU) for mechanical ventilation were prospectively investigated for lesions of the nose, nasal cavity, ears and larynx during and after nasotracheal intubation. One to two years later, the surviving patients were questioned to investigate late persisting sequelae. During intubation and up to five days following extubation, inflammatory changes and ulceration of the nostrils or nasal septum were found in respectively 76 (20%) and 110 (29%) patients. There were bleedings from the nasal cavity in 67 (19%) and fractures of the conchae in 40 patients (11%). Hoarseness was noted in 135 patients (42%). Inflammatory changes and ulcerations of the nostril and nasal septum were correlated to the duration of intubation. Among the 281 patients included in the follow-up study, 100 (35%) had symptoms from the nose and nasal cavity. Sixty-five (24%) had symptoms related to the ears, 56 (20%) to the maxillary sinus, 81 (29%) to the voice and 90 (32%) to the throat. Increasing duration of intubation was found to be correlated to persisting symptoms from the larynx. Former ulcerations of the nose were associated with a tendency toward nasal bleeding. To avoid as many complications as possible from the nose and nasal cavity, we recommend orotracheal intubation. As late sequelae from the larynx increase with the duration of intubation, perhaps tracheostomy should be performed earlier than is general practice today, but that has to be proven in forthcoming studies.

[Fasting times, ventricular aspiration and use of antacids and H2 blockaders at Danish departments of anesthesiology]. / Fastetider, ventrikelaspiration samt brug af antacida og H2-blokkere på danske anaestesiafdelinger.

In a questionnaire sent to 58 anaesthetic departments in Denmark (1992/93), we assessed fasting guidelines, preoperative gastric emptying and the use of pharmacological aspiration prophylaxis. Replies were obtained from 51 departments (88%). Most departments (90%) fast adults for at least six hours prior to elective surgery. However, 14 departments (27%) plan to change their guidelines to allow the intake of clear liquid on the day of surgery. Eighteen departments (35%) hardly ever use preoperative gastric emptying prior to emergency surgery. The other departments differ as to when gastric emptying should be performed. Only few departments (25%) employ pharmacological prophylaxis.

[Aspiration pneumonia]. / Aspirationspneumoni.

Pulmonary aspiration of stomach contents is a common clinical problem. Symptoms and consequences depend on the aspired volume, the pH and the content of food particles and bacteria. There are two phases following an aspiration of stomach contents into the lungs. The first phase is nonspecific and begins a few minutes after the aspiration. This phase is due to the chemical injury. The second phase is an inflammatory reaction. The reaction is haemorrhagic, granulocytic and necrotizing when the aspirate is acid (pH < 2.5). The presence of food particles causes granulomas. The immunological reactions are biphasic as well. The bacterial infection is mainly secondary to the chemical inflammation and occurs with an infection rate of 25-50%. The optimum management is symptomatic and should entail immediate endotracheal suction, aggressive ventilatory support with supplemental oxygen, CPAP or PEEP if indicated by clinical assessment and blood gas measurements, adequate fluid replacement and antibiotics if there is evidence of bacterial infection.

Complications and late sequelae following nasotracheal intubation.

A total of 379 patients admitted to the ICU for mechanical ventilation were prospectively investigated for lesions on the nose, nasal cavity, ears and larynx during and after nasotracheal intubation. One to two years later, the surviving patients were questioned to investigate late persisting sequelae. During intubation and up to 5 days following extubation, inflammatory changes and ulceration of the nostrils or nasal septum were found in 76 (20%) and 110 patients (29%), respectively. There were bleedings from the nasal cavity in 67 (19%) and fractures of the conchae in 40 patients (11%). Hoarseness was noted in 135 patients (42%). Inflammatory changes and ulcerations of the nostril and nasal septum were correlated to the duration of intubation. Among the 281 patients included in the follow-up study, 100 (35%) had symptoms from the nose and nasal cavity. Sixty-five (24%) had symptoms related to the ears, 56 (20%) to the maxillary sinus, 81 (29%) to the voice and 90 (32%) to the throat. Increasing duration of intubation was found to be correlated to persisting symptoms from the larynx. Former ulcerations of the nose were associated with a tendency to nasal bleeding. To avoid as many complications as possible from the nose and nasal cavity, we recommend orotracheal intubation. As late sequelae from the larynx increase with the duration of intubation, perhaps tracheostomy should be performed earlier than is general practice today, but that has to be proven in forthcoming studies.

