Ventilatory Distress Research Articles

Determining the effects of elevated partial pressure of oxygen on hypercapnia-induced cerebrovascular reactivity

Evaluation of cerebrovascular reactivity (CVR) to hypo- and hypercapnia is a valuable test for the assessment of vasodilatory reserve. While hypercapnia-induced CVR testing is usually performed at normoxia, mild hyperoxia may increase tolerability of hypercapnia by reducing the ventilatory distress. However, the effects of mild hyperoxia on CVR was unknown. We therefore recruited 21 patients with a range of steno-occlusive diseases and 12 healthy participants who underwent a standardized 13-minute step plus ramp CVR test with a carbon dioxide gas challenge at the subject’s resting end-tidal partial pressure of oxygen or at mild hyperoxia (PetO2 = 150 mmHg) depending on to which group they were assigned. In 11 patients, the second CVR test was at normoxia to examine test-retest differences. CVR was defined as % Δ Signal/ΔPetCO2. We found that there was no significant difference between CVR test results conducted at normoxia and at mild hyperoxia for participants in Groups 1 and 2 for the step and ramp portion. We also found no difference between test and retest CVR at normoxia for patients with cerebrovascular pathology (Group 3) for step and ramp portion. We concluded normoxic CVR is repeatable, and that mild hyperoxia does not affect CVR.

A pragmatic approach and treatment of coronavirus disease 2019 (COVID-19) in intensive care unit.

There is a new global pandemic that emerged in China in 2019 that is threatening different populations with severe acute respiratory failure. The disease has enormous potential for transmissibility and requires drastic governmental measures, guided by social distancing and the use of protective devices (gloves, masks, and facial shields). Once the need for admission to the ICU is characterized, a set of essentially supportive therapies are adopted in order to offer multi-organic support and allow time for healing. Typically, patients who require ventilatory support have bilateral infiltrates in the chest X-ray and chest computed tomography showing ground-glass pulmonary opacities and subsegmental consolidations. Invasive ventilatory support should not be postponed in a scenario of intense ventilatory distress. The treatment is, in essence, supportive.

Severe pain-related adverse events of percutaneous dilatational tracheostomy performed by a neurointensivist compared with conventional surgical tracheostomy in neurocritically ill patients

BackgroundWe evaluated severe pain-related adverse events (SAE) during the percutaneous dilatational tracheostomy (PDT) procedure performed by a neurointensivist and compared the outcomes with that of conventional surgical tracheostomy in neurocritically ill patients.MethodsThis was a retrospective and observational study of adult patients who were admitted to the neurosurgical intensive care unit between January 2014 and March 2018 and underwent tracheostomy. In this study, primary endpoints were incidence of SAE: cardiac arrest, arrhythmias, hypertension, hypotension, desaturation, bradypnea, or ventilatory distress. The secondary endpoint was procedure-induced complications.ResultsA total of 156 patients underwent tracheostomy during the study. Elective surgery of brain tumors (34.0%) and intracranial hemorrhage (20.5%) were the most common reasons for admission. The most common reasons for tracheostomy were difficult ventilator weaning or prolonged intubation (42.9%) and sedative reduction (23.7%). Tachycardia (30.1%) and hypertension (30.1%) were the most common SAE. Incidence of SAE was more common in conventional tracheostomy compared to PDT (67.1% vs. 42.3%, P = 0.002). The total duration of SAE (19.8 ± 23.0 min vs. 3.4 ± 5.3 min, P < 0.001) and procedural time (42.2 ± 21.8 min vs. 17.7 ± 9.2 min, P < 0.001) were longer in conventional tracheostomy compared to PDT. Multivariable adjustment revealed that only PDT by a neurointensivist significantly reduced the incidence of SAE by one third (adjusted odds ratio [OR]: 0.36, 95% confidence interval [CI]: 0.187–0.691). In addition, PDT by a neurointensivist deceased the duration of SAE by 8.64 min (β: -8.64, 95% CI: − 15.070 – -2.205, P = 0.009) and prolonging the procedure time by every one minute significantly increased the duration of SAE by 6.38 min (β: 6.38, 95% CI: 0.166–0.470, P < 0.001). Procedure-induced complications were more common in conventional tracheostomy compared to PDT (23.5% vs. 11.3%, P = 0.047).ConclusionsThis retrospective and exploratory study of our single-center limited cohort of tracheostomy patients revealed that decreased SAE may be associated with short procedural time during the PDT procedure performed by a neurointensivist. It is proposed that PDT by a neurointensivist may be safe and feasible in neurocritically ill patients.

