Facial trauma.

Facial trauma. Patients with facial trauma must be assessed in a systematic way so as to avoid missing any injury. Severe and disfiguring facial injuries can be distracting. However, clinicians must first focus on the basics of trauma care, following the Advanced Trauma Life Support (ATLS) system of care. Maxillofacial trauma occurs in a significant number of severely injured patients. Life- and sight-threatening injuries must be excluded during the primary and secondary surveys. Special attention must be paid to sight-threatening injuries in stabilized patients through early referral to an appropriate specialist or the early initiation of emergency care treatment. The gold standard for the radiographic evaluation of facial injuries is computed tomography (CT) imaging. Nasal fractures are the most frequent isolated facial fractures. Isolated nasal fractures are principally diagnosed through history and clinical examination. Closed reduction is the most frequently performed treatment for isolated nasal fractures, with a fractured nasal septum as a predictor of failure. Ear, nose and throat surgeons, maxillofacial surgeons and ophthalmologists must all develop an adequate treatment plan for patients with complex maxillofacial trauma.

Epidemiology of ENT emergencies.

OBJECTIVE: To give an overview of ear, nose, and throat (ENT) pathologies encountered in the emergency room (ER). METHODS: Retrospective analysis of 1296 files of patients visiting the ER between January 2008 and December 2012. Diagnosis, treatment, hospitalisation, referral, and demographic parameters were evaluated. RESULTS: Epistaxis is the most frequent ENT condition seen in the ER. One third of epistaxis patients are on anticoagulant therapy. The second most frequent conditions observed were infections of the pharynx and tonsils. Nasal fractures and vertigo were also frequently observed. CONCLUSION: Epistaxis and its treatment were the most frequent ENT diagnosis and therapy seen in the ER. Infections are the main cause of hospitalisation. Referral to other disciplines and revisits seldom occurred.

Outcome and quality of screening in a nationwide survey on retinopathy of prematurity in The Netherlands.

PURPOSE: Provide insight in natural history, screening and treatment policy of retinopathy of prematurity (ROP) in The Netherlands. METHODS: A multicentre, prospective, population-based study (NEDROP) included all preterm infants born in 2009 in The Netherlands fulfilling the inclusion criteria for ROP screening. Anonymised data from ophthalmologists, neonatologists and paediatricians were merged on identification number. RESULTS: Of 2033 reported infants, 1688 (83%) were screened for ROP. ROP stage was reported in 100%, zone in 94.4% and plus disease in 83%. ROP developed in 324 (19.2%), mild ROP (stage 1-2) in 294 (17.4%), severe ROP (stage 3 or more) in 30 (1.8%) and 17 (1%) were treated. The initial screening examination was not performed within the required 42 days in 641 (38%). Date for follow-up was recorded 1973 times and accomplished within 3 days from the planned date in 1957 (99.2%). The chance of not being screened increased from 12.9% without transfer to another hospital to 23.5, 18.5 and 25% after 1, 2, or 3 transfers, respectively. CONCLUSIONS: The incidence of severe ROP and infants treated was low. NEDROP emphasises that timing of initial examination and transfer to another hospital are issues of concern within the screening process.

Comparing the microdebrider and standard instruments in endoscopic sinus surgery: a double-blind randomised study.

UNLABELLED: Comparing the microdebrider and standard instruments in endoscopic sinus surgery: a double-blind randomised study. OBJECTIVE: It is frequently stated that microdebriders provide better mucosal preservation in endoscopic sinus surgery (ESS), and therefore better and faster healing, when compared to the standard Blakesley instruments. However, evidence from comparative prospective studies is lacking. In this study, we compared the results of microdebriders with traditional surgical instruments for ESS. METHODS: A prospective, randomised, comparative, double-blind study in 50 patients undergoing bilateral ESS. Each patient was operated on with both instruments: one side of the nose with the microdebrider only, and the other side with standard instruments. The outcome of surgery was measured by using a symptom score and an endoscopic score at five time points during the first six postoperative months. RESULTS: Both instruments resulted in symptom improvement and in endoscopically visible healing over time, but no significant difference was found between the two techniques. In endoscopic evaluation, only the total score at 3 weeks after surgery was significantly better in the microdebrider group. No significant difference was found at any other time point. Synechia formation, patency of middle meatal antrostomy, and open access to the ethmoid were the same in both groups. CONCLUSION: In this study of endoscopic sinus surgery the use of the microdebrider does not offer major advantages compared to the standard instruments.