The effects of general anaesthesia on antroduodenal motility, gastric pH and gastric emptying in man.

This survey was based on five recently published papers. The aims of the studies were to to investigate the effect of general anaesthesia on antroduodenal motility, gastric pH and gastric emptying. Antroduodenal motility was measured by manometry, gastric pH by a stomach microelectrode and gastric emptying rate using paracetamol absorption as an index. Two studies deal with antroduodenal motility during basal conditions and after administration of paracetamol and diazepam in 11 healthy volunteers. Three studies deal with the effects of 4 different methods of general anaesthesia on antroduodenal motility, gastric pH and gastric emptying rate in 43 patients undergoing orthopedic or plastic surgery not involving the abdomen having four different methods of general anaesthesia. In the healthy volunteers a close connection between antral activity and gastric emptying rate was found. Paracetamol had no effects on gastric pH. The changes in motility (a shortening of phase III and a decline in the incidence of antral phase III activity) were minor and ascribed to diurnal variations and by a possible stimulation of antral activity by the positioning of the manometric tube. It was found that no paracetamol was absorbed in the quiescent phase I, irrespective of its duration, and that the absorption rate of paracetamol correlated with the duration of phase II and the occurrence of antral activity during phases II and III. The effects of premedication with diazepam on antroduodenal motility, gastric pH and gastric emptying rate was investigated in the same healthy volunteers prior to the patient studies. Also in this study a correlation between antral activity and gastric emptying rate was found. Furthermore, it was observed that some volunteers had fast gastric emptying rate, indicated by fast absorption of paracetamol, the first study day and slow the second. It seemed that any intra- or interindividual variation in gastric emptying rate arises from individual variations in antroduodenal motility. Diazepam tended to increase gastric emptying rate by enhancing the amplitudes of antral contractions and the motility index during phase II and pH of the gastric juice increased. Gastroduodenal motility was found to be normal in patients awaiting elective orthopedic or plastic surgery when premedicated with diazepam. pH of the gastric contents was not different from the findings in volunteers after administration of diazepam. All methods of general anaesthesia reduced the duration of the interdigestive motility complex, mainly by a reduction of phase II. General anaesthesia with halothane and enflurane depressed antral motility.(ABSTRACT TRUNCATED AT 400 WORDS)

[Perioperative treatment of diabetics]. / Perioperativ diabetesbehandling.

The metabolic changes in connection with fasting, anaesthesia and surgery in diabetic patients and non-diabetic patients are reviewed. Various perioperative forms of treatment are described. The forms of treatment most commonly employed are infusion of glucose-insulin-potassium (GIK) and subcutaneous administration of insulin followed by infusion of glucose (KON). The more intensive GIK regime provides the diabetic patient with a biochemical regulation which resembles that found in non-diabetics. It has not been proved whether this marginal regulation influences the well-being, morbidity or mortality of the patients. In critically ill patients or patients with concurrent diseases, the GIK regime is recommended as this provides optimal regulation of the diabetes. In the remaining patients, local conditions will influence the choice of form of treatment.

The effect of nasotracheal intubation on the paranasal sinuses. A prospective study of 434 intensive care patients.

A total of 434 patients admitted to the intensive care unit for mechanical ventilation were followed prospectively to investigate the influence of a nasotracheal tube on the paranasal sinuses. Twenty-five patients died before the examination was completed. The rest were examined for clinical symptoms of sinusitis. If sinusitis was suspected or the patients were intubated for 5 days or more, an x-ray of the sinuses was performed. In patients intubated for less than 5 days (N = 357), sinusitis was clinically suspected in three, but radiographically verified in only one. In patients intubated for 5 days or more (N = 47), 23 (49%) had affection of the paranasal sinuses. Patients needing a nasotracheal tube should be examined for sinusitis if they are intubated for more than 5 days or if unexplained fever, sepsis or purulent nasal secretion develops. If the suspicion is confirmed, the nasotracheal tube should be removed.

