Study Design

Reduced Quality Factors

0 = no serious, - = serious,

- - = very serious

Positive Quality Factors

0 = none, + = one, ++ = multiple

Dichotomous Outcome Summary

Non-Dichotomous Outcome Summary

Brief description

Overall Quality

High, moderate, low,
very low, none

No of studies

Study Type

RoB

Indirectness

Imprecision

Inconsistency

Large Effect

Dose-Response

Confounder

# Intervention with Outcome

# Control with Outcome

RR (95% CI)

Outcome: Favorable neurologic outcome

1

CT

--

-

0

0

0

0

0

Very low

Outcome: Survival to discharge

4

CT

-

-

0

0

0

0

0

Low

1

OS

--

-

-

0

+

0

0

Very low

Outcome: Complications

4

CT

-

-

-

0

0

0

0

Very low

1

ES

--

-

-

0

0

0

0

Very low

1

OS

--

-

-

0

0

0

0

Very low

Outcome: Increase in heart rate

5

CT

-

-

0

0

0

0

0

Low

1

OS

--

-

-

0

0

0

0

Very low

Outcome: Hospital length of stay

3

CT

-

--

-

0

0

0

0

Very low

Introduction

Aeration of airways and lungs is a central event in the transition from intrauterine to extrauterine life. Historically, in people, oronasopharyngeal suctioning (ONPS) was used to help remove oral and nasal secretions of vigorous newborn infants born through clear amniotic fluid. In addition, endotracheal suctioning (ETS) was recommended in non-vigorous newborn infants born through meconium-stained amniotic fluid (Bloom 1994, Niedermeyer 2000). Based on an evolving body of evidence, newborn resuscitation guidelines in people now de-emphasize routine ONPS and recommend against routine ETS but shifted toward early support of ventilation with PPV (Wyckoff 2020, Wyckoff 2015). Of note, ETS in newborn infants necessitates endotracheal intubation. Like infants at birth, newborn puppies and kittens may have either clear or meconium-stained secretions of variable quantity in the upper airways, particularly the nasal passages and oropharynx. Veterinarians have employed a variety of techniques, including the use of bulb syringes or suction catheters, to remove upper airway secretions (Davidson 2014). This question addresses whether there is a need for routine ONPS or ETS in newborn puppies and kittens.

Consensus on science

Outcome 1: Favorable neurologic outcome

For the most critical outcome of favorable neurologic outcome, we identified 1 clinical trial in newborn infants (very low quality of evidence, downgraded for very serious risk of bias and serious indirectness). (Chettri 2015/paper 563) In this study, including 122 non-vigorous, term, newborns born through meconium-stained fluid, ETS did not impact neurodevelopmental outcome at 9 months among the 86 infants still alive at that time. (Chettri 2015/paper 563) No studies examining this outcome after ONPS were identified.

Outcome 2: Survival to discharge

For the next critical outcome of survival to discharge, 4 clinical trials (low quality of evidence, downgraded for serious risk of bias and serious indirectness) and 1 observational study (very low quality of evidence, downgraded for very serious risk of bias, serious indirectness, and imprecision), all in a human healthcare setting, were identified.( Chettri 2015/paper 563, Nangia 2016/paper 1346, Kumar 2019/paper 558, Ting 1975/paper 1342, Vain 2004) Only one study evaluated ONPS without ETS, a multicenter RCT including 2514 term newborns, born by vaginal birth or C-section and through meconium stained amniotic fluid.( Vain 2004) Nine newborns in the ONPS group and 4 in the control group died (RR, 0.8; 95% CI 0.1-1.5). All other studies concerned ETS. The clinical trials demonstrated no significant survival benefit in non-vigorous newborns born through meconium-stained amniotic fluid receiving ETS.( Chettri 2015/paper 563, Nangia 2016/paper 1346, Kumar 2019/paper 558) Chettri and colleagues reported in their study (n=61 per study arm) a 16% mortality rate at 9-months in the ETS group versus 20% mortality in the control group (P = 0.82).( Chettri, 2015) Nangia et al. randomized 88 newborns to no suctioning and 88 to ETS, with the mortality being 4.6% and 10.3%, respectively (OR, 0.4; 95% CI 0.12-1.4; P = 0.14).( Nangia, 2016) Likewise, Kumar et al found similar risk of death in those newborns treated with ETS versus those not (RR, 1.8; 95% CI 0.6 – 3.4) and mortalities of 13.6% and 7.5%, respectively.( Kumar, 2019) In contrast, 1 small (n=125), single center, retrospective observational study published in 1975, showed an association between immediate tracheal suction in infants born through meconium-stained amniotic fluid and a reduction in morbidity and mortality. (Ting 1975/paper 1342). Seven of 28 newborns that did not receive ETS died, while only 1 of 97 newborns receiving ETS died (P < 0.001).