Peri-operative levels of s-100 protein in serum: marker for surgical manipulation and postoperative complications.

Although minimally invasive neurosurgical techniques are highly sophisticated nowadays, almost any operative procedure causes an inevitable surgical trauma to the brain. As a consequence unfavorable functional outcomes are not rare. Intraoperative biochemical monitoring can be helpful first to detect but also to prevent brain damage. We investigated if serum S-100 protein (S-100) levels are a reliable marker for the extent of acute cerebral damage caused by surgical trauma or postoperative complication. S-100 is present in the cytosol of glial cells. This protein leaks into the extracellular space after cell damage and can be detected both in the cerebrospinal fluid (CSF) and serum. To determine S-100 protein levels, serum samples from 20 patients with various intracranial tumors were collected before surgery, and at one day, as well as at seven days after surgery. It was hypothesised that the size of the tumor-brain contact surface (TBCS) was closely related to the dimension of the surgical trauma. TBCS was measured from radiological imaging. The pre- and postoperative (day 1 and day 7) clinical condition of each patient was assessed. The S-100 levels were correlated with the TBCS and the clinical condition. Levels of S-100 on day 1 and day 7 were significantly higher as compared with levels on day 0 ( p = 0.02, respectively p = 0.01). There was a significant relationship between rise of S-100 level and worsening of clinical condition between day 0 and day 1 ( p = 0.001). Also a significant positive relationship between TBCS and the level of S-100 could be found on day 1 and on day 7 ( R = 0.71, p = 0.0009, respectively R = 0.73, p = 0.004). Furthermore, a significant relationship between the rise of S-100 level between day 0 and day 1, as well as between day 0 and day 7, and TBCS could be documented ( R = 0.61, p = 0.01, respectively R = 0.64, p = 0.005). In conclusion, serum S-100 levels are a reliable marker for acute or recent CNS damage caused by neurosurgical manipulation or as a result of secondary postoperative complications. Therefore, intraoperative monitoring of serum S-100 levels seems very promising. In such a setting the negative effects of surgical manipulation can be measured instantaneously, which should bring the neurosurgeon to change his strategy. As a consequence the surgical trauma can be minimized and functional outcome can be optimized.

Prognostic factors for the vascular components of erectile dysfunction in patients on renal replacement therapy.

A total of 76 male patients on renal replacement therapy (RRT) were investigated. Erectile dysfunction (ED) was defined as insufficient erection during visual erotic stimulation (VES) or during sleep as measured with Rigiscan and Erectiometer. Data on medical history, physical examination, and laboratory variables were collected. Furthermore, penile pharmacological duplex ultrasonography (PPDU) was performed. Univariate and multivariate logistic regressions were used to determine prognostic values and to develop prognostic models. Independent prognostic factors for ED were the number of cardiovascular events, waist-hip ratio, body mass index, and acceleration time (AT) as measured with PPDU. Independent prognostic factors for an abnormal AT (>100 ms) were number of cardiovascular events, age category, and the presence of carotid bruits. Independent prognostic factors for insufficient veno-occlusion during PPDU were number of cardiovascular events and supine diastolic blood pressure. The vascular contribution to ED in patients on RRT is substantial. Data from medical history, limited physical examination, and PPDU contribute to the prediction of the vascular contribution to ED.

Septal suturing following nasal septoplasty, a valid alternative for nasal packing?

Septal suturing following nasal septoplasty, a valid alternative for nasal packing? After septal surgery most surgeons still routinely perform nasal packing since this is generally recommended. The aims of packing are numerous: haemostasis, prevention of haematoma, increase septal flap apposition, closure of dead space and prevention of displacement of the replaced cartilage. However, nasal packing is not an innocuous procedure and may lead to cardiovascular changes, continued bleeding, nasal injury, hypoxia, foreign body reaction or infection. The major disadvantage of nasal packing is patient discomfort--usually necessitating hospital stay--and the need to administer antibiotics. Therefore alternatives were sought. Sessions, Lee and Vukovic conceived and reported in the eighties forms of continuous septal suturing, but are not widely used. A similar technique of septal suturing after nasal septoplasty without nasal packing was used in 226 consecutive surgical procedures and reviewed retrospectively. Complications like postoperative episodes of bleeding, infections, septal haematomas, septal perforations or synechia were not noted. On one patient a recurrence of the septal deviation occurred. Patients reported almost no discomfort. Moreover, the septal surgery procedure could be carried out on a day-surgery basis. Readmission of a patient was never necessary. Based on these observations the septal suturing technique is a valid alternative to intranasal packing following septal surgery.

