Airway injury from the presence of endotracheal tubes and the association with subglottic secretion drainage: a prospective observational study.

PURPOSE: Laryngeal and tracheal injuries are known complications of endotracheal intubation. Endotracheal tubes (ETTs) with subglottic suction devices (SSDs) are commonly used in the critical care setting. There is concern that herniation of tissue into the suction port of these devices may lead to tracheal injury resulting in serious clinical consequences such as tracheal stenosis. We aimed to describe the type and location of tracheal injuries seen in intubated critically ill patients and assess injuries at the suction port as well as in-hospital complications associated with those injuries. METHODS: We conducted a prospective observational study of 57 critically ill patients admitted to a level 3 intensive care unit who were endotracheally intubated and underwent percutaneous tracheostomy. Investigators performed bronchoscopy and photographic evaluation of the airway during the percutaneous tracheostomy procedure to evaluate tracheal and laryngeal injury. RESULTS: Forty-one (72%) patients intubated with ETT with SSD and sixteen (28%) patients with standard ETT were included in the study. Forty-seven (83%) patients had a documented airway injury ranging from hyperemia to deep ulceration of the mucosa. A common tracheal injury was at the site of the tracheal cuff. Injury at the site of the subglottic suction device was seen in 5/41 (12%) patients. There were no in-hospital complications. CONCLUSIONS: Airway injury was common in critically ill patients following endotracheal intubation, and tracheal injury commonly occurred at the site of the endotracheal cuff. Injury occurred at the site of the subglottic suction port in some patients although the clinical consequences of these injuries remain unclear.

RéSUMé: OBJECTIF: Les lésions laryngées et trachéales sont des complications connues de l'intubation endotrachéale. Les sondes endotrachéales (SET) avec dispositifs d'aspiration sous-glottiques (DASG) sont couramment utilisées aux soins intensifs. On craint qu'une hernie tissulaire dans l'orifice d'aspiration de ces dispositifs n'entraîne des lésions trachéales, résultant en de graves conséquences cliniques telles qu'une sténose trachéale. Nous avons cherché à décrire le type et l'emplacement des lésions trachéales observées chez les patients gravement malades intubés et à évaluer les lésions au port d'aspiration ainsi que les complications hospitalières associées à ces lésions. MéTHODE: Nous avons mené une étude observationnelle prospective auprès de 57 patients gravement malades admis dans une unité de soins intensifs de niveau 3 qui ont été intubés par voie endotrachéale et ont subi une trachéostomie percutanée. Les chercheurs ont réalisé une bronchoscopie et une évaluation photographique des voies aériennes au cours de la trachéostomie percutanée afin d'évaluer les lésions trachéales et laryngées. RéSULTATS: Quarante et un (72 %) intubés par SET avec DASG et seize (28 %) patients avec SET standard ont été inclus dans l'étude. Quarante-sept (83 %) patients ont présenté une lésion documentée des voies aériennes allant de l'hyperémie à l'ulcération profonde de la muqueuse. Une lésion trachéale commune était localisée sur le site du ballonnet trachéal. Une lésion au site du dispositif d'aspiration sous-glottique a été observée chez 5/41 (12 %) patients. Il n'y a pas eu de complications à l'hôpital. CONCLUSION: Les lésions des voies aériennes étaient fréquentes chez les patients gravement malades après une intubation endotrachéale, et les lésions trachéales se produisaient généralement au site du ballonnet endotrachéal. Des lésions se sont produites au site de l'orifice d'aspiration sous-glottique chez certains patients, bien que les conséquences cliniques de ces lésions restent incertaines.

Is faster still better in therapeutic hypothermia?

The rapid institution of therapeutic hypothermia after cardiac arrest has become an accepted practice. In the previous issue of Critical Care, Haugk and colleagues present a retrospective analysis of 13 years of experience with therapeutic hypothermia at their center that suggests an association between rate of cooling and less favorable neurological outcomes. The association most likely reflects easier cooling in patients more severely brain injured by their initial cardiac arrest, and should not lead clinicians to abandon or slow their efforts to achieve post-resuscitative cooling.

A comparative evaluation of capnometry versus pulse oximetry during procedural sedation and analgesia on room air.