Outcome 3: Complications

For the important outcome of complications, we found 4 clinical trials of which 1 was in newborn puppies (low quality of evidence, downgraded for serious risk of bias, serious indirectness, and imprecision), 1 observational study in people (very low quality of evidence, downgraded for very serious risk of bias, serious indirectness, and imprecision), and 1 experimental study in lambs (very low quality of evidence, downgraded for very serious risk of bias, serious indirectness, and imprecision) that addressed the PICO question.( Goericke-Pesch 2012/paper 549, Chettri 2015/paper 563, Nangia 2016/paper 1346, Kumar 2019/paper 558, Viraraghavan 2018/paper 1339, Lakshminrusimha 2015/paper 556). Most studies reporting this outcome concerned the intervention of ETS. Three clinical trials in newborn infants documented no difference in complication rate in infants born through meconium-stained amniotic fluid regardless of whether ETS was applied or not (Chettri 2015/paper 563, Nangia 2016/paper 1346, Kumar 2019/paper 558). In an experimental lamb study, Lakshminrusimha et al. evaluated the effects of ETS at birth in asphyxiated newborn lambs with meconium aspiration (Lakshminrusimha 2015/paper 556). Lambs that underwent ETS (n=15) did receive PPV significantly later (146±11 s) compared to animals not undergoing ETS (n=14, 47±3 s, P < 0.001) and experienced lower HRs during suctioning with 3 animals proceeding to cardiopulmonary arrest requiring resuscitation. We identified 2 studies that reported complications with nasal suctioning or ONPS. Goericke-Pesch et al. evaluated puppies delivered by C-section randomly allocated to suction of the nostril by either a 1 mL syringe with suction tip (n=78), or by suction bulb (n=93).( Goericke-Pesch 2012/paper 549) A small percentage (6.5%) of animals in which the syringe was used but none in the suction bulb group showed minor bleeding from the nostrils. A single observations study including term newborn infants born by C-section through clear amniotic fluid did not identify a higher incidence in bradycardia or apnea associated with ONPS (n=36) when compared to a control group with no such suctioning (n=36).( Pocivalnik 2015)

Outcome 4: Increase in heart rate

For the important outcome of increase in HR, we identified 5 clinical trials in newborn infants that all concerned ONPS (low quality of evidence, downgraded for serious risk of bias and serious indirectness). (Waltman 2004/paper 577, Gungor 2005, Gungor 2006/paper 578, Bancalari 2019, Modarres 2014). Waltman et al. examined in a small RCT pilot study (n=10 per treatment arm) the effects of bulb suctioning in healthy term newborn infants. While a statistically significantly higher HR emerged in newborns without ONPS during the first 20 minutes after birth (difference, 11±5 bpm, P=0.042), the HR measurements in both groups were within normal range.( Waltman 2004/paper 577). In contrast, Gungor et al showed that in healthy, term newborn infants born through clear amniotic fluid (n=70 per treatment arm), ONPS led to a significantly higher HR from the 3rd minute after birth onward (131.7±4.4 beats/min) compared to those without ONPS (127.3±6.8 beats/min, P<0.001), although this difference is of uncertain clinical significance.( Gungor 2005) In a follow-up study by the same authors but now including healthy newborns born by elective C-section, ONPS led to a similar small, but statistically significant reduction in HR early after birth.( Gungor 2006) Bancalari et al. conducted an RCT including 84 vigorous term newborns delivered by C-section (n=42 per treatment arm) and found a small difference in HR after the first minute after birth in those newborns receiving ONPS (148±13 beats/min) versus those that did not (137±25 beats/min, P=0.02).( Bancalari 2019) In a further RCT including 170 term newborns born through clear amniotic fluid, ONPS had no effect on HR.( Modarres 2014)

