Ma Carmen Unzueta

Hospital de Sant Pau

Author Statistics

Papers

Citation

H-Index

i-10 index

Research Trends

Author Order

Document Type

Co-Authors

César Hervás‐Martínez

University of Córdoba

Alfred Merten

Hospital de Sant Pau

Marina Soro

Hospital Clínico Universitario de Valencia

Ignacio Garutti

Hospital General Universitario Gregorio Marañón

Aurélio Rodriguez

Hospital Universitario de Gran Canaria Doctor Negrín

Lucía Gallego

Universidad Complutense de Madrid

Ignacio Casas

Complejo Hospitalario de Cáceres

F. Ramasco

Hospital Universitario de La Princesa

Carlos Ferrando

Instituto de Salud Carlos III

Julián Librero

Navarrabiomed

Cooperative Institutions

Hospital Clínico Universitario de Valencia

Instituto de Salud Carlos III

Hospital Universitari i Politècnic La Fe

Hospital Clínic de Barcelona

Universitat de València

Universitat de Barcelona

Hospital Universitario de La Princesa

INCLIVA Health Research Institute

Complejo Hospitalario de Pontevedra

Hospital de Sant Pau

Author Statistics

Papers

Citation

H-Index

i-10 index

Research Field

Jose Miguel Martinez: Spanish pioneer of the specialization of anesthesiology

International Congress Series (2002)

César Hervás‐Martínez Ma Carmen Unzueta Enrique Ortega de Miguel

Drug overdose

Opioid Overdose

10.1016/s0531-5131(02)00707-0

Cite

Citations (0)

Oxygen in the works of three Spanish enlightened scientist: Ignacio Ma Ruiz de Luzuriaga, Antoni Martı́ i Franqués and Antoni Cibat

International Congress Series (2002)

César Hervás‐Martínez Ma Carmen Unzueta

Crossover study

Mean difference

10.1016/s0531-5131(02)00725-2

Cite

Citations (0)

Rationale and study design for an individualized perioperative open lung ventilatory strategy (iPROVE): study protocol for a randomized controlled trial

Trials (2015)

Carlos Ferrando Marina Soro Jaume Canet Ma Carmen Unzueta Fernando Suárez

Postoperative pulmonary and non-pulmonary complications are common problems that increase morbidity and mortality in surgical patients, even though the incidence has decreased with the increased use of protective lung ventilation strategies. Previous trials have focused on standard strategies in the intraoperative or postoperative period, but without personalizing these strategies to suit the needs of each individual patient and without considering both these periods as a global perioperative lung-protective approach. The trial presented here aims at comparing postoperative complications when using an individualized ventilatory management strategy in the intraoperative and immediate postoperative periods with those when using a standard protective ventilation strategy in patients scheduled for major abdominal surgery.

10.1186/s13063-015-0694-1

Cite

Citations (41)

Endobronchial High-Frequency Jet Ventilation for Endobronchial Laser Surgery: An Alternative Approach

Anesthesia & Analgesia (2003)