Is minitracheotomy a simple and safe procedure? A prospective investigation in the intensive care unit.

Patients with imminent respiratory failure due to sputum retention were assessed for minitracheotomy (MT). MT was considered potentially useful in 79 patients but only attempted in 73, 54 men and 19 women, aged 23-81 years (median 65 years). Insertion of the cannula failed in 4 cases. Sputum retention and atelectasis were successfully treated in 87% (N = 60). Treatment by MT in medical and neurological patients seems as effective as in surgical patients (success rate 81% versus 90%). The frequency of complications was 16%. Most complications were insignificant and occurred during cannulation, but a few severe complications were seen. To minimize the number of these it is essential that MT is done only by doctors who are familiar with the procedure. MT can be recommended for treatment of sputum retention and atelectasis in surgical and medical/neurological intensive care patients with preserved cough function.

[Sinusitis caused by nasotracheal intubation]. / Sinuitis som følge af nasotrakeal intubation.

Sinusitis following nasotracheal intubation (NTI) is an almost overlooked complication. The pathogenesis is believed to be development of oedema of the nasal mucosa due to irritation by the tube in the nasal cavity. The size of the tube is probably not important, whereas the duration of intubation is of major importance. The infection is often caused by Gram-negative microorganisms. The frequency is found to be 0.3% in short term intubation (less than 5 days) and 40.4% in long term intubation (greater than 5 days). In neurosurgical patients treated with NTI sinusitis is found in 52% and 100% of the patients. In adults the indications for prolonged NTI instead of orotracheal intubation and early tracheostomy should be considered carefully. If fever or sepsis develops in patients treated with NTI, investigations for sinusitis should be included in the search for focus. When sinusitis has developed, the tube should be removed, and the patient tracheostomised. If this treatment fails, surgical drainage should be performed.

Effects of general anaesthesia with enflurane on antroduodenal motility, pH and gastric emptying rate in man.

Antroduodenal motility, pH and gastric emptying rate were investigated before, during and after general anaesthesia with enflurane in 11 patients undergoing elective surgery not involving the abdomen. Motility was measured by manometry and the gastric emptying rate by the rate of paracetamol absorption. During anaesthesia gastric emptying rate was delayed in nine patients. General anaesthesia with enflurane nearly abolished the motility in the antrum. The duration of successive interdigestive motor complexes was reduced (P less than 0.001) mainly be a reduction in Phase II (P less than 0.01). The frequency of contractions was unchanged in the duodenum during Phase II and decreased during Phase III (P less than 0.01). The amplitudes of contractions were unchanged in the proximal part of the duodenum and decreased in the distal part (P less than 0.01). General anaesthesia with enflurane increased the gastric pH per- and post-operatively (P less than 0.01). Motility in the antrum was rapidly regained in the recovery period. General anaesthesia with enflurane seems to delay gastric emptying rate by affecting the motility in the gastric antrum. The acidity of the stomach contents is reduced.

Antroduodenal motility, pH and gastric emptying during balanced anaesthesia: comparison of pethidine and fentanyl.

In a randomized study of 22 patients, antroduodenal motility, pH and gastric emptying rate were measured during barbiturate anaesthesia with pethidine or fentanyl. Motility was measured by manometry and gastric emptying rate by the paracetamol absorption test. Anaesthesia reduced the duration of the interdigestive motility complexes with both analgesics (P less than 0.001), mainly by a shortening of phase II (P less than 0.01). The duration of phase II and III were shorter with pethidine, and pethidine reduced both the frequency and amplitudes of antral contractions during phase II (P less than 0.01). Fentanyl affected only the amplitudes. The phase III variables assessed were unchanged, apart from a decrease in the velocity of propagation of the motility complexes with pethidine (P less than 0.01). The gastric pH increased in both groups during and after operation (P less than 0.01). Gastric emptying rate was normal in 82% with fentanyl and in 60% with pethidine. Motility in the recovery period approached, but did not reach, preoperative values. Balanced anaesthesia with pethidine and fentanyl seem to have minor influence on gastroduodenal motility and gastric emptying rate.