Outcome 5: Hospital length of stay

For the important outcome of hospital length of stay, we identified 3 clinical trials in newborn infants (very low quality of evidence, downgraded for serious risk of bias, very serious indirectness, and imprecision) (Chettri 2015/paper 563, Nangia 2016/paper 1346, Kumar 2019/paper 558). These studies, all evaluating the effects of ETS, documented no statistically significant differences in hospital length of stay in human infants born through meconium-stained amniotic fluid who underwent suctioning compared to those that did not (Chettri 2015/paper 563, Nangia 2016/paper 1346, Kumar 2019/paper 558). No studies were identified that evaluated this outcome for ONPS.

Treatment recommendation

For newborn dogs and cats that require resuscitation at birth but that are vigorous, we suggest using a clean, dry cloth to carefully remove fluid from around the nostrils and mouth (weak recommendation, expert opinion).

For newborn dogs and cats that are non-vigorous with excessive oropharyngeal fluid (clear or meconium-stained), we suggest gentle nasal or oropharyngeal suctioning immediately followed by PPV (weak recommendation, expert opinion).

For newborn dogs and cats that are non-vigorous with excessive oropharyngeal fluid (clear or meconium-stained), we suggest against the routine use of endotracheal suctioning (weak recommendation, very low quality of evidence).

Justification of treatment recommendation

We made the above recommendation on airway suctioning in newborn dogs and cats based on very low quality of evidence and expert opinion, and with feasibility in mind. There is no doubt that the establishment of a patent airway is a key objective early after birth as it is essential for aeration of the lungs.

Freeing the newborn puppy or kitten from fetal membranes is the first step if the dam is not able to accomplish this; this a step so obviously important that to our knowledge no research has been performed in any species to study the efficacy of this action. Next, the question arises for the rescuer team on whether it is advisable to routinely remove airway fluid by ONPS, ETS or both, and how the quantity of amniotic fluid, its quality (i.e., clear or meconium stained) and the newborn’s strength (i.e., vigorous versus non-vigorous) influence decision making. The committee considered these factors when making its treatment recommendations.

Fluid in the upper airways is typically cleared naturally and rapidly in vigorous, vocalizing newborns.( Bruckner 2021) For this reason, no active suction of the nasopharynx or oropharynx is required in most vigorous newborns, regardless of whether the kitten or puppy is born through clear or meconium-stained amniotic fluid. Standard care in this scenario includes drying and stimulation, as well as removing fluid around the nostrils and mouth with a clean, dry cloth.