S100B protein, glia and Gilles de la Tourette syndrome.

Activated glial cells play an important role in a variety of neurological disorders. This study examines S100B protein levels in the serum of patients with Gilles de la Tourette syndrome, as potential marker for glial cell function. Two groups of children were examined: 61 reference patients and 33 patients with Gilles de la Tourette syndrome. It was found that S100B serum concentrations in the reference group decrease with increasing age. Furthermore it was found that the mean S100B concentration in serum of children with Gilles de la Tourette syndrome is significantly higher than in the reference group. These preliminary results suggest that glial tissue might be involved in the pathophysiology of the syndrome.

Sexual dysfunction after renal replacement therapy.

The existence of a sexual problem as the subjective evaluation of sexual function was assessed with a simple questionnaire. Those questioned were patients undergoing dialysis treatment (n = 400) or with a functioning renal transplant (RTx; n = 300) and both men and women in the general Dutch population (n = 591). In the Dutch control population, 8.7% of the men and 14.9% of the women reported a sexual problem, showing a significant gender difference but unrelated to age. In patients, the prevalence of a sexual problem was significantly greater (hemodialysis, men, 62.9%; women, 75.0%; peritoneal dialysis, men, 69.8%; women, 66.7%; renal transplantation, men, 48.3%; women, 44.4%). In RTx recipients, sexual problems were significantly less prevalent than in patients undergoing dialysis (P < 0.001). Only in male patients was an association between prevalence of a sexual problem and age found. The results of the simple questionnaire were sufficiently validated when 102 of 104 patients confirmed their responses in a subsequent structured interview. This study shows that the prevalence of sexual problems in patients undergoing renal replacement therapy is high and clinically relevant.

Cerebrospinal fluid C3 and C4 indexes in immunological disorders of the central nervous system.

OBJECTIVES: Validation of cerebrospinal fluid (CSF) indexes as a measure for intrathecal C3 and C4 production. Examination of their role in differential diagnosis of immunological disorders of the central nervous system (CNS). MATERIAL AND METHODS: Correlative study in controls (low back pain without disk herniation) between the CSF/serum ratio (Q) for albumin, and Q C3 and Q C4. Comparative study of C3 and C4 indexes in patients with CNS dysfunction due to relapsing-remitting (RR) multiple sclerosis (MS), secondary progressive (SP) MS, systemic lupus erythematosus (SLE), and human immunodeficiency virus (HIV) infection. RESULTS: Strong and statistically highly significant correlations between Q albumin and Q C3 (r=0.89, P=0.0001), and Q C4 (r=0.68, P= 0.0001). In MS patients decreased mean values for serum (RR, SP) and CSF (RR) C3, and increased C3 index mean value (RR, SP). In CNS SLE increase of mean C3 and C4 index values. In CNS HIV increase of mean C3 and C4 index values, and CSF C3 and C4 concentrations. Most individual index values were within the reference range. CONCLUSION: CSF index is a valid tool to detect intrathecal C3 or C4 production. C3 or C4 index contributes little to the differential diagnosis of immunological CNS disorders. C3 might play a pathogenic role in various immunological CNS disorders.

Photorefractive keratectomy with an ablatable mask for myopic astigmatism.

PURPOSE: To evaluate efficacy, safety, and stability of photoastigmatic keratectomy (PARK) carried out with a Summit Apex Plus laser using an ablatable mask. METHODS: Forty-one eyes of 41 patients with myopic astigmatism with follow-up of 12 months were evaluated. Treatment efficacy was compared in groups with high (>6.00 D) versus low (< or =6.00 D) preoperative spherical equivalent subjective manifest refraction, in groups with high (>2.00 D) versus low (< or =2.00 D) preoperative cylindrical component and in groups divided according to preoperative axis of cylinder. RESULTS: At 12 months after surgery, mean spherical equivalent manifest refraction in all 41 eyes was -0.30 +/- 0.90 D. Mean cylinder component was 0.60 +/- 0.70 D. Mean reduction in astigmatic component was 67 +/- 47%. Uncorrected visual acuity of 0.5 or more was achieved in 79% of eyes; 71% of eyes achieved 0.8 or more. At 1 month after surgery, 49% of eyes had a loss of 2 or more lines of spectacle-corrected visual acuity. This loss was restored at 12 months. No statistically significant differences were found between the different subgroups. CONCLUSION: Photoastigmatic keratectomy with ablatable mask gives satisfactory results. No relation in efficacy was found when taking into account the amount of preoperative spherical component, the cylindrical component, or the cylinder axis direction.