Antroduodenal motility and gastric emptying. Gastroduodenal motility and pH following ingestion of paracetamol.

The influence of paracetamol on antroduodenal motility and gastric pH was studied in 11 healthy subjects and the relationship between gastroduodenal motility and gastric emptying rate time, tmax, to peak concentration of serum paracetamol, Cmax, was evaluated. The incidence of antral phase III activity and the duration of phase III was diminished with paracetamol (P less than 0.05). The other motility parameters assessed were unchanged. Three patterns of motility and absorption were observed. One group (n = 5) were fast absorbers with a tmax of 1 h and a motility pattern characterized by antral activity, a high motility index and a short duration of phase II (33-60 min); the phase IIIs were complete except in one case. The second group (n = 4) had tmax at 1.5 h and their phase II motility was characterized by a longer duration (80-133 min) (P less than 0.05), by antral activity, and by a high motility index; their phase IIIs were all incomplete. The last group (n = 2) were slow absorbers: Cmax was not reached in the investigation period, no antral contractions were seen, and the motility index was low. The area under the serum-concentration curve of paracetamol differed between the groups at 90 and 180 min (P less than 0.01).

Effects of general anaesthesia with halothane on antroduodenal motility, pH and gastric emptying rate in man.

Antroduodenal motility, pH and gastric emptying rate were measured in 11 patients undergoing orthopaedic or plastic surgery with general anaesthesia. Motility was measured by manometry and gastric emptying rate by the rate of paracetamol absorption. During anaesthesia, gastric emptying was delayed in eight patients. General anaesthesia with halothane reduced the duration of the interdigestive motility complex (P less than 0.01), mainly by a shortening of phase II (P less than 0.01) which correlated with the inhaled concentrations of halothane (P less than 0.01). Anaesthesia impeded the occurrence of antral contractions during phase II (P less than 0.01); the frequency of contractions was unchanged during anaesthesia, but decreased during the recovery period (P less than 0.01). The amplitudes of antral contractions diminished with anaesthesia (P less than 0.01), but increased after operation. The frequency of contractions in the duodenum was unchanged during phase II and reduced during phase III (P less than 0.01). Gastric pH increased during and after operation (P less than 0.01). General anaesthesia with halothane affects gastroduodenal motility especially during phase II, increases gastric pH and delays gastric emptying rate.

Ossification of the cricothyroid membrane following minitracheotomy.

We describe a case in which a repeat minitracheotomy (MT) could not be performed 2 months after the first. The cricothyroid membrane seemed calcified and histological examination showed scar formation with dystrophic calcification and heterotopic bone formation. Scar formation following MT may have caused these alterations making repeat access to the airway through the membrane impossible.

Gastrointestinal motility and gastric pH and emptying following ingestion of diazepam.

The effects of diazepam on antroduodenal motility, gastric pH and gastric emptying rate were investigated in 10 volunteers. Gastric emptying was assessed using paracetamol absorption and antroduodenal motility and pH by means of a perfused multilumen tube. On the first study day, the volunteers received paracetamol in phase I after the occurrence of one complete interdigestive motility complex (IDMC). Diazepam was given on the second study day at the beginning of the first phase I and paracetamol was given one IDMC later. The rate of absorption correlated with motility (P less than 0.03). Some volunteers were fast absorbers on the first study day and slow on the second, indicating that absorption rate is not constant, but dependent on gastroduodenal motility. Diazepam tended to increase the gastric emptying rate and enhanced the amplitude of contractions and the motility index during phase II (P less than 0.02). Gastric pH increased after ingestion of diazepam (P less than 0.05).

A model for acute haemodynamic studies in the ascending aorta in pigs.