Physiological changes associated with routine nursing procedures in critically ill are common: an observational pilot study

Nursing procedures that are routinely performed in the intensive care unit (ICU) are assumed to have minimal side effects. However, these procedures may sometimes cause physiological changes that negatively affect the patient. We hypothesized that physiological changes associated with routine nursing procedures in the ICU are common. A clinical observational study of 16 critically ill patients in a nine-bed mixed university hospital ICU. All nursing procedures were observed, and physiological data were collected and subsequently analyzed. Minor physiological changes were defined as minimal changes in respiratory or circulatory variables, and major physiological changes were marked as hyper/hypotension, bradycardia/tachycardia, bradypnea/tachypnea, ventilatory distress, and peripheral blood oxygen desaturation. In the 16 patients, 668 procedures generated 158 major and 692 minor physiological changes during 187 observational hours. The most common procedure was patient position change, which also generated the majority of the physiological changes. The most common major physiological changes were blood oxygen desaturation, ventilatory distress, and hypotension, and the most common minor changes were arterial pressure alteration, coughing, and increase in respiratory rate. In this pilot study, we examined physiological changes in connection with all regular routine nursing procedures in the ICU. We found that physiological changes were common and sometimes severe.

Effect of implementing structured communication messages on the clinical outcomes of unconscious patients

Background: Patient communication is one of the most important factors associated with quality of care and patient safety, especially in Intensive Care Units (ICUs). However, relatively little is known about the different aspects of communication with unconscious patients, and the effect of communication and outcome measures. Aim: This study aimed to examine effects of implementing structured communication messages (SCMs) on the clinical outcomes of unconscious patients. Methods: A quasi-experimental design was utilized. Sixty unconscious patients were selected from three ICUs of Emergency Hospital of Mansoura University and two ICUs at Main Hospital of Mansoura University. Patients were randomly allocated into two groups (intervention and control group) 30 patients in each. Four tools were used for data collection: physiological adverse events (PAE) assessment tool including (hyperthermia, hypothermia, tachycardia, bradycardia, hypertension, hypotension, hypovolemia, hypervolemia, desaturation, bradypnea, ventilatory distress, hyperglycemia or hypoglycemia), Full Outline of Un-Responsiveness (FOUR) scale, Behavioural Pain Scale (BPS), and Motor Activity Assessment Scale (MAAS). Results: The implementation of SCMs was associated with a decreased incidence of PAE and a statistically significant positive effect on level of consciousness revealed by FOUR scale. Patients in the intervention group maintained in MAAS level (2-3) (calm, cooperative and responsive to touch). The BPS in intervention group significantly decreased following the application of SCMs than control group. Moreover, the mean duration of mechanical ventilation and length of stay in ICU were significantly shorter in the intervention group than in the control group. Conclusions: The SCMs developed, has been shown to facilitate the communication with the unconscious patients therefore, it is recommended for use in a nurse’s daily routine of unconscious patients.

Hernie pulmonaire intercostale secondaire à un effort de toux

Lung hernias are rare and their pathogenesis is few described. They are defined as the protrusion of lung parenchyma through the chest wall: intercostal space, inter-costo-clavicular, supra-clavicular or diaphragmatic hiatus. Lung hernias are classically divided into congenital and acquired hernias. Those are usually post-traumatic or post-surgical but can be provoked by cough. Clinical diagnosis is often evident but is confirmed by chest radiograph and especially computed tomography. Major risks are lung incarceration and necrosis but also ventilatory distress due to paradoxical respiration, in case of large defect. Treatment is first and foremost surgical but debated and should consider the localization, the size, the length of evolution and the possible infectious context. We report the case of a right basi-thoracic lung hernia induced by a cough fit, in a patient with chronic bronchitis.