We could not identify any evidence in dogs and cats however that addresses the topic, and the recommendation is solely based on expert opinion and studies conducted in a human healthcare setting. The preponderance of studies in term, healthy newborn infants, whether born vaginally or by C-section did not identify any benefit of ONPS concerning the outcomes we examined.( Bancalari 2019, Modarres 2014, Gungor 2005, Gungor 2006, Waltman 2004, Carrasco 1997, Estol 1992) In addition we found relevant evidence addressing outcomes other than the ones we initially defined. An RCT examining respiratory mechanics as primary outcome in human, healthy, term newborns with or without ONPS (n=20 per study arm) showed no significant benefit (or harm) of suctioning.( Estol, 1992) However, studies that evaluated the time until SaO2>92% in vigorous term newborn babies born vaginally or by C-section, identified that ONPS delayed the increase in oxygenation.( Gungor 2006, Gungor 2005, Carrasco 1997). In two studies by Gungor et al. that included 280 infants, all newborns reached an SaO2 of 92% by 6 minutes after birth with standard care (stimulation, drying), but none of the newborns in the ONPS groups reached the target within that time frame. (Gungor 2005, Gungor 2006) A large RCT including more than 2000 newborn infants born through meconium-stained amniotic fluid did not show a higher risk of death or meconium aspiration syndrome if no ONPS was performed at birth.( Vain 2004) Taken together, there is no evidence that routine suctioning in vigorous newborns born through clear or meconium-stained amniotic fluid is beneficial but might interfere with aeration of lungs. Our recommendation is in line with the International Liaison Committee on Resuscitation (ILCOR) that recommends against routine ONPS for vigorous newborn infants with clear or meconium-stained amniotic fluid.( Wyckoff 2020) The committee suggests the use of a dry, clean cloth to wipe excessive fluid off the surface of the newborn’s face, nostrils and muzzle as this will minimally interfere with spontaneous breathing and with aeration of the airways and lungs in these vigorous newborn puppies and kittens. Wiping was a common component of the control group interventions in the studies listed above, alongside stimulation, drying and warming. In addition, the equivalence of wiping to ONPS is supported by one study in people including 488 vigorous or non-vigorous newborns born by vaginal birth or C-section through clear amniotic fluid.( Kelleher 2013)

In non-vigorous newborns that are not or abnormally breathing, or are bradycardic, the focus is on early institution of PPV.( Wyckoff 2020) The use of ONPS alone in these non-vigorous newborns has not been well studied in humans or in veterinary species, with clinical research in people and experimental research focused on the utility of removing airway obstruction by a combination of ONPS and ETS. In the absence of any evidence of benefit of the routine use of ONPS alone in non-vigorous newborn animals, the primary concern of this intervention is the associated delay in PPV. However, the committee also acknowledges that PPV through a large amount of oropharyngeal fluid, especially if thick and meconium-stained, might compromise its efficacy. The committee therefore suggests a gentle, single, short ONPS intervention in non-vigorous newborns in which excessive upper airway fluid is present, followed immediately by PPV. The ONPS can be accomplished with a bulb syringe, a DeLee aspirator or other aspiration device in a way that avoids pharyngeal and laryngeal injury and exposure to excessive negative airway pressure.

The ILCOR treatment recommendations do not recommend routine ETS for non-vigorous newborns delivered through meconium-stained amniotic fluid, although this might be required in those newborns in which PPV is deemed not effective due to airway obstruction (Wyckoff 2020). The lack of any benefit from ETS in non-vigorous newborn infants is supported by a number of RCTs and by an experimental study in newborn lambs.(Chettri 2015/paper 563, Nangia 2016/paper 1346, Kumar 2019/paper 558, Viraraghavan 2018/paper 1339, Lakshminrusimha 2015/paper 556) Direct comparison to newborn puppies and kittens is challenged by indirectness given the small size of puppies and kittens at birth and their airways, and the differences in practice settings and resources available. In particular, endotracheal intubation, the foundation for effective, safe ETS in people is challenging in newborn puppies and kittens, and suctioning through a very small endotracheal tube appears unfeasible at present. To the committee’s knowledge, endotracheal suctioning by direct insertion of a suction catheter into the trachea has not been studied and could lead to significant airway injury and swelling, as well as derecruitment of previously aerated lung. In the absence of convincing benefit of ETS in humans and considering the significant practical challenges and potential harm for ETS in newborn puppies and kittens, the committee advises against its routine use. However, if an airway obstruction is suspected after PPV is initiated, endotracheal intubation and ETS could be considered if feasible.

Knowledge gaps

Currently, there is a critical lack of data in veterinary patients, specifically newborn puppies and kittens, regarding the use of airway clearance methodologies in vigorous or non-vigorous animals, as well as those born through clear or meconium-stained amniotic fluid. Studies that show the effect of ONPS in these populations on short- and long-term survival, the duration of PPV until breathing, and until the HR normalizes, would be important.