Since data on velocity fields in the ascending aorta downstream of normal aortic valves in pigs have not yet been obtained velocity profiles were visualised using a hot film anemometer needle probe before and after total cardiopulmonary bypass and cold cardioplegic arrest. Furthermore, measurements were made during increased heart rate and cardiac output. A dynamic three dimensional visualisation of velocity fields showed a skewed clockwise rotating velocity profile, developing from peak systole and continuing throughout the systolic deceleration phase. This pattern was consistent regardless of the haemodynamic state. Heart rate was increased to 180 beats.min-1 and cardiac output by a maximum of 91%. It is concluded that the pig model is valuable for haemodynamic studies in the ascending aorta before and after cold cardioplegic arrest and that the velocity profiles found in this study are important basic data for velocity field studies downstream of artificial heart valves implanted in the aortic position.

Velocity fields and turbulent stresses downstream of biological and mechanical aortic valve prostheses implanted in pigs.

Since detailed knowledge about velocity fields downstream of heart valve prostheses obtained from in vitro studies has not been followed up by similar detailed studies in vivo a pig model for acute velocity field studies downstream of aortic valve prostheses was established. Two mechanical and two bioprosthetic valves were studied and a dynamic three dimensional visualisation of velocity fields one diameter downstream performed under different haemodynamic conditions in a total of 22 pigs. The Ionescu-Shiley pericardial valve had velocity fields very similar to the normal native porcine aortic valve. The Edwards-Carpentier porcine valve caused a jet type flow, and the valve design of the St Jude Medical and Björk-Shiley Monostrut valves was reflected in the velocity profile. Normalised (mean(SEM] systolic Reynolds normal stresses in the total cross sectional area were: native porcine 15(1.5) Nm-2; St Jude Medical 24(3.4) Nm-2; Björk-Shiley Monostrut 25(1.6) Nm-2; Edwards-Carpentier Supra-annular 51(6.6) Nm-2; Ionescu-Shiley Pericardial 19(2.0) Nm-2. Reynolds normal stresses were higher in areas of rapidly changing or constantly high velocity gradients.

Minitracheotomy in the treatment of postoperative sputum retention and atelectasis.

Minitracheotomy (MT) is a new method for the treatment of sputum retention and atelectasis. Through a 1-cm incision in the cricothyroid membrane (coniotomy), a specially designed tube is placed in the trachea, allowing suction to be performed. Fifteen patients, aged 37-78 years (median 62 years), with postoperative sputum retention, atelectasis and imminent respiratory failure, were treated with suction by MT. Thirteen of the patients recovered from their respiratory problems, while two patients had to be treated with intermittent positive pressure ventilation (IPPV). During insertion, one case of external bleeding and one case of subcutaneous and mediastinal emphysema were seen, while no complications were seen during cannulation. The duration of cannulation was 4-38 days (median 10 days). Following decannulation the incisions were airtight within 1 day and healed within 3 days. Ten patients left hospital in good health and five died because of surgical complications and/or cardiovascular failure. MT seems to be effective in the treatment of sputum retention and atelectasis. Advantages over other invasive methods make it a method of first choice. The method involves few complications and is often so effective that avoidance of intubation and IPPV is possible.

Insulin treatment of the insulin-dependent diabetic patient undergoing minor surgery. Continuous intravenous infusion compared with subcutaneous administration.

In a prospective randomised study in 20 insulin-dependent diabetics who had minor surgery under general anaesthesia we compared the metabolic responses to intravenous glucose-insulin-potassium infusion with those who had conventional subcutaneous insulin administration. The former treatment resulted in lower blood glucose levels both during the infusion period (p less than 0.05) as well as the entire observation period (operative, first and second postoperative days; p less than 0.01). More blood glucose values were within the intended range of 5 to 10 mmol/litre in the glucose-insulin-potassium as compared to the conventional group (48% versus 24%; p less than 0.01). The levels of lactate, 3-hydroxybutyrate, glycerol, alanine, glucagon, insulin and growth hormone did not differ between the two groups. The infusion regimen resulted in better glycaemic control both peri-and postoperatively than the conventional subcutaneous insulin regimen in insulin-dependent diabetic patients who have minor surgery.