Hypermobility and peripartum pelvic pain syndrome in pregnant South African women.

OBJECTIVE: To determine the incidence and correlation of joint hypermobility (HM) and peripartum pelvic pain (PPPP) in an homogeneous pregnant South African population. STUDY DESIGN: A cross-sectional study among Cape Coloured pregnant women. Joint mobility was measured by Beighton score; PPPP with a specially developed PPPP score. RESULTS: Using the Beighton scores with a cut-off point of HM > or = 5/9, only 4.9% of the 509 pregnant women were hypermobile. Hyperextension of the elbow was the largest contributor to HM (35.4%). No correlation of HM with the incidence of PPPP was established. Only 20 very mild cases of PPPP were recorded. Back pain increased significantly during pregnancy to a mean of 38%. Right handedness occurred in 95.9%. No significant relation was found between HM and the non-dominant side. CONCLUSION: Hypermobility in pregnant Cape Coloured women was surprisingly low (4.9%) with a decrease with age, but no increase during pregnancy. Peripartum pelvic pain is virtually absent and has no correlation with joint laxity. Back pain increased during pregnancy to a mean of 38%. Right handedness was high (96%) in comparison with the world-wide figure of 85%. No correlation was found between the dominant body side and hypermobility.

Treatment for extended-mid and distal ureteral stones: SWL or ureteroscopy? Results of a multicenter study.

PURPOSE: In a randomized study, we analyzed the treatment results of ureterorenoscopy (URS) and shockwave lithotripsy (SWL) for extended-mid and distal ureteral stones. We investigated also, for reasons of cost effectiveness, the factors influencing the outcome, the complications, and the need for auxiliary procedures. PATIENTS AND METHODS: In three regional hospitals, we selected 156 patients with extended-mid and distal ureteral stones. After randomization, 87 were treated with URS, and 69 with SWL. The treatment results were studied in relation to complications, the need for auxiliary procedures and stone factors, urinary tract infection (UTI), dilatation, and kidney function. RESULTS: After retreatment of 45% of the patients, the stone-free rate after 12 weeks in the SWL group was 51%. After a retreatment rate of 9% of the patients in the URS group, the stone-free rate was 91%. Including the number of auxiliary procedures, we calculated the Efficiency Quotient (EQ) as 0.50 for SWL and 0.38 for URS. After correction and redefinition of auxiliary procedures, the EQ was 0.66. The mean treatment time for SWL was 52 minutes and for URS 39 minutes. General anesthesia was more frequently needed in URS patients. Complications occurred more often in the URS group (22 v 3 and 24 v 13, respectively). These were mostly mild, and all could be treated with a double-J stent, antibiotics, or analgetics. A lower stone-free rate was achieved in patients with larger (> or =11 mm) stones (75% v 85% for smaller stones in the URS group and 17% v 73% in the SWL group. In the URS group, the stone-free rate of patients with extended-mid ureteral stones was lower than that of patients with distal ureteral stones. Calculating the costs for URS and SWL appeared impossible because of the differences in available equipment. CONCLUSION: The stone-free rate after URS is much higher than after SWL, and the EQ in our series was strongly dependent on definitions. The decision about how to treat a patient with an extended-mid or distal ureteral stone therefore should not be made primarily on the basis of cost effectiveness but rather on the basis of the availability of proper equipment, the experience of the urologist, and the preference of the patient.

Composite cerebrospinal fluid score in relapsing-remitting and secondary progressive multiple sclerosis.