Ma Carmen Unzueta Ignacio Casas Alfred Merten Manuel J. V. Landeira

High-frequency jet ventilation (HFJV) is an effective ventilatory method that provides adequate pulmonary gas exchange. In cases of endobronchial laser surgery, it has been delivered through the sidearm of the bronchoscope or via a small catheter placed either in the trachea or in the mainstem bronchus (1–3). One of the potential risks of this technique is to cause barotrauma if airway pressures are not monitored. We report an alternative approach for endobronchial HFJV with continuous measurement of airway pressures, that achieves satisfactory operating conditions and contributes to the prevention of barotrauma. Materials and Methods After obtaining approval from the ethics committee and informed consent, 5 patients were included in this study (4 men and 1 woman), age range 50–80 (mean 60) yr. The endobronchial location of the lesions and preoperative lung function tests are shown in Table 1.Table 1: Preoperative Lung Function DataAnesthesia was induced with propofol (2 mg/kg), a single dose of fentanyl (0.1 mg), and rocuronium (0.6 mg/kg). Anesthesia was maintained with propofol infusion (6 mg · kg−1 · h−1) titrated to keep systolic blood pressure and heart rate (HR) within 20% of preinduction values, and with intermittent dosages of rocuronium. Tracheas were intubated orally with a thin Teflon catheter with an internal diameter of 2.2 mm and a length of 30 cm (injector catheter). This catheter was advanced selectively into the main bronchus opposite to the tumor with the tip positioned 2 cm distal to the carina. HFJV was provided by using a Temel-Ergojet CVT anesthesia ventilator. Preset respiratory variables were: frequency 100 breaths/min, inspiratory time 40%, driving gas pressure 35–42 psi (1837–2205 mm Hg), and oxygen inspired fraction (Fio2) 0.8. As soon as electrocoagulation was started, the Fio2 was decreased to 0.4 to reduce the risk of airway fire. The upper airway pressure limit was set at 20 cm H2O. To ensure an adequate exhaust of expired gas while the rigid bronchoscope was introduced, a Mayo cannula was used. In addition to the injector catheter, a second identical one, only 7-cm longer, was inserted to measure airway pressures (Paw catheter). The tip of this catheter was placed 7 cm further distal to the tip of the injector catheter to avoid interference during the measurement of pressures. This catheter was connected to the Ergojet ventilator continuously monitoring the maximal, mid, and minimal airway pressures. This allowed us to register electronically the peak inspiratory pressure (Paw max), the mid pressures (Paw mid), which reflect the true mean airway pressure, and also the minimal airway pressure (Paw min), which gives some idea of the direction of variation of gas trapping (induced positive end-expiratory pressure effect). The correct position of both catheters was checked via the fiberoptic bronchoscope, as well as possible lacerations on the bronchial or tracheal mucosa. Arterial blood gases were drawn after 15 min of the beginning of HFJV with an Fio2 of 0.8 and again after 30 min, having decreased the Fio2 to 0.4 for at least 15 min. Results The mean duration of surgery was 62.6 (range, 50–75) min, and the mean duration of jet ventilation was 43 (range, 30–75) min. During the placement of the rigid bronchoscope, no interference with the injector catheter occurred, and therefore the ventilation did not need to be discontinued. Patients remained hemodynamically stable during the whole procedure, with systolic arterial blood pressure and HR within normal limits (systolic arterial blood pressure 133.6 ± 3.1 mm Hg, HR 89.9 ± 2.8 bpm). Mean airway pressures (maximal, mid, and minimal) were within normal ranges (Table 2). Neither hemodynamic nor respiratory complications were recorded. During one-lung HFJV, the Pao2 and the Paco2 maintained within acceptable limits, even when the Fio2 was reduced to 0.4, although a slight tendency toward increased CO2 concentrations was observed in longer surgical procedures.Table 2: Minimal, Mid, and Maximal Registered Airway Pressures (Paw), Blood Gases, and Jet Volume Delivered by the Respirator During One-Lung HFJV at Preset Respiratory Variables (Respiratory Rate 100 rpm, Driving Pressure 35–42 psi, Inspiratory Time 40%)At the end of the procedure, the fibrobronchoscopic control of the tracheal or bronchial mucosa did not reveal any lesions. All patients had satisfactory spontaneous breathing. They were admitted to the postoperative care unit where a chest film was taken and 2 h later they were discharged to the ward. Discussion Anesthesia for endobronchial surgery through a rigid bronchoscope can be technically difficult. The occupation of the upper airway by the bronchoscope makes it necessary to use ventilatory methods that are not used routinely. HFJV is an accepted alternative method for ventilation during endobronchial procedures. When HFJV is used for endobronchial procedures, the injector catheter is usually placed