OBJECTIVE: Important questions remain regarding how best to monitor patients during procedural sedation and analgesia (PSA). Capnometry can detect hypoventilation and apnea, yet it is rarely used in emergency patients. Even the routine practice of performing preoxygenation in low-risk patients is controversial, as supplementary oxygen can delay the detection of respiratory depression by pulse oximetry. The purpose of this study was to determine whether the capnometer or the pulse oximeter would first detect respiratory events in adults breathing room air. METHODS: During a randomized clinical trial comparing fentanyl with low-dose ketamine for PSA with titrated propofol, patients were monitored using pulse oximetry and continuous oral-nasal sampled capnography. Supplemental oxygen was administered only for oxygen desaturation. Sedating physicians identified prespecified respiratory events, including hypoventilation (end-tidal carbon dioxide > 50 mm Hg, rise of 10 mm Hg from baseline or loss of waveform) and oxygen desaturation (pulse oximetry < 92%). These events and their timing were corroborated by memory data retrieved from the monitors. RESULTS: Of 63 patients enrolled, 57% (36) developed brief oxygen desaturation at some point during the sedation. All responded to oxygen, stimulation or interruption of propofol. Measurements of end-tidal carbon dioxide varied substantially between and within patients before study intervention. Hypoventilation (19 patients, 30%) was only weakly associated with oxygen desaturation (crude odds ratio 1.4 [95% confidence interval 0.47 to 4.3]), and preceded oxygen desaturation in none of the 12 patients in whom both events occurred (median lag 1:50 m:ss [interquartile range 0:01 to 3:24 m:ss]). CONCLUSION: During PSA in adults breathing room air, desaturation detectable by pulse oximeter usually occurs before overt changes in capnometry are identified.

Subdissociative-dose ketamine versus fentanyl for analgesia during propofol procedural sedation: a randomized clinical trial.

OBJECTIVES: The authors sought to compare the safety and efficacy of subdissociative-dose ketamine versus fentanyl as adjunct analgesics for emergency department (ED) procedural sedation and analgesia (PSA) with propofol. METHODS: This double-blind, randomized trial enrolled American Society of Anesthesiology (ASA) Class I or II ED patients, aged 14-65 years, requiring PSA for orthopedic reduction or abscess drainage. Subjects received 0.3 mg/kg ketamine or 1.5 mug/kg fentanyl intravenously (IV), followed by IV propofol titrated to deep sedation. Supplemental oxygen was not routinely administered. The primary outcomes were the frequency and severity of cardiorespiratory events and interventions, rated using a composite intrasedation event rating scale. Secondary outcomes included the frequency of specific scale component events, propofol doses required to achieve and maintain sedation, times to sedation and recovery, and physician and patient satisfaction. RESULTS: Sixty-three patients were enrolled. Of patients who received fentanyl, 26/31 (83.9%) had an intrasedation event versus 15/32 (46.9%) of those who received ketamine. Events prospectively rated as moderate or severe were seen in 16/31 (51.6%) of fentanyl subjects versus 7/32 (21.9%) of ketamine subjects. Patients receiving fentanyl had 5.1 (95% confidence interval [CI] = 1.9 to 13.6; p < 0.001) times the odds of having a more serious intrasedation event rating than patients receiving ketamine. There were no significant differences in secondary outcomes, apart from higher propofol doses in the ketamine arm. CONCLUSIONS: Subdissociative-dose ketamine is safer than fentanyl for ED PSA with propofol and appears to have similar efficacy.

Derivation of a termination-of-resuscitation guideline for emergency medical technicians using automated external defibrillators.

OBJECTIVES: To determine the association between characteristics of cardiac arrest and survival to hospital discharge following failed resuscitation by defibrillation-trained emergency medical technicians (EMT-Ds), and to propose an out-of-hospital termination-of-resuscitation (TOR) guideline for EMT-Ds. METHODS: A 22-month retrospective review of 700 out-of-hospital primary cardiac arrest patients in a large emergency medical services (EMS) system who received exclusively EMT-D care. RESULTS: Seven hundred primary cardiac arrest patients were identified. Follow-up was obtained in 662 cases (94.6%). Of these, 36 (5.4%) achieved a return of spontaneous circulation (ROSC) prior to transport. Among the 626 patients who failed to achieve ROSC at any time, two (0.3%) survived to discharge. Multivariate analysis showed that ROSC at any time had the strongest association with survival [odds ratio (OR) 45.5; 95% confidence interval (95% CI) = 8.5 to 243.7]. A shock prior to transport (OR 6.9; 95% CI = 1.2 to 40.3) and cardiac arrest witnessed by EMS personnel (OR 4.4; 95% CI = 1.0 to 18.5) were also independently associated with survival. These variables were incorporated into a TOR guideline. The guideline was 100% sensitive (95% CI = 99.1 to 100) in identifying survivors and had 100% negative predictive value (95% CI = 75.3 to 100) for identifying nonsurvivors of out-of-hospital cardiac arrest in the study population. CONCLUSIONS: In this EMS system, cardiac arrest patients may be considered for out-of-hospital TOR following EMT-D resuscitation attempts when there has been no ROSC, no shock has been given, and the arrest was not witnessed by EMS personnel. These guidelines require prospective validation.