We investigated whether cerebrospinal fluid (CSF) analysis may differentiate between relapsing-remitting (RR) and secondary progressive (SP) multiple sclerosis (MS). In 17 RR and 16 SP patients we determined: albumine CSF/PB ratio; mononuclear cell (MNC) number, CD4+, CD8+, and B1+ subsets, CD4+/CD8+ ratio; IgG, IgG index, IgM, IgM index, complement components C3 and C4, and C3 and C4 indexes; myelin basic protein; neuron-specific enolase (NSE); S100; and lactate. For each parameter the statistical distance was calculated. Then, using linear discriminant analysis, we computed a discriminant score, including only variables with a P value less than or equal to 0.15: albumin CSF/PB ratio, MNC number, IgM, IgM index, C3, C4, NSE, S100, and lactate. The discriminant score allocated all 17 RR patients to the RR group and 15 of 16 SP patients to the SP group. We conclude that RR and SP MS patients differ with respect to CSF profile and that in individual patients a composite CSF score may differentiate between RR and SP MS.

Cerebrospinal fluid analysis differentiates between relapsing-remitting and secondary progressive multiple sclerosis.

OBJECTIVES: To find whether CSF analysis may differentiate between relapsing-remitting and secondary progressive multiple sclerosis. METHODS: In 17 patients with relapsing-remitting and 16 patients with secondary progressive multiple sclerosis, all without current or recent relapses, albumin CSF: peripheral blood ratio, mononuclear cell number, CD4+, CD8+, and B1+ subsets, CD4+:CD8+ ratio, IgG, IgG index, IgM, IgM index, complement components C3 and C4, and C3 and C4 indices, myelin basic protein, neuron specific enolase, S100, and lactate were determined. For each measure the statistical distance measure D2 was calculated. For computation of a discriminant score variables with a P value< or =0.15 were included (two sided univariate t test). These were albumin CSF: peripheral blood ratio, mononuclear cell number, IgM, IgM index, C3, C4, neuron specific enolase, S100, and lactate. Simultaneous distributions of the variables were compared between both groups (multivariate t test) and a discriminant score was computed (linear discriminant analysis). RESULTS: The discriminant score allocated all 14 relapsing-remitting patients to the relapsing-remitting group (positive score) and 12 of 13 secondary progressive patients to the secondary progressive group (negative score). One secondary progressive patient was allocated to the relapsing-remitting group. CONCLUSIONS: Patients with relapsing-remitting or secondary progressive multiple sclerosis differ in CSF profile and CSF analysis may help to differentiate between relapsing-remitting and secondary progressive multiple sclerosis.

[Results of photorefractive keratectomy using the excimer laser in the treatment of myopia; 1-year follow-up]. / Resultaten van fotorefractieve keratectomie met de excimer-laser ter behandeling van myopie; 1 jaar follow-up.

OBJECTIVE: Evaluation of the first excimer laser treatments of myopia. DESIGN: Descriptive. SETTING: Excimer Laser Centrum, Department of Ophthalmology, University of Nijmegen, Nijmegen, the Netherlands. METHOD: 312 patients underwent spherical excimer laser treatment to correct myopia of 1.2 up to 10 diopters between February 1992 and October 1993. 245 patients completed a follow-up of one year or more; 36 retreatments were carried out. Group I (treatment 1.2 to 6 D) numbered 174 patients, group II (6.1-10 D) 71 patients. RESULTS: After a follow-up period of one year or just before retreatment 79% of group I and 48% of group II achieved a refractive correction within 1 D of the attempted correction. Visual acuity without correction was 0.5 or more in 94% of group I and in 76% of group II. Less than one percent (n = 1) of group I and 6% (n = 4) of group II lost more than one line of best corrected visual acuity. Retreatment could correct 50% of those eyes that did not achieve a refraction within 1 D of attempted correction. Loss of visual acuity was corrected by retreatment in 5 of 6 cases of group I and in 7 of 11 cases of group II. CONCLUSION: Based on a one-year follow-up, refractive surgery with the excimer laser appears to correct myopia between 1 and 10 D effectively. Predictability is diminishing on correcting higher amounts of refractive error. Thorough information of the patients regarding the results to be expected will prevent disappointment.

Relationship between lower urinary tract abnormalities and disease-related parameters in multiple sclerosis.

Multiple sclerosis affects the lower urinary tract in many patients. The relationship between lower urinary tract abnormalities and disease-related parameters of multiple sclerosis is not well described. We screened urologically and neurologically 212 patients according to a standard protocol. Micturition complaints were noted in 52% of the patients and urodynamic abnormalities were found in 64%. A statistical correlation was found between detrusor hyperactivity and detrusor hypoactivity with disease-related parameters, that is disease duration, disability status, myelin basic protein concentration in the cerebrospinal fluid and neurophysiological investigations. No relationship was found between detrusor hypersensibility or detrusor hyposensibility and the aforementioned disease-related parameters. In 1 patient upper urinary tract abnormalities were noted in combination with urodynamic abnormalities. We conclude that lower urinary tract abnormalities can be found in every patient with multiple sclerosis unrelated to the state of the disease. Severe upper urinary tract abnormalities are rare.