Which preoperative respiratory evaluation?

The preoperative respiratory evaluation aims at predicting the occurrence of postoperative respiratory complications (PORC), such as: atelectasis, pulmonary infection (bronchitis and pneumonia), acute ventilatory distress, pleural effusion, prolonged mechanical ventilation, exacerbation of chronic respiratory disease and bronchospasm. The incidence of (PORC) all surgeries combined is 6.8%. Individual surgical and anesthetic factors are impacting on the occurrence of PORC. Simple scores, including anamnestic data, clinical examination and some biological parameters were validated to assess the risk of PORC depending on the type of surgery. Data from standard pulmonary function tests (PFT) is of little use to estimate the individual risk of PORC. Most of the time, PFT abnormal parameters only confirm the clinical assessment of the severity of the illness. PFT may however be useful to confirm an improvement in the clinical condition of the patient related to the preoperative preparation. Specialized EFR, including standardized testing efforts are sometimes required in the case of lung reduction surgery. These specialized explorations can predict lung function and post-interventional pulmonary oxygenation and ensure that these are viable.

Decreasing severe pain and serious adverse events while moving intensive care unit patients: a prospective interventional study (the NURSE-DO project)

IntroductionA quality-improvement project was conducted to reduce severe pain and stress-related events while moving ICU-patients.MethodsThe Plan-Do-Check-Adjust cycle was studied during four one-month phases, separated by five-month interphases. All consecutive patients staying more than 24 hours were evaluated every morning while being moved for nursing care (bathing, massage, sheet-change, repositioning). Phase 1 was considered as the baseline. Implemented and adjusted quality-interventions were assessed at phases 2 and 3, respectively. An independent post-intervention control-audit was performed at Phase 4. Primary-endpoints were the incidence of severe pain defined by a behavioral pain scale > 5 or a 0 to 10 visual numeric rating scale > 6, and the incidence of serious adverse events (SAE): cardiac arrest, arrhythmias, tachycardia, bradycardia, hypertension, hypotension, desaturation, bradypnea or ventilatory distress. Pain, SAE, patients' characteristics and analgesia were compared among the phases by a multivariate mixed-effects model for repeated-measurements, adjusted on severity index, age, admission type (medical/surgical), intubation and sedation status.ResultsDuring the four studied phases, 630 care procedures were analyzed in 53, 47, 43 and 50 patients, respectively. Incidence of severe pain decreased significantly from 16% (baseline) to 6% in Phase 3 (odds ratio (OR) = 0.33 (0.11; 0.98), P = 0.04) and 2% in Phase 4 (OR = 0.30 (0.12; 0.95), P = 0.02). Incidence of SAE decreased significantly from 37% (baseline) to 17% in Phase 3 and 21% in Phase 4. In multivariate analysis, SAE were independently associated with Phase 3 (OR = 0.40 (0.23; 0.72), P < 0.01), Phase 4 (OR = 0.53 (0.30; 0.92), P = 0.03), intubation status (OR = 1.91 (1.28; 2.85), P < 0.01) and severe pain (OR = 2.74 (1.54; 4.89), P < 0.001).ConclusionsSevere pain and serious adverse events are common and strongly associated while moving ICU patients for nursing procedures. Quality improvement of pain management is associated with a decrease of serious adverse events. Careful documentation of pain management during mobilization for nursing procedures could be implemented as a health quality indicator in the ICU.

On the pulmonary toxicity of oxygen. 5. Electronic structure and the paramagnetic property of oxygen