in the trachea in order to use the ventilatory capacity of the affected lung. However, HFJV can also be delivered by placing the injector catheter into the mainstem bronchus opposite to the lesion (3). We describe a modified technique of HFJV of the nonaffected lung using two joined catheters. One catheter is used to insufflate the gas (injector catheter) and the other allows the continuous measurement of the pressures in the airway to avoid barotrauma, which is one of the obvious risks of this technique (1,4,5). The use of the second lumen of a double-lumen catheter to monitor the pressures has already been described. In these studies, the pressures were measured either proximally to the injecting catheter or very close to it and therefore their values were respectively altered because of the Bernoulli principle and because of the turbulence of the jet stream (6–9). Because the pressure values during HFJV depend on the point of measurement within the airway, it has been suggested that they must be measured several centimeters further distal to the tip of the injecting catheter (4,10). In our study, the Paw catheter, with its distal end 7-cm further distal from the tip of the injector catheter, allowed us to register the maximal, mid, and minimal airway pressures during the whole procedure. The obtained pressure values were always kept in an acceptable range (Paw max range: 2–10, Paw mid range: 2–6, Paw min range: 1–4) during surgery, suggesting that there was neither hyperpressure nor increased air trapping (10). Therefore, the surgical procedure could be performed without having to interrupt the ventilation at any moment, and no respiratory complications were observed. We used narrow catheters (internal diameter 2.2 mm), which allow the introduction of a rigid bronchoscope without problem, because there is enough space around them. The catheters are not compressed by the bronchoscope, and therefore the ventilation does not need to be interrupted during the procedure. The expiration is also not compromised because it is through the lumen of the bronchoscope and its surroundings. Other authors have used wider catheters (4.7 mm, 4.4 mm), but this diameter may be too wide to maintain the characteristics of the gas stream with HFJV (2,3). One of the major risks of HFJV is the occurrence of barotrauma (1,4). With the described technique, the risk of hyperpressure is minimized, because of the continuous registration of the insufflation pressures in the bronchial system and also because of the availability of a double security system in the respirator that automatically cuts off the ventilator at a preset airway pressure level. To avoid barotrauma, not only must excessive hyperinsufflation be avoided, but there must be adequate expiration of ventilatory gases. Although barotrauma is one of the major concerns using HFJV for laser surgery, other problems, such as contamination, ignition, or venous gas embolism, need to be considered. With this technique, the injector catheter is placed into the bronchus contralateral to the lesion, avoiding interference between ventilation and surgical removal as they take place in different lungs. Therefore, the risk of bronchial blockage of the ventilated lung by resected material is reduced and contamination by laser smoke is less, because the high expiratory flow favors the drainage of smoke outward (6). Because the laser is used in the nonventilated lung, the risk of ignition of the airway is also reduced compared with ventilation through a tube placed in the trachea. If accidental pulmonary vein damage should occur because of the laser treatment, as the ventilation takes place in the contralateral lung, the air will not pass directly into the damaged pulmonary venous system and therefore the theoretical risk of gas embolism is reduced (11). Another theoretical risk of this technique is the laceration of the airway mucosa because of the direct contact of the high-pressure jet with the tracheal or bronchial wall and the subsequent injection of gas into the submucosa (12). We observed with the fibrobronchoscope that once the catheter was placed in the bronchus, the “whip” movement of the catheter was nearly abolished. No lesions of the mucosa, neither after the introduction of the catheter nor after its removal, were detected. In our study, all patients tolerated well the one-lung HFJV, even when the Fio2 was reduced to 0.4. During HFJV, hypercapnia is often observed (2). The Paco2 values were kept between acceptable ranges, and only in one case did the Paco2 exceed 50 mm Hg. Although the number of cases included in this study is small, our results suggest that endobronchial HFJV of the nonaffected lung with a small catheter with continuous monitoring of airway pressures achieves satisfactory operating conditions and may offer a practical alternative form of ventilation which contributes to the prevention of barotrauma. The authors thank Mr. Francesc Fontana, bioengineering technician, for his help and technical assistance.