Comparison of biothesiometry and neuro-urophysiological investigations for the clinical evaluation of patients with erectile dysfunction.

In the literature the determination of the vibration sensitivity threshold of the penile glans by means of biothesiometry has been introduced as a cost-effective office test for the evaluation of penile neuropathy in impotent men. At our facility we have gained extensive experience with neuro-urophysiological tests for the evaluation of penile innervation. These neuro-urophysiological tests have the disadvantage of complexity, invasiveness and time consumption. In our study both methods were compared in 31 impotent patients. The results showed that penile glans biothesiometry yields consistent results when measurements are repeated during 1 session. However, no relationship was found between the outcome of penile glans biothesiometry and neuro-urophysiological tests of the dorsal penile nerve, which is probably due to the fact that vibration is not an adequate stimulus to the skin of the penile glans that contains free nerve endings (that is pain receptors) only, and hardly any vibration receptors. We conclude that biothesiometric investigation of penile glans innervation is unsuited for the evaluation of penile innervation and cannot replace neuro-urophysiological tests.

Use of sacral reflex latency measurements in the evaluation of neural function of spinal cord injury patients: a comparison of neuro-urophysiological testing and urodynamic investigations.

Complete suprasacral spinal cord injury is followed by great changes in the neural control and function of the lower urinary tract. In the literature there is some controversy about the relationship between detrusor function and results of neurophysiological tests of sacral root conduction after the spinal shock phase. Therefore, we studied this relationship in a group of 73 patients with clinical as well as neurophysiological documented complete suprasacral spinal cord injury, and compared sacral reflex latency measurements (bulbocavernosus and urethro-anal reflexes) with detrusor function, documented by urodynamic investigation. A high incidence of sacral reflex latency abnormalities was found. Comparison of sacral reflex latencies with detrusor reflex activity showed a statistical significant correlation. No such relationship could be found between urodynamic characteristics of the detrusor in patients with detrusor hyperreflexia and sacral reflex latency measurements. We conclude that sacral reflex latency measurements can give an indication about the existence of reflex detrusor activity. On the other hand, these neurophysiological measurements do not provide a reliable indication of the detrusor function after complete spinal cord injury.

Effects of chlormadinone acetate, acetazolamide and oxygen on awake and asleep gas exchange in patients with chronic obstructive pulmonary disease (COPD).

The purpose of this study was to assess the short-term effects of chlormadinone acetate (CMA), a synthetic progestogen, acetazolamide (ACET) and oxygen on awake and asleep blood gas values. The study was conducted according to a randomized, double-blind and placebo-controlled design in 53 hypoxaemic patients with chronic obstructive pulmonary disease. On the first two consecutive nights, all patients received either room air or oxygen, via a nasal cannula, in random order. They then received either CMA (25 mg), ACET (250 mg) or placebo twice a day, all in identical capsules. On the third study night, after one week of drug treatment, the patients were tested breathing room air. CMA and ACET therapy decreased mean daytime arterial carbon dioxide tension (PaCO2) by 0.7 and 0.5 kPa, respectively, and night-time end-tidal carbon dioxide tension (PETCO2) by 0.5 and 0.3 kPa, respectively. Supplemental oxygen caused increased CO2 retention during the day and night (0.6 and 0.3 kPa, respectively. Daytime arterial oxygen tension (PaO2) increased to the same extent during ACET (1.9 kPa) and oxygen (2.5 kPa). Asleep oxygen saturation improved most with oxygen supplementation (7%), although ACET also caused significant improvement (4%). CMA administration had virtually no effect on mean awake and asleep hypoxaemia. ACET therapy significantly improved subjective sleep quality. On CMA, minute ventilation increased in association with an augmentation of the hypercapnic ventilatory response. ACET treatment increased both hypercapnic and hypoxic ventilatory responses. We conclude from the group of patients with COPD studied, that the short-term effects of ACET treatment on gas exchange compare favourably with those of CMA. Oxygen therapy improves oxygenation slightly more than ACET, but aggravates CO2 retention.