Oxygen uptake by the pulmonary circulation is a chemical reaction. The physicochemical attributes of oxygen are critical when studying pulmonary oxygen toxicity. Extent of lung injury depends on the percentage of oxygen in an oxygen–nitrogen mix in polybaric circumstances (Shanklin, 1969). Further change in extent of lesion follows when other gases are used in the inhalant mix instead of nitrogen (Shanklin and Lester, 1972), with oxygen at 21–100% of the mix. Comparative subatmospheric oxygen levels down to 3% in hydrogen, helium, nitrogen, argon, or sulfur hexafluoride, were run with and without ventilatory distress by the Farber (1937) model, bilateral cervical vagotomy (BCV). This yielded coherent results indicating a need to consider molecular characteristics at the atomic level. Molecular mass and size, gas viscosity, and thermal conductivity yielded no obvious correlates to lung injury. Saturation of the outer electron shells of the diluents fit the empiric data, prospectively an interaction between oxygen and nitrogen from their electronegativity and closely approximate molecular mass, size, and shape. The lesion is essentially eliminated at 7% oxygen in nitrogen. At 3% oxygen, the least lesion is found with N2, H2, and SF6, all gases with incomplete outer electron shells, allowing for transient, possibly polarized, covalent bonding with oxygen as the significant minority component in the mix. Argon and helium do not interfere with oxygen. With 3% oxygen in argon without BCV, the experiments ran so long (>70hours) they were terminated once the point had been made. 3% oxygen in argon after BCV yielded a mean survival more than twice that of BCV in air, indicating a remarkable degree of nitrogen interference with oxygen in the respiratory medium of terrestrial animal life. Argon displayed other advantages for the lung compared to nitrogen. Hydrogen, nitrogen, and oxygen are diatomic molecules, a feature which does relate to the extent of lung injury, but only oxygen is paramagnetic.Magnetic effects on lesion formation were tested: [1] with ventilatory distress induced in newborn rabbits, and [2] in young adult female white mice exposed to 100% oxygen without added mechanical distress. A noninvasive model for ventilatory distress, thoracic restraint (TR), with longer mean survivals of 40–50hours, was employed rather than the Farber model. Parallel runs with TR, one subset receiving 100% oxygen in a plastic chamber resting on six strong ring magnets with measured fields up to +1200 gauss, the other plain 100% oxygen, were performed. Both subsets developed moderate metabolic acidosis with average weight losses circa 25%, but over different time courses, 82.89±4.91hours in magnetized oxygen, 55.4% longer than the 53.34±9.82hours in plain oxygen (p<0.001). The longer survival in magnetized oxygen meant extensive lung injury (99.57±0.42% pleural surface, versus 83.86±14.03%), but the rate of lesion formation was 30.89% faster in plain oxygen (1.5722% per hour) than in magnetized oxygen (1.2012% per hour), a difference significant at p<0.001.The effect of oxygen without mechanical ventilatory distress was examined in female adult white mice exposed to oxygen or magnetized oxygen. Similar survivals and weight losses were achieved. The rate of lung lesion formation was different, 1.2617% per hour in plain oxygen, 46.13% faster than 0.8634% per hour in magnetized oxygen. A variable magnetic field, with animals moving and breathing in chambers flooded with oxygen, has both systemic and pulmonary effects which alter the rate of lesion formation due to oxygen toxicity. Paramagnetic oxygen in a magnetic field influences the effect of oxygen toxicity on the lung but at these strengths of field it does not overcome significant mechanical disturbance.

On the pulmonary toxicity of oxygen. 4. The thyroid arena

Normally developed thyroid function is critical to the transition from fetal to neonatal life with the onset of independent thermoregulation, the most conspicuous of the many ways in which thyroid secretions act throughout the body. A role for thyroid secretions in growth and maturation of the lungs as part of the preparation for the onset of breathing has been recognized for some time but how this contributes to tissue and cell processes and defenses under the duress of respiratory distress has not been well examined. Extensive archival autopsy material was searched for thyroid and adrenal weights, first by gestational age, and then for changes during the first hours after birth as ratios to body weight. After a gestational age of 22weeks the fetal thyroid and adrenal glands at autopsy in those with hyaline membrane disease are persistently half the size of those in “normal” infants dying with other disorders. When the thyroid is examined shortly after birth it reveals a post natal loss of mass per body weight of similar orders of magnitude which does not occur in the control group. A clinical sample of premature infants with (12) and without (14) hyaline membrane disease was tested for T4, TSH, TBG, and total serum protein. The results also demonstrate a special subset with lower birth weights at the same gestational age, and lower serum T4 and total serum protein. Ventilatory distress in newborn rabbits was induced by bilateral cervical vagotomy at 24h post natal following earlier injection of thyroxine (T4) or thyroid stimulating hormone (TSH) and comparisons were made with untreated animals and by dose. Early life thyroidectomy was performed followed by exposure to either air or 100% oxygen. A final experiment in air was vagotomy after thyroidectomy. Composite analysis of these methods indicates that thyroid factors are both operative and important in the newborn animal with ventilatory distress. This work and the archival data indicate those infants destined to develop hyaline membrane disease through respiratory distress are a distinct developmental and clinical subset with the point of departure from otherwise normal development and maturation in the second or early third trimester. This interval is known to be a period of marked variation in the overview indicators of fetal progress through gestational time. The initiating factor or circumstance which then separates this special subset from normal future development is placed by these observations firmly into the period when human fetal TSH dramatically rises 7-fold (17.5–25.5weeks) followed by a lesser 3 to 4-fold increase in T4 which is extended into the early third trimester. The earlier part of this interval is characterized by the thyrotrophic action of chorionic gonadotropin (hCG). The possibility that abnormalities in the intrauterine environment secondary to maternal infection play a role within this time frame is indicated by the demonstration that interleukin-2 (IL-2) induces an anterior pituitary release of TSH. Since IL-2 has this property and is not an acute phase cytokine, some form of chronic infection or an immunopathic process seems more likely as a possible active factor in pathogenesis.

Acute hypercapnic respiratory failure associated with hemodialysis

AbstractPatients undergoing hemodialysis are subject to recurrent acid‐base perturbations. Prior to each dialysis treatment, they are relatively acidemic, which is corrected rapidly during dialysis. We report a patient with obesity, obstructive lung disease, and pneumonia who developed acute respiratory failure triggered by an influx of high bicarbonate during dialysis. This case emphasizes that in patients with severely compromised respiratory reserve, a large amount of bicarbonate influx during hemodialysis may cause acute CO2 accumulation and ventilatory distress. An individualized approach with judicious adjustment of the dialysate bicarbonate concentration may be necessary. Dial. Transplant. © 2011 Wiley Periodicals, Inc.

On the pulmonary toxicity of oxygen: III. The induction of oxygen dependency by oxygen use

Oxygen is central to the development of neonatal lung injury. The increase in oxygen exposure of the neonatal lung during the onset of extrauterine air breathing is an order of magnitude, from a range of 10–12 to 110–120 Torr. The contributions of oxygen and the volume and pressure relationships of ventilatory support to lung injury are not easily distinguished in the clinical setting. Sequential changes in inspired air or 100% oxygen were studied in 536 newborn rabbits without ventilatory support. Bilateral cervical vagotomies (BCV) were performed at 24 h post natal to induce ventilatory distress which eventuates in hyaline membrane disease. The sequences applied yielded evidence for an induced state of oxygen dependency from oxygen use which was reflected in differences in survival and the extent of pulmonary injury. The median survival for animals kept in air throughout was 3 h. Oxygen before vagotomy or during the first 3 h afterwards extended the survival significantly but produced more extensive, more severe, and more rapid lung lesions. Returning animals to air after prior oxygen exposure reduced the number of survivors past 10 h and shortened the maximum survival in those groups. These features indicate the development of a dependency of the defense mechanisms on the availability of oxygen at the higher level for metabolic and possibly other aspects of the pulmonary and systemic response to injury, beyond the usual physiological need. Subset analysis revealed additive and latent effects of oxygen and demonstrated a remarkable rapidity in onset of severe lesions under some circumstances, illustrating the toxicity of oxygen per se.

Postnatal changes in the expressions of serotonin 1A, 1B, and 2A receptors in ten brain stem nuclei of the rat: implication for a sensitive period

A critical period in respiratory network development occurs in the rat around postnatal days (P) 12–13, when abrupt neurochemical, metabolic, and physiological changes were evident. As serotonin and its receptors are involved in respiratory modulation, and serotonergic abnormality is implicated in sudden infant death syndrome, we hypothesized that 5-HT receptors are significantly downregulated during the critical period. This was documented recently for 5-HT2AR in several respiratory nuclei. The present study represents a comprehensive analysis of postnatal development of 5-HT1AR and 5-HT1BR in 10 brain stem nuclei and 5-HT2AR in six nuclei not previously examined. Optical densitometric analysis of immunohistochemically-reacted neurons from P2 to P21 indicated four developmental patterns of expression: (1) Pattern I: a high level of expression at P2-P11, an abrupt and significant reduction at P12, followed by a plateau until P21 (5-HT1AR and 5-HT1BR in raphé magnus [RM], raphé obscurus [ROb], raphé pallidus [RP], pre-Bötzinger complex [PBC], nucleus ambiguus [Amb], and hypoglossal nucleus [XII; 5-HT1AR only]). (2) Pattern II: a high level at P2-P9, a gradual decline from P9 to P12, followed by a plateau until P21 (5-HT1AR and 5-HT1BR in the retrotrapezoid nucleus (RTN)/parafacial respiratory group (pFRG)). (3) Pattern III: a high level at P2-P11, followed by a gradual decline until P21 (5-HT1AR in the ventrolateral subnucleus of solitary tract nucleus [NTSVL] and the non-respiratory cuneate nucleus [CN]). (4) Pattern IV: a relatively constant level maintained from P2 to P21 (5-HT1AR in the commissural subnucleus of solitary tract nucleus (NTSCOM); 5-HT1BR in XII, NTSVL, NTSCOM, and CN; and 5-HT2AR in RM, ROb, RP, RTN/pFRG, NTSVL, and NTSCOM). Thus, a significant reduction in the expression of 5-HT1AR, 5-HT1BR, and 5-HT2AR in multiple respiratory-related nuclei at P12 is consistent with reduced serotonergic transmission during the critical period, thereby rendering the animals less able to respond adequately to ventilatory distress.

Polychondrite atrophiante : une cause possible d'extubation difficile

We report the case of a 54-year-old woman suspected of relapsing polychondritis who underwent a nasal septum biopsy under general anaesthesia. Tracheal intubation was unremarkable, but extubation attempts failed because of upper airway inspiratory collapse induced ventilatory distress. Definitive tracheostomy placement was mandatory. Cartilage biopsy confirmed severely developed relapsing polychondritis. Even though relapsing polychondritis is rare, anaesthesiologists should be aware of this pathology and preanaesthetic evaluation may focus on particular risks associated with upper airway cartilaginous structure anatomical and histological modifications.

Cutaneous innervation in Guillain-Barre syndrome: pathology and clinical correlations

Guillain-Barré syndrome (GBS) is traditionally considered to be a large-fibre neuropathy. However, the presence of hypo-aesthesia, dysaesthesia and dysautonomia in GBS patients raises the possibility that small-diameter sensory and autonomic nerves may also be affected. To investigate small-fibre neuropathy in GBS, we performed a skin biopsy from the distal leg of 20 patients with the demyelinating form of GBS. Skin sections were immunohistochemically stained with antiserum against protein gene product 9.5 (PGP 9.5), a ubiquitin C-terminal hydrolase. Cutaneous innervation was evaluated by measuring epidermal nerve density (END), and END was further correlated with various clinical and electrophysiological parameters. In GBS patients, END values were much lower than in age- and gender-matched control subjects (5.03 +/- 1.18 versus 10.16 +/- 0.87 fibres/mm, P < 0.001). Eleven patients (55%) had reduced epidermal innervation with pathological evidence of active nerve degeneration in the dermis: fragmentation of subepidermal nerve plexuses and a beaded appearance of dermal nerves. GBS patients had significantly elevated thermal thresholds with higher warm threshold temperatures (44.54 +/- 1.04 versus 39.00 +/- 0.35 degrees C, P < 0.001) and lower cold threshold temperatures (25.57 +/- 1.11 versus 29.05 +/- 0.21 degrees C, P = 0.032). Reduced END values were associated with an elevated warm threshold (P = 0.027), ventilatory distress (P = 0.037) and dysautonomia (P = 0.001). END values were negatively correlated with disability grade on a scale of 1-6 (slope -0.134 +/- 0.038, P = 0.0018). Patients with reduced END values tended to have a slower recovery than those with normal END values (P = 0.013, median time 12 versus 2 weeks). Patho logically, sudomotor innervation of the skin was reduced in five of 17 (29.4%) GBS patients in whom sweat glands could be recognized. These findings suggest that small-fibre sensory and autonomic neuropathies exist in a significant proportion of GBS patients, and that END values are correlated with functional disabilities. In summary, GBS should be considered a global neuropathy instead of a pure large-fibre neuropathy.

Pediatric tracheotomy: is postoperative chest X-ray necessary?

A retrospective study of 101 children who underwent tracheotomy at the Children's Hospital of Pittsburgh from 1993 to 1996 was performed. The following criteria were reviewed in each patient: age, gender, race, prematurity, weight during tracheotomy, presence of preoperative airway support, duration of tracheotomy, nature (emergent versus elective), tracheotomy tube size, reason for tracheotomy, accompanying medical diagnoses, chest x-ray (CXR) findings, surgical service, postoperative symptoms (up to 3 days), and operative mortality rate. Of these criteria, our results show that CXR-screenable complications occurred in patients who underwent emergent recannulation, as well as those who exhibited ventilatory distress (oxygen saturation level of <90%) and specific changes in postoperative symptoms. Pneumothorax developed after tracheotomy in 3 of the 101 patients; each had one of these risk factors. We conclude that CXR of all pediatric patients after tracheotomy may be unnecessary with the use of flexible endoscopy and screening restrictions that are both health-conscious and cost-effective.

Amyotrophic lateral sclerosis and pregnancy

We describe the first case of pregnancy in a patient with amyotrophic lateral sclerosis (ALS) reported in Uruguay. The 27-year-old white woman who came to our clinic complaining of general weakness and gait symptoms was diagnosed as being pregnant and met the El Escorial criteria of probable ALS. The advised abortion caused her to abandon medical treatment, which was only resumed after a period of severe deterioration, at 32 weeks of gestation. After several days of serious vital risk, as evaluated by a multidisciplinary team, a normal male baby was born. Four months later, the patient had gradually improved and reached a stable condition, but presented with restrictive ventilatory distress.

The influence of upper respiratory tract surgery on respiratory function evaluated by oxygen saturation.

To evaluate the influence of upper respiratory tract surgery on respiratory function, we used a pulse oximeter to measure the arterial oxygen saturation in 40 patients (ASA 1 or 2) during surgery under local anesthesia. The patients were divided into four groups: a control group of 10 patients who underwent surgery not involving the upper respiratory tract, and three upper respiratory tract surgery groups of 10 patients each underwent surgery on the nasal cavity alone (group 1), on the oral cavity alone (group 2), and on both the oral and nasal cavities (group 3). Groups 1 and 2 showed little desaturation compared to their baseline levels and the control group, while group 3 showed a mild desaturation even at the beginning of surgery and this gradually turned to a moderate or severe desaturation. This was due to both the extension of the surgical zone to the nasal and oral cavities and to ventilatory distress produced by massive bleeding and aspiration of secretions. Thus, the pulse oximeter is a useful monitor for upper respiratory tract surgery involving both general and local anesthesia. It allows the identification of hypoxia so that remedial therapy can be instituted.

Tracheotomy: A Clinical and Experimental Study

This little book is the most comprehensive treatise on all of the aspects of tracheotomy the reviewer has yet come across. Its bibliography alone comprises 293 references. It deals with nearly every type of ventilatory distress, and in addition to a standard section on the classic indications for tracheotomy from the mechanical point of view, it approaches the problem from the physiologic viewpoint with an up-to-date discussion of the syndrome of secretional ventilatory obstruction. After a very complete and interesting historical review of this ancient operative procedure, the author tabulates in various forms a series of 310 tracheotomies performed on 300 patients at the Brooke Army Hospital, Fort Sam Houston, Texas from 1947 to 1955.

The Importance of Tracheostomy in Acute Ventilatory Distress

The Importance of Tracheostomy in Acute Ventilatory Distress