Jet ventilation

Tracheal tube

Peak inspiratory pressure

10.1213/00000539-200301000-00059

Cite

Citations (7)

Study of the influence of a lung recruitment strategy on oxygenation, lung mechanics and dead-space in thoracic surgery

Ma Carmen Unzueta

Dead space

Respiratory physiology

Cardiothoracic surgery

10.1186/isrctn94238623

Cite

Citations (0)

Aumento de presión en la vía aérea durante la ventilación mecánica: más allá del broncoespasmo

Revista Española de Anestesiología y Reanimación (2011)

P. Rama‐Maceiras Ma Carmen Unzueta Marina Soro R. González de Castro J. Belda

10.1016/s0034-9356(11)70002-0

Cite

Citations (0)

Rationale and Study Design for an Individualized Perioperative Open Lung Ventilatory Strategy in Patients on One-Lung Ventilation (iPROVE-OLV)

Journal of Cardiothoracic and Vascular Anesthesia (2019)

Albert Carramiñana Carlos Ferrando Ma Carmen Unzueta Ricard Navarro Fernando Suárez-Sipmann

Atelectasis

Cardiothoracic surgery

Nasal cannula

10.1053/j.jvca.2019.01.056

Cite

Citations (25)

Robert Macintosh and the Spanish Civil War: a new perspective

International Congress Series (2002)

César Hervás‐Martínez Ma Carmen Unzueta

Simplicity

Software portability

10.1016/s0531-5131(02)00710-0

Cite

Citations (2)

Endobronchial High-Frequency Jet Ventilation for Endobronchial Laser Surgery: An Alternative Approach

Anesthesia & Analgesia (2003)

Ma Carmen Unzueta Ignacio Casas Alfred Merten J M Villar Landeira

We describe a technique of one-lung high-frequency jet ventilation surgery with continuous monitoring of airway pressures that achieves satisfactory operating conditions with less complications than other similar approaches.

Jet ventilation

High-frequency ventilation

10.1097/00000539-200301000-00059

Cite

Citations (6)

Macintosh's Laryngoscope

Anesthesiology (2004)

Ma Carmen Unzueta J Ignacio Casas Alfred Merten

We have read the paper of Burkle et al. regarding the history of the laryngoscope in anesthesia1with great interest. The authors give a very good historical perspective of the different types of laryngoscope. Nevertheless we would like to highlight the laryngoscope designed by Robert Macintosh in 1943 because of its importance and significance.2In our opinion, the Macintosh blade is much more than a variant of the models previously mentioned, as it allowed a better view of the vocal cords, making the tracheal intubation easier.Sir Robert Reynolds Macintosh was the first professor of Anesthesia at Oxford University, which was the first chair of anesthesia in Europe.3,4The laryngoscope designed by Macintosh is probably the most successful and lasting instrument in the history of anesthesia; it has survived plastic translation and the adoption of fiber light. The laryngoscope was designed to lessen the difficulty of exposing the larynx by direct elevation of the epiglottis, as the blades existing at that time did not allow correct visualization of the vocal cords.2This becomes evident in a letter that Sir Robert Macintosh wrote to Jephcott in which he also explained how he got the idea to design a new laryngoscope:5“The ability to pass the endotracheal tube under direct vision was the hallmark of the successful anesthetist. Magill was outstanding in this respect. I described a new approach in 1941 but it was not much of an improvement.6The difficulty was to expose the cords. Then, one morning during a tonsillectomy list, I had a bit of luck and the nous to take advantage of it. On opening a patient's mouth with a Boyle-Davis gag, I found the cord perfectly displayed. Richard Salt (a really excellent chap) was in the theater with me; before the morning had finished he has gone out and soldered a Davis blade on to the laryngoscope handle and this functioned quite adequately as a laryngoscope. The important pint being that the tip finishes up proximal to the epiglottis. The curve, although convenient when intubating with naturally curved tubes, is not of primary importance as I emphasized subsequently.”Although, as manifested in this letter, Sir Robert Macintosh did not consider the shape or curve of the blade of primary importance, the use of a curved blade may often avoid jeopardizing the patient's upper teeth, as it makes it unnecessary to pass the straight blade of the standard laryngoscope beyond the epiglottis.7We consider that in an historical review about laryngoscope, the one designed by Sir Robert Macintosh in 1943, which is still nowadays the most common currently used blade, deserves a bit more mention, as it not only lessens the chance of damage of the patient's upper teeth but also allows a correct visualization of the vocal cords, which was sometimes more difficult with the previously existing models.* Hospital de Sant Pau, Barcelona, Spain. mcunzueta@telefonica.net

10.1097/00000542-200501000-00046

Cite

